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791.
We investigated whether decreases in circulating polymorphonuclear neutrophils (PMN) during lethal Escherichia coli (E. coli) sepsis in canines are related to insufficient host granulocyte colony-stimulating factor (G-CSF). Two-year-old purpose-bred beagles had intraperitoneal E. coli-infected or -noninfected fibrin clots surgically placed. By 10 to 12 h following clot, both infected survivors and nonsurvivors had marked increases (P = 0.001) in serum G-CSF levels (mean peak G-CSF ng/ml +/- SE, 1,931 +/- 364 and 2,779 +/- 681, respectively) compared with noninfected controls (134 +/- 79), which decreased at 24 to 48 h. Despite increases in G-CSF, infected clot placement caused delayed (P = 0.06) increases in PMN (mean +/- SE change from baseline in cells x 10(3)/mm(3) at 24 and 48 h) in survivors (+3.9 +/- 3.9 and +13.8 +/- 3.6) compared with noninfected controls (+13.1 +/- 2.8 and +9.1 +/- 2.5). Furthermore, infected nonsurvivors had decreases in PMN (-1.4 +/- 1.0 and -1.1 +/- 2.3, P = 0.006 compared with the other groups). We next investigated whether administration of G-CSF immediately after clot placement and continued for 96 h to produce more rapid and prolonged high levels of G-CSF after infection would alter PMN levels. Although G-CSF caused large increases in PMN compared with control protein from 2 to 48 h following clot in noninfected controls, it caused much smaller increases in infected survivors and decreases in infected nonsurvivors (P = 0.03 for the ordered effect of G-CSF comparing the three groups). Thus insufficient host G-CSF is unlikely the cause of decreased circulating PMN in this canine model of sepsis. Other factors associated with sepsis either alone or in combination with G-CSF itself may reduce increases or cause decreases in circulating PMN.  相似文献   
792.
The fibrillin-1 (FBN1) gene mutations result in Marfan syndrome (MFS) and have a variety of phenotypic variations. This disease is involved in the skeletal, ocular and cardiovascular system. Here we analyzed genotype-phenotype correlation in two Chinese families with MFS. Two patients with thoracic aortic aneurysms and dissections were diagnosed as MFS according to the revised Ghent criteria. Peripheral blood samples were collected and genomic DNAs were isolated from available cases, namely, patient-1 and his daughter and son, and patient-2 and his parents. According to the next-generation sequencing results, the mutations in FBN1 were confirmed by direct sequencing. A heterozygous frameshift mutation in exon 12 of FBN1 was found in the proband-1 and his daughter. They showed cardiovascular phenotype thoracic aortic aneurysms and dissections, a life-threatening vascular disease, and atrial septal defect respectively. One de novo missense mutation in exon 50 of FBN1 was identified only in the patient-2, showing aortic root aneurysm and aortic root dilatation. Intriguingly, two novel mutations mainly caused the cardiovascular complications in affected family members. No meaningful mutations were found in these two patients by screening all exons of 428 genes related with cardiovascular disease. The high incidence of cardiovascular manifestations might be associated with the two novel mutations in exon 12 and 50 of FBN1.  相似文献   
793.
在实验室中以转cry1Ab基因水稻 克螟稻 1号为材料 ,研究了不同温度下Bt水稻对二化螟Chilosuppressalis (Walker) 3龄和 5龄幼虫取食、生长及其存活的影响。结果表明 ,不同温度下 3龄和 5龄幼虫取食Bt水稻后 ,其取食量、体重增长和存活率均极显著低于对照。温度对 3龄幼虫取食、生长和存活无显著影响 ,但对 5龄幼虫的取食和体重增长则有显著影响。幼虫死亡率与其取食Bt水稻的累积食量间存在着正相关关系。  相似文献   
794.
全球氮沉降对生态系统造成了深远的影响,研究长时间氮沉降对草地生态系统土壤理化特征的影响有助于加强生态系统对氮沉降响应的长效机制的理解。通过连续14年长期施加N0(0 g N m-2 a-1)、N2(2 g N m-2 a-1)、N4(4 g N m-2 a-1)、N8(8 g N m-2 a-1)、N16(16 g N m-2 a-1)、N32(32 g N m-2 a-1)六种浓度尿素模拟氮沉降,并将土壤分成0-10、10-20和20-40 cm三个深度土层,研究温带草原生态系统土壤碳氮组分及物理结构对氮添加的响应及其相互关系,结果表明:(1)氮添加显著降低0-10 cm土壤酸碱度及土壤微生物量碳含量,N32相比N0分别下降了27.63%和58.40%(P<0.05);各土层总有机碳和全氮含量对氮添加处理无显著响应,0-10 cm土层显著高于20-40 cm土层。(2)同一土层深度不同梯度氮添加处理显著增加土壤无机氮离子含量(P<0.05),0-10 cm土层铵态氮含量N32相比N0增加了88.72%,20-40 cm土层硝态氮含量N32相比N0增加了19.55倍,土壤深度与氮添加对无机氮离子含量影响具有显著的交互效应。(3)同一土壤深度不同梯度氮添加处理土壤粒度分形维数及土壤团聚体差异不显著,相关分析表明土壤碳氮元素含量与土壤结构显著相关。土壤碳氮组分在适宜浓度氮添加的增加趋势说明氮添加在一定程度上可能促进土壤理化性质的改良,氮添加对土壤物理结构的影响还需要进一步的深入研究。  相似文献   
795.
Archives of Microbiology - Severe acute respiratory syndrome virus 2 (SARS-CoV-2) belongs to the single-stranded positive-sense RNA family. The virus contains a large genome that encodes four...  相似文献   
796.
Radiotherapy is one of the most important treatments for chest tumours. Although there are plenty of strategies to prevent damage to normal lung tissues, it cannot be avoided with the emergence of radiation‐induced lung injury. The purpose of this study was to investigate the potential radioprotective effects of glucosamine, which exerted anti‐inflammatory activity in joint inflammation. In this study, we found glucosamine relieved inflammatory response and structural damages in lung tissues after radiation via HE staining. Then, we detected the level of epithelial‐mesenchymal transition marker in vitro and in vivo, which we could clearly observe that glucosamine treatment inhibited epithelial‐mesenchymal transition. Besides, we found glucosamine could inhibit apoptosis and promote proliferation of normal lung epithelial cells in vitro caused by radiation. In conclusion, our data showed that glucosamine alleviated radiation‐induced lung injury via inhibiting epithelial‐mesenchymal transition, which indicated glucosamine could be a novel potential radioprotector for radiation‐induced lung injury.  相似文献   
797.
采用药膜法分别测定了10%甲维盐·茚虫威悬浮剂、12%甲维盐·虫螨腈悬浮剂、12%虫螨腈·虱螨脲悬浮剂、14%呋虫胺·螺虫乙酯悬浮剂、22%吡虫啉·螺虫乙酯悬浮剂和6%吡虫啉·高效氯氟氰菊酯悬浮剂6种复配杀虫剂对七星瓢虫Coccinella septempunctata Linnaeus幼虫急性毒性,并进行了初级风险评...  相似文献   
798.
针对白蚁防治药剂联苯菊酯传统加工剂型存在的安全性差、持效期短等缺点,采用溶剂蒸发法制备联苯菊酯微胶囊.通过粒径大小、外观形貌、包封率以及载药量筛选出最佳芯壁比、乳化剂用量和剪切时间,并对微胶囊理化特性及释放性能进行表征,同时考察微胶囊对白蚁的杀灭效果和持效性.研究结果表明,芯壁比为1:1.5,乳化剂用量为7%,剪切时间为6 min时制备的联苯菊酯微胶囊粒径适中(97.6μm),包封率高达70.5%,缓释性能良好,与市售乳油相比,对白蚁的杀灭效果相当,但持效性能优异.该研究获得的联苯菊酯微胶囊为安全、高效防治白蚁提供了技术手段.  相似文献   
799.
Mei  Jingxia  Zhang  Nan  Yu  Yuanyuan  Wang  Qiang  Yuan  Jiugang  Wang  Ping  Cui  Li  Fan  Xuerong 《Applied microbiology and biotechnology》2018,102(21):9159-9170

Proteases can cause unacceptable fiber damage when they are singly applied to wool anti-felting treatment which can make wool textiles machine-washable. Even if protease is attached by synthetic polymers, the modified protease plays a limited role in the degradation of keratin with dense structure consisting of disulfide bonds in the scales. Here, to obtain “machine-washable” wool textiles, a novel “trifunctional protease” with reducibility, hydrolysis, and localization is developed by means of covalent bonding of protease molecules with poly (ethylene glycol) bis (carboxymethyl) ether (HOOC-PEG-COOH) and l-cysteine using carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling, aiming at selectively degrading the scales on the surface of wool. The formation of polymer is confirmed with size exclusion chromatography (SEC) and Fourier transform infrared spectroscopy (FT-IR). Ellman’s test and fluorescence microscopy reveal that the modified protease can reduce disulfide bonds and restrict hydrolysis of peptide bonds on the wool scales. Furthermore, when applied to wool fabrics, the modified protease reach better treatment effects considering dimensional stability to felting (6.12%), strength loss (11.7%) and scale dislodgement proved by scanning electron microscopy (SEM), alkali solubility, wettability, and dyeability. This multifunctional enzyme is well-designed according to the requirement of the modification of wool surface, showing great potential for eco-friendly functionalization of keratin fibers rich in disulfide linkage.

  相似文献   
800.
【目的】创伤弧菌是致死率最高的弧菌物种,但目前尚无在全基因组层面挖掘毒力相关因子的研究。本研究以创伤弧菌分离来源(临床和环境)作为不同表型,通过与260株基因组序列进行关联分析,挖掘毒力相关因子,从而进一步了解创伤弧菌致病因素。【方法】对139株创伤弧菌分离株进行高通量测序,获取其全基因组序列;与公共数据库已公开发表的121株基因组整合,使用pyseer软件进行全基因组关联分析,对与不同分离来源显著相关的基因进行注释和解读。【结果】共发现11个基因与临床分离株显著相关,其中9个是本研究新发现的创伤弧菌潜在毒力相关因子。【结论】本研究使用群体基因组学和统计遗传学方法,在全基因组范围扫描挖掘了创伤弧菌毒力相关因子,为深入揭示该物种致病机制、设计新的疫苗和治疗靶点提供了重要依据。  相似文献   
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