A pollen study was conducted on an alpine marsh sediment in the Son Kul Basin and was allowed to reconstruct changes in vegetation dynamics and climatic information in the western Tianshan Mountains during the past 20...A pollen study was conducted on an alpine marsh sediment in the Son Kul Basin and was allowed to reconstruct changes in vegetation dynamics and climatic information in the western Tianshan Mountains during the past 2000 years.Pollen diagram reveals that regional vegetation is dominated by alpine meadow in the past 2000 years,being similar with modern vegetation components in the basin.The Artemisia/Chenopodiaceae-indicated moisture exhibits a warm-dry Roman Warm Period(RWP,~0-~500 AD),a cold-dry Dark Ages Cold Period(DACP,~500-~800 AD),a warm-wet Medieval Warm Period(MWP,~800-~1350 AD),a cold-dry Little Ice Age(LIA,~1350-~1850 AD)and a warm-dry Current Warm Period(CWP,since~1850 AD).Our pollen-based moisture reconstructions are supported by other nearby moisture records.Combined with other pollen data in the western Tianshan Mountains,we found that the vegetation was relatively stable before~1650-~1750 AD and the anthropogenic activities obviously intensified afterwards(especially at the middle-elevation sites).Further work involving more and higher-resolution palaeovegetation records would contribute to fully understand the information on the complex links between environmental,climatic and anthropogenic changes in the western Tianshan Mountains.展开更多
The Fourth Assessment Report of IPCC(IPCC AR4)concluded that average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than that of any other 50-year period in the las...The Fourth Assessment Report of IPCC(IPCC AR4)concluded that average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than that of any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years.However,after evaluating Global or Northern Hemisphere temperature change series derived from ice cores,tree rings,展开更多
Over the past 2000 years,a high-resolution pollen record from the Yushenkule Peat(46°45′-46°57′N,90°46′-90°61′E,2374 m a.s.l.)in the south-eastern Altai Mountains of northwestern China has been...Over the past 2000 years,a high-resolution pollen record from the Yushenkule Peat(46°45′-46°57′N,90°46′-90°61′E,2374 m a.s.l.)in the south-eastern Altai Mountains of northwestern China has been used to explore the changes in vegetation and climate.The regional vegetation has been dominated by alpine meadows revealed from pollen diagrams over the past 2000 years.The pollen-based climate was warm and wet during the Roman Warm Period(0-520 AD),cold and wet during the Dark Age Cold Period(520-900 AD),warm and wet during the Medieval Warm Period(900-1300 AD),and cold and dry during the Little Ice Age(1300-1850 AD).Combined with other pollen data from the Altai Mountains,we found that the percentage of arboreal pollen showed a reduced trend along the NW-SE gradient with decreasing moisture and increasing climatic continentality of the Altai Mountains over the past 2000 years;this is consistent with modern distributions of taiga forests.We also found that the taiga(Pinus forest)have spread slightly,while the steppe(Artemisia,Poaceae and Chenopodiaceae)have recovered significantly in the Altai Mountains over the past 2000 years.In addition,the relatively warm-wet climate may promote high grassland productivity and southward expansion of steppe,which favors the formation of Mongol political and military power.展开更多
工程人员常通过对比设计软件与有限元软件的分析结果,以验算和校核结构设计的合理性。然而,由于软件分析内核的差异,设计软件与有限元软件之间的模型信息往往难以直接传递并转化。针对SAP2000结构设计分析软件向ANSYS有限元分析软件的...工程人员常通过对比设计软件与有限元软件的分析结果,以验算和校核结构设计的合理性。然而,由于软件分析内核的差异,设计软件与有限元软件之间的模型信息往往难以直接传递并转化。针对SAP2000结构设计分析软件向ANSYS有限元分析软件的模型转化问题,基于Python语言和APDL参数化设计语言,编译并开发了STAMT V1.0(SAP2000 To ANSYS Model Transformation V1.0)模型转化程序。相比已有转化程序,STAMT程序实现了更多单元类型、材料属性、截面类型、荷载形式的转化,提高了模型转化的通用性。其次,其涵盖了节点坐标系变换、梁单元坐标系变换、梁端自由度释放、创建刚性域等必备功能,进一步满足了模型转化过程中的功能性需求。然后,采用先建立几何模型后生成有限元模型的转化思路,实现了梁单元网格数量的自定义以及板壳荷载向梁的传递,软件操作界面简洁,便于工程人员的使用。最后,通过单层工业厂房和多层框架结构的两个算例分析,得到转化后模型的质量与原模型一致,前5阶周期的平均误差不超过3%,满足精度要求。研究分析验证了STAMT程序可实现SAP2000模型向ANSYS模型的准确、快速转化。展开更多
Using 24 proxy temperature series,the rates of temperature change in China are analyzed at the 30-to 100-year scales for the past 2000 years and at the 10-year scale for the past 500 years.The results show that,at the...Using 24 proxy temperature series,the rates of temperature change in China are analyzed at the 30-to 100-year scales for the past 2000 years and at the 10-year scale for the past 500 years.The results show that,at the 100-year scale,the warming rate for the whole of China in the 20th century was only 0.6±1.6°C/100 a (interval at the 95% confidence level,which is used hereafter),while the peak warming rate for the period from the Little Ice Age (LIA) to the 20th century reached 1.1±1.2°C/100 a,which was the greatest in the past 500 years and probably the past 2000 years.At the 30-year scale,warming in the 20th century was quite notable,but the peak rate was still less than rates for previous periods,such as the rapid warming from the LIA to the 20th century and from the 270s-290s to 300s-320s.At the 10-year scale,the warming in the late 20th century was very evident,but it might not be unusual in the context of warming over the past 500 years.The exact timing,duration and magnitude of the warming peaks varied from region to region at all scales.The peak rates of the 100-year scale warming in the AD 180s-350s in northeastern China as well as those in the 260s-410s and 500s-660s in Tibet were all greater than those from the mid-19th to 20th century.Meanwhile,the rates of the most rapid cooling at scales of 30 to 100 years in the LIA were prominent,but they were also not unprecedented in the last 2000 years.At the 10-year scale,for the whole of China,the most rapid decadal cooling in the 20th century was from the 1940s to 1950s with a rate of 0.3±0.6°C/10 a,which was similar to rates for periods before the 20th century.For all regions,the rates of most rapid cooling in the 20th century were all less than those for previous periods.展开更多
The general characteristics of climate changes over the past 2000 years in China,regional differences and uncertainties were analyzed based on the recently peer-reviewed high time-resolution climatic reconstructions.T...The general characteristics of climate changes over the past 2000 years in China,regional differences and uncertainties were analyzed based on the recently peer-reviewed high time-resolution climatic reconstructions.The results showed that there exists four warm periods of the temperature variation in China since the Qin Dynasty,including the western and eastern Han Dynasties(200 BC-AD 180),the Sui and Tang dynasties(541-810),the Song and Yuan dynasties(931-1320),and the 20th century,and three cold phases involving the Wei,Jin,and North-South Dynasties(181-540),the late Tang Dynasty(811-930),and the Ming and Qing dynasties(1321-1920).The Song and Yuan warm period is consistent with the Medieval Warm Period over the Northern Hemisphere,and the cold phases of the North-South Dynasties and the Ming and Qing dynasties are paralleled to the Dark Ages Cold Period and the Little Ice Age,respectively.The 13th-15th century could be a shift to the wet condition of the climate,and the low precipitation variability is exhibited in western China prior to 1500.In the context of the climate warming,the pattern of the drought in north and flood in south is prevalent over the eastern China.In addition,the published reconstructions have a high level of confidence for the past 500 years,but large uncertainties exist prior to the 16th century.展开更多
随着经济发展与城镇化快速推进,中国居民膳食模式发生显著转变,并产生了严重的资源环境后果。为识别城乡居民食物消费碳-水足迹的关键驱动因素,缓解水资源消耗,助力双碳目标实现,该研究测算并对比分析了中国31(30)省市2000—2020年城乡...随着经济发展与城镇化快速推进,中国居民膳食模式发生显著转变,并产生了严重的资源环境后果。为识别城乡居民食物消费碳-水足迹的关键驱动因素,缓解水资源消耗,助力双碳目标实现,该研究测算并对比分析了中国31(30)省市2000—2020年城乡居民人均食物消费碳-水足迹,通过对数平均迪式指数算法(logarithmic mean index method,LMDI)对碳-水足迹进行了驱动因素分解。结果显示:2000—2020年中国城镇人均食物消费碳足迹(水足迹)增加了29.63%(32.94%),农村碳足迹(水足迹)增加了4.59%(7.91%)。从空间演变来看,城镇人均食物消费碳-水足迹较高的地区由沿海省份逐渐扩散至内陆,而农村呈南北高-中间低的分布格局。从驱动因素来看,经济水平是城乡居民食物消费碳-水足迹增加的主要动因,且消费水平表现为抑制作用;人口城镇化驱动城镇居民食物消费碳-水足迹增加,而在农村起到抑制作用。该研究从促进食物消费结构转型,多渠道拓宽食物来源等方面提出建议,旨在促进中国城乡居民食物可持续消费。展开更多
The spatial patterns of precipitation anomalies during five 30-yr warm periods of 691-720, 1231-1260, 1741-1770, 1921-1950, and 1981-2000 were investigated using a dryness/wetness grading dataset covering 48 stations ...The spatial patterns of precipitation anomalies during five 30-yr warm periods of 691-720, 1231-1260, 1741-1770, 1921-1950, and 1981-2000 were investigated using a dryness/wetness grading dataset covering 48 stations from Chinese historical documents and 22 precipitation proxy series from natural archives. It was found that the North China Plain (approximately 35 -40 N, east of 105 E) was dry in four warm periods within the centennial warm epochs of 600-750, the Medieval Warm Period (about 900-1300) and after 1900. A wet condition prevailed over most of China during 1741-1770, a 30-yr warm peak that occurred during the Little Ice Age (about 1650-1850). The spatial pattern of the precipitation anomaly in 1981-2000 over East China (25 -40 N, east of 105 E) is roughly consistent with that in 1231-1260, but a difference in the precipitation anomaly appeared over the Tibetan Plateau. The spatial patterns of the precipitation anomalies over China varied between all five 30-yr warm periods, which implies that the matching pattern between temperature and precipitation change is multiform, and the precipitation anomaly could be positive or negative when a decadal warm climate occurs in different climate epochs. This result may provide a primary reference for the mechanism detection and climate simulation of the precipitation anomaly of the future warm climate.展开更多
Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to 2021.It also aimed to recommend targeted interventions for the prevention and treatment of HIV/A...Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to 2021.It also aimed to recommend targeted interventions for the prevention and treatment of HIV/AIDS in elderly patients.Methods Data on newly reported cases of PLWHA,aged≥50 years in China from 2018 to 2021,were collected using the CRIMS.Trend tests and spatial analyses were also conducted.Results Between 2018 and 2021,237,724 HIV/AIDS cases were reported among patients aged≥50 years in China.The main transmission route was heterosexual transmission(91.24%).Commercial heterosexual transmission(CHC)was the primary mode of transmission among males,while non-marital non-CHC([NMNCHC];60.59%)was the prevalent route in women.The proportion of patients with CHC decreased over time(Z=67.716,P<0.01),while that of patients with NMNCHC increased(Z=153.05,P<0.01).The sex ratio varied among the different modes of infection,and it peaked at 17.65 for CHC.The spatial analysis indicated spatial clustering,and the high-high clustering areas were mainly distributed in the southwestern and central-southern provinces.Conclusion In China,PLWHA,aged≥50 years,were predominantly infected through heterosexual transmission.The primary modes of infection were CHC and NMNCHC.There were variations in the sex ratio among different age groups,infected through various sexual behaviors.HIV/AIDS cases exhibited spatial clustering.Based on these results,the expansion of HIV testing,treatment,and integrated behavioral interventions in high-risk populations is recommended to enhance disease detection in key regions.展开更多
The objectives of this work were to evaluate the surgical activities carried out in the general surgery department of the Reference Health Center of Commune I of Bamako, to describe the sociodemographic characteristic...The objectives of this work were to evaluate the surgical activities carried out in the general surgery department of the Reference Health Center of Commune I of Bamako, to describe the sociodemographic characteristics of the operated patients, to determine the main pathologies encountered and to evaluate qualitatively the result of the treatment. In order to improve performance, and the quality of care, and to identify common pathologies in the surgical department, we undertook a retrospective study on surgical activities from January 2009 to December 2010. At the end of this study, out of 474 men and 187 women (equal sex ratio 2.53);we were able to determine the frequency of surgical pathologies. Farmers, housewives and pupils/students were the most represented with 25.9% respectively;20% and 13.3%. The most frequently observed pathologies were wall hernia (44.8%), prostate adenoma (12%) and acute appendicitis (10.5%). The average length of hospitalization was 3.43 days. Infectious complications affected 25 patients (3.8% of cases) and a death rate of 0.45% (i.e. 3 patients). The average cost of care was 53,500 FCFA. Indeed, the reality of surgical practice in health centers was not the same because of the level of skills of practicing surgeons.展开更多
BACKGROUND The quality-adjusted life year(QALY)is a metric that is increasingly used today in the field of health economics to evaluate the value of different medical treatments and procedures.Surgical waiting lists(S...BACKGROUND The quality-adjusted life year(QALY)is a metric that is increasingly used today in the field of health economics to evaluate the value of different medical treatments and procedures.Surgical waiting lists(SWLs)represent a pressing problem in public healthcare.The QALY measure has rarely been used in the context of surgery.It would be interesting to know how many QALYs are lost by patients on SWLs.AIM To investigate the relationship between QALYs and SWLs in a systematic review of the scientific literature.METHODS The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement.An unlimited search was carried out in PubMed,updated on January 19,2024.Data on the following variables were investigated and analyzed:Specialty,country of study,procedure under study,scale used to measure QALYs,the use of a theoretical or real-life model,objectives of the study and items measured,the economic value assigned to the QALY in the country in question,and the results and conclusions published.RESULTS Forty-eight articles were selected for the study.No data were found regarding QALYs lost on SWLs.The specialties in which QALYs were studied the most in relation to the waiting list were urology and general surgery,with 15 articles each.The country in which the most studies of QALYs were carried out was the United States(n=21),followed by the United Kingdom(n=9)and Canada(n=7).The most studied procedure was organ transplantation(n=39),including 15 kidney,14 liver,5 heart,4 lung,and 1 intestinal.Arthroplasty(n=4),cataract surgery(n=2),bariatric surgery(n=1),mosaicplasty(n=1),and septoplasty(n=1)completed the surgical interventions included.Thirty-nine of the models used were theoretical(the most frequently applied being the Markov model,n=34),and nine were real-life.The survey used to measure quality of life in 11 articles was the European Quality of Life-5 dimensions,but in 32 articles the survey was not specified.The willingness-to-pay per QALY gained ranged from$100000 in the United States to€20000 in Spain.CONCLUSION The relationship between QALYs and SWLs has only rarely been studied in the literature.The rate of QALYs lost on SWLs has not been determined.Future research is warranted to address this issue.展开更多
BACKGROUND The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years.Therefore,the population that is≥50 years in age requires l...BACKGROUND The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years.Therefore,the population that is≥50 years in age requires long-term and regular colonoscopies.Uncomfortable bowel preparation is the main reason preventing patients from undergoing regular colonoscopies.The standard bowel preparation regimen of 4-L polyethylene glycol(PEG)is effective but poorly tolerated.AIM To investigate an effective and comfortable bowel preparation regimen for hospitalized patients≥50 years in age.METHODS Patients were randomly assigned to group 1(2-L PEG+30-mL lactulose+a lowresidue diet)or group 2(4-L PEG).Adequate bowel preparation was defined as a Boston bowel preparation scale(BBPS)score of≥6,with a score of≥2 for each segment.Non-inferiority was prespecified with a margin of 10%.Additionally,the degree of comfort was assessed based on the comfort questionnaire.RESULTS The proportion of patients with a BBPS score of≥6 in group 1 was not significantly different from that in group 2,as demonstrated by intention-to-treat(91.2%vs 91.0%,P=0.953)and per-protocol(91.8%vs 91.0%,P=0.802)analyses.Furthermore,in patients≥75 years in age,the proportion of BBPS scores of≥6 in group 1 was not significantly different from that in group 2(90.9%vs 97.0%,P=0.716).Group 1 had higher comfort scores(8.85±1.162 vs 7.59±1.735,P<0.001),longer sleep duration(6.86±1.204 h vs 5.80±1.730 h,P<0.001),and fewer awakenings(1.42±1.183 vs 2.04±1.835,P=0.026)than group 2.CONCLUSION For hospitalized patients≥50 years in age,the bowel preparation regimen comprising 2-L PEG+30-mL lactulose+a low-residue diet produced a cleanse that was as effective as the 4-L PEG regimen and even provided better comfort.展开更多
基金financially supported by Western Young Scholar Program-B of Chinese Academy of Sciences(No.2018-XBQNXZ-B-020)China Postdoctoral Science Foundation(No.2019M663864)+2 种基金National Natural Science Grants of China(No.41803024)Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA20020101)Open Fund of State Key Laboratory of Loess and Quaternary Geology(No.SKLLQG2011)。
文摘A pollen study was conducted on an alpine marsh sediment in the Son Kul Basin and was allowed to reconstruct changes in vegetation dynamics and climatic information in the western Tianshan Mountains during the past 2000 years.Pollen diagram reveals that regional vegetation is dominated by alpine meadow in the past 2000 years,being similar with modern vegetation components in the basin.The Artemisia/Chenopodiaceae-indicated moisture exhibits a warm-dry Roman Warm Period(RWP,~0-~500 AD),a cold-dry Dark Ages Cold Period(DACP,~500-~800 AD),a warm-wet Medieval Warm Period(MWP,~800-~1350 AD),a cold-dry Little Ice Age(LIA,~1350-~1850 AD)and a warm-dry Current Warm Period(CWP,since~1850 AD).Our pollen-based moisture reconstructions are supported by other nearby moisture records.Combined with other pollen data in the western Tianshan Mountains,we found that the vegetation was relatively stable before~1650-~1750 AD and the anthropogenic activities obviously intensified afterwards(especially at the middle-elevation sites).Further work involving more and higher-resolution palaeovegetation records would contribute to fully understand the information on the complex links between environmental,climatic and anthropogenic changes in the western Tianshan Mountains.
文摘The Fourth Assessment Report of IPCC(IPCC AR4)concluded that average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than that of any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years.However,after evaluating Global or Northern Hemisphere temperature change series derived from ice cores,tree rings,
基金This research was financially supported by Western Young Scholar Program-B of Chinese Academy of Sciences(No.2018-XBQNXZ-B-020)National Natural Science Foundation of China(Grant Nos.41771234 and 41803024)Open Fund of State Key Laboratory of Loess and Quaternary Geology(No.SKLLQG2011).
文摘Over the past 2000 years,a high-resolution pollen record from the Yushenkule Peat(46°45′-46°57′N,90°46′-90°61′E,2374 m a.s.l.)in the south-eastern Altai Mountains of northwestern China has been used to explore the changes in vegetation and climate.The regional vegetation has been dominated by alpine meadows revealed from pollen diagrams over the past 2000 years.The pollen-based climate was warm and wet during the Roman Warm Period(0-520 AD),cold and wet during the Dark Age Cold Period(520-900 AD),warm and wet during the Medieval Warm Period(900-1300 AD),and cold and dry during the Little Ice Age(1300-1850 AD).Combined with other pollen data from the Altai Mountains,we found that the percentage of arboreal pollen showed a reduced trend along the NW-SE gradient with decreasing moisture and increasing climatic continentality of the Altai Mountains over the past 2000 years;this is consistent with modern distributions of taiga forests.We also found that the taiga(Pinus forest)have spread slightly,while the steppe(Artemisia,Poaceae and Chenopodiaceae)have recovered significantly in the Altai Mountains over the past 2000 years.In addition,the relatively warm-wet climate may promote high grassland productivity and southward expansion of steppe,which favors the formation of Mongol political and military power.
文摘工程人员常通过对比设计软件与有限元软件的分析结果,以验算和校核结构设计的合理性。然而,由于软件分析内核的差异,设计软件与有限元软件之间的模型信息往往难以直接传递并转化。针对SAP2000结构设计分析软件向ANSYS有限元分析软件的模型转化问题,基于Python语言和APDL参数化设计语言,编译并开发了STAMT V1.0(SAP2000 To ANSYS Model Transformation V1.0)模型转化程序。相比已有转化程序,STAMT程序实现了更多单元类型、材料属性、截面类型、荷载形式的转化,提高了模型转化的通用性。其次,其涵盖了节点坐标系变换、梁单元坐标系变换、梁端自由度释放、创建刚性域等必备功能,进一步满足了模型转化过程中的功能性需求。然后,采用先建立几何模型后生成有限元模型的转化思路,实现了梁单元网格数量的自定义以及板壳荷载向梁的传递,软件操作界面简洁,便于工程人员的使用。最后,通过单层工业厂房和多层框架结构的两个算例分析,得到转化后模型的质量与原模型一致,前5阶周期的平均误差不超过3%,满足精度要求。研究分析验证了STAMT程序可实现SAP2000模型向ANSYS模型的准确、快速转化。
基金supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-Q1-01)China Global Change Research Program (Grant No. 2010CB950101)+1 种基金National Natural Science Foundation of China (Grant No. 40625002)the IGSNRR Research Foundation (Grant No. 200905006)
文摘Using 24 proxy temperature series,the rates of temperature change in China are analyzed at the 30-to 100-year scales for the past 2000 years and at the 10-year scale for the past 500 years.The results show that,at the 100-year scale,the warming rate for the whole of China in the 20th century was only 0.6±1.6°C/100 a (interval at the 95% confidence level,which is used hereafter),while the peak warming rate for the period from the Little Ice Age (LIA) to the 20th century reached 1.1±1.2°C/100 a,which was the greatest in the past 500 years and probably the past 2000 years.At the 30-year scale,warming in the 20th century was quite notable,but the peak rate was still less than rates for previous periods,such as the rapid warming from the LIA to the 20th century and from the 270s-290s to 300s-320s.At the 10-year scale,the warming in the late 20th century was very evident,but it might not be unusual in the context of warming over the past 500 years.The exact timing,duration and magnitude of the warming peaks varied from region to region at all scales.The peak rates of the 100-year scale warming in the AD 180s-350s in northeastern China as well as those in the 260s-410s and 500s-660s in Tibet were all greater than those from the mid-19th to 20th century.Meanwhile,the rates of the most rapid cooling at scales of 30 to 100 years in the LIA were prominent,but they were also not unprecedented in the last 2000 years.At the 10-year scale,for the whole of China,the most rapid decadal cooling in the 20th century was from the 1940s to 1950s with a rate of 0.3±0.6°C/10 a,which was similar to rates for periods before the 20th century.For all regions,the rates of most rapid cooling in the 20th century were all less than those for previous periods.
基金supported by grants to IGSNRR from China Global Change Research Program of MOST (Grant No. 2010CB950101)the Chinese Academy of Sciences (Grant No. XDA05080100)National Natural Science Foundation of China (Grant No. 41071029)
文摘The general characteristics of climate changes over the past 2000 years in China,regional differences and uncertainties were analyzed based on the recently peer-reviewed high time-resolution climatic reconstructions.The results showed that there exists four warm periods of the temperature variation in China since the Qin Dynasty,including the western and eastern Han Dynasties(200 BC-AD 180),the Sui and Tang dynasties(541-810),the Song and Yuan dynasties(931-1320),and the 20th century,and three cold phases involving the Wei,Jin,and North-South Dynasties(181-540),the late Tang Dynasty(811-930),and the Ming and Qing dynasties(1321-1920).The Song and Yuan warm period is consistent with the Medieval Warm Period over the Northern Hemisphere,and the cold phases of the North-South Dynasties and the Ming and Qing dynasties are paralleled to the Dark Ages Cold Period and the Little Ice Age,respectively.The 13th-15th century could be a shift to the wet condition of the climate,and the low precipitation variability is exhibited in western China prior to 1500.In the context of the climate warming,the pattern of the drought in north and flood in south is prevalent over the eastern China.In addition,the published reconstructions have a high level of confidence for the past 500 years,but large uncertainties exist prior to the 16th century.
文摘随着经济发展与城镇化快速推进,中国居民膳食模式发生显著转变,并产生了严重的资源环境后果。为识别城乡居民食物消费碳-水足迹的关键驱动因素,缓解水资源消耗,助力双碳目标实现,该研究测算并对比分析了中国31(30)省市2000—2020年城乡居民人均食物消费碳-水足迹,通过对数平均迪式指数算法(logarithmic mean index method,LMDI)对碳-水足迹进行了驱动因素分解。结果显示:2000—2020年中国城镇人均食物消费碳足迹(水足迹)增加了29.63%(32.94%),农村碳足迹(水足迹)增加了4.59%(7.91%)。从空间演变来看,城镇人均食物消费碳-水足迹较高的地区由沿海省份逐渐扩散至内陆,而农村呈南北高-中间低的分布格局。从驱动因素来看,经济水平是城乡居民食物消费碳-水足迹增加的主要动因,且消费水平表现为抑制作用;人口城镇化驱动城镇居民食物消费碳-水足迹增加,而在农村起到抑制作用。该研究从促进食物消费结构转型,多渠道拓宽食物来源等方面提出建议,旨在促进中国城乡居民食物可持续消费。
基金Supported by the Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-Q1-01, XDA05080100)National Basic Research and Development (973) Program of China (2010CB950100)+1 种基金National Science and Technology Support Program of China (2007BAC03A01)National Natural Science Foundation of China (41071029)
文摘The spatial patterns of precipitation anomalies during five 30-yr warm periods of 691-720, 1231-1260, 1741-1770, 1921-1950, and 1981-2000 were investigated using a dryness/wetness grading dataset covering 48 stations from Chinese historical documents and 22 precipitation proxy series from natural archives. It was found that the North China Plain (approximately 35 -40 N, east of 105 E) was dry in four warm periods within the centennial warm epochs of 600-750, the Medieval Warm Period (about 900-1300) and after 1900. A wet condition prevailed over most of China during 1741-1770, a 30-yr warm peak that occurred during the Little Ice Age (about 1650-1850). The spatial pattern of the precipitation anomaly in 1981-2000 over East China (25 -40 N, east of 105 E) is roughly consistent with that in 1231-1260, but a difference in the precipitation anomaly appeared over the Tibetan Plateau. The spatial patterns of the precipitation anomalies over China varied between all five 30-yr warm periods, which implies that the matching pattern between temperature and precipitation change is multiform, and the precipitation anomaly could be positive or negative when a decadal warm climate occurs in different climate epochs. This result may provide a primary reference for the mechanism detection and climate simulation of the precipitation anomaly of the future warm climate.
文摘Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to 2021.It also aimed to recommend targeted interventions for the prevention and treatment of HIV/AIDS in elderly patients.Methods Data on newly reported cases of PLWHA,aged≥50 years in China from 2018 to 2021,were collected using the CRIMS.Trend tests and spatial analyses were also conducted.Results Between 2018 and 2021,237,724 HIV/AIDS cases were reported among patients aged≥50 years in China.The main transmission route was heterosexual transmission(91.24%).Commercial heterosexual transmission(CHC)was the primary mode of transmission among males,while non-marital non-CHC([NMNCHC];60.59%)was the prevalent route in women.The proportion of patients with CHC decreased over time(Z=67.716,P<0.01),while that of patients with NMNCHC increased(Z=153.05,P<0.01).The sex ratio varied among the different modes of infection,and it peaked at 17.65 for CHC.The spatial analysis indicated spatial clustering,and the high-high clustering areas were mainly distributed in the southwestern and central-southern provinces.Conclusion In China,PLWHA,aged≥50 years,were predominantly infected through heterosexual transmission.The primary modes of infection were CHC and NMNCHC.There were variations in the sex ratio among different age groups,infected through various sexual behaviors.HIV/AIDS cases exhibited spatial clustering.Based on these results,the expansion of HIV testing,treatment,and integrated behavioral interventions in high-risk populations is recommended to enhance disease detection in key regions.
文摘The objectives of this work were to evaluate the surgical activities carried out in the general surgery department of the Reference Health Center of Commune I of Bamako, to describe the sociodemographic characteristics of the operated patients, to determine the main pathologies encountered and to evaluate qualitatively the result of the treatment. In order to improve performance, and the quality of care, and to identify common pathologies in the surgical department, we undertook a retrospective study on surgical activities from January 2009 to December 2010. At the end of this study, out of 474 men and 187 women (equal sex ratio 2.53);we were able to determine the frequency of surgical pathologies. Farmers, housewives and pupils/students were the most represented with 25.9% respectively;20% and 13.3%. The most frequently observed pathologies were wall hernia (44.8%), prostate adenoma (12%) and acute appendicitis (10.5%). The average length of hospitalization was 3.43 days. Infectious complications affected 25 patients (3.8% of cases) and a death rate of 0.45% (i.e. 3 patients). The average cost of care was 53,500 FCFA. Indeed, the reality of surgical practice in health centers was not the same because of the level of skills of practicing surgeons.
文摘BACKGROUND The quality-adjusted life year(QALY)is a metric that is increasingly used today in the field of health economics to evaluate the value of different medical treatments and procedures.Surgical waiting lists(SWLs)represent a pressing problem in public healthcare.The QALY measure has rarely been used in the context of surgery.It would be interesting to know how many QALYs are lost by patients on SWLs.AIM To investigate the relationship between QALYs and SWLs in a systematic review of the scientific literature.METHODS The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement.An unlimited search was carried out in PubMed,updated on January 19,2024.Data on the following variables were investigated and analyzed:Specialty,country of study,procedure under study,scale used to measure QALYs,the use of a theoretical or real-life model,objectives of the study and items measured,the economic value assigned to the QALY in the country in question,and the results and conclusions published.RESULTS Forty-eight articles were selected for the study.No data were found regarding QALYs lost on SWLs.The specialties in which QALYs were studied the most in relation to the waiting list were urology and general surgery,with 15 articles each.The country in which the most studies of QALYs were carried out was the United States(n=21),followed by the United Kingdom(n=9)and Canada(n=7).The most studied procedure was organ transplantation(n=39),including 15 kidney,14 liver,5 heart,4 lung,and 1 intestinal.Arthroplasty(n=4),cataract surgery(n=2),bariatric surgery(n=1),mosaicplasty(n=1),and septoplasty(n=1)completed the surgical interventions included.Thirty-nine of the models used were theoretical(the most frequently applied being the Markov model,n=34),and nine were real-life.The survey used to measure quality of life in 11 articles was the European Quality of Life-5 dimensions,but in 32 articles the survey was not specified.The willingness-to-pay per QALY gained ranged from$100000 in the United States to€20000 in Spain.CONCLUSION The relationship between QALYs and SWLs has only rarely been studied in the literature.The rate of QALYs lost on SWLs has not been determined.Future research is warranted to address this issue.
基金The study was approved by the Ethics Committee of Beijing Tongren Hospital Affiliated to Capital Medical University(Approval No.TRECKY2021-227).
文摘BACKGROUND The incidence and mortality rate of colorectal cancer progressively increase with age and become particularly prominent after the age of 50 years.Therefore,the population that is≥50 years in age requires long-term and regular colonoscopies.Uncomfortable bowel preparation is the main reason preventing patients from undergoing regular colonoscopies.The standard bowel preparation regimen of 4-L polyethylene glycol(PEG)is effective but poorly tolerated.AIM To investigate an effective and comfortable bowel preparation regimen for hospitalized patients≥50 years in age.METHODS Patients were randomly assigned to group 1(2-L PEG+30-mL lactulose+a lowresidue diet)or group 2(4-L PEG).Adequate bowel preparation was defined as a Boston bowel preparation scale(BBPS)score of≥6,with a score of≥2 for each segment.Non-inferiority was prespecified with a margin of 10%.Additionally,the degree of comfort was assessed based on the comfort questionnaire.RESULTS The proportion of patients with a BBPS score of≥6 in group 1 was not significantly different from that in group 2,as demonstrated by intention-to-treat(91.2%vs 91.0%,P=0.953)and per-protocol(91.8%vs 91.0%,P=0.802)analyses.Furthermore,in patients≥75 years in age,the proportion of BBPS scores of≥6 in group 1 was not significantly different from that in group 2(90.9%vs 97.0%,P=0.716).Group 1 had higher comfort scores(8.85±1.162 vs 7.59±1.735,P<0.001),longer sleep duration(6.86±1.204 h vs 5.80±1.730 h,P<0.001),and fewer awakenings(1.42±1.183 vs 2.04±1.835,P=0.026)than group 2.CONCLUSION For hospitalized patients≥50 years in age,the bowel preparation regimen comprising 2-L PEG+30-mL lactulose+a low-residue diet produced a cleanse that was as effective as the 4-L PEG regimen and even provided better comfort.
