Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large...Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large number of soils are nowadays contaminated over widespread areas, posing a great threat to public health worldwide. Unlike organic pollutants, Pb and Cd do not undergo chemical or microbial breakdown and stay likely in site for longer duration after their release. Immobilization is an in-situ remediation technique that uses cost-effective soil amendments to reduce Pb and Cd availability in the contaminated soils. The Pb and Cd contamination in the soil environment is reviewed with focus on source enrichment, speciation and associated health risks, and immobilization options using various soil amendments. Commonly applied and emerging cost-effective soil amendments for Pb and Cd immobilization include phosphate compounds, liming, animal manure, biosolids, metal oxides, and biochar. These immobilizing agents could reduce the transfer of metal pollutants or residues to food web(plant uptake and leaching to subsurface water) and their long-term sustainability in heavy metal fixation needs further assessment.展开更多
Ten hepatitis B virus （HBV） genotypes （A-J） and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard t...Ten hepatitis B virus （HBV） genotypes （A-J） and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C （C2） is more frequently associated with an increased risk of hepatocellular carcinoma （HCC）, mostly cirrhotic, as compared with genotype B （B2）. Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 （G145R）, are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhH/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC- associated HBV mutants may not transmit via motherto-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic suscep-tibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active antiviral treatments.展开更多
Objective To review HIV/AIDS epidemic history, current situation and prevention policy in China. Data sources Information included in this article was identified by searching PUBMED （1997-2006） online resources usin...Objective To review HIV/AIDS epidemic history, current situation and prevention policy in China. Data sources Information included in this article was identified by searching PUBMED （1997-2006） online resources using the key terms ＂HIV/AIDS＂, ＂epidemic＂, ＂prevention＂, and ＂China＂. Study selection Original milestone articles and critical reviews written by major pioneer investigators of the field were selected. Results The key issues related to the HIV/AIDS epidemic situation in China and Chinese government prevention policy were summarized. HIV/AIDS epidemic groups and trends for HIV transmission were discussed. Conclusion In January 2006, 650 000 people were estimated to be living with HIV in China. The overall HIV/AIDS epidemic is at a low level （0.05%） and concentrated in several at risk populations. However, the data show that new cases of HIV infection are growing every year and spreading from at risk populations to the general population. Premier WEN Jia-bao announced the ＂Four frees and one care＂ policy and the Chinese government has developed a series of programs with strong policy measures to stop the spread of HIV/AIDS in China.展开更多
This paper considers the issue of local ＂land finance＇＂ in the context of China ＂s fast urban expansion. In an analysis of China ＂s land requisition and public leasing system we argue that low-cost land acquisiti...This paper considers the issue of local ＂land finance＇＂ in the context of China ＂s fast urban expansion. In an analysis of China ＂s land requisition and public leasing system we argue that low-cost land acquisition is the fundamental cause of land-related distortions that have occurred during China ＂s urbanization. Granting farmers the power to negotiate directly with land users during urban expansion, combined with coordinated land tax reforms to consolidate local tax bases is the key to China achieving both equity and land use efficiency in urban expansion.展开更多
文摘Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large number of soils are nowadays contaminated over widespread areas, posing a great threat to public health worldwide. Unlike organic pollutants, Pb and Cd do not undergo chemical or microbial breakdown and stay likely in site for longer duration after their release. Immobilization is an in-situ remediation technique that uses cost-effective soil amendments to reduce Pb and Cd availability in the contaminated soils. The Pb and Cd contamination in the soil environment is reviewed with focus on source enrichment, speciation and associated health risks, and immobilization options using various soil amendments. Commonly applied and emerging cost-effective soil amendments for Pb and Cd immobilization include phosphate compounds, liming, animal manure, biosolids, metal oxides, and biochar. These immobilizing agents could reduce the transfer of metal pollutants or residues to food web(plant uptake and leaching to subsurface water) and their long-term sustainability in heavy metal fixation needs further assessment.
基金Supported by Ministry of Health of China,No.2008ZX10002-15National Natural Science Foundation of China,No.30921006+2 种基金Shanghai Science & Technology Committee,No.08XD14001Shanghai Board of Health,No.08GWD0208GWZX0201
文摘Ten hepatitis B virus （HBV） genotypes （A-J） and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C （C2） is more frequently associated with an increased risk of hepatocellular carcinoma （HCC）, mostly cirrhotic, as compared with genotype B （B2）. Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 （G145R）, are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhH/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC- associated HBV mutants may not transmit via motherto-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic suscep-tibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active antiviral treatments.
文摘Objective To review HIV/AIDS epidemic history, current situation and prevention policy in China. Data sources Information included in this article was identified by searching PUBMED （1997-2006） online resources using the key terms ＂HIV/AIDS＂, ＂epidemic＂, ＂prevention＂, and ＂China＂. Study selection Original milestone articles and critical reviews written by major pioneer investigators of the field were selected. Results The key issues related to the HIV/AIDS epidemic situation in China and Chinese government prevention policy were summarized. HIV/AIDS epidemic groups and trends for HIV transmission were discussed. Conclusion In January 2006, 650 000 people were estimated to be living with HIV in China. The overall HIV/AIDS epidemic is at a low level （0.05%） and concentrated in several at risk populations. However, the data show that new cases of HIV infection are growing every year and spreading from at risk populations to the general population. Premier WEN Jia-bao announced the ＂Four frees and one care＂ policy and the Chinese government has developed a series of programs with strong policy measures to stop the spread of HIV/AIDS in China.
基金the Chinese Ministry of Science and Technology Key Technologies R&D Program (2006BAJ11B06)the China National Science Foundation (70633002)the Lincoln Institute for Land Policy for financial support
文摘This paper considers the issue of local ＂land finance＇＂ in the context of China ＂s fast urban expansion. In an analysis of China ＂s land requisition and public leasing system we argue that low-cost land acquisition is the fundamental cause of land-related distortions that have occurred during China ＂s urbanization. Granting farmers the power to negotiate directly with land users during urban expansion, combined with coordinated land tax reforms to consolidate local tax bases is the key to China achieving both equity and land use efficiency in urban expansion.
