Research strategies for safety evaluation of nanomaterials, Part I: evaluating the human health implications of exposure to nanoscale materials.

Nanotechnology has the potential to dramatically improve the effectiveness of a number of existing consumer and industrial products and could have a substantial impact on the development of new products ranging from disease diagnosis and treatment to environmental remediation. The broad range of possible nanotechnology applications could lead to substantive changes in industrial productivity, economic growth, and international trade. A continuing evaluation of the human health implications of exposure to nanoscale materials will be essential before the commercial benefits of these materials can be fully realized. The purpose of this article is to review the human health implications of exposure to nanoscale materials in the context of a toxicological risk evaluation, the current scope of U.S. Federal research on nanoscale materials, and selected toxicological studies associated with nanoscale materials to note emerging research in this area.     

远志属药用植物有效物质群结构特点及其生理活性

系统综述了远志属药用植物有效物质群三萜皂苷、()酮、寡糖酯类成分的结构特点及研究进展,三者作为该属特征性成分,具有广泛的生理活性,作为药用经济植物,该属植物具有广阔的开发前景.     

中药材野生抚育的理论与实践探讨

中药材野生抚育是野生药材采集与家种药材栽培有机结合的一种新兴药材生产方式。作者结合研究现状探讨了中药材野生抚育的概念、特征。中药材野生抚育的基本方式有封禁、人工管理、人工补种、仿野生栽培等。它是一项系统工程技术 ,是中药资源学、生态学、药用植物栽培学、道地药材学等学科的交叉。中药材野生抚育实现了药材生产与生态环境保护的协调发展 ,可以应用于生长条件要求苛刻或家种后质量改变较大等类型药材。文中最后简要分析了几个中药材野生抚育的成功典范 ,并指出中药材野生抚育开辟了中药材生产的生态产业模式 ,具有很好的发展前景 ,需要更多企业介入 ,需要国家加大基础性研究投入。     

经典名方中玄参的本草考证

通过查阅历代本草、医籍、方书及近现代文献资料，对经典名方中所用饴糖的名称、品种、原料及制作工艺进行了考证，为含有饴糖的经典名方开发利用提供依据。经考证可知，饴糖之名历代多源于其形态、质地、制法、原料及产地。古代所用饴糖根据质地不同，主要分为软、硬两类，湿软如蜜者称为“饴”或“胶饴”，质硬色白的则称为“饧”“糖”，现代则多称为麦芽糖，入药仅用胶饴，饧则多作食用；历代药用胶饴推崇糯米（来源于Oryza sativa var. glutinosa）为原料，以大麦Hordeum vulgare制蘖，经过发酵、煎煮、浓缩制备而成，而粟米（来源于Setaria italica var. germanica）、黍Panicum miliaceum等其他谷物为原料制成的饴糖品质次之。2020年版《中华人民共和国药典》未收录饴糖，收载了药用辅料麦芽糖，为纯度较高的结晶粉；但国家食品标准与地方炮制规范中收录了饴糖。基于考证结果，建议经典名方开发中所用胶饴可参考GB/T 20883—2017中的麦芽糖浆，并明确以糯米、大麦为原料。     

Effect of inflammation on endothelial cells induced by poly-L-lactic acid degradation in vitro and in vivo

Abstract

As a promising candidate, biodegradable Poly-L-lactic Acid (PLLA) has been extensively used in coronary artery stents. In our previous reports, PLLA stents implanted in porcine coronary arteries showed safety without stent thrombosis. However, inflammatory responses were observed, which needed further study. In this study, human aortic endothelial cells (HAEC) were treated with different volume percentages of extract of pre-degraded PLLA (extract of PLLA) in vitro, and the cell growth curve and morphological changes were examined. The expression of inflammatory cytokines such as NF-κB, VEGF and VCAM-1 were also observed by ELISA. In addition, PLLA stent was implanted in porcine coronary artery to examine morphological changes, functional marker eNOS and inflammatory responses. The extract of PLLA caused significant growth inhibition and release of NF-κB, VEGF and VCAM-1 in HAEC with volume percentage-dependence. Although re-endothelialization and expression of eNOS was observed, expression of NF-κB and lymphocytes surrounding PLLA were also found after PLLA stents were implanted in the artery. This study demonstrated the effects of inflammation on endothelial cells induced by PLLA degradation in vitro and showed the inflammation in vivo, suggesting that anti-inflammatory strategy is necessary for PLLA stent implantation in the artery.     

An evaluation of microleakage of various glass ionomer based restorative materials in deciduous and permanent teeth: An in vitro study

AimTo evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth.MethodOne hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope.ResultSignificant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth.ConclusionsGC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage.     

Chitin-based poly(urea-urethane)s

—Chitins of various origins in DMA-LiCl solution have been reacted with excess 1,6-diisocyanatohexane (three or twelve equivalents per repeating unit) for 4-20 h. The resulting solutions were exposed to water vapor for 2 days and flexible and opaque materials were produced, which upon drying yielded powders whose main characteristics were insolubility in aqueous and organic solvents, remarkable crystallinity, typical infrared spectrum, high N/C ratio (0.287), and a high degree of substitution (0.29). Under the SEM structural features reminiscent of chitin were absent but no thermoplastic behavior was found by differential scanning calorimetry. Chitosan was similarly treated under heterogeneous conditions in anhydrous pyridine, and yielded reaction products with a lower degree of substitution (0.17). With partially hydrolysed chitosan, highly crystalline products were obtained.     

Fluoride bioactive glass paste improves bond durability and remineralizes tooth structure prior to adhesive restoration

ObjectiveThe current study aimed at examining a fluoride containing bioactive glass (BiominF®) paste as a temporary filling material capable of remineralizing the demineralized enamel or dentin, and its ability to decrease a simulated dentinal fluids pressure on the resin/dentin interface, without affecting the shear bond strength of a universal bonding agent to enamel and dentin.Methods60 premolars were utilized for the acid resistance, trans-microradiography (TMR) and shear bond strength (SBS) experiments. Enamel and dentin discs were demineralized for 4 days to create a subsurface demineralized zone followed by applying BiominF® paste, 1.23% acidulated phosphate fluoride, or a temporary filling material for 24 h.30 extracted human non-carious third molars were utilized for the pulpal pressure experiment in which direct communication to the pulp chamber was created by cutting at a level approximately 1 mm below the cemento-enamel junction while the coronal enamel was ground to expose mid coronal dentin. The dentin surface was exposed to a simulated pulpal pressure. The dentin surfaces had BiominF® paste, an oxalate desensitizing agent, or temporary filling material followed by application of a universal adhesive system.ResultsOne way ANOVA showed that BiominF® paste remineralized effectively the demineralized enamel or dentin, did not affect the bond strength of the enamel and dentin surfaces to the tested adhesive system p < 0.05, and improved the acid resistance of the demineralized enamel and dentin against a secondary erosive challenge. Moreover, BiominF® paste decreased the nanoleakage expression in the dentin/adhesive interface exposed to a simulated pulpal pressure.SignificanceBiominF® paste may serve as a temporary filling material that may improve the longevity of adhesive restorations and help to conserve tooth structures by preserving the demineralized enamel and dentin form cutting during cavity preparation.     

Counting primary loops in polymer gels

Much of our fundamental knowledge related to polymer networks is built on an assumption of ideal end-linked network structure. Real networks invariably possess topological imperfections that negatively affect mechanical properties; modifications of classical network theories have been developed to account for these defects. Despite decades of effort, there are no known experimental protocols for precise quantification of even the simplest topological network imperfections: primary loops. Here we present a simple conceptual framework that enables primary loop quantification in polymeric materials. We apply this framework to measure the fraction of primary loop junctions in trifunctional PEG-based hydrogels. We anticipate that the concepts described here will open new avenues of theoretical and experimental research related to polymer network structure.     

肿瘤相关性贫血的治疗

肿瘤相关性贫血是肿瘤相关性炎症或肿瘤相关治疗导致骨髓抑制（主要是放、化疗）引起的贫血。肿瘤相关性 贫血可以发生在肿瘤诊治的任何阶段，其发生与肿瘤类型、分期及治疗等因素密切相关。2012 年国内的调查显示，肿瘤相 关性贫血的发生率为60.83%，其中轻度贫血40.84%，中度贫血15.67%，重度贫血3.47%，极重度贫血0.84%。发病率较高的肿瘤分别为消化道癌、乳腺癌和肺癌等。研究显示，肿瘤相关性贫血会明显降低肿瘤患者的生活质量，影响治疗效果， 缩短生存期，增加死亡风险；而通过合理的治疗，纠正贫血后，可以改善患者的生活质量，提高生存率。肿瘤相关性贫血 的发病机制复杂，可能与肿瘤本身及其并发症（如肿瘤侵犯骨髓、溶血、失血、肿瘤相关性炎症等）、治疗手段引起的骨 髓抑制（化疗、放疗等）等有关。肿瘤相关性贫血的治疗目标为“提高生活质量，降低红细胞输注需求”。在病因治疗的 基础上，补充造血原料（铁剂、叶酸、维生素 B12 等），应用促红细胞生成素类药物及输红细胞治疗为其常用治疗手段。