Monthly district level risk of dengue occurrences in Sakon Nakhon Province, Thailand

The paper deals with the incidence of the Dengue Virus Infection (DVI) in the 18 districts of Sakon Nakhon Province, Thailand, from January 2005 to December 2007. Using a statistical and autoregressive analysis to smooth incidence data, we have constructed yearly and monthly district level maps of the DVI distribution. It is found that the DVI incidence is very correlated with weather conditions and higher occurrences are observed in the three most populated districts Wanon Niwat, Sawang Daen Din and Mueang Sakon Nakhon, and the virus transmission period spans from mid-summer to mid-rainy seasons (from April to August). Employing a Generalized Linear Model (GLM), we found that the DVI incidences were related with current meteorological (monthly minimum temperature, past 2-month cumulated rainfall) and socio-economical (population of 0-4 years old, per capita number of public small water wells, and proportion of villages with primary schools) covariates. And using the GLM under the climate change conditions (A1B scenario of IPCC), we found that the higher risk of DVI spreads from the three most populated districts to less populated ones, and the period of virus transmission increases from 5 to 9 months to include part of winter, summer and rainy seasons (from March to November) during which 6%, 61% and 33% of districts will be at low, medium and high risk of DVI occurrences, respectively.     

The feasibility of MS and advanced data processing for monitoring Schistosoma mansoni infection

Purpose : Sensitive diagnosis, monitoring of disease progression and the evaluation of chemotherapeutic interventions are of prime importance for the improvement of control and prevention strategies for Schistosomiasis. The aim of the present study was to identify novel markers of Schistosoma mansoni infection and disease using urine samples from a large cohort from an area endemic for S. mansoni. Experimental design : Urine samples were collected and processed on an automated sample clean‐up and fractionation system combining strong cation exchange and reversed phase, and analyzed by MS (MALDI ToF MS). The ClinPro Tools^? (CPT) software and the Discrete Wavelet Transformation–Support Vector Machine (DWT‐SVM) procedure were used for classification and statistical analysis. Results : We observed a large difference in urinary peptide profiles between children and adults but classification based on infection was possible only for children. Here, in the external validation data set, 93% of the infected children were classified correctly with DWT‐SVM (versus 76% for CPT). In addition 91% of low‐infected children were classified correctly using DWT‐SVM (versus 85% for CPT). The discriminating peptides were identified as fragments of collagen 1A1 and 1A3, and uromodulin. Conclusions and clinical relevance : In conclusion, we provide the usefulness of a peptidomics profiling approach combined with DWT‐SVM in the monitoring of S. mansoni infection.     

多城市SARS疫情的仿真研究

该文通过仿真手段讨论多个城市之间SARS疫情演化问题。首先提出仿真的限定条件，然后利用面向对象技术分析了SARS疫情仿真所涉及的对象类，阐述了仿真工作线程的运行流程，最后给出了仿真运行的结果。仿真运行结果表明必须在采取防疫措施的同时采取隔离措施才能有效地阻止SARS传播，使疫情很快得到控制。     

Proteomics of hosts and pathogens in cystic fibrosis

Cystic fibrosis (CF) is a congenital disease that results in great morbidity and mortality mainly in the Caucasian population. Although CF is a monogenic disease caused by mutation in the CF conductance transmembrane regulator (CFTR) gene, most of the related mortality can be attributed to infection mediated by opportunistic bacterial and fungal pathogens. Over the past decade, advancements in the field of proteomics have helped to gain insight into the repertoire of host and pathogen proteins involved in CF pathophysiology. This review provides an overview of the contributions of proteomic studies in advancing our knowledge of the biology of CF and disease progression associated with pathogen infection and host defense responses.     

浅谈计算机系统安全

随着计算机在日常生活中的普及,人们对计算机的依赖越来越强,计算机系统安全、数据安全成了一个必须引起高度重视的问题。通过备份数据、安装系统补丁、安装杀毒软件可以有效地保障计算机系统安全和数据安全。     

Multi-zone modeling of probable SARS virus transmission by airflow between flats in Block E, Amoy Gardens

More than 300 residents of a private high-rise housing estate were infected with severe acute respiratory syndrome within a short period during the 2003 epidemic in Hong Kong. The outbreak occurred after the identified index patient visited a flat on a middle floor in Block E of the Amoy Gardens estate on two nights. Approximately 45% of the subsequently infected people resided in Block E, while the other 55% of infected cases mainly resided in six other blocks close to Block E. The distribution of the infected flats in Block E conformed to a non-uniform spatial pattern. Probable environmental causes for airborne transmission associated with the air movements between flats in Block E are identified. The well-established multi-zone airflow modeling method was used to analyze the virus-laden bio-aerosol dispersion between flats through door and window leakage areas in Block E under six different scenarios. The distribution of infection risk in Block E matched with the virus concentrations in flats predicted with the use of multi-zone modeling. Our study shows the importance of ventilation design in high-rise residential apartments. PRACTICAL IMPLICATIONS: The present study on the Amoy Gardens outbreak presented a scenario in which crowded living spaces might lead to infection disasters. There is a need to improve the current sanitary drainage design and maintenance standards to avoid any leakage of foul gas into the indoor environments. Our study revealed the need for a review of indoor air quality and ventilation design in buildings including offices, homes and hotels. The study has implications to public health in, for example, the control of other airborne respiratory infectious diseases such as influenza, and in bio-terror safety in buildings.     

Dispersion of exhaled droplet nuclei in a two-bed hospital ward with three different ventilation systems

Effective ventilation in general hospital wards is important for controlling the airborne transmission of infectious respiratory diseases. Experiments have been carried out to increase our understanding of the interaction of the breathing flows of two individuals in a full-scale experimental hospital ward with three ventilation systems, i.e. mixing, downward and displacement ventilation. Two life-size breathing thermal manikins were used to simulate a source patient and a receiving patient. The exhalation jet from a bed-lying manikin was visualized using smoke. N2O was used as tracer gas to simulate the droplet nuclei exhaled by patients; and the spatial distribution of its concentrations was measured. Our experimental results show that for both mixing and downward ventilation, the exhaled jet penetrates a short distance and is diluted quickly by ventilation air. The exhaled droplet nuclei are well mixed in the ward. Bed distance does not affect the personal exposure of the receiving patient. For displacement ventilation, the exhaled jet can penetrate a long distance. A high concentration layer of exhaled droplet nuclei because of thermal stratification locking has also been observed with displacement ventilation. This work is useful for identifying an appropriate ventilation method that can remove droplet nuclei more effectively and minimize the risk of cross-infections in a hospital ward environment. PRACTICAL IMPLICATIONS: As one of the major potential sources for infectious droplet nuclei in a hospital environment, exhalation flows of an infected patient can interact with the respiratory activities of other close individuals and with the room ventilation systems. Our latest results provide information on the penetration of exhalation jets into the ambient environment in different ventilation systems. This work is useful in identifying an appropriate and effective ventilation method for removing droplet nuclei more effectively, and thus minimizing the risk of cross-infections in hospital wards with multiple beds.     

Dispersion of exhalation pollutants in a two-bed hospital ward with a downward ventilation system

The Centers for Disease Control and Prevention has recommended the use of downward ventilation systems in isolation rooms to reduce the risk of cross-infection from airborne transmissible diseases. The expected airflow pattern of a downward ventilation design would supply cooler and slightly heavier clean air from a ceiling diffuser to push down contaminants, which would then be removed via outlets at floor level. A “laminar” (strictly speaking, unidirectional) flow is expected to be produced to avoid flow mixing and thus reduce cross-infection risk. Experiments were carried out in a full-scale experimental hospital ward with a downward ventilation system to investigate the possibility of applying downward ventilation in a general hospital ward. Two life-sized breathing thermal manikins were used to simulate a source patient and a receiving patient. Computation fluid dynamics was also used to investigate the airflow pattern and pollutant dispersion in the test ward. Based on both experimental and numerical results, the laminar airflow pattern was shown to be impossible to achieve due to turbulent flow mixing and flow entrainment into the supply air stream. The thermal plumes produced above people were found to induce flow mixing. We also studied the effects of the locations of the supply and extraction openings on both the flow pattern and pollutant exposure level in the occupied zone. A number of practical recommendations are suggested.     

基于PLC的医疗室利用机器人分析

在医学生物实验室开展高致病性病原微生物的研究中实验人员常常会与病原微生物的直接接触，会造成他们一定职业感染的危险性，如何确保生物安全实验室的安全性是非常重要的。本文将介绍一个在一个几何平面内自由移动的基于PLC的四轴机器人，可以取代医疗室实验人员，并且能够高速取放、抓取、旋转和其他材料处理任务的作用。通过周密的研制的设计方案，以实现机器人应用医疗室，并为人类服务的目的。