Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Food Chem Toxicol ; 189: 114715, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38729342

RESUMO

As a commonly used food preservative, glycerol monocaprylate (GMC) has limited information and lacked a comprehensive risk assessment. In this study, we conducted in vitro genotoxicity tests, a 90-day subchronic toxicity study, and dietary exposure assessment in China. Rats (n = 10/sex/group) were orally administered GMC at doses of 1.02, 2.04, and 4.08 g/kg BW/day along with a water and corn oil for 90 days, including satellite groups (n = 5/sex/group) in the control groups and 4.08 g/kg BW dose group for observation after 90 days. Body weight, food consumption, hematology, serum biochemistry, urinalysis, endocrine hormone level and other metrics were examined. GMC did not exhibit genotoxicity based on the genotoxicity tests results, and an acceptable daily intake (ADI) of 40.8 mg/kg BW/day was established based on the 90-day subchronic toxicity study. Estimated daily intake of GMC for general population and consumer population in China were 0.99 mg/kg BW/day and 3.19 mg/kg BW/day respectively, which were significantly lower than the ADI. Our findings suggest that GMC does not pose a known health risk to Chinese consumers at the current usage level.


Assuntos
Glicerol , Ratos Sprague-Dawley , Animais , Masculino , Glicerol/toxicidade , Feminino , Ratos , Testes de Toxicidade Subcrônica , Testes de Mutagenicidade , Conservantes de Alimentos/toxicidade , Exposição Dietética , Peso Corporal/efeitos dos fármacos , China
2.
Environ Sci Ecotechnol ; 20: 100412, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38560759

RESUMO

Effective management of large basins necessitates pinpointing the spatial and temporal drivers of primary index exceedances and urban risk factors, offering crucial insights for basin administrators. Yet, comprehensive examinations of multiple pollutants within the Yangtze River Basin remain scarce. Here we introduce a pollution inventory for urban clusters surrounding the Yangtze River Basin, analyzing water quality data from 102 cities during 2018-2019. We assessed the exceedance rates for six pivotal indicators: dissolved oxygen (DO), ammonia nitrogen (NH3-N), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), and the permanganate index (CODMn) for each city. Employing random forest regression and SHapley Additive exPlanations (SHAP) analyses, we identified the spatiotemporal factors influencing these key indicators. Our results highlight agricultural activities as the primary contributors to the exceedance of all six indicators, thus pinpointing them as the leading pollution source in the basin. Additionally, forest coverage, livestock farming, chemical and pharmaceutical sectors, along with meteorological elements like precipitation and temperature, significantly impacted various indicators' exceedances. Furthermore, we delineate five core urban risk components through principal component analysis, which are (1) anthropogenic and industrial activities, (2) agricultural practices and forest extent, (3) climatic variables, (4) livestock rearing, and (5) principal polluting sectors. The cities were subsequently evaluated and categorized based on these risk components, incorporating policy interventions and administrative performance within each region. The comprehensive analysis advocates for a customized strategy in addressing the discerned risk factors, especially for cities presenting elevated risk levels.

3.
Foods ; 13(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38338497

RESUMO

The Yellow-Bohai Sea is an important semi-enclosed continental shelf marginal seas with an intensive aquaculture industry in China. The current study analyzed the contamination status and the time variations of paralytic shellfish toxins (PSTs) in shellfish between 2019 and 2020 from the Yellow-Bohai Sea in the Dalian area and estimated the acute health risks to consumers in China. A total of 199 shellfish samples (including 34 Pacific oysters, 25 Mediterranean blue mussels, 34 Manila clams, 36 bay scallops, 34 veined rapa whelks and 36 bloody clams) were analyzed from four representative aquaculture zones around the Yellow-Bohai Sea in Dalian. Among the samples, scallops and blood clams were the shellfish species with the highest detection rate of PSTs (94.4%), and the highest level of PSTs was detected in scallops with 3953.5 µg STX.2HCl eq./kg (µg STX.2HCL equivalents per kg shellfish tissue), followed by blood clams with 993.4 µg STX.2HCl eq./kg. The contents of PSTs in shellfish showed a time variation trend, and autumn was the season of concern for PST contamination in Dalian. For general Chinese consumers, the probability of acute health risks to shellfish consumers from dietary exposure to PSTs was around 13%. For typical consumers in coastal areas of China, especially those with higher shellfish intake, there was an acute health risk associated with exposure to PSTs through shellfish consumption during the occurrence of harmful algal blooms. It is suggested that the government continue to strengthen the monitoring of the source of PSTs and the monitoring of harmful algal blooms and give reasonable advice on shellfish consumption for consumers in coastal areas, such as not eating scallop viscera.

4.
J Environ Manage ; 354: 120388, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38382436

RESUMO

China has adopted a national carbon emissions trading market to promote emission reductions, but until now, overallocation of allowances suffer low carbon prices and thus to unfulfilled emission reduction goals. We report a general equilibrium modeling that indicates the flexible compliance and price adjustment mechanism of the carbon market, along with explores the solution to the oversupply of allowances in the China's national carbon market. We find that, under the current policy, the initial loose allowance allocation decreases the overall carbon price, and simultaneously the total amount of banked carbon allowances reaches 4.880 billion tons in 2030, resulting in the level of carbon price cannot achieve NDC (Nationally Determined Contribution) targets. However, by introducing carbon market price adjustment schemes, we observe that the cumulative amount of allowances can effectively reduce, enabling the carbon price rising. Importantly, the amount of the supply of allowances decreases most under the benchmark decrease scenario, which increases the emission reduction pressure of the enterprises from the beginning, leading to the largest economic losses, the price-based adjustment mechanism raises the carbon price to expected level at the minimize economic losses, and the quantity-based adjustment mechanism is more sensitive to policy parameters compared to the price -based adjustment mechanism. These findings offer a promising avenue for selecting cost-effective price adjustment mechanism to improve price mechanism design for national carbon markets.


Assuntos
Carbono , Políticas , Carbono/análise , China , Política Ambiental
5.
Sci Total Environ ; 913: 169739, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38163610

RESUMO

Microplastics (MPs) pollution in the marine environment has become a global problem. In this study, a number of 21 mollusk species (n = 2006) with different feeding habits were collected from 11 sites along the Bohai Sea for MPs uptake analysis. The MPs in mollusk samples were isolated and identified by micro-Fourier Transform Infrared Spectroscopy (µ-FTIR), and an assessment of the health risks of MPs ingested by mollusk consumption is also conducted. Approximately 91.9 % of the individuals among all the collected species inhaled MPs, and there was an average abundance of 3.30 ± 2.04 items·individual-1 or 1.04 ± 0.74 items·g-1 of wet weight. The shape of MPs was mainly fiber, and a total number of 8 polymers were detected, of which rayon had the highest detection rate (58.3 %). The highest abundance, uptake rate and polymer composition of MPs was observed in creeping types, suggesting that they might ingest these MPs from their food. The gastropod Siphonalia subdilatata contains the highest levels of MPs, which may increase the risk of human exposure if consumed whole without removing the digestive gland. The polymer risk level of MPs in these mollusks was Level III (H = 299), presenting harmful MPs such as polyvinyl chloride. In terms of human exposure risk, the average risk of human exposure to MPs through consumption of Bohai mollusks is estimated to be 3399 items·(capita·year)-1 (424-9349 items·(capita·year)-1). Overall, this study provides a basis for the ecological and health Risk assessment of MPs in mollusks collected from the coastline of China.


Assuntos
Gastrópodes , Poluentes Químicos da Água , Humanos , Animais , Microplásticos/análise , Plásticos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Moluscos , Medição de Risco
6.
Foods ; 12(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37297397

RESUMO

This study aimed to determine chemical composition and assess exposure in flavored milk among Chinese residents, based on risk assessment methodologies of acceptable daily intake (ADI) and toxicological concern threshold (TTC). Esters (32.17%), alcohols (11.19%), olefins (9.09%), aldehydes (8.39%), and ketones (7.34%) comprised the majority of the flavoring samples. Methyl palmitate (90.91%), ethyl butyrate (81.82%), and dipentene (81.82%) had the highest detection rates in flavor samples. This study screened fifteen flavor components of concern and discovered that 2,3,5-trimethylpyrazine, furfural, benzaldehyde, and benzenemethanol were detected in 100% of flavored milk samples. Benzenemethanol was found in the highest concentration (14,995.44 µg kg-1). The risk assessment results revealed that there was no risk for Chinese residents in consuming flavored milk, and the maximum per capita daily consumption of 2,3,5-trimethylpyrazine, furfural, and benzenemethanol were 226.208 g, 140.610 g, and 120.036 g, respectively. This study could provide guidelines for amounts of flavor additive ingredients in milk.

7.
J Hazard Mater ; 447: 130830, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36682248

RESUMO

4-n-nonylphenol (4-n-NP), a typical endocrine disrupting chemical, has been so far frequently detected in various environmental mediums and editable food. However, the specific metabolic pathways in human and potential adverse effects of metabolites have not been elucidated yet. Here, metabolic profiling of 4-n-NP in human liver microsome (HLM) was comprehensively characterized by integrated approaches of testing and assessment. A total of 21 metabolites were identified using nontarget analysis with high-resolution mass spectrum, including three groups of unique phase I metabolites first determined in HLM. Seven various metabolic pathways of 4-n-NP were identified by both in silico and in vitro, and CYP1A2, 2C19, and 2D6 were the mainly participating enzymes. Two secondary metabolites with carbonyl groups on side chains (M4, M7) presented most abundant in HLM, which were also predicted to have high binding affinities towards HPG-axis-related receptors (AR, ER, and PR). ESRs (estrogen receptors) were shared core protein targets for all metabolites revealed by protein-protein interaction networks. Biological functions enrichment analysis indicated that 4-n-NP metabolites might primarily involve in ESR-mediated signaling, GPCR ligand binding, Class A/1 (Rhodopsin-like receptors) and metabolism-related pathways. These findings of 4-n-NP metabolites, pathways, and biological effects provide insightful information for its environmental exposure and risk assessment.


Assuntos
Microssomos Hepáticos , Receptores Acoplados a Proteínas G , Humanos , Microssomos Hepáticos/metabolismo , Ligantes , Receptores Acoplados a Proteínas G/metabolismo , Fenóis/química
8.
Toxins (Basel) ; 14(8)2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-35893751

RESUMO

Deoxynivalenol (DON) and emerging Alternaria toxins often co-occur in cereal-based products, but the current risk assessment is commonly conducted for only one type of mycotoxin at a time. Compared to adults, infants and young children are more susceptible to mycotoxins through food consumption, especially with cereal-based food products which are the main source of exposure. This study aimed to perform a probabilistic risk assessment of combined exposure to DON and three major Alternaria toxins, namely including alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) through consumption of cereal-based foods for Chinese infants and young children. A total of 872 cereal-based food products were randomly collected and tested for the occurrence of DON and three major Alternaria toxins. The results on mycotoxin occurrence showed the DON, TeA, AOH, and AME was detected in 56.4%, 47.5%, 7.5%, and 5.7% of the samples, respectively. Co-contamination of various mycotoxins was observed in 39.9% of the analyzed samples. A preliminary cumulative risk assessment using the models of hazard index (HI) and combined margin of exposure (MoET) was performed on DON and Alternaria toxins that were present in cereal-based food products for infants and young children in China for the first time. The results showed that only 0.2% and 1.5%, respectively, of individuals exceeded the corresponding reference value for DON and TeA, indicating a low health risk. However, in the case of AME and AOH, the proportion of individuals exceeding the reference value was 24.1% and 33.5%, respectively, indicating the potential health risks. In the cumulative risk assessment of AME and AOH, both HI and MoET values indicated a more serious risk than that related to individual exposure. Further research is necessary to reduce the uncertainties that are associated with the toxicities of the Alternaria toxins and cumulative risk assessment methods.


Assuntos
Alternaria , Grão Comestível , Contaminação de Alimentos , Tricotecenos , Alternaria/isolamento & purificação , Pré-Escolar , China , Grão Comestível/química , Grão Comestível/microbiologia , Contaminação de Alimentos/análise , Humanos , Lactente , Lactonas/análise , Micotoxinas/análise , Medição de Risco , Ácido Tenuazônico/análise , Tricotecenos/análise
10.
Mycotoxin Res ; 36(4): 419-427, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829468

RESUMO

Deoxynivalenol (DON) is one of the most commonly found mycotoxins across the world, and it mainly contaminates staple food crops. This study aims to evaluate the dietary exposure of DON and to provide a geographical profile of DON exposure in China. The concentrations of DON and its acetylated derivatives in 15,004 cereal samples (10,192 wheat flour, 1750 maize meal, 892 oat flakes, and 2170 polished rice) were collected from 30 provinces, autonomous regions, or municipalities across China during 2010-2017, through a national food safety risk surveillance system. The consumption data for cereals were obtained from China National Nutrition and Health Survey in 2002, and 67,923 respondents from the same 30 regions were included in the analysis. Among all the cereals considered, the concentration was the highest in wheat flour, with the mean concentration of 250.8 µg/kg. Applying a worst-case scenario, some individuals were possibly at risk, but the probability of acute effects was low. The mean and median exposure for the entire population was 0.61 and 0.36 µg/kg bw/day, respectively, below the (PM) TDI, indicating an acceptable overall health risk in Chinese population. Wheat contributed to 86% of the total DON exposure. Significant discrepancy was observed between the exposure and the contamination of DON. The high-exposure cluster area was in northern China, whilst the most seriously contaminated regions were all located in the southeast, which formed a seriously contaminated area.


Assuntos
Exposição Ambiental/análise , Contaminação de Alimentos/análise , Micotoxinas/análise , Tricotecenos/análise , Acetilação , Adolescente , Adulto , Criança , Pré-Escolar , China , Exposição Dietética/análise , Grão Comestível , Análise de Perigos e Pontos Críticos de Controle , Humanos , Limite de Detecção , Pessoa de Meia-Idade , Vigilância da População , Vigilância em Saúde Pública , Medição de Risco , Tricotecenos/química , Adulto Jovem
11.
Artigo em Inglês | MEDLINE | ID: mdl-31100047

RESUMO

The aim of the study was to assess the dietary intake of caramel colours and their by-products 4-methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) for the Chinese population. Based on the typical and maximum reported use levels of caramel colours in 15 food categories, the dietary intakes of combined and single-class caramel colours of Classes I, III and IV were estimated with the food consumption data from the China National Nutrient and Health Survey. Using the mean values of 4-MEI and THI contents in Class III and Class IV Caramel colour samples, the exposures to 4-MEI and THI from dietary caramel colours were derived. The results showed that the combined and individual average dietary caramel colour intakes for the Chinese population of different age groups were estimated to be 232-60.3 mg kg-1 bw day-1 for combined caramels, 5.9-29.2 mg kg-1 bw day-1 for Class I, 7.7-29.6 mg kg-1 bw day-1 for Class III, 21.2-54.3 mg kg-1 bw day-1 for Class IV, which were far below the group acceptable daily intake (ADI) and respective ADIs. The combined intake of 4-MEI from Class III and IV caramel colours was estimated to be 3.8-5.2 µg kg-1 bw day-1 on average, and 12.9-27.1 µg kg-1 bw day-1 at 95th-97.5th percentile for the general population. The anticipated exposure to THI from Class III caramel colours was estimated to be 0.1-0.3 µg kg-1 bw day-1 on average and 0.5-1.7 µg kg-1 bw day-1 at 95th-97.5th percentile for the general population. The dietary caramel colours intakes and the exposures to 4-MEI and THI from dietary caramel colour for the Chinese population were considered to be of low health concern based on the present toxicological data. Soy sauce, vinegar and compound seasonings were found to be the main contributors to the dietary intake of caramel colours.


Assuntos
Carboidratos/análise , Exposição Dietética/análise , Corantes de Alimentos/análise , Imidazóis/análise , Adolescente , Adulto , Animais , Carboidratos/administração & dosagem , Criança , Pré-Escolar , Feminino , Análise de Alimentos , Corantes de Alimentos/administração & dosagem , Humanos , Imidazóis/administração & dosagem , Masculino , Pessoa de Meia-Idade , Ratos , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-30865572

RESUMO

The aim of this study was to assess the Al dietary exposure of young Chinese children aged 0-3 years via formulae, complementary foods and wheat-based foods. Al residue data were obtained from the national food contamination monitoring programme from 2013 to 2016, encompassing 13,833 samples of 12 food items with a detection rate of 76.0%. Food consumption data were gathered from the China National Food Consumption Survey conducted in 2015, comprising 20,172 children aged 0-3 years old. The mean dietary exposure to Al for the general population of young Chinese children was estimated at 0.76 mg/kg bw/week, which does not exceed the PTWI. The 97.5th percentile intakes of Al reached 3.42 mg/kg bw/week, more than 1.7 times the PTWI. Wheat-based foods contributed 80.5% of the Al intake for the general population of young Chinese children, while formulae and complementary foods accounted for 19.5% of the total intake. The dietary intake of Al from formulae and complementary foods accounted for 6.0% and 1.6% of PTWI, respectively. These findings suggested that dietary exposure to Al among the general population of young Chinese children was lower than the PTWI and that there are no health concerns related to this level of Al intake. However, more attention should be placed on the health risks associated with Al exposure from wheat-based foods for young consumers with high food consumption in China (97.5th percentile).


Assuntos
Alumínio/análise , Exposição Dietética/análise , Análise de Alimentos , Contaminação de Alimentos/análise , Alumínio/administração & dosagem , Pré-Escolar , Humanos , Lactente , Recém-Nascido
13.
J Food Sci ; 84(3): 701-710, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30730583

RESUMO

An investigation of the naturally occurring aluminum contents in grains, fruits and vegetables locally planted in some areas of China was conducted, and the aluminum dietary intake from the investigated food was estimated. A total of 2,469 samples were collected during 2013 to 2014 and tested for aluminum content using ICP-MS method. The results showed that although 77.6% of the samples contained aluminum less than 5 mg/kg, significant variations of aluminum contents were observed in different food groups. Generally, the aluminum contents were found to be relatively high in dried grains and fresh vegetables, and low in fresh fruits. The mean value of aluminum contents in grains was 6.3 mg/kg, with wheat being the highest, followed by soybean and corn. The fresh vegetables had an average aluminum content of 4.7 mg/kg, with leafy vegetables being the highest, followed by bulb and stem vegetables. Most varieties of fresh fruits were low in aluminum, with the mean of 1.3 mg/kg. Based on the food consumption data from the China National Nutrient and Health Survey, the average weekly dietary intake of naturally occurring aluminum from the investigated foods was estimated to be 0.62 mg/kg bw for the general population and 0.55 to 1.00 mg/kg bw for different age groups. Grains and vegetables were the main contributors to the overall intake. Evaluated against the provisional tolerable weekly intake (PTWI) of 2 mg/kg bw, the dietary naturally occurring aluminum intake from the investigated foods was considered to be no safety concern.


Assuntos
Alumínio/química , Fabaceae/química , Frutas/química , Verduras/química , Adolescente , Idoso , China , Dieta , Análise de Alimentos , Humanos , Masculino , Avaliação Nutricional
14.
Sci Rep ; 8(1): 3901, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29497102

RESUMO

A risk assessment of deoxynivalenol (DON) was recently conducted for the residents in Henan province, China, where wheat as the staple food are highly consumed. A high-throughput sensitive UPLC-MS/MS method following 96-well µElution solid-phase extraction (SPE) were developed and validated for the determination of DON biomarkers in human urine. Isotope labelled internal standard, 13C-DON, was used for accurate quantification. Urinary samples collected from 151 healthy Chinese aged 2-78 years were processed with and without enzyme hydrolysis to determine total and free biomarkers, respectively. DON, and de-epoxy-deoxynivalenol (DOM-1) to a lesser extent, can be frequently detected in these samples both with and without enzyme hydrolysis. Free DOM-1 was detected at low level in human urine for the first time. Total DON was detected in all samples with a mean concentration at 47.6 ng mL-1. The mean and median probable daily intakes (PDI) for the whole participants, estimated to be 1.61 µg/kg bw and 1.10 µg/kg bw, both exceeded the PMTDI (1 µg/kg bw/day), indicating a potential risk for the residents in this area, especially for children and adolescents.


Assuntos
Monitoramento Ambiental/métodos , Medição de Risco/métodos , Tricotecenos/análise , Adolescente , Adulto , Idoso , Biomarcadores/urina , Criança , Pré-Escolar , China , Cromatografia Líquida/métodos , Exposição Ambiental/análise , Feminino , Contaminação de Alimentos/análise , Ensaios de Triagem em Larga Escala/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Micotoxinas/análise , Fatores de Risco , Espectrometria de Massas em Tandem/métodos , Tricotecenos/química , Tricotecenos/urina , Triticum/química
15.
Int Psychogeriatr ; 30(8): 1131-1138, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29223171

RESUMO

ABSTRACTBackground:Very few recent studies are available that compare caregiver burden, sleep quality, and stress in caregivers of different types of dementia. We aimed to investigate caregiver burden, sleep quality, and stress in caregivers of patients with frontotemporal lobar degeneration and dementia with Lewy bodies, as compared with caregivers of patients with Alzheimer's disease. METHODS: This study was carried out from March 2011 to January 2014. In total, 492 dyads of patient and caregiver (frontotemporal lobar degeneration, n = 131; dementia with Lewy bodies, n = 36; Alzheimer's disease, n = 325) participated in this study. We compared patients with respect to the Neuropsychiatric Inventory and caregivers with respect to the Zarit Caregiver Burden Interview, Pittsburgh Sleep Quality Index, Patient Health Questionnaire-9, and Generalized Anxiety Disorder scale. RESULTS: Frontotemporal lobar degeneration and dementia with Lewy bodies patients presented significantly more neuropsychiatric symptoms compared to Alzheimer's disease patients. Caregivers of frontotemporal lobar degeneration and dementia with Lewy bodies patients experienced significantly more burden compared to Alzheimer's disease caregivers. Furthermore, among caregivers of both frontotemporal lobar degeneration and dementia with Lewy bodies patients burden was predicted by the neuropsychiatric symptoms, PHQ-9 scores, and GAD-7 scores. CONCLUSIONS: The frequency and severity of behavioral disturbances in patient and caregiver stress accounted for the increased caregiver burden, which suggests that frontotemporal lobar degeneration and dementia with Lewy bodies caregivers should receive more support than is currently available.


Assuntos
Doença de Alzheimer/psicologia , Ansiedade/diagnóstico , Cuidadores/psicologia , Depressão/diagnóstico , Degeneração Lobar Frontotemporal/psicologia , Doença por Corpos de Lewy/psicologia , Sono , Adaptação Psicológica , Idoso , Idoso de 80 Anos ou mais , China , Cognição , Efeitos Psicossociais da Doença , Feminino , Humanos , Modelos Logísticos , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
16.
J Environ Qual ; 41(5): 1393-401, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23099930

RESUMO

Eco-environmental quality assessment (EQA) is an intricate and challenging task that must take into account numerous natural, economic, political, and social factors, which are subject to multiple conflicting criteria. In this paper, a methodological reference framework is developed for EQA that combines the fuzzy Delphi method (FDM) and fuzzy analytical hierarchy process (FAHP) with a geographic information system (GIS). The proposed method significantly improves the accuracy and reliability of evaluation results through the incorporation of fuzzy set theory. A GIS not only has the ability to store and analyze large amounts of spatial data from different sources but also provides a consistent visualization environment for displaying the input data and the results of EQA. Furthermore, unlike prior EQAs, the proposed method can support the dynamic estimation of regional eco-environmental quality by updating historical spatiotemporal data at little additional cost. A case study is presented for the western Tibetan Plateau. The study results show that worse, bad, and moderate eco-environmental quality classes comprised 16.58, 20.15, and 24.84% of the total area, respectively. Good and better eco-environmental quality classes accounted for 38.43%. This result indicates that nearly 62% of the total area is eco-environmentally vulnerable. The results verified the usefulness and feasibility of the proposed method. The EQA can also help local managers make scientifically based and effective decisions about Tibetan eco-environmental protection and land use.


Assuntos
Meio Ambiente , Algoritmos , Técnica Delphi , Ecologia/métodos , Lógica Fuzzy , Sistemas de Informação Geográfica , Tibet
17.
Sci China Life Sci ; 54(11): 1042-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22173311

RESUMO

The rapid growth of the global HIV/AIDS epidemic makes it a high priority to develop an effective vaccine. Since a live attenuated or inactivated HIV vaccine is not likely to be approved for clinical application due to safety concerns, HIV virus like particles (VLPs) offer an attractive alternative because they are considered safer since they lack viral genome. We got a stable eukaryotic cell line by G418 resistance selection, engineered to express the HIV-1 structure protein Gag and Env efficiently and stably. We confirmed the presence of Gag and Env proteins in the cell culture supernatant and that they could self-assemble into VLPs. These VLPs were found to be able to elicit specific humoral and cellular immune response after immunization without any adjuvant.


Assuntos
Vacinas contra a AIDS/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Vírion/imunologia , Animais , Linhagem Celular , Feminino , Produtos do Gene env/genética , Produtos do Gene env/imunologia , Produtos do Gene gag/genética , Produtos do Gene gag/imunologia , Células HEK293 , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/imunologia , HIV-1/genética , HIV-1/ultraestrutura , Humanos , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Citotóxicos/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vírion/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA