529 research outputs found

    The Application of Intracardiac Ultrasound in Atrial Septal Puncture

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    Objectives: To investigate the safety and effectiveness of atrial septal puncture assisted by intracardiac ultrasound, and to evaluate the value of intracardiac ultrasound in atrial septal puncture. Methods: Sixty patients who underwent radiofrequency ablation for the first time were randomly divided into two groups. Patients in experimental group underwent intraventricular ultrasound-assisted atrial septal puncture, while those in control group underwent X-ray guided atrial septal puncture. The success rate, puncture time and complications of the two groups were compared. Results: All atrial septal puncture was successful in the experimental group, while one-time puncture was successful in 21 cases and unsuccessful in 9 cases in the control group with a success rate of 83.33%. There was significant difference in puncture success rate between the two groups. Moreover, the puncture time of the experimental group (5.00±1.5 min) was significantly shorter than that of the control group (6.90±1.32 min). Furthermore, the complication rates of the experimental group and the control group were 10% and 13.33%, respectively, with no significant difference. Conclusion: Ultrasound-assisted atrial septal puncture was significantly superior to X-ray guided atrial septal puncture, with high puncture success rate, short puncture time and fewer complications

    Seroprevalence of Bartonella in Eastern China and analysis of risk factors

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    <p>Abstract</p> <p>Background</p> <p><it>Bartonella </it>infections are emerging in the Zhejiang Province of China. However, there has been no effort to date to explore the epidemiology of these infections in this region, nor to identify risk factors associated with exposure to <it>Bartonella</it>. The aim of this study was to investigate the seroprevalence of <it>Bartonella </it>in both patients bitten by dogs and blood donors (for control) in Eastern China, and to identify risk factors associated with exposure to <it>Bartonella</it>. As no previous data for this region have been published, this study will provide baseline data useful for <it>Bartonella </it>infection surveillance, control, and prevention.</p> <p>Methods</p> <p>Blood samples were collected from industrial rabies clinic attendees and blood donors living in eight areas of the Zhejiang Province of China, between December 2005 and November 2006. An indirect immunofluorescent antibody test was used to determine the presence of <it>Bartonella </it>in these samples. Risk factors associated with <it>Bartonella </it>exposure were explored using Chi-square tests and logistic regression analysis of epidemiological data relating to the study's participants.</p> <p>Results</p> <p><it>Bartonella </it>antibodies were detected in 19.60% (109/556) of blood samples. Seroprevalence varied among the eight areas surveys, ranging from over 32% in Hangzhou to only 2% in Jiangshan (X<sup>2 </sup>= 28.22, P < 0.001). We detected a significantly higher prevalence of <it>Bartonella </it>antibodies in people who had been bitten by dogs than in blood donors (X<sup>2 </sup>= 13.86, P < 0.001). Seroprevalence of <it>Bartonella </it>was similar among males (18.61%, n = 317) and females (20.92%, n = 239).</p> <p>Conclusions</p> <p><it>Bartonella </it>antibodies were encountered in people living across Zhejiang Province and the seropositivity rate among those exposed to dog bites was significantly higher than that among blood donors, indicating that dog bites may be a risk factor for <it>Bartonella </it>infection.</p

    Flow field and noise characteristics of manifold in natural gas transportation station

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    International audienceManifolds play a role of pressure balance, buffering and rectification for different branch pipelines, the flow noise of manifolds has been a serious problem all this time in natural gas transmission station. By changing the number of outlet pipes of manifolds and the different positions of intake pipes, the distribution of the Sound Pressure Level (SPL) of the manifold flow noise is analyzed based on the Ffowcs Williams-Hawkings (FW-H) acoustic analogy theory and Large Eddy Simulations (LESs). The three-dimensional simulation analysis of the flow field shows that pressure pulsation is the mainly source of manifold noise, as the number of outlet pipe increases, the SPLs of fluid dynamic noise at the end of inlet pipes are significantly reduced by about 10 dB on average, when the inlet and outlet piping are oppositely connected, the SPL is 2 dB~3 dB lower than that in staggered connections. An expansion-chamber muffler is designed with the analysis of its noise reduction effect, the results show that after the muffler is installed, the noise reduction in the low-frequency ranges reaches up to 37.5 dB, which controls the maximum noise to around 82 dB

    Coexistence of Aedes aegypti and Aedes albopictus in Jinghong City, Yunnan Province: A Survey of Aedes aegypti Invasion

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    We conducted this study to confirm that Aedes aegypti has invaded and colonized in Xishuangbanna, Yunan province, China. And we conducted a larval survey for dengue mosquito vectors, Ae. aegypti and Ae. albopictus, to assess on possible competition for breeding sites between these both species in urban environment in Jinghong city. The study was carried out at least once a month in February and March, November and December, and three times for each month from April to October in 2014 in five communities in the municipality of Jinghong city. No less than 50 houses were surveyed each time in one place. We collected immature stages of mosquitoes from all types of breeding sites in houses and their premises. Morphological species identification was carried for Ae. aegypti and Ae. albopictus. Both species occurred in all surveyed areas. Aedes aegypti has occupied a considerable composition (67.75%) since the uncertain time of its first invasion to Jinghong city. Aedes aegypti was predominant species indoor (74.19%), but also presented in surrounding environment (25.81%); while Ae. albopictus favored the outdoor environment (54.55%) as well as in houses (45.45%). We gave the preference water containers (tires) for dengue vectors, described different distribution in different investigated places, and showed with monthly variance by indices of BI and CI. We gave our rational explanation for the variance with raining in this area, Aedes keep a high density value during the rainy season. For both dengue vectors, the possibility cannot be excluded that the invasion of Ae. aegypti in the city might lead to a decrease or elimination of Ae. albopictus in houses and dwellings. Furthermore, we also found that both dengue vectors have already occupied the breeding sites in houses and their premises with water container in Jinghong city, and both should be managed during dengue epidemic season. These findings from this study are relevant for dengue vector control programs

    Climate Change Drives the Transmission and Spread of Vector-Borne Diseases: An Ecological Perspective

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    Climate change affects ecosystems and human health in multiple dimensions. With the acceleration of climate change, climate-sensitive vector-borne diseases (VBDs) pose an increasing threat to public health. This paper summaries 10 publications on the impacts of climate change on ecosystems and human health; then it synthesizes the other existing literature to more broadly explain how climate change drives the transmission and spread of VBDs through an ecological perspective. We highlight the multi-dimensional nature of climate change, its interaction with other factors, and the impact of the COVID-19 pandemic on transmission and spread of VBDs, specifically including: (1) the generally nonlinear relationship of local climate (temperature, precipitation and wind) and VBD transmission, with temperature especially exhibiting an n-shape relation; (2) the time-lagged effect of regional climate phenomena (the El Niño–Southern Oscillation and North Atlantic Oscillation) on VBD transmission; (3) the u-shaped effect of extreme climate (heat waves, cold waves, floods, and droughts) on VBD spread; (4) how interactions between non-climatic (land use and human mobility) and climatic factors increase VBD transmission and spread; and (5) that the impact of the COVID-19 pandemic on climate change is debatable, and its impact on VBDs remains uncertain. By exploring the influence of climate change and non-climatic factors on VBD transmission and spread, this paper provides scientific understanding and guidance for their effective prevention and control

    Comparative Evaluation of the LAMP Assay and PCR-Based Assays for the Rapid Detection of Alternaria solani

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    Early blight (EB), caused by the pathogen Alternaria solani, is a major threat to global potato and tomato production. Early and accurate diagnosis of this disease is therefore important. In this study, we conducted a loop-mediated isothermal amplification (LAMP) assay, as well as conventional polymerase chain reaction (PCR), nested PCR, and quantitative real-time PCR (RT-qPCR) assays to determine which of these techniques was less time consuming, more sensitive, and more accurate. We based our assays on sequence-characterized amplified regions of the histidine kinase gene with an accession number (FJ424058). The LAMP assay provided more rapid and accurate results, amplifying the target pathogen in less than 60 min at 63°C, with 10-fold greater sensitivity than conventional PCR. Nested PCR was 100-fold more sensitive than the LAMP assay and 1000-fold more sensitive than conventional PCR. qPCR was the most sensitive among the assays evaluated, being 10-fold more sensitive than nested PCR for the least detectable genomic DNA concentration (100 fg). The LAMP assay was more sensitive than conventional PCR, but less sensitive than nested PCR and qPCR; however, it was simpler and faster than the other assays evaluated. Despite of the sensitivity, LAMP assay provided higher specificity than qPCR. The LAMP assay amplified A. solani artificially, allowing us to detect naturally infect young potato leaves, which produced early symptoms of EB. The LAMP assay also achieved positive amplification using diluted pure A. solani culture instead of genomic DNA. Hence, this technique has greater potential for developing quick and sensitive visual detection methods than do other conventional PCR strategies for detecting A. solani in infected plants and culture, permitting early prediction of disease and reducing the risk of epidemics

    Spatial and temporal distribution of falciparum malaria in China

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    Background: Falciparum malaria is the most deadly among the four main types of human malaria. Although great success has been achieved since the launch of the National Malaria Control Programme in 1955, malaria remains a serious public health problem in China. This paper aimed to analyse the geographic distribution, demographic patterns and time trends of falciparum malaria in China. Methods: The annual numbers of falciparum malaria cases during 1992–2003 and the individual case reports of each clinical falciparum malaria during 2004–2005 were extracted from communicable disease information systems in China Center for Diseases Control and Prevention. The annual number of cases and the annual incidence were mapped by matching them to corresponding province- and county-level administrative units in a geographic information system. The distribution of falciparum malaria by age, gender and origin of infection was analysed. Time-series analysis was conducted to investigate the relationship between the falciparum malaria in the endemic provinces and the imported falciparum malaria in non-endemic provinces. Results: Falciparum malaria was endemic in two provinces of China during 2004–05. Imported malaria was reported in 26 non-endemic provinces. Annual incidence of falciparum malaria was mapped at county level in the two endemic provinces of China: Yunnan and Hainan. The sex ratio (male vs. female) for the number of cases in Yunnan was 1.6 in the children of 0–15 years and it reached 5.7 in the adults over 15 years of age. The number of malaria cases in Yunnan was positively correlated with the imported malaria of concurrent months in the non-endemic provinces. Conclusion: The endemic area of falciparum malaria in China has remained restricted to two provinces, Yunnan and Hainan. Stable transmission occurs in the bordering region of Yunnan and the hilly-forested south of Hainan. The age and gender distribution in the endemic area is characterized by the predominance of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted

    Assessment of the economic impacts of heat waves: A case study of Nanjing, China

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    The southeast region of China is frequently affected by summer heat waves. Nanjing, a metropolitan city in Jiangsu Province, China, experienced an extreme 14-day heat wave in 2013. Extreme heat can not only induce health outcomes in terms of excess mortality and morbidity (hospital admissions) but can also cause productivity losses for self-paced indoor workers and capacity losses for outdoor workers due to occupational safety requirements. All of these effects can be translated into productive working time losses, thus creating a need to investigate the macroeconomic implications of heat waves on production supply chains. Indeed, industrial interdependencies are important for capturing the cascading effects of initial changes in factor inputs in a single sector on the remaining sectors and the economy. To consider these effects, this paper develops an interdisciplinary approach by combining meteorological, epidemiological and economic analyses to investigate the macroeconomic impacts of heat waves on the economy of Nanjing in 2013. By adopting a supply-driven input-output (IO) model, labour is perceived to be a key factor input, and any heat effect on human beings can be viewed as a degradation of productive time and human capital. Using this interdisciplinary tool, our study shows a total economic loss of 27.49 billion Yuan for Nanjing in 2013 due to the heat wave, which is equivalent to 3.43% of the city's gross value of production in 2013. The manufacturing sector sustained 63.1% of the total economic loss at 17.34 billion Yuan. Indeed, based on the ability of the IO model to capture indirect economic loss, our results further suggest that although the productive time losses in the manufacturing and service sectors have lower magnitudes than those in the agricultural and mining sectors, they can entail substantial indirect losses because of industrial interdependencies. This important conclusion highlights the importance of incorporating industrial interdependencies and indirect economic assessments in disaster risk studies
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