刺槐叶的亚显微结构与耐旱性的关系

刺槐（RobiniapseudoacaciaLinn．）虽然引自北美,但现在已成为西北干旱半干旱地区的主要造林树种。叶片形状为羽状复叶,小叶呈椭圆形,叶面积与体积之比为5．6。叶表面具蜡质壳状、管状毛和鳞片状纹饰。叶片与叶柄被以毛状体;叶背面有浅内陷气孔,具大孔下室。上下表皮细胞外壁具明显的角质层加厚;上表皮细胞呈椭圆形,下表皮细胞呈乳头状;栅栏组织与海绵组织之间界限不明显,栅栏组织较为发达,排列紧密,约2—3层细胞,海绵组织有退化的趋势;中脉和叶柄维管束均有厚壁组织细胞组成的维管束鞘;薄壁组织细胞中含有大量的晶体和淀粉粒,叶片已具有许多旱生特征。     

长薄鳅胚胎发育的观察

1999年5月,作者首次通过人工繁殖获得长薄鳅的受精卵,并对其胚胎发育特征进行了连续的观察。卵膜无粘性,吸水后卵周间隙明显膨胀扩大,卵膜径3.67-4.00 mm,平均3.79mm,属漂流性卵。胚胎发育可分为26个时期,初孵仔鱼长5.0mm左右,通体透明无色素。     

鳜鱼人工繁殖的生态生理学特性

在鱖鱼(Siniperca chuatsi)苗种培育过程中,适时投喂适口饵料鱼是成功的关键。要掌握好鳜鱼人工养殖期中的不同水温,催情剂组合与效应时间、胚胎发育时间、胚后內源性营养期之间的关系,才能有效地制订鳜鱼和饵料鱼催产的计划,使鳜鱼苗适时地获得适口饵料。       

Length‐weight relationships for three fishes in the Mali Hka River and Nmai Hka River,Myanmar

Length‐weight relationships (LWRs) were investigated for three fish species occurring in the Mali Hka River and Nmai Hka River. Fish were collected monthly from five sites between January and May 2009, using gill nets in the main river and electrofishing in tributaries (gill nets of three types: (a) = 10 m long, 0.5 m depth, 0.5 cm mesh size); (b) = 15 m long, 1 m depth, 2.0 cm mesh size; and (c) = 20 m long, 1.5 m depth, 6.0 cm mesh size. Soaking time for all was 24 hr). The LWRs for Botia histrionica Blyth, 1860, Crossocheilus burmanicus Hora, 1936 and Schizothorax grahami (Regan, 1904) are given in Table 1 along with the appropriate statistics for the parameters a and b of the equation as well as the confidence intervals and the correlation coefficient. All values of parameter b ranging from 2.57 for Botia histrionica Blyth, 1860 and 3.19 for Crossocheilus burmanicus Hora, 1936 (in all cases r² > 0.96). A new total length has been recorded for Schizothorax grahami (Regan, 1904) when comparing with records given in the international electronic databank FishBase (Froese & Pauly, 2018).     

Electrically Tunable Fiber Optic Sensor Based on Surface Plasmon Resonance

The response of optical fiber surface plasmon resonance (SPR) sensor to potential is monitored in real time. The potential-induced reflectance of a gold-coated optical fiber SPR probe is dependent on potential step width and ionic strength. Wider potential step and stronger ionic strength are generally able to enhance the reflectance and accelerate the response time. The specifically adsorptive anion Cl^? provides a pronounced effect on a potential-dependent SPR probe. The exclusive contact of the SPR probe with anion Cl^? could significantly slow down the optical response. The work offers opportunities for optical fiber SPR probes to characterize the electrochemical application.     

Cyclic Compressive Stress Regulates Apoptosis in Rat Osteoblasts: Involvement of PI3K/Akt and JNK MAPK Signaling Pathways

It is widely accepted that physiological mechanical stimulation suppresses apoptosis and induces synthesis of extracellular matrix by osteoblasts; however, the effect of stress overloading on osteoblasts has not been fully illustrated. In the present study, we investigated the effect of cyclic compressive stress on rat osteoblasts apoptosis, using a novel liquid drop method to generate mechanical stress on osteoblast monolayers. After treatment with different levels of mechanical stress, apoptosis of osteoblasts and activations of mitogen-activated protein kinases (MAPKs) and PI3-kinase (PI3K)/Akt signaling pathways were investigated. Osteoblasts apoptosis was observed after treated with specific inhibitors prior to mechanical stimulation. Protein levels of Bax/Bcl-2/caspase-3 signaling were determined using western blot with or without inhibitors of PI3K/Akt and phosphorylation of c-jun N-terminal kinase (JNK) MAPK. Results showed that mechanical stimulation led to osteoblasts apoptosis in a dose-dependent manner and a remarkable activation of MAPKs and PI3K/Akt signaling pathways. Activation of PI3K/Akt protected against apoptosis, whereas JNK MAPK increased apoptosis via regulation of Bax/Bcl-2/caspase-3 activation. In summary, the PI3K/Akt and JNK MAPK signaling pathways played opposing roles in osteoblasts apoptosis, resulting in inhibition of apoptosis upon small-magnitude stress and increased apoptosis upon large-magnitude stress.     

当归延伸因子AsEF 1β基因的克隆及胁迫应答分析

延伸因子1β(EF 1β)是蛋白质生物合成过程中肽链延长必需的调节因子之一。该研究采用同源克隆和RACE扩增技术克隆当归EF 1β基因序列,分析该基因序列特征、蛋白结构特点及UV B辐射胁迫下的组织响应表达,以揭示当归栽培生境变迁过程中对UV B胁迫适应的分子机制。结果显示：(1)成功克隆获得当归EF 1β基因全长序列(950 bp),编码225个氨基酸,命名为AsEF 1β(GenBank登录号：MG736314);AsEF 1β蛋白的分子量为24.5 kD,理论等电点为4.48,属亲水性氨基酸,在其C末端具有一个EF 1B超蛋白家族的典型结构域和保守区,鸟嘌呤核苷酸交换结构域;其氨基酸序列与同为伞形科的胡萝卜氨基酸序列相似性最高,达93%。(2)qRT PCR分析结果显示,AsEF 1β基因在当归根部的表达量显著高于茎和叶(P<0.05);UV B辐射胁迫下,茎及叶中的表达量均上调,分别是自然光照处理的2.43和3.76倍。研究表明,AsEF 1β基因可能参与当归对UV B辐射胁迫的适应过程,为深入研究其在药用植物生长发育、逆境抗性形成及药效物质的生物合成代谢过程的生态调控奠定了基础。     

枣园昆虫群落及其与日本龟蜡蚧发生的关系

利用群落特征指数和典型相关分析方法,分析了枣园昆虫群落的结构特征以及日本龟蜡蚧发生程度与昆虫群落之间的关系.结果表明,根据群落相异系数(0.20水平),不同样地昆虫群落可划分为平原和丘陵为两类.平原地区日本龟蜡蚧发生程度高,其多样性和物种数较低,而植食性类群优势度较高;丘陵地区日本龟蜡蚧发生程度低,其多样性和物种数较高,而天敌类群优势度较高.典型相关分析表明,在0.05水平下,日本龟蜡蚧发生性状和群落性状的第1对和第2对典型变量相关系数分别为0.9904、0.8538,说明日本龟蜡蚧的发生状况与枣园昆虫群落性状显著相关.其中,群落多样性(3.4893)、物种数(5.8060)和优势度(6.9353)对日本龟蜡蚧的发生程度有重要影响.     

Periploca sepium Bunge as a model plant for rubber biosynthesis study

Periploca sepium Bunge (Chinese silk vine) is a woody climbing vine belonging to the family Asclepiadaceae. It originally comes from Northwest China. Periploca resembles the Para-rubber tree, Hevea brasiliensis, regarding a similar body plan to produce a milky exudate containing rubber latex. The Periploca plant was assessed as a rubber-producing plant by rubber structure elucidation and its molecular weight distribution. A rubber fraction purified from the milky exudate was subjected to 1H NMR analysis, and a characteristic signal derived from cis-polyisoprene was observed. In addition, when the molecular weight distribution of rubber components in the exudate was measured (using size-exclusion chromatography), the number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity (Mw/Mn) were estimated to be Mn = 1.3 x 10(5), Mw = 4.1 x 10(5), and Mw/Mn = 3.1, respectively. Furthermore, the presence of polyisoprene, with Mn = 4.0 x 10(4), Mw = 7.6 x 10(4), and Mw/Mn = 2.5, was also confirmed in plantlets obtained from shoots as a result of tissue culture.     

The Nogo/Nogo Receptor (NgR) Signal Is Involved in Neuroinflammation through the Regulation of Microglial Inflammatory Activation

Microglia have been proposed to play a pivotal role in the inflammation response of the CNS by expressing a range of proinflammatory enzymes and cytokines under pathological stimulus. Our previous study has confirmed that Nogo receptor (NgR), an axon outgrowth inhibition receptor, is also expressed on microglia and regulates cell adhesion and migration behavior in vitro. In the present study, we further investigated the proinflammatory effects and possible mechanisms of Nogo on microglia in vitro. In this study, Nogo peptide, Nogo-P4, a 25-amino acid core inhibitory peptide sequence of Nogo-66, was used. We found that Nogo-P4 was able to induce the expression of inducible nitric-oxide synthase and cyclooxygenase-2 and the release of proinflammatory cytokines, including IL-1β, TNF-α, NO, and prostaglandin E₂ in microglia, which could be reversed by NEP1–40 (Nogo-66(1–40) antagonist peptide), phosphatidylinositol-specificphospholipase C, or NgR siRNA treatment. After Nogo-P4 stimulated microglia, the phosphorylation levels of NF-κB and STAT3 were increased obviously, which further mediated microglia expressing proinflammatory factors induced by Nogo-P4. Taken together, we concluded that Nogo peptide could directly take part in CNS inflammatory process by influencing the expression of proinflammatory factors in microglia, which were related to the NF-κB and STAT3 signal pathways. Besides neurite outgrowth restriction, the Nogo/NgR signal might be involved in multiple processes in various inflammation-associated CNS diseases.