球根海棠离体培养的形态发生研究

 球根海棠外植体可在同一条件下同时诱导不定芽和胚状体, 经间接途径和直接途径的体细胞胚胎发生频率均很高, 体细胞胚为单细胞起源或多细胞起源。以再生嫩叶为继代中间体, 在较高温度(28 ℃) 下诱导, 可建立高效扩繁体系。纵切芽丛继代形成大量愈伤组织, 愈伤组织继代半年后几乎完全丧失分化能力, 发生激素驯化作用, 而且愈伤组织细胞染色体数目已发生广泛变异。     

青海省干旱预警服务系统设计与建立

在阐述青海省干旱概念、类型、成因与评估指标的基础上,确定了旱情监测区域。以地面常规监测、气候监测和空间遥感监测相结合为基础,设计和建立了"监测—评估—预测、预警"信息业务系统,可为研究干旱发生规律,及时监测和预测干旱的发生,评估干旱程度以及制定防灾、减灾、救灾提供科学依据。     

利用人工增雨为农田需水服务的信息系统框架

针对我国北方地区水资源严重短缺、农田水分供需矛盾日益尖锐的现状 ,提出了首选人工增雨为农田补水的思路 ,并初步设计了一个利用人工增雨为农田需水服务的农田需水信息系统框架。     

相似离度的沙尘暴预报业务系统

选择1988年以来ECMWF资料齐全的沙尘暴个例,将其按区域分为全区、西部、中部、中西部以及中东部5类,再按强弱分别分为强和一般2类,建立不同的样本库。根据多年预报经验建立消空指标,对实时资料进行消空,在消空的基础上,用相似离度分析方法对ECMWF的3个场(500hPa高度场、850hPa温度场和海平面气压场)的历史资料库和实时资料进行比较,制作不同时次的沙尘暴预报。并利用VB和Fortran语言编程,建立沙尘暴预报业务系统,用人机交互的方式完成预报的制作,实现预报结果在Micaps系统下的自动显示。     

北京春季沙尘天气特征和预报

根据北京地区资料分析了沙尘的年代变化、月变化,春季是沙尘天气的高发期并以浮尘和扬沙为主。造成沙尘天气的冷空气主要有三条路径,它与蒙古气旋、冷锋、高空急流等大尺度天气系统紧密相连。     

专家系统在植保上的应用

专家系统在植保上主要应用于病虫害诊断、预测预报、决策管理等领域。植保专家的特点是应用范围广、实用性增强、新技术和新方法不断应用、有向综合性系统发展的趋势。文中还对植保专家系统存在的问题和发展对策进行了讨论。     

云南省小麦条锈病流行体系的研究现状

对云南省小麦条锈病的发生危害、流行特点、条锈菌越夏规律、品种及小种变异、环境因素等流行体系作 了较为详细的叙述,并针对各个环节提出综合防治策略。     

Advances in studying the differentiation into neurons of mesenchymal stem cells and their application

Mesenchymal stem cells (MSCs) are a population of multipotent cells that can proliferate and differentiate into marrow and non-marrow cell types, such as adipocytes, chondrocytes, myocytes, and so on. In recent years, many researchers have studied whether MSCs are capable of differentiation into neurons in vivo and ex vivo. The result that MSCs-derived neurons express NSE and NF, but don't express GFAP suggests MSCs can differentiate into neurons, some researchers have achieved success in promoting functional recovery in Pakinsons and transactional spinal cord injury rat models by use of MSCs-derived neurons. Therefore, MSCs-derived neurons will play an important role in the therapy for a variety of diseases of the nervous system.     

猪瘟病毒E2(gp55)基因在昆虫细胞中的表达

将除去3'端跨膜区的猪瘟病毒E2基因亚克隆到杆状病毒转移载体pFastBacHTb,获得重组质粒pFBHT-E2,转化进含穿梭载体Bacmid的感受态细胞DH10Bac,发生转座作用,经抗性及蓝白斑筛选得到含E2基因的重组载体质粒rBacmid-E2,以脂质体介导的方法将此重组载体质粒转染sf9昆虫细胞,获得重组病毒,命名为rvBac-E2.经SDS-PAGE和Western-blot及ELISA等方法检测,结果表明,此E2基因在昆虫细胞中正确表达,表达的蛋白能与猪瘟阳性血清发生特异性反应.     

Magnetic resonance imaging of a brain abscess in a 10-month-old filly

The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a capsule is highly diagnostic of a mature brain abscess. The lesion seen on MR images was confirmed at necropsy where a large abscess of the right hemisphere was observed. Streptococcus zooepidemicus and Pseudomonas aeruginosa were isolated from the abscess. Based on histopathologic examination, the signal characteristics of the capsule on T1-weighted and T2-weighted images were found to be due to the presence of numerous hemosiderin-laden macrophages. These results are in agreement with previous studies on human patients. This report confirms the value of MRI in the diagnosis of equine brain diseases.