Injuries to the spinal cord result in permanent disabilities that limit daily life activities.The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu...Injuries to the spinal cord result in permanent disabilities that limit daily life activities.The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries.Despite decades of research,there is still no efficient treatment for spinal cord injury.Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury.Among these,molecular compounds are currently being used for neurological recovery,with promising results.These molecules target the axon collapsed growth cone,the inhibitory microenvironment,the survival of neurons and glial cells,and the re-establishment of lost connections.In this review we focused on molecules that are being used,either in preclinical or clinical studies,to treat spinal cord injuries,such as drugs,growth and neurotrophic factors,enzymes,and purines.The mechanisms of action of these molecules are discussed,considering traumatic spinal cord injury in rodents and humans.展开更多
LiDAR data are becoming increasingly available,which has opened up many new applications.One such application is crop type mapping.Accurate crop type maps are critical for monitoring water use,estimating harvests and ...LiDAR data are becoming increasingly available,which has opened up many new applications.One such application is crop type mapping.Accurate crop type maps are critical for monitoring water use,estimating harvests and in precision agriculture.The traditional approach to obtaining maps of cultivated fields is by manually digitizing the fields from satellite or aerial imagery and then assigning crop type labels to each field-often informed by data collected during ground and aerial surveys.However,manual digitizing and labeling is time-consuming,expensive and subject to human error.Automated remote sensing methods is a cost-effective alternative,with machine learning gaining popularity for classifying crop types.This study evaluated the use of LiDAR data,Sentinel-2 imagery,aerial imagery and machine learning for differentiating five crop types in an intensively cultivated area.Different combinations of the three datasets were evaluated along with ten machine learning.The classification results were interpreted by comparing overall accuracies,kappa,standard deviation and f-score.It was found that LiDAR data successfully differentiated between different crop types,with XGBoost providing the highest overall accuracy of 87.8%.Furthermore,the crop type maps produced using the LiDAR data were in general agreement with those obtained by using Sentinel-2 data,with LiDAR obtaining a mean overall accuracy of 84.3%and Sentinel-2 a mean overall accuracy of 83.6%.However,the combination of all three datasets proved to be the most effective at differentiating between the crop types,with RF providing the highest overall accuracy of 94.4%.These findings provide a foundation for selecting the appropriate combination of remotely sensed data sources and machine learning algorithms for operational crop type mapping.展开更多
Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected ...Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.展开更多
Background: Blood pressure level is associated with the risk of clinical Alzheimer disease (AD), yet the underlying mechanisms are unclear. High blood pressure levels may cause cerebral small- vessel pathology, which ...Background: Blood pressure level is associated with the risk of clinical Alzheimer disease (AD), yet the underlying mechanisms are unclear. High blood pressure levels may cause cerebral small- vessel pathology, which contributes to cognitive decline in patients with AD. Alternatively, in persons with high blood pressure, increased numbers of neurofibrillary tangles and amyloid plaques at autopsy have also been observed, suggesting direct links between blood pressure and AD. Abstract:Objective: To investigate the association of blood pressure and markers of small- vessel disease (white matter lesions [WMLs] on MRI)- with hippocampal and amygdalar atrophy on MRI - potential in vivo indicators of Alzheimer pathology. Methods: In 1995 to 1996, 511 nondemented elderly subjects (age 60 to 90) underwent MRI. The extent of WMLs was assessed, and volumes of the hippocampus and amygdala were measured. Blood pressure levels were assessed at the time of MRI and 5 years before the MRI. Results: Higher diastolic blood pressure 5 years before MRI predicted more hippocampal atrophy in persons untreated for hypertension (per SD increase - 0.10 mL [95% CI - 0.19 to - 0.02, p = 0.02]). Conversely, in persons treated for hypertension, a low diastolic blood pressure was associated with more severe atrophy. Persons with more WMLs on MRI more often had severe atrophy of the hippocampus and amygdala. Conclusion: Blood pressure and indicators of small- vessel disease in the brain may be associated with atrophy of展开更多
AIM: To compare the safety of single-port laparoscopic cholecystectomies with standard four-port cholecystectomies.METHODS: Between January 2011 and December 2012 datas were gathered from 100 consecutive patients who ...AIM: To compare the safety of single-port laparoscopic cholecystectomies with standard four-port cholecystectomies.METHODS: Between January 2011 and December 2012 datas were gathered from 100 consecutive patients who received a single-port cholecystectomy. Patient baseline characteristics of all 100 single-port cholecystectomies were collected(body mass index, age, etc.) in a database. This group was compared with 100 age-matched patients who underwent a conventional laparoscopic cholecystectomy in the same period. Retrospectively, per- and postoperative data were added. The two groups were compared to each other using independent t-tests and χ2-tests, P values below 0.05 were considered significantly different.RESULTS: No differences were found between both groups regarding baseline characteristics. Operating time was significantly shorter in the total single-port group(42 min vs 62 min, P < 0.05); in procedures performed by surgeons the same trend was seen(45 min vs 59 min, P < 0.05). Peroperative complications between both groups were equal(3 in the single-port group vs 5 in the multiport group; P = 0.42). Although not significant less postoperative complications were seen in the single-port group compared with the multiport group(3 vs 9; P = 0.07). No statistically significant differences were found between both groupswith regard to length of hospital stay, readmissions and mortality. CONCLUSION: Single-port laparoscopic cholecystectomy has the potential to be a safe technique with a low complication rate, short in-hospital stay and comparable operating time. Single-port cholecystectomy provides the patient an almost non-visible scar while preserving optimal quality of surgery. Further prospective studies are needed to prove the safety of the single-port technique.展开更多
<b>Background:</b><b> </b>A high level of adherence to treatment is essential for cure and prevention of tuberculosis (TB) treatment resistance. <b>Methods:</b><b> </b>A...<b>Background:</b><b> </b>A high level of adherence to treatment is essential for cure and prevention of tuberculosis (TB) treatment resistance. <b>Methods:</b><b> </b>A Systematic review of 53 studies addressing the patient characteristics associated with TB medication non-adherence was performed. The publications were identified by searching the PubMed, World Health Organization (WHO), and Centers for Disease Control and Prevention (CDC) database, EmBase, Scopus database Arts, Humanities, Social Science database and Google scholar. Only English language publications were eligible. Potentially eligible studies were retrieved and the full articles were assessed. The potentially eligible studies were included if they concerned patients treated for tuberculosis, reported non adherence and reported on potential risk factors associated with non-adherence. <b>Results:</b> Factors that were most frequently consistently and statistically significantly related to non-adherence to tuberculosis treatment were: family income, patient movement and changing address or giving wrong address, tuberculosis relapse or multidrug-resistant TB (MDRTB), during intensive phase of treatment, history of default, treatment regimen (long course), response to treatment, homeless, stigma, seeking traditional healers, staff receptiveness, lack of directly observed therapy short course (DOTS), poor knowledge or lack of health education, side effects of drugs, feeling better, alcohol intake and lack of family and social support. <b>Conclusions:</b> Non-adherence to tuberculosis treatment was influenced by several factors.展开更多
After spinal cord injury （SCI）, a cascade of events begins. At first, there is physical damage with disruption of the blood-brain barrier （BBB） and the integrity of the nervous tissue. The disruption of central ne...After spinal cord injury （SCI）, a cascade of events begins. At first, there is physical damage with disruption of the blood-brain barrier （BBB） and the integrity of the nervous tissue. The disruption of central ner- vous system （CNS） BBB alters the endothelial permeability, the protein and chemokines expression and the propensity to release in situ inflam- matory cytokines, overcoming anti-inflammatory signals, facilitating the attraction and entry of immune system cells into the injured spinal cord parenchyma （Gaudet et al., 2011）. As a result, there is a neuroin- flammatory response with changes in blood flow, edema, cell infiltra- tion, apoptosis and release of axonal growth inhibitory factors. Nerve function loss occurs when the nerve impulse propagation is interrupted and do not reach its target. This disorder encompasses neuron and glia apoptosis, accompanied by Wallerian degeneration of disconnected axons, and CNS cells exposure to a hostile microenvironment that hampers axon regeneration （Mautes et al., 2000; Harkey et al., 2003）.展开更多
AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participant...AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participants were randomised into either circuit exercise training(EX;n = 13;3 h/wk without changes in dietary habits),or dietary energy restriction(ER) without changes in structured physical activity(ER;n = 8).Respiratory quotient(RQ) and whole-body fat oxidation rates(Fatox) were determined by indirect calorimetry under basal,insulin-stimulated and exercise conditions.Severity of disease and steatosis was determined by liver histology;hepatic Fatox was estimated from plasma β-hydroxybutyrate co.ncentrations;cardiorespiratory fitness was expressed as VO2 peak.Complete-case analysis was performed(EX:n = 10;ER:n = 6).RESULTS Hepatic steatosis and NAFLD activity score decreased with ER but not with EX.β-hydroxybutyrate concentrations increased significantly in response to ER(0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L,P = 0.03) but remained unchanged in response to EX(0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L,P = 0.39).Basal RQ decreased(P = 0.05) in response.to EX,while this change was not significant after ER(P = 0.38).VO_(2peak)(P < 0.001) and maximal Fa_(tox) during aerobic exercise(P = 0.03) improved with EX but not with ER(P > 0.05).The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis(r =-0.56,P = 0.04).CONCLUSION ER and EX lead to specific benefits on fat metabolism of patients with NAFLD.Increased hepatic Fat_(ox) in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.展开更多
The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon. The Capacitated Arc Routing Prob...The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon. The Capacitated Arc Routing Problem (CARP) is defined on an undirected network in which a fleet of identical vehicles is based at a depot node. A subset of edges, called tasks, must be serviced by a vehicle. The CARP consists of determining a set of feasible vehicle trips that minimizes the total cost of traversed edges. The PCARP involves the assignment of tasks to periods and the determination of vehicles trips in each period, to minimize the total cost on the whole horizon. This new problem arises in various real life applications such as waste collection, mail delivery, etc. In this paper, a new linear programming model and preliminary lower bounds based on graph transformation are proposed. A meta-heuristic approach - Scatter Search (SS) is developed for the PCARP and evaluated on a large variety of instances.展开更多
目的比较早期由静脉转换成口服抗生素与常规静脉使用7天抗生素治疗严重社区获得性肺炎(CAP)的疗效。设计多中心随机对照试验。地点荷兰5家教学医院和2所大学的医学中心。参加者非 ICU 住院的严重 CAP 患者302例,其中265例满足研究要求...目的比较早期由静脉转换成口服抗生素与常规静脉使用7天抗生素治疗严重社区获得性肺炎(CAP)的疗效。设计多中心随机对照试验。地点荷兰5家教学医院和2所大学的医学中心。参加者非 ICU 住院的严重 CAP 患者302例,其中265例满足研究要求。干预静脉抗生素治疗3天,病情稳定后换成口服抗生素,或静脉使用抗生素治疗7天。主要评价结果临床治愈和住院天数。结果 302例患者被随机分组(平均年龄69.5岁,标准差14.0),肺炎严重度评分平均112.7(26.0)。37例患者因为提前3天退出而未纳入分析,对其余265例患者进行分析研究。第28天的死亡率在干预组是4%,对照组是6%(平均差2%,95%可信区间-3%～8%)。临床治愈率在干预组是83%,对照组是85%(2%;-7%～10%)。与对照组相比,干预组患者静脉治疗时间为3.4天[3.6(1.5)比7.0(2.0)天;2.8～3.9],患者住院天数减少1.9天[9.6(5.0)比11.5(4.9)天;0.6～3.2]。结论早期将抗生素由静脉应用转换成口服治疗严重 CAP 是安全的,并且可以减少住院时间2天。试验注册号临床试验 NCT00273676。展开更多
Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one inte...Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the Poyang Lake national nature reserve, China. The daily global solar radiation records at Nanchang meteorological station and daily sunshine duration measurements at nine meteorological stations around Poyang Lake were obtained to achieve the objective. Two extrapolation methods of PARs using recorded and estimated global solar radiation at Nanchang station and three stations （Yongxiu, Xingzi and Duchang） near the nature reserve were carried out, respectively, and a spatial interpolation method combining triangulated irregular network （TIN） and inverse distance weighting （IDW） was imple- mented to estimate daily PAR. The performance evaluation of the three methods using the PARs measured at Dahuchi Conservation Station （day number of measurement = 105 days） revealed that： （1） the spatial interpolation method achieved the best PAR estima- tion （R2 - 0.89, s.c. = 0.99, F= 830.02, P 〈 0.001 ）; （2） the extrapolation method from Nanchang station obtained an unbiased result （R2 = 0.88, s.c. = 0.99, F = 745.29, P 〈 0.001）; however, （3） the extrapolation methods from Yongxiu, Xingzi and Duchang stations were not suitable for this specific site for their biased estimations. Considering the assumptions and principles supporting the extrapolation and interpolation methods, the authors conclude that the spatial interpolation method produces more reliable results than the extrapolation methods and holds the greatest potential in all tested methods, and more PAR measurements should be recorded to evaluate the seasonal, yearly and spatial stabilities of these models for their application to the whole nature reserve of Poyang Lake.展开更多
基金supported by CAPESFaperj+1 种基金CNPq‘‘National Institute of Science and Technology for Regenerative Medicine”, CNPq, Brazil(to AMBM)
文摘Injuries to the spinal cord result in permanent disabilities that limit daily life activities.The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries.Despite decades of research,there is still no efficient treatment for spinal cord injury.Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury.Among these,molecular compounds are currently being used for neurological recovery,with promising results.These molecules target the axon collapsed growth cone,the inhibitory microenvironment,the survival of neurons and glial cells,and the re-establishment of lost connections.In this review we focused on molecules that are being used,either in preclinical or clinical studies,to treat spinal cord injuries,such as drugs,growth and neurotrophic factors,enzymes,and purines.The mechanisms of action of these molecules are discussed,considering traumatic spinal cord injury in rodents and humans.
基金This work forms part of a larger project titled“Salt Accumulation and Waterlogging Monitoring System(SAWMS)Development”which was initiated and funded by the Water Research Commission(WRC)of South Africa(contract number K5/2558//4)More information about this project is available in WRC Report No TT 782/18,titled SALT ACCUMULATION AND WATERLOGGING MONITORING SYSTEM(SAWMS)DEVELOPMENT(ISBN 978-0-6392-0084-2)+1 种基金available at www.wrc.org.za.This work was also supported by the National Research Foundation(grant number 112300)The authors would also like to thank www.linguafix.net for their language editing services.
文摘LiDAR data are becoming increasingly available,which has opened up many new applications.One such application is crop type mapping.Accurate crop type maps are critical for monitoring water use,estimating harvests and in precision agriculture.The traditional approach to obtaining maps of cultivated fields is by manually digitizing the fields from satellite or aerial imagery and then assigning crop type labels to each field-often informed by data collected during ground and aerial surveys.However,manual digitizing and labeling is time-consuming,expensive and subject to human error.Automated remote sensing methods is a cost-effective alternative,with machine learning gaining popularity for classifying crop types.This study evaluated the use of LiDAR data,Sentinel-2 imagery,aerial imagery and machine learning for differentiating five crop types in an intensively cultivated area.Different combinations of the three datasets were evaluated along with ten machine learning.The classification results were interpreted by comparing overall accuracies,kappa,standard deviation and f-score.It was found that LiDAR data successfully differentiated between different crop types,with XGBoost providing the highest overall accuracy of 87.8%.Furthermore,the crop type maps produced using the LiDAR data were in general agreement with those obtained by using Sentinel-2 data,with LiDAR obtaining a mean overall accuracy of 84.3%and Sentinel-2 a mean overall accuracy of 83.6%.However,the combination of all three datasets proved to be the most effective at differentiating between the crop types,with RF providing the highest overall accuracy of 94.4%.These findings provide a foundation for selecting the appropriate combination of remotely sensed data sources and machine learning algorithms for operational crop type mapping.
基金We acknowledge the funding from the Canada Research Chairs program,the National Sciences and Engineering Research Council of Canada and Genome CanadaZM was supported in part by a Killam Predoctoral Scholarship from Dalhousie University.
文摘Grapes are one of the most economically and culturally important crops worldwide,and they have been bred for both winemaking and fresh consumption.Here we evaluate patterns of diversity across 33 phenotypes collected over a 17-year period from 580 table and wine grape accessions that belong to one of the world’s largest grape gene banks,the grape germplasm collection of the United States Department of Agriculture.We find that phenological events throughout the growing season are correlated,and quantify the marked difference in size between table and wine grapes.By pairing publicly available historical phenotype data with genome-wide polymorphism data,we identify large effect loci controlling traits that have been targeted during domestication and breeding,including hermaphroditism,lighter skin pigmentation and muscat aroma.Breeding for larger berries in table grapes was traditionally concentrated in geographic regions where Islam predominates and alcohol was prohibited,whereas wine grapes retained the ancestral smaller size that is more desirable for winemaking in predominantly Christian regions.We uncover a novel locus with a suggestive association with berry size that harbors a signature of positive selection for larger berries.Our results suggest that religious rules concerning alcohol consumption have had a marked impact on patterns of phenomic and genomic diversity in grapes.
文摘Background: Blood pressure level is associated with the risk of clinical Alzheimer disease (AD), yet the underlying mechanisms are unclear. High blood pressure levels may cause cerebral small- vessel pathology, which contributes to cognitive decline in patients with AD. Alternatively, in persons with high blood pressure, increased numbers of neurofibrillary tangles and amyloid plaques at autopsy have also been observed, suggesting direct links between blood pressure and AD. Abstract:Objective: To investigate the association of blood pressure and markers of small- vessel disease (white matter lesions [WMLs] on MRI)- with hippocampal and amygdalar atrophy on MRI - potential in vivo indicators of Alzheimer pathology. Methods: In 1995 to 1996, 511 nondemented elderly subjects (age 60 to 90) underwent MRI. The extent of WMLs was assessed, and volumes of the hippocampus and amygdala were measured. Blood pressure levels were assessed at the time of MRI and 5 years before the MRI. Results: Higher diastolic blood pressure 5 years before MRI predicted more hippocampal atrophy in persons untreated for hypertension (per SD increase - 0.10 mL [95% CI - 0.19 to - 0.02, p = 0.02]). Conversely, in persons treated for hypertension, a low diastolic blood pressure was associated with more severe atrophy. Persons with more WMLs on MRI more often had severe atrophy of the hippocampus and amygdala. Conclusion: Blood pressure and indicators of small- vessel disease in the brain may be associated with atrophy of
文摘AIM: To compare the safety of single-port laparoscopic cholecystectomies with standard four-port cholecystectomies.METHODS: Between January 2011 and December 2012 datas were gathered from 100 consecutive patients who received a single-port cholecystectomy. Patient baseline characteristics of all 100 single-port cholecystectomies were collected(body mass index, age, etc.) in a database. This group was compared with 100 age-matched patients who underwent a conventional laparoscopic cholecystectomy in the same period. Retrospectively, per- and postoperative data were added. The two groups were compared to each other using independent t-tests and χ2-tests, P values below 0.05 were considered significantly different.RESULTS: No differences were found between both groups regarding baseline characteristics. Operating time was significantly shorter in the total single-port group(42 min vs 62 min, P < 0.05); in procedures performed by surgeons the same trend was seen(45 min vs 59 min, P < 0.05). Peroperative complications between both groups were equal(3 in the single-port group vs 5 in the multiport group; P = 0.42). Although not significant less postoperative complications were seen in the single-port group compared with the multiport group(3 vs 9; P = 0.07). No statistically significant differences were found between both groupswith regard to length of hospital stay, readmissions and mortality. CONCLUSION: Single-port laparoscopic cholecystectomy has the potential to be a safe technique with a low complication rate, short in-hospital stay and comparable operating time. Single-port cholecystectomy provides the patient an almost non-visible scar while preserving optimal quality of surgery. Further prospective studies are needed to prove the safety of the single-port technique.
文摘<b>Background:</b><b> </b>A high level of adherence to treatment is essential for cure and prevention of tuberculosis (TB) treatment resistance. <b>Methods:</b><b> </b>A Systematic review of 53 studies addressing the patient characteristics associated with TB medication non-adherence was performed. The publications were identified by searching the PubMed, World Health Organization (WHO), and Centers for Disease Control and Prevention (CDC) database, EmBase, Scopus database Arts, Humanities, Social Science database and Google scholar. Only English language publications were eligible. Potentially eligible studies were retrieved and the full articles were assessed. The potentially eligible studies were included if they concerned patients treated for tuberculosis, reported non adherence and reported on potential risk factors associated with non-adherence. <b>Results:</b> Factors that were most frequently consistently and statistically significantly related to non-adherence to tuberculosis treatment were: family income, patient movement and changing address or giving wrong address, tuberculosis relapse or multidrug-resistant TB (MDRTB), during intensive phase of treatment, history of default, treatment regimen (long course), response to treatment, homeless, stigma, seeking traditional healers, staff receptiveness, lack of directly observed therapy short course (DOTS), poor knowledge or lack of health education, side effects of drugs, feeling better, alcohol intake and lack of family and social support. <b>Conclusions:</b> Non-adherence to tuberculosis treatment was influenced by several factors.
文摘After spinal cord injury （SCI）, a cascade of events begins. At first, there is physical damage with disruption of the blood-brain barrier （BBB） and the integrity of the nervous tissue. The disruption of central ner- vous system （CNS） BBB alters the endothelial permeability, the protein and chemokines expression and the propensity to release in situ inflam- matory cytokines, overcoming anti-inflammatory signals, facilitating the attraction and entry of immune system cells into the injured spinal cord parenchyma （Gaudet et al., 2011）. As a result, there is a neuroin- flammatory response with changes in blood flow, edema, cell infiltra- tion, apoptosis and release of axonal growth inhibitory factors. Nerve function loss occurs when the nerve impulse propagation is interrupted and do not reach its target. This disorder encompasses neuron and glia apoptosis, accompanied by Wallerian degeneration of disconnected axons, and CNS cells exposure to a hostile microenvironment that hampers axon regeneration （Mautes et al., 2000; Harkey et al., 2003）.
基金Supported by The National Health and Medical Research Council of Australiathe Lions Medical Research Foundation
文摘AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participants were randomised into either circuit exercise training(EX;n = 13;3 h/wk without changes in dietary habits),or dietary energy restriction(ER) without changes in structured physical activity(ER;n = 8).Respiratory quotient(RQ) and whole-body fat oxidation rates(Fatox) were determined by indirect calorimetry under basal,insulin-stimulated and exercise conditions.Severity of disease and steatosis was determined by liver histology;hepatic Fatox was estimated from plasma β-hydroxybutyrate co.ncentrations;cardiorespiratory fitness was expressed as VO2 peak.Complete-case analysis was performed(EX:n = 10;ER:n = 6).RESULTS Hepatic steatosis and NAFLD activity score decreased with ER but not with EX.β-hydroxybutyrate concentrations increased significantly in response to ER(0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L,P = 0.03) but remained unchanged in response to EX(0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L,P = 0.39).Basal RQ decreased(P = 0.05) in response.to EX,while this change was not significant after ER(P = 0.38).VO_(2peak)(P < 0.001) and maximal Fa_(tox) during aerobic exercise(P = 0.03) improved with EX but not with ER(P > 0.05).The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis(r =-0.56,P = 0.04).CONCLUSION ER and EX lead to specific benefits on fat metabolism of patients with NAFLD.Increased hepatic Fat_(ox) in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.
文摘The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon. The Capacitated Arc Routing Problem (CARP) is defined on an undirected network in which a fleet of identical vehicles is based at a depot node. A subset of edges, called tasks, must be serviced by a vehicle. The CARP consists of determining a set of feasible vehicle trips that minimizes the total cost of traversed edges. The PCARP involves the assignment of tasks to periods and the determination of vehicles trips in each period, to minimize the total cost on the whole horizon. This new problem arises in various real life applications such as waste collection, mail delivery, etc. In this paper, a new linear programming model and preliminary lower bounds based on graph transformation are proposed. A meta-heuristic approach - Scatter Search (SS) is developed for the PCARP and evaluated on a large variety of instances.
文摘目的比较早期由静脉转换成口服抗生素与常规静脉使用7天抗生素治疗严重社区获得性肺炎(CAP)的疗效。设计多中心随机对照试验。地点荷兰5家教学医院和2所大学的医学中心。参加者非 ICU 住院的严重 CAP 患者302例,其中265例满足研究要求。干预静脉抗生素治疗3天,病情稳定后换成口服抗生素,或静脉使用抗生素治疗7天。主要评价结果临床治愈和住院天数。结果 302例患者被随机分组(平均年龄69.5岁,标准差14.0),肺炎严重度评分平均112.7(26.0)。37例患者因为提前3天退出而未纳入分析,对其余265例患者进行分析研究。第28天的死亡率在干预组是4%,对照组是6%(平均差2%,95%可信区间-3%～8%)。临床治愈率在干预组是83%,对照组是85%(2%;-7%～10%)。与对照组相比,干预组患者静脉治疗时间为3.4天[3.6(1.5)比7.0(2.0)天;2.8～3.9],患者住院天数减少1.9天[9.6(5.0)比11.5(4.9)天;0.6～3.2]。结论早期将抗生素由静脉应用转换成口服治疗严重 CAP 是安全的,并且可以减少住院时间2天。试验注册号临床试验 NCT00273676。
基金Supported by the National Natural Science Foundation of China (No. 40971191)the Scientific Research Starting Foundation of Ministry of Education of China for Returned Overseas Chinese Scholars+1 种基金the Special Foundation of Ministry of Finance of China for Nonprofit Research of Forestry Industry (No.200904001)the International Institute for Geo-information Science and Earth Observation (ITC),the Netherlands
文摘Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the Poyang Lake national nature reserve, China. The daily global solar radiation records at Nanchang meteorological station and daily sunshine duration measurements at nine meteorological stations around Poyang Lake were obtained to achieve the objective. Two extrapolation methods of PARs using recorded and estimated global solar radiation at Nanchang station and three stations （Yongxiu, Xingzi and Duchang） near the nature reserve were carried out, respectively, and a spatial interpolation method combining triangulated irregular network （TIN） and inverse distance weighting （IDW） was imple- mented to estimate daily PAR. The performance evaluation of the three methods using the PARs measured at Dahuchi Conservation Station （day number of measurement = 105 days） revealed that： （1） the spatial interpolation method achieved the best PAR estima- tion （R2 - 0.89, s.c. = 0.99, F= 830.02, P 〈 0.001 ）; （2） the extrapolation method from Nanchang station obtained an unbiased result （R2 = 0.88, s.c. = 0.99, F = 745.29, P 〈 0.001）; however, （3） the extrapolation methods from Yongxiu, Xingzi and Duchang stations were not suitable for this specific site for their biased estimations. Considering the assumptions and principles supporting the extrapolation and interpolation methods, the authors conclude that the spatial interpolation method produces more reliable results than the extrapolation methods and holds the greatest potential in all tested methods, and more PAR measurements should be recorded to evaluate the seasonal, yearly and spatial stabilities of these models for their application to the whole nature reserve of Poyang Lake.
