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81.
目的 分析抚顺地区泌尿生殖道解脲支原体和人型支原体感染情况及药敏情况。方法 采用支原体培养、鉴定、药敏一体化试剂盒对710名患者进行解脲支原体(Uu)和人型支原体(Mh)检测和其对9种抗菌药物的药敏试验。结果 710名患者中共检出支原体感染者200名,阳性率为28.17%。其中Uu 140名(19.71%),Mh 12名(1.69%),Uu+Mh混合感染48名(6.76%)。药敏结果表明,支原体对强力霉素、美满霉素和克拉霉素敏感率高,分别为95.71%,98.57%和91.42%。结论 抚顺地区支原体感染发病率较高,以单纯Uu感染为主,美满霉素是治疗支原体感染的首选药物。  相似文献   
82.
池州森林生态系统服务价值评估与分析   总被引:2,自引:0,他引:2  
池州市是国家首个生态经济示范区,《中国21世纪议程》试点地之一,生态安徽建设试点市.基于LY/T1721-2008《森林生态系统生态服务价值评估规范》,采用实证研究、调查研究、文献研究等方法,估算了池州市森林生态系统生态服务价值.结果表明:2009年,池州市森林生态系统生态服务价值为443.30亿元,林果等实物产品价值...  相似文献   
83.
外来木本植物入侵的生态预测与风险评价综述   总被引:3,自引:0,他引:3  
郑景明  李俊清  孙启祥  周金星 《生态学报》2008,28(11):5549-5560
外来植物引种导致的入侵已经成为当前生物多样性保育和引种工作面临的一个紧要研究课题。综述了木本植物入侵的生态预测和生态风险评价方面的国内外相关研究进展。首先介绍了目前国内外木本植物引种的概况,对木本植物入侵的生态预测基本原理做了较为详细的总结。目前比较被认可的生态预测途径主要包括编辑入侵植物名录利用入侵历史纪录预测、物种特征作为入侵的预测指标、繁殖体压力作为建群概率的决定性因素、环境匹配作为入侵潜力的预测工具及专家意见等,并对物种特征进行了归类和分析。物种特征指标主要包括物种的繁殖和快速生长性状指标、对入侵地区局部条件和干扰体系的适应性指标、生物地理分布指标等,并指出在生态预测中单独使用这些指标是不严谨的,而应当多途径互相结合验证。同时还简介了WRA等几个应用较为广泛的实用性植物入侵风险评价系统。分析了目前国内外在木本植物入侵的生态预测方面面临的一些困难,包括入侵机理的复杂性导致的预测难度增大和可信性下降,所用数据库标准的不统一和更新的困难等,指出在进行木本植物引种的生态预测和风险评价研究的同时,必须加强相关法律法规建设,重视入侵机理研究,完善相关的数据库。出于实际情况的限制,可以借鉴国际上实用性杂草风险分析和有害生物风险分析的方法,逐步建立我国的入侵风险评价系统,以满足目前对木本植物入侵的预测和风险评价的需求。  相似文献   
84.
杨莉  刘宁  戴明忠  陆根法 《生态学报》2008,28(11):5610-5618
消费问题是区域生态环境压力增大和生态环境问题产生的根本原因。提出人口环境消费的概念和理论模型,并在生态足迹理论和方法的支撑下分别计算江苏省江阴市1997~2004年城镇居民和农村居民生活消费的环境压力;采用SPSS14.0软件,分析城镇和农村居民这两类人群人均环境消费的变化规律及其影响因素,并通过建立多元线性回归预测模型,估算在城镇化快速发展的情况下江阴市人口环境消费期望值。研究表明:江阴市城镇居民人均环境消费从1997年的1.395hm^2上升到2004年的1.960hm^2,年均递增0.081hm^2;农村居民则从1997年的1.345hm^2上升到2004年的1.465hm^2,年均递增0.017hm^2。城乡居民人均环境消费与人均可支配收入、人均受教育年限、恩格尔系数、人均地区生产总值等社会经济指标呈显著线性相关。预计到2010年城乡居民人均环境消费将分别达到2.258hm^2和1.919hm^2,到2020年将分别达到2.807hm^2和2.303hm2;2010年和2020年区域生态赤字将比2004年分别增长55%和107%,给区域生态环境造成巨大压力。为有效缓解区域环境压力,论文提出合理控制区域人口规模和城镇化发展速度,大力发展生态产业,培养可持续消费观念,引导绿色、健康和环境友好型的消费模式等对策措施。  相似文献   
85.
Polycyclic aromatic hydrocarbons (PAHs) are a large class of organic chemicals typically found as mixtures in the aquatic environment from natural, petrogenic, and pyrogenic sources. People can be exposed to PAHs through ingestion or dermal contact with contaminated sediments or through ingestion of finfish and shellfish exposed to contaminated sediments. Although more than 100 PAHs have been identified, human exposure and risk are commonly evaluated for 18 individual PAHs. Other PAHs, such as alkylated PAHs, likely contribute to biological activity of environmental PAH mixtures; however, insufficient toxicity data are available to quantify their potential risk. This article presents an initial evaluation of the potential for human health risk from exposure to alkylated PAHs in sediment and fish. Individual alkylated PAHs have been observed to have potentially mutagenic, tumor-promoting, or carcinogenic activity. However, except for 1-and 2-methylnaphthalene, insufficient toxicity data are available to quantify toxicity or cancer risk from exposure to individual alkylated PAHs or mixtures of alkylated PAHs. This article describes a proposed strategy to better understand the potential human health risk from exposure to alkylated PAHs. Implementation of this strategy will contribute to evaluations of human exposure to complex PAH mixtures in the environment.  相似文献   
86.
目的:应用改良CCI模型研究外周神经损伤后痛觉过敏和自发放电各自特征及相互关系。方法:雄性SD大鼠,随机分为CCI组和Sham组,分别于术前1天和术后1、4、7、9、11、14天测定机械刺激缩足反射阈值和热缩腿反射潜伏期,同时选取术侧机械刺激缩腿反射阈值低于4g或者术侧和健侧热缩腿反射潜伏期差异大于2s的CCI模型大鼠观察术后4-14天损伤区自发放电活动。结果:神经纤维损伤后,机械痛敏和热痛敏随时间表现为逐渐增强,同时在损伤区观察到三类放电模式:整数倍放电﹑阵发放电和周期放电。结论:术后大鼠机械痛阈和热痛阈逐渐降低,机械痛敏的产生和损伤区自发放电活动关系密切,不同的放电模式可能代表不同的传入信息。  相似文献   
87.
Identifying which introduced species have the greatest potential for establishment, spread and impact is critical for prioritizing pre‐ and post‐border control. Using species distribution modelling and existing species locations we assessed the establishment risk based on the climatic suitability areas of 25 plant species listed as eradication targets under South African regulations. To improve confidence, three bioclimatic models were used to predict the potential distribution of each species. This information was combined with the number of localities and the “eradication feasibility syndromes” in a scoring‐categorical system to rank the species. Three management groups were identified. Group “A” includes species with medium‐high establishment risk and higher likelihood to be eradicated, these species should be a priority for eradication. Group “B” includes species with a medium‐low establishment risk but given the low number of known population and the species characteristics, eradication is likely to be feasible. Finally species in group “C” scored a medium‐high establishment risk but the eradication would be difficult due to the high number of known localities. This ranking provides a rapid method to prioritize the management towards the eradication of new potential invasive plant species in the country combining the establishment risk, known number of localities and the inferred eradication success.  相似文献   
88.
As a consequence of both increasing population and industrialization in agro-economic sector, Pakistan has inevitably been confronted by multicomplex environmental challenges. Owing in part to poor regulatory framework, pollution due to persistent organic pollutants (POPs) has caused serious problems throughout the country. Resultantly, extensive use of POPs is causing vigorous deterioration of environment and human health. The current study addresses: (1) the general information on associated ecological effects and toxicity assessment by meta-analysis for local fauna and flora (2) their respective occurrence in living organisms; and (3) sources and distribution patterns of various POPs classes in environmental compartments of Pakistan. Based on the study, it can be concluded that the environment of Pakistan is highly contaminated with organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), and polychlorinated naphthalenes (PCNs), which is further supported with the meta-analysis. Nevertheless, unavailability of environmental quality standards and food safety for POPs render it a forthcoming challenge of multicompartment toxicity exposure. Therefore, strategies must be planned for risk assessment of biologically active POPs, while the POP waste inventory should be elevated, along with the necessary measures to promote appropriate handling and treatment of POP as a matter of prime importance.  相似文献   
89.
We demonstrate the use of the near‐infrared attenuation coefficient, measured using optical coherence tomography (OCT), in longitudinal assessment of hypertrophic burn scars undergoing fractional laser treatment. The measurement method incorporates blood vessel detection by speckle decorrelation and masking, and a robust regression estimator to produce 2D en face parametric images of the attenuation coefficient of the dermis. Through reliable co‐location of the field of view across pre‐ and post‐treatment imaging sessions, the study was able to quantify changes in the attenuation coefficient of the dermis over a period of ~20 weeks in seven patients. Minimal variation was observed in the mean attenuation coefficient of normal skin and control (untreated) mature scars, as expected. However, a significant decrease (13 ± 5%, mean ± standard deviation) was observed in the treated mature scars, resulting in a greater distinction from normal skin in response to localized damage from the laser treatment. By contrast, we observed an increase in the mean attenuation coefficient of treated (31 ± 27%) and control (27 ± 20%) immature scars, with numerical values incrementally approaching normal skin as the healing progressed. This pilot study supports conducting a more extensive investigation of OCT attenuation imaging for quantitative longitudinal monitoring of scars.

En face 2D OCT attenuation coefficient map of a treated immature scar derived from the pre‐treatment (top) and the post‐treatment (bottom) scans. (Vasculature (black) is masked out.) The scale bars are 0.5 mm.  相似文献   

90.
Bhasin M  Zhang H  Reinherz EL  Reche PA 《FEBS letters》2005,579(20):4302-4308
DNA methylation plays a key role in the regulation of gene expression. The most common type of DNA modification consists of the methylation of cytosine in the CpG dinucleotide. At the present time, there is no method available for the prediction of DNA methylation sites. Therefore, in this study we have developed a support vector machine (SVM)-based method for the prediction of cytosine methylation in CpG dinucleotides. Initially a SVM module was developed from human data for the prediction of human-specific methylation sites. This module achieved a MCC and AUC of 0.501 and 0.814, respectively, when evaluated using a 5-fold cross-validation. The performance of this SVM-based module was better than the classifiers built using alternative machine learning and statistical algorithms including artificial neural networks, Bayesian statistics, and decision trees. Additional SVM modules were also developed based on mammalian- and vertebrate-specific methylation patterns. The SVM module based on human methylation patterns was used for genome-wide analysis of methylation sites. This analysis demonstrated that the percentage of methylated CpGs is higher in UTRs as compared to exonic and intronic regions of human genes. This method is available on line for public use under the name of Methylator at http://bio.dfci.harvard.edu/Methylator/.  相似文献   
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