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1.
ACS Cent Sci ; 5(11): 1857-1865, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31807687

RESUMO

Two-dimensional (2D) hybrid perovskite sandwiched between two long-chain organic layers is an emerging class of low-cost semiconductor materials with unique optical properties and improved moisture stability. Unlike conventional semiconductors, ion migration in perovskite is a unique phenomenon possibly responsible for long carrier lifetime, current-voltage hysteresis, and low-frequency giant dielectric response. While there are many studies of ion migration in bulk hybrid perovskite, not much is known for its 2D counterparts, especially for ion migration induced by light excitation. Here, we construct an exfoliated 2D perovskite/carbon nanotube (CNT) heterostructure field effect transistor (FET), not only to demonstrate its potential in photomemory applications, but also to study the light induced ion migration mechanisms. We show that the FET I-V characteristic curve can be regulated by light and shows two opposite trends under different CNT oxygen doping conditions. Our temperature-dependent study indicates that the change in the I-V curve is probably caused by ion redistribution in the 2D hybrid perovskite. The first principle calculation shows the reduction of the migration barrier of I vacancy under light excitation. The device simulation shows that the increase of 2D hybrid perovskite dielectric constant (enabled by the increased ion migration) can change the I-V curve in the trends observed experimentally. Finally, the so synthesized FET shows the multilevel photomemory function. Our work shows that not only we could understand the unique ion migration behavior in 2D hybrid perovskite, it might also be used for many future memory function related applications not realizable in traditional semiconductors.

2.
Inorg Chem ; 58(11): 7426-7432, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31091094

RESUMO

Two perovskite-type compounds, (MA)2[B'Co(CN)6] (MA = methylammonium, B' = K(I) and Na(I)), have very similar structures, but exhibit marked differences in the phase and dielectric transitions. Solid state 2H NMR studies reveal the detailed dynamic changes of the caged methylammonium (MA) cations before and after the phase transitions, which are correlated with the different dielectric states of the compounds. Using solid state 59Co NMR, the dynamic changes of the host lattices before and after the transitions, which accompany the changes in the dynamics of the caged MA cations, are unveiled, demonstrating the intriguing interplay between the MA cations and the host lattices. On the basis of these observations, the molecular origins of the dielectric transitions are discussed in detail.

3.
Viruses ; 7(1): 333-51, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25609306

RESUMO

Hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses and transmitted by rodents is a significant public health problem in China, and occurs more frequently in selenium-deficient regions. To study the role of selenium concentration in HFRS incidence we used a multidisciplinary approach combining ecological analysis with preliminary experimental data. The incidence of HFRS in humans was about six times higher in severe selenium-deficient and double in moderate deficient areas compared to non-deficient areas. This association became statistically stronger after correction for other significant environment-related factors (low elevation, few grasslands, or an abundance of forests) and was independent of geographical scale by separate analyses for different climate regions. A case-control study of HFRS patients admitted to the hospital revealed increased activity and plasma levels of selenium binding proteins while selenium supplementation in vitro decreased viral replication in an endothelial cell model after infection with a low multiplicity of infection (MOI). Viral replication with a higher MOI was not affected by selenium supplementation. Our findings indicate that selenium deficiency may contribute to an increased prevalence of hantavirus infections in both humans and rodents. Future studies are needed to further examine the exact mechanism behind this observation before selenium supplementation in deficient areas could be implemented for HFRS prevention.


Assuntos
Infecções por Hantavirus/epidemiologia , Infecções por Hantavirus/veterinária , Selênio/deficiência , Animais , Estudos de Casos e Controles , China , Células Endoteliais/virologia , Feminino , Hantavirus/crescimento & desenvolvimento , Humanos , Incidência , Masculino , Roedores
4.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 6): o665, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24940247

RESUMO

In the title compound, C18H22O4, the cyclo-hexane and cyclo-hexa-none rings adopt normal chair and half-chair conformations, respectively. The dioxolane ring is almost planar, with an r.m.s. deviation of 0.094 (3) Å. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds, forming 21 helical chains along the a-axis direction. The chains are further connected by C-H⋯O hydrogen bonds.

5.
Biomed Environ Sci ; 25(6): 645-52, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23228834

RESUMO

OBJECTIVE: To identify patterns of hand, foot and mouth disease (HFMD) incidence in China during declining incidence periods of 2008, 2009, and 2010. METHODS: Reported HFMD cases over a period of 25 months were extracted from the National Disease Reporting System (NDRS) and analyzed. An interrupted time series (ITS) technique was used to detect changes in HFMD incidence rates in terms of level and slope between declining incidence periods of the three years. RESULTS: Over 3.58 million HFMD cases younger than 5 years were reported to the NDRS between May 1, 2008, and May 31, 2011. Males comprised 63.4% of the cases. ITS analyses demonstrated a significant increase in incidence rate level (P<0.0001) when comparing the current period with the previous period. There were significant changes in declining slopes when comparing 2010 to 2009, and 2010 to 2008 (all P<0.005), but not 2009 to 2008. CONCLUSION: Incremental changes in incidence rate level during the declining incidence periods of 2009 and 2010 can potentially be attributed to a few factors. The more steeply declining slope in 2010 compared with previous years could be ascribed to the implementation of more effective interventions and preventive strategies in 2010. Further investigation is required to examine this possibility.


Assuntos
Doença de Mão, Pé e Boca/epidemiologia , China/epidemiologia , Feminino , Humanos , Incidência , Masculino , Modelos Estatísticos , Vigilância da População , Fatores de Tempo
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 33(8): 808-12, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-22967334

RESUMO

OBJECTIVE: The purpose of this study was to explore the spatial clustering, specific clustering areas, as well as changing trend of clustering areas of hand-foot-mouth disease (HFMD). METHODS: Exploratory spatial data analysis (ESDA) was used to conduct spatial statistical analyses for the HFMD using 2008 - 2011 data at both provincial and county/district levels. RESULTS: The Global Moran's I coefficients appeared to be 0.3336, 0.6074, 0.3372, 0.4620 and 0.4367 for 2008 - 2011 and for the combined 4 years, respectively. The corresponding P-values were 0.002, 0.001, 0.004, 0.001 and 0.001 respectively, when using the Monte Carlo tests with all the P-values less than 0.05. Moran's I coefficients ranged between 0.3 and 0.7, showing the appearance of moderate or higher clustering nature. Based on the results from nationwide analyses on clustering areas at the county/district levels between 2008 and 2011 (Moran's I = 0.5198, P = 0.001), it appeared a moderate clustering nature. When local autocorrelation analysis was applied at the provincial level, 3 hot spot areas in Beijing, Tianjin and Shanghai cities in 2008; 7 hot spot areas in Beijing, Tianjin, Hebei, Shanxi, Shanghai, Jiangsu and Shandong in 2009; four hot spot areas: Beijing, Tianjin, Guangdong and Guangxi; five hot spot areas: Fujian, Jiangxi, Hunan, Guangdong and Guangxi in 2011, were discovered. 390 hot-spot counties/districts were found through local autocorrelation analyses using the three-year data of 2008 to 2010. CONCLUSION: Spatial clustering nature of HFMD incidence between 2008 and 2011 in China appeared to be moderate or high, with the clustered areas a north to south shifting trend. However, further investigation was in need to address this changing trend.


Assuntos
Análise por Conglomerados , Doença de Mão, Pé e Boca/epidemiologia , China/epidemiologia , Humanos , Incidência , Método de Monte Carlo
7.
PLoS One ; 7(8): e43686, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22928015

RESUMO

Malaria is re-emerging in Anhui Province, China after a decade long' low level of endemicity. The number of human cases has increased rapidly since 2000 and reached its peak in 2006. That year, the malaria cases accounted for 54.5% of total cases in mainland China. However, the spatial and temporal patterns of human cases and factors underlying the re-emergence remain unclear. We established a database containing 20 years' (1990-2009) records of monthly reported malaria cases and meteorological parameters. Spearman correlations were used to assess the crude association between malaria incidence and meteorological variables, and a polynomial distributed lag (PDL) time-series regression was performed to examine contribution of meteorological factors to malaria transmission in three geographic regions (northern, mid and southern Anhui Province), respectively. Then, a two-year (2008-2009) prediction was performed to validate the PDL model that was created by using the data collected from 1990 to 2007. We found that malaria incidence decreased in Anhui Province in 1990s. However, the incidence has dramatically increased in the north since 2000, while the transmission has remained at a relatively low level in the mid and south. Spearman correlation analyses showed that the monthly incidences of malaria were significantly associated with temperature, rainfall, relative humidity, and the multivariate El Niño/Southern Oscillation index with lags of 0-2 months in all three regions. The PDL model revealed that only rainfall with a 1-2 month lag was significantly associated with malaria incidence in all three regions. The model validation showed a high accuracy for the prediction of monthly incidence over a 2-year predictive period. Malaria epidemics showed a high spatial heterogeneity in Anhui Province during the 1990-2009 study periods. The change in rainfall drives the reemergence of malaria in the northern Anhui Province.


Assuntos
Malária/epidemiologia , Chuva , China/epidemiologia , Monitoramento Epidemiológico , Humanos , Malária/transmissão , Modelos Estatísticos , Análise Espaço-Temporal
8.
Am J Epidemiol ; 175(9): 890-7, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22491083

RESUMO

Data from all reported cases of 2009 pandemic influenza A (H1N1) were obtained from the China Information System for Disease Control and Prevention. The spatiotemporal distribution patterns of cases were characterized through spatial analysis. The impact of travel-related risk factors on invasion of the disease was analyzed using survival analysis, and climatic factors related to local transmission were identified using multilevel Poisson regression, both at the county level. The results showed that the epidemic spanned a large geographic area, with the most affected areas being in western China. Significant differences in incidence were found among age groups, with incidences peaking in school-age children. Overall, the epidemic spread from southeast to northwest. Proximity to airports and being intersected by national highways or freeways but not railways were variables associated with the presence of the disease in a county. Lower temperature and lower relative humidity were the climatic factors facilitating local transmission after correction for the effects of school summer vacation and public holidays, as well as population density and the density of medical facilities. These findings indicate that interventions focused on domestic travel, population density, and climatic factors could play a role in mitigating the public health impact of future influenza pandemics.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Pandemias , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
9.
Biomed Environ Sci ; 24(4): 349-56, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22108323

RESUMO

OBJECTIVE: Since HFMD was designated as a class C communicable disease in May 2008, 18 months surveillance data have been accumulated to December 2009. This article was to describe the distribution of HFMD for age, sex, area, and time between 2008 and 2009, to reveal the characteristics of the epidemic. METHODS: We analyzed weekly reported cases of HFMD from May 2008 to December 2009, and presented data on the distribution of age, sex, area and time. A discrete Poisson model was used to detect spatial-temporal clusters of HFMD. RESULTS: More than 1 065 000 cases of HFMD were reported in Mainland China from May 2008 to December 2009 (total incidence: 12.47 per 10 000). Male incidence was higher than female for all ages and 91.9% of patients were <5 years old. The incidence was highest in Beijing, Shanghai, Zhejiang and Hainan. The highest peak of HFMD cases was in April and the number of cases remained high from April to August. The spatial-temporal distribution detected four clusters. CONCLUSION: Children <5 years old were susceptible to HFMD and we should be aware of their vulnerability. The incidence was higher in urban than rural areas, and an annual pandemic usually starts in April.


Assuntos
Doença de Mão, Pé e Boca/epidemiologia , Envelhecimento , Pré-Escolar , China/epidemiologia , Análise por Conglomerados , Feminino , Humanos , Incidência , Lactente , Masculino , Caracteres Sexuais , Fatores de Tempo
10.
Clin Infect Dis ; 52(12): 1414-21, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21628481

RESUMO

BACKGROUND: Differences between male and female individuals in response to infectious diseases are an overlooked global health problem. METHODS: The relationship between sex and disease outcome was examined in populations of patients with hemorrhagic fever with renal syndrome (HFRS) in mainland China, where most cases of hantavirus exposure occur. HFRS in China is diagnosed on the basis of symptoms and is confirmed with serological testing. The geographical distribution, incidence, and case fatality rates (CFRs) of HFRS in China were estimated and compared by patient sex and age. In a subset of patients with HFRS, clinical manifestations of HFRS were assessed using latent class analysis and compared by sex. RESULTS: There were 80,671 HFRS cases reported during the period 2004-2008, with a majority of HFRS cases (39.2%) occurring among individuals 20-39 years of age. The incidence of HFRS was higher among male patients than among female patients for all individuals >10 years of age. There were 945 deaths (CFR, 1.17%) due to HFRS in China during the period 2004-2008. CFRs were higher among women than among men between the ages of 20-39 and ≥ 50 years of age. There were no sex differences in the geographical distribution of HFRS cases or deaths. Although the prevalence of each clinical marker did not differ by sex, 2 profiles of clinical markers were identified that were related to both severity of disease and sex. CONCLUSIONS: These data illustrate a paradox in which the incidence of disease is greater for males, but the severity of disease outcome is worse for females. Several behavioral, societal, and biological factors are hypothesized to be involved.


Assuntos
Hantavirus/isolamento & purificação , Hantavirus/patogenicidade , Febre Hemorrágica com Síndrome Renal/epidemiologia , Febre Hemorrágica com Síndrome Renal/mortalidade , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Feminino , Geografia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mortalidade , Fatores de Risco , Fatores Sexuais , Adulto Jovem
11.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(5): 431-5, 2011 May.
Artigo em Chinês | MEDLINE | ID: mdl-21569720

RESUMO

OBJECTIVE: To analyze the results of application on China Infectious Diseases Automated-alert and Response System (CIDARS) and for further improving the system. METHODS: Amount of signal, proportion of signal responded, time to signal response, manner of signal verification and the outcome of each signal in CIDARS were descriptively analyzed from July 1, 2008 to June 30, 2010. RESULTS: A total of 533 829 signals were generated nationwide on 28 kinds of infectious diseases in the system. 97.13% of the signals had been responded and the median time to response was 1.1 hours. Among them, 2472 signals were generated by the fixed-value detection method which involved 9 kinds of diseases after the preliminary verification, field investigation and laboratory tests. 2202 signals were excluded, and finally 246 cholera cases, 15 plague cases and 9 H5N1 cases as well as 39 outbreaks of cholera were confirmed. 531 357 signals were generated by the other method - the 'moving percentile method' which involved 19 kinds of diseases. The average amount of signal per county per week was 1.65, with 6603 signals (1.24%) preliminarily verified as suspected outbreaks and 1594 outbreaks were finally confirmed by further field investigation. For diseases in CIDARS, the proportion of signals related to suspected outbreaks to all triggered signals showed a positive correlation with the proportion of cases related to outbreaks of all the reported cases (r = 0.963, P < 0.01). CONCLUSION: The signals of CIDARS were responded timely, and the signal could act as a clue for potential outbreaks, which helped enhancing the ability on outbreaks detection for local public health departments.


Assuntos
Controle de Doenças Transmissíveis , Processamento Eletrônico de Dados , Vigilância da População , China , Notificação de Doenças , Humanos , Saúde Pública
12.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(5): 436-41, 2011 May.
Artigo em Chinês | MEDLINE | ID: mdl-21569721

RESUMO

OBJECTIVE: To analyze the pilot results of both temporal and temporal-spatial models in outbreaks detection in China Infectious Diseases Automated-alert and Response System (CIDARS) to further improve the system. METHODS: The amount of signal, sensitivity, false alarm rate and time to detection regarding these two models of CIDARS, were analyzed from December 6, 2009 to December 5, 2010 in 221 pilot counties of 20 provinces. RESULTS: The sensitivity of these two models was equal (both 98.15%). However, when comparing to the temporal model, the temporal-spatial model had a 59.86% reduction on the signals (15 702) while the false alarm rate of the temporal-spatial model (0.73%) was lower than the temporal model (1.79%), and the time to detection of the temporal-spatial model (0 day) was also 1 day shorter than the temporal model. CONCLUSION: Comparing to the temporal model, the temporal-spatial model of CIDARS seemed to be better performed on outbreak detection.


Assuntos
Doenças Transmissíveis/epidemiologia , Surtos de Doenças , Vigilância da População/métodos , China , Notificação de Doenças , Humanos , Modelos Teóricos , Análise Espaço-Temporal
13.
PLoS Negl Trop Dis ; 5(1): e945, 2011 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-21264354

RESUMO

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is highly endemic in mainland China, and has extended from rural areas to cities recently. Beijing metropolis is a novel affected region, where the HFRS incidence seems to be diverse from place to place. METHODOLOGY/PRINCIPAL FINDINGS: The spatial scan analysis based on geographical information system (GIS) identified three geo-spatial "hotspots" of HFRS in Beijing when the passive surveillance data from 2004 to 2006 were used. The Relative Risk (RR) of the three "hotspots" was 5.45, 3.57 and 3.30, respectively. The Phylogenetic analysis based on entire coding region sequence of S segment and partial L segment sequence of Seoul virus (SEOV) revealed that the SEOV strains circulating in Beijing could be classified into at least three lineages regardless of their host origins. Two potential recombination events that happened in lineage #1 were detected and supported by comparative phylogenetic analysis. The SEOV strains in different lineages and strains with distinct special amino acid substitutions for N protein were partially associated with different spatial clustered areas of HFRS. CONCLUSION/SIGNIFICANCE: Hotspots of HFRS were found in Beijing, a novel endemic region, where intervention should be enhanced. Our data suggested that the genetic variation and recombination of SEOV strains was related to the high risk areas of HFRS, which merited further investigation.


Assuntos
Doenças Endêmicas , Febre Hemorrágica com Síndrome Renal/epidemiologia , Febre Hemorrágica com Síndrome Renal/virologia , Vírus Seoul/classificação , Vírus Seoul/genética , Animais , China/epidemiologia , Análise por Conglomerados , Genótipo , Humanos , Filogenia , RNA Viral/genética , Recombinação Genética , Vírus Seoul/isolamento & purificação , Análise de Sequência de DNA , Homologia de Sequência , População Urbana , Proteínas Virais/genética
14.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(12): 1278-84, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22336617

RESUMO

Based on data related to human brucellosis which was collected from the national notifiable infectious disease reporting system in the 6 provinces (Inner Mongolia, Shanxi, Heilongjiang, Shaanxi, Jilin and Liaoning) of north China from 2004 to 2007, at the county scale. Data would include age and gender standardized mortality ratios (SMRs) while ESDA was including histograms, box plots and box maps, global and local Moran's I statistics, etc. The global Moran's I values from 2004 to 2007 were 0.2581, 0.4574, 0.4457, 0.4841, respectively and all with statistically significant differences. Most of local Moran's I values were significant positive statistically. High-high counties were mainly in the northeast, most of which were pastoral areas, but the farming-pastoral areas and agricultural areas/town had an increasing trend over time. Low-low counties were mainly in the western and southern areas and most of which were agricultural areas/towns. Low-high counties appeared to be rare, mainly around the counties with high incidence, mainly belonged to agricultural areas/towns. The incidence rates of brucellosis in the six provinces of north China had a trend of increase from 2004 to 2007, namely spreading from east to west, from south to north, and from pastoral areas to farming-pastoral areas and agricultural areas/towns. ESDA could be used to develop effective measures for prevention and control of brucellosis.


Assuntos
Brucelose/epidemiologia , Análise Espacial , China/epidemiologia , Feminino , Humanos , Masculino
16.
Zhongguo Yi Miao He Mian Yi ; 16(3): 233-7, 2010 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-20726265

RESUMO

OBJECTIVE: To analyze the daily data of epidemic Mumps in a province from 2004 to 2008 and set up exponential smoothing model for the prediction. METHODS: To predict and warn the epidemic mumps in 2008 through calculating 7-day moving summation and removing the effect of weekends to the data of daily reported mumps cases during 2005-2008 and exponential summation to the data from 2005 to 2007. RESULTS: The performance of Holt-Winters exponential smoothing is good. The result of warning sensitivity was 76.92%, specificity was 83.33%, and timely rate was 80%. CONCLUSIONS: It is practicable to use exponential smoothing method to warn against epidemic Mumps.


Assuntos
Surtos de Doenças , Métodos Epidemiológicos , Caxumba/epidemiologia , China/epidemiologia , Notificação de Doenças , Humanos , Valor Preditivo dos Testes , Estações do Ano
17.
Emerg Infect Dis ; 15(12): 2043-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19961697

RESUMO

We used geographic information systems to characterize the dynamic change in spatial distribution of hemorrhagic fever with renal syndrome (HFRS) in Beijing, People's Republic of China. The seasonal variation in its incidence was observed by creating an epidemic curve. HFRS was associated with developed land, orchards, and rice paddies.


Assuntos
Febre Hemorrágica com Síndrome Renal/epidemiologia , China/epidemiologia , Sistemas de Informação Geográfica , Humanos , Incidência , Estações do Ano
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 30(1): 38-41, 2009 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-19565846

RESUMO

OBJECTIVE: To analyze the determinants of malaria in Anhui province during the year of 2004-2006. METHODS: A GIS-based database of malaria at the township scale of Anhui province was established, using remote sensing and spatial analysis technologies. Methods on statistical analysis, principal component analysis combined with logistic regression analysis were synthetically used to analyze the association between malaria and environmental factors. RESULTS: Malaria epidemics in Anhui province during 2004-2006 mainly occurred in the northern districts of Huai River, and the epidemics had become more serious yearly. The determinants of malaria at the township scale mainly included factors as temperature, rainfall, normalized difference vegetable index and elevation. If the lowest temperature in a year, which appeared the fourth principal component of the temperature index series, increased by one unit, the probability of incidence of malaria would decrease by 33%. If the total annual rainfall, which was ihe first principal component of the rainfall index series, increased by one unit, the probability would decrease by 27%. If the elevation increased by 10 meters, the probability would decrease by 2%. However, he relationship between Normalized Difference Vegetable Index (NDVI) and the probability of incidence of malaria was different. If the NDVI had a one unit increase, the probability would increase 3.28 times. CONCLUSION: The northern districts of Huai River during 2004-2006 appeared to be a new spatio-temporal cluster when reemergence of malaria epidemics had occurred in Auhui province since 2000. Terrain and physiognomy, nature and circumstances factors, such as temperature and rainfall had affected the incidence rates of malaria. Our research data from Anhui province would provide some important references to the discovery of main reasons on the reemergence of malaria epidemics since 2000, especially in the central geographic areas of China.


Assuntos
Surtos de Doenças , Meio Ambiente , Monitoramento Ambiental/estatística & dados numéricos , Malária/epidemiologia , Malária/prevenção & controle , Animais , China/epidemiologia , Monitoramento Epidemiológico , Humanos , Incidência , Modelos Logísticos
20.
Zhonghua Liu Xing Bing Xue Za Zhi ; 28(8): 802-5, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-18080571

RESUMO

OBJECTIVE: Application of Knox method was discussed in exploring temporal-spatial cluster for infectious diseases. METHODS: The theory of Knox method was introduced in detail. As an example, the temporal-spatial cluster of epidemic cerebrospinal meningitis cases from April to May in 2005 was explored in Beijing and the statistical process of Knox method was clearly demonstrated with related results well interpreted. RESULTS: Only when time and distance threshold values were set as 13 days and 29.67 km, potential temporal-spatial cluster could be detected in epidemic cerebrospinal meningitis cases. CONCLUSION: According to the characteristics of the epidemics, under Knox method, if appropriate threshold values of time and distance were chosen, information on temporal-spatial cluster of infectious diseases could be obtained. According to the records of different time and distance threshold values, the nature of an infectious disease might be explored. Thus Knox method could help us to strengthen the early warning system on infectious disease control strategy.


Assuntos
Doenças Transmissíveis/epidemiologia , Surtos de Doenças , Meningite/epidemiologia , China/epidemiologia , Análise por Conglomerados , Humanos , Fatores de Tempo
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