广州大学校园区域供冷分析

对近3年广州大学校园区域供冷系统用冷量数据进行详细的分析,得到区域供冷+板式换热器+二级泵中央空调系统在广东地区高等学校校园建筑应用中的耗冷量、单位面积耗冷量指标、生均耗冷量指标。根据单位面积耗冷量指标,对教学区建筑用冷进行了高低划分,找出了高耗冷量建筑。对区域供冷系统下高校建筑中央空调实际使用中存在的问题进行论述,给出了建议。     

高效液相色谱法分析塑料食品包装材料中的双酚类化合物

双酚类化合物是重要的化工原料之一,广泛用作塑料的增塑剂,但环境中残留的双酚类化合物对人体健康造成威胁,尤其是食品包装材料中的双酚类化合物。采用溶剂提取和高效液相色谱法分析了六种塑料食品包装材料中的四种双酚类化合物,结果表明:有两种样品中检出双酚A,含量分别为106.3μg/g和173.3μg/g,六种样品的加标回收率在77.30%~119.99%之间,相对标准偏差在0.30%~4.4%之间。     

茶叶中提取咖啡因实验分析与改进

实验中采用蒸馏后增加过滤步骤,去除易燃有机物;通过焙炒后加无水乙醇,再加入过量氧化钙,除尽水分;以蒸馏装置代替蒸发皿与倒置漏斗组合装置进行升华,通畅升华气流与避免气态咖啡因溢出。结果表明:实验改进措施有利于茶叶中咖啡因的提取。     

适用于无线体域网的动态口令认证协议

无线体域网中传输的是与生命高度相关的敏感数据，身份认证是信息安全保护的第一道防线。现有的基于人体生物信息的身份认证方案存在信息难提取、偶然性大和误差性大的问题，基于传统密码学的认证方案需较大计算资源和能量消耗，并不适用于无线体域网环境。为此，在动态口令和非对称加密机制基础上，提出一种适用于无线体域网的动态口令双向认证轻量协议，并对其进行形式化分析。通过理论证明、SVO逻辑推理及SPIN模型检测得出：该协议满足双向认证，且能够抵御重放攻击、伪装攻击、拒绝服务器攻击和口令离线攻击，具有较高安全性。     

An integrated bioinformatics analysis and experimental study identified key biomarkers CD300A or CXCL1, pathways and immune infiltration in diabetic nephropathy mice

Diabetic nephropathy (DN) is a common microvascular complication that easily leads to end-stage renal disease. It is important to explore the key biomarkers and molecular mechanisms relevant to diabetic nephropathy (DN). We used highthroughput RNA sequencing to obtain the genes related to DN glomerular tissues and healthy glomerular tissues of mice. Then we used LIMMA to analyze differentially expressed genes (DEGs) between DN and non-diabetic glomerular samples. And we performed KEGG, gene ontology functional (GO) enrichment, and gene set enrichment analysis to reveal the signaling pathway of the disease. The CIBERSORT algorithm based on support vector machine was used to determine the immune infiltration score. Random forest algorithm and Cytoscape obtained hub genes. Finally, we applied co-staining, immunohistochemical staining, RT-qPCR and western blotting to validate the protein and mRNA expression of both hub genes. We obtained 913 DEGs mainly related to inflammatory factors and immunity. GSEA results showed that differential genes were mainly enriched in IL-17 signaling pathway, lipid and atherosclerosis, rheumatoid arthritis, TNF signaling pathway, neutrophil extracellular trap formation, Staphylococcus aureus infection and other pathways. The intersection of the random forest algorithm and Cytoscape revealed both hub genes of CD300A and CXCL1. Experiments have shown that the both key genes of CD300A and CXCL1 shown increased expression in glomerular podocytes, and are related to the inflammation of diabetic nephropathy. And immunohistochemical staining and RT-qPCR further confirmed that the protein and mRNA expression level of CD300A or CXCL1 in glomeruli tissue in DN mice were increased. The expression levels of CD300A and CXCL1 increased significantly under HG (high glucose) stimulation, further confirming that diabetes can lead to increased levels of CD300A and CXCL1 at the cellular level. Through bioinformatics analysis, machine learning algorithms, and experimental research, CD300A and CXCL1 are confirmed as both potential biomarkers in diabetic nephropathy. And we further revealed the main pathways of differential genes and the differentially distributed immune infiltrating cells in diabetic nephropathy.     

The Potential Toxic Side Effects of Flavonoids

Flavonoids are a class of phytochemical molecules abundant in many plants, fruits, vegetables, and leaves. Flavonoids possess a series of significant biological activities, including anticancer, antioxidant, antiviral, and antiinflammatory properties. They become an important source of dietary supplements and natural health products. Though many studies confirmed the safety of flavonoids, the potential toxicity of flavonoids is still a remarkable field of research to be explored. The enthusiasm for flavonoids expressed by the public has sometimes overlooked their toxicity and also consumed the flavonoids exceeding the body requirements. The current review focused on the potential toxicity of flavonoids to make the public consume flavonoids with caution. This review summarizes the current toxicity which has been reported in vivo and in vitro experiments. The toxicity involves carcinogenicity and mutation, liver and kidney toxicity, and the influence on the thyroid and reproductive function and intestinal flora disorders. The mechanism of toxicity is fully complicated, and current evidence indicates that natural flavonoid glycosides act on different targets with different doses in vivo and in vitro experiments. Though most kinds of flavonoids are considered safe, flavonoids proposed as food supplements need to be assessed their tolerable upper intake level as there have been reports of toxic flavonoids.     

基于常规测井资料的煤储层综合评价技术研究

煤储层具有很强的非均质性,准确地把握煤岩特征对后期的开发至关重要。基于鄂尔多斯盆地韩城地区常规测井资料,结合煤岩岩芯测试资料,在对煤岩工业组分定量评价的基础上,运用线性回归法建立经验公式以及相应的测井解释方程,对煤岩的显微组分、工业组分、含气量等进行了定量计算。     

基于有限差分法的泵站底板三维地基应力分析

利用有限差分法，对某泵站不规则底板的地基应力进行计算分析，并结合实测数据，得出在不同本构模型及接触情况下地基应力分布规律。     

基于羧酸型扩链剂超支化水性聚氨酯的合成和表征

以二乙醇胺(DEA)和丁二酸酐为原料,甲醇为溶剂,合成一种新型羧酸型亲水单体N,N-二羟乙基-2-氨基丙酸(DMCA),优化得到DMCA的最佳条件为:冰水浴0℃,n(DEA)∶n(丁二酸酐)为1∶1.2,时间为80 min,甲醇用量为300 m L/mol(DEA),在最佳条件下DMCA的转化率为86.18%。采用红外(FTIR)、核磁(1H NMR)、X射线衍射(XRD)、热重(TG)、元素分析等手段对DMCA进行结构和性能的表征。以DMCA作为亲水扩链剂制备超支化水性聚氨酯DMCA-HWPU,其性能检测结果表明,DMCA-HWPU为非结晶性体系,其乳液呈乳白色泛蓝光,无沉淀,乳液稳定性高,并且具有很好的热稳定性。