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1.
东海区绿鳍马面鲀的早期发育和产卵场、产卵期的探讨   总被引:1,自引:0,他引:1  
1.1972—1982年我们在东海采集到绿鲭马面纯仔、稚鱼3,085尾,仔、稚鱼体长为1.46—9.25毫米。 2.根据人工授精资料,我们鉴定为绿鳍马面纯的仔、稚鱼,并对各发育阶段的形态特征进行了描述。 3.绿鳍马面纯的产卵场、产卵期了解很少。根据调查和观察,产卵期为4月上旬到5月中旬,主要产卵期在4月中、下旬。产卵场在我国钓鱼岛西北部。 4.绿鳍马面鲀产卵与黑潮暖流的高温、高盐水有关。产卵场水温主要为22°—23℃.盐度在34.50‰以上,水深80米以上的海区。  相似文献   
2.
为了提高生物表面活性剂的表面活性,通过单因素及正交试验对已筛选的产生物表面活性剂芽孢杆菌的培养基及培养条件进行了优化,优化后的培养基成分为可溶性淀粉20 g/L,氯化铵2 g/L,KH2PO46 g/L,K2HPO42 g/L,MgSO4.7H2O 0.3 g/L,NaCl 2 g/L,CaCl20.08 g/L,EDTA 0.4 g/L。培养条件为4%接种量,种龄16 h,初始pH7,培养温度37℃,摇床转速160 r/min,发酵48 h。优化发酵条件后,发酵液表面张力由初始67.5 mN/m降低至24.8 mN/m,生物表面活性剂产量达到1.08 g/L。  相似文献   
3.
Some fungi are able to control and remediate arsenic (As)-contaminated soil, sediment, or water. Here, we investigate potential accumulation and volatilisation of As by three fungi strains. Results indicated that the highest level of As was accumulated by Penicillin janthinellum with 39.54 μg after 10 days in the culture system amended with 2,500 μg As(V), which represents 50 mg/l As. Fusarium oxysporum showed the highest amount of volatilised As with 304.06 μg after 15 days. The As content in the treated system (filter paper + As + fungi) was significantly higher than that in the control (filter paper + As; filter paper + fungi; filter paper). Trichoderma asperellum and F. oxysporum showed superior abilities for the absorption of extracellular As and accumulation of intracellular As, which accounted for 82.2 and 63.4% of the total accumulated As, respectively. However, P. janthinellum presented an equal distribution of intracellular and extracellular As. Scanning electron microscope (SEM) analysis suggested that little impact on mycelium growth of the three fungal strains was seen after exposure to 50 mg/l As(V) for 5 days, while the growth of fungi in the control was inhibited. The present results demonstrate that P. janthinellum, F. oxysporum, and T. asperellum would be expected to tackle As-contaminated environments.  相似文献   
4.

Background

Candidemia is one of the most common nosocomial bloodstream infections. Early diagnosis and antifungal treatment improve clinical outcomes in some studies but not all, with diverse data reported from different institutions. Similarly, antifungal resistance is more common in the USA than in Europe, but there is little data regarding the microbiology and clinical course of candidemia in adult patients in Asia.

Aims

(1) To capture species distribution and drug resistance rates among Candida bloodstream isolates, (2) to describe clinical features of candidemia, and (3) to identify factors associated with all-cause mortality, with emphasis on early initiation of antifungal treatment, at a large tertiary University Hospital in China.

Methods

In this single-center retrospective study, we identified all patients with candidemia, between 2008 and 2014. Demographic and clinical characteristics, microbiological information, details of antifungal therapy and clinical outcomes were collected.

Results

We studied 166 patients. 71 (42.8%) had cancer. Candida albicans was the most frequent species (37.3%), followed by C. parapsilosis (24.1%), C. tropicalis (22.8%), and C. glabrata (14.5%). Antifungal resistance was more frequent in non-albicans strains and especially C. glabrata. Twenty patients received inappropriate treatment with all-cause mortality of 35%. The remaining 146 patients had significantly lower mortality (21.9%, P?=?0.045). Among patients who received antifungal treatment, mortality rate increased with time to appropriate antifungal therapy (AAT): 13.7%, for?<?24 h, 21.1% for 24–48 h, 23.1% for?>?48 h, and 32.4% among patients who received no AT (χ2 for trend P?=?0.039). Initiating AAT more than 24 h after blood culture collection was an independent risk factor for mortality, after adjustment for other confounders (OR 7.1, 95% CI 1.3–39.4, P?=?0.024).

Conclusions

Candida albicans was the most frequent cause of candidemia at a large tertiary hospital in China, but antifungal resistance is a growing concern among non-albicans Candida species. The mortality rate of patients treated with ineffective antifungal agents based on in vitro susceptibilities was similar to that of patients who received no treatment at all, and delayed initiation of antifungal treatment was associated with increased risk of death.
  相似文献   
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6.
Yang  Gang  Wang  Huanyu  Feng  Mengyu  You  Lei  Zheng  Lianfang  Zhang  Taiping  Cong  Lin  Zhao  Yupei 《中国科学:生命科学英文版》2019,62(6):791-806
Pancreatic cancer is one of the most lethal human malignancies, partly because of its propensity for metastasis. However, highly metastatic human pancreatic cancer cell lines suitable for studies of metastasis are currently lacking. Here we established two highly metastatic human pancreatic cancer cell lines, MIA PaCa-2 In8 and Panc-1 In8, by Matrigel induction assay. The cell lines were further characterized both in vitro and in vivo. MIA PaCa-2 In8 and Panc-1 In8 cells demonstrated increased migration and invasion compared with their respective parental cells. Following injection into nude mice, MIA PaCa-2 In8 and Panc-1 In8 cells resulted in more pulmonary metastases compared with the parental cells. Furthermore, analyses of m RNA, long non-coding RNA, micro RNA, and methylation profiling revealed that these factors were aberrantly regulated in the highly metastatic cells,indicating that they probably affected metastasis. We thus established and characterized two highly metastatic human pancreatic cell lines that could be used as valuable tools for future investigations into the pathogenesis, metastasis, and potential treatment of human pancreatic cancer.  相似文献   
7.
以人胰高糖素样肽-1(human glucagons-like peptide-1,GLP-1))为研究对象,以克隆载体pPblu2SKP/(GLP-1A2G)2基因为模板,利用PCR扩增获得GLP-1与其突变体GLP-1A2G的编码基因,并将其插入原核表达质粒pGEX-4T-1中,利用氯化钙法将其转入表达宿主大肠杆菌(Escherichia coli)BL21(DE3)中诱导表达,经IPTG诱导后,收集菌体。菌体经超声破碎后,裂解液用GST亲和层析纯化得到融合蛋白,经凝血酶酶解,用Superdex G-75凝胶层析,得到GLP-1及其突变体GLP-1A2G的样品,经SDS-PAGE电泳测定,样品纯度〉90%。小鼠糖耐量试验表明,相对于空白对照组而言,GLP-1及其突变体GLP-1A2G可以明显地控制血糖的水平,两者的生物活性并无明显差异。由于突变体GLP-1A2G较GLP-1可以更加有效的抵制DPPⅣ的降解,提示突变体GLP-1A2G较GLP-1在白蛋白融合或PEG修饰等方面具有更大的优势。  相似文献   
8.
9.
吴璟  杨莲芳  姜小三  李强  王备新 《生态学报》2008,28(3):1183-1191
土地利用/覆被变化对溪流生态系统的影响是溪流生态学研究的热点.生物完整性是诊断溪流生物学状况和生态健康的重要指标.目的是研究西苕溪流域内土地利用类型对大型底栖无脊椎动物完整性(B-IBI)的影响.利用2003年西苕溪TM数据和DEM模型计算了62个样点上游3种空间尺度下(亚流域、沿岸和局部)的土地利用类型.结果表明,耕地,民居和竹园在流域中的百分比与B-IBI负相关,耕地百分比对B-IBI的影响在亚流域(r=-0.527,p<0.001),河岸(r=-0.665, p<0.001)和局部(r=-0.696, p<0.001)尺度上均显著.针叶林,阔叶林和混交林百分比与B-IBI正相关.阔叶林百分比在亚流域(r=0.333,p<0.001),河岸(r=0.589 ,p<0.001)和局部尺度(r=0.618,p<0.001)与B-IBI显著相关.而针叶林百分比仅在亚流域尺度(r=0.366,p<0.001)与B-IBI显著相关.在研究流域内耕地百分比小于50%的情况下,B-IBI并非随着耕地百分比的增长而线性下降,而是在达到一定阀值后(亚流域尺度,27%;河岸尺度,57%;局部尺度,59%)耕地的影响逐渐趋缓.在耕地百分比小于阀值前,B-IBI在局部尺度上与耕地百分比的增长的关系最强(r=-0.808, p<0.001, n=46).建议在沿岸区增加阔叶林,针叶林与混交林的占有率,或者建立耕地与溪流间的林地缓冲带,有助于保护和恢复西苕溪生态健康.  相似文献   
10.
广西食植瓢虫属五新种:鞘翅目:瓢虫科   总被引:2,自引:0,他引:2  
本文记述采自广西的食植瓢虫属Epilachna5新种,即花端食植瓢虫Epilachna anthodea,sp.nov。,短叶食植瓢虫E.brachylodb,sp.nov。浪平食植瓢虫E.langpingensis,sp.nov.,靴管食植瓢虫E.ocreata,sp.nov.和管刺食植瓢虫E;siponechinulata,sp.nov.。  相似文献   
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