The habitat of giant pandas borders the living areas of farmers in surrounding communities. Due to the low level of economic development and resource used method, the life of community farmers depends on the natural r...The habitat of giant pandas borders the living areas of farmers in surrounding communities. Due to the low level of economic development and resource used method, the life of community farmers depends on the natural resources of the habitat of giant pandas. Analyzing the natural resource utilization of farmers in communities around the habitat of giant pandas is conducive to formulating more reasonable management policies and protecting the habitat of giant pandas more effectively. Based on the field survey data, this paper classifies the main ways of community farmers using the natural resources of the habitat of giant pandas, counts the quantity of resources used and analyzes their change trends. On this basis, this paper selects indicators, constructs a model and analyzes the main influencing factors affecting the natural resources utilization of community farmers from three aspects: the individual characteristics of household heads, the family characteristics of community farmers and the residence characteristics of community farmers.展开更多
The recurrence of colorectal adenoma(CRA)is high.Although there are guidelines for colonoscopy surveillance after polypectomy in other countries,little is known about its recurrence rate and recurrence peak,especially...The recurrence of colorectal adenoma(CRA)is high.Although there are guidelines for colonoscopy surveillance after polypectomy in other countries,little is known about its recurrence rate and recurrence peak,especially in China.The aim of the present research is to investigate how long after polypectomy follow-up should take and to analyze risk factors of recurrence.1208 patients who received polypectomies fromfive clinical research centers in four regions of China(Shanghai,Guangzhou,Nanjing and Beijing)were included.They were divided into 4 groups:group A(follow-up≤1 year after poly-pectomy),group B(follow-up 2–3 years after polypect-omy),group C(follow-up 4–5 years after polypectomy),and group D(follow-up>5 years after polypectomy).The sex,age,adenoma location,size,number,and pathological characteristics were compared.On the whole,the recur-rence rate was 59.46%in group A,61.09%in group B,78.07%in group C,and 87.12%in group D,which indicated an increased tendency with a prolonged follow-up duration.There was a significant difference between group A and C or D,and between group B and C or D(P<0.01),but there was no statistical difference between group A and B.Additionally,the recurrent patients in thefirst year had a recurrence rate of 97.33%in thefirst three years(59.46/61.09),which means that the peak of recurrence was almost entirely concentrated in thefirst year.The recurrence rate was higher in males and the elder.The risk factors included multiple numbers,villous feature,high-grade dysplasia of medium or smaller size and location in the distal colon.In conclusion,the peak of recurrence was almost totally concentrated in thefirst year;meanwhile,thefirst year follow-up is of critical importance in China.It may not be necessary to do the follow-up examination during the second and third years,but after three years,another colonoscopy should be undertaken.展开更多
The bioavailability of phosphorus in lake sediment mainly depends on its forms. Therefore, reactive phosphorus (RP) pool of the sediment in a shallow eutrophic lake(Donghu Lake) was determined seasonally and spatia...The bioavailability of phosphorus in lake sediment mainly depends on its forms. Therefore, reactive phosphorus (RP) pool of the sediment in a shallow eutrophic lake(Donghu Lake) was determined seasonally and spatially by sequential chemical extraction according to the scheme proposed by Psenner et al. (Psenner, 1985) and its modified version respectively. The ammonium chloride extracted 3%—7% of the total reactive phosphorus (Tot-RP), while the distilled water extracted less(<3%). These two forms of P were significantly higher at the most eutrophic stations(I and IV). The sum of BD-RP(reductant soluble P) and NaOH-RP extracted accounted for 57%—81% of Tot-RP, which could play significant roles in P cycling. The percentages of HCl-extractable RP in the sediments of station III, however, were usually much more than those of other stations, which could reflect the original geochemistrical characteristics and trophic status of the sediments. It was noted that the sediment RP in different fractions varied in different months studied.展开更多
The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tes...The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tester, XRD, optical microscopy （OM）, scanning electron microscopy （SEM）, and electron probe micro-analyzer （EPMA）. The results showed that significant differences existed in the tensile strength, yield strength and impact toughness between HPS and PCS. After 72 h cyclic immersion accelerated corrosion test, the inner rust layer on HPS was com- posed of a-FeOOH phase and denser than that on PCS that was a mixture of a-FeOOH and Fe3 04. The rust formed on HPS provides better protection and HPS has lower corrosion rates than PCS. Copper and chromium in HPS en- rich in the rust layer and enhance the compactness of the rust layer. Based on the results of the accelerated corrosion tests and rust layer analysis, the roles of Cu and Cr against corrosion are discussed, providing HPS with chemical specification which has been industrially successful to produce weathering steel for bridge structure.展开更多
AIM:To study the characteristics of APC(adenomatous polyposis coli)gene germline mutation in Chinese patients with familial adenomatous polyposis(FAP).METHODS:APC gene from 14 FAP families was amplified by polymerase ...AIM:To study the characteristics of APC(adenomatous polyposis coli)gene germline mutation in Chinese patients with familial adenomatous polyposis(FAP).METHODS:APC gene from 14 FAP families was amplified by polymerase chain reaction(PCR)and underwent direct sequencing to determine the micromutation type.For the samples without micromutation,the large fragment deletion of APC gene was examined by multiplex ligation-dependent probe amplification(MLPA).RESULTS:There were gene micromutations in 9 families with a micromutation detection rate of 64.3%(9/14),including 6 frameshift mutations(66.7%),1 nonsense mutation(11.1%)and 2 splicing mutations(22.2%).Large fragment deletions were detected by MLPA in 2 families.The total mutation detection rate of micromutations and large fragment deletions was 78.6%(11/14).CONCLUSION:The detection rate of APC gene germline mutation can be improved by direct sequencing combined with MLPA large fragment deletion detection.展开更多
文摘The habitat of giant pandas borders the living areas of farmers in surrounding communities. Due to the low level of economic development and resource used method, the life of community farmers depends on the natural resources of the habitat of giant pandas. Analyzing the natural resource utilization of farmers in communities around the habitat of giant pandas is conducive to formulating more reasonable management policies and protecting the habitat of giant pandas more effectively. Based on the field survey data, this paper classifies the main ways of community farmers using the natural resources of the habitat of giant pandas, counts the quantity of resources used and analyzes their change trends. On this basis, this paper selects indicators, constructs a model and analyzes the main influencing factors affecting the natural resources utilization of community farmers from three aspects: the individual characteristics of household heads, the family characteristics of community farmers and the residence characteristics of community farmers.
基金supported by grant from the Ministry of Health,China(No:200802094)Ministry of Education,China(No:20090073110077)to Jingyuan Fanggrant from Shanghai JiaoTong University School of Medicine Foundation for Science and Technology(No:BXJ0914)to Huimin Chen.
文摘The recurrence of colorectal adenoma(CRA)is high.Although there are guidelines for colonoscopy surveillance after polypectomy in other countries,little is known about its recurrence rate and recurrence peak,especially in China.The aim of the present research is to investigate how long after polypectomy follow-up should take and to analyze risk factors of recurrence.1208 patients who received polypectomies fromfive clinical research centers in four regions of China(Shanghai,Guangzhou,Nanjing and Beijing)were included.They were divided into 4 groups:group A(follow-up≤1 year after poly-pectomy),group B(follow-up 2–3 years after polypect-omy),group C(follow-up 4–5 years after polypectomy),and group D(follow-up>5 years after polypectomy).The sex,age,adenoma location,size,number,and pathological characteristics were compared.On the whole,the recur-rence rate was 59.46%in group A,61.09%in group B,78.07%in group C,and 87.12%in group D,which indicated an increased tendency with a prolonged follow-up duration.There was a significant difference between group A and C or D,and between group B and C or D(P<0.01),but there was no statistical difference between group A and B.Additionally,the recurrent patients in thefirst year had a recurrence rate of 97.33%in thefirst three years(59.46/61.09),which means that the peak of recurrence was almost entirely concentrated in thefirst year.The recurrence rate was higher in males and the elder.The risk factors included multiple numbers,villous feature,high-grade dysplasia of medium or smaller size and location in the distal colon.In conclusion,the peak of recurrence was almost totally concentrated in thefirst year;meanwhile,thefirst year follow-up is of critical importance in China.It may not be necessary to do the follow-up examination during the second and third years,but after three years,another colonoscopy should be undertaken.
文摘The bioavailability of phosphorus in lake sediment mainly depends on its forms. Therefore, reactive phosphorus (RP) pool of the sediment in a shallow eutrophic lake(Donghu Lake) was determined seasonally and spatially by sequential chemical extraction according to the scheme proposed by Psenner et al. (Psenner, 1985) and its modified version respectively. The ammonium chloride extracted 3%—7% of the total reactive phosphorus (Tot-RP), while the distilled water extracted less(<3%). These two forms of P were significantly higher at the most eutrophic stations(I and IV). The sum of BD-RP(reductant soluble P) and NaOH-RP extracted accounted for 57%—81% of Tot-RP, which could play significant roles in P cycling. The percentages of HCl-extractable RP in the sediments of station III, however, were usually much more than those of other stations, which could reflect the original geochemistrical characteristics and trophic status of the sediments. It was noted that the sediment RP in different fractions varied in different months studied.
文摘The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tester, XRD, optical microscopy （OM）, scanning electron microscopy （SEM）, and electron probe micro-analyzer （EPMA）. The results showed that significant differences existed in the tensile strength, yield strength and impact toughness between HPS and PCS. After 72 h cyclic immersion accelerated corrosion test, the inner rust layer on HPS was com- posed of a-FeOOH phase and denser than that on PCS that was a mixture of a-FeOOH and Fe3 04. The rust formed on HPS provides better protection and HPS has lower corrosion rates than PCS. Copper and chromium in HPS en- rich in the rust layer and enhance the compactness of the rust layer. Based on the results of the accelerated corrosion tests and rust layer analysis, the roles of Cu and Cr against corrosion are discussed, providing HPS with chemical specification which has been industrially successful to produce weathering steel for bridge structure.
基金Supported by The National Natural Science Foundation of China,No.30940086
文摘AIM:To study the characteristics of APC(adenomatous polyposis coli)gene germline mutation in Chinese patients with familial adenomatous polyposis(FAP).METHODS:APC gene from 14 FAP families was amplified by polymerase chain reaction(PCR)and underwent direct sequencing to determine the micromutation type.For the samples without micromutation,the large fragment deletion of APC gene was examined by multiplex ligation-dependent probe amplification(MLPA).RESULTS:There were gene micromutations in 9 families with a micromutation detection rate of 64.3%(9/14),including 6 frameshift mutations(66.7%),1 nonsense mutation(11.1%)and 2 splicing mutations(22.2%).Large fragment deletions were detected by MLPA in 2 families.The total mutation detection rate of micromutations and large fragment deletions was 78.6%(11/14).CONCLUSION:The detection rate of APC gene germline mutation can be improved by direct sequencing combined with MLPA large fragment deletion detection.
