An experimental semi-active anti-roll system

The use of anti-roll bars to provide additional roll stiffness and therefore to reduce the trade-off between ride and rollover performance has previously been studied. However, little work has been carried out to investigate the benefits of a switchable roll stiffness. Such a semi-active anti-roll system has the ability to have a low roll stiffness during straight-ahead driving for improved ride performance and high roll stiffness during cornering for improved roll performance. Modelling of such a system is conducted and the model is validated against a semi-active anti-roll system fitted to an experimental vehicle. Experimental and theoretical investigations are used to investigate the performance of such a system with several different strategies employed to switch to the high-stiffness state. The use of an air suspension on the vehicle to roll into corners is also investigated, as is the possibility of exploiting the road layout by allowing the vehicle to be in a low-roll-stiffness configuration during a corner, and then to switch to the high-roll-stiffness configuration midcorner, hence 'locking in' a roll angle. The best rollover performance improvement that was achieved was 12.5 per cent. © IMechE 2008.

Stabilization of carbon nanotube field emitters

Carbon nanotubes (CNTs) have been determined to be field emitters of high quality, but CNTs produced by chemical vapour deposition can produce emission currents with high instability and noise. This work finds that adsorbates and amorphous carbon deposited during the growth process are the primary contributors to field emission instability, and shows that burning off the amorphous carbon in air at 450 °C removes the amorphous carbon, resulting in stabilities of better than 3 per cent over 1 h. This work removes one of the major barriers to the use of CNTs in field emission devices.

无指盘臭蛙皮肤活性肽及其基因和在制药中的应用

本发明涉及一种无指盘臭蛙皮肤活性肽及及其基因和在制药中的应用，属于生物医学领域。无指盘臭蛙皮肤活性肽是无指盘臭蛙皮肤活性肽基因编码的一种单链多肽，分子量3015.63道尔顿，等电点10.3，多肽全序列一级结构为： Ala Thr Ala Leu Gly Leu Ser Ser Arg Gly Leu Leu Pro Ile Gly Phe Met Phe Lys Asp Thr Ile Arg Cys Arg Lys Tyr(ATALGLSSRGLLPIGFMFKDTIRCRKY)。编码无指盘臭蛙皮肤活性肽的基因由312个核苷酸组成，其中编码成熟无指盘臭蛙皮肤活性肽为第141-222位核苷酸。人工合成的无指盘臭蛙皮肤活性肽具有很强的抑制细菌和真菌生长的作用，可以作为制备病原微生物感染疾病的治疗药物被应用。无指盘臭蛙皮肤活性肽具有结构简单、人工合成方便、抗菌谱系广、抗菌活性强的特点。

Gel time studies in activation of polyester resins

Gelling times of polyester resins with varying quantities of catalyst and accelerator were studied and the results reported in this communication.

南极隐兆线粒体CO II基因序列及无翅类昆虫分子进化

测定了采自南极隐兆（Cryptopygus nanjiensis）的线粒体细胞色素氧化酶亚基II（CO II）基因序列，并测定了拉提疣兆（Neanura latior）、梅坞格蚖（Gracilentulus maijiawensis）和韦氏鳞八（Lepidocampa weberi）的CO II基因序列，对序列的A + T含量、核苷酸取代和转换/颠换（TS/TV）频率进行了统计分析。计算了种间Tamura-Nei遗传距离，以甲壳类无甲目（Anostraca）的一种卤虫Artemia franciscana作为外群构建了分子系统树。对无翅类昆虫线粒体CO II基因序列A + T含量的进化倾向性、类群间的遗传分歧和系统进化关系进行了探讨。

Sequence variation and genetic diversity in the giant panda

About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottle-neck attacks. Afterwards, its genetic diversity seemed to recover to same extent.

Phylogenetic relationships of Drosophila melanogaster species group deduced from spacer regions of histone gene H2A-H2B

Nucleotide sequences of the spacer region of the histone gene H2A-H2B from 36 species of Drosophila melanogaster species group were determined. The phylogenetic trees were reconstructed with maximum parsimony, maximum likelihood, and Bayesian methods by u

Genomic organization and sequence analysis of the vomeronasal receptor V2R genes in mouse genome

Two multigene superfamilies, named V1R and V2R, encoding seven-transmembrane-domain G-protein coupled receptors (GPCRs) have been identified as pheromone receptors in mammals. Three V2R gene families have been described in mouse and rat. Here we screened

Structural analysis of human CCR2b and primate CCR2b by molecular modeling and molecular dynamics simulation

CCR2b, a chemokine receptor for MCP-1, -2, -3, -4, plays an important role in a variety of diseases involving infection, inflammation, and/or injury, as well as being a coreceptor for HIV-1 infection. Two models of human CCR2b (hCCR2b) were generated by h

半乳糖神经酰胺脂质体对HIV-1感染性的影响

目的研究体外空白及包封抗HIV药物和PFA的GalCer脂质体对HIV-1复制的影响。方法通过HIV p24抗原测定、合胞体抑制实验、融合阻断实验和对HIV感染细胞的保护作用实验等，观察了空白GalCer脂质体、AZT-GalCer脂质体和PFA-GalCer脂质体对HIV-1复制的影响。结果空白GalCer脂质体预处理细胞，能促进HIV-1感染CD4＋细胞；空白GalCer脂质体预处理HIV-1，则抑制了病毒吸附和结合宿主细胞；GalCer脂质体还具有阻断HIV-1感染细胞与正常CD4＋细胞间的融合作用；GalCer脂质体包封AZT或PFA不能显著提高药物体外抗HIV-1活性。结论空白GalCer脂质体预处理细胞，能促进HIV-1感染性；预处理HIV-1，则抑制了病毒的感染。

中国兽类资源数据库管理信息系统的建立与应用

阐明了建立兽类资源管理系统的意义, 然后详细介绍系统的设计目标、数据结构及系统软件的设计。介绍了标本、物种分布名录及文献库管理的功能, 并对该系统创建及应用的物种、地名代码体系作了介绍。最后介绍了已经用此系统建立的昆明动物研究所兽类标本及中国兽类分布名录等基础数据库的概况。

Histology and hormonal effect of Ghrelin on ovary of Benni (Barbus sharpeyi) in order to study sexual maturity, zygote and larval generation

Benni (Barbus sharpeyi) is valuable fish that Khuzastan fisheries office propagated it artificially in Susangerd Fish Propagation Center every year. Pituitary gland is used for this aim but female fish lost their fertilization power after 2-3 years, so in present research, new hormone, that is called Ghrelin. The aims of this research are histology, hormonal, zygote and larval generation studies and comparing the results with each other. Ghrelin is a multifunctional peptidyl hormone which increases GTH-II in fish, amphibian, and birds and mammalian so its effect on Benni sexual maturation was studied. Human Ghrelin (hGRL) was obtained from ANASPEC, Canada, with 28 amino acids. In the present study, three levels of ghrelin including 0 (sham treatments), 0.10 (treatment 1) and 0.15 μg/g (treatment 2) body wt and one level of pituitary gland 4000 μg/g (pituitary treatment) with two replications were used. 56 specimens were injected intraperitonealy and their ghrelin level was evaluated immediately after injection and after 24 h. Control fish(n=16) were just injected by physiological saline. For hormonal studies sham and experimental fish(n=40) were anesthetized with MS-222 at a concentration of 250 mg l-1, and blood samples were collected and kept at 4ْC, then spun to collect serum. Serum samples were stores at -20ْC until the RIA for CTH-II. For histology studies immediately after injection a piece of ovary was collected from control fish (Sham zero) after being anesthetized. The sampled ovaries were fixed in Buin solution and embedded in paraffin, and stained to Sections of 5–6 μm using haematoxylin and eosin. The ovarian samples were performed with a compound microscope. Histology and micrometry studies had done. The mature oocytes had given from mature fish, then weighted and the working fecundity were counted. The mature oocytes fertilized, the eggs were incubated and the percentage of fertilization was calculated. After 72h the eggs hatched and the percentage of hatch was counted. The percentage of hindrance was calculated after 6 days. Hormonal results indicate that ghrelin and pituitary increase significantly the GTH-II level in comparison to sham. Macroscopic observations (before taking ovary) showed that ovaries with green colored have couple oval structure located in the abdominal cavity. Microscopic studies of dissected ovaries indicated simultaneous growth of 127 oocytes with 6 stages. The type of the ovary is asynchronous. The results indicated that both of the ghrelin treatment increased the percentage of mature follicles followed by decrease of immature follicles. There were significant differences (P<0.05) between the number of mature and immature follicles. Average diameter of follicle in both of the ghrelin treatment was significantly (P<0.05) declined in the stages of the vitellogenesis when the result compared to the other treatment. Just treatment 1 and pituitary treatment can give mature oocytes. The fecundity of pituitary treatment significantly increase in comparision to ghrelin treatment (P<0.05). In food-restricted fish where endogenous ghrelin levels are known to be increased, a chronic administration of ghrelin induces overt negative effect in releasing mature oocytes. The percentage of fertilization was significantly increase (P<0.05) in ghrelin t. in comparison to pituitary t. and the percentage of hatch was significantly increase (P<0.05) in pituitary t. in comparison to ghrelin t. There was no significant difference (P>0.05) in terms of percentage of hindrance between treatments. In conclusion, the present study demonstrated that ghrelin has positive effect on the level of GTH-II, oocyte maturation, ovarian vitellogenesis and the number of mature follicles of Barbus sharpeyi ovary. Increasing of the mature follicles number reduces their average diameter, indicating stimulating effect of ghrelin in sexual maturation of Barbus sharpeyi.The ghrelin and pituitary treatment have equal chance in the post-stage of spawning.