Given the analysis of underground pressure, a stress calculation model of coal floor stress has been established based on a theory of elasticity. The model presents the law of stress distribution on the relatively fix...Given the analysis of underground pressure, a stress calculation model of coal floor stress has been established based on a theory of elasticity. The model presents the law of stress distribution on the relatively fixed position of the mining coal floor： the extent of stress variation in a fixed floor position decreases gradually along with depth, the decreasing rate of the vertical stress is clearly larger than that of the horizontal stress at a specific depth. The direction of the maximum principal stress changes gradually from a vertical direction to a horizontal direction with the advance of the working face. The deformation and permeability of the rock mass of the coal floor are obtained by contrasting the difference of the principal stress established from theoretical calculations with curves of stress-strain and permeability-strain from tests, which is an important mechanical basis for preventing water inrush from confined aauifers.展开更多
Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with dif...Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with different patterns of liver diseases and high risk populations in different parts of China. Genotypes of HCV in some isolates were further ana- lyzed, based on the data from our laboratory studies and some carefully selected published literatures. Results: The anti-HCV positive rates were 9.7% in patients with acute hepatitis, 13.3% in patients with chronic hepatitis, 18.3% in patients with hepatocel- lular carcinoma, 33.0% in patients with liver cirrho- sis, and 43.2% in patients with posttransfusional hepatitis (average, 16.2% in patients with liver di- seases). The anti-HCV positive rates in the high risk populations were 36.4% in leukemic patients, 43.0% in hemodialysis patients, 12.7% in blood do- nors, 64.1% in drug abusers, 13.1% in prostitutes, and 2.57% in naturally healthy people. At least 4 clades (clades 1, 2, 3 and 6) of HCV were found in China with different geographic and demographic distributions. Genotype 1b was the most widely dis- tributed genotype, and genotype 3 was mainly found in Yunnan Province, Southwest China. Conclusion: China has a high incidence of HCV in- fection. Our results will provide a strategic basis for diagnosis, treatment and possibly prophylaxis of he- patitis C virus diseases.展开更多
Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in...Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.展开更多
AIM:To report the incidence and potential risk factors of small-volume chylous ascites(SVCA)following laparoscopic radical gastrectomy(LAG).METHODS:A total of 1366 consecutive gastric cancer patients who underwent LAG...AIM:To report the incidence and potential risk factors of small-volume chylous ascites(SVCA)following laparoscopic radical gastrectomy(LAG).METHODS:A total of 1366 consecutive gastric cancer patients who underwent LAG from January 2008 to June 2011 were enrolled in this study.We analyzed the patients based on the presence or absence of SVCA.RESULTS:SVCA was detected in 57(4.17%)patients,as determined by the small-volume drainage(range,30-100 m L/24 h)of triglyceride-rich fluid.Both univariate and multivariate analyses revealed that the total number of resected lymph nodes(LNs),No.8 or No.9 LN metastasis and N stage were independent risk factors for SVCA following LAG(P<0.05).Regarding hospital stay,there was a significant difference between the groups with and without SVCA(P<0.001).The 3-year disease-free and overall survival rates of the patients with SVCA were 47.4%and 56.1%,respectively,which were similar to those of the patients without SVCA(P>0.05).CONCLUSION:SVCA following LAG developed significantly more frequently in the patients with≥32harvested LNs,≥3 metastatic LNs,or No.8 or No.9LN metastasis.SVCA,which was successfully treated with conservative management,was associated with a prolonged hospital stay but was not associated with the prognosis.展开更多
Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any ...Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any genetic relations are unknown yet.In this paper,a hydrocarbon gas-generation series,gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial,temporal and genetic relationships among natural natural gas hydrate,oil and gas.The subsequent results show that natural gas hydrate,oil and gas actually form a natural gas hydrate-oil-gas system.Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series,it is divided into four major sub-systems in the study area:(1)A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic;(2)a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic;(3)a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas;(4)a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system.This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical,and thus they will play an important role in the further exploration of natural gas hydrate,oil and gas,even other energy resources in the study area.展开更多
The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.U...The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.展开更多
1.Objectives As the discovery of gas hydrate in Qilian Mountain permafrost in 2008,the main controlling factors and distribution of gas hydrate are not clear.This restricts the further progress in gas hydrate survey i...1.Objectives As the discovery of gas hydrate in Qilian Mountain permafrost in 2008,the main controlling factors and distribution of gas hydrate are not clear.This restricts the further progress in gas hydrate survey in this area.Hence, China Geological Survey erected the project "Exploration of gas hydrate resources in the Qilian Mountain and its adjacent areas"continuously to better understand the gas hydrate accumulation in terms of greater gas hydrate discovery.展开更多
BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3...BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3(TIM3)plays a key immunomodulatory role and is linked to the prognosis of various cancers.However,the significance of TIM3 in upper GI tract tumors is still uncertain.AIM To investigate the prognostic value of TIM3 expression in upper GI tract tumors.METHODS A literature search was conducted on the PubMed,Embase,and Web of Science databases for relevant studies published until June 2023.After screening and quality assessment,studies that met the criteria were included in the metaanalysis.Statistical methods were used for the pooled analysis to assess the association of TIM3 expression in upper GI tract tumors with the prognosis and clinicopathological parameters.The results were reported with the hazard ratio(HR)and 95%confidence interval(CI).RESULTS Nine studies involving 2556 patients with upper GI tract cancer were included.High TIM3 expression was associated with a worse prognosis in upper GI tract cancer(HR:1.17,95%CI:1.01-1.36).Positive expression of TIM3 in gastric cancer was correlated with the T and N stage,but the difference was not statistically significant.However,TIM3 overexpression was significantly correlated with the TNM stage(odds ratio:1.21,95%CI:0.63-2.33;P<0.05).TIM3 expression showed no association with the other clinicopathological parameters.CONCLUSION High expression of TIM3 in the upper GI tract cancer is associated with a worse prognosis and advanced T or N stages,indicating its potential value as a prognostic biomarker.These findings may provide a basis for the personalized treatment of upper GI tract cancers.展开更多
Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering ...Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering pressure and substrate temperature on the crystalline nature,morphology,electrical and optical properties of the deposited thin films were analyzed by X-ray diffraction(XRD),atomic force microscopy(AFM),four-point resistivity test system and ultraviolet visible near-infrared(UV-Vis-NIR) spectroscopy,respectively.The results show that single(200)-oriented TiN thin films can be obtained at a wide range of substrate temperature from 200 to 600 ℃ with the grain size increasing from 35.9 to 64.5 nm.The resistivity of the product is as low as95 μΩ·cm,and the value of the optical reflectance is above68 % in the near-infrared(NIR) range of 760-1500 nm.展开更多
Analysis of phylogenetic and evolution in six species of Sorghum was based on internal transcribed spacer （ITS） sequences in nuclear ribosomal DNA. Results showed that the length of the ITS regions among the six spe...Analysis of phylogenetic and evolution in six species of Sorghum was based on internal transcribed spacer （ITS） sequences in nuclear ribosomal DNA. Results showed that the length of the ITS regions among the six species ranged from 588 to 589 bp and the contents of G＋C in ITS （ITS1 ＋5.8S＋ITS2） regions ranged from 60.27 to 61.05%; the length of ITS1 ranged from 207 to 208 bp and the contents of G ＋ C in the ITS 1 regions ranged from 53.91 to 61.54%. The length of the 5.8S rDNA and ITS2 regions in the six species was 164 and 217 bp respectively, and the contents of G ＋ C ranged from 56.10 to 58.54% in the 5.8S rDNA region and 66.36 to 67,28% in the ITS2 region. Among regions of ITS, ITS1, ITS2, and 5.8S, the best sequence for genetic relationship analysis in the six species was the ITS region. On the basis of the Jaccard coefficient and phylogentic tree, S. sp. was more related to S, propinguum than to other species. This was consistent with the fact that S. sp. is derived from S. propinguum. From the phylogenetic tree based on ITS1, S. halepense, silk sorghum and S. sudanense, are identical in the ITS 1 sequence, whereas the phylogenetic tree based one shows that S. sudanense has a closer genetic association with S. almum rather than with S. halepense and silk sorghum.展开更多
The Qinghai-Tibet Plateau(also referred to as the Plateau)is the largest area bearing alpine permafrost region in the world and thus is endowed with great formation conditions and prospecting potential of natural gas ...The Qinghai-Tibet Plateau(also referred to as the Plateau)is the largest area bearing alpine permafrost region in the world and thus is endowed with great formation conditions and prospecting potential of natural gas hydrates(NGH).Up to now,one NGH accumulation,two inferred NGH accumulations,and a series of NGH-related anomalous indicators have been discovered in the Plateau,with NGH resources predicted to be up to 8.88×10^(12) m^(3).The NGH in the Qinghai-Tibet Plateau have complex gas components and are dominated by deep thermogenic gas.They occur in the Permian-Jurassic strata and are subject to thin permafrost and sensitive to environment.Furthermore,they are distinctly different from the NGH in the high-latitude permafrost in the arctic regions and are more different from marine NGH.The formation of the NGH in the Plateau obviously couples with the uplift and permafrost evolution of the Plateau in spatial-temporal terms.The permafrost and NGH in the Qilian Mountains and the main body of the Qinghai-Tibet Plateau possibly formed during 2.0–1.28 Ma BP and about 0.8 Ma BP,respectively.Under the context of global warming,the permafrost in the Qinghai-Tibet Plateau is continually degrading,which will lead to the changes in the stability of NGH.Therefore,The NGH of the Qinghai-Tibet Plateau can not be ignored in the study of the global climate change and ecological environment.展开更多
Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) report...Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.展开更多
The kinetic behaviors of aggregation-fragmentation-annihilation processes of three n-species systems arestudied in this paper. Aggregation reaction occurs only between the same species but irreversible annihilation re...The kinetic behaviors of aggregation-fragmentation-annihilation processes of three n-species systems arestudied in this paper. Aggregation reaction occurs only between the same species but irreversible annihilation reactionoccurs between two different species, and meanwhile the fragmentation reaction coexists. Based on the mean-field theory,we investigate the rate equations of the processes and obtain the asymptotic descriptions of the cluster-mass distributionsfor the symmetrical cases. We find that the fragmentation reaction may lead to the complete breakdown of the standardscaling description for the cluster-mass distribution of each species contrast to the scaling behavior of aggregation-annihilation processes without fragmentation.In our joint annihilation model, we also observe that the kinetic behaviorsof distinct species are quite complicated for the case with different initial concentrations. The cluster-mass distributionof heavy species with the largest initial concentration possesses peculiar scaling properties, while that of light species hasnot scaling behavior.展开更多
A competition model of three species in exchange-driven aggregation growth is proposed. In the model, three distinct aggregates grow by exchange of monomers and in parallel, birth of species A is catalyzed by species ...A competition model of three species in exchange-driven aggregation growth is proposed. In the model, three distinct aggregates grow by exchange of monomers and in parallel, birth of species A is catalyzed by species B and death of species A is catalyzed by species C. The rates for both catalysis processes are proportional to kj^v and ky respectively, where ν（ω） is a parameter reflecting the dependence of the catalysis reaction rate of birth （death） on the catalyst aggregate＇s size. The kinetic evolution behaviors of the three species are investigated by the rate equation approach based on the mean-field theory： The form of the aggregate size distribution of A-species αk（t） is found to be dependent crucially on the two catalysis rate kernel parameters. The results show that （i） in case of ν ≤O, the form of ak （t） mainly depends on the competition between self-exchange of species A and species-C-catalyzed death of species A; （ii） in case of ν 〉 0, the form of αk（t） mainly depends on the competition between species-B-catalyzed birth of species A and species-C-catalyzed death of species A.展开更多
Accurate and effective detection of hydrogen peroxide(H_(2)O_(2))is of great significance in physiological functions as well as industrial applications.In this paper,the rod-like NiO-Co_(3)O_(4)nanomaterials were synt...Accurate and effective detection of hydrogen peroxide(H_(2)O_(2))is of great significance in physiological functions as well as industrial applications.In this paper,the rod-like NiO-Co_(3)O_(4)nanomaterials were synthesized by a simple hydrothermal method for electrochemical detection of H_(2)O_(2).The characterization results indicated that the nanomaterials possess high porosity and excellent conductivity,and displayed good electrocatalysis activity at the same time.Under alkaline conditions,the as-prepared nanomaterials can catalyze the reduction of H_(2)O_(2)and realize the electron transfer between H_(2)O_(2)and the electrode.The H_(2)O_(2)electrochemical sensor based on NiO-Co_(3)O_(4)nanomaterials exhibited a wide linear response(1-250 and 250-1200μmol/L),a low detection limit(0.1μmol/L)and a high sensitivity(5305.59μA/(mmol/L·cm^(2))(S/N=3)).In addition,the fabricated sensor showed high selectivity,good repeatability and high stability.The applications of the proposed sensor for H_(2)O_(2)detection in food samples were demonstrated and satisfactory results were obtained.展开更多
Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community.As the world’s third pole,the global warming amplifier,and the...Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community.As the world’s third pole,the global warming amplifier,and the starting region of China’s climate change,the Qinghai-Tibet Plateau is extremely sensitive to climate change.The permafrost on the Qinghai-Tibet Plateau is rich in natural gas hydrates(NGHs)resources.Under the background of global warming,whether the NGHs will be disassociated and enter the atmosphere as the air temperature rises has become a major concern of both the public and the scientific community.Given this,this study reviewed the trend of global warming and accordingly summarized the characteristics of the temperature increase in the Qinghai-Tibet Plateau.Based on this as well as the distribution characteristics of the NGHs in the permafrost on the Qinghai-Tibet Plateau,this study investigated the changes in the response of the NGHs to global warming,aiming to clarify the impacts of global warming on the NGHs in the permafrost of the plateau.A noticeable response to global warming has been observed in the Qinghai-Tibet Plateau.Over the past decades,the increase in the mean annual air temperature of the plateau was increasingly high and more recently.Specifically,the mean annual air temperature of the plateau changed at a rate of approximately 0.308-0.420℃/10a and increased by approximately 1.54-2.10℃in the past decades.Moreover,the annual mean ground temperature of the shallow permafrost on the plateau increased by approximately 1.155-1.575℃and the permafrost area decreased by approximately 0.34×10^(6)km^(2) from about 1.4×10^(6)km^(2) to 1.06×10^(6)km^(2) in the past decades.As indicated by simulated calculation results,the thickness of the NGH-bearing permafrost on the Qinghai-Tibet Plateau has decreased by 29-39 m in the past 50 years,with the equivalent of(1.69-2.27)×10^(10)-(1.12-1.51)×10^(12)m^(3) of methane(CH_(4))being released due to NGHs dissociation.It is predicted 展开更多
Opioid addiction is one of the top challenges for society, particularly in China. To fight it, the key is to reveal its underlying mechanisms. Among the strategies to overcome the mental damage caused by opioids, inve...Opioid addiction is one of the top challenges for society, particularly in China. To fight it, the key is to reveal its underlying mechanisms. Among the strategies to overcome the mental damage caused by opioids, investigating native anti-opioid peptides derived from mammalian （including human） brains is an important option because of safety concerns. In 1983, diazepam-binding inhibitor （DBI）, a 10-kDa peptide, was first derived from rat brains （Guidotti et al., 1983）. After repeated treatment with morphine, the DBI level is enhanced in rodent brains （Katsura et al., 1998; Shibasaki et al., 2006）.展开更多
Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subs...Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subsequent loss of neuronal function is a serious threat to human health One of several diseases.For patients with cerebral ischemia,often the lack of effective and extensive treatment.In addition,cerebral ischemia with morbidity,morbidity and mortality are characterized by high,so by the medical profession at home and abroad attention.As a traditional Chinese medicine,cordyceps sinensis(CS)is a complex of ergot fungus,which is parasitized on the larvae of the bat-moth family.The compound is composed of cordycepin,cordyceps polysaccharide,cordyceps sinensis peptides,ergosterol,mannitol,fatty acids and trace elements such as a variety of ingredients,with a wide range of pharmacological effects.Over the years,domestic and foreign scholars on the pharmacological effects of cordyceps sinensis were more comprehensive study of its prevention and treatment of cerebral ischemia is also deepening,found that cordyceps sinensis on cerebral ischemia with anti-inflammatory,reduce oxidative damage and neuronal ischemia damage,reduce neuronal apoptosis,improve memory cognition,reduce thrombosis,inhibit NO production,enhance mitochondrial energy supply,scavenging free radicals and other prevention and treatment.But no relevant review.In this paper,the domestic and foreign literatures on the prevention and treatment of cerebral ischemia by cordyceps sinensis were summarized,analyzed and summarized in order to provide useful information for the research and further development of cordyceps sinensis.展开更多
We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through selfex...We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through selfexchanges with the rate kernels Kl（k,j） = K1kj and K2（h,j） = K2kj, respectively. The actions of the population and asset aggregations on the aggregation evolution of resource aggregates are described by the population-catalyzed monomer death of resource aggregates and asset-catalyzed monomer birth of resource aggregates with the rate kerne/s J1（k,j）=J1k and J2（k,j） = J2k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I1 （k,i,j） = I1ki^μjη, and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel /2（k, i, j） = I2ki^νj^η. The kinetic behaviors of species A, B, and C are investigated by means of the mean-field rate equation approach. The effects of the population-catalyzed death and asset-catalyzed birth on the evolution of resource aggregates based on the self-exchanges of population and asset appear in effective forms. The coefficients of the effective population-catalyzed death and the asset-catalyzed birth are expressed as J1e = J1/K1 and J2e= J2/K2, respectively. The aggregate size distribution of C species is found to be crucially dominated by the competition between the effective death and the effective birth. It satisfies the conventional scaling form, generalized scaling form, and modified scaling form in the cases of J1e〈J2e, J1e=J2e, and J1e〉J2e, respectively. Meanwhile, we also find the aggregate size distributions of populations and assets both fall into two distinct categories for different parameters μ,ν, and η： （i） When μ=ν=η=0 and μ=ν=η=1, the population and asset aggregates obey the generalized scaling forms; and （ii） When μ=ν=1,η=0, and μ=ν=η=1, the population and asset aggre展开更多
文摘Given the analysis of underground pressure, a stress calculation model of coal floor stress has been established based on a theory of elasticity. The model presents the law of stress distribution on the relatively fixed position of the mining coal floor： the extent of stress variation in a fixed floor position decreases gradually along with depth, the decreasing rate of the vertical stress is clearly larger than that of the horizontal stress at a specific depth. The direction of the maximum principal stress changes gradually from a vertical direction to a horizontal direction with the advance of the working face. The deformation and permeability of the rock mass of the coal floor are obtained by contrasting the difference of the principal stress established from theoretical calculations with curves of stress-strain and permeability-strain from tests, which is an important mechanical basis for preventing water inrush from confined aauifers.
文摘Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with different patterns of liver diseases and high risk populations in different parts of China. Genotypes of HCV in some isolates were further ana- lyzed, based on the data from our laboratory studies and some carefully selected published literatures. Results: The anti-HCV positive rates were 9.7% in patients with acute hepatitis, 13.3% in patients with chronic hepatitis, 18.3% in patients with hepatocel- lular carcinoma, 33.0% in patients with liver cirrho- sis, and 43.2% in patients with posttransfusional hepatitis (average, 16.2% in patients with liver di- seases). The anti-HCV positive rates in the high risk populations were 36.4% in leukemic patients, 43.0% in hemodialysis patients, 12.7% in blood do- nors, 64.1% in drug abusers, 13.1% in prostitutes, and 2.57% in naturally healthy people. At least 4 clades (clades 1, 2, 3 and 6) of HCV were found in China with different geographic and demographic distributions. Genotype 1b was the most widely dis- tributed genotype, and genotype 3 was mainly found in Yunnan Province, Southwest China. Conclusion: China has a high incidence of HCV in- fection. Our results will provide a strategic basis for diagnosis, treatment and possibly prophylaxis of he- patitis C virus diseases.
基金supported by the National Natural Science Foundation of China,No.81460208the Ningxia Natural Science Foundation of China,No.NZ13163
文摘Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.
基金Supported by Grants from National Key Clinical Specialty Discipline Construction Program of China,No.[2012]649
文摘AIM:To report the incidence and potential risk factors of small-volume chylous ascites(SVCA)following laparoscopic radical gastrectomy(LAG).METHODS:A total of 1366 consecutive gastric cancer patients who underwent LAG from January 2008 to June 2011 were enrolled in this study.We analyzed the patients based on the presence or absence of SVCA.RESULTS:SVCA was detected in 57(4.17%)patients,as determined by the small-volume drainage(range,30-100 m L/24 h)of triglyceride-rich fluid.Both univariate and multivariate analyses revealed that the total number of resected lymph nodes(LNs),No.8 or No.9 LN metastasis and N stage were independent risk factors for SVCA following LAG(P<0.05).Regarding hospital stay,there was a significant difference between the groups with and without SVCA(P<0.001).The 3-year disease-free and overall survival rates of the patients with SVCA were 47.4%and 56.1%,respectively,which were similar to those of the patients without SVCA(P>0.05).CONCLUSION:SVCA following LAG developed significantly more frequently in the patients with≥32harvested LNs,≥3 metastatic LNs,or No.8 or No.9LN metastasis.SVCA,which was successfully treated with conservative management,was associated with a prolonged hospital stay but was not associated with the prognosis.
基金This work was supported by the projects of China Geological Survey(DD20160223,DD20190102).
文摘Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any genetic relations are unknown yet.In this paper,a hydrocarbon gas-generation series,gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial,temporal and genetic relationships among natural natural gas hydrate,oil and gas.The subsequent results show that natural gas hydrate,oil and gas actually form a natural gas hydrate-oil-gas system.Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series,it is divided into four major sub-systems in the study area:(1)A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic;(2)a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic;(3)a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas;(4)a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system.This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical,and thus they will play an important role in the further exploration of natural gas hydrate,oil and gas,even other energy resources in the study area.
基金the financial support of the National Natural Science Foundation of China(42176212,41976074 and 41302034)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(2021QNLM020002)the Marine Geological Survey Program(DD20221704)。
文摘The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.
文摘1.Objectives As the discovery of gas hydrate in Qilian Mountain permafrost in 2008,the main controlling factors and distribution of gas hydrate are not clear.This restricts the further progress in gas hydrate survey in this area.Hence, China Geological Survey erected the project "Exploration of gas hydrate resources in the Qilian Mountain and its adjacent areas"continuously to better understand the gas hydrate accumulation in terms of greater gas hydrate discovery.
基金Supported by the Science and Technology Research Project of Colleges and Universities of Hebei Province,No.QN2020234the Precision Medicine Joint Cultivation Fund Project of Natural Science Foundation of Hebei Province,No.H2021402007+1 种基金the Clinical Medicine Talent Cultivation Project of Health Commission of Hebei Province,No.2020the Medical Science Research Project of Health Commission of Hebei Province,No.20211392.
文摘BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3(TIM3)plays a key immunomodulatory role and is linked to the prognosis of various cancers.However,the significance of TIM3 in upper GI tract tumors is still uncertain.AIM To investigate the prognostic value of TIM3 expression in upper GI tract tumors.METHODS A literature search was conducted on the PubMed,Embase,and Web of Science databases for relevant studies published until June 2023.After screening and quality assessment,studies that met the criteria were included in the metaanalysis.Statistical methods were used for the pooled analysis to assess the association of TIM3 expression in upper GI tract tumors with the prognosis and clinicopathological parameters.The results were reported with the hazard ratio(HR)and 95%confidence interval(CI).RESULTS Nine studies involving 2556 patients with upper GI tract cancer were included.High TIM3 expression was associated with a worse prognosis in upper GI tract cancer(HR:1.17,95%CI:1.01-1.36).Positive expression of TIM3 in gastric cancer was correlated with the T and N stage,but the difference was not statistically significant.However,TIM3 overexpression was significantly correlated with the TNM stage(odds ratio:1.21,95%CI:0.63-2.33;P<0.05).TIM3 expression showed no association with the other clinicopathological parameters.CONCLUSION High expression of TIM3 in the upper GI tract cancer is associated with a worse prognosis and advanced T or N stages,indicating its potential value as a prognostic biomarker.These findings may provide a basis for the personalized treatment of upper GI tract cancers.
基金the National Natural Science Foundation of China and External science and technology cooperation program of Jiangxi Province(Nos.11364032 and 20151BDH80030)。
文摘Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering pressure and substrate temperature on the crystalline nature,morphology,electrical and optical properties of the deposited thin films were analyzed by X-ray diffraction(XRD),atomic force microscopy(AFM),four-point resistivity test system and ultraviolet visible near-infrared(UV-Vis-NIR) spectroscopy,respectively.The results show that single(200)-oriented TiN thin films can be obtained at a wide range of substrate temperature from 200 to 600 ℃ with the grain size increasing from 35.9 to 64.5 nm.The resistivity of the product is as low as95 μΩ·cm,and the value of the optical reflectance is above68 % in the near-infrared(NIR) range of 760-1500 nm.
文摘Analysis of phylogenetic and evolution in six species of Sorghum was based on internal transcribed spacer （ITS） sequences in nuclear ribosomal DNA. Results showed that the length of the ITS regions among the six species ranged from 588 to 589 bp and the contents of G＋C in ITS （ITS1 ＋5.8S＋ITS2） regions ranged from 60.27 to 61.05%; the length of ITS1 ranged from 207 to 208 bp and the contents of G ＋ C in the ITS 1 regions ranged from 53.91 to 61.54%. The length of the 5.8S rDNA and ITS2 regions in the six species was 164 and 217 bp respectively, and the contents of G ＋ C ranged from 56.10 to 58.54% in the 5.8S rDNA region and 66.36 to 67,28% in the ITS2 region. Among regions of ITS, ITS1, ITS2, and 5.8S, the best sequence for genetic relationship analysis in the six species was the ITS region. On the basis of the Jaccard coefficient and phylogentic tree, S. sp. was more related to S, propinguum than to other species. This was consistent with the fact that S. sp. is derived from S. propinguum. From the phylogenetic tree based on ITS1, S. halepense, silk sorghum and S. sudanense, are identical in the ITS 1 sequence, whereas the phylogenetic tree based one shows that S. sudanense has a closer genetic association with S. almum rather than with S. halepense and silk sorghum.
基金the China Geological Survey entitled Comprehensive Survey of Terrestrial NGH Resources(DD20190102).
文摘The Qinghai-Tibet Plateau(also referred to as the Plateau)is the largest area bearing alpine permafrost region in the world and thus is endowed with great formation conditions and prospecting potential of natural gas hydrates(NGH).Up to now,one NGH accumulation,two inferred NGH accumulations,and a series of NGH-related anomalous indicators have been discovered in the Plateau,with NGH resources predicted to be up to 8.88×10^(12) m^(3).The NGH in the Qinghai-Tibet Plateau have complex gas components and are dominated by deep thermogenic gas.They occur in the Permian-Jurassic strata and are subject to thin permafrost and sensitive to environment.Furthermore,they are distinctly different from the NGH in the high-latitude permafrost in the arctic regions and are more different from marine NGH.The formation of the NGH in the Plateau obviously couples with the uplift and permafrost evolution of the Plateau in spatial-temporal terms.The permafrost and NGH in the Qilian Mountains and the main body of the Qinghai-Tibet Plateau possibly formed during 2.0–1.28 Ma BP and about 0.8 Ma BP,respectively.Under the context of global warming,the permafrost in the Qinghai-Tibet Plateau is continually degrading,which will lead to the changes in the stability of NGH.Therefore,The NGH of the Qinghai-Tibet Plateau can not be ignored in the study of the global climate change and ecological environment.
基金This study was supported by research grants from ICGEB Collaborative Research Program (CRP/CHN96-05) and from China Yunnan Provincial Science & Technology Commission International Collaborative Research Program (97C009).
文摘Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.
文摘The kinetic behaviors of aggregation-fragmentation-annihilation processes of three n-species systems arestudied in this paper. Aggregation reaction occurs only between the same species but irreversible annihilation reactionoccurs between two different species, and meanwhile the fragmentation reaction coexists. Based on the mean-field theory,we investigate the rate equations of the processes and obtain the asymptotic descriptions of the cluster-mass distributionsfor the symmetrical cases. We find that the fragmentation reaction may lead to the complete breakdown of the standardscaling description for the cluster-mass distribution of each species contrast to the scaling behavior of aggregation-annihilation processes without fragmentation.In our joint annihilation model, we also observe that the kinetic behaviorsof distinct species are quite complicated for the case with different initial concentrations. The cluster-mass distributionof heavy species with the largest initial concentration possesses peculiar scaling properties, while that of light species hasnot scaling behavior.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10275048,10305009,and 10875086by the Zhejiang Provincial Natural Science Foundation of China under Grant No.102067
文摘A competition model of three species in exchange-driven aggregation growth is proposed. In the model, three distinct aggregates grow by exchange of monomers and in parallel, birth of species A is catalyzed by species B and death of species A is catalyzed by species C. The rates for both catalysis processes are proportional to kj^v and ky respectively, where ν（ω） is a parameter reflecting the dependence of the catalysis reaction rate of birth （death） on the catalyst aggregate＇s size. The kinetic evolution behaviors of the three species are investigated by the rate equation approach based on the mean-field theory： The form of the aggregate size distribution of A-species αk（t） is found to be dependent crucially on the two catalysis rate kernel parameters. The results show that （i） in case of ν ≤O, the form of ak （t） mainly depends on the competition between self-exchange of species A and species-C-catalyzed death of species A; （ii） in case of ν 〉 0, the form of αk（t） mainly depends on the competition between species-B-catalyzed birth of species A and species-C-catalyzed death of species A.
基金provided by Natural science fund for colleges and universities in Jiangsu Province (19KJB550002)State Key Laboratory of Analytical Chemistry for Life Science (SKLACLS2001),Nanjing University
文摘Accurate and effective detection of hydrogen peroxide(H_(2)O_(2))is of great significance in physiological functions as well as industrial applications.In this paper,the rod-like NiO-Co_(3)O_(4)nanomaterials were synthesized by a simple hydrothermal method for electrochemical detection of H_(2)O_(2).The characterization results indicated that the nanomaterials possess high porosity and excellent conductivity,and displayed good electrocatalysis activity at the same time.Under alkaline conditions,the as-prepared nanomaterials can catalyze the reduction of H_(2)O_(2)and realize the electron transfer between H_(2)O_(2)and the electrode.The H_(2)O_(2)electrochemical sensor based on NiO-Co_(3)O_(4)nanomaterials exhibited a wide linear response(1-250 and 250-1200μmol/L),a low detection limit(0.1μmol/L)and a high sensitivity(5305.59μA/(mmol/L·cm^(2))(S/N=3)).In addition,the fabricated sensor showed high selectivity,good repeatability and high stability.The applications of the proposed sensor for H_(2)O_(2)detection in food samples were demonstrated and satisfactory results were obtained.
基金supported by the projects of the China Geological Survey(DD20190102,DD20221857).
文摘Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community.As the world’s third pole,the global warming amplifier,and the starting region of China’s climate change,the Qinghai-Tibet Plateau is extremely sensitive to climate change.The permafrost on the Qinghai-Tibet Plateau is rich in natural gas hydrates(NGHs)resources.Under the background of global warming,whether the NGHs will be disassociated and enter the atmosphere as the air temperature rises has become a major concern of both the public and the scientific community.Given this,this study reviewed the trend of global warming and accordingly summarized the characteristics of the temperature increase in the Qinghai-Tibet Plateau.Based on this as well as the distribution characteristics of the NGHs in the permafrost on the Qinghai-Tibet Plateau,this study investigated the changes in the response of the NGHs to global warming,aiming to clarify the impacts of global warming on the NGHs in the permafrost of the plateau.A noticeable response to global warming has been observed in the Qinghai-Tibet Plateau.Over the past decades,the increase in the mean annual air temperature of the plateau was increasingly high and more recently.Specifically,the mean annual air temperature of the plateau changed at a rate of approximately 0.308-0.420℃/10a and increased by approximately 1.54-2.10℃in the past decades.Moreover,the annual mean ground temperature of the shallow permafrost on the plateau increased by approximately 1.155-1.575℃and the permafrost area decreased by approximately 0.34×10^(6)km^(2) from about 1.4×10^(6)km^(2) to 1.06×10^(6)km^(2) in the past decades.As indicated by simulated calculation results,the thickness of the NGH-bearing permafrost on the Qinghai-Tibet Plateau has decreased by 29-39 m in the past 50 years,with the equivalent of(1.69-2.27)×10^(10)-(1.12-1.51)×10^(12)m^(3) of methane(CH_(4))being released due to NGHs dissociation.It is predicted
基金ACKNOWLEDGEMENTS We thank Dr. lain C Bruce for helpful comments on the manuscript. 77 and ZL were partially supported by grants from the National Basic Research Program （973 Program） （No. 2012CB518006）, and the National Natural Science Foundation of China （Grant Nos. 31228010, 31171026, 31100597, 31327901, 31221002, 31330024, 31400708, 31670843, 31521062, and SQ2011SF11B01041）. Yu-Zhen Chen, Xiao-Cun Li, Zhen-Quan Guo, Li Zhou, Zhuan Zhou, Song-vve no conflict of interest. This article does not contain any studies with human subjects performed by the any of the authors. All institutional and national guidelines for the care and use of laboratory animals were followed.
文摘Opioid addiction is one of the top challenges for society, particularly in China. To fight it, the key is to reveal its underlying mechanisms. Among the strategies to overcome the mental damage caused by opioids, investigating native anti-opioid peptides derived from mammalian （including human） brains is an important option because of safety concerns. In 1983, diazepam-binding inhibitor （DBI）, a 10-kDa peptide, was first derived from rat brains （Guidotti et al., 1983）. After repeated treatment with morphine, the DBI level is enhanced in rodent brains （Katsura et al., 1998; Shibasaki et al., 2006）.
基金supported by National Natural Science Foundation of China(81403319,81603453)Beijing Young Backbone Individual Project(2014000020124G114)
文摘Cerebral ischemia is due to cerebral blood supply disorders caused by ischemia and hypoxia resulting in localized ischemic brain necrosis or brain softening of the disease,leading to irreversible brain damage and subsequent loss of neuronal function is a serious threat to human health One of several diseases.For patients with cerebral ischemia,often the lack of effective and extensive treatment.In addition,cerebral ischemia with morbidity,morbidity and mortality are characterized by high,so by the medical profession at home and abroad attention.As a traditional Chinese medicine,cordyceps sinensis(CS)is a complex of ergot fungus,which is parasitized on the larvae of the bat-moth family.The compound is composed of cordycepin,cordyceps polysaccharide,cordyceps sinensis peptides,ergosterol,mannitol,fatty acids and trace elements such as a variety of ingredients,with a wide range of pharmacological effects.Over the years,domestic and foreign scholars on the pharmacological effects of cordyceps sinensis were more comprehensive study of its prevention and treatment of cerebral ischemia is also deepening,found that cordyceps sinensis on cerebral ischemia with anti-inflammatory,reduce oxidative damage and neuronal ischemia damage,reduce neuronal apoptosis,improve memory cognition,reduce thrombosis,inhibit NO production,enhance mitochondrial energy supply,scavenging free radicals and other prevention and treatment.But no relevant review.In this paper,the domestic and foreign literatures on the prevention and treatment of cerebral ischemia by cordyceps sinensis were summarized,analyzed and summarized in order to provide useful information for the research and further development of cordyceps sinensis.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10775104, 10275048, and 10305009the Zhejiang Provincial Natural Science Foundation of China under Grant No. 102067
文摘We propose a solvable aggregation model to mimic the evolution of population A, asset B, and the quantifiable resource C in a society. In this system, the population and asset aggregates themselves grow through selfexchanges with the rate kernels Kl（k,j） = K1kj and K2（h,j） = K2kj, respectively. The actions of the population and asset aggregations on the aggregation evolution of resource aggregates are described by the population-catalyzed monomer death of resource aggregates and asset-catalyzed monomer birth of resource aggregates with the rate kerne/s J1（k,j）=J1k and J2（k,j） = J2k, respectively. Meanwhile, the asset and resource aggregates conjunctly catalyze the monomer birth of population aggregates with the rate kernel I1 （k,i,j） = I1ki^μjη, and population and resource aggregates conjunctly catalyze the monomer birth of asset aggregates with the rate kernel /2（k, i, j） = I2ki^νj^η. The kinetic behaviors of species A, B, and C are investigated by means of the mean-field rate equation approach. The effects of the population-catalyzed death and asset-catalyzed birth on the evolution of resource aggregates based on the self-exchanges of population and asset appear in effective forms. The coefficients of the effective population-catalyzed death and the asset-catalyzed birth are expressed as J1e = J1/K1 and J2e= J2/K2, respectively. The aggregate size distribution of C species is found to be crucially dominated by the competition between the effective death and the effective birth. It satisfies the conventional scaling form, generalized scaling form, and modified scaling form in the cases of J1e〈J2e, J1e=J2e, and J1e〉J2e, respectively. Meanwhile, we also find the aggregate size distributions of populations and assets both fall into two distinct categories for different parameters μ,ν, and η： （i） When μ=ν=η=0 and μ=ν=η=1, the population and asset aggregates obey the generalized scaling forms; and （ii） When μ=ν=1,η=0, and μ=ν=η=1, the population and asset aggre
