Background:The cancer burden in the United States of America(USA)has decreased gradually.However,China is experiencing a transition in its cancer profiles,with greater incidence of cancers that were previously more co...Background:The cancer burden in the United States of America(USA)has decreased gradually.However,China is experiencing a transition in its cancer profiles,with greater incidence of cancers that were previously more common in the USA.This study compared the latest cancer profiles,trends,and determinants between China and USA.Methods:This was a comparative study using open-source data.Cancer cases and deaths in 2022 were calculated using cancer estimates from GLOBOCAN 2020 and population estimates from the United Nations.Trends in cancer incidence and mortality rates in the USA used data from the Surveillance,Epidemiology,and End Results program and National Center for Health Statistics.Chinese data were obtained from cancer registry reports.Data from the Global Burden of Disease 2019 and a decomposition method were used to express cancer deaths as the product of four determinant factors.Results:In 2022,there will be approximately 4,820,000 and 2,370,000 new cancer cases,and 3,210,000 and 640,000 cancer deaths in China and the USA,respectively.The most common cancers are lung cancer in China and breast cancer in the USA,and lung cancer is the leading cause of cancer death in both.Age-standardized incidence and mortality rates for lung cancer and colorectal cancer in the USA have decreased significantly recently,but rates of liver cancer have increased slightly.Rates of stomach,liver,and esophageal cancer decreased gradually in China,but rates have increased for colorectal cancer in the whole population,prostate cancer in men,and other seven cancer types in women.Increases in adult population size and population aging were major determinants for incremental cancer deaths,and case-fatality rates contributed to reduced cancer deaths in both countries.Conclusions:The decreasing cancer burden in liver,stomach,and esophagus,and increasing burden in lung,colorectum,breast,and prostate,mean that cancer profiles in China and the USA are converging.Population aging is a growing determinant of incremental cancer burden.Progre展开更多
Background： National Central Cancer Registry of China（NCCRC） updated nationwide cancer statistics using population-based cancer registry data in 2014 collected from all available cancer registries.Methods： In 2017...Background： National Central Cancer Registry of China（NCCRC） updated nationwide cancer statistics using population-based cancer registry data in 2014 collected from all available cancer registries.Methods： In 2017, 449 cancer registries submitted cancer registry data in 2014, among which 339 registries＇ data met the criteria of quality control and were included in analysis. These cancer registries covered 288,243,347 population, accounting for about 21.07% of the national population in 2014. Numbers of nationwide new cancer cases and deaths were estimated using calculated incidence and mortality rates and corresponding national population stratified by area, sex, age group and cancer type. The world Segi＇s population was applied for agestandardized rates.Results： A total of 3,804,000 new cancer cases were diagnosed, the crude incidence rate was 278.07/100,000（301.67/100,000 in males, 253.29/100,000 in females） and the age-standardized incidence rate by world standard population（ASIRW） was 186.53/100,000. Calculated age-standardized incidence rate was higher in urban areas than in rural areas（191.6/100,000 vs. 179.2/100,000）. South China had the highest cancer incidence rate while Southwest China had the lowest incidence rate. Cancer incidence rate was higher in female for population between20 to 54 years but was higher in male for population younger than 20 years or over 54 years. A total of 2,296,000 cancer deaths were reported, the crude mortality rate was 167.89/100,000（207.24/100,000 in males,126.54/100,000 in females） and the age-standardized mortality rate by world standard population（ASMRW） was106.09/100,000. Calculated age-standardized mortality rate was higher in rural areas than in urban areas（110.3/100,000 vs. 102.5/100,000）. East China had the highest cancer mortality rate while North China had the lowest mortality rate. The mortality rate in male was higher than that in female. Common cancer types and major causes of cancer death differed between age group and se展开更多
Objective： The National Central Cancer Registry （NCCR） collected population-based cancer registration data in 20l 1 from all cancer registries. National cancer incidence and mortality were compiled and cancer incid...Objective： The National Central Cancer Registry （NCCR） collected population-based cancer registration data in 20l 1 from all cancer registries. National cancer incidence and mortality were compiled and cancer incident new cases and cancer deaths were estimated. Methods： In 2014, there were 234 cancer registries submitted cancer incidence and deaths occurred in 2011. All datasets were checked and evaluated based on the criteria of data quality from NCCR. Total 177 registries＇ data were qualified and compiled for cancer statistics in 2011. The pooled data were stratified by area （urban/rural）, gender, age group （0, 1-4, 5-9, 10-14...85＋） and cancer type. Cancer incident cases and deaths were estimated using age-specific rates and national population in 2011. All incidence and death rates are age-standardized to the 2000 Chinese standard population and Segi＇s population expressed per 100,000 persons. Results： All 177 cancer registries （77 in urban and 100 in rural areas） covered 175,310,169 populations （98,341,507 in urban and 76,968,662 in rural areas）. The morphology verified cases （MV%） accounting for 70.14% and 2.44% of incident cases were identified through death certifications only （DCO%） with mortality to incidence ratio of 0.63. The estimates of new cancer incident cases and cancer deaths were 3,372,175 and 2,113,048 in 2011, respectively. The incidence rate was 250.28/100,000 （males 277.77/100,000, females 221.37/100,000）, and the age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 186.34/100,000 and 182.76/100,000 with the cumulative incidence rate （0-74 years old） of 21.20%. The cancer incidence and ASIRC in urban areas were 261.38/100,000 and 189.89/100,000 compared to 238.60/100,000 and 182.10/100,000 in rural areas, respectively. The cancer mortality was 156.83/100,000 （194.88/100,000 in males and 116.81/100,000 in females）, the age-standardized mortality rates by Chinese standa展开更多
Background： Population-based cancer registration data in 2012 from all available cancer registries were collected by the National Central Cancer Registry （NCCR）. NCCR estimated the numbers of new cancer cases and c...Background： Population-based cancer registration data in 2012 from all available cancer registries were collected by the National Central Cancer Registry （NCCR）. NCCR estimated the numbers of new cancer cases and cancer deaths in China with compiled cancer incidence and mortality rates. Methods： In 2015, there were 261 cancer registries submitted cancer incidence and deaths occurred in 2012. All the data were checked and evaluated based on the NCCR criteria of data quality. Qualified data from 193 registries were used for cancer statistics analysis as national estimation. The pooled data were stratified by area （urban/rural）, gender, age group [0, 1-4, 5-9, 10-14, ..., 85＋] and cancer type. New cancer cases and deaths were estimated using age-specific rates and corresponding national population in 2012. The Chinese census data in 2000 and Segi＇s population were applied for age-standardized rates. All the rates were expressed per 100,000 person-year. Results： Qualified 193 cancer registries （74 urban and 119 rural registries） covered 198,060,406 populations （100,450,109 in urban and 97,610,297 in rural areas）. The percentage of cases morphologically verified （NIV%） and death certificate-only cases （DCO%） were 69.13% and 2.38%, respectively, and the mortality to incidence rate ratio （M/I） was 0.62. A total of 3,586,200 new cancer cases and 2,186,600 cancer deaths were estimated in China in 2012. The incidence rate was 264.85/100,000 （289.30/100,000 in males, 239.15/100,000 in females）, the age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 191.89/100,000 and 187.83/100,000 with the cumulative incidence rate （0-74 age years old） of 21.82%. The cancer incidence, ASIRC and ASIRW in urban areas were 277.17/100,000, 195.56/100,000 and 190.88/100,000 compared to 251.20/100,000, 187.10/100,000 and 183.91/100,000 in rural areas, respectively. The cancer mortality was 161.49/ 100,000 （ 198.99/100,000 in展开更多
Objective： To explore the cancer patterns in areas with different urbanization rates（URR） in China with data from 255 population-based cancer registries in 2013, collected by the National Central Cancer Registry（N...Objective： To explore the cancer patterns in areas with different urbanization rates（URR） in China with data from 255 population-based cancer registries in 2013, collected by the National Central Cancer Registry（NCCR）.Methods： There were 347 cancer registries submitted cancer incidence and deaths occurred in 2013 to NCCR.All those data were checked and evaluated based on the NCCR criteria of data quality, and qualified data from 255 registries were used for this analysis. According to the proportion of non-agricultural population, we divided cities/counties into 3 levels： high level, with URR equal to 70% and higher; median level, with URR between 30%and 70%; and low level, with URR equal to 30% and less. Cancer incidences and mortalities were calculated,stratified by gender and age groups in different areas. The national population of Fifth Census in 2000 and Segi＇s population were applied for age-standardized rates.Results： Qualified 255 cancer registries covered 226,494,490 populations. The percentage of cases morphologically verified（MV%） and death certificate-only cases（DCO%） were 68.04% and 1.74%, respectively,and the mortality to incidence rate ratio（M/I） was 0.62. A total of 644,487 new cancer cases and 399,275 cancer deaths from the 255 cancer registries were submitted to NCCR in 2013. The incidence rate was 284.55/100,000（314.06/100,000 in males, 254.19/100,000 in females）, and the age-standardized incidence rates by Chinese standard population（ASIRC） and by world standard population（ASIRW） were 190.10/100,000 and 186.24/100,000 with the cumulative incidence rate（0–74 age years old） of 21.60%. The cancer mortality was 176.28/100,000（219.03/100,000 in males, 132.30/100,000 in females）, and the age-standardized mortality rates by Chinese standard population（ASMRC） and by world standard population（ASMRW） were 110.91/100,000 and 109.92/100,000, and the cumulative mortality rate（0–74 age years old） was 12.43%. Low urbanization areas were high 展开更多
Grain weight is a major determinant of crop grain yield and is controlled by naturally occurring quantitative trait loci （QTLs）. We earlier identified a major QTL that controls rice grain width and weight, GW5, whic...Grain weight is a major determinant of crop grain yield and is controlled by naturally occurring quantitative trait loci （QTLs）. We earlier identified a major QTL that controls rice grain width and weight, GW5, which was mapped to a recombination hotspot on rice chromosome 5. To gain a better understanding of how GW5 controls rice grain width, we conducted fine mapping of this locus and uncovered a 1 212-bp deletion associated with the increased grain width in the rice cultivar Asominori, in comparison with the slender grain rice IR24. In addition, genotyping analyses of 46 rice cultivars revealed that this deletion is highly correlated with the grain-width phenotype, suggesting that the GW5 deletion might have been selected during rice domestication. GW5 encodes a novel nuclear protein of 144 amino acids that is localized to the nucleus. Furthermore, we show that GW5 physically interacts with polyubiquitin in a yeast two-hybrid assay. Together, our results suggest that GW5 represents a major QTL underlying rice width and weight, and that it likely acts in the ubiquitin-proteasome pathway to regulate cell division during seed development. This study provides novel insights into the molecular mechanisms controlling rice grain development and suggests that GW5 could serve as a potential tool for high-yield breeding of crops.展开更多
Objective： The National Central Cancer Registry （NCCR） collected cancer registration data in 2009 from local cancer registries in 2012, and analyzed to describe cancer incidence and mortality in China. Methods： On...Objective： The National Central Cancer Registry （NCCR） collected cancer registration data in 2009 from local cancer registries in 2012, and analyzed to describe cancer incidence and mortality in China. Methods： On basis of the criteria of data quality from NCCR, data submitted from 104 registries were checked and evaluated. There were 72 registries＇ data qualified and accepted for cancer registry annual report in 2012. Descriptive analysis included incidence and mortality stratified by area （urban/rural）, sex, age group and cancer site. The top 10 common cancers in different groups, proportion and cumulative rates were also calculated. Chinese population census in 1982 and Segi＇s population were used for age-standardized incidence/mortality rates. Results： All 72 cancer registries covered a total of 85,470,522 population （57,489,009 in urban and 27,981,513 in rural areas）. The total new cancer incident cases and cancer deaths were 244,366 and 154,310, respectively. The morphology verified cases accounted for 67.23%, and 3.14% of incident cases only had information from death certifications. The crude incidence rate in Chinese cancer registration areas was 285.91/100,000 （males 317.97/100,000, females 253.09/100,000）, age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 146.87/100,000 and 191.72/100,000 with the cumulative incidence rate （0-74 age years old） of 22.08%. The cancer incidence and ASIRC were 303.39/100,000 and 150.31/100,000 in urban areas whereas in rural areas, they were 249.98/100,000 and 139.68/100,000, respectively. The cancer mortality in Chinese cancer registration areas was 180.54/100,000 （224.20/100,000 in males and 135.85/100,000 in females）, age-standardized mortality rates by Chinese standard population （ASMRC） and by world standard population （ASMRW） were 85.06/100,000 and 115.65/100,000, and the cumulative incidence rate （0-74 age years old） was 12.94%. The cancer mortal展开更多
Objective：Population-based cancer registration data in 2010 were collected,evaluated and analyzed by the National Central Cancer Registry （NCCR） of China.Cancer incident new cases and cancer deaths were estimated.M...Objective：Population-based cancer registration data in 2010 were collected,evaluated and analyzed by the National Central Cancer Registry （NCCR） of China.Cancer incident new cases and cancer deaths were estimated.Methods：There wvere 219 cancer registries submitted cancer incidence and death data in 2010.All data were checked and evaluated on basis of the criteria of data quality from NCCR.Total 145 registries＇ data were qualified and accepted for cancer statistics in 2010.Pooled data were stratified by urban/rural,area,sex,age group and cancer site.Cancer incident cases and deaths were estimated using age-specific rates and national population.The top ten common cancers in different groups,proportion and cumulative rate were also calculated.Chinese census in 2000 and Segi＇s population were used for age-standardized incidence/ mortality rates.Results：All 145 cancer registries （63 in urban and 82 in rural） covered a total of 158,403,248 population （92,433,739 in urban and 65,969,509 in rural areas）.The estimates of new cancer incident cases and cancer deaths were 3,093,039 and 1,956,622 in 2010,respectively.The morphology verified cases （MV％） accounted for 67.11％ and 2.99％ of incident cases were identified through death certifications only （DCO％） with mortality to incidence ratio （M/I） of 0.61.The crude incidence rate was 235.23/100,000 （268.65/100,000 in males,200.21/100,000 in females）,age-standardized incidence rates by Chinese standard population （ASIRC,2000） and by world standard population （ASIRW） were 184.58/100,000 and 181.49/100,000 with the cumulative incidence rate （0-74 years old） of 21.l 1％.The cancer incidence and ASIRC were 256.41/100,000 and 187.53/100,000 in urban areas whereas in rural areas,they were 213.71/100,000 and 181.10/100,000,respectively.The crude cancer mortality in China was 148.81/100,000 （186.37/100,000 in males and 109.42/100,000 in females）,age-standardized incidence rates by Chinese standard population （ASMRC,2000�展开更多
Cancer is still a major health problem in China although numerous efforts have been made for its prevention and control.Findings from this study showed that lung cancer remains the most common type of cancer diagnosed...Cancer is still a major health problem in China although numerous efforts have been made for its prevention and control.Findings from this study showed that lung cancer remains the most common type of cancer diagnosed,and was attributed to nearly 30%of all cancer-related deaths.The incidence of the five most common cancers,in China,in 2015,including cancers of the lungs,stomach,colorectum,liver and breast,accounted for almost 60%of all cancers diagnosed.The high cancer burden in China highlights the need for further improvement in health education,professional training and the building up an anti-cancer network for introducing and implementing sustainable actions for cancer control.展开更多
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
AIM:To determine the resistance patterns of Helicobacter pylori(H.pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time.METHODS:In this prospective,serial and cros...AIM:To determine the resistance patterns of Helicobacter pylori(H.pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time.METHODS:In this prospective,serial and crosssectional study,H.pylori cultures were successfully obtained from 371 and 950 patients(never receiving eradication) during 2009-2010 and 2013-2014,respectively.Resistance to amoxicillin,clarithromycin,metronidazole,levofloxacin,tetracycline,and rifampicin was determined by Epsilometer test.RESULTS:The resistance rates of isolates obtained during 2009-2010 were 66.8%,39.9%,34.5%,15.4%,6.7%,and 4.9% to metronidazole,clarithromycin,levofloxacin,rifampicin,amoxicillin and tetracycline,respectively; and the corresponding rates for isolates during 2013-2014 were 63.4%,52.6%,54.8%,18.2%,4.4% and 7.3%,respectively.The resistance rates to clarithromycin and levofloxacin were significantly increased after four years.In 2009-2010,14.6% of H.pylori isolates were susceptible to all tested antibiotics,with mono(33.7%),double(28.3%),triple(16.7%),quadruple(6.2%),quintuple(0.3%) and sextuple resistance(0.3%) also being detected.In 2013-2014,9.4% were susceptible to all tested antibiotics,and mono(27.6%),double(28.4%),triple(24.9%),quadruple(7.3%),quintuple(2.3%) and sextuple resistance(0.1%) was also observed.More multiple resistant H.pylori isolates were found during 2013-2014.Gender(to levofloxacin and metronidazole),age(to levofloxacin) and endoscopic findings(to clarithromycin) were independent factors influencing antibiotic resistance.CONCLUSION:H.pylori resistance to commonly used antibiotics in Beijing is high with increased multiple antibiotic resistance.展开更多
A genetic linkage map of cotton was constructed with a newly developed molecular marker-SRAP (sequence-related amplified polymorphism) using a population consisting of 129 F2 individuals derived from the interspecific...A genetic linkage map of cotton was constructed with a newly developed molecular marker-SRAP (sequence-related amplified polymorphism) using a population consisting of 129 F2 individuals derived from the interspecific cross of Handan208 Pima90. A total of 136 primer pairs were used to detect polymorphisms between the two parents and 76 primer pairs with better polymorphisms were picked out to analyze the F2 population. 285 polymorphic bands were generated in total with an average of 3.75 polymorphic bands per pair of primers. The primer pair showing most polymorphic bands was the combination of me3 and em2, which produced 13 polymorphic bands. The 285 loci were used to construct linkage map with MAPMAKER/EXP3.0 and 237 loci were mapped at a LOD≥3.0 on 39 linkage groups. The total length of the map is 3030.7 cM, covering 65.4% of the whole cotton genome, and the average distance between adjacent markers is 12.79 cM. All the markers are distributed evenly among the linkage groups without clustering of loci. This is the first linkage map of cotton comprised of SRAP markers.展开更多
This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and bett...This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reas- sess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteris- tics since the Neoproterozoic. The four evolutionary stages are： （1） The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. （2） The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. （3） The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. （4） The association and differentiation evolution of plate tectonics and intraconti- nental tectonics, and the dynamic characteristics under the Meso-Cenozoic modem global plate tectonic regime.展开更多
BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satel...BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.展开更多
Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the a...Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.展开更多
Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution.Extensive damage to human organs,such as liver,kidney,digestion sys...Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution.Extensive damage to human organs,such as liver,kidney,digestion system,and nervous system can be caused by uptake of excess heavy metals.Heavy metals in the environment can originate from both natural and anthropogenic sources.Although contamination of heavy metals has been known to be a severe environmental problem for decades,it is still getting worse in recent years and there are few feasible approaches to resolve this problem.Due to their high toxicity,prevalent existence and persistence in the environment,lead(Pb),mercury(Hg),cadmium(Cd),chromium(Cr) and arsenic(As) are commonly considered as the priority heavy metals which should be concerned and their emission should be controlled in China.This paper reviewed the pollution of heavy metals in China,focusing on the following four aspects:current status of heavy metal pollution in China,sources of heavy metals in China,toxicity and potential risk,and possible reduction strategies.展开更多
Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dorman...Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.展开更多
Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982...Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982 to 1999. In order to eliminate the effects of non-vegetation factors, we characterized areas with NDVI < 0.1 as sparsely vegetated areas and areas with NDVI ≥ 0.1 as vegetated areas. The results showed that increasing NDVI trends were evident, to varying extents, in almost all regions in China in the 18 years, indicating that vegetation activity has been rising in recent years in these regions. Compared to the early 1980s, the vegetated area increased by 3.5% by the late 1990s, while the sparsely vegetated area declined by 18.1% in the same period. The national total mean annual NDVI increased by 7.4% during the study period. Extended growing seasons and increased plant growth rates ac-counted for the bulk of these increases, while increases in temperature and summer rainfall, and strengthening agricultural activity were also likely important factors. NDVI changes in China ex-hibited relatively large spatial heterogeneity; the eastern coastal regions experienced declining or indiscernibly rising trends, while agricultural regions and western China experienced marked increases. Such a pattern was due primarily to urbanization, agricultural activity, regional climate characteristics, and different vegetation responses to regional climate changes.展开更多
基金Chinese Academy of Medical Sciences(No.2021-I2M-1-033)National Natural Science Foundation of China(No.81974492)+1 种基金Jing-jin-ji Special Projects for Basic Research Cooperation(No.J200017)Sanming Project of the Medicine in Shenzhen(No.SZSM201911015)。
文摘Background:The cancer burden in the United States of America(USA)has decreased gradually.However,China is experiencing a transition in its cancer profiles,with greater incidence of cancers that were previously more common in the USA.This study compared the latest cancer profiles,trends,and determinants between China and USA.Methods:This was a comparative study using open-source data.Cancer cases and deaths in 2022 were calculated using cancer estimates from GLOBOCAN 2020 and population estimates from the United Nations.Trends in cancer incidence and mortality rates in the USA used data from the Surveillance,Epidemiology,and End Results program and National Center for Health Statistics.Chinese data were obtained from cancer registry reports.Data from the Global Burden of Disease 2019 and a decomposition method were used to express cancer deaths as the product of four determinant factors.Results:In 2022,there will be approximately 4,820,000 and 2,370,000 new cancer cases,and 3,210,000 and 640,000 cancer deaths in China and the USA,respectively.The most common cancers are lung cancer in China and breast cancer in the USA,and lung cancer is the leading cause of cancer death in both.Age-standardized incidence and mortality rates for lung cancer and colorectal cancer in the USA have decreased significantly recently,but rates of liver cancer have increased slightly.Rates of stomach,liver,and esophageal cancer decreased gradually in China,but rates have increased for colorectal cancer in the whole population,prostate cancer in men,and other seven cancer types in women.Increases in adult population size and population aging were major determinants for incremental cancer deaths,and case-fatality rates contributed to reduced cancer deaths in both countries.Conclusions:The decreasing cancer burden in liver,stomach,and esophagus,and increasing burden in lung,colorectum,breast,and prostate,mean that cancer profiles in China and the USA are converging.Population aging is a growing determinant of incremental cancer burden.Progre
基金supported by Ministry of Science and Technology (2014FY121100)CAMS Innovation Fund for Medical Sciences (CIFMS) (201612M-2-004)
文摘Background： National Central Cancer Registry of China（NCCRC） updated nationwide cancer statistics using population-based cancer registry data in 2014 collected from all available cancer registries.Methods： In 2017, 449 cancer registries submitted cancer registry data in 2014, among which 339 registries＇ data met the criteria of quality control and were included in analysis. These cancer registries covered 288,243,347 population, accounting for about 21.07% of the national population in 2014. Numbers of nationwide new cancer cases and deaths were estimated using calculated incidence and mortality rates and corresponding national population stratified by area, sex, age group and cancer type. The world Segi＇s population was applied for agestandardized rates.Results： A total of 3,804,000 new cancer cases were diagnosed, the crude incidence rate was 278.07/100,000（301.67/100,000 in males, 253.29/100,000 in females） and the age-standardized incidence rate by world standard population（ASIRW） was 186.53/100,000. Calculated age-standardized incidence rate was higher in urban areas than in rural areas（191.6/100,000 vs. 179.2/100,000）. South China had the highest cancer incidence rate while Southwest China had the lowest incidence rate. Cancer incidence rate was higher in female for population between20 to 54 years but was higher in male for population younger than 20 years or over 54 years. A total of 2,296,000 cancer deaths were reported, the crude mortality rate was 167.89/100,000（207.24/100,000 in males,126.54/100,000 in females） and the age-standardized mortality rate by world standard population（ASMRW） was106.09/100,000. Calculated age-standardized mortality rate was higher in rural areas than in urban areas（110.3/100,000 vs. 102.5/100,000）. East China had the highest cancer mortality rate while North China had the lowest mortality rate. The mortality rate in male was higher than that in female. Common cancer types and major causes of cancer death differed between age group and se
文摘Objective： The National Central Cancer Registry （NCCR） collected population-based cancer registration data in 20l 1 from all cancer registries. National cancer incidence and mortality were compiled and cancer incident new cases and cancer deaths were estimated. Methods： In 2014, there were 234 cancer registries submitted cancer incidence and deaths occurred in 2011. All datasets were checked and evaluated based on the criteria of data quality from NCCR. Total 177 registries＇ data were qualified and compiled for cancer statistics in 2011. The pooled data were stratified by area （urban/rural）, gender, age group （0, 1-4, 5-9, 10-14...85＋） and cancer type. Cancer incident cases and deaths were estimated using age-specific rates and national population in 2011. All incidence and death rates are age-standardized to the 2000 Chinese standard population and Segi＇s population expressed per 100,000 persons. Results： All 177 cancer registries （77 in urban and 100 in rural areas） covered 175,310,169 populations （98,341,507 in urban and 76,968,662 in rural areas）. The morphology verified cases （MV%） accounting for 70.14% and 2.44% of incident cases were identified through death certifications only （DCO%） with mortality to incidence ratio of 0.63. The estimates of new cancer incident cases and cancer deaths were 3,372,175 and 2,113,048 in 2011, respectively. The incidence rate was 250.28/100,000 （males 277.77/100,000, females 221.37/100,000）, and the age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 186.34/100,000 and 182.76/100,000 with the cumulative incidence rate （0-74 years old） of 21.20%. The cancer incidence and ASIRC in urban areas were 261.38/100,000 and 189.89/100,000 compared to 238.60/100,000 and 182.10/100,000 in rural areas, respectively. The cancer mortality was 156.83/100,000 （194.88/100,000 in males and 116.81/100,000 in females）, the age-standardized mortality rates by Chinese standa
文摘Background： Population-based cancer registration data in 2012 from all available cancer registries were collected by the National Central Cancer Registry （NCCR）. NCCR estimated the numbers of new cancer cases and cancer deaths in China with compiled cancer incidence and mortality rates. Methods： In 2015, there were 261 cancer registries submitted cancer incidence and deaths occurred in 2012. All the data were checked and evaluated based on the NCCR criteria of data quality. Qualified data from 193 registries were used for cancer statistics analysis as national estimation. The pooled data were stratified by area （urban/rural）, gender, age group [0, 1-4, 5-9, 10-14, ..., 85＋] and cancer type. New cancer cases and deaths were estimated using age-specific rates and corresponding national population in 2012. The Chinese census data in 2000 and Segi＇s population were applied for age-standardized rates. All the rates were expressed per 100,000 person-year. Results： Qualified 193 cancer registries （74 urban and 119 rural registries） covered 198,060,406 populations （100,450,109 in urban and 97,610,297 in rural areas）. The percentage of cases morphologically verified （NIV%） and death certificate-only cases （DCO%） were 69.13% and 2.38%, respectively, and the mortality to incidence rate ratio （M/I） was 0.62. A total of 3,586,200 new cancer cases and 2,186,600 cancer deaths were estimated in China in 2012. The incidence rate was 264.85/100,000 （289.30/100,000 in males, 239.15/100,000 in females）, the age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 191.89/100,000 and 187.83/100,000 with the cumulative incidence rate （0-74 age years old） of 21.82%. The cancer incidence, ASIRC and ASIRW in urban areas were 277.17/100,000, 195.56/100,000 and 190.88/100,000 compared to 251.20/100,000, 187.10/100,000 and 183.91/100,000 in rural areas, respectively. The cancer mortality was 161.49/ 100,000 （ 198.99/100,000 in
基金supported by Ministry of Science and Technology of China (Grant No. 2014FY121100)the National Natural Science Fund (Grant No. 81602931)
文摘Objective： To explore the cancer patterns in areas with different urbanization rates（URR） in China with data from 255 population-based cancer registries in 2013, collected by the National Central Cancer Registry（NCCR）.Methods： There were 347 cancer registries submitted cancer incidence and deaths occurred in 2013 to NCCR.All those data were checked and evaluated based on the NCCR criteria of data quality, and qualified data from 255 registries were used for this analysis. According to the proportion of non-agricultural population, we divided cities/counties into 3 levels： high level, with URR equal to 70% and higher; median level, with URR between 30%and 70%; and low level, with URR equal to 30% and less. Cancer incidences and mortalities were calculated,stratified by gender and age groups in different areas. The national population of Fifth Census in 2000 and Segi＇s population were applied for age-standardized rates.Results： Qualified 255 cancer registries covered 226,494,490 populations. The percentage of cases morphologically verified（MV%） and death certificate-only cases（DCO%） were 68.04% and 1.74%, respectively,and the mortality to incidence rate ratio（M/I） was 0.62. A total of 644,487 new cancer cases and 399,275 cancer deaths from the 255 cancer registries were submitted to NCCR in 2013. The incidence rate was 284.55/100,000（314.06/100,000 in males, 254.19/100,000 in females）, and the age-standardized incidence rates by Chinese standard population（ASIRC） and by world standard population（ASIRW） were 190.10/100,000 and 186.24/100,000 with the cumulative incidence rate（0–74 age years old） of 21.60%. The cancer mortality was 176.28/100,000（219.03/100,000 in males, 132.30/100,000 in females）, and the age-standardized mortality rates by Chinese standard population（ASMRC） and by world standard population（ASMRW） were 110.91/100,000 and 109.92/100,000, and the cumulative mortality rate（0–74 age years old） was 12.43%. Low urbanization areas were high
文摘Grain weight is a major determinant of crop grain yield and is controlled by naturally occurring quantitative trait loci （QTLs）. We earlier identified a major QTL that controls rice grain width and weight, GW5, which was mapped to a recombination hotspot on rice chromosome 5. To gain a better understanding of how GW5 controls rice grain width, we conducted fine mapping of this locus and uncovered a 1 212-bp deletion associated with the increased grain width in the rice cultivar Asominori, in comparison with the slender grain rice IR24. In addition, genotyping analyses of 46 rice cultivars revealed that this deletion is highly correlated with the grain-width phenotype, suggesting that the GW5 deletion might have been selected during rice domestication. GW5 encodes a novel nuclear protein of 144 amino acids that is localized to the nucleus. Furthermore, we show that GW5 physically interacts with polyubiquitin in a yeast two-hybrid assay. Together, our results suggest that GW5 represents a major QTL underlying rice width and weight, and that it likely acts in the ubiquitin-proteasome pathway to regulate cell division during seed development. This study provides novel insights into the molecular mechanisms controlling rice grain development and suggests that GW5 could serve as a potential tool for high-yield breeding of crops.
文摘Objective： The National Central Cancer Registry （NCCR） collected cancer registration data in 2009 from local cancer registries in 2012, and analyzed to describe cancer incidence and mortality in China. Methods： On basis of the criteria of data quality from NCCR, data submitted from 104 registries were checked and evaluated. There were 72 registries＇ data qualified and accepted for cancer registry annual report in 2012. Descriptive analysis included incidence and mortality stratified by area （urban/rural）, sex, age group and cancer site. The top 10 common cancers in different groups, proportion and cumulative rates were also calculated. Chinese population census in 1982 and Segi＇s population were used for age-standardized incidence/mortality rates. Results： All 72 cancer registries covered a total of 85,470,522 population （57,489,009 in urban and 27,981,513 in rural areas）. The total new cancer incident cases and cancer deaths were 244,366 and 154,310, respectively. The morphology verified cases accounted for 67.23%, and 3.14% of incident cases only had information from death certifications. The crude incidence rate in Chinese cancer registration areas was 285.91/100,000 （males 317.97/100,000, females 253.09/100,000）, age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 146.87/100,000 and 191.72/100,000 with the cumulative incidence rate （0-74 age years old） of 22.08%. The cancer incidence and ASIRC were 303.39/100,000 and 150.31/100,000 in urban areas whereas in rural areas, they were 249.98/100,000 and 139.68/100,000, respectively. The cancer mortality in Chinese cancer registration areas was 180.54/100,000 （224.20/100,000 in males and 135.85/100,000 in females）, age-standardized mortality rates by Chinese standard population （ASMRC） and by world standard population （ASMRW） were 85.06/100,000 and 115.65/100,000, and the cumulative incidence rate （0-74 age years old） was 12.94%. The cancer mortal
文摘Objective：Population-based cancer registration data in 2010 were collected,evaluated and analyzed by the National Central Cancer Registry （NCCR） of China.Cancer incident new cases and cancer deaths were estimated.Methods：There wvere 219 cancer registries submitted cancer incidence and death data in 2010.All data were checked and evaluated on basis of the criteria of data quality from NCCR.Total 145 registries＇ data were qualified and accepted for cancer statistics in 2010.Pooled data were stratified by urban/rural,area,sex,age group and cancer site.Cancer incident cases and deaths were estimated using age-specific rates and national population.The top ten common cancers in different groups,proportion and cumulative rate were also calculated.Chinese census in 2000 and Segi＇s population were used for age-standardized incidence/ mortality rates.Results：All 145 cancer registries （63 in urban and 82 in rural） covered a total of 158,403,248 population （92,433,739 in urban and 65,969,509 in rural areas）.The estimates of new cancer incident cases and cancer deaths were 3,093,039 and 1,956,622 in 2010,respectively.The morphology verified cases （MV％） accounted for 67.11％ and 2.99％ of incident cases were identified through death certifications only （DCO％） with mortality to incidence ratio （M/I） of 0.61.The crude incidence rate was 235.23/100,000 （268.65/100,000 in males,200.21/100,000 in females）,age-standardized incidence rates by Chinese standard population （ASIRC,2000） and by world standard population （ASIRW） were 184.58/100,000 and 181.49/100,000 with the cumulative incidence rate （0-74 years old） of 21.l 1％.The cancer incidence and ASIRC were 256.41/100,000 and 187.53/100,000 in urban areas whereas in rural areas,they were 213.71/100,000 and 181.10/100,000,respectively.The crude cancer mortality in China was 148.81/100,000 （186.37/100,000 in males and 109.42/100,000 in females）,age-standardized incidence rates by Chinese standard population （ASMRC,2000�
基金CAMS Innovation Fund for Medical Sciences,Grant/Award Number:2016-12M-2-004Sanming Project of Medicine in Shenzhen,Grant/Award Number:SZSM201911015。
文摘Cancer is still a major health problem in China although numerous efforts have been made for its prevention and control.Findings from this study showed that lung cancer remains the most common type of cancer diagnosed,and was attributed to nearly 30%of all cancer-related deaths.The incidence of the five most common cancers,in China,in 2015,including cancers of the lungs,stomach,colorectum,liver and breast,accounted for almost 60%of all cancers diagnosed.The high cancer burden in China highlights the need for further improvement in health education,professional training and the building up an anti-cancer network for introducing and implementing sustainable actions for cancer control.
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Supported by National Science and Technology Pillar Program during the Twelfth Five-year Plan Period,No.2012BAI06B02the Capital Health Research and Development of Special,No.2011-4032-02
文摘AIM:To determine the resistance patterns of Helicobacter pylori(H.pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time.METHODS:In this prospective,serial and crosssectional study,H.pylori cultures were successfully obtained from 371 and 950 patients(never receiving eradication) during 2009-2010 and 2013-2014,respectively.Resistance to amoxicillin,clarithromycin,metronidazole,levofloxacin,tetracycline,and rifampicin was determined by Epsilometer test.RESULTS:The resistance rates of isolates obtained during 2009-2010 were 66.8%,39.9%,34.5%,15.4%,6.7%,and 4.9% to metronidazole,clarithromycin,levofloxacin,rifampicin,amoxicillin and tetracycline,respectively; and the corresponding rates for isolates during 2013-2014 were 63.4%,52.6%,54.8%,18.2%,4.4% and 7.3%,respectively.The resistance rates to clarithromycin and levofloxacin were significantly increased after four years.In 2009-2010,14.6% of H.pylori isolates were susceptible to all tested antibiotics,with mono(33.7%),double(28.3%),triple(16.7%),quadruple(6.2%),quintuple(0.3%) and sextuple resistance(0.3%) also being detected.In 2013-2014,9.4% were susceptible to all tested antibiotics,and mono(27.6%),double(28.4%),triple(24.9%),quadruple(7.3%),quintuple(2.3%) and sextuple resistance(0.1%) was also observed.More multiple resistant H.pylori isolates were found during 2013-2014.Gender(to levofloxacin and metronidazole),age(to levofloxacin) and endoscopic findings(to clarithromycin) were independent factors influencing antibiotic resistance.CONCLUSION:H.pylori resistance to commonly used antibiotics in Beijing is high with increased multiple antibiotic resistance.
基金This work was supported by the National"863"High Technology Foundation(Grant Nos.2001AA211121 and 2002AA-211031)the National"948"Foundation(Grant No.201012).
文摘A genetic linkage map of cotton was constructed with a newly developed molecular marker-SRAP (sequence-related amplified polymorphism) using a population consisting of 129 F2 individuals derived from the interspecific cross of Handan208 Pima90. A total of 136 primer pairs were used to detect polymorphisms between the two parents and 76 primer pairs with better polymorphisms were picked out to analyze the F2 population. 285 polymorphic bands were generated in total with an average of 3.75 polymorphic bands per pair of primers. The primer pair showing most polymorphic bands was the combination of me3 and em2, which produced 13 polymorphic bands. The 285 loci were used to construct linkage map with MAPMAKER/EXP3.0 and 237 loci were mapped at a LOD≥3.0 on 39 linkage groups. The total length of the map is 3030.7 cM, covering 65.4% of the whole cotton genome, and the average distance between adjacent markers is 12.79 cM. All the markers are distributed evenly among the linkage groups without clustering of loci. This is the first linkage map of cotton comprised of SRAP markers.
基金supported by the special grant of Ministry of Science and Technology of the People’s Republic of China for State Key Laboratory of Continental Dynamics,Northwest University,the key research project of Sinopec Group(Grant No.YPH08012)the National Natural Science Foundation of China(Grant Nos.41190072,41190073,41190074,41190070)
文摘This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reas- sess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteris- tics since the Neoproterozoic. The four evolutionary stages are： （1） The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. （2） The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. （3） The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. （4） The association and differentiation evolution of plate tectonics and intraconti- nental tectonics, and the dynamic characteristics under the Meso-Cenozoic modem global plate tectonic regime.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.41020144004,41374019,41104022)the National High Technology Research and Development Program of China(Grant No.2013AA122501)
文摘BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.
基金Supported by the National Natural Science Foundation of China,No.81300251
文摘Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.
基金supported by the National Basic Research Program of China(2013CB430004)the National Natural Science Foundation of China(20937002,21120102040,20977107,21075130)
文摘Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution.Extensive damage to human organs,such as liver,kidney,digestion system,and nervous system can be caused by uptake of excess heavy metals.Heavy metals in the environment can originate from both natural and anthropogenic sources.Although contamination of heavy metals has been known to be a severe environmental problem for decades,it is still getting worse in recent years and there are few feasible approaches to resolve this problem.Due to their high toxicity,prevalent existence and persistence in the environment,lead(Pb),mercury(Hg),cadmium(Cd),chromium(Cr) and arsenic(As) are commonly considered as the priority heavy metals which should be concerned and their emission should be controlled in China.This paper reviewed the pollution of heavy metals in China,focusing on the following four aspects:current status of heavy metal pollution in China,sources of heavy metals in China,toxicity and potential risk,and possible reduction strategies.
文摘Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also impor- tant for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA （abscisic acid） and GAs （gibberellins） are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions （crosstalk） of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.40024101&90211016).
文摘Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982 to 1999. In order to eliminate the effects of non-vegetation factors, we characterized areas with NDVI < 0.1 as sparsely vegetated areas and areas with NDVI ≥ 0.1 as vegetated areas. The results showed that increasing NDVI trends were evident, to varying extents, in almost all regions in China in the 18 years, indicating that vegetation activity has been rising in recent years in these regions. Compared to the early 1980s, the vegetated area increased by 3.5% by the late 1990s, while the sparsely vegetated area declined by 18.1% in the same period. The national total mean annual NDVI increased by 7.4% during the study period. Extended growing seasons and increased plant growth rates ac-counted for the bulk of these increases, while increases in temperature and summer rainfall, and strengthening agricultural activity were also likely important factors. NDVI changes in China ex-hibited relatively large spatial heterogeneity; the eastern coastal regions experienced declining or indiscernibly rising trends, while agricultural regions and western China experienced marked increases. Such a pattern was due primarily to urbanization, agricultural activity, regional climate characteristics, and different vegetation responses to regional climate changes.
