Application of biochar to soils changes soil physicochemical properties and stimulates the activities of soil microorganisms that influence soil quality and plant performance.Studying the response of soil microbial co...Application of biochar to soils changes soil physicochemical properties and stimulates the activities of soil microorganisms that influence soil quality and plant performance.Studying the response of soil microbial communities to biochar amendments is important for better understanding interactions of biochar with soil,as well as plants.However,the effect of biochar on soil microorganisms has received less attention than its influences on soil physicochemical properties.In this review,the following key questions are discussed:(i)how does biochar affect soil microbial activities,in particular soil carbon(C)mineralization,nutrient cycling,and enzyme activities?(ii)how do microorganisms respond to biochar amendment in contaminated soils?and(iii)what is the role of biochar as a growth promoter for soil microorganisms?Many studies have demonstrated that biochar-soil application enhances the soil microbial biomass with substantial changes in microbial community composition.Biochar amendment changes microbial habitats,directly or indirectly affects microbial metabolic activities,and modifies the soil microbial community in terms of their diversity and abundance.However,chemical properties of biochar,(especially pH and nutrient content),and physical properties such as pore size,pore volume,and specific surface area play significant roles in determining the efficacy of biochar on microbial performance as biochar provides suitable habitats for microorgan-isms.The mode of action of biochar leading to stimulation of microbial activities is complex and is influenced by the nature of biochar as well as soil conditions.展开更多
The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the ...The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster mechanisms of rock media.展开更多
Mitophagy is activated by a number of stimuli, including hypoxia, energy stress, and increased oxidative phosphorylation activity. Mitophagy is associated with oxidative stress conditions and central neurodegenerative...Mitophagy is activated by a number of stimuli, including hypoxia, energy stress, and increased oxidative phosphorylation activity. Mitophagy is associated with oxidative stress conditions and central neurodegenerative diseases. Proper regulation of mitophagy is crucial for maintaining homeostasis; conversely, inadequate removal of mitochondria through mitophagy leads to the generation of oxidative species, including reactive oxygen species and reactive nitrogen species, resulting in various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. These diseases are most prevalent in older adults whose bodies fail to maintain proper mitophagic functions to combat oxidative species. As mitophagy is essential for normal body function, by targeting mitophagic pathways we can improve these disease conditions. The search for effective remedies to treat these disease conditions is an ongoing process, which is why more studies are needed. Additionally, more relevant studies could help establish therapeutic conditions, which are currently in high demand. In this review, we discuss how mitophagy plays a significant role in homeostasis and how its dysregulation causes neurodegeneration. We also discuss how combating oxidative species and targeting mitophagy can help treat these neurodegenerative diseases.展开更多
Biochar,an environmentally friendly soil conditioner,is produced using several thermochemical processes.It has unique characteristics like high surface area,porosity,and surface charges.This paper reviews the fertiliz...Biochar,an environmentally friendly soil conditioner,is produced using several thermochemical processes.It has unique characteristics like high surface area,porosity,and surface charges.This paper reviews the fertilizer value of biochar,and its effects on soil properties,and nutrient use efficiency of crops.Biochar serves as an important source of plant nutrients,especially nitrogen in biochar produced from manures and wastes at low temperature(≤400℃).The phosphorus,potassium,and other nutrient contents are higher in manure/waste biochars than those in crop residues and woody biochars.The nutrient contents and pH of biochar are positively correlated with pyrolysis temperature,except for nitrogen content.Biochar improves the nutrient retention capacity of soil,which depends on porosity and surface charge of biochar.Biochar increases nitrogen retention in soil by reducing leaching and gaseous loss,and also increases phosphorus availability by decreasing the leaching process in soil.However,for potassium and other nutrients,biochar shows inconsistent(positive and negative)impacts on soil.After addition of biochar,porosity,aggregate stability,and amount of water held in soil increase and bulk density decreases.Mostly,biochar increases soil pH and,thus,influences nutrient availability for plants.Biochar also alters soil biological properties by increasing microbial populations,enzyme activity,soil respiration,and microbial biomass.Finally,nutrient use efficiency and nutrient uptake improve with the application of biochar to soil.Thus,biochar can be a potential nutrient reservoir for plants and a good amendment to improve soil properties.展开更多
A mobile molecular Doppler wind lidar at an eye-safe wavelength of 355 nm based on double-edge technique is being built in Hefei （China） for wind measurement from 10-to 40-km altitude. The structure of this lidar sy...A mobile molecular Doppler wind lidar at an eye-safe wavelength of 355 nm based on double-edge technique is being built in Hefei （China） for wind measurement from 10-to 40-km altitude. The structure of this lidar system is described. A triple Fabry-Perot etalon is employed as a frequency discriminator whose parameters are optimized. The receiver system is designed to achieve compactness and stability by putting in a standard 19-inch socket bench. Simulation results show that within the wind speed dynamic range of ±100 m/s, the horizontal wind errors due to noise are less than 1 m/s bdow 20-km altitude for 100-m vertical resolution, and less than 5.5 m/s from 20 km up to 40 km for 500-m vertical resolution with 400-mJ laser energy, 30-min temporal resolution, and a 45-cm aperture telescooe.展开更多
AIM:To determine the utility of endoscopic ultrasoundguided biliary drainage(EUS-BD)with a fully covered self-expandable metal stent for managing malignant biliary stricture. METHODS:We collected data from 13 patients...AIM:To determine the utility of endoscopic ultrasoundguided biliary drainage(EUS-BD)with a fully covered self-expandable metal stent for managing malignant biliary stricture. METHODS:We collected data from 13 patients who presented with malignant biliary obstruction and underwent EUS-BD with a nitinol fully covered selfexpandable metal stent when endoscopic retrograde cholangiopancreatography(ERCP)fails.EUS-guided choledochoduodenostomy(EUS-CD)and EUS-guided hepaticogastrostomy(EUS-HG)was performed in 9 patients and 4 patients,respectively. RESULTS:The technical and functional success rate was 92.3%(12/13)and 91.7%(11/12),respectively. Using an intrahepatic approach(EUS-HG,n=4),there was mild peritonitis(n=1)and migration of the metal stent to the stomach(n=1).With an extrahepatic approach(EUS-CD,n=10),there was pneumoperitoneum(n=2),migration(n=2),and mild peritonitis (n=1).All patients were managed conservatively with antibiotics.During follow-up(range,1-12 mo),there was re-intervention(4/13 cases,30.7%)necessitated by stent migration(n=2)and stent occlusion(n=2). CONCLUSION:EUS-BD with a nitinol fully covered self-expandable metal stent may be a feasible and effective treatment option in patients with malignant biliary obstruction when ERCP fails.展开更多
AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients w...AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients who had been admitted to the Division of Gastroenterology with gastrointestinal symptoms were enrolled from March to April 2005. Of those who had been diagnosed with clonorchiasis, epidemiology and correlation between infection and hepatobiliary diseases were surveyed by questionnaire. RESULTS： Of 3080 patients with gastrointestinal diseases, 396 （12.9%） had clonorchiasis and 1140 patients （37.2%） had a history of eating raw freshwater fish. Of those with a history of raw freshwater fish ingestion, 238 （20.9%） patients had clonorchiasis. Cholangiocarcinoma was more prevalent in C. sinensis-infected patients than nonnfected patients [34/396 （8.6%） vs 145/2684 （5.4%）, P = 0.015]. Cholangiocarcinoma and clonorchiasis showed statistically significant positive cross-relation （P = 0.008）. Choledocholithiasis, cholecystolithiasis, cholangitis, hepatocellular carcinoma, and biliary pancreatitis did not correlate with clonorchiasis. CONCLUSION： Infection rate of clonorchiasis was still high in patients with gastrointestinal diseases in Korea, and has not decreased very much during the last two decades. Cholangiocarcinoma was related to clonorchiasis, which suggested an etiological role for the parasite.展开更多
AIM: To investigate treatment outcome of Helicobacter pylori (H.pylori )-negative low-grade gastric mucosaassociated lymphoid tissue (MALT) lymphoma.METHODS: In this study,we retrospectively reviewed the clinical outc...AIM: To investigate treatment outcome of Helicobacter pylori (H.pylori )-negative low-grade gastric mucosaassociated lymphoid tissue (MALT) lymphoma.METHODS: In this study,we retrospectively reviewed the clinical outcome and clinicopathologic factors of stage Ⅰ E H.pylori -negative low-grade gastric MALT lymphoma cases from August 1998 to June 2009.RESULTS: A total of eleven patients with H.pylori -negative low-grade gastric MALT lymphoma were enrolled in the study and received anti-H.pylori eradication treatment and/or radiotherapy or excisional therapy.Complete remission (CR) of gastric MALT lymphoma was achieved in all patients.The time to CR was 1-66 mo (median,1 mo).CONCLUSION: Eradication therapy may be offered as an initial treatment option even in cases of localized H.pylori -negative gastric MALT lymphoma.展开更多
AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma ...AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expre展开更多
AIM:To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS:A total of 55 pati...AIM:To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS:A total of 55 patients with MALTOMA from May 1992 to August 2002 were retrospectively reviewed. RESULTS:Complete remission was obtained in 24 (82.8%) of 29 patients treated with anti Helicobacter pylori (Hpylori) regimen only.The duration to reach complete remission was 12 months (85 percentile,2-33 months).Five patients showed complete remission with radiation therapy (26-86 months).Two of them were Hpyloritreatment failure cases. CONCLUSION:Hpylorieradication is an effective primary treatment option for low grade MALTOMA and radiation therapy could be considered in patients with no evidence of Hpyloriinfection or who do not respond to Hpylorieradication therapy 12 months after successful eradication.展开更多
AIM To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus(DM).METHODS Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cance...AIM To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus(DM).METHODS Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cancer. H&E stain and Masson's Trichrome stain were performed to assess the degree of fibrosis. Immunohistochemical staining using various antibodies was also performed [antibodies against protein gene product 9.5(PGP9.5), neuronal nitric oxide synthase(n NOS), vasoactive intestinal peptide(VIP), neurokinin-1(NK1) receptor, c-Kit, and platelet-derived growth factor receptor-alpha,(PDGFRα)]. Immunofluorescent staining and evaluation with confocal microscopy were also conducted.RESULTS Twenty-six controls and 35 diabetic patients(21 shortduration patients and 14 long-duration patients) were included. There were no significant differences in basic demographics between the two groups except in mean body mass index(BMI)(higher in the DM group). Proportions of moderate-to-severe intercellular fibrosis in the muscle layer were significantly higher in the DM group than in the control group(P < 0.01). On immunohistochemical staining, c-Kit- and PDGFRα-positive immunoreactivity were significantly decreased in the DM group compared with the control group(P < 0.05). There were no statistically significant differences in PGP9.5, n NOS, VIP, and neurokinin 1 expression. On immunofluorescent staining, cellularity of interstitial cells of Cajal(ICC) was observed to decrease with increasing duration of DM.CONCLUSION Our study suggests that increased intercellular fibrosis, loss of ICC, and loss of fibroblast-like cells are found in the smooth muscle of DM patients. These abnormalities may contribute to changes in gastric motor activity in patients with DM.展开更多
Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(...Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(TKIs),sorafenib and lenvatinib,and to identify a novel therapeutic target for overcoming TKI resistance in hepatocellular carcinoma(HCC).Methods:We performed a systematic integrative analysis of publicly available gene expression datasets and whole-transcriptome sequencing data from 9 pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues,respectively,to identify key molecules that might induce resistance to TKIs.We then performed in vitro and in vivo experiments to validate selected targets and related mechanisms.The associations of plasma secreted phosphoprotein 1(SPP1)expression levels before sorafenib/lenvatinib treatment with progression-free survival(PFS)and overall survival(OS)of 54 patients with advanced HCC were evaluated using Kaplan-Meier and Cox regression analysis.Results:Bioinformatic analysis identified CAF-derived SPP1 as a candidate molecule driving TKI resistance.SPP1 inhibitors reversed CAF-induced TKI resistance in vitro and in vivo.CAF-derived SPP1 activated rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)through the integrin-protein kinase C-alpha(PKCα)signaling pathway and promoted epithelial-to-mesenchymal transition(EMT).A high plasma SPP1 level before TKI treatment was identified as an independent predictor of poor PFS(P=0.026)and OS(P=0.047)in patients with advanced HCC after TKI treatment.Conclusions:CAF-derived SPP1 enhances TKI resistance in HCC via bypass activation of oncogenic signals and EMT promotion.Its inhibition represents a promising therapeutic strategy against TKI resistance inHCC.Moreover,plasma SPP1 level before TKI treatment represents a potential biomarker for treatment response prediction.展开更多
AIM To investigate the effect of Helicobacter pylori(H. pylori) status test and H. pylori eradication on the occurrence of metachronous gastric cancer(MGC) after endoscopic submucosal dissection(ESD) of early gastric ...AIM To investigate the effect of Helicobacter pylori(H. pylori) status test and H. pylori eradication on the occurrence of metachronous gastric cancer(MGC) after endoscopic submucosal dissection(ESD) of early gastric cancer(EGC) and risk factors of MGC. METHODS The authors retrospectively reviewed the medical records of 433 patients(441 lesions) who underwent ESD for EGC from January 2005 to January 2015 in Yeungnam University Hospital. Patients were categorized into two groups; the H. pylori tested group(n = 257) and the H. pylori non-tested group(n = 176) based on performance of H. pylori status test after ESD of EGC. The H. pylori tested group was further categorized into three subgroups based on H. pylori status; the H. pylori-eradicated subgroup(n = 120), the H. pylori-persistent subgroup(n = 42), and the H. pylori-negative subgroup(n = 95). Incidences of MGC and risk factors of MGC were identified.RESULTS Median follow-up duration after ESD was 30.00 mo(range, 6-107 mo). Total 15 patients developed MGC during follow-up. MGC developed in 11 patients of the H. pylori tested group(7 in the H. pylori-negative subgroup, 3 in the H. pylori-eradicated subgroup, and 1 in the H. pylori-persistent subgroup) and 4 patients of the H. pylori non-tested group(P > 0.05). The risk factors of MGC were endoscopic mucosal atrophy in the H. pylori tested group and intestinal metaplasia in all patients. CONCLUSION H. pylori eradication and H. pylori status test seems to have no preventive effect on the development of MGC after ESD for EGC. The risk factors of MGC development were endoscopic mucosal atrophy in the H. pylori tested group alone and intestinal metaplasia in all patients.展开更多
Ischemic colitis is the most common form of intestinal ischemia.It is a condition that is commonly seen in the elderly and among individuals with risk factors for ischemia.Common predisposing conditions for ischemic c...Ischemic colitis is the most common form of intestinal ischemia.It is a condition that is commonly seen in the elderly and among individuals with risk factors for ischemia.Common predisposing conditions for ischemic colitis are major vascular occlusion,small vessel disorder,shock,some medications,colonic obstructions and hematologic disorders.Ischemic colitis following colonoscopy is rare.Here,we report two cases of ischemic colitis after a routine screening colonoscopy in patients without risk factors for ischemia.展开更多
Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impa...Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar(BC) and organic farm residues(FR) at different application rates of 0.0%(control), 4.0% and 8.0%(weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.展开更多
文摘Application of biochar to soils changes soil physicochemical properties and stimulates the activities of soil microorganisms that influence soil quality and plant performance.Studying the response of soil microbial communities to biochar amendments is important for better understanding interactions of biochar with soil,as well as plants.However,the effect of biochar on soil microorganisms has received less attention than its influences on soil physicochemical properties.In this review,the following key questions are discussed:(i)how does biochar affect soil microbial activities,in particular soil carbon(C)mineralization,nutrient cycling,and enzyme activities?(ii)how do microorganisms respond to biochar amendment in contaminated soils?and(iii)what is the role of biochar as a growth promoter for soil microorganisms?Many studies have demonstrated that biochar-soil application enhances the soil microbial biomass with substantial changes in microbial community composition.Biochar amendment changes microbial habitats,directly or indirectly affects microbial metabolic activities,and modifies the soil microbial community in terms of their diversity and abundance.However,chemical properties of biochar,(especially pH and nutrient content),and physical properties such as pore size,pore volume,and specific surface area play significant roles in determining the efficacy of biochar on microbial performance as biochar provides suitable habitats for microorgan-isms.The mode of action of biochar leading to stimulation of microbial activities is complex and is influenced by the nature of biochar as well as soil conditions.
基金supported by the National Basic Research Program of China ("973" Project) (Grant Nos 2010CB226804, 2002CB412705)the National Natural Science Foundation of China (Grant No 50974125)+1 种基金the Natural Sciences & Engineering Research Council of Canada (PGS-D2-2006)Beijing Key Laboratory Projects
文摘The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster mechanisms of rock media.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science,ICT and Future Planning,No.2018R1C1B5029745(to HJC),2011-0030072(to YH),2018R1D1A1B07040282(to JJ),2018R1A2B6001123(to NYJ)
文摘Mitophagy is activated by a number of stimuli, including hypoxia, energy stress, and increased oxidative phosphorylation activity. Mitophagy is associated with oxidative stress conditions and central neurodegenerative diseases. Proper regulation of mitophagy is crucial for maintaining homeostasis; conversely, inadequate removal of mitochondria through mitophagy leads to the generation of oxidative species, including reactive oxygen species and reactive nitrogen species, resulting in various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. These diseases are most prevalent in older adults whose bodies fail to maintain proper mitophagic functions to combat oxidative species. As mitophagy is essential for normal body function, by targeting mitophagic pathways we can improve these disease conditions. The search for effective remedies to treat these disease conditions is an ongoing process, which is why more studies are needed. Additionally, more relevant studies could help establish therapeutic conditions, which are currently in high demand. In this review, we discuss how mitophagy plays a significant role in homeostasis and how its dysregulation causes neurodegeneration. We also discuss how combating oxidative species and targeting mitophagy can help treat these neurodegenerative diseases.
基金MZH acknowledges scholarship from the University of Newcastle,Australia,and Cooperative Research Centre for High Performance Soils(Soil CRC).
文摘Biochar,an environmentally friendly soil conditioner,is produced using several thermochemical processes.It has unique characteristics like high surface area,porosity,and surface charges.This paper reviews the fertilizer value of biochar,and its effects on soil properties,and nutrient use efficiency of crops.Biochar serves as an important source of plant nutrients,especially nitrogen in biochar produced from manures and wastes at low temperature(≤400℃).The phosphorus,potassium,and other nutrient contents are higher in manure/waste biochars than those in crop residues and woody biochars.The nutrient contents and pH of biochar are positively correlated with pyrolysis temperature,except for nitrogen content.Biochar improves the nutrient retention capacity of soil,which depends on porosity and surface charge of biochar.Biochar increases nitrogen retention in soil by reducing leaching and gaseous loss,and also increases phosphorus availability by decreasing the leaching process in soil.However,for potassium and other nutrients,biochar shows inconsistent(positive and negative)impacts on soil.After addition of biochar,porosity,aggregate stability,and amount of water held in soil increase and bulk density decreases.Mostly,biochar increases soil pH and,thus,influences nutrient availability for plants.Biochar also alters soil biological properties by increasing microbial populations,enzyme activity,soil respiration,and microbial biomass.Finally,nutrient use efficiency and nutrient uptake improve with the application of biochar to soil.Thus,biochar can be a potential nutrient reservoir for plants and a good amendment to improve soil properties.
基金supported by the National "863" Project of China
文摘A mobile molecular Doppler wind lidar at an eye-safe wavelength of 355 nm based on double-edge technique is being built in Hefei （China） for wind measurement from 10-to 40-km altitude. The structure of this lidar system is described. A triple Fabry-Perot etalon is employed as a frequency discriminator whose parameters are optimized. The receiver system is designed to achieve compactness and stability by putting in a standard 19-inch socket bench. Simulation results show that within the wind speed dynamic range of ±100 m/s, the horizontal wind errors due to noise are less than 1 m/s bdow 20-km altitude for 100-m vertical resolution, and less than 5.5 m/s from 20 km up to 40 km for 500-m vertical resolution with 400-mJ laser energy, 30-min temporal resolution, and a 45-cm aperture telescooe.
基金Supported by Institute of Wonkwang Medical Science in 2011
文摘AIM:To determine the utility of endoscopic ultrasoundguided biliary drainage(EUS-BD)with a fully covered self-expandable metal stent for managing malignant biliary stricture. METHODS:We collected data from 13 patients who presented with malignant biliary obstruction and underwent EUS-BD with a nitinol fully covered selfexpandable metal stent when endoscopic retrograde cholangiopancreatography(ERCP)fails.EUS-guided choledochoduodenostomy(EUS-CD)and EUS-guided hepaticogastrostomy(EUS-HG)was performed in 9 patients and 4 patients,respectively. RESULTS:The technical and functional success rate was 92.3%(12/13)and 91.7%(11/12),respectively. Using an intrahepatic approach(EUS-HG,n=4),there was mild peritonitis(n=1)and migration of the metal stent to the stomach(n=1).With an extrahepatic approach(EUS-CD,n=10),there was pneumoperitoneum(n=2),migration(n=2),and mild peritonitis (n=1).All patients were managed conservatively with antibiotics.During follow-up(range,1-12 mo),there was re-intervention(4/13 cases,30.7%)necessitated by stent migration(n=2)and stent occlusion(n=2). CONCLUSION:EUS-BD with a nitinol fully covered self-expandable metal stent may be a feasible and effective treatment option in patients with malignant biliary obstruction when ERCP fails.
基金Supported by The Korean Society of Gastroenterology Research Fund, No. 2005-1
文摘AIM： To investigate prevalence of C/onorchis sinensis in patients with gastrointestinal symptoms, and the relation of the infection to hepatobiliary diseases in 26 hospitals in Korea. METHODS： Consecutive patients who had been admitted to the Division of Gastroenterology with gastrointestinal symptoms were enrolled from March to April 2005. Of those who had been diagnosed with clonorchiasis, epidemiology and correlation between infection and hepatobiliary diseases were surveyed by questionnaire. RESULTS： Of 3080 patients with gastrointestinal diseases, 396 （12.9%） had clonorchiasis and 1140 patients （37.2%） had a history of eating raw freshwater fish. Of those with a history of raw freshwater fish ingestion, 238 （20.9%） patients had clonorchiasis. Cholangiocarcinoma was more prevalent in C. sinensis-infected patients than nonnfected patients [34/396 （8.6%） vs 145/2684 （5.4%）, P = 0.015]. Cholangiocarcinoma and clonorchiasis showed statistically significant positive cross-relation （P = 0.008）. Choledocholithiasis, cholecystolithiasis, cholangitis, hepatocellular carcinoma, and biliary pancreatitis did not correlate with clonorchiasis. CONCLUSION： Infection rate of clonorchiasis was still high in patients with gastrointestinal diseases in Korea, and has not decreased very much during the last two decades. Cholangiocarcinoma was related to clonorchiasis, which suggested an etiological role for the parasite.
文摘AIM: To investigate treatment outcome of Helicobacter pylori (H.pylori )-negative low-grade gastric mucosaassociated lymphoid tissue (MALT) lymphoma.METHODS: In this study,we retrospectively reviewed the clinical outcome and clinicopathologic factors of stage Ⅰ E H.pylori -negative low-grade gastric MALT lymphoma cases from August 1998 to June 2009.RESULTS: A total of eleven patients with H.pylori -negative low-grade gastric MALT lymphoma were enrolled in the study and received anti-H.pylori eradication treatment and/or radiotherapy or excisional therapy.Complete remission (CR) of gastric MALT lymphoma was achieved in all patients.The time to CR was 1-66 mo (median,1 mo).CONCLUSION: Eradication therapy may be offered as an initial treatment option even in cases of localized H.pylori -negative gastric MALT lymphoma.
基金the National Natural Science Foundation of China,No.39870850
文摘AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expre
文摘AIM:To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS:A total of 55 patients with MALTOMA from May 1992 to August 2002 were retrospectively reviewed. RESULTS:Complete remission was obtained in 24 (82.8%) of 29 patients treated with anti Helicobacter pylori (Hpylori) regimen only.The duration to reach complete remission was 12 months (85 percentile,2-33 months).Five patients showed complete remission with radiation therapy (26-86 months).Two of them were Hpyloritreatment failure cases. CONCLUSION:Hpylorieradication is an effective primary treatment option for low grade MALTOMA and radiation therapy could be considered in patients with no evidence of Hpyloriinfection or who do not respond to Hpylorieradication therapy 12 months after successful eradication.
基金Supported by the National Research Foundation of Korea Grant funded by the Korean Government,No.2014R1A5A2010008
文摘AIM To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus(DM).METHODS Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cancer. H&E stain and Masson's Trichrome stain were performed to assess the degree of fibrosis. Immunohistochemical staining using various antibodies was also performed [antibodies against protein gene product 9.5(PGP9.5), neuronal nitric oxide synthase(n NOS), vasoactive intestinal peptide(VIP), neurokinin-1(NK1) receptor, c-Kit, and platelet-derived growth factor receptor-alpha,(PDGFRα)]. Immunofluorescent staining and evaluation with confocal microscopy were also conducted.RESULTS Twenty-six controls and 35 diabetic patients(21 shortduration patients and 14 long-duration patients) were included. There were no significant differences in basic demographics between the two groups except in mean body mass index(BMI)(higher in the DM group). Proportions of moderate-to-severe intercellular fibrosis in the muscle layer were significantly higher in the DM group than in the control group(P < 0.01). On immunohistochemical staining, c-Kit- and PDGFRα-positive immunoreactivity were significantly decreased in the DM group compared with the control group(P < 0.05). There were no statistically significant differences in PGP9.5, n NOS, VIP, and neurokinin 1 expression. On immunofluorescent staining, cellularity of interstitial cells of Cajal(ICC) was observed to decrease with increasing duration of DM.CONCLUSION Our study suggests that increased intercellular fibrosis, loss of ICC, and loss of fibroblast-like cells are found in the smooth muscle of DM patients. These abnormalities may contribute to changes in gastric motor activity in patients with DM.
文摘Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(TKIs),sorafenib and lenvatinib,and to identify a novel therapeutic target for overcoming TKI resistance in hepatocellular carcinoma(HCC).Methods:We performed a systematic integrative analysis of publicly available gene expression datasets and whole-transcriptome sequencing data from 9 pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues,respectively,to identify key molecules that might induce resistance to TKIs.We then performed in vitro and in vivo experiments to validate selected targets and related mechanisms.The associations of plasma secreted phosphoprotein 1(SPP1)expression levels before sorafenib/lenvatinib treatment with progression-free survival(PFS)and overall survival(OS)of 54 patients with advanced HCC were evaluated using Kaplan-Meier and Cox regression analysis.Results:Bioinformatic analysis identified CAF-derived SPP1 as a candidate molecule driving TKI resistance.SPP1 inhibitors reversed CAF-induced TKI resistance in vitro and in vivo.CAF-derived SPP1 activated rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)through the integrin-protein kinase C-alpha(PKCα)signaling pathway and promoted epithelial-to-mesenchymal transition(EMT).A high plasma SPP1 level before TKI treatment was identified as an independent predictor of poor PFS(P=0.026)and OS(P=0.047)in patients with advanced HCC after TKI treatment.Conclusions:CAF-derived SPP1 enhances TKI resistance in HCC via bypass activation of oncogenic signals and EMT promotion.Its inhibition represents a promising therapeutic strategy against TKI resistance inHCC.Moreover,plasma SPP1 level before TKI treatment represents a potential biomarker for treatment response prediction.
基金Supported by the 2015 Yeungnam University Research Grant
文摘AIM To investigate the effect of Helicobacter pylori(H. pylori) status test and H. pylori eradication on the occurrence of metachronous gastric cancer(MGC) after endoscopic submucosal dissection(ESD) of early gastric cancer(EGC) and risk factors of MGC. METHODS The authors retrospectively reviewed the medical records of 433 patients(441 lesions) who underwent ESD for EGC from January 2005 to January 2015 in Yeungnam University Hospital. Patients were categorized into two groups; the H. pylori tested group(n = 257) and the H. pylori non-tested group(n = 176) based on performance of H. pylori status test after ESD of EGC. The H. pylori tested group was further categorized into three subgroups based on H. pylori status; the H. pylori-eradicated subgroup(n = 120), the H. pylori-persistent subgroup(n = 42), and the H. pylori-negative subgroup(n = 95). Incidences of MGC and risk factors of MGC were identified.RESULTS Median follow-up duration after ESD was 30.00 mo(range, 6-107 mo). Total 15 patients developed MGC during follow-up. MGC developed in 11 patients of the H. pylori tested group(7 in the H. pylori-negative subgroup, 3 in the H. pylori-eradicated subgroup, and 1 in the H. pylori-persistent subgroup) and 4 patients of the H. pylori non-tested group(P > 0.05). The risk factors of MGC were endoscopic mucosal atrophy in the H. pylori tested group and intestinal metaplasia in all patients. CONCLUSION H. pylori eradication and H. pylori status test seems to have no preventive effect on the development of MGC after ESD for EGC. The risk factors of MGC development were endoscopic mucosal atrophy in the H. pylori tested group alone and intestinal metaplasia in all patients.
文摘Ischemic colitis is the most common form of intestinal ischemia.It is a condition that is commonly seen in the elderly and among individuals with risk factors for ischemia.Common predisposing conditions for ischemic colitis are major vascular occlusion,small vessel disorder,shock,some medications,colonic obstructions and hematologic disorders.Ischemic colitis following colonoscopy is rare.Here,we report two cases of ischemic colitis after a routine screening colonoscopy in patients without risk factors for ischemia.
基金King Abdulazaiz City of Science and Technology(KACST)(grant no:AT-34-392),Riyadh,Kingdom of Saudi Arabia
文摘Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar(BC) and organic farm residues(FR) at different application rates of 0.0%(control), 4.0% and 8.0%(weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.
