组织器官脱细胞支架的制备及研究进展北大核心CSCD

脱细胞基质(decellularized extracellular matrix, dECM)旨在去除引起免疫排斥的细胞,保留原组织结构和成分。由于其具有与原组织器官相似的结构和成分,在组织工程和生物医学的应用上受到广泛关注,已成为一种很有前景的生物医学材料。通过适当的脱细胞方法,dECM很容易能够从组织器官中获得。文中总结了脱细胞的方法及最新研究进展,同时对脱细胞后支架灭菌、交联和保存的方式进行综述,概括了不同组织器官获得的脱细胞支架的最新应用及进展。最后对脱细胞支架目前面临的问题和挑战进行分析,并展望了未来的发展趋势。     

基于多源遥感数据的农业干旱监测模型构建及应用

干旱监测问题是干旱灾害模拟与预警及旱灾防灾减灾的关键。基于2001-2013年淮河流域40个气象站资料、28个土壤墒情站点和中分辨率成像光谱仪（MODIS）多源遥感数据,采用SEN趋势法和标准化降水蒸散指数（SPEI）等方法,综合了大气-植被-土壤相互作用等多元成因,构建了适用于淮河流域多源综合遥感干旱监测模型,探讨淮河流域干旱时空规律。研究表明：（1）基于多源数据构建综合干旱监测模型,利用土壤墒情和典型年份干旱监测对综合干旱监测模型适用性进行评价,通过了P < 0.01的显著性检验,构建的模型可综合反映出农业和气象干旱多源信息;（2）淮河流域干旱面积和干旱频率大都集中在4-5月和7-9月,9月份受旱面积最大。河南省是淮河流域受旱频率最高,其干旱面积占淮河流域多年平均干旱面积比重最大（38%）,其次是安徽（22%）,旱地受旱面积比重大于水田受旱面积比重;（3）淮河流域2、3和5月干旱有显著减弱趋势;而1、4和6月则有增强趋势。淮河流域小麦灌浆-成熟时期（4-6月）缺水对小麦粮食产量影响显著,综合淮河流域干旱趋势变化,需强化淮河流域4月份小麦的干旱监测与旱灾预警。     

Linking city‐level input–output table to urban energy footprint: Construction framework and application

Multiregion input–output (MRIO) models have become increasingly important in economic and environmental analysis. However, the current resolution of most MRIO models fails to capture the heterogeneity between subregions, especially in cities. The lack of city‐level MRIO tables has impeded the accomplishment of city‐level studies and hampered the understanding of the relationship between urban growth and consumption, and teleconnections to other regions. In this paper, we propose a partial survey‐based multiple‐layer framework for MRIO table compilation of a Chinese province that distinguishes city‐based regions. This framework can effectively address a large number of data processes and retain consistency between layers. Using the framework, we first compile a nested Hebei‐China city‐level MRIO table and then apply city‐level energy footprint accounting of the North China urban agglomeration. Our results present the critical role of Hebei cities in energy supply in 2012 and quantify energy use embodied in goods for the domestic trade. Tangshan, Shijiazhuang, and Handan are distinctive cities in the energy supply chain of other regions, for both less developed and developed regions. This multiple‐layer framework represents a feasible approach for developing subregional‐level MRIO models and offers the possibility to analyze global trade at the subregional level with limited data. The data and results from the analysis in this article are available for download from China Emission Accounts and Datasets.     

Mesenchymal stem cell‐derived exosomes ameliorate erection by reducing oxidative stress damage of corpus cavernosum in a rat model of artery injury

Erectile dysfunction (ED) is a common ageing male's disease, and vascular ED accounts for the largest proportion of all types of ED. One of the mechanisms of vascular ED in the clinic is arterial insufficiency, which mainly caused by atherosclerosis, trauma and surgical. Moreover, oxidative stress damage after tissue ischemia usually aggravated the progress of ED. As a new way of acellular therapy, mesenchymal stem cell‐derived exosomes (MSC‐Exos) have great potential in ED treatment. In the current study, we have explored the mechanism of MSC‐Exos therapy in a rat model of internal iliac artery injury‐induced ED. Compared with intracavernous (IC) injection of phosphate‐buffered saline after artery injury, of note, we observed that both mesenchymal stem cells (MSCs) and MSC‐Exos through IC injection could improve the erectile function to varying degrees. More specifically, IC injection MSC‐Exos could promote cavernous sinus endothelial formation, reduce the organization oxidative stress damage, and improve the nitric oxide synthase and smooth muscle content in the corpus cavernosum. With similar potency compared with the stem cell therapy and other unique advantages, IC injection of MSC‐ Exos could be an effective treatment to ameliorate erectile function in a rat model of arterial injury.     

The densovirus of Periplaneta fuliginosa (PfDNV) as an insect vector for persistent foreign gene expression in vivo

An infectious clone of the Periplaneta fuliginosa densovirus (PfDNV) has been constructed and the PfDNV genome can rescue from the plasmid and replicate as the wild-type virus in nymphs of P. fuliginosa. To investigate the ability of the cloned PfDNV genome to be used as a stable and persistent expression vector, we constructed seven recombinant plasmids in which the GFP reporter gene was inserted into the genome of PfDNV. When these recombinant constructs were transfected into hosts, the GFP was expressed efficiently in every clone. Southern blot analysis revealed that recombinant plasmids had integrated into host genome. Infectious recombinant virions could be produced from plasmids in which the GFP gene was downstream of and in frame with the NS3 and NS1 coding regions. These results indicate that PfDNV genome can be used as an insect vector for the transfer and persistent expression of an exogenous gene.     

Structural differences between <Emphasis Type="Italic">Fusarium</Emphasis> strains investigated by FT-IR spectroscopy

The structural characteristics of Fusarium have received attention from both pure and applied scientists. Because many genes and physiological mechanisms are involved in the development of a particular structure type, this research is complicated. For revealing the structure of macromolecule in these fungal cells, FT-IR spectroscopy combined with multivariate statistical analysis was performed to characterize the structure of protein and polysaccharide of spores and mycelia obtained from different culture medium. The second derivative FT-IR spectra exhibited strain-specific infrared characteristics in the protein secondary structure sensitive amide I region. The region between 750 and 950 cm⁻¹ assigned to α-and β-glucans was investigated for studied samples. Principal components analysis (PCA) allowed us to separate mycelia into two clusters according to different growth medium, indicating that spectra of strains may have been greatly affected by cultivation conditions. Published in Russian in Biokhimiya, 2007, Vol. 72, No. 1, pp. 72–79.     

随机突变文库构建与筛选研究进展

定向进化是一个循环过程,在构建多样化基因序列和筛选功能基因变体之间交替进行.该技术目前已被广泛应用于DNA序列、基因功能和蛋白质结构的优化和分析.定向进化包括随机基因文库的生成、基因在合适宿主中的表达和突变文库的筛选.构建基因文库的关键是库容量和突变多样性,而筛选变体的关键是高灵敏度和高通量.文中讨论了定向进化技术的最...     

重组质粒转染蟑螂对黑胸大蠊浓核病毒的拯救

用Glassmilk法纯化PfDNV dsDNA,在其3′端和PstⅠ切开的pUC119质粒的3′端分别加dG和dC尾,连接、转化、筛选得到分子量为8.7kb的重组质粒.通过酶切证明插入DNA为PfDNV全基因组DNA.利用DEAE-dextran转染技术,将此重组质粒导入黑胸大蠊幼虫体内,此重组质粒能使虫体发病死亡.电镜超薄切片观察发现虫体细胞内存在大量的病毒粒子.同样,在免疫扩散实验中虫体PBS浸出液能与抗PfDNV的抗体产生沉淀线.用重组质粒感染致死的虫体喂食健康黑胸大蠊,也能使其发病死亡,通过电镜可以观察到在细胞内增殖的病毒粒子.