反倾岩石边坡变形破坏试验及有限元分析

根据相似理论建立地质力学模型,研究反倾层状边坡岩体的变形破坏机制。介绍了模型试验的设计和过程,研究了原型边坡的变形破坏机制和岩层倾角对边坡稳定性的影响。同时进行了Ansys模拟计算。通过比较这两种研究方法的结果,发现反倾层状边坡岩体的变形机制为倾倒变形,破坏模式为弯折破坏;破坏首先在坡顶产生,边坡变形加速的过程是在开挖结束一段时间后才出现;岩层倾角的变化对反倾边坡的变形影响不敏感,但对边坡变形加速持续时间的长短有较大的影响,岩层倾角越小,变形加速所持续的时间越长。     

Zinc deprivation inhibits extracellular matrix calcification through decreased synthesis of matrix proteins in osteoblasts

Scope: Zinc is implicated as an activator for bone formation, however, its influence on bone calcification has not been reported. This study examined how zinc regulates the bone matrix calcification in osteoblasts. Methods and Results: Two osteoblastic MC3T3‐E1 cell subclones (SC 4 and SC 24 as high and low osteogenic differentiation, respectively) were cultured in normal osteogenic (OSM), Zinc deficient (Zn–, 1 μM), or adequate (Zn+, 15 μM) media up to 20 days. Cells (SC 4) were also supplemented with (50 μg/mL) or no ascorbic acid (AA) in combination with Zinc treatment. Zn– decreased collagen synthesis and matrix accumulation. Although AA is essential for collagen formation, its supplementation could not compensate for Zinc deficiency‐induced detrimental effects on extracellular matrix mineralization. Zn– also decreased the medium and cell layer alkaline phosphatase ALP activity. This decreased ALP activity might cause the decrease of Pi accumulation in response to Zn–, as measured by von Kossa staining. Ca deposition in cell layers, measured by Alizarin red S staining, was also decreased by Zn^–. Conclusion: Our findings suggest that zinc deprivation inhibits extracellular matrix calcification in osteoblasts by decreasing the synthesis and activity of matrix proteins, type I collagen and ALP, and decreasing Ca and Pi accumulation. Therefore zinc deficiency can be considered as risk factor for poor extracellular matrix calcification.     

Curcumin attenuates diabetic nephropathy by inhibiting PKC-α and PKC-β1 activity in streptozotocin-induced type I diabetic rats

Scope : We hypothesized that curcumin, a potent anti‐oxidant, might be beneficial in ameliorating the development of diabetic nephropathy through inhibition of PKC‐α and PKC‐β1 activity‐ERK1/2 pathway. Methods and results : Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) (55 mg/kg) in rats. Three weeks after STZ injection, rats were divided into three groups, namely, normal, diabetic and diabetic treated with curcumin at 100 mg/kg/day, p.o., for 8 wk. At 11 wk after STZ injection, diabetic rats exhibited renal dysfunction, as evidenced by reduced creatinine clearance, increased blood urea nitrogen (BUN) and proteinuria, marked increases in lipid peroxidation, NOX4 and p67phox and decrease in anti‐oxidant enzyme. All of these abnormalities were significantly reversed by curcumin. Furthermore, the high‐glucose‐induced PKC‐α and PKC‐β1 activities and phosphorylated ERK1/2 was significantly diminished by curcumin. Curcumin also attenuated the expression of TGF‐β1, CTGF, osteopontin, p300 and ECM proteins such as fibronectin and type IV collagen. The high‐glucose‐induced expression of VEGF and its receptor VEGF receptor II (flk‐1) was also ameliorated by curcumin. Conclusion : These results prove that curcumin produces dual blockade of both PKC‐α and PKC‐β1 activities, which suggests that curcumin is a potential adjuvant therapy for the prevention and treatment of diabetic nephropathy.     

融汇艺术角度的唐代女装多元化探讨

 唐代服饰风格千姿百态、多彩多姿,服饰文化表现为华丽、开放,唐代服饰上的开放得益于胡、汉文化乃至异域文化之间的交流融合;从融汇艺术的角度全新的诠释唐代服装特点及成因,针对外来文化和内衣外穿的形式分析其款式特点;对唐代融汇胡服特色和多种文化元素的女装进行剖析,唐代服装的融汇艺术形式新颖,拓展了服装融汇艺术的设计域面,对现代服装的设计产生了深远的影响。     

国际食品安全研究的文献计量与可视化分析

自20世纪90年代以来,食品安全问题引起了社会各界的广泛关注。本文运用文献计量学、科学知识图谱理论和知识挖掘方法,对科睿唯安信息服务平台(Web of Science,WoS)核心合集中3024篇食品安全论文及其31032条参考文献进行定量化分析和可视化展示,以探究其研究现状、主题演进和发展趋势。31年间,国际食品安全领域学术论文增加了11倍,研究主阵地为食品科技、农业经济与政策。该领域的知识结构由食源性致病菌、食品安全认知、公共卫生健康、食品安全治理构成;其研究主题呈现出从消费者行为、食源性疾病,到食品安全风险管理、食品安全治理、食品溯源系统、食品检测,再到食品全球价值链、重金属超标、农药残留、食品安全文化,直至区块链技术、新型冠状病毒肺炎(Corona virus disease 2019, COVID-19)、食品欺诈的演化脉络;食品安全知识与溢价支付意愿、食品污染、水海产品安全、蔬菜安全及区块链、新冠肺炎疫情等代表着其前沿趋势,以期为我国在该领域的学术研究和政府监管提供参考借鉴。     

黎锦传承的现状、问题及对策研究

通过调研海南省各市县黎锦技艺传承现状,分析存在的问题,提出新时代黎锦传承人的目标、深化产教融合和借助职业院校发展黎锦等对策,推动黎锦人才培养,促进黎锦的创新发展。     

聚酰亚胺针织物热湿舒适性能研究

针对服用聚酰亚胺在冬季针织产品应用中的热湿舒适性问题,选择聚酰亚胺、棉纤维、黏胶纤维和羊毛单纱合股编织21种纬平针组织织物、四平针组织织物和罗纹空气层组织织物,测试织物结构参数和热湿舒适性能。结果表明,纤维成分、纱线种类和织物组织结构影响织物的保暖性、透湿性、透气性和液态水传递性;基于模糊数学综合评判各织物试样的热湿舒适性能,综合评价值依次为M₁₅>M₁>M₆>M₇>M₈>M₁₃>M₂₀>M₂₁>M₅>M₁₂>M₄>M₁₄>M₃>M₁₉>M₂>M₁₇>M₁₈>M₁₁>M₉