Herbal medicines, mainly of plant source, are invaluable source for the discovery of new therapeutic agents for all sorts of human ailments. The complex pathogenesis of stroke and multifactorial effect of herbal medic...Herbal medicines, mainly of plant source, are invaluable source for the discovery of new therapeutic agents for all sorts of human ailments. The complex pathogenesis of stroke and multifactorial effect of herbal medicine and their active constituents may suggest the promising future of natural medicine for stroke treatment. Anti-oxidant, anti-inflammatory, anti-apoptotic, neuroprotective and vascular protective effect of herbal medicines are believed to be efficacious in stroke treatment. Herbs typically have fewer reported side effects than allopathic medicine, and may be safer to use over longer period of time. Herbal medicines are believed to be more effective for the longstanding health complaints, such as stroke. Several medicinal plants and their active constituents show the promising results in laboratory research. However failure in transformation of laboratory animal research to the clinical trials has created huge challenge for the use of herbal medicine in stroke. Until and unless scientifically comprehensive evidence of the efficacy and safety of herbal medicine in ischemic stroke patients is available, efforts should be made to continue implementing treatment strategies of proven effectiveness. More consideration should be paid to natural compounds that can have extensive therapeutic time windows, perfect pharmacological targets with few side effects. Herbal medicine has excellent prospective for the treatment of ischemic stroke, but a lot of effort should be invested to transform the success of animal research to human use.展开更多
Scutellaria baicalensis Georgi is the most widely used medicinal plant in traditional Eastem medicine, especially in Chinese medicine. The major phytochemicals isolated from S. baicalensis are flavonoids, glycosides a...Scutellaria baicalensis Georgi is the most widely used medicinal plant in traditional Eastem medicine, especially in Chinese medicine. The major phytochemicals isolated from S. baicalensis are flavonoids, glycosides and their glucoronides such as baicalin, baicalein, wogonin etc. More than 30 different kinds of flavonoids are isolated from this plant. S. baicalensis and its flavonoids are reported to have several pharmacological activities, which includes anti-allergic, antioxidant, anti apoptic, anti-inflammatory effects and many more. Recently, S. baicalensis and its isolated flavonoids have been studied for their neuroprotective effects, through a variety of in vitro and in vivo models of neurodegenerative diseases, plausibly suggesting that S. baicalensis has salutary effect as a nature＇s blessing for neuroprotection. In this review, we are focousing on the neuroprotective effects of S. baicalensis and its flavonoids in ischemia or stroke-induced neuronal cell death. We aimed at compiling all the information regarding the neuroprotective effect of S. baicalensis in various experimental models of cerebral ischemia or stroke.展开更多
In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological ...In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological Administration. The analysis results show that during 1901e2014 the annual mean surface air temperature over the whole HKH has undergone a significant increasing trend. We determined the change rates in the mean temperature, mean maximum temperature, and mean minimum temperature to be 0.104 C per decade, 0.077 C per decade, and 0.176 C per decade, respectively. Most parts of the HKH have experienced a warming trend, with the largest increase occurring on the Tibetan Plateau (TP) and south of Pakistan. The trend of precipitation for the whole HKH is characterized by a slight decrease during 1901e2014. During 1961e2013, however, the trend of the annual precipitation shows a statistically significant increase, with a rate of 5.28% per decade and has a more rapid increase since the mid-1980s. Most parts of northern India and the northern TP have experienced a strong increase in the number of precipitation days (daily rainfall 1 mm), whereas Southwest China and Myanmar have experienced a declining trend in precipitation days. Compared to the trends in precipitation days, the spatial pattern of trends in the precipitation intensity seems to be more closely related to the terrain, and the higher altitude areas have shown more significant upward trends in precipitation intensity during 1961e2013.展开更多
This study reports on the effect of the addition of Glycine to Hank’s solution on the in-vitro corrosion behavior of AZ31 magnesium(Mg)alloy at 37℃and a pH of 7.4 studied by using potentiodynamic polarization(PDP),h...This study reports on the effect of the addition of Glycine to Hank’s solution on the in-vitro corrosion behavior of AZ31 magnesium(Mg)alloy at 37℃and a pH of 7.4 studied by using potentiodynamic polarization(PDP),hydrogen collecting techniques and electrochemical impedance spectroscopy(EIS)in combination with surface characterization techniques such as optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy analysis(XPS).The results reveal that adsorption of glycine initially subdues the dissolution of AZ31 Mg alloy while in long run it enhances the dissolution of the alloy due to the commencement of the chelation effect of glycine with Ca^(2+) released from hydroxyapatite.The chelation of glycine with Ca^(2+) induces the formation of cracks in the surface film which further promotes the dissolution of AZ31 Mg alloy thereby forming a porous corrosion products layer on the surface of the alloy.As a result,both the continuous dissolution of AZ31 magnesium alloy and the hydrogen evolution rate(HER)are enhanced with increasing the immersion time in Hank’s solution.展开更多
This study was attempted to reveal the changes in three hematological parameters such as blood hemoglobin,number of white blood cells(WBCs)and number of red blood cells(RBCs)and one biochemical(e.g.,glucose)parameter ...This study was attempted to reveal the changes in three hematological parameters such as blood hemoglobin,number of white blood cells(WBCs)and number of red blood cells(RBCs)and one biochemical(e.g.,glucose)parameter along with the changes in histomorphological structures of gills and kidney of Nile tilapia fry reared in saline water.Two experimental set up were used for two different age groups-5 days-after-hatch(5DAH)and 15 days-after-hatch(15DAH)-to test a novel hypothesis:if a little difference in the age during the first exposure to saline water could produce any variation in the results.They were placed into 6 plastic drums having six different salinity levels:0,5,10,15,20 and 25.After 60 days,at least 5 individuals were taken out from each drum to observe the above-hematological and histomorphological parameters.A two-way-ANOVA revealed that,except for hemoglobin,all the observed parameters have been affected the effect of age×salinity interaction(P<0.05).Between the two age groups,only the overall average glucose value and RBC count were significantly different.Among various salinity levels,only RBC and WBC counts differed significantly.Further,the mean glucose value,RBC counts and WBC count at different salinities differed significantly from the base mean value of each parameter.With regard to the histomorphological structure of the gills and kidney,various malformations were evident.Though hypertrophy,epithelial uplifting and epithelial necrosis were present as gill degenerations,hyperplasia was prevalent across almost all salinity levels.On the other hand,glomerular necrosis,pyknotic nucleus,hyaline droplets degeneration,shrinking of the glomeruli,etc.were observed in kidney structures.By assisting to understand the effects of salinity stress,all these data on tilapia fry will help to determine the prospects and scope of culturing the species in high-salinity water.展开更多
BACKGROUND Anaplastic thyroid cancer(ATC)is an aggressive,rare malignancy associated with rapid growth and metastasis,and a very poor prognosis.We investigated the clinical characteristics,survival outcomes and indepe...BACKGROUND Anaplastic thyroid cancer(ATC)is an aggressive,rare malignancy associated with rapid growth and metastasis,and a very poor prognosis.We investigated the clinical characteristics,survival outcomes and independent prognostic factors associated with anaplastic thyroid cancer.AIM To assess to what extent the interaction between age and tumor stage affects mortality.METHODS A total of 622 patients diagnosed with anaplastic thyroid cancer,between 2010 and 2017 were enrolled in our study by retrieving data from the Surveillance,Epidemiology and End Results(SEER)database.We analyzed demographics,clinical characteristics,overall mortality(OM)and cancer specific mortality(CSM)of ATC.Variables with a P value<0.1 were incorporated into the multivariate cox model to determine the independent prognostic factors.Furthermore,we analyzed the interaction between age and tumor stage on mortality.RESULTS In the multivariate analyses,the divorced/separated population had a lower OM[hazard ratio(HR)=0.63,95%CI:0.42-0.94,P<0.05]and CSM(HR=0.61,95%CI:0.40-0.92,P<0.05).OM was higher in tumors with direct extension only(HR=6.26,95%CI:1.29-30.42,P<0.05)and tumors with distant spread(HR=5.73,95%CI:1.34-24.51,P<0.05).CSM was also higher in tumors with direct extension(HR=5.05,95%CI:1.05-24.19,P<0.05)and tumors with distant spread(HR=4.57,95%CI:1.08-19.29,P<0.05).Mortality was not adversely affected by lymph node involvement.OM was lower in patients who received radiation(HR=0.66,95%CI:0.53-0.83,P<0.01),chemotherapy(HR=0.63,95%CI:0.50-0.79,P<0.01)or surgery(HR=0.53,95%CI:0.43-0.66,P<0.01).CSM was also lower in patient who received radiation(HR=0.64,95%CI:0.51-0.81,P<0.01),chemotherapy(HR=0.62,95%CI:0.50-0.78,P<0.01)or surgery(HR=0.51,95%CI:0.41-0.63,P<0.01).There was no significant interaction between age and tumor stage that affected mortality.CONCLUSION In this large US SEER database retrospective study,we found the mortality to be higher in advanced stage tumors with direct extension and distant metastasis.However,patients who r展开更多
Pesticide is one of the major inputs in modern agriculture and its uses are increasing annually. Pesticides are seen as inherently benign, in the same way that medicines are. Many local languages even use the same wor...Pesticide is one of the major inputs in modern agriculture and its uses are increasing annually. Pesticides are seen as inherently benign, in the same way that medicines are. Many local languages even use the same word for “pesticide” and “medicine</span><span style="font-family:Verdana;">”</span><span style="font-family:""><span style="font-family:Verdana;">. Along with the increasing consumption of pesticides, Highly Hazardous Pesticides (HHPs), which are more toxic are still in widespread use in Asia and constitute a substantial challenge to human health and </span><span style="font-family:Verdana;">the environment especially in low- and middle-income countries with less</span><span style="font-family:Verdana;"> resources, training and capacities to deal with them. Reducing the risks posed by HHPs has become a priority in various international chemicals manage</span><span style="font-family:Verdana;">ment policies, and many countries have started taking action accordingly</span><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The objective of the paper is to establish the national status of the use of </span><span style="font-family:Verdana;">HHPs in Asia in line with FAO/WHO criteria for HHPs and encourage deli</span><span style="font-family:Verdana;">berate consideration of mitigation options for effective management of</span><span style="font-family:Verdana;"> HHPs. This report is based on the nationally registered pesticide active ingredients and other related information obtained from Pesticide Registration Authorities of 13 Asian countries and research reports of different national and international journals. There are currently about 3557 pesticide products (active ingredients) registered in 13 Asian countries to control pests on crops and for public health uses, and 214 HHPs among the list of registered pesticides still in use in these Asian countries. An analysis of the list of registered formulated products revealed that 61 different active ingredients are includ展开更多
Datura stramonium L., a wild-growing plant of the Solanaceae family, is widely distributed and easily accessible. It contains a variety of toxic tropane alkaloids such as atropine, hyoscamine, and scopolamine. In East...Datura stramonium L., a wild-growing plant of the Solanaceae family, is widely distributed and easily accessible. It contains a variety of toxic tropane alkaloids such as atropine, hyoscamine, and scopolamine. In Eastern medicine, especially in Ayurvedic medicine, D. stramonium has been used for curing various human ailments, including ulcers, wounds, inflammation, rheumatism and gout, sciatica, bruises and swellings, fever, asthma and bronchitis, and toothache. A few previous studies have reported on the pharmacological effects of D. stramonium; however, complete information regarding the pharmacology, toxicity, ethnobotany and phytochemistry remains unclear. Ethnomedicinally, the frequent recreational abuse of D. stramonium has resulted in toxic syndromes. D. stramonium, in the form of paste or solution to relieve the local pain, may not have a deleterious effect; however, oral and systemic administration may lead to severe anticholinergic symptoms. For this reason, it is very important for individuals, mainly young people, to be aware of the toxic nature and potential risks associated with the use of this plant. This comprehensive review of D. stramonium includes information on botany, phytochemistry, pharmacology, toxicology and ethnomedicinal uses.展开更多
This paper analyses the climate projections over the Koshi river basin obtained by applying the delta method to eight CMIP5 GCMs for the RCP4.5 and RCP8.5 scenarios. The GCMs were selected to cover the full envelope o...This paper analyses the climate projections over the Koshi river basin obtained by applying the delta method to eight CMIP5 GCMs for the RCP4.5 and RCP8.5 scenarios. The GCMs were selected to cover the full envelope of possible future ranges from dry and cold to wet and warm projections. The selected coarse resolution GCM outputs were statistically downscaled to the resolution of the historical climate datasets. The scenarios were developed based on the anomaly between the present reference period (1961-1990) and the future period (2021-2050) to generate transient climate change scenarios for the eight GCMs. The analyses were carried out for the whole basin and three physiographic zones: the trans-Himalaya, high-Himalaya and middle mountains, and southern plains. Future projections show a 14% increase in rainfall during the summer monsoon season by 2050. The increase in rainfall is higher over the mountains than the plains. The meagre amount of rainfall in the winter season is projected to further decrease over both the mountain and southern plains areas of the basin for both RCPs. The basin is likely to experience warming throughout the year, although the increase in winter is likely to be higher. The highest increase in temperature is projected to be over the high Himalayan and middle mountain area, with lower increases over the trans-Himalayan and southern plains areas.展开更多
The consumption of contaminated river water can have severe effects on human health.This study aims to investigate the trace elements(TEs)content and their health risk assessment in the Badigad River Basin in the less...The consumption of contaminated river water can have severe effects on human health.This study aims to investigate the trace elements(TEs)content and their health risk assessment in the Badigad River Basin in the lesser Himalayas of Nepal.In total,44 water samples were collected from 22 different sites during the pre-monsoon and monsoon seasons,and 25 TEs were analyzed.Correlation matrix and principal component analysis(PCA)were used to analyze the potential relationship between the measured TEs and their source tracking.Furthermore,the water quality index(WQI),metal index(MI),and cancer index(CI)were evaluated.The TEs content in all samples were found to be within the WHO recommended guideline for drinking and domestic purposes.The dominancy order of the TEs was observed as Sr>Ba>Li>Rb>Zn>Cr>Sc>Mn>Ti>Cu>As>Ni>Co>U>V>Pb>Cs>Ga>Y>Tl>Th>Zr>Bi>Cd>Nb.The PCA analysis suggested that TEs could have natural,anthropogenic,and mixed origins.The WQI indicated that the river water is safe from a human health perspective.The MI suggested that Badigad River can be considered safer for drinking purposes,and the cancer index(CI)showed that all the reported TEs are at low-risk levels.The findings of this study could be useful for government agencies in developing more sustainable water management policies in the region.However,it is suggested that further investigations should be conducted in terms of other hydrogeochemical variables,including major ions,at spatiotemporal levels for the sustainability of the river basin.展开更多
The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, espe...The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, especially during the global warming hiatus period. The rapid warming cause solid state water (snow, ice, glacier, and permafrost) to shrink, leading to increase in meltwater and there have been found more frequent incidences of flash floods, landslides, livestock diseases, and other disasters in the HKH region. Increasing awareness of climate change over the HKH region is reached a consensus. Meanwhile, the HKH region is often referred to as the water towers of Asia as many highaltitude regions store its water in the form of snow and/or glacier, feeding ten major large rivers in Asia. Therefore, the impacts of climate change on water availability in these river basins have huge influences on the livelihood of large number of population, especially in downstream regions. However, the scarcity of basic hydro-meteorological observations particularly in high-altitude regions of HKH limits rigorous analysis of climate change. Most studies used reanalysis data and/or model-reconstructed products to explore the spatial and temporal characteristics of hydro-meteorological processes, especially for extreme events. In this study, we review recent climate change in the HKH region, and the scientific challenges and research recommendations are suggested for this high-altitude area.展开更多
The high mountains of Hindu-Kush Karakoram and Himalaya(HKKH) contain a large volume of snow and ice, which are the primary sources of water for the entire mountainous population of HKKH. Thus, knowledge of these avai...The high mountains of Hindu-Kush Karakoram and Himalaya(HKKH) contain a large volume of snow and ice, which are the primary sources of water for the entire mountainous population of HKKH. Thus, knowledge of these available resources is very important in relation to their sustainable use. A Modified Positive Degree Day Model was used to simulate daily discharge with the contribution of snow and ice melt from the Shigar River Basin, Central Karakoram, Pakistan. The basin covers an area of 6,921 km2 with an elevation range of 2,204 to 8,611 m a.s.l.. Forty percent of the total area is glaciated among which 20% is covered by debris and remaining 80% by clean ice and permanent snow. To simulate daily discharge, the entire basin was divided into 26 altitude belts. Remotely sensed land cover types are derived by classifying Landsat images of 2009. Daily temperature and precipitation from Skardu meteorological station is used to calibrate the glacio-hydrological model as an input variable after correlating data with the Shigar station data(r=0.88). Local temperature lapse rate of 0.0075 °C/m is used. 2 °C critical temperature is used to separate rain and snow from precipitation. The model is calibrated for 1988~1991 and validated for 1992~1997. The model shows a good Nash-Sutcliffe efficiency and volume difference in calibration(0.86% and 0.90%) and validation(0.78% and 6.85%). Contribution of snow and ice melt in discharge is 32.37% in calibration period and 33.01% is validation period. The model is also used to predict future hydrological regime up to 2099 by using CORDEX South Asia RCM considering RCP4.5 and RCP8.5 climate scenarios.Predicted future snow and ice melt contributions in both RCP4.5 and RCP8.5 are 36% and 37%, respectively. Temperature seems to be more sensitive as compared to other input variables, which is why the contribution of snow and ice in discharge varies significantly throughout the whole century.展开更多
AZ31 magnesium（Mg） alloy was potentiostatic polarized in 0.1 M deaerated KF solution with pH 7.5 from-0.4 V to-1.4 V with an interval of-0.2 V. The polarization process was described by the potentiostatic current de...AZ31 magnesium（Mg） alloy was potentiostatic polarized in 0.1 M deaerated KF solution with pH 7.5 from-0.4 V to-1.4 V with an interval of-0.2 V. The polarization process was described by the potentiostatic current decay. The resultant film was analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and electrochemical impedance spectroscopy（EIS）. The results demonstrated that the deposited film included a Mg（OH）2/MgF2 containing inner layer and a Mg（OH）-2/MgF2/KMgF3 comprising outer layer. The high polarized potential produced high content of MgF2 but low content of KMgF3 and thin film. Conversely, the low polarized potential produced small content of MgF2 but high content of KMgF3 and thick film. The optimal corrosion resistance of the deposited film was obtained at-1.4 V, which was closely related with the content of MgF2 and KMgF3 and the film thickness.展开更多
Understanding the upstream-downstream linkages in hydrological processes is essential for water resources planning in river basins.Although there are many studies of individual aspects of these processes in the Himala...Understanding the upstream-downstream linkages in hydrological processes is essential for water resources planning in river basins.Although there are many studies of individual aspects of these processes in the Himalayan region,studies along the length of the basins are limited.This study summarizes the present state of knowledge about linkages in hydrological processes between upstream and downstream areas of river basins in the Himalayan region based on a literature review.The paper studies the linkages between the changes in the physical environment of upstream areas(land use,snow storage,and soil erosion)and of climate change on the downstream water availability,flood and dry season flow,and erosion and sedimentation.It is argued that these linkages are complex due to the extreme altitudinal range associated with the young and fragile geology,extreme seasonal and spatial variation in rainfall,and diversity of anthropogenic processes.Based on the findings,the paper concludes that integrated systems analysis is required to understand the holistic complexity of upstream-downstream linkages of hydrological processes in the river basin context.The integrated land and water resources management(ILWRM)approach can be instrumental in developing adaptive solutions to problems and can also enable stakeholders of upstream and downstream areas with various interests and needs to work together for the better utilization and management of land and water resources.As a part of this,the specific circumstances of the upstream communities,who live in fragile and inaccessible mountain areas with limited resource opportunities,should be taken into account so that incentive mechanisms can be established to encourage and acknowledge their contribution.展开更多
This study assessed the regional climate models (RCMs) employed in the Coordinated Regional climate Downscaling Experiment (CORDEX) South Asia framework to investigate the qualitative aspects of future change in seaso...This study assessed the regional climate models (RCMs) employed in the Coordinated Regional climate Downscaling Experiment (CORDEX) South Asia framework to investigate the qualitative aspects of future change in seasonal mean near surface air temperature and precipitation over the Hindu Kush Himalayan (HKH) region. These RCMs downscaled a subset of atmosphere ocean coupled global climate models (AOGCMs) in the Coupled Model Intercomparison Project phase 5 (CMIP5) to higher 50 km spatial resolution over a large domain covering South Asia for two representation concentration pathways (RCP4.5 and RCP8.5) future scenarios. The analysis specifically examined and evaluated multi-model and multi-scenario climate change projections over the hilly sub-regions within HKH for the near-future (2036e2065) and far-future (2066e2095) periods. The downscaled multi-RCMs provide relatively better confidence than their driving AOGCMs in projecting the magnitude of seasonal warming for the hilly sub-region within the Karakoram and northwestern Himalaya, with higher projected change of 5.4 C during winter than of 4.9 C during summer monsoon season by the end of 21st century under the high-end emissions (RCP8.5) scenario. There is less agreement among these RCMs on the magnitude of the projected warming over the other sub-regions within HKH for both seasons, particularly associated with higher RCM uncertainty for the hilly sub-region within the central Himalaya. The downscaled multi-RCMs show good consensus and low RCM uncertainty in projecting that the summer monsoon precipitation will intensify by about 22% in the hilly subregion within the southeastern Himalaya and Tibetan Plateau for the far-future period under the RCP8.5 scenario. There is low confidence in the projected changes in the summer monsoon and winter season precipitation over the central Himalaya and in the Karakoram and northwestern Himalaya due to poor consensus and moderate to high RCM uncertainty among the downscaled multi-RCMs. Finally, the RCM related uncerta展开更多
In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electro...In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electron emission from dust grains has been considered as the source of positive dust charging. As secondary emission current depends on the flux of primary electrons, nonthermality of primary electrons changes the expression of secondary emission current from that of earlier work where primary electrons were thermal. Expression of nonthermal electron current flowing to the positively charged dust grains and consequently the expression of secondary electron current flowing out of the dust grains have been first time calculated in this paper, whereas the expression for nonthermal ion current flowing to the positively charged dust grains is present in existing literature. Dispersion relation of dust acoustic wave has been derived. From this dispersion relation real frequency and growth rate of the wave have been calculated. Results have been plotted for different strength of nonthermalities of electrons and ions.展开更多
OBJECTIVE:To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and invitromodels of cerebral ischemia.METHODS:As an in vitro model,oxygen glucose deprivation followed by reoxygenat...OBJECTIVE:To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and invitromodels of cerebral ischemia.METHODS:As an in vitro model,oxygen glucose deprivation followed by reoxygenation(OGD-R)and hydrogen peroxide(H2O2)induced cellular damage in rat pheochromocytoma(PC12)cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival.For in vivo,occlusion of left middle cerebral artery on rats was carried out as a focal cerebral ischemic model.RESULTS:Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H2O2by 68%and 91.4%respectively.Fructus Chebulae also de-creases the cerebral infarct volume by 39%and extent of hemisphere swelling from 17%in control group to 10%in FructusChebulaetreated group.CONCLUSION:Fructus Chebulae,as a traditional medicine,can rescue the neuronal cell death against ischemia related damage.The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.展开更多
The multi-model assessment of glacio-hydrological regimes can enhance our understanding of glacier response to climate change.This improved knowledge can uplift our computing abilities to estimate the contributing com...The multi-model assessment of glacio-hydrological regimes can enhance our understanding of glacier response to climate change.This improved knowledge can uplift our computing abilities to estimate the contributing components of the river discharge.This study examined and compared the hydrological responses in the glacier-dominated Shigar River basin(SRB)under various climatic scenarios using a semi-distributed Modified Positive Degree Day Model(MPDDM)and a distributed Glacio-hydrological Degree-day Model(GDM).Both glacio-hydrological models were calibrated and validated against the observed hydro-meteorological data from 1988–1992 and 1993–1997.Temperature and precipitation data from Shigar and Skardu meteorological stations were used along with field estimated degree-day factor,temperature,and precipitation gradients.The results from both models indicate that the snow and ice melt are vital contributors to sustain river flow in the catchment.However,MPDDM estimated 68%of rain and baseflow contribution to annual river runoff despite low precipitation during the summer monsoon,while GDM estimated 14%rain and baseflow contribution.Likewise,MPDDM calculated 32%,and GDM generated 86%of the annual river runoff from snow and ice melt.MPDDM simulated river discharge with 0.86 and 0.78 NSE for calibration and validation,respectively.Similarly,GDM simulated river discharge with improved accuracy of 0.87 for calibration and 0.84 NSE for the validation period.The snow and ice melt is significant in sustaining river flow in the SRB,and substantial changes in melt characteristics of snow and ice are expected to have severe consequences on seasonal water availability.Based on the sensitivity analysis,both models’outputs are highly sensitive to the variation in temperature.Furthermore,compared to MPDDM,GDM simulated considerable variation in the river discharge in climate scenarios,RCP4.5 and 8.5,mainly due to the higher sensitivity of GDM model outputs to temperature change.The integration of an updated melt module and t展开更多
A detailed analytical study of the physico-chemical parameters of melt water draining from glaciers of Langtang Valley with an elevation ranging from 1395 m a s l to 4200 m a s l in Rasuwa district, Nepal was carried ...A detailed analytical study of the physico-chemical parameters of melt water draining from glaciers of Langtang Valley with an elevation ranging from 1395 m a s l to 4200 m a s l in Rasuwa district, Nepal was carried out in order to study the seasonal and altitudinal variation in hydro-chemistry along the Langtang River and glacial melts from the Lirung and the Khimsung Glaciers. The study was carried out during 6 - 10 April and 30 June-3 July, 2014 at 11 sites. A total of 22 composite samples were collected. The concentration of cations and anions of the Langtang Valley were found in the order Ca2+ > K+ > Na+ > Mg2+ and , respectively. Significant seasonal variation in electrical conductivity (EC), turbidity, dissolved oxygen (DO), calcium (Ca), sodium (Na), magnesium (Mg), chloride (Cl), sulphate (SO4) and total phosphorus (TP-PO4) and altitudinal variation in EC, total dissolved solids (TDS), DO and Na was found out. The concentrations of the heavy metals (As, Al, Mn, Zn, Cd, Cr) were below the detection limit except Fe (0.5 to 18.1 mg/l), which was highly variable. Calcium carbonate weathering was found out to be the major source of dissolved ions in the region. The elemental ratios (Ca/Si and K/Na) were typical of glacial melt water and the low Na/Cl and K/Cl ratios indicated major contribution from atmospheric precipitation to the observed dissolved ions of melt waters. The study showed an increase in the concentration of cations as compared to previous studies, which could be attributed to increasing weathering rates due to temperature increase. Elevated concentration of NO3 and TP-PO4 compared to previous studies show the effect of human impact in the region. Differences in the melt water composition between the debris covered and clean type glacier was found out.展开更多
文摘Herbal medicines, mainly of plant source, are invaluable source for the discovery of new therapeutic agents for all sorts of human ailments. The complex pathogenesis of stroke and multifactorial effect of herbal medicine and their active constituents may suggest the promising future of natural medicine for stroke treatment. Anti-oxidant, anti-inflammatory, anti-apoptotic, neuroprotective and vascular protective effect of herbal medicines are believed to be efficacious in stroke treatment. Herbs typically have fewer reported side effects than allopathic medicine, and may be safer to use over longer period of time. Herbal medicines are believed to be more effective for the longstanding health complaints, such as stroke. Several medicinal plants and their active constituents show the promising results in laboratory research. However failure in transformation of laboratory animal research to the clinical trials has created huge challenge for the use of herbal medicine in stroke. Until and unless scientifically comprehensive evidence of the efficacy and safety of herbal medicine in ischemic stroke patients is available, efforts should be made to continue implementing treatment strategies of proven effectiveness. More consideration should be paid to natural compounds that can have extensive therapeutic time windows, perfect pharmacological targets with few side effects. Herbal medicine has excellent prospective for the treatment of ischemic stroke, but a lot of effort should be invested to transform the success of animal research to human use.
文摘Scutellaria baicalensis Georgi is the most widely used medicinal plant in traditional Eastem medicine, especially in Chinese medicine. The major phytochemicals isolated from S. baicalensis are flavonoids, glycosides and their glucoronides such as baicalin, baicalein, wogonin etc. More than 30 different kinds of flavonoids are isolated from this plant. S. baicalensis and its flavonoids are reported to have several pharmacological activities, which includes anti-allergic, antioxidant, anti apoptic, anti-inflammatory effects and many more. Recently, S. baicalensis and its isolated flavonoids have been studied for their neuroprotective effects, through a variety of in vitro and in vivo models of neurodegenerative diseases, plausibly suggesting that S. baicalensis has salutary effect as a nature＇s blessing for neuroprotection. In this review, we are focousing on the neuroprotective effects of S. baicalensis and its flavonoids in ischemia or stroke-induced neuronal cell death. We aimed at compiling all the information regarding the neuroprotective effect of S. baicalensis in various experimental models of cerebral ischemia or stroke.
文摘In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological Administration. The analysis results show that during 1901e2014 the annual mean surface air temperature over the whole HKH has undergone a significant increasing trend. We determined the change rates in the mean temperature, mean maximum temperature, and mean minimum temperature to be 0.104 C per decade, 0.077 C per decade, and 0.176 C per decade, respectively. Most parts of the HKH have experienced a warming trend, with the largest increase occurring on the Tibetan Plateau (TP) and south of Pakistan. The trend of precipitation for the whole HKH is characterized by a slight decrease during 1901e2014. During 1961e2013, however, the trend of the annual precipitation shows a statistically significant increase, with a rate of 5.28% per decade and has a more rapid increase since the mid-1980s. Most parts of northern India and the northern TP have experienced a strong increase in the number of precipitation days (daily rainfall 1 mm), whereas Southwest China and Myanmar have experienced a declining trend in precipitation days. Compared to the trends in precipitation days, the spatial pattern of trends in the precipitation intensity seems to be more closely related to the terrain, and the higher altitude areas have shown more significant upward trends in precipitation intensity during 1961e2013.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51701221 and 51801219)the National Key Research and Development Program of China(No.2017YFB0702302)。
文摘This study reports on the effect of the addition of Glycine to Hank’s solution on the in-vitro corrosion behavior of AZ31 magnesium(Mg)alloy at 37℃and a pH of 7.4 studied by using potentiodynamic polarization(PDP),hydrogen collecting techniques and electrochemical impedance spectroscopy(EIS)in combination with surface characterization techniques such as optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy analysis(XPS).The results reveal that adsorption of glycine initially subdues the dissolution of AZ31 Mg alloy while in long run it enhances the dissolution of the alloy due to the commencement of the chelation effect of glycine with Ca^(2+) released from hydroxyapatite.The chelation of glycine with Ca^(2+) induces the formation of cracks in the surface film which further promotes the dissolution of AZ31 Mg alloy thereby forming a porous corrosion products layer on the surface of the alloy.As a result,both the continuous dissolution of AZ31 magnesium alloy and the hydrogen evolution rate(HER)are enhanced with increasing the immersion time in Hank’s solution.
基金supported by a grant of BAS-USDA Program Project(BAS-USDA-PALS-BAU-FI-43)partially supported from Ministry of Education(MoE),Bangladesh to MSI.
文摘This study was attempted to reveal the changes in three hematological parameters such as blood hemoglobin,number of white blood cells(WBCs)and number of red blood cells(RBCs)and one biochemical(e.g.,glucose)parameter along with the changes in histomorphological structures of gills and kidney of Nile tilapia fry reared in saline water.Two experimental set up were used for two different age groups-5 days-after-hatch(5DAH)and 15 days-after-hatch(15DAH)-to test a novel hypothesis:if a little difference in the age during the first exposure to saline water could produce any variation in the results.They were placed into 6 plastic drums having six different salinity levels:0,5,10,15,20 and 25.After 60 days,at least 5 individuals were taken out from each drum to observe the above-hematological and histomorphological parameters.A two-way-ANOVA revealed that,except for hemoglobin,all the observed parameters have been affected the effect of age×salinity interaction(P<0.05).Between the two age groups,only the overall average glucose value and RBC count were significantly different.Among various salinity levels,only RBC and WBC counts differed significantly.Further,the mean glucose value,RBC counts and WBC count at different salinities differed significantly from the base mean value of each parameter.With regard to the histomorphological structure of the gills and kidney,various malformations were evident.Though hypertrophy,epithelial uplifting and epithelial necrosis were present as gill degenerations,hyperplasia was prevalent across almost all salinity levels.On the other hand,glomerular necrosis,pyknotic nucleus,hyaline droplets degeneration,shrinking of the glomeruli,etc.were observed in kidney structures.By assisting to understand the effects of salinity stress,all these data on tilapia fry will help to determine the prospects and scope of culturing the species in high-salinity water.
文摘BACKGROUND Anaplastic thyroid cancer(ATC)is an aggressive,rare malignancy associated with rapid growth and metastasis,and a very poor prognosis.We investigated the clinical characteristics,survival outcomes and independent prognostic factors associated with anaplastic thyroid cancer.AIM To assess to what extent the interaction between age and tumor stage affects mortality.METHODS A total of 622 patients diagnosed with anaplastic thyroid cancer,between 2010 and 2017 were enrolled in our study by retrieving data from the Surveillance,Epidemiology and End Results(SEER)database.We analyzed demographics,clinical characteristics,overall mortality(OM)and cancer specific mortality(CSM)of ATC.Variables with a P value<0.1 were incorporated into the multivariate cox model to determine the independent prognostic factors.Furthermore,we analyzed the interaction between age and tumor stage on mortality.RESULTS In the multivariate analyses,the divorced/separated population had a lower OM[hazard ratio(HR)=0.63,95%CI:0.42-0.94,P<0.05]and CSM(HR=0.61,95%CI:0.40-0.92,P<0.05).OM was higher in tumors with direct extension only(HR=6.26,95%CI:1.29-30.42,P<0.05)and tumors with distant spread(HR=5.73,95%CI:1.34-24.51,P<0.05).CSM was also higher in tumors with direct extension(HR=5.05,95%CI:1.05-24.19,P<0.05)and tumors with distant spread(HR=4.57,95%CI:1.08-19.29,P<0.05).Mortality was not adversely affected by lymph node involvement.OM was lower in patients who received radiation(HR=0.66,95%CI:0.53-0.83,P<0.01),chemotherapy(HR=0.63,95%CI:0.50-0.79,P<0.01)or surgery(HR=0.53,95%CI:0.43-0.66,P<0.01).CSM was also lower in patient who received radiation(HR=0.64,95%CI:0.51-0.81,P<0.01),chemotherapy(HR=0.62,95%CI:0.50-0.78,P<0.01)or surgery(HR=0.51,95%CI:0.41-0.63,P<0.01).There was no significant interaction between age and tumor stage that affected mortality.CONCLUSION In this large US SEER database retrospective study,we found the mortality to be higher in advanced stage tumors with direct extension and distant metastasis.However,patients who r
文摘Pesticide is one of the major inputs in modern agriculture and its uses are increasing annually. Pesticides are seen as inherently benign, in the same way that medicines are. Many local languages even use the same word for “pesticide” and “medicine</span><span style="font-family:Verdana;">”</span><span style="font-family:""><span style="font-family:Verdana;">. Along with the increasing consumption of pesticides, Highly Hazardous Pesticides (HHPs), which are more toxic are still in widespread use in Asia and constitute a substantial challenge to human health and </span><span style="font-family:Verdana;">the environment especially in low- and middle-income countries with less</span><span style="font-family:Verdana;"> resources, training and capacities to deal with them. Reducing the risks posed by HHPs has become a priority in various international chemicals manage</span><span style="font-family:Verdana;">ment policies, and many countries have started taking action accordingly</span><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The objective of the paper is to establish the national status of the use of </span><span style="font-family:Verdana;">HHPs in Asia in line with FAO/WHO criteria for HHPs and encourage deli</span><span style="font-family:Verdana;">berate consideration of mitigation options for effective management of</span><span style="font-family:Verdana;"> HHPs. This report is based on the nationally registered pesticide active ingredients and other related information obtained from Pesticide Registration Authorities of 13 Asian countries and research reports of different national and international journals. There are currently about 3557 pesticide products (active ingredients) registered in 13 Asian countries to control pests on crops and for public health uses, and 214 HHPs among the list of registered pesticides still in use in these Asian countries. An analysis of the list of registered formulated products revealed that 61 different active ingredients are includ
基金supported by Dr. Katsuko Komatsu Award of Year 2008, Japan
文摘Datura stramonium L., a wild-growing plant of the Solanaceae family, is widely distributed and easily accessible. It contains a variety of toxic tropane alkaloids such as atropine, hyoscamine, and scopolamine. In Eastern medicine, especially in Ayurvedic medicine, D. stramonium has been used for curing various human ailments, including ulcers, wounds, inflammation, rheumatism and gout, sciatica, bruises and swellings, fever, asthma and bronchitis, and toothache. A few previous studies have reported on the pharmacological effects of D. stramonium; however, complete information regarding the pharmacology, toxicity, ethnobotany and phytochemistry remains unclear. Ethnomedicinally, the frequent recreational abuse of D. stramonium has resulted in toxic syndromes. D. stramonium, in the form of paste or solution to relieve the local pain, may not have a deleterious effect; however, oral and systemic administration may lead to severe anticholinergic symptoms. For this reason, it is very important for individuals, mainly young people, to be aware of the toxic nature and potential risks associated with the use of this plant. This comprehensive review of D. stramonium includes information on botany, phytochemistry, pharmacology, toxicology and ethnomedicinal uses.
文摘This paper analyses the climate projections over the Koshi river basin obtained by applying the delta method to eight CMIP5 GCMs for the RCP4.5 and RCP8.5 scenarios. The GCMs were selected to cover the full envelope of possible future ranges from dry and cold to wet and warm projections. The selected coarse resolution GCM outputs were statistically downscaled to the resolution of the historical climate datasets. The scenarios were developed based on the anomaly between the present reference period (1961-1990) and the future period (2021-2050) to generate transient climate change scenarios for the eight GCMs. The analyses were carried out for the whole basin and three physiographic zones: the trans-Himalaya, high-Himalaya and middle mountains, and southern plains. Future projections show a 14% increase in rainfall during the summer monsoon season by 2050. The increase in rainfall is higher over the mountains than the plains. The meagre amount of rainfall in the winter season is projected to further decrease over both the mountain and southern plains areas of the basin for both RCPs. The basin is likely to experience warming throughout the year, although the increase in winter is likely to be higher. The highest increase in temperature is projected to be over the high Himalayan and middle mountain area, with lower increases over the trans-Himalayan and southern plains areas.
文摘The consumption of contaminated river water can have severe effects on human health.This study aims to investigate the trace elements(TEs)content and their health risk assessment in the Badigad River Basin in the lesser Himalayas of Nepal.In total,44 water samples were collected from 22 different sites during the pre-monsoon and monsoon seasons,and 25 TEs were analyzed.Correlation matrix and principal component analysis(PCA)were used to analyze the potential relationship between the measured TEs and their source tracking.Furthermore,the water quality index(WQI),metal index(MI),and cancer index(CI)were evaluated.The TEs content in all samples were found to be within the WHO recommended guideline for drinking and domestic purposes.The dominancy order of the TEs was observed as Sr>Ba>Li>Rb>Zn>Cr>Sc>Mn>Ti>Cu>As>Ni>Co>U>V>Pb>Cs>Ga>Y>Tl>Th>Zr>Bi>Cd>Nb.The PCA analysis suggested that TEs could have natural,anthropogenic,and mixed origins.The WQI indicated that the river water is safe from a human health perspective.The MI suggested that Badigad River can be considered safer for drinking purposes,and the cancer index(CI)showed that all the reported TEs are at low-risk levels.The findings of this study could be useful for government agencies in developing more sustainable water management policies in the region.However,it is suggested that further investigations should be conducted in terms of other hydrogeochemical variables,including major ions,at spatiotemporal levels for the sustainability of the river basin.
文摘The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, especially during the global warming hiatus period. The rapid warming cause solid state water (snow, ice, glacier, and permafrost) to shrink, leading to increase in meltwater and there have been found more frequent incidences of flash floods, landslides, livestock diseases, and other disasters in the HKH region. Increasing awareness of climate change over the HKH region is reached a consensus. Meanwhile, the HKH region is often referred to as the water towers of Asia as many highaltitude regions store its water in the form of snow and/or glacier, feeding ten major large rivers in Asia. Therefore, the impacts of climate change on water availability in these river basins have huge influences on the livelihood of large number of population, especially in downstream regions. However, the scarcity of basic hydro-meteorological observations particularly in high-altitude regions of HKH limits rigorous analysis of climate change. Most studies used reanalysis data and/or model-reconstructed products to explore the spatial and temporal characteristics of hydro-meteorological processes, especially for extreme events. In this study, we review recent climate change in the HKH region, and the scientific challenges and research recommendations are suggested for this high-altitude area.
文摘The high mountains of Hindu-Kush Karakoram and Himalaya(HKKH) contain a large volume of snow and ice, which are the primary sources of water for the entire mountainous population of HKKH. Thus, knowledge of these available resources is very important in relation to their sustainable use. A Modified Positive Degree Day Model was used to simulate daily discharge with the contribution of snow and ice melt from the Shigar River Basin, Central Karakoram, Pakistan. The basin covers an area of 6,921 km2 with an elevation range of 2,204 to 8,611 m a.s.l.. Forty percent of the total area is glaciated among which 20% is covered by debris and remaining 80% by clean ice and permanent snow. To simulate daily discharge, the entire basin was divided into 26 altitude belts. Remotely sensed land cover types are derived by classifying Landsat images of 2009. Daily temperature and precipitation from Skardu meteorological station is used to calibrate the glacio-hydrological model as an input variable after correlating data with the Shigar station data(r=0.88). Local temperature lapse rate of 0.0075 °C/m is used. 2 °C critical temperature is used to separate rain and snow from precipitation. The model is calibrated for 1988~1991 and validated for 1992~1997. The model shows a good Nash-Sutcliffe efficiency and volume difference in calibration(0.86% and 0.90%) and validation(0.78% and 6.85%). Contribution of snow and ice melt in discharge is 32.37% in calibration period and 33.01% is validation period. The model is also used to predict future hydrological regime up to 2099 by using CORDEX South Asia RCM considering RCP4.5 and RCP8.5 climate scenarios.Predicted future snow and ice melt contributions in both RCP4.5 and RCP8.5 are 36% and 37%, respectively. Temperature seems to be more sensitive as compared to other input variables, which is why the contribution of snow and ice in discharge varies significantly throughout the whole century.
基金supported financially by the National Natural Science Foundation of China (No. 51701221)
文摘AZ31 magnesium（Mg） alloy was potentiostatic polarized in 0.1 M deaerated KF solution with pH 7.5 from-0.4 V to-1.4 V with an interval of-0.2 V. The polarization process was described by the potentiostatic current decay. The resultant film was analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and electrochemical impedance spectroscopy（EIS）. The results demonstrated that the deposited film included a Mg（OH）2/MgF2 containing inner layer and a Mg（OH）-2/MgF2/KMgF3 comprising outer layer. The high polarized potential produced high content of MgF2 but low content of KMgF3 and thin film. Conversely, the low polarized potential produced small content of MgF2 but high content of KMgF3 and thick film. The optimal corrosion resistance of the deposited film was obtained at-1.4 V, which was closely related with the content of MgF2 and KMgF3 and the film thickness.
基金This study was funded in part by the Federal Ministry of Education and Research(BMBF)Germany,who provided research funds to S.Nepal under the International Postgraduate Studies in Water Technologies(IPSWaT)program+1 种基金in part by the Koshi Basin Programme at the International Centre for Integrated Mountain Development(ICIMOD)which is supported by the Australian Government through the Sustainable Development Investment Portfolio for South Asia.We are grateful to A.Mukherji for her critical inputs and suggestions on the paper.Thanks to A.Beatrice Murray for editing the language of the manuscript.
文摘Understanding the upstream-downstream linkages in hydrological processes is essential for water resources planning in river basins.Although there are many studies of individual aspects of these processes in the Himalayan region,studies along the length of the basins are limited.This study summarizes the present state of knowledge about linkages in hydrological processes between upstream and downstream areas of river basins in the Himalayan region based on a literature review.The paper studies the linkages between the changes in the physical environment of upstream areas(land use,snow storage,and soil erosion)and of climate change on the downstream water availability,flood and dry season flow,and erosion and sedimentation.It is argued that these linkages are complex due to the extreme altitudinal range associated with the young and fragile geology,extreme seasonal and spatial variation in rainfall,and diversity of anthropogenic processes.Based on the findings,the paper concludes that integrated systems analysis is required to understand the holistic complexity of upstream-downstream linkages of hydrological processes in the river basin context.The integrated land and water resources management(ILWRM)approach can be instrumental in developing adaptive solutions to problems and can also enable stakeholders of upstream and downstream areas with various interests and needs to work together for the better utilization and management of land and water resources.As a part of this,the specific circumstances of the upstream communities,who live in fragile and inaccessible mountain areas with limited resource opportunities,should be taken into account so that incentive mechanisms can be established to encourage and acknowledge their contribution.
文摘This study assessed the regional climate models (RCMs) employed in the Coordinated Regional climate Downscaling Experiment (CORDEX) South Asia framework to investigate the qualitative aspects of future change in seasonal mean near surface air temperature and precipitation over the Hindu Kush Himalayan (HKH) region. These RCMs downscaled a subset of atmosphere ocean coupled global climate models (AOGCMs) in the Coupled Model Intercomparison Project phase 5 (CMIP5) to higher 50 km spatial resolution over a large domain covering South Asia for two representation concentration pathways (RCP4.5 and RCP8.5) future scenarios. The analysis specifically examined and evaluated multi-model and multi-scenario climate change projections over the hilly sub-regions within HKH for the near-future (2036e2065) and far-future (2066e2095) periods. The downscaled multi-RCMs provide relatively better confidence than their driving AOGCMs in projecting the magnitude of seasonal warming for the hilly sub-region within the Karakoram and northwestern Himalaya, with higher projected change of 5.4 C during winter than of 4.9 C during summer monsoon season by the end of 21st century under the high-end emissions (RCP8.5) scenario. There is less agreement among these RCMs on the magnitude of the projected warming over the other sub-regions within HKH for both seasons, particularly associated with higher RCM uncertainty for the hilly sub-region within the central Himalaya. The downscaled multi-RCMs show good consensus and low RCM uncertainty in projecting that the summer monsoon precipitation will intensify by about 22% in the hilly subregion within the southeastern Himalaya and Tibetan Plateau for the far-future period under the RCP8.5 scenario. There is low confidence in the projected changes in the summer monsoon and winter season precipitation over the central Himalaya and in the Karakoram and northwestern Himalaya due to poor consensus and moderate to high RCM uncertainty among the downscaled multi-RCMs. Finally, the RCM related uncerta
文摘In this paper we have developed a model to study the role of both electron and ion nonthermalities on dust acoustic wave propagation in a complex plasma in presence of positively charged dust grains. Secondary electron emission from dust grains has been considered as the source of positive dust charging. As secondary emission current depends on the flux of primary electrons, nonthermality of primary electrons changes the expression of secondary emission current from that of earlier work where primary electrons were thermal. Expression of nonthermal electron current flowing to the positively charged dust grains and consequently the expression of secondary electron current flowing out of the dust grains have been first time calculated in this paper, whereas the expression for nonthermal ion current flowing to the positively charged dust grains is present in existing literature. Dispersion relation of dust acoustic wave has been derived. From this dispersion relation real frequency and growth rate of the wave have been calculated. Results have been plotted for different strength of nonthermalities of electrons and ions.
基金Supported by a Grant of the Korean Health Technology Re-search and Development Project,Ministry of Health&Wel-fare(B110072)National Research Foundation of Korea Funded by the Ministry of Science,Information and Commu-nication Technology&Future Planning,Republic of Korea(2012M3A9C4048795)
文摘OBJECTIVE:To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and invitromodels of cerebral ischemia.METHODS:As an in vitro model,oxygen glucose deprivation followed by reoxygenation(OGD-R)and hydrogen peroxide(H2O2)induced cellular damage in rat pheochromocytoma(PC12)cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival.For in vivo,occlusion of left middle cerebral artery on rats was carried out as a focal cerebral ischemic model.RESULTS:Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H2O2by 68%and 91.4%respectively.Fructus Chebulae also de-creases the cerebral infarct volume by 39%and extent of hemisphere swelling from 17%in control group to 10%in FructusChebulaetreated group.CONCLUSION:Fructus Chebulae,as a traditional medicine,can rescue the neuronal cell death against ischemia related damage.The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.
基金the Himalayan Cryosphere, Climate and Disaster Research Center (HiCCDRC), Kathmandu University for constant support throughout the researchfunded by The Second Tibetan Plateau Scientific Expedition and Research Program (STEP)(Grant No. 2019QZKK0904)+3 种基金supported by the Comprehensive Investigation and Assessment of Natural Hazards in China-Pakistan Economic Corridor (Grant No. 2018FY100500)Ministry of Science and Technology Basic Resources Survey Project (2018FY100506)International Science andTechnology Cooperation Program of China (No. 2018YFE0100100)the National Natural Science Foundation of China (41925030 and 41661144028)
文摘The multi-model assessment of glacio-hydrological regimes can enhance our understanding of glacier response to climate change.This improved knowledge can uplift our computing abilities to estimate the contributing components of the river discharge.This study examined and compared the hydrological responses in the glacier-dominated Shigar River basin(SRB)under various climatic scenarios using a semi-distributed Modified Positive Degree Day Model(MPDDM)and a distributed Glacio-hydrological Degree-day Model(GDM).Both glacio-hydrological models were calibrated and validated against the observed hydro-meteorological data from 1988–1992 and 1993–1997.Temperature and precipitation data from Shigar and Skardu meteorological stations were used along with field estimated degree-day factor,temperature,and precipitation gradients.The results from both models indicate that the snow and ice melt are vital contributors to sustain river flow in the catchment.However,MPDDM estimated 68%of rain and baseflow contribution to annual river runoff despite low precipitation during the summer monsoon,while GDM estimated 14%rain and baseflow contribution.Likewise,MPDDM calculated 32%,and GDM generated 86%of the annual river runoff from snow and ice melt.MPDDM simulated river discharge with 0.86 and 0.78 NSE for calibration and validation,respectively.Similarly,GDM simulated river discharge with improved accuracy of 0.87 for calibration and 0.84 NSE for the validation period.The snow and ice melt is significant in sustaining river flow in the SRB,and substantial changes in melt characteristics of snow and ice are expected to have severe consequences on seasonal water availability.Based on the sensitivity analysis,both models’outputs are highly sensitive to the variation in temperature.Furthermore,compared to MPDDM,GDM simulated considerable variation in the river discharge in climate scenarios,RCP4.5 and 8.5,mainly due to the higher sensitivity of GDM model outputs to temperature change.The integration of an updated melt module and t
文摘A detailed analytical study of the physico-chemical parameters of melt water draining from glaciers of Langtang Valley with an elevation ranging from 1395 m a s l to 4200 m a s l in Rasuwa district, Nepal was carried out in order to study the seasonal and altitudinal variation in hydro-chemistry along the Langtang River and glacial melts from the Lirung and the Khimsung Glaciers. The study was carried out during 6 - 10 April and 30 June-3 July, 2014 at 11 sites. A total of 22 composite samples were collected. The concentration of cations and anions of the Langtang Valley were found in the order Ca2+ > K+ > Na+ > Mg2+ and , respectively. Significant seasonal variation in electrical conductivity (EC), turbidity, dissolved oxygen (DO), calcium (Ca), sodium (Na), magnesium (Mg), chloride (Cl), sulphate (SO4) and total phosphorus (TP-PO4) and altitudinal variation in EC, total dissolved solids (TDS), DO and Na was found out. The concentrations of the heavy metals (As, Al, Mn, Zn, Cd, Cr) were below the detection limit except Fe (0.5 to 18.1 mg/l), which was highly variable. Calcium carbonate weathering was found out to be the major source of dissolved ions in the region. The elemental ratios (Ca/Si and K/Na) were typical of glacial melt water and the low Na/Cl and K/Cl ratios indicated major contribution from atmospheric precipitation to the observed dissolved ions of melt waters. The study showed an increase in the concentration of cations as compared to previous studies, which could be attributed to increasing weathering rates due to temperature increase. Elevated concentration of NO3 and TP-PO4 compared to previous studies show the effect of human impact in the region. Differences in the melt water composition between the debris covered and clean type glacier was found out.
