不同森林群落结构与光能利用率的关系

本文在人工落叶松纯林及人工落叶松与水典柳混交林的林冠观测数据的基础上建立了落叶松松和水曲柳的树冠锥体模型。通过对上述两种森林群落结构的太阳辐射的观测,利用电磁波的吸收,反射和透射理论分别对以上两种森林群落的光能利用率进行了计算。结果表明理论计算值与实测结果基本一致;双层次混交林的光能利用率高于单层纯林的光能利用率。     

祁连山地区植被特征及其分布规律

分析和讨论了祁连山地区主要植被类型及其分布特征。祁连山地区随着青藏高原的强烈隆升表现为整体抬升,植被具有明显的生态地理边缘效应特征和高原地带性规律。该区植被虽然受到四周的较大影响,但各类高寒植被占有绝对优势,表现出与青藏高原植被整体明显的相似性和广泛的一致性。另一方面,本区植被也有其特殊性及与高原面存在一些差异。因此,建议把祁连山地区做为青藏高原植被区的次一级独立单元     

Separation and Purification of Antioxidant Peptides from Enzymatically Prepared Scorpion (Buthus martensii Karsch) Protein Hydrolysates

International Journal of Peptide Research and Therapeutics - The purpose of this study was to separate and purify antioxidant peptides from the scorpion (Buthus martensii Karsch) protein...     

L‐type voltage‐gated calcium channels in stem cells and tissue engineering

L‐type voltage‐gated calcium ion channels (L‐VGCCs) have been demonstrated to be the mediator of several significant intracellular activities in excitable cells, such as neurons, chromaffin cells and myocytes. Recently, an increasing number of studies have investigated the function of L‐VGCCs in non‐excitable cells, particularly stem cells. However, there appear to be no systematic reviews of the relationship between L‐VGCCs and stem cells, and filling this gap is prescient considering the contribution of L‐VGCCs to the proliferation and differentiation of several types of stem cells. This review will discuss the possible involvement of L‐VGCCs in stem cells, mainly focusing on osteogenesis mediated by mesenchymal stem cells (MSCs) from different tissues and neurogenesis mediated by neural stem/progenitor cells (NSCs). Additionally, advanced applications that use these channels as the target for tissue engineering, which may offer the hope of tissue regeneration in the future, will also be explored.     

The Functional and Molecular Properties,Physiological Functions,and Pathophysiological Roles of GluN2A in the Central Nervous System

The NMDA receptor, which is heavily involved in several human brain diseases, is a heteromeric ligand-gated ion channel that interacts with multiple intracellular proteins through the C-termini of different subunits. GluN2A and GluN2B are the two primary types of GluN2 subunits in the forebrain. During the developmental period, there is a switch from GluN2B- to GluN2A-containing NMDA receptors in synapses. In the adult brain, GluN2A exists at synaptic sites more abundantly than GluN2B. GluN2A plays important roles not only in synaptic plasticity but also in mediating physiological functions, such as learning and memory. GluN2A has also been involved in many common human diseases, such as cerebral ischemia, seizure disorder, Alzheimer’s disease, and systemic lupus erythematosus. The following review investigates the functional and molecular properties, physiological functions, and pathophysiological roles of the GluN2A subunit.     

根据中肠病变程度估计松毛虫CPV产量和采收时机

将感染质型多角体病毒的松毛虫中肠分为四种类型 ,研究各型所占比例与病毒产量间的关系 ,结果显示单位虫重的病毒产量随Ⅰ、Ⅱ类比例的增大而增高 ,Ⅰ、Ⅱ类比例为 2 1% - 80 %时 ,每公斤虫的病毒产量为 5.59× 10 10 PIB - 55.2 1× 10 10 PIB ,适宜的采收时机为Ⅰ、Ⅱ类比例为 60 % -80 %时 ,此时采收 ,每公斤虫可产出质型多角体病毒 37.2 1× 10 10 PIB～ 55.2 1× 10 10 PIB     

不同种源长白落叶松(Larix olgensis)生长的比较研究

通过对柴河林业局头道林场一块8年生的落叶松人工林优势种群的当年生的生长节律与生物量的研究发现:优势林分的当年生枝及顶枝的生长较常规林分高峰期多、高峰期持续时间长和生长量大的优点和不同;生物量的分配的研究结果也说明优势林分的树干生物量积累的比重较常规林分高,证明了该罕见优势林分速生原因的内质性,是一个难得的优良种源。     

抑瘤基因NGX6对鼻咽癌细胞株HNE1细胞生长的影响(英文)

鼻咽癌是我国南方多发恶性肿瘤 ,它的发生发展与遗传因素密切相关 .采用定位候选克隆策略在 9p上克隆出一个候选抑瘤基因 ,命名为NGX6 .为了进一步研究它的功能 ,将NGX6基因的全长cDNA片段亚克隆至pcDNA3.1(+ )的表达载体中 ,通过脂质体转染入鼻咽癌细胞系HNE1中 ,Northern杂交方法筛选高效表达NGX6的细胞株 ,并借助细胞生长曲线、软琼脂糖集落形成实验、裸鼠体内接种实验和流式细胞仪对转染细胞的生物学行为进行了检测 .结果显示 ,转染了NGX6基因的HNE1细胞的生长速度明显减慢 ,在软琼脂中集落形成率较对照组显著下降 (P〈0 0 5 ) ,裸鼠体内成瘤的时间较对照组明显延长 ,瘤体的大小和重量较对照组明显减少 ,流式细胞仪检测发现细胞的凋亡率无明显变化 .为了明确NGX6蛋白在细胞中发挥作用的部位 ,进一步将NGX6的开放阅读框架完整正确地克隆到pEGFPC1的荧光载体中 ,转染到COS7细胞中 ,用荧光显微镜观察细胞中荧光的分布 ,发现荧光主要分布在细胞浆中 ,说明NGX6蛋白可能是一种胞浆蛋白 .该研究表明 ,NGX6在NPC的发生发展中起重要作用 ,为全面阐述NGX6的功能提供重要的信息 ,为进一步的功能研究打下基础