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991.
Three conventional regression models were compared using the time-series data of the occurrence of haemorrhagic fever with renal syndrome (HFRS) and several key climatic and occupational variables collected in low-lying land, Anhui Province, China. Model I was a linear time series with normally distributed residuals; model II was a generalized linear model with Poisson-distributed residuals and a log link; and model III was a generalized additive model with the same distributional features as model II. Model I was fitted using least squares whereas models II and III were fitted using maximum likelihood. The results show that the correlations between the HFRS incidence and the independent variables measured (i.e. difference in water level, autumn crop production and density of Apodemus agrarius) ranged from -0.40 to 0.89. The HFRS incidence was positively associated with density of A. agrarius and crop production, but was inversely associated with difference in water level. The residual analyses and the examination of the accuracy of the models indicate that model III may be the most suitable in the assessment of the relationship between the incidence of HFRS and the independent variables. 相似文献
992.
通过对9、10月份间杭州高校的无偿献血情况的分析,并以街头流动点的献血者作为对照,笔者发现高校大学生普遍对无偿献血有着积极态度,踊跃参加无偿献血.在这两个月间,此两类采血点共有14892例无偿献血者,其中高校学生5120例,占34.4%,是献血队伍中不可低估的力量.针对高校学生心理承受能力较差的特点,尤其是新生和初次献血者,心理疏导是重要的环节,采取防范措施,减轻献血后的不适反应,防止严重反应,确保在校大学生的安全,是有积极意义的. 相似文献
993.
Gas wave ejectors (GWEs) utilize pressure waves to efficiently transfer energy between gases, and they have broad applications in the chemical industry. In order to improve the performance of GWEs, the influence of bending angles on GWE performance was studied and experiments involving a GWE equipped with curved channels were carried out for the first time in this study. The research results show that when the exhaust angle difference (φdout) is ≤−3.9° and the incident angle difference (φdin) is >5.0° or ≤−5.0°, the equipment performance decreases with an increase in the absolute values of the angle differences. The maximum efficiency of the backward-curved-channel device is 61.6% within the experimental range. The experimental efficiency of the curved-channel device and the static-pressure proportion of the total pressure of the medium-pressure gas are enhanced in comparison with a traditional straight-channel device, and the operating power consumption is relatively reduced. Due to the difference between the gas incident and exhaust angles, the manner in which the performance of the curved-channel device varies with the rotation speed is different depending on the working conditions.The effects of curved rotor channel for enhancing the efficiency of gas wave ejector, improving the portion of static pressure of medium-pressure gas, and reducing operating power consumption are studied by simulation and experiment. 相似文献
994.
Circular RNA (circRNA) participates in a variety of pathophysiological processes, including the development of gastric cancer (GC). However, the role of circ_0006089 in GC progression and its underlying molecular mechanism need to be further revealed. Quantitative real‐time PCR was utilized for detecting circ_0006089, microRNA (miR)‐361‐3p and transforming growth factor‐β1 (TGFB1) expression. The interaction between miR‐361‐3p and circ_0006089 or TGFB1 was confirmed using a dual‐luciferase reporter assay and an RNA immunoprecipitation (RIP) assay. Cell proliferation, metastasis, apoptosis, and angiogenesis were determined using colony formation assay, EdU assay, transwell assay, flow cytometry, and tube formation assay. Cell glycolysis was evaluated by detecting glucose consumption, lactate production, and ATP levels. In addition, western blot (WB) analysis was used to measure protein expression. Xenograft tumor models were used to assess the effect of circ_0006089 knockdown on GC tumorigenesis. circ_0006089 had been found to be upregulated in GC tissues and cells, and it could act as an miR‐361‐3p sponge. circ_0006089 knockdown suppressed GC proliferation, metastasis, glycolysis, angiogenesis, and increased apoptosis, while this effect could be revoked by miR‐361‐3p inhibitor. TGFB1 was targeted by miR‐361‐3p, and its overexpression reversed the effects of miR‐361‐3p on GC cell function. Also, circ_0006089 promoted TGFB1 expression via sponging miR‐361‐3p. Animal experiments showed that silenced circ_0006089 inhibited GC tumorigenesis through the miR‐361‐3p/TGFB1 pathway. Our results revealed that the circ_0006089/miR‐361‐3p/TGFB1 axis contributed to GC progression, confirming that circ_0006089 might be a potential therapeutic target for GC. 相似文献
995.
目的了解抗菌药物对革兰阴性杆菌AmpC酶从诱导耐药型向持续高产型转变的影响作用。方法筛选携带诱导型菌株的患者作为研究对象,定期收集其感染标本,至转化为持续高产型,并对其菌种、基础疾病、期间抗菌药物使用种类及用量进行统计分析。结果 152株诱导型菌株中,68株转化为持续高产型,其中12株阴沟肠杆菌全部转化,转化率达100.0%;脑梗死患者的细菌更易转化(83.3%,OR=7.1);头孢菌素类(95.3%/64.6%)、多肽类(18.95%/15.5%)、青霉素类+β-内酰胺酶抑制剂(128.8%/276.0%)以及碳青酶烯类+β-内酰胺类(58.9%/82.3%)抗菌药物的用量对持续高产型AmpC酶的产生有着显著的影响(P0.05),其中后两者剂量与转化率呈正相关,前两者呈负相关。结论大剂量青霉素类+β-内酰胺酶抑制剂和碳青酶烯类+β-内酰胺类抗菌药物可能会促进诱导型产酶菌株转变为持续高产型产酶菌株。 相似文献
996.
Season modifies the relationship between bone and blood lead levels: the Normative Aging Study 总被引:1,自引:0,他引:1
Bone serves as a repository for 75% and 90-95% of lead in children and adults, respectively. Bone lead mobilization heightens during times of increased bone turnover, such as pregnancy, lactation, hyperthyroidism, and the rapid growth of childhood. Blood lead levels show seasonal periodicity. Children demonstrate peak blood lead levels in mid-summer and a secondary peak in late winter. Pregnant women demonstrate the highest mean blood lead levels in winter (January-March) and the lowest in summer (July-September). This fluctuation in blood lead levels may be related to seasonal patterns of environmental exposures, but it may also be partially related to the increased mobilization of bone lead stores during the winter months. We performed bone lead measurements using a K-x-ray fluorescent instrument to determine micrograms of lead per gram of bone mineral (parts per million) in middle-aged and elderly men who participated in the Normative Aging Study. We obtained measurements of blood and bone lead during the high sun exposure months of May-August (summer; n = 290); the intermediate sun exposure months of March, April, September, and October (spring/fall; n = 283); and the low sun exposure months of November-February (winter; n = 191). Mean blood lead concentrations were 5.8 microg/dl, 6.1 microg/dl, and 6.6 microg/dl for the summer, spring/fall, and winter, respectively. Mean patella (trabecular bone) lead concentrations were 34.3 microg/gm, 29.7 microg/gm, and 29.0 microg/gm for the summer, spring/fall, and winter time periods, respectively. In multivariate regression models, adjusted for age, smoking, alcohol ingestion, and dietary intake of iron and vitamin C, the authors found a strong interaction between season and bone lead level--with bone lead levels exerting an almost 2-fold greater influence on blood levels during the winter months than the summer months. The authors concluded that elevated blood lead levels in winter may be related to increased mobilization of endogenous bone lead stores, potentially from decreased exposure to sunlight, lower levels of activated vitamin D, and enhanced bone resorption. 相似文献
997.
Dongli Xie Jianchen Hu Zhenhua Yang Tong Wu Wei Xu Qingyang Meng Kangli Cao Xiaogang Luo 《Nutrients》2022,14(11)
The extensive applications of nanomaterials have increased their toxicities to human health. As a commonly recommended health care product, vitamins have been reported to exert protective roles against nanomaterial-induced oxidative stress and inflammatory responses. However, there have been some controversial conclusions in regards to this field of research. This meta-analysis aimed to comprehensively evaluate the roles and mechanisms of vitamins for cells and animals exposed to nanomaterials. Nineteen studies (seven in vitro, eleven in vivo and one in both) were enrolled by searching PubMed, EMBASE, and Cochrane Library databases. STATA 15.0 software analysis showed vitamin E treatment could significantly decrease the levels of oxidants [reactive oxygen species (ROS), total oxidant status (TOS), malondialdehyde (MDA)], increase anti-oxidant glutathione peroxidase (GPx), suppress inflammatory mediators (tumor necrosis factor-α, interleukin-6, C-reactive protein, IgE), improve cytotoxicity (manifested by an increase in cell viability and a decrease in pro-apoptotic caspase-3 activity), and genotoxicity (represented by a reduction in the tail length). These results were less changed after subgroup analyses. Pooled analysis of in vitro studies indicated vitamin C increased cell viability and decreased ROS levels, but its anti-oxidant potential was not observed in the meta-analysis of in vivo studies. Vitamin A could decrease MDA, TOS and increase GPx, but its effects on these indicators were weaker than vitamin E. Also, the combination of vitamin A with vitamin E did not provide greater anti-oxidant effects than vitamin E alone. In summary, we suggest vitamin E alone supplementation may be a cost-effective option to prevent nanomaterial-induced injuries. 相似文献
998.
999.
本文提出了综合评价医院工作的一种方法——指标加权百分位次累加法。本方法分五个步骤:1.建立评价指标体系;2.制定评价标准值;3.对指标值进行标准化;4.根据指标重要程度赋予相应权重;5.进行综合评价。并通过实际资料对本方法进行了验证。 相似文献
1000.
目的通过对青藏铁路建设以来青海省境内沿线鼠疫监测资料的总结分析,科学评估这一地区鼠疫流行动态,探讨青藏铁路沿线鼠疫防治思路。方法监测点按照《青藏铁路鼠疫防治技术方案》和《青藏铁路鼠疫防控工作方案》实施监测工作,铁路沿线的国家级监测点按照《全国鼠疫监测方案》实施监测工作。汇总分析2001-2008年青藏铁路沿线青海省境内的鼠疫监测资料。结果2001-2008年监测面积达224190km^2,收集可检啮齿动物材料5822份、媒介材料2617份、动物血清4966份。分离到鼠疫菌93株,监测到阳性血清249份。结论近年来青藏铁路沿线动物间鼠疫流行活跃且呈上升趋势。青藏铁路沿线的乌兰县、天峻县是鼠疫流行较为严重的地区。怎样预防鼠疫沿青藏铁路线远距离传播,应引起相关部门的高度重视。 相似文献