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1.
, China )     
采用脱氨再生几丁质凝胶亲和层析从萝卜叶中获得了PAGE圆盘电泳均一的溶菌酶,并通过微量蒸发扩散法获得其结晶。用pH动力学研究方法和化学修饰法对该酶的活性中心进行了初步研究,实验结果表明:-COOH(Glu/Asp)基团、Trp及His残基可能为酶活性所必需。采用对Tyr、Cys、Arg、Ser/Thr残基专一的修饰剂对酶作用后,酶活性基本上不受影响。同时,酶活性受到组胺和GlcNAc抑制。讨论了萝卜溶菌酶与鸡蛋清溶菌酶和木瓜溶菌酶的活性中心的相互差异。  相似文献   

2.
The first case of AIDS was reported in 1985 in China, but by the early 21st century, the government estimated that there were 840,000 citizens living with HIV/AIDS. The number is increasing rapidly. The major risk groups are injection drug users (IDUSs; 43%) and former plasma donors (27%), but rates among heterosexual groups are rising rapidly. Sentinel surveillance was initiated in 1986, and now includes IDUs, men-who-have-sex-with-men, sexually transmitted disease clinic attendees, antenatal women, long-distance truck drivers, and sex workers. Although the government was slow to respond to the epidemic in the late 20th century, it has made a vigorous response in the early 21st century. Components of that response include implementation and evaluation of harm reduction programs for IDUs, education to increase knowledge and reduce stigma, treatment and social support for rural and poor HIV/AIDS patients, widespread testing, and increased funding for HIV/AIDS programs. International agencies have been generous in their support of the government initiatives. To successfully combat the epidemic, China needs to develop and train the necessary infrastructure to implement its intervention programs, particularly in the rural areas, to vigorously combat stigma and discrimination, support research especially in the universities and research institutions other than the China Centers for Disease Control, develop a system for efficient exchange of research and program information, and update legislation to reflect the current situation.  相似文献   

3.
4.
Lead poisoning is one of the most significant environmental health threats which children face. The aim of the study was to evaluate the relationship between the blood lead level (BLL) of children and environmental pollution, as well as the effect of BLL on children's heath, in the biggest city in south-west China. A questionnaire survey was administered to 3,624 children's (6 months-7 years old) guardian in urban Chengdu from 2007 to 2009, collecting data on inhabited environment, living habits, and health status. All blood samples were collected for BLL test when the children came to the hospital. The analysis was conducted in West China Second University Hospital, Chengdu, China in December, 2009. A total of 3,624 children were included. The mean BLL was 62.31 μg/L. Three hundred thirty-three (9.2%) of 3,624 children's BLL were above 100 μg/L. Taking Chinese medicinal herbs usually, puffed foods, and substitutes of breast milk were risk factors (P < 0.05).The study shows that Chinese children's lead poisoning prevention and treatment lags far behind developed countries. The findings have implications for environmental health policy.  相似文献   

5.
This paper offers new evidence on human stature in south China during the second half of the 19th century and early part of the 20th. It is based on the records kept by the Government of Canada of 97,123 Chinese immigrants who were required to pay an entry tax between 1885 and 1949. While the study population included both sexes and all ages from infancy to old age, it was largely male, with most ages falling between 12 and 50. The data reveal an increase of over 4 cm in the adult heights of both sexes between 1850 and 1930. They also indicate an upward trend of over 5 cm in the heights of adolescent males. The mean heights of male immigrants fall in the lower range of those reported in other studies of stature in south China. The rising trends contrast with a pattern of stagnation and decline reported in other recent findings but are consistent with other recent evidence of increasing economic growth, real wages, and life expectancy in south China during this period. One likely cause of improved well-being is the influence of the migrants’ remittances on socioeconomic change in south China.  相似文献   

6.
A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium fastidium, Exserohilum pedicellatum, Monodictys asperospora, Papulaspora brachiata, Scolecobasidium anelli, Scolecobasidium verruculosum and Ulocladium tuberculatum are new to China. The other 31 taxa which have been previously reported from China are also listed. Specimens (dried cultures) and living cultures of all fungi studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).  相似文献   

7.
Conifer Woods of the Pliocene Age from Yunnan, China   总被引:1,自引:0,他引:1  
The Tertiary floras play an integral role in understanding the biodiversity and interactions between climate and vegetation in Yunnan, China. The fossil spores, pollen grains, and leaves in this region have been investiaged intensively. In comparison, the woods have been studied relatively little. A large number of Pliocene wood specimens was collected from the opencast lignite coal mine of Hongxing situated in Changning County of Yunnan Province. Among the collection, Tsuga cf. dumosa (D. Don) Eichler and Pinus cf. armandii Franchet were identified based on wood structures. The subtle feature oftori extensions is reported in the wood of T. cf. dumosa. Considering the climatic requirements of modern T. dumosa and P.armandii, the two species of conifer described from Pliocene sediments probably grew in mountainous terrain at an elevation of approximately 2 300 m, in a cool and humid environment.  相似文献   

8.
正近年来,食品安全、环境、生物制药、农业等产业问题频发,国家为此颁布了一系列的政策法规并对检测仪器提出了更多、更高的需求。同时,高质量需求也使企业更重视科学仪器的效率和准确性。而这些变化,让科学仪器市场的前景被看好。2016年10月10~12日,作为世界分析生化、诊断及实验室技术领域的盛  相似文献   

9.
Increasing terrestrial vegetation activity in China, 1982—1999   总被引:16,自引:0,他引:16  
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 accounted 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 exhibited 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.  相似文献   

10.
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 accounted 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 exhibited 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.  相似文献   

11.
Increasing terrestrial vegetation activity in China, 1982—1999   总被引:5,自引:0,他引:5  
The搊pening?policiesimplementedinChinainthepasttwodecadeshaveresultedinextensivechangesinlanduseandlandcover.Vegetationactivityhasincreasedthroughagriculturalpracticessuchasafforestation,irrigation,andintensiveagriculturalmanagement[1,2].Ontheotherhand,vegetationcover-agehasdecreasedduetorapidurbanization,industri-alization,andovergrazing[3,4].Thus,therearecon-flictingreportsregardingthestatusofChina抯vegeta-tion,asnointegrativeanalysisatthenationallevelhasyetbeenconducted.Thisstudyaimstoexpl…  相似文献   

12.
1. Lasiohelea aeschrodenta, sp. nov Female Head with eyes bare, AR 2.09;maxillary palp with a sensory pore on segment 3. Buccal armature has about 10 teeth which separated irregulary in the cibarium;clypeus with about 16 setae. Wing about 0.86 mm. long, with bare areas along veins. TR 1.74 in hind leg, with narrow scales on each tarsus. Spermatheca round and small, with abroad basical pore. Holotype:♀ Dukou, Sichuan, 1979 X. 10-11; Paratypes: 2♀♀Sichuan,Xichang, 1979 X. 5.  相似文献   

13.
A new species with two varieties,Meconopsis balangensis varieties balangensis and atrata (Papaveraceae),is described and characterized.Differences separating it from similar species are discussed and photos showing the diagnostic features are provided.  相似文献   

14.
Two new species of Meconopsis, M.pulchella and M.heterandra are described and characterized. Differences with similar species are discussed and photos showing the diagnostic features are provided.  相似文献   

15.
The paper deals with the new phaeophycean fossils in the Early Cambrian from Chengjiang Biota at Ercai Village of Haikou, Kunming, Yunnan, Southwest China. Three new taxa, Punctariopsis latifolia gen. et sp. nov., P.simplex gen. et sp. nov. and Vendotaenia cf. antiqua Gnilovskaya are described here in detail. These new findings show that the Chengjiang Biota is high in species diversity of fossil algae and might offer new evidence for a better understanding of the Cambrian explosive biological evolution. The fossil genus described here is found to have a close relationship with the living Punctaria based on similar morphology. The results suggest that the Chengjiang Biota in Haikou area of Kunming was living in an intertidal and subtidal seawater environment.  相似文献   

16.
To investigate the diversity of culturable actinobacteria and further screen for microbial pharmaceutics, seven different media were chosen to isolate actinobacteria from 87 soil samples collected from Qinghai–Tibet plateau. A total of 1930 strains was isolated and identified to belong to 11 suborders, i.e., Actinopolysporineae, Corynebacterineae, Frankineae, Glycomycineae, Kineosporiineae, Micrococcineae, Micromonosporineae, Propionibacterineae, Pseudonocardineae, Streptomycineae and Streptosporangineae, and 16 families, i.e., Nocardioidaceae, Actinopolysporaceae, Actinosynnemataceae, Dermacoccaceae, Geodermatophilaceae, Glycomycetaceae, Kineosporiaceae, Microbacteriaceae, Micromonosporaceae, Nocardiaceae, Promicromonosporaceae, Propionibacteriaceae, Pseudonocardiaceae, Streptomycetaceae, Streptosporangiaceae and Thermomonosporaceae. A primary taxonomic study showed that at least 22 genera of actinobacteria were identified from the soil samples, among which ten isolates represented hitherto unknown species. The results showed that there was abundant actinobacterial species diversity in the soil samples from the Qinghai–Tibet plateau.  相似文献   

17.
Paphiopedilum× yingjiangense Z . J . Liu et S . C . Chen , a new hybrid from China, is described and illustrated. This entity may be a natural hybrid between Paphiopedilum villosum and P . wardii . It differs from the former by having obscurely deep and light green nets on upper surface of leaves, a pale yellow-green flower with fine dark purple spots on petals and lower part of dorsal sepal and broadly ovate-orbicular staminode without a central glossy knob; from the latter by longer leaves not obviously mottled pale and dark bluish green above nor densely spotted purple below, a much larger flower, and a broadly ovate-orbicular staminode .  相似文献   

18.
Five species of higher marine fungi were observed on the incubated drift and intertidal woods collected from the coasts of Yellow Sea and Bohai Sea. Among them, Halosphaeriopsis was a genus newly recorded for China. Taxonomy and morphology of these species were discussed in this paper. The specimens were deposited in Mycology Herbarium at Qingdao Agricultural University (MHQAU).  相似文献   

19.

Objective

The aim of the study is to examine the spatiotemporal pattern of Japanese Encephalitis (JE) in mainland China during 2002–2010. Specific objectives of the study were to quantify the temporal variation in incidence of JE cases, to determine if clustering of JE cases exists, to detect high risk spatiotemporal clusters of JE cases and to provide evidence-based preventive suggestions to relevant stakeholders.

Methods

Monthly JE cases at the county level in mainland China during 2002–2010 were obtained from the China Information System for Diseases Control and Prevention (CISDCP). For the purpose of the analysis, JE case counts for nine years were aggregated into four temporal periods (2002; 2003–2005; 2006; and 2007–2010). Local Indicators of Spatial Association and spatial scan statistics were performed to detect and evaluate local high risk space-time clusters.

Results

JE incidence showed a decreasing trend from 2002 to 2005 but peaked in 2006, then fluctuated over the study period. Spatial cluster analysis detected high value clusters, mainly located in Southwestern China. Similarly, we identified a primary spatiotemporal cluster of JE in Southwestern China between July and August, with the geographical range of JE transmission increasing over the past years.

Conclusion

JE in China is geographically clustered and its spatial extent dynamically changed during the last nine years in mainland China. This indicates that risk factors for JE infection are likely to be spatially heterogeneous. The results may assist national and local health authorities in the development/refinement of a better preventive strategy and increase the effectiveness of public health interventions against JE transmission.  相似文献   

20.
Various factors can modify the health effects of temperature. Prior findings about modifiers are inconsistent, and such studies have been conducted mostly in developed countries. We conducted a time-series analysis to examine the modifying effect of gender, age and education on the association between temperature and daily mortality in Shanghai, China, using 4 years (2001–2004) of daily data. A natural spline model was used to analyze the data. Elderly subjects were found to be more vulnerable to temperature health effects compared with younger people. We observed no significant modifying effect of gender or education level. These findings may provide useful information for local governments seeking to take steps to protect vulnerable sub-populations.  相似文献   

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