Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera

Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity.     

浙江龙泉地区珍贵阔叶树种保护培育工作现状及对策

为了促进人与自然和谐相处,保障生态文明建设,应做好森林资源保护培育工作。通过分析浙江龙泉地区珍贵阔叶树种保护培育工作的现状及问题,提出相应的对策,以完善龙泉地区森林资源建设,促进林业可持续发展。     

基于Web电子商务平台的食用菌产品共词聚类算法

针对食用菌产品电子商务平台的数据挖掘问题,采用了共词聚类算法进行主题聚类,在密度聚类算法的基础上,使用了移动非密集单元的处理方法实现了共词聚类。该算法克服了传统聚类算法裁剪造成的精度误差,提高了聚类结果的精确度,应用在电子商务平台的效果良好。     

Exploring tree diversity and stand structure of savanna woodlands in southeastern Sudan

Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots (1000 m² for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height (DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species (Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm² and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.     

Mapping the current and future distributions of Onosma species endemic to Iran

Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic species. In this study, the spatial distribution of five endemic and threatened species belonging to the genus Onosma (including O. asperrima, O. bisotunensis, O. kotschyi, O. platyphylla, and O. straussii) was investigated under present and future climate change scenarios: RCP2.6 (RCP, representative concentration pathway; optimistic scenario) and RCP8.5 (pessimistic scenario) for the years 2050 and 2080 in Iran. Analysis was conducted using the maximum entropy (MaxEnt) model to provide a basis for the protection and conservation of these species. Seven environmental variables including aspect, depth of soil, silt content, slope, annual precipitation, minimum temperature of the coldest month, and annual temperature range were used as main predictors in this study. The model output for the potential habitat suitability of the studied species showed acceptable performance for all species (i.e., the area under the curve (AUC)>0.800). According to the models generated by MaxEnt, the potential current patterns of the species were consistent with the observed areas of distributions. The projected climate maps under optimistic and pessimistic scenarios (RCP2.6 and RCP8.5, respectively) of 2050 and 2080 resulted in reductions and expansions as well as positive range changes for all species in comparison to their current predicted distributions. Among all species, O. bisotunensis showed the most significant and highest increase under the pessimistic scenario of 2050 and 2080. Finally, the results of this study revealed that the studied plant species have shown an acute adaptability to environmental changes. The results can provide useful information to managers to apply appropriate strategies for the management and conservation of these valuable Iranian medicinal and threatened plant species in the future.     

Sulodexide protects against hyperglycemia-induced retinal vascular injury via suppressing NOX4/NLRP3 pathway

AIM To investigate the effect of sulodexide (SDX) on high glucose-induced damage in retinal microvascular endothelial cells. METHODS (1) High-fat diet combined with intraperitoneal injection of streptozocin were used to induce type 2 diabetes mellitus (DM) followed by injection of saline or SDX in C57BL/6J male mice. Retinal microvascular leakage and density, and the protein levels of NLRP3 inflammasome-related proteins, zonula occludens-1 (ZO-1) and NADPH oxidase 4 (NOX4) were measured. (2) Human retinal microvascular endothelial cells (HRMECs) were treated with normal glucose or high glucose with or without SDX, and were further transfected with siRNA to knock down NOX4, or infected by adenovirus to over-express NOX4. The protein levels of ZO-1, VE-cadherin (VE-Cad), NOX4 and NLRP3 inflammasome-related proteins as well as the level of reactive oxygen species (ROS) were detected. RESULTS Treatment with SDX increased the protein level of ZO-1, attenuated retinal leakage and NLRP3 inflammasome activation, and enhanced the density of microvasculature and the number of ganglion cells in diabetic retinas. The protein levels of ZO-1 and VE-Cad were decreased, while the levels of NOX4, NLRP3 inflammasome-related proteins and ROS generation were increased in high glucose-treated HRMECs. Silencing of NOX4 inhibited high glucose-induced increases in NLRP3 inflammasome and ROS generation, and decreases in the protein levels of ZO-1 and VE-Cad. Over-expression of NOX4 significantly increased the levels of NLRP3 inflammasome-related proteins and ROS generation in HRMECs, and reduced the protein levels of ZO-1 and VE-Cad. Treatment with SDX partly reversed NOX4 over-expression-induced changes. CONCLUSION SDX alleviates hyperglycemia-induced retinal microvascular endothelial injury via inhibiting NOX4/ROS/NLRP3 pathways.     

Importance of mitochondrial calcium uniporter in high glucose-induced cardiac myocyte apoptosis

AIM: To investigate the role of mitochondrial calcium uniporter (MCU) in high glucose(HG)-induced apoptosis of cardiac myocytes. METHODS: Cardiac myocytes were exposed to normal glucose (5.5 mmol/L glucose+ 19.5 mmol/L mannitol), HG (25 mmol/L glucose), or HG combined with 5 μmol/L spermine for 72 h. Mitochondrial free Ca²⁺ concentration ([Ca²⁺]_m), MCU at mRNA and protein levels, pyruvate dehydrogenase (PDH) activity, mitochondrial membrane potential (Δψ_m), the levels of ATP and reactive oxygen species (ROS), and apoptosis were determined. RESULTS: The [Ca²⁺]_m, the mRNA and protein levels of MCU, PDH activity, ATP levels, and Δψ_m were reduced (P<0.05), while ROS content and the protein levels of caspase-9 and caspase-3 were increased in HG group (P<0.05). Adding 5 μmol/L spermine returned these parameters toward control levels (P<0.05). Moreover, apoptosis was reduced by adding spermine and HG treatment (P<0.05). CONCLUSION: HG-induced cardiac myocyte apoptosis may be associated with the decreased MCU expression and activity, abnormal mitochondrial Ca²⁺ handling, deviant mitochon-drial respiratory chain, and mitochondrial dysfunction.