高速公路恢复中线的坐标放线法

高速公路施工过程中。中线恢复至关重要。本文介绍了一种与传统方法相比具有快速、准确、方便,而且不易受障碍物影响、无丈量累积误差的坐标放线法。并重点阐述了坐标放线法的原理。坐标计算的方法及发展前景。     

利用污水养殖微藻研究进展

微藻细胞中含有多种可利用的营养成分和化工原料,利用污水培养微藻在生产有价值藻体的同时净化污水,降低了养殖成本,使原本高成本的微藻养殖成为可能。该文从微藻可利用的污水类型及对污水的净化效率、适应污水生长的微藻种类、微藻的采收以及污水养殖得到的藻粉用途等方面的研究进展进行概述,并对未来污水养殖微藻需要继续研究的方向进行了展望。     

Research progresses on the pathophysiology of hemorrhoidal diseases

Various hypotheses have been put forward to explain the pathogenesis of hemorrhoidal diseases. However, the etiology and mechanisms of hemorrhoids are far from clear, and as a consequence the present therapeutic objective is just to relieve or abolish the symptoms of hemorrhoids. In this review, the recent research advances on the pathophysiological characteristics that are closely associated with hemorrhoids are analyzed and discussed, which include constipation, high anal resting pressure, anal mucosa damage, aging of the anal cushion supporting tissue, blood and vessel alterations, obstruction of microcirculation and biochemical changes.     

我国农业生产应重视质量目标定位

农业质量目标定位从市场角度看经济行为,从我国特殊国情看则是地农业的功能要求。在主要农产品逐步向买方过渡的环境下,定位数据与质量并重的农业发展目标,是保持我国农业持续、稳定、协高发展的前提条件。     

Converting restriction fragment length polymorphism to single‐strand conformation polymorphism markers and its application in the fine mapping of a trichome gene in cotton

A well‐characterized and systematically organized collection of genetic markers is crucial in the study of any crop species. It is the basis of map‐based gene cloning and crop improvements through marker‐assisted selections. Single‐strand conformation polymorphism (SSCP) has been a robust way of discovering new polymorphisms in marker development without the requirement of sequencing. Here, we report the first approach of applying SSCP marker discovery methods in the genetic map construction and gene mapping of cotton species. A total of 80 restriction fragment length polymorphism (RFLP) markers were selected from a region on published cotton genetic maps around the T1 gene related to cotton trichome. Among the 80 RFLPs, 28 showed polymorphisms through SSCP, showing a polymorphic rate of approximately 35%, which is much higher than that of simple sequence repeat (SSR) markers in the same region (7.8%). By integrating these newly generated SSCP markers, a detailed genetic map was reconstructed around this region using an F₂ population derived from a cross between Gossypium arboreum and G. herboceum. The reconstructed region comprises 22 SSCP markers, eight SSR markers and the T1 gene, spanning 21.6 cM. The marker order of the new map agrees well with published reference RFLP maps. The above results suggest that SSCP method can be applied very efficiently and reliably to the marker development of cotton genomes. It will prove to be even more valuable and robust after the public release of cotton whole‐genome sequences.     

Role for the membrane receptor guanylyl cyclase-C in attention deficiency and hyperactive behavior

Midbrain dopamine neurons regulate many important behavioral processes, and their dysfunctions are associated with several human neuropsychiatric disorders such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. Here, we report that these neurons in mice selectively express guanylyl cyclase-C (GC-C), a membrane receptor previously thought to be expressed mainly in the intestine. GC-C activation potentiates the excitatory responses mediated by glutamate and acetylcholine receptors via the activity of guanosine 3',5'-monophosphate-dependent protein kinase (PKG). Mice in which GC-C has been knocked out exhibit hyperactivity and attention deficits. Moreover, their behavioral phenotypes are reversed by ADHD therapeutics and a PKG activator. These results indicate important behavioral and physiological functions for the GC-C/PKG signaling pathway within the brain and suggest new therapeutic targets for neuropsychiatric disorders related to the malfunctions of midbrain dopamine neurons.     

香菇新菌株宁香8号选育初报

采用多孢分离技术产生多个新组合，经驯化筛选获得香菇新菌株宁香8号。宁香8号菌丝生长适温10－25℃，子实体生长适温10－23℃，菌丝生长期58－60d，室内栽培生物学效率达81．60％，室外栽培生物学效率达92．85％，宁香8号不仅适于阔叶木屑栽培，亦适公杉木屑袋栽。     

“七五”国家科技攻关项目——蔬菜新品种选育研究Ⅳ.甜(辣)椒专题育成的新品种(系)简介

本文介绍了1986-1990年甜(辣)椒专题8个单位育成的15个甜椒、半辛辣椒新品种(系),其抗病性、品质、产量均优于对照品种,并已通过了农业部主持的专家组验收。     

副猪嗜血杆菌病的诊治

近几年频繁发生以多发性浆膜炎、关节炎、脑膜炎以及急性死亡为特征的传染病,导致猪场经济损失严重。本文就该病的病原史、流行特征、临床表现、诊断方法和综合防控等几方面加以分析,希望能对该病的防治起到一定的作用。     

纤维素降解细菌的筛选及其酶活测定

为了充分利用植物废渣中丰富的纤维素资源,以羧甲基纤维素钠(CMC-Na)为唯一碳源的培养基和刚果红染色筛选法从朽木周围富含腐殖质的土壤中筛选得到3株活性较高的纤维素降解细菌：ZWY-3、DP-6和DP-8,并分别在不同的培养时间、培养温度、起始pH、碳源下对3株菌株进行酶活测定。结果表明：3株菌株都在接种后24 h、pH 7、30℃、葡萄糖为碳源时达到产酶高峰,其中接种后24 h时DP-6的酶活最高,达144.86 U;ZWY-3在30℃、pH 7时酶活最大,分别达126.74 U和133.82 U;3株菌株在其最适条件下培养,并以葡萄糖为碳源时,DP-6活性最高,可达218.96 U。3株细菌菌株在降解农业纤维工业中具有良好的应用前景。