一株耐低温纤维素酶高产菌株的筛选、鉴定和产酶的初步试验

从若尔盖高寒湿地距表层80cm处土壤中筛选出一株纤维素酶高产菌株XW-1。根据形态学、生理生化特征以及16SrDNA核酸序列分析结果表明,该菌属于缺陷短波单胞菌(Brevundimonas sp.)。对该菌产酶条件研究表明,XW-1在含0.5%CMC-Na条件下,20°C培养3d后出现最高酶活,达到15.6U/mL。对其酶学性质初步研究表明,该菌株所产纤维素酶的最适pH为6.0,最适反应温度为20°C,15°C时相对酶活达到80%,并且在5°C时,相对酶活仍能保持56%。     

ER-lysosome lipid transfer protein VPS13C/PARK23 prevents aberrant mtDNA-dependent STING signaling

Mutations in VPS13C cause early-onset, autosomal recessive Parkinson’s disease (PD). We have established that VPS13C encodes a lipid transfer protein localized to contact sites between the ER and late endosomes/lysosomes. In the current study, we demonstrate that depleting VPS13C in HeLa cells causes an accumulation of lysosomes with an altered lipid profile, including an accumulation of di-22:6-BMP, a biomarker of the PD-associated leucine-rich repeat kinase 2 (LRRK2) G2019S mutation. In addition, the DNA-sensing cGAS-STING pathway, which was recently implicated in PD pathogenesis, is activated in these cells. This activation results from a combination of elevated mitochondrial DNA in the cytosol and a defect in the degradation of activated STING, a lysosome-dependent process. These results suggest a link between ER-lysosome lipid transfer and innate immune activation in a model human cell line and place VPS13C in pathways relevant to PD pathogenesis.     

LRG‐1 promotes fat graft survival through the RAB31‐mediated inhibition of hypoxia‐induced apoptosis

Autologous adipose tissue is an ideal soft tissue filling material, and its biocompatibility is better than that of artificial tissue substitutes, foreign bodies and heterogeneous materials. Although autologous fat transplantation has many advantages, the low retention rate of adipose tissue limits its clinical application. Here, we identified a secretory glycoprotein, leucine‐rich‐alpha‐2‐glycoprotein 1 (LRG‐1), that could promote fat graft survival through RAB31‐mediated inhibition of hypoxia‐induced apoptosis. We showed that LRG‐1 injection significantly increased the maintenance of fat volume and weight compared with the control. In addition, higher fat integrity, more viable adipocytes and fewer apoptotic cells were observed in the LRG‐1‐treated groups. Furthermore, we discovered that LRG‐1 could reduce the ADSC apoptosis induced by hypoxic conditions. The mechanism underlying the LRG‐1‐mediated suppression of the ADSC apoptosis induced by hypoxia was mediated by the upregulation of RAB31 expression. Using LRG‐1 for fat grafts may prove to be clinically successful for increasing the retention rate of transplanted fat.     

鄱阳湖浮游甲壳动物群落结构特征

鄱阳湖是中国第一大淡水湖,具有"丰水为湖,枯水为河"的独特特点。为探讨鄱阳湖浮游甲壳动物群落结构及其时空分布的特征,于2009年全年采集其不同季节、不同水位期的浮游甲壳动物样品进行定量分析。结果显示,鄱阳湖浮游甲壳动物群落结构总体与河流浮游甲壳群落具有相似性。无节幼体、象鼻溞、剑水蚤等河流优势类群在鄱阳湖浮游甲壳动物中占优势;而哲水蚤和溞属仅在低水位季节占优势,枝角类丰度仅在高温、高水位、流速缓的季节高过桡足类。丰水期浮游甲壳动物平均丰度和生物量远远高于枯水期,可达枯水期的50倍,差异极其显著(P0.01)。温度和水位变化引起的环境因子改变是导致鄱阳湖浮游甲壳动物发生季节演替的主要原因;而营养盐对浮游甲壳动物的影响并不显著。空间上浮游甲壳动物群落构成明显不同,年均丰度最高和最低的点均出现在河口地区。因此:对于换水周期短,水交换速率快的水体,应该充分考虑水文条件对生物的影响。     

漫湾库区景观破碎化对区域生境质量的影响

水利工程的建设不仅改变了库区的景观格局,还会导致区域生物生境质量的变化。以澜沧江漫湾库区为例,在综合海拔高度、植被类型和水源地距离生境因子的基础上,考虑生物扩散过程,研究了建坝前后整个库区以及典型研究小区(库首、库中、库尾、对照)的重要生境斑块空间分布变化。结果表明:漫湾水电站建成后库区的猕猴总体生境破碎化程度增加,景观连接度减少且重要生境斑块的比例也有所降低,生境质量整体下降;4个研究小区的景观格局变化情况同整个库区相一致。空间上,生境质量明显退化的地区主要分布在库区的西部和南部,尤其是库尾地区,其生境斑块数量相较于建坝前增长了9倍,而景观连接度指数下降了81.48%。回归分析结果表明景观连接度指数与占景观面积百分比指数(PLAND)呈显著正相关(R~2=0.973),与斑块数(NP)呈显著负相关(R~2=-0.611);肯德尔系数表明斑块数(NP)、最大斑块指数(LPI)、占景观百分比指数(PLAND)、相似邻近百分比指数(PLADJ)、连通度指数(CONNECT)和香农多样性指数(SHDI)7个景观格局指数与景观连接度指数均表现出显著一致性。由此看出,库区景观破碎化越严重、区域景观连接度越低生境质量退化越明显;而提高生境主要植被类型的覆盖率、保护连接度贡献大的重要斑块和建设生态廊道,可以有效恢复库区生物生境质量。     

Rhabdomyolysis happened after the start of dabigatran etexilate treatment: A case report

There are few reports of rhabdomyolysis caused by anticoagulants, and it is extremely rare for it to be caused by dabigatran etexilate. An 86-year-old female experienced sudden muscle weakness and pain, a significant increase in Creatine kinase, and renal impairment after oral administration of dabigatran etexilate for 3 weeks. The enhanced thigh MRI showed abnormal signal in multiple thigh muscle groups, indicating that the lesions should be considered inflammatory diseases. In conclusion, the possibility of rhabdomyolysis should be ruled out when muscle weakness and myalgia occur at the beginning of dabigatran etexilate treatment.     

中国增汇型气候保护政策实施对经济的影响

系统地给出了中国实施增汇型CO2减排政策对宏观经济影响的模拟结果,所采用的模拟系统包括基于Pizer,Demeter,Zwaan工作发展的中国气候保护决策支持系统和中国经济可计算一般均衡(CGE)系统。研究结果表明,增汇型气候保护政策较其他单一的气候保护政策更有利于国家经济安全;虽然增汇型气候保护政策在短期内会对国家GDP产出造成影响,但从长远角度看,增汇型气候保护将带动经济的发展,是一项值得推广的减排政策。同时,发现中国实行每年增加4%的碳汇和实施4%能源替代以减少CO2排放控制率,辅助于0.2%的生产型CO2排放控制率,如果能够促进世界其它地区到2050年减排1990年的10%的CO,是一个合适的方案。