体液蛋白质组学的研究和应用

蛋白质组学是目前生命科学的研究热点之一.体液中的蛋白质是来源于与其密切接触组织或者细胞的分泌或渗漏,体液蛋白质组的变化能反映这些组织的生理或者病理改变,因此以寻找疾病相关生物标记为主要目标的比较蛋白质组学是蛋白质组学研究的核心内容之一.对近年来各种体液蛋白质组学的研究状况和应用及存在挑战作一综述.     

茉莉酸类与植物地下贮藏器官的形成

茉莉酸类化合物(茉莉酸及其衍生物)可能参与了马铃薯、薯蓣、菊芋的块茎,甘薯的块根以及洋葱、大蒜的鳞茎形成。JA及MeJA均可诱导离体条件下马铃薯块茎的形成和马铃薯髓部细胞的膨大。JA诱导细胞膨大是由于蔗糖积累导致渗透压增加以及细胞壁结构变化,从而使其伸展性增加,纤维素的合成起了重要作用,细胞骨架也是JA诱导细胞膨大所必需的。但迄今为止,尚未确定块茎形成的直接诱导物。     

A Passive Anti-icing Strategy Based on a Superhydrophobic Mesh with Extremely Low Ice Adhesion Strength

Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.     

The anti-fibrotic effect of betulinic acid is mediated through the inhibition of NF-κB nuclear protein translocation

The purpose of the study was to investigate the anti-fibrotic effect and the potential mechanisms of action of betulinic acid (BA) against hepatic fibrosis in vivo and in vitro. BA is an active compound isolated from the bark of the birch tree Betula spp. (Betulaceae). Liver fibrosis was induced by intraperitoneal injections of thioacetamide (TAA, 200mg/kg) twice weekly for 6weeks in Wistar rats. The administration of BA (20 or 50mg/kg) was started following TAA injections and was continued for 6 or 8weeks to evaluate both the preventive and the protective effects. BA demonstrated great efficacy in preventing and curing hepatic fibrosis via attenuating the TAA-mediated increases in liver tissue hydroxyproline and α-smooth muscle actin (α-SMA). In vitro, BA effectively decreased the HSC-T6 cell viability induced by TNF-α and showed low toxicity in normal human chang liver cells. Moreover, BA significantly attenuated the expression of α-SMA and tissue inhibitor of metalloproteinase-1 (TIMP-1) and increased the levels of matrix metalloprotease (MMP)-13. BA also inhibited the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and the activation of nuclear factor-κB (NF-κB) in a time-dependent manner. This study provides evidence that BA exerts a significant anti-fibrosis effect by modulating the TLR4/MyD88/NF-κB signaling pathway.     

Is There Division of Labor in Cooperative Pseudoscorpions? An Analysis of the Behavioral Repertoire of a Tropical Species

Division of labor is a strategy that maximizes the foraging and reproductive success of eusocial insects. Although some arachnids exhibit colony structure and social organization similar to that of hymenopterans, temporal polyethism has only been demonstrated in few species. The social organization of cooperative pseudoscorpions Paratemnoides nidificator is similar to that of social spiders, but it involves a clear division of labor. Work allocation was experimentally investigated in colonies composed of only one developmental stage (young or adults) or by one sex (males or females), through laboratory manipulation. During 44 h of observation, more than 14 000 behavioral repetitions were quantified, distributed in 95 different types of behavioral acts, and grouped in 10 behavioral categories. The results showed that reproductive colonies of P. nidificator are maintained by gender‐ and age‐based activities. Males and non‐reproductive females performed the external cleaning of the colony and prey capture. Reproductive females take care of the juveniles and build reproductive silk chambers. Nymphs build most of the molt chambers and perform internal cleaning. In the absence of nymphs, male colonies survived 1–2 mo, while female colonies survived 3–4 mo. In nymph colonies, work is readjusted so that all maintenance tasks are executed. This is the first study clearly demonstrating division of tasks in arachnids. It suggests that specialization is an adaptative and evolutionarily old trait in this species. Unlike cooperative spiders, P. nidificator possesses physiological (e.g. reproduction, ecdysis, lifespan) and behavioral (e.g. behavioral synchrony or self‐organization) characteristics that allow task specialization.     

Length–weight relationships of 26 fish species from the middle section of the Negro River (Tacuarembó‐Durazno,Uruguay)

This study provides data on the length–weight relationship (LWR) for 26 species of neotropical fishes. Specimens were collected between 2008 and 2009 from a dam‐enclosed section of the middle Negro River (Uruguay). This study represents the first reference on length–weight relationships for 17 species, and also provides new maximum sizes for eight species.     

Prevalence of potentially pathogenic culturable bacteria on eggshells and in cloacae of female Pied Flycatchers in a temperate habitat in central Spain

ABSTRACT Bacteria grow on avian eggshells and thus can potentially cause diseases in developing embryos. Little is known about culturable bacteria colonizing avian eggshells in free‐living birds, with most studies restricted to poultry. Our objective was to examine the culturable bacterial array growing on eggshells during incubation that could negatively affect hatching success of Pied Flycatchers (Ficedula hypoleuca) in a temperate montane habitat in central Spain. Cloacal culturable bacteria of females were also analyzed because bacteria can be vertically transmitted from females to eggs. We used fecal samples as surrogates of cloacal samples due to the small size of sampled birds. We found that eggshells and female cloacae of Pied Flycatchers harbored 24 and 40 bacterial families and species, respectively, but only a few in each clutch and each cloaca. Rod‐shaped gram‐negative bacteria and bacteria in the family Pseudomonadaceae were the most common bacteria on eggshells during early and late incubation and in female cloacae. Although based on small sample sizes, we found that females with rod‐shaped gram‐negative bacteria in their cloacae laid eggs that also had these bacteria, providing possible evidence for vertical transmission. We found no evidence for vertical transmission of Pseudomonadaceae, suggesting a possible environmental source for these bacteria. The prevalence of bacterial morphological types and major taxonomical categories on eggshells did not vary from early to late stages of incubation, providing support for the hypothesis that incubation may have bacteriostatic effects on bacterial proliferation on eggshells. Despite being primary egg invaders in poultry, we detected no effects of culturable Pseudomonadaceae or Pseudomonas luteola on hatching success. Our study represents the first to examine the culturable bacteria growing on the eggshells of a wild bird in a temperate habitat and additional studies based on culture‐independent techniques are required to confirm our results.