大鼠烫伤后延髓孤束核β－内啡肽含量的变化及其抗血清的作用

大鼠背部２０％体表面积接触沸水２０ｓ,形成Ⅲ度烫伤后,延髓孤束核推挽灌流液中β－内啡肽免疫活性物质的含量显著升高,在烫后１、４ｈ两次达到峰值。烫后立即向弧束核微量注射０．４μｌβ－内啡肽抗血清（滴度１：３００００）,可在一定程度上改善心功能指标,延缓血压和心率的下降,但未能延长动物的存活时间。提示孤束核的β－内啡肽在烫伤休克的病理过程中起作用,其含量的过量升高有抑制心血管功能的作用,从而不利于烫伤休克的恢复。     

Maturation and fertilization of porcine oocytes in vitro

Four experiments were conducted to study 1) factors affecting porcine oocyte maturation in culture medium and 2) a new method for oocyte maturation outside the porcine body. In Experiment 1, five groups of oocytes were cultured in m-TCM199 or m-KRB medium for 24 to 28, 32 to 36 or 40 to 42 hours and then were fertilized in vitro. The cleavage rate (two to four-cell stage) of oocytes cultured for 32 to 36 hours was significantly higher than those of the other oocytes. The results indicate that a suitable culture period for the in vitro maturation of porcine oocytes is 32 to 36 hours. In Experiment 2, four groups of oocytes were cultured in m-KRB or m-KRB supplemented with PFF, PMSG or FSH for in vitro maturation, and the cleavage rates of oocytes were 7.94, 22.56, 30.23 and 23.26%, respectively, after in vitro fertilization. The results show that porcine follicular fluid (PFF) and gonadotrophins added to the culture medium promote porcine oocyte maturation in vitro. In Experiment 3, oocytes were cultured in m-KRB or m-TCM199, supplemented with both gonadotrophin and pocine folliclar fluid for maturation in vitro. After fertilization in vitro, the cleavage rates of oocytes were 26.32 and 27.93% for the two media. The results indicate that the difference between m-KRB and m-TCM199 was insignificant when the media were used to culture porcine oocytes. But there was a significant difference when PFF and gonadotrophins were added to the basic media. In Experiment 4, porcine oocytes were transferred into the reproductive tracts of other animals for maturation. After 34 to 36 hours, the oocytes were collected and fertilized in vitro. The cleavage rates of oocytes were 10.42, 28.45, 3.33 and 36.36%, respectively, for the oocytes matured in mouse uterine horns, rat uterine horns, rat oviducts or rabbit oviducts. The results show that porcine oocytes can be matured in the reproductive tracts of other animals.     

自然保护区管理中生态与娱乐属性的权衡:一个选择实验的应用

随着自然保护区多样化的发展以及旅游需求的日益增长,保护区管理者面临着保护生态环境与满足娱乐需求的双重压力,这使得保护区管理者需要更多的信息进行决策。以中国东北部的扎龙国家级自然保护区为例,进行了一项选择实验,选取生物多样性、预期游客数量、景区的环境教育设施、门票价格等4个属性,分别采用多项logit模型、随机参数logit模型和潜在分类模型,探究游客在可能存在冲突的管理优先级之间的偏好。目的是揭示游客如何评价保护区不同的管理属性,以及各属性的边际支付意愿和偏好,并根据这些信息制定有效的保护区管理指南。研究结果表明生物多样性是保护区游客最关注的属性,并且游客对于生态属性的关注度高于娱乐属性。因此,保护区管理者应首先维持并改善生物多样性及其生态环境,在不破坏生态环境的基础上开发具有环境教育作用的娱乐服务。此外,研究发现游客可分为生态友好型和价格敏感型两种类别,不同类型的群体对游览保护区存在不同偏好,女性和年轻的受访者对生态更友好,男性和年长的受访者对价格更敏感。本文的贡献是将某一方面属性价值的描述扩展到涵盖多个管理属性的研究,并为保护区管理中生态与娱乐的权衡问题提供了更具体的见解。     

Systematic Evaluation of Protein Sequence Filtering Algorithms for Proteoform Identification Using Top‐Down Mass Spectrometry

Complex proteoforms contain various primary structural alterations resulting from variations in genes, RNA, and proteins. Top‐down mass spectrometry is commonly used for analyzing complex proteoforms because it provides whole sequence information of the proteoforms. Proteoform identification by top‐down mass spectral database search is a challenging computational problem because the types and/or locations of some alterations in target proteoforms are in general unknown. Although spectral alignment and mass graph alignment algorithms have been proposed for identifying proteoforms with unknown alterations, they are extremely slow to align millions of spectra against tens of thousands of protein sequences in high throughput proteome level analyses. Many software tools in this area combine efficient protein sequence filtering algorithms and spectral alignment algorithms to speed up database search. As a result, the performance of these tools heavily relies on the sensitivity and efficiency of their filtering algorithms. Here, we propose two efficient approximate spectrum‐based filtering algorithms for proteoform identification. We evaluated the performances of the proposed algorithms and four existing ones on simulated and real top‐down mass spectrometry data sets. Experiments showed that the proposed algorithms outperformed the existing ones for complex proteoform identification. In addition, combining the proposed filtering algorithms and mass graph alignment algorithms identified many proteoforms missed by ProSightPC in proteome‐level proteoform analyses.     

鱼类肌肉生长抑制素研究进展

肌肉的分化、生长和发育是动物生长发育的重要环节和过程,肌肉也是动物为人类提供的食品的主要成分。肌肉的生长和发育在不同层次受许多因素的影响,如环境(气候、营养等因素) 、激素和分子水平的调控。       

白酒可培养微生物数据库构建

【目的】白酒可培养微生物的分离筛选是白酒行业重要的研究内容,本文旨在构建中国白酒生产环境中可培养微生物信息数据库。【方法】数据库信息主要来源于通过人工查阅和整理目前已发表的白酒微生物的相关的文献报道和菌种保藏中心相关的筛选自白酒生态系统的微生物信息。数据库主要设计3个功能:(1)白酒可培养微生物信息检索:通过菌株名称、分离位置、培养基、代谢产物等为条件检索相关的白酒可培养微生物信息,从而获取该白酒微生物详细的生理生化与分类学信息;(2)培养基信息检索:通过特定培养基成分,培养基编号和名称检索相关的培养基信息,包括培养的组成和配制方法。(3)数据更新:在线上传新的可培养微生物和培养基信息。【结果】目前数据库共收1221种白酒可培养微生物和295种培养基信息,网址为:http://cmbaijiu.i-sanger.com/。【结论】本数据库是我国白酒领域首个可培养微生物信息的数据库,将有助于白酒微生物培养的相关研究工作开展。     

Karyotyping of comparative genomic hybridization human metaphases by using support vector machines.

BACKGROUND: Comparative genomic hybridization (CGH) is a relatively new molecular cytogenetic method for detecting chromosomal imbalance. Karyotyping of human metaphases is an important step to assign each chromosome to one of 23 or 24 classes (22 autosomes and two sex chromosomes). Automatic karyotyping in CGH analysis is needed. However, conventional karyotyping approaches based on DAPI images require complex image enhancement procedures. METHODS: This paper proposes a simple feature extraction method, one that generates density profiles from original true color CGH images and uses normalized profiles as feature vectors without quantization. A classifier is developed by using support vector machine (SVM). It has good generalization ability and needs only limited training samples. RESULTS: Experiment results show that the feature extraction method of using color information in CGH images can improve greatly the classification success rate. The SVM classifier is able to acquire knowledge about human chromosomes from relatively few samples and has good generalization ability. A success rate of moe than 90% has been achieved and the time for training and testing is very short. CONCLUSIONS: The feature extraction method proposed here and the SVM-based classifier offer a promising computerized intelligent system for automatic karyotyping of CGH human chromosomes.     

A multishear microfluidic device for quantitative analysis of calcium dynamics in osteoblasts

Reactive oxygen species (ROS) are an important factor in the development of skin lesions in diabetes. A new antioxidant, hydrogen, can selectively neutralize hydroxyl radicals (OH) and peroxynitrite (ONOO⁻) in cell-free systems, whereas it seldom reacts with other ROS. Fibroblasts are a key component of skin. In the present study, we investigated the protective effects of hydrogen-rich medium on human skin fibroblasts (HSFs) under oxidative stress. Confocal microscopy was used to assay both the intracellular superoxide anion () concentration and the mitochondrial membrane potential (ΔΨ). Cell viability was determined using the Cell Counting Kit-8 (CCK-8). The concentrations of cellular malonaldehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), 8-hydroxy-2′-deoxyguanosine (8-OHdG) and 3-nitrotyrosine (3-NT) were also measured. The results revealed that both mannitol and high glucose could cause oxidative stress in HSFs. Interestingly, the use of a hydrogen-rich medium significantly reduced the level of intracellular , stabilized the ΔΨ and attenuated production of MDA, 8-OHdG and 3-NT which efficiently enhanced the antioxidative defense system and protected the HSFs from subsequent oxidative stress damage. In other words, hydrogen decreased the excessive generation of intracellular and elevated the cellular antioxidative defense. Based on our results, hydrogen may have applications in the treatment of skin diseases caused by diabetes.     

基于选择实验的三江平原湿地生态系统服务功能价值评价及偏好异质性研究

维持与保护生态系统服务功能是实现可持续发展的基础,定量评价湿地生态系统服务功能的经济价值已成为当前生态学领域研究的前沿课题。以三江平原湿地为研究对象,应用选择实验法,选取湿地面积、生物多样性、水源涵养和自然景观等4项湿地属性,运用随机参数Logit模型(RPL)对其进行货币化评价,并结合潜在分类模型(LCM)证实并解释公众对湿地生态系统服务功能的偏好异质性。研究结果显示:湿地生态系统服务功能的价值依次为水源涵养湿地面积生物多样性自然景观。对于维持当前各项湿地生态系统服务功能的总价值为14.61亿元/a,改善价值为98.58亿元/a。此外,研究发现受访者可分为资源偏好型、景观偏好型和价格敏感型等3个潜在类别,不同类型的群体对湿地生态系统服务功能存在不同偏好;女性和更高学历的受访者更偏好于资源保护,高收入和到景区旅游次数多的受访者更偏好于景观保护,而教育和收入水平越低的受访者更倾向于选择价格较低的湿地管理方案。研究有助于湿地可持续管理政策的优化设计,为相关环境政策的制定提供理论依据。