横断山地区果蝇三新种(双翅目：果蝇科)

横断山地区果蝇三新种（双翅目：果蝇科）张文霞,梁醒财（北京大学生命科学学院北京１００８７１）（中国科学院昆明动物研究所昆明６５０２２３）’果蝇属果蝇亚属Ｄｒｏｓｏｐｈｉｌａ（Ｄｒｏｓｏｐｈｉｌａ）的ｍｅｌａｎｄｅｒｉ种组由Ｗｈｅｅｌｅｒ１９４９年建立...     

Subcellular Distribution and Chemical Forms of Cadmium in the Medicine Food Homology Plant <i>Platycodon grandiflorum</i> (Jacq.) A.DC.

Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.     

竹节参鲨烯环氧酶基因的克隆与生物信息学分析

根据已报道的植物鲨烯环氧酶(SE)基因特异性引物克隆竹节参SE基因.结果表明,克隆得到竹节参SE全长为1 632 bp,编码539个氨基酸,命名为PjSE.生物信息学分析指出,PjSE基因的氨基酸序列与人参属植物人参、三七、越南人参的同源性依次为99％、98％和98％.推测PjSE基因定位于线粒体(mTP)、叶绿体(cTP)和分泌途径(SP).PjSE基因存在保守结构域FAD结合位点,含4个跨膜结构域和7个motif结构位点.PjSE蛋白二级结构以无规则卷曲(Random coli)和α-螺旋(Alpha helix)为主要结构元件,延伸链(Extended strand)和β转角(Beta turn)分散于整个蛋白质中,百分比依次占40.82％、37.48％、15.77％、5.94％;该蛋白能折叠形成典型的三维结构.     

Microbial metabolism and necromass mediated fertilization effect on soil organic carbon after long-term community incubation in different climates

Understanding the effects of changing climate and long-term human activities on soil organic carbon (SOC) and the mediating roles of microorganisms is critical to maintain soil C stability in agricultural ecosystem. Here, we took samples from a long-term soil transplantation experiment, in which large transects of Mollisol soil in a cold temperate region were translocated to warm temperate and mid-subtropical regions to simulate different climate conditions, with a fertilization treatment on top. This study aimed to understand fertilization effect on SOC and the role of soil microorganisms featured after long-term community incubation in warm climates. After 12 years of soil transplantation, fertilization led to less reduction of SOC, in which aromatic C increased and the consumption of O-alkyl C and carbonyl C decreased. Soil live microbes were analyzed using propidium monoazide to remove DNAs from dead cells, and their network modulization explained 60.4% of variations in soil labile C. Single-cell Raman spectroscopy combined with D₂O isotope labeling indicated a higher metabolic activity of live microbes to use easily degradable C after soil transplantation. Compared with non-fertilization, there was a significant decrease in soil α- and β-glucosidase and delay on microbial growth with fertilization in warmer climate. Moreover, fertilization significantly increased microbial necromass as indicated by amino sugar content, and its contribution to soil resistant C reached 22.3%. This study evidentially highlights the substantial contribution of soil microbial metabolism and necromass to refractory C of SOC with addition of nutrients in the long-term.Subject terms: Microbial ecology, Biodiversity     

Structural characterization of proteins using residue environments

A primary challenge for structural genomics is the automated functional characterization of protein structures. We have developed a sequence-independent method called S-BLEST (Structure-Based Local Environment Search Tool) for the annotation of previously uncharacterized protein structures. S-BLEST encodes the local environment of an amino acid as a vector of structural property values. It has been applied to all amino acids in a nonredundant database of protein structures to generate a searchable structural resource. Given a query amino acid from an experimentally determined or modeled structure, S-BLEST quickly identifies similar amino acid environments using a K-nearest neighbor search. In addition, the method gives an estimation of the statistical significance of each result. We validated S-BLEST on X-ray crystal structures from the ASTRAL 40 nonredundant dataset. We then applied it to 86 crystallographically determined proteins in the protein data bank (PDB) with unknown function and with no significant sequence neighbors in the PDB. S-BLEST was able to associate 20 proteins with at least one local structural neighbor and identify the amino acid environments that are most similar between those neighbors.     

Performance of a biotrickling filter in the removal of waste gases containing low concentrations of mixed VOCs from a paint and coating plant

The performance of a field-scale biotrickling filter (BTF) in the removal of waste gases containing low concentrations of mixed volatile organic compounds was evaluated. Results showed that acetone and methyl ethyl ketone (MEK) were more easily removed than toluene and styrene. The removal efficiency for acetone and MEK reached over 99% on days 28 and 25 of the operation, whereas those for toluene and styrene were 80 and 63% on day 38. The maximum individual elimination capacities for styrene, toluene, acetone, and MEK were 10.2, 2.7, 4.7, and 8.4 g/m³ h, respectively. These values were achieved at inlet loading rates of 13.9, 3.3, 4.8, and 8.5 g/m³ h, respectively, at an empty bed retention time of 14 s. the removal efficiency for styrene and toluene rapidly increased from 67% and 83% to 86% and over 99%, respectively, when the concentration of ammonia nitrogen (N–NH₄ ⁺) and phosphates (P) in the nutrients increased from 350 to 840 mg/l and 76 to 186 mg/l. When the BTF was restarted after a four-day shutdown, the removal efficiency for toluene was restored to over 99% within a week. However, that for styrene was not restored to its previous level before the shutdown. No noticeable adverse effect on acetone and MEK removal was observed. Denaturing gradient gel electrophoresis results for the bacterial community in the BTF during VOC removal showed that proteobacterial phylum was dominant, and the changes of nutrient concentration and shutdown periods may have played a role in the community structure differences.     

Adenosine A3 receptor stimulation reduces muscle injury following physical trauma and is associated with alterations in the MMP/TIMP response

We have previously demonstrated that in response to traumatic injury in skeletal muscle, there is a dysregulation of the matrix metalloproteases (MMPs) and their inhibitors (TIMPs), a response hypothesized to interfere with proper skeletal muscle regeneration. Moreover, we have shown that pharmacological activation of the adenosine A(3) receptor by Cl-IBMECA in skeletal muscle can protect against ischemia-reperfusion and eccentric exercise injury. However, the mechanism by which Cl-IBMECA protects muscle tissue is poorly defined. This study evaluated the effects of Cl-IBMECA on MMP/TIMP expression in skeletal muscle and tested the hypothesis that adenosine A(3) receptor-stimulated protection of skeletal muscle following traumatic injury is associated with a blunting of MMPs involved in inflammatory processes and collagen degradation, and an increase in MMPs associated with extracellular matrix remodeling. Sixty C57BL/6J male mice were injected with Cl-IBMECA (n = 30) or a vehicle (n = 30), and Evans blue dye. Injury was induced by applying a cold steel probe (-79°C) to the tibialis anterior (TA) muscle for 10 s. TA muscles from uninjured and injured legs were collected 3, 10, and 24 h postinjury for analysis of muscle injury and MMP/TIMP mRNA and protein levels. Twenty-four hours postinjury, 56.8% of the fibers were damaged in vehicle-treated mice vs. 35.4% in Cl-IBMECA-treated mice (P = 0.02). Cl-IBMECA treatment reduced membrane type 1 (MT1)-MMP, MMP-3, MMP-9, and TIMP-1 mRNA expression 2- to 20-fold compared with vehicle-treated mice (P < 0.05). Cl-IBMECA decreased protein levels of latent/shed MT1-MMP 23-2,000%, respectively, 3-10 h postinjury. In Cl-IBMECA-treated mice, latent MMP-2 was decreased 20% 3 h postinjury, active MMP-3 was decreased 64% 3 h postinjury, and latent/active MMP-9 was decreased 417,631% 3 h postinjury and 20% 10 h postinjury. Protein levels of active MMP-2 and latent MMP-3 were increased 25% and 74% 3 h postinjury, respectively. The present study elucidates a new protective role of adenosine A(3) receptor stimulation in posttraumatic skeletal muscle injury.