普氏原羚粪便样品中皮质醇激素保存时效研究

由于采集粪便样品无需对目标动物进行捕捉、限制或影响其行为,检测粪便样品中类固醇激素的方法近几十年来在野生动物保护、行为生态学、生理生态学等诸多领域得到广泛应用。普氏原羚(Procapra przewalskii)由于其种群和行为等方面的特殊性,较难进行直接的生理监测,因此采用间接手段监测其粪便类固醇激素就显得很有必要。为探讨不同保存方法对普氏原羚粪便中皮质醇的影响,我们将采集到的新鲜粪便样品充分混合后分为30份,各取10份分别保存于﹣20℃、4℃和20℃,在保存2、5、7、10、15、20、25、30 d和50 d时,使用酶联免疫吸附测定法(ELISA)检测样品中的皮质醇含量。单因素方差分析(One-way ANOVA)结果显示,保存于﹣20℃的粪便样品中皮质醇含量在保存50 d内没有显著变化,含量为(11.747±2.951)ng/g(平均值±标准差),(F=1.966,n=81,P0.05),而保存于4℃和20℃的样品则出现明显波动(4℃:F=23.643,P0.05;20℃:F=35.126,P0.05),含量分别为(15.951±6.766)ng/g和(11.042±6.094)ng/g。保存于4℃和20℃的样品中皮质醇含量在24 h内均有上升,在随后的几天逐渐下降。结果表明,﹣20℃冷冻可以简便有效地保存普氏原羚粪便样品中的皮质醇激素。同时,在野外暴露超过24 h的粪便样品会造成测定结果产生误差,在采集样品时要考虑到潜在的影响。     

奶糖的样品前处理优化与微生物检测结果影响因素相关性讨论

本文的主要研究目的是找到针对不同奶糖样品最适合的前处理方法、快速有效的检测方法以及影响检测结果的相关性因素。通过溶化温度、溶化方式、溶化时间等不同实验条件,找出了能满足不同奶糖菌落总数检测要求的样品前处理方法,即将25 g奶糖样品称取到预温至45℃的225 m L灭菌生理盐水中,在45℃气浴恒温振荡器中以220 r/min振荡11 min,使奶糖完全溶化。同时由于奶糖中有些菌落会蔓延生长,为了不影响计数结果,在倾入平板计数琼脂培养基冷却后再在其表面覆盖一层5 m L培养基抑制菌落蔓延,对抑制效果不佳的使用光学放大菌落计数器计数,以保证最终检测结果的准确性。不同奶糖中水分、营养含量及pH相差不大,实验结论表明与其菌落总数检测结果高低无相关性。通过36℃培养24 h与48 h菌落总数检测结果没有明显差异,可以将培养24 h的检测结果作为参考。     

一株降解苯酚的酵母菌的分离与特性

从炼油厂消化污泥中分离到一株酵母菌(Saccharomyces sp.)。该菌能在以苯酚为唯一碳源的培养基上生长。菌落较小,表面不光滑四周呈树枝状,生长的温度范围为25～35℃,生长的pH范围为6—9。在以苯酚为唯一碳源时,能生长的最高酚浓度为1850ppm,蛋白胨、酵母粉能促进酵母菌的生长和降解,且能使酵母菌的耐酚浓度提高到2400ppm。葡萄糖能促进酵母菌的生长。但抑制苯酚的降解。此酵母菌还能利用苯甲酸钠、间苯二酚和油酸。     

不同施肥处理玉米根际微生物种群结构及代谢多样性

目的探究不同施肥处理对玉米根际微生物种群结构及代谢多样性的影响。方法以生物菌肥(样品1)、复合肥(样品2)、有机肥(样品3)、生物菌肥+复合肥(样品4)、生物菌肥+有机肥(样品5)、复合肥+有机肥(样品6)和不施肥(对照)共7个处理为研究对象,利用活菌计数法测定种群结构,同时利用Biolog技术对样品进行检测,通过SPSS数据分析软件对测得的数据进行分析。结果与对照相比,样品1中细菌、酵母菌、霉菌和放线菌的数量均有所增加,其中酵母菌增加最多,每克土壤增加了1.37×10~6个;施肥处理使微生物的代谢多样性也有所增加,样品1的平均每孔颜色变化率(AWCD值)增长率最大,多样性指数(H)、均匀度指数(E)、丰富度指数(R)均增加,但优势度指数(D)降低,说明样品1的菌群多样性最高,物种数目最多,能够提高土壤的养分和肥力。结论本研究所得结果为农业生产中玉米肥料的选择及最佳配比方法提供数据。     

猪白细胞介素-2和融合抗菌肽重组酵母菌构建及其对小鼠免疫和生长的协同效应

为了开发经济实用的新型免疫调节剂,以2A自剪切技术构建重组毕赤酵母Pichiapastoris共同表达猪白细胞介素-2(IL-2)和融合抗菌肽基因,然后以重组基因工程酵母菌饲喂ICR小鼠,以实时荧光定量PCR、ELISA和流式细胞计数评估其对小鼠免疫力和生长的影响。实验结果显示,处理组(融合抗菌肽重组酵母菌、IL-2和融合抗菌肽重组酵母菌)小鼠的生长明显优于对照组(空质粒酵母菌)(P 0. 05),且血清Ig G、Ig G1和Ig G2a含量显著升高(P 0. 05); TLR1、TLR4、TLR6、TLR9、IL-7、IL-15、IL-23、CD62L、IL-2、IL-4、IL-6、IL-12、CRP4和CAMP基因的表达水平显著增加(P 0. 05)。同时,处理组小鼠血液白细胞Th和Tc细胞明显增多(P 0. 05),免疫力和存活率均明显高于对照组(P 0. 05)。重组酵母菌能有效增强小鼠的先天和获得性免疫力,促进生长,可进一步开发成安全有效的免疫调节生物制剂,改善动物的生长和免疫力。     

样品预处理对HCV-cAg酶联免疫吸附试验特异性的影响

目的:探讨血液样品预处理后对控制酶联免疫吸附试验中假阳性的效果.方法:向稀释血清样品中加入适量的C2H6OS和IgM抗体后,以HCV-cAg酶联免疫方法检测60份血清样品中丙型肝炎病毒核心抗原的阳性情况;与常规样品处理方法和逆转录-聚合酶链反应(RT-PCR)检测结果为标准进行比较分析.结果:60份血清样品,采用常规的样品处理方法检测出的阳性例数为34例,假阳性率迭25%;采用改良法检测出的阳性例数为23例,假阳性率达6.7%,二者相比差别具有统计学意义(P(≦) 0.05).结论:改良法血清样品预处理可提高ELISA法检出丙型肝炎病的特异性.     

田间施药对自然发酵葡萄酒酵母菌群落结构的影响

【背景】酵母菌是葡萄酒发酵过程中一类非常重要的微生物,其多样性及群体组成对葡萄酒的质量有重要贡献。影响葡萄酒中酵母菌组成的因素有很多,但目前尚未见葡萄园田管理对葡萄酒酵母菌群落结构影响方面的报道。【目的】探索田间施药对自然发酵葡萄酒酵母菌群落结构的影响。【方法】采用分离培养、常规分子生物学鉴定和Illumina MiSeq宏基因组测序结合的方法分析不同样品中的酵母菌群落结构情况。【结果】从不使用内吸收型化学农药的葡萄样品自然发酵液中分离鉴定出Pichia、Hanseniaspora、Schizosaccharomyces、Candida、Saccharomyces、Zygoascus、Issatchenkia等7个属8个种的酵母菌,宏基因组测序结果表明有Pichia(29.42%)、Saccharomyces(21.91%)、Issatchenkia(17.99%)、 Hanseniaspora(12.10%)、 Candida(7.47%)、 Zygosaccharomyces(5.32%)、Schizosaccharomyces (3.07%)、Aureobasidium (0.29%)等属的酵母菌参与发酵;使用常规化学农药的葡萄样品自然发酵液中分离鉴定出Pichia、Hanseniaspora、Schizosaccharomyces、Candida、Cryptococcus等5个属6个种的酵母菌,宏基因组测序结果表明有Pichia (41.66%)、Hanseniaspora (21.54%)、Candida(19.11%)、 Zygosaccharomyces(7.78%)、 Schizosaccharomyces(4.04%)、 Cryptococcus(3.21%)、Saccharomyces (1.12%)、Aureobasidium (0.49%)等属的酵母菌参与发酵。【结论】两样品中酵母菌比例有显著差异,表明在酿酒葡萄的园田管理中化学农药的使用对自然发酵葡萄酒的酵母菌群落结构有较大影响。     

一种新组分酵母菌培养基的研制及应用

目的：研制一种酵母菌培养基用于快速准确测定食品中酵母菌数。方法：以麦芽汁为基料,加入大豆蛋白胨、酵母浸出粉、葡萄糖、可溶性淀粉,正交试验比较酵母菌生长情况来确定各组份含量。结果：MYSPA培养基最佳组成为：去除啤酒花的麦芽汁1000ml,大豆蛋白胨12.5g,酵母浸出粉7g,葡萄糖6g,可溶性淀粉10g。结论：酵母菌以灭菌L型涂布棒涂布在MYSPA培养基上,放置28℃培养48h计数菌落即可。     

一种检测储存喷气燃料中特征真菌的新方法——LAMP-LFD

利用环介导等温扩增(LAMP)与横向流动试纸快速检测技术(LFD)相结合,以Amorphotheca resinae的18S rRNA基因为靶序列,设计1套LAMP引物,建立了反应温度63℃、时间35 min。用喷气燃料中曾发现的4株真菌和A.resinae作为特异性试验菌株,LAMP-LFD法检测只有A.resinae呈阳性反应。A.resinae基因组DNA检测灵敏度为26 fg/μL;用已建立的LAMP-LFD方法对9个喷气燃料样品进行检测,其中有6个样品被检出存在A.resinae。结果表明该方法用于快速检测喷气燃料中的A.resinae耗时短、操作简便、特异性强、灵敏度高,有望用于为检测喷气燃料中特征真菌A.resinae的新方法。     

新疆地区酸马奶中酵母菌的鉴定及其生物多样性分析

从新疆少数民族牧民家庭采集的28份传统工艺酿造酸马奶样品中分离出87株酵母菌,并对其进行了生理生化鉴定、分子生物学鉴定和生物多样性分析。生化试验结果表明,新疆地区酸马奶中的酵母菌为Saccharomyces unisporus(占总分离株的48.3%),Kluyveromyces marxianus(27.6%),Pichia membranaefaciens(15.0%)和Saccharomyces cerevisiae(9.2%)。选取其中的6株酵母菌和1株参考菌株,进行大亚基(26S)rDNA D1/D2区域(600bp左右)碱基序列分析,并通过GenBank进行同源序列搜索以确定各菌株的归属,进一步验证生理生化方法的正确性。从得到的结果中可以看出,S.unisporus和K.marxianus为新疆地区酸马奶中的优势菌。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.