植物源抗菌活性成分的研究进展

介绍近年来国内外研究发现的多种已知结构类型及新结构类型的植物源抗菌活性成分。简要归纳了其抗菌活性及其相应的MIC值。同时对构效关系进行了分析。并对其中抗菌活性较强。具有进一步研究开发价值的化合物及结构类型进行了概括。     

Isoflavonoids from Astragalus mongholicus protect PC12 cells from toxicity induced by L-glutamate

lsoflavonoids, formononetin, 9,10-dimethoxypterocarpan 3-O-beta-D-glucoside, ononin, calycosin 7-O-glc and calycosin, were isolated from the roots of Astragalus mongholicus Bunge (Leguminosae). The neuroprotective roles and direct antioxidant effects of these isoflavonoids were investigated by using PC12 cell model and DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Formononetin, ononin and calycosin were found inhibiting glutamate-induced cell injury, with an estimated 50% effective concentration (EC50) of 0.027 microg/ml, 0.047 microg/ml and 0.031 microg/ml, respectively. Pretreatment with them increased the activities of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and prevented the release of lactate dehydrogenase (LDH) in glutamate-injured PC12 cells. On the other hand, calycosin 7-O-glc and calycosin showed more scavenging activity to DPPH radicals than formononetin in the cell-free system. The inconsistency between the neuroprotective capabilities of isoflavonoids and their directly scavenging activity to DPPH radicals indicated that formononetin, ononin and calycosin probably depended on increasing endogenous antioxidant and stabilizing the cells' membrane structures to inhibit the cell damage induced by glutamate.     

Regional anesthesia and acute perioperative pain management in thoracic surgery: a narrative review

Background and ObjectiveThoracic surgery causes significant pain which can negatively affect pulmonary function and increase risk of postoperative complications. Effective analgesia is important to reduce splinting and atelectasis. Systemic opioids and thoracic epidural analgesia (TEA) have been used for decades and are effective at treating acute post-thoracotomy pain, although both have risks and adverse effects. The advancement of thoracoscopic surgery, a focus on multimodal and opioid-sparing analgesics, and the development of ultrasound-guided regional anesthesia techniques have greatly expanded the options for acute pain management after thoracic surgery. Despite the expansion of surgical techniques and analgesic approaches, there is no clear optimal approach to pain management. This review aims to summarize the body of literature regarding systemic and regional anesthetic techniques for thoracic surgery in both thoracotomy and minimally invasive approaches, with a goal of providing a foundation for providers to make individualized decisions for patients depending on surgical approach and patient factors, and to discuss avenues for future research.MethodsWe searched PubMed and Google Scholar databases from inception to May 2021 using the terms “thoracic surgery”, “thoracic surgery AND pain management”, “thoracic surgery AND analgesia”, “thoracic surgery AND regional anesthesia”, “thoracic surgery AND epidural”. We considered articles written in English and available to the reader.Key Content and FindingsThere is a wide variety of strategies for treating acute pain after thoracic surgery, including multimodal opioid and non-opioid systemic analgesics, regional anesthesia including TEA and paravertebral blocks (PVB), and a recent expansion in the use of novel fascial plane blocks especially for thoracoscopy. The body of literature on the effectiveness of different approaches for thoracotomy and thoracoscopy is a rapidly expanding field and area of active debate.ConclusionsThe optimal analgesic approach for thoracic surgery may depend on patient factors, surgical factors, and institutional factors. Although TEA may provide optimal analgesia after thoracotomy, PVB and emerging fascial plane blocks may offer effective alternatives. A tailored approach using multimodal systemic therapies and regional anesthesia is important, and future studies comparing techniques are necessary to further investigate the optimal approach to improve patient outcomes.     

Magnetoacoustic Wave Scattering and Dynamic Stress Concentration around the Elliptical Opening in Exponential-Gradient Piezomagnetic Materials

Based on the theory of magnetoacoustic coupled dynamics, the purpose of this paper is to evaluate the dynamic stress concentration near an elliptical opening in exponential-gradient piezomagnetic materials under the action of antiplane shear waves. By the wave function expansion, the solutions for the acoustic wave fields and magnetic fields can be obtained. Stress analysis is performed by the complex function method and the conformal mapping method, which are used to solve the boundary conditions problem, and is used to express the dynamic stress concentration coefficient (DSCC) theoretically. As cases, numerical results of DSCCs are plotted and discussed with different incident wave numbers and material parameters by numerical simulation. Compared with circular openings, elliptical openings are widely used in material processing techniques and are more difficult to solve. Numerical results show that the dynamic stress concentration coefficient at the elliptical opening is strongly dependent on various parameters, which indicates that the elliptical opening is more likely to cause crack and damage to exponential-gradient piezomagnetic materials.     

Generation of liquid metal double emulsion droplets using gravity-induced microfluidics

Several microfluidic applications are available for liquid metal droplet generation, but the surface oxidation of liquid metal has placed limitations on its application. Multiphase microfluidics makes it possible to protect the inner droplets by producing the structure of double emulsion droplets. Thus, the generation of liquid metal double emulsion droplets has been developed to prevent the surface oxidation of Galinstan. However, the generation using common methods faces considerable challenges due to the gravity effect introduced from the high density of liquid metal, making it difficult for the shell phase to wrap the inner phase. To overcome this obstacle, we introduce an innovative method – a gravity-induced microfluidic device – to creatively generate controllable liquid metal double emulsion droplets, achieved by altering the measurable inclination angle of the plane. It is found that when the inclination angle ranges from 30° to 45°, the device manages to generate liquid metal double emulsion droplets with perfect double sphere-type configuration. Additionally, the core–shell liquid metal hydrogel capsules present potential applications as multifunctional materials for controlled release systems in drug delivery and biomedical applications. By regulating pH or imposing mechanical force, the hydrogel shell can be dissolved to recover the electrical conductivity of Galinstan for applications in flexible electronics, self-healing conductors, elastomer electronic skin, and tumor therapy.

An innovative method – a gravity-induced microfluidic device – to generate liquid metal double emulsion droplets to prevent the formation of an oxide layer on the liquid metal is introduced.     

脂蛋白脂酶活化剂NO-1886抑制糖尿病兔动脉粥样硬化的形成

目的　合成化合物NO 1886 ,一种脂蛋白脂酶活化观察脂蛋白脂酶活化剂是否降低高脂 /高蔗糖饲料诱发的糖尿病新西兰兔的血浆葡萄糖并减轻其动脉粥样硬化。方法　给予高脂 /高蔗糖饲料升高新西兰兔血浆总胆固醇 ,甘油三酯和葡萄糖及降低高密度脂蛋白胆固醇而导致动脉粥样硬化。饲料中加入 1 0 %NO 1886进行治疗观察。分别在 0、4、8、12、16、2 0及 2 4wk从禁食过夜的兔耳静脉抽取血样测定葡萄糖和脂质水平。第 2 4周末 ,处死动物 ,分离主动脉 ,经苏丹Ⅳ染色固定脂质后 ,计算脂纹病变面积。结果　应用NO 1886后 ,实验动物血浆葡萄糖 ,总胆固醇和甘油三酯降低 ,高密度脂蛋白胆固醇增加。对动脉粥样硬化的发展具有抑制作用。结论　NO 1886不仅可改善脂质紊乱 ,而且可降低血浆葡萄糖 ,减轻糖尿病兔动脉粥样硬化     

大鼠肠道菌群对长梗冬青苷体外代谢的影响

摘 要 目的：探究体外孵育的大鼠肠道菌群对长梗冬青苷的代谢转化规律。方法: 将长梗冬青苷与大鼠肠道菌群在厌氧条件下共孵育,分别于0,4,8,12,24,48 h时取样,经乙酸乙酯萃取后采用HPLC法进行定性和定量分析。结果: 在与大鼠肠道菌群共孵育48 h后,90.8%的长梗冬青苷被代谢转化为M₂,M₂与铁冬青酸对照品通过HPLC分析时色谱行为一致,故确定M₂为铁冬青酸。结论:长梗冬青苷可以被体外孵育的大鼠肠道菌群代谢转化为铁冬青酸。     

Investigation of Potential Use of Soybean Protein Isolate–Chinese Bayberry Tannin Extract Cross-Linked Films in Packaging Applications

The possibility of using commercial bayberry tannin (BT) from a Chinese source as a cross-linker and functional additive to develop soybean protein isolate (SPI)-based films was explored in this study by using the solvent casting method. In particular, the impacts of BT loading on the tensile strength, microstructure, thermal stability, water resistance and antioxidant capacity were fully investigated. The results reveal that SPI incorporated with BT yielded a phenolic–protein hybrid whose relevant films exhibited an improvement in tensile strength of around two times greater compared with native SPI as a result of the formed interactions and covalent cross-links, which could be proven using FTIR spectroscopy. The introduction of BT also led to the compact microstructure of SPI–BT films and enhanced the thermal stability, while the water vapor permeability was reduced compared with the control SPI film, especially at high loading content of tannin. Additionally, the use of BT significantly promoted the antioxidant capacity of the SPI-based films according to DPPH radical scavenging assay results. On this basis, Chinese bayberry tannin is considered a promising natural cross-linker and multifunctional additive that can be dedicated to developing protein-derived films with antioxidant activity for food packaging applications.     

吗啡对糖尿病神经病理痛大鼠机械及冷刺激痛敏症状的影响

目的探讨吗啡对糖尿病神经病理痛大鼠机械及冷刺激痛敏症状的影响。方法35只SD雄性大鼠(180～220 g)腹腔注射链脲佐菌素(STZ)制备成糖尿病神经病理痛模型,出现痛敏症状后,随机分为5组,采用von Frey测试针和冷板(5度)法,测量鞘内给予吗啡后不同时间机械缩腿阈值和冷刺激后的抬足次数(次/5min)变化。结果吗啡以剂量依赖方式提高糖尿病神经痛大鼠机械缩腿阈值、降低冷刺激后的抬足次数,给予吗啡后30 min,0.5、1.0、5.0μg剂量吗啡组的机械缩腿阈值明显增高,而冷刺激抬足次数分别为显著下降,分别与用药前和对照组相比,差异有统计学意义(P<0.05)。结论吗啡能显著提高糖尿病神经痛大鼠的机械缩腿阈值,有效减少冷刺激的抬足次数,对神经源性痛具有明显的镇痛作用。     

回顾十年来对秦汉时期辨证方法的研究

现存秦汉时期的医书有:<五十二病方>、<足臂十一脉灸经>、<阴阳十一脉灸经>、<武威汉代医简>、<内经>、<难经>、<神农本草经>、<伤寒杂病论>,这些书中体现的辨证方法,为中医学的发展奠定了坚实的基础.本文通过近十年来对秦汉时期经典著作中辨证方法的研究资料作一整理分析,认为诸多学者已经进行了有益的探索,总结、评价这一历史时期已经出现或建立的诸多种辨证方法,提出了许多可供参考的学术观点,尤其是对<伤寒论杂病论>的研究,资料更是丰富,故有必要对这一时期的医经原著中的辨证方法进行系统整理,梳理出一条较为清晰的、准确阐述这一重要时期辨证方法体系的源流、形成、发展和演变的学术发展史.