Objective: Liver cancer is one of the most common cancers and major cause of cancer deaths in China,which accounts for over 50% of new cases and deaths worldwide.The systematic liver cancer statistics including of pro...Objective: Liver cancer is one of the most common cancers and major cause of cancer deaths in China,which accounts for over 50% of new cases and deaths worldwide.The systematic liver cancer statistics including of projection through 2030 could provide valuable information for prevention and control strategies in China,and experience for other countries.Methods: The burden of liver cancer in China in 2014 was estimated using 339 cancer registries’ data selected from Chinese National Cancer Center(NCC).Incident cases of 22 cancer registries were applied for temporal trends from 2000 to 2014.The burden of liver cancer through 2030 was projected using age-period-cohort model.Results: About 364,800 new cases of liver cancer(268,900 males and 95,900 females) occurred in China,and about 318,800 liver cancer deaths(233,500 males and 85,300 females) in 2014.Western regions of China had the highest incidence and mortality rates.Incidence and mortality rates decreased by about 2.3% and 2.6% per year during the period of 2000-2014,respectively,and would decrease by more than 44% between 2014 and 2030 in China.The young generation,particularly for those aged under 40 years,showed a faster down trend.Conclusions: Based on the analysis,incidence and mortality rates of liver cancer are expected to decrease through 2030,but the burden of liver cancer is still serious in China,especially in rural and western areas.Most cases of liver cancer in China can be prevented through vaccination and more prevention efforts should be focused on high risk groups.展开更多
The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of ...The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of precipitation,so that the two relevant parameters can represent the annual distribution of total precipitation correctly and indeed accurately.The relationship between the spatial and temporal distribution patterns and variations of the two parameters and the annual precipitation amount in China has been further investigated.Results demonstrate that the precipitation-concentration degree and the precipitation-concentration period increase from southeast to northwest gradually.Moreover there obviously exists a belt pattern:the largest variability of the precipitation-concentration degree and the precipitation-concentration period occurs in the Yellow River Valley and the middle and lower reaches of the Yangtze River, corresponding to the significant zones in which flood and drought take place frequently.It is found that there exist high correlations between the precipitation-concentration degree and precipitation- concentration period and the annual precipitation amount in Northeast China,North China,the middle and lower reaches of the Yangtze River. Furthermore,8-year and 22-year periodic oscillations in the precipitation-concentration degree and 6-year and 12-year cycles in the precipitation-concentration period are identified by use of their Morlet wavelet analysis.展开更多
Objective:Breast cancer was the most common cancer and the fifth cause of cancer deaths among women in China in 2015.The evaluation of the long-term incidence and mortality trends and the prediction of the future burd...Objective:Breast cancer was the most common cancer and the fifth cause of cancer deaths among women in China in 2015.The evaluation of the long-term incidence and mortality trends and the prediction of the future burden of breast cancer could provide valuable information for developing prevention and control strategies.Methods:The burden of breast cancer in China in 2015 was estimated by using qualified data from 368 cancer registries from the National Central Cancer Registry.Incident cases and deaths in 22 cancer registries were used to assess the time trends from 2000 to 2015.A Bayesian age-period-cohort model was used to project the burden of breast cancer to 2030.Results:Approximately 303,600 new cases of breast cancer(205,100 from urban areas and 98,500 from rural areas)and 70,400 breast cancer deaths(45,100 from urban areas and 24,500 from rural areas)occurred in China in 2015.Urban regions of China had the highest incidence and mortality rates.The most common histological subtype of breast cancer was invasive ductal carcinoma,followed by invasive lobular carcinoma.The age-standardized incidence and mortality rates increased by 3.3%and 1.0%per year during 2000–2015,and were projected to increase by more than 11%until 2030.Changes in risk and demographic factors between 2015 and 2030 in cases are predicted to increase by approximately 13.3%and 22.9%,whereas deaths are predicted to increase by 13.1%and 40.9%,respectively.Conclusions:The incidence and mortality of breast cancer continue to increase in China.There are no signs that this trend will stop by 2030,particularly in rural areas.Effective breast cancer prevention strategies are therefore urgently needed in China.展开更多
Supported by MSS images in the mid and late 1970s,TM images in the early 1990s and TM/ETM images in 2004,grassland degradation in the＂Three-River Headwaters＂region （TRH region）was interpreted through analysis on R...Supported by MSS images in the mid and late 1970s,TM images in the early 1990s and TM/ETM images in 2004,grassland degradation in the＂Three-River Headwaters＂region （TRH region）was interpreted through analysis on RS images in two time series,then the spatial and temporal characteristics of grassland degradation in the TRH region were analyzed since the 1970s.The results showed that grassland degradation in the TRH region was a continuous change process which had large affected area and long time scale,and rapidly strengthen phenomenon did not exist in the 1990s as a whole.Grassland degradation pattern in the TRH region took shape initially in the mid and late 1970s.Since the 1970s,this degradation process has taken place continuously,obviously characterizing different rules in different regions.In humid and semi-humid meadow region,grassland firstly fragmentized, then vegetation coverage decreased continuously,and finally＂black-soil-patch＂degraded grassland was formed.But in semi-arid and arid steppe region,the vegetation coverage decreased continuously,and finally desertification was formed.Because grassland degradation had obviously regional differences in the TRH region,it could be regionalized into 7 zones, and each zone had different characteristics in type,grade,scale and time process of grassland degradation.展开更多
Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regres...Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations （non-urban） and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime （13%/yr referred to 2006 level） was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds （VOC）-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.展开更多
Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and tempora...Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.展开更多
The agricultural and land policies in China are always focused on protecting its food supply and security because of the country＇s large population and improved diets. The crop production guide ＇Take Grain as the Ke...The agricultural and land policies in China are always focused on protecting its food supply and security because of the country＇s large population and improved diets. The crop production guide ＇Take Grain as the Key Link prompted peasants to plant grain on most of the agricultural land, leading to the majority of fertilizer being used in grain crops for many years in China. This situation has changed dramatically in recent years. Based on data pertaining to provincial crops sown area and fertilizer use per unit area in 1998 and 2008, the temporal and spatial variations of China＇s fertilizer consumption by crops were analyzed at the provincial level, and the results are presented here. （1） Fertilizer consumption in China grew strongly in the last decade, while the growth was mainly attributable to the increase of fertilizer consumption by horticultural crops. The fertilizer consumption of grain crops dropped from 71.0% in 1998 to 57.8% in 2008. Thus, it is concluded that the emphasis of fertilizer consumption is shifting toward horticultural crops. （2） There were marked differences in the growth rates of fertilizer consumption from the regional point of view. The national average growth rate of fertilizer consumption was 31.9% during 1998-2008. The western and northeastern parts of the country came close to the national average, while the eastern part was lower, with an average of 13.0%, and central China was much higher （50.8%）. The increase of fertilizer consumption in central and west China was higher than the other zones, which already accounted for 77.9% of the national total. Thus, it is concluded that the consumption emphasis of chemical fertilizer shifts toward the central and western regions. （3） The decline of fertilizer consumption by grain crops was largely due to the decrease in sown area compared with the increase by vegetable crops attributable to the enlarging sown area; the increase by orchard crops was affected by both expanding the sown area and fertilizer use per unit are展开更多
Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventi...Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested. Methods We used a dataset provided by the Chinese National Survey on Students’ Constitution and Health from 1985‐2010. Subjects were 7‐18‐year‐old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status. Results Increased rates of the epidemic （overweight and obesity combined） were greatest in large coastal cities‐32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty‐stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school‐aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals. Conclusion The prognosis for China＇s childhood‐obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.展开更多
Largely due to population ageing,the cancer burden from older people has been rising,which imposed considerable pressure on current Chinese healthcare system.We provide comprehensive information about cancer burden of...Largely due to population ageing,the cancer burden from older people has been rising,which imposed considerable pressure on current Chinese healthcare system.We provide comprehensive information about cancer burden of Chinese older people based on the most recent data from National Central Cancer Registry of China.The logarithmic linear regression was used to project the current cancer burden in 2022,and Joinpoint regression was used for temporal trend analysis from 2000 to 2017.We also estimated cancer statistics of older people in the US,Japan and the Republic of Korea for comparisons.It is estimated that 2.79 million cases and 1.94 million deaths occur for Chinese older people,representing 55.8%and 68.2%of cases and deaths in all population in 2022.The overall cancer incidence rate gradually increased among older women,while the mortality rates declined for both sexes.Notably,approximately 10.0%of all cases and 17.7%of all deaths are from people aged over 80 years,and cancer incidence and mortality in this age group showed upward trends for women.Lung cancer and digestive cancers are the leading cancer types for Chinese older people.Compared with other countries,China has lower incidence rates but higher mortality rates for older people.The rapidly growing burden of prostate cancer,breast cancer,colorectal cancer,and declines in esophageal cancer,stomach cancer,and liver cancer among older people indicate the cancer pattern in China is being in a transition stage to that in developed countries.Our findings imply that it should be the national health priority to meet the growing demands for cancer diagnosis,treatment and care services from the older people as the rapid population ageing in next few decades.展开更多
This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets...This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors.展开更多
The Haiyuan fault is a major seismogenic fault in north-central China where the 1920 Haiyuan earthquake of magnitude 8.5 occurred, resulting in more than 220000 deaths. The fault zone can be divided into three segment...The Haiyuan fault is a major seismogenic fault in north-central China where the 1920 Haiyuan earthquake of magnitude 8.5 occurred, resulting in more than 220000 deaths. The fault zone can be divided into three segments based on their geometric patterns and associated geomorphology. To study paleoseismology and recurrent history of devastating earthquakes along the fault, we dug 17 trenches along different segments of the fault zone. Although only 10 of them allow the paleoearthquake event to be dated, together with the 8 trenches dug previously they still provide adequate information that enables us to capture major paleoearthquakes oc- curring along the fault during the past geological time. We discovered 3 events along the eastern segment during the past 14000 a, 7 events along the middle segment during the past 9000 a, and 6 events along the western segment during the past 10000 a. These events clearly depict two temporal clusters. The first cluster occurs from 4600 to 6400 a, and the second occurs from 1000 to 2800 a, approximately. Each cluster lasts about 2000 a. Time period between these two clus- ters is also about 2000 a. Based on fault geometry, segmentation pattern, and paleoearthquake events along the Haiyuan fault we can identify three scales of earthquake rupture: rupture of one segment, cascade rupture of two segments, and cascade rupture of entire fault (three segments). Interactions of slip patches on the surface of the fault may cause rupture on one patch or ruptures of more than two to three patchs to form the complex patterns of cascade rupture events.展开更多
Daily maximum/minimum temperatures and relative humidity records from 510 stations in China for the period 1960–2008 were used to investigate geographical patterns and temporal variations of heatwave （HW） events. D...Daily maximum/minimum temperatures and relative humidity records from 510 stations in China for the period 1960–2008 were used to investigate geographical patterns and temporal variations of heatwave （HW） events. Dry and wet HW events were compared by different definitions. Regionally, both dry and wet HW events are commonly located in southeastern China in the monsoon area, with neither type occurring in the northeast part of Northeast China and Southwest China, while the north-northwest region of the country experiences dry HW events and a few wet HW events. In the southeast of the country, site dry HW events occurred from April to September and mostly in June, while site wet HW events occurred from April to October and mostly in September. In total, 163 regional wet HW events were identified. The ten longest regional wet HW events lasted for more than 20 days, while the mean duration for 163 events was about 11 days. For the top ten events, six occurred after the 1990s, compared with four before this time. Global surface warming was clear since 1979, but the frequency and severity of regional wet HW events were relatively low in the 1980s, increasing remarkably since the 1990s. Possible reasons for this might be the strong interdecadal and interannual variations in regional atmospheric circulations, as well as water transport related directly to temperature contrasts in different regions, rather than global-mean temperature changes.展开更多
Net primary productivity （NPP） is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study ...Net primary productivity （NPP） is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study the process-based Boreal Ecosystem Productivity Simulator （BEPS） was employed to study the changes of NPP in China＇s ecosystems for the period from 2000 to 2010. The BEPS model was first validated using gross primary productivity （GPP） measured at typical flux sites and forest NPP measured at different regions. Then it was driven with leaf area index （LAI） inversed from the Moderate Resolution Imaging Spectroradiometer （MODIS） reflec- tance and land cover products and meteorological data interpolated from observations at753 national basic meteorological stations to simulate NPP at daily time steps and a spatial resolution of 500m from January 1, 2000 to December 31, 2010. Validations show that BEPS is able to capture the seasonal variations of tower-based GPP and the spatial variability of forest NPP in different regions of China. Estimated national total of annual NPP varied from 2.63 to 2.84Pg C.yr-1, averaging 2.74Pg C.yr-1 during the study period. Simulated terrestrial NPP shows spatial patterns decreasing from the east to the west and from the south to the north, in association with land cover types and climate. South-west China makes the largest contribution to the national total of NPP while NPP in the North-west account for only 3.97% of the national total. During the recent 11 years, the temporal changes of NPP were heterogamous. NPP increased in 63.8% of China＇s landmass, mainly in areas north of the Yangtze River and decreased in most areas of southern China, owing to the low temperature freezing in early 2008 and the severe drought in late 2009.展开更多
From studies undertaken during 1995-2004, annual budgets of CH4 emissions from natural wetlands and its temporal and spatial variations were examined throughout China, and various factors influencing CH4 emissions wer...From studies undertaken during 1995-2004, annual budgets of CH4 emissions from natural wetlands and its temporal and spatial variations were examined throughout China, and various factors influencing CH4 emissions were also evaluated. The seasonal variation in CH4 emissions that increased with increasing plant growth reached its peak in August; decrease in the emissions was found in freshwater marshes but not in peatlands. Emissions were mainly controlled by temperature and depth of standing water. Low CH4 emissions at the early plant growing stages were not because of deficiency of organic C for CH4 production but because of low temperatures. Low temperatures not only reduced CH4 production but also stimulated CH4 oxidation by lowering the activity of other aerobic microbes which left more 02 in the rhizosphere for methanotrophs. Low summer temperatures （below 20 ℃） in the Qinghai-Tibetan Plateau lowered CH4 production and CH4 emission resulting in little or no seasonal variation of emissions. Diel and spatial variation in CH4 emissions depended on plant species. For plants that transport CH4 using the pressure-driven convective through-flow mechanism, diel variation in CH4 emissions was governed by diel variation of solar energy load （that produces temperature and vapor pressure differences within various plant tissues） and stomatal conductance. For plants that transport gases using the molecular diffusion mechanism only, the diel variation of CH4 emissions was because of differences in the magnitude of O2 produced through photosynthesis and then delivered into the rhizomes and/or rhizosphere for CH4 oxidation. Emergent plants could transport more CH4 than submerged plants because the former transport CH4 directly into the atmosphere rather than into water as do submerged plants where CH4 can be further be oxidized during its diffusion from water to the atmosphere. Emergent plants with high gas transport capacity could not only transport more CH4 into the atmosphere but also live in deeper water, whic展开更多
Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective preventio...Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective prevention strategies.Methods:The data on incidence,mortality,and disability-adjusted life-years(DALYs)of GC in China from1990 to 2019 were obtained from the Global Burden of Disease Study(2019).The estimated annual percentage change(EAPC)was calculated to evaluate the temporal trends of disease burden of GC,and the package Nordpred in the R program was used to perform an age-period-cohort analysis to predict the numbers and rates of incidence and mortality in the next 25 years.Results:The number of incident cases of GC increased from 317.34 thousand in 1990 to 612.82 thousand in2019,while the age-standardized incidence rate(ASIR)of GC decreased from 37.56 per 100,000 in 1990 to 30.64 per 100,000 in 2019,with an EAPC of-0.41[95%confidence interval(95%CI):-0.77,-0.06].Pronounced temporal trends in mortality and DALYs of GC were observed.In the next 25 years,the numbers of new GC cases and deaths are expected to increase to 738.79 thousand and 454.80 thousand,respectively,while the rates of incidence and deaths should steadily decrease.The deaths and DALYs attributable to smoking were different for males and females.Conclusions:In China,despite the fact that the rates of GC have decreased during the past three decades,the numbers of new GC cases and deaths increased,and will continue to increase in the next 25 years.Additional strategies are needed to reduce the burden of GC,such as screening and early detection,novel treatments,and the prevention of risk factors.展开更多
Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by...Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by external factors, like agricultural policies. Since 2004, seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China. So far, few studies have investigated the effects of these policies on the rice cropping systems. In this study, based upon the long-term field survey information on paddy rice fields, we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region （PLR）, China. The results revealed that： （1） from 2004 to 2010, the decrement of paddy rice field was 46.76 km2 due to the land use change. （2） The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields. NDVI curves of single cropping rice fields showed one peak, while NDVI curves of double cropping rice fields displayed two peaks annually. NDVI of fallow field fluctuated between 0.15 and 0.40. NDVI of the flooded field during the transplanting period was relatively low, about 0.20±0.05, while NDVI during the period of panicle initiation to heading reached the highest level （above 0.80）. Then, several temporal windows were determined based upon the NDVI variations of different rice cropping systems. （3） With the spatial pattern of paddy rice field and the NDVI threshold within optimum temporal windows, the spatial variation of rice cropping systems was very obvious, with an increased multiple cropping index of rice about 20.2% from 2004 to 2010. The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR, China.展开更多
基金supported by National Natural Science Foundation of China(No.81602931)Ministry of Science and Technology(No.2014FY121100)State Key Projects Specialized on Infectious Diseases(No.2012ZX10002008)
文摘Objective: Liver cancer is one of the most common cancers and major cause of cancer deaths in China,which accounts for over 50% of new cases and deaths worldwide.The systematic liver cancer statistics including of projection through 2030 could provide valuable information for prevention and control strategies in China,and experience for other countries.Methods: The burden of liver cancer in China in 2014 was estimated using 339 cancer registries’ data selected from Chinese National Cancer Center(NCC).Incident cases of 22 cancer registries were applied for temporal trends from 2000 to 2014.The burden of liver cancer through 2030 was projected using age-period-cohort model.Results: About 364,800 new cases of liver cancer(268,900 males and 95,900 females) occurred in China,and about 318,800 liver cancer deaths(233,500 males and 85,300 females) in 2014.Western regions of China had the highest incidence and mortality rates.Incidence and mortality rates decreased by about 2.3% and 2.6% per year during the period of 2000-2014,respectively,and would decrease by more than 44% between 2014 and 2030 in China.The young generation,particularly for those aged under 40 years,showed a faster down trend.Conclusions: Based on the analysis,incidence and mortality rates of liver cancer are expected to decrease through 2030,but the burden of liver cancer is still serious in China,especially in rural and western areas.Most cases of liver cancer in China can be prevented through vaccination and more prevention efforts should be focused on high risk groups.
基金the National Natural Science Foundation of China projects"Studies on interaction between the South Asia high and the Asian monsoon and its mechanisms"(40175021)"Interannual and interdecadal variations of Meiyu in the Yangtze-Huaihe River Basins and their mechanisms"(40233037)
文摘The hierarchy and definition of the precipitation-concentration degree and precipitation- concentration period of annual precipitation have been proposed by using the so-called vector method of annual distribution of precipitation,so that the two relevant parameters can represent the annual distribution of total precipitation correctly and indeed accurately.The relationship between the spatial and temporal distribution patterns and variations of the two parameters and the annual precipitation amount in China has been further investigated.Results demonstrate that the precipitation-concentration degree and the precipitation-concentration period increase from southeast to northwest gradually.Moreover there obviously exists a belt pattern:the largest variability of the precipitation-concentration degree and the precipitation-concentration period occurs in the Yellow River Valley and the middle and lower reaches of the Yangtze River, corresponding to the significant zones in which flood and drought take place frequently.It is found that there exist high correlations between the precipitation-concentration degree and precipitation- concentration period and the annual precipitation amount in Northeast China,North China,the middle and lower reaches of the Yangtze River. Furthermore,8-year and 22-year periodic oscillations in the precipitation-concentration degree and 6-year and 12-year cycles in the precipitation-concentration period are identified by use of their Morlet wavelet analysis.
基金supported by grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(CIFMS,Grant No.2018-I2M-3-003)the National Key Research and Development Program of China(Grant No.2018YFC1315305)。
文摘Objective:Breast cancer was the most common cancer and the fifth cause of cancer deaths among women in China in 2015.The evaluation of the long-term incidence and mortality trends and the prediction of the future burden of breast cancer could provide valuable information for developing prevention and control strategies.Methods:The burden of breast cancer in China in 2015 was estimated by using qualified data from 368 cancer registries from the National Central Cancer Registry.Incident cases and deaths in 22 cancer registries were used to assess the time trends from 2000 to 2015.A Bayesian age-period-cohort model was used to project the burden of breast cancer to 2030.Results:Approximately 303,600 new cases of breast cancer(205,100 from urban areas and 98,500 from rural areas)and 70,400 breast cancer deaths(45,100 from urban areas and 24,500 from rural areas)occurred in China in 2015.Urban regions of China had the highest incidence and mortality rates.The most common histological subtype of breast cancer was invasive ductal carcinoma,followed by invasive lobular carcinoma.The age-standardized incidence and mortality rates increased by 3.3%and 1.0%per year during 2000–2015,and were projected to increase by more than 11%until 2030.Changes in risk and demographic factors between 2015 and 2030 in cases are predicted to increase by approximately 13.3%and 22.9%,whereas deaths are predicted to increase by 13.1%and 40.9%,respectively.Conclusions:The incidence and mortality of breast cancer continue to increase in China.There are no signs that this trend will stop by 2030,particularly in rural areas.Effective breast cancer prevention strategies are therefore urgently needed in China.
基金CAS Action-plan for West Development,No.KZCX2-XB2-06-03National Key Project of Scientific andTechnical Supporting Programs,No.2006BAC08B00
文摘Supported by MSS images in the mid and late 1970s,TM images in the early 1990s and TM/ETM images in 2004,grassland degradation in the＂Three-River Headwaters＂region （TRH region）was interpreted through analysis on RS images in two time series,then the spatial and temporal characteristics of grassland degradation in the TRH region were analyzed since the 1970s.The results showed that grassland degradation in the TRH region was a continuous change process which had large affected area and long time scale,and rapidly strengthen phenomenon did not exist in the 1990s as a whole.Grassland degradation pattern in the TRH region took shape initially in the mid and late 1970s.Since the 1970s,this degradation process has taken place continuously,obviously characterizing different rules in different regions.In humid and semi-humid meadow region,grassland firstly fragmentized, then vegetation coverage decreased continuously,and finally＂black-soil-patch＂degraded grassland was formed.But in semi-arid and arid steppe region,the vegetation coverage decreased continuously,and finally desertification was formed.Because grassland degradation had obviously regional differences in the TRH region,it could be regionalized into 7 zones, and each zone had different characteristics in type,grade,scale and time process of grassland degradation.
基金supported by the National Natural Science Foundation of China(No.21190052,41121004)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB05010500)+1 种基金the National Public Benefit Special Fund for Environmental Protection Research(No.201009001-4)the Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.13Z02ESPCP)
文摘Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations （non-urban） and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime （13%/yr referred to 2006 level） was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds （VOC）-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.
基金1Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-413).
文摘Nitrogen, phosphorus, and potassium balances for agroecosystems in China from 1993 to 2001 were calculated at national and provincial levels using statistical data and related parameters, and their spatial and temporal variabilities were analyzed with GIS to estimate the potential impacts of nutrient N, P and K surpluses or deficits to soil, water and air. At the national scale, the N and P balances from 1993 to 2001 showed a surplus, with the nitrogen surplus remaining relatively stable from 1997—2001. Although during this period the P surplus pattern was similar to N, it had smaller values and kept increasing as the use of phosphate fertilizer increased year by year. However, K was deficient from 1993 to 2001 even though from 1999 to 2001 the K deficit decreased. The spatial analysis revealed higher N surpluses in the more developed southeastern provinces and lowest in the western and northern provinces where there was less chemical fertilizer input. The serious K deficit mainly occurred in Shanghai and Beijing municipalities, Jiangsu, Zhejiang and Hubei provinces, and Xinjiang autonomous regions. For the years 1992, 1996 and 2001, N surpluses and K deficits had significant positive spatial correlations with per capita gross domestic product (GDP), per capita gross industrial output value, and per capita net income of rural households. This showed that the level of economic development played an important role on nutrient balances in the agroecosystems.
基金Foundation： National Natural Science Foundation of China, No. 40971062 National Basic Research Program of China, No.2010CB950902+1 种基金 National Natural Science Foundation of China, No.41101085 No.41171079
文摘The agricultural and land policies in China are always focused on protecting its food supply and security because of the country＇s large population and improved diets. The crop production guide ＇Take Grain as the Key Link prompted peasants to plant grain on most of the agricultural land, leading to the majority of fertilizer being used in grain crops for many years in China. This situation has changed dramatically in recent years. Based on data pertaining to provincial crops sown area and fertilizer use per unit area in 1998 and 2008, the temporal and spatial variations of China＇s fertilizer consumption by crops were analyzed at the provincial level, and the results are presented here. （1） Fertilizer consumption in China grew strongly in the last decade, while the growth was mainly attributable to the increase of fertilizer consumption by horticultural crops. The fertilizer consumption of grain crops dropped from 71.0% in 1998 to 57.8% in 2008. Thus, it is concluded that the emphasis of fertilizer consumption is shifting toward horticultural crops. （2） There were marked differences in the growth rates of fertilizer consumption from the regional point of view. The national average growth rate of fertilizer consumption was 31.9% during 1998-2008. The western and northeastern parts of the country came close to the national average, while the eastern part was lower, with an average of 13.0%, and central China was much higher （50.8%）. The increase of fertilizer consumption in central and west China was higher than the other zones, which already accounted for 77.9% of the national total. Thus, it is concluded that the consumption emphasis of chemical fertilizer shifts toward the central and western regions. （3） The decline of fertilizer consumption by grain crops was largely due to the decrease in sown area compared with the increase by vegetable crops attributable to the enlarging sown area; the increase by orchard crops was affected by both expanding the sown area and fertilizer use per unit are
文摘Objective To determine the extent of the obesity epidemic in school‐aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested. Methods We used a dataset provided by the Chinese National Survey on Students’ Constitution and Health from 1985‐2010. Subjects were 7‐18‐year‐old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status. Results Increased rates of the epidemic （overweight and obesity combined） were greatest in large coastal cities‐32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty‐stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school‐aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals. Conclusion The prognosis for China＇s childhood‐obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.
基金supported by the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-011,2021-12M-1-046)。
文摘Largely due to population ageing,the cancer burden from older people has been rising,which imposed considerable pressure on current Chinese healthcare system.We provide comprehensive information about cancer burden of Chinese older people based on the most recent data from National Central Cancer Registry of China.The logarithmic linear regression was used to project the current cancer burden in 2022,and Joinpoint regression was used for temporal trend analysis from 2000 to 2017.We also estimated cancer statistics of older people in the US,Japan and the Republic of Korea for comparisons.It is estimated that 2.79 million cases and 1.94 million deaths occur for Chinese older people,representing 55.8%and 68.2%of cases and deaths in all population in 2022.The overall cancer incidence rate gradually increased among older women,while the mortality rates declined for both sexes.Notably,approximately 10.0%of all cases and 17.7%of all deaths are from people aged over 80 years,and cancer incidence and mortality in this age group showed upward trends for women.Lung cancer and digestive cancers are the leading cancer types for Chinese older people.Compared with other countries,China has lower incidence rates but higher mortality rates for older people.The rapidly growing burden of prostate cancer,breast cancer,colorectal cancer,and declines in esophageal cancer,stomach cancer,and liver cancer among older people indicate the cancer pattern in China is being in a transition stage to that in developed countries.Our findings imply that it should be the national health priority to meet the growing demands for cancer diagnosis,treatment and care services from the older people as the rapid population ageing in next few decades.
基金Under the auspices of National Basic Research Program of China (No. 2010CB950900)National Natural Science Foundation of China (No. 40971223)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-EW-306)
文摘This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors.
基金supported by National Key Bas ic Research Program(Grant No.G1998040701)Joint Foundation of Earthquake Sciences(Grant No.95087421).
文摘The Haiyuan fault is a major seismogenic fault in north-central China where the 1920 Haiyuan earthquake of magnitude 8.5 occurred, resulting in more than 220000 deaths. The fault zone can be divided into three segments based on their geometric patterns and associated geomorphology. To study paleoseismology and recurrent history of devastating earthquakes along the fault, we dug 17 trenches along different segments of the fault zone. Although only 10 of them allow the paleoearthquake event to be dated, together with the 8 trenches dug previously they still provide adequate information that enables us to capture major paleoearthquakes oc- curring along the fault during the past geological time. We discovered 3 events along the eastern segment during the past 14000 a, 7 events along the middle segment during the past 9000 a, and 6 events along the western segment during the past 10000 a. These events clearly depict two temporal clusters. The first cluster occurs from 4600 to 6400 a, and the second occurs from 1000 to 2800 a, approximately. Each cluster lasts about 2000 a. Time period between these two clus- ters is also about 2000 a. Based on fault geometry, segmentation pattern, and paleoearthquake events along the Haiyuan fault we can identify three scales of earthquake rupture: rupture of one segment, cascade rupture of two segments, and cascade rupture of entire fault (three segments). Interactions of slip patches on the surface of the fault may cause rupture on one patch or ruptures of more than two to three patchs to form the complex patterns of cascade rupture events.
基金supported jointly by the National Natural Science Foundation of China (Grant No.40975039),GYHY201006018the Key Technologies R&D Program (Grant No. 2009BAC51B00)
文摘Daily maximum/minimum temperatures and relative humidity records from 510 stations in China for the period 1960–2008 were used to investigate geographical patterns and temporal variations of heatwave （HW） events. Dry and wet HW events were compared by different definitions. Regionally, both dry and wet HW events are commonly located in southeastern China in the monsoon area, with neither type occurring in the northeast part of Northeast China and Southwest China, while the north-northwest region of the country experiences dry HW events and a few wet HW events. In the southeast of the country, site dry HW events occurred from April to September and mostly in June, while site wet HW events occurred from April to October and mostly in September. In total, 163 regional wet HW events were identified. The ten longest regional wet HW events lasted for more than 20 days, while the mean duration for 163 events was about 11 days. For the top ten events, six occurred after the 1990s, compared with four before this time. Global surface warming was clear since 1979, but the frequency and severity of regional wet HW events were relatively low in the 1980s, increasing remarkably since the 1990s. Possible reasons for this might be the strong interdecadal and interannual variations in regional atmospheric circulations, as well as water transport related directly to temperature contrasts in different regions, rather than global-mean temperature changes.
文摘Net primary productivity （NPP） is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study the process-based Boreal Ecosystem Productivity Simulator （BEPS） was employed to study the changes of NPP in China＇s ecosystems for the period from 2000 to 2010. The BEPS model was first validated using gross primary productivity （GPP） measured at typical flux sites and forest NPP measured at different regions. Then it was driven with leaf area index （LAI） inversed from the Moderate Resolution Imaging Spectroradiometer （MODIS） reflec- tance and land cover products and meteorological data interpolated from observations at753 national basic meteorological stations to simulate NPP at daily time steps and a spatial resolution of 500m from January 1, 2000 to December 31, 2010. Validations show that BEPS is able to capture the seasonal variations of tower-based GPP and the spatial variability of forest NPP in different regions of China. Estimated national total of annual NPP varied from 2.63 to 2.84Pg C.yr-1, averaging 2.74Pg C.yr-1 during the study period. Simulated terrestrial NPP shows spatial patterns decreasing from the east to the west and from the south to the north, in association with land cover types and climate. South-west China makes the largest contribution to the national total of NPP while NPP in the North-west account for only 3.97% of the national total. During the recent 11 years, the temporal changes of NPP were heterogamous. NPP increased in 63.8% of China＇s landmass, mainly in areas north of the Yangtze River and decreased in most areas of southern China, owing to the low temperature freezing in early 2008 and the severe drought in late 2009.
基金the National Natural Science Foundation of China (No.40471121)the Field Station Foundation of the Chinese Academy,of Sciences.
文摘From studies undertaken during 1995-2004, annual budgets of CH4 emissions from natural wetlands and its temporal and spatial variations were examined throughout China, and various factors influencing CH4 emissions were also evaluated. The seasonal variation in CH4 emissions that increased with increasing plant growth reached its peak in August; decrease in the emissions was found in freshwater marshes but not in peatlands. Emissions were mainly controlled by temperature and depth of standing water. Low CH4 emissions at the early plant growing stages were not because of deficiency of organic C for CH4 production but because of low temperatures. Low temperatures not only reduced CH4 production but also stimulated CH4 oxidation by lowering the activity of other aerobic microbes which left more 02 in the rhizosphere for methanotrophs. Low summer temperatures （below 20 ℃） in the Qinghai-Tibetan Plateau lowered CH4 production and CH4 emission resulting in little or no seasonal variation of emissions. Diel and spatial variation in CH4 emissions depended on plant species. For plants that transport CH4 using the pressure-driven convective through-flow mechanism, diel variation in CH4 emissions was governed by diel variation of solar energy load （that produces temperature and vapor pressure differences within various plant tissues） and stomatal conductance. For plants that transport gases using the molecular diffusion mechanism only, the diel variation of CH4 emissions was because of differences in the magnitude of O2 produced through photosynthesis and then delivered into the rhizomes and/or rhizosphere for CH4 oxidation. Emergent plants could transport more CH4 than submerged plants because the former transport CH4 directly into the atmosphere rather than into water as do submerged plants where CH4 can be further be oxidized during its diffusion from water to the atmosphere. Emergent plants with high gas transport capacity could not only transport more CH4 into the atmosphere but also live in deeper water, whic
基金supported by the National Key Research and Development Program of China(No.2017YFC0907003)the National Natural Science Foundation of China(No.81973116 and 81573229)the Joint Research Funds for Shandong University and Karolinska Institute(No.SDU-KI-2020-03)。
文摘Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective prevention strategies.Methods:The data on incidence,mortality,and disability-adjusted life-years(DALYs)of GC in China from1990 to 2019 were obtained from the Global Burden of Disease Study(2019).The estimated annual percentage change(EAPC)was calculated to evaluate the temporal trends of disease burden of GC,and the package Nordpred in the R program was used to perform an age-period-cohort analysis to predict the numbers and rates of incidence and mortality in the next 25 years.Results:The number of incident cases of GC increased from 317.34 thousand in 1990 to 612.82 thousand in2019,while the age-standardized incidence rate(ASIR)of GC decreased from 37.56 per 100,000 in 1990 to 30.64 per 100,000 in 2019,with an EAPC of-0.41[95%confidence interval(95%CI):-0.77,-0.06].Pronounced temporal trends in mortality and DALYs of GC were observed.In the next 25 years,the numbers of new GC cases and deaths are expected to increase to 738.79 thousand and 454.80 thousand,respectively,while the rates of incidence and deaths should steadily decrease.The deaths and DALYs attributable to smoking were different for males and females.Conclusions:In China,despite the fact that the rates of GC have decreased during the past three decades,the numbers of new GC cases and deaths increased,and will continue to increase in the next 25 years.Additional strategies are needed to reduce the burden of GC,such as screening and early detection,novel treatments,and the prevention of risk factors.
基金National Basic Research Program of China(973 Program),No.2009CB421106National Natural Science Foundation of China,No.40901285
文摘Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by external factors, like agricultural policies. Since 2004, seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China. So far, few studies have investigated the effects of these policies on the rice cropping systems. In this study, based upon the long-term field survey information on paddy rice fields, we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region （PLR）, China. The results revealed that： （1） from 2004 to 2010, the decrement of paddy rice field was 46.76 km2 due to the land use change. （2） The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields. NDVI curves of single cropping rice fields showed one peak, while NDVI curves of double cropping rice fields displayed two peaks annually. NDVI of fallow field fluctuated between 0.15 and 0.40. NDVI of the flooded field during the transplanting period was relatively low, about 0.20±0.05, while NDVI during the period of panicle initiation to heading reached the highest level （above 0.80）. Then, several temporal windows were determined based upon the NDVI variations of different rice cropping systems. （3） With the spatial pattern of paddy rice field and the NDVI threshold within optimum temporal windows, the spatial variation of rice cropping systems was very obvious, with an increased multiple cropping index of rice about 20.2% from 2004 to 2010. The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR, China.
