中药糖肾方单体成分莫诺苷药理作用的研究进展

通过查阅近些年的国内外文献对中药糖肾方单体成分莫诺苷的药理作用及分子机制进行归纳、梳理、分析及总结。从分子机制角度阐述莫诺苷具有促进细胞生长、减轻炎性反应、抑制细胞内钙超载、抑制氧化应激、抗凋亡、抗凝等作用,以便为今后临床及实验研究提供更多科学依据。     

牛蒡甙元对老年大鼠肾缺血再灌注损伤的保护作用

目的 探究牛蒡甙元对老年大鼠肾缺血再灌注损伤模型的影响.方法 建立老年大鼠肾缺血再灌注损伤模型,采用随机数字表法将大鼠随机分为6组:假手术组(Sham组)、牛蒡甙元组(ACR组)、肾缺血再灌注模型组(RIRI组)、RIRI+ACR(10 mg/kg)组、RIRI+ACR(20 mg/kg)组和RIRI+ACR(50 m...     

Improved liquid–liquid extraction by modified magnetic nanoparticles for the detection of eight drugs in human blood by HPLC-MS

Magnetic nanoparticles modified with porous titanium dioxide were used as clean-up nanospheres for the detection of eight drug poisons in human blood by high-performance liquid chromatography-mass spectrometry. The magnetic clean-up nanospheres (Fe₃O₄@mTiO₂) with a mesoporous structure were successfully synthesized and characterized by scanning electron microscopy/energy dispersive spectroscopy, transmission electron microscopy, X-ray diffractometry, vibrating sample magnetometry, infrared spectroscopy, and Brunauer–Emmett–Teller techniques. Lipid co-extractives, such as phosphatidic acid and fatty acids, which are major interferences in HPLC-MS analysis causing ion suppression in the MS spectra of blood, could be efficiently removed by Fe₃O₄@mTiO₂ based on the Lewis acid–Lewis base interactions. Following the optimization of the quantities of Fe₃O₄@mTiO₂, the method was applied to the determination of eight drugs in spiked blood. The analytical ranges typically extended from 2 to 500 ng mL⁻¹, and the recoveries ranged from 79.5–99.9% at different concentrations of blood. The limits of quantitation for drug poisons were 0.14–1.03 ng mL⁻¹, which makes the method a viable tool for drug poison monitoring in blood.

High-performance magnetic Fe₃O₄@TiO₂, nanospheres with mesoporous structures was synthesized for cleanup phosphatidic acid and fatty acids in blood sample for 8 drugs test with HPLC-MS.     

Interpenetrating network nanoarchitectonics of antifouling poly(vinylidene fluoride) membranes for oil–water separation

Poly(vinylidene fluoride) (PVDF) membranes are a commonly used cheap material and have been widely used in wastewater treatment. In this study, a simple strategy was proposed to construct PVDF-g-PEG membranes with an interpenetrating network structure by simulating plant roots for the treatment of oil/water emulsion. Meanwhile, the hydrophilicity, antifouling, and mechanical properties of the membrane were improved. A series of chemical and physical characterization methods were used to verify the successful formation of a PVDF-g-PEG layer on the membrane surface. The effects of graft modifier content on the crystallization behavior, microstructure, and membrane permeability were studied. When the optimized membrane (m-PVDF-2) was applied to the treatment of oily wastewater, its separation performance was significantly better than that of the blank PVDF membrane, and the oil removal rate was over 99.3%. BSA and oil contamination were nearly reversible, and excellent oil resistance to high-viscosity oil was also observed. The method reported in this article is a one-step, simple method for constructing hydrophilic and oil-resistant PVDF membranes without any intermediate additives and harmful or costly catalysts. They can be used as an ideal material for preparing efficient oil–water separation membranes.

A simple strategy was proposed to construct PVDF-g-PEG membranes with an interpenetrating network structure.     

Epoxy composite with high thermal conductivity by constructing 3D-oriented carbon fiber and BN network structure

As electronic devices tend to be integrated and high-powered, thermal conductivity is regarded as the crucial parameter of electronic components, which has become the main factor that limits the operating speed and service lifetime of electronic devices. However, constructing continuous thermal conductive paths for low content particle fillers and reducing interface thermal resistance between fillers and matrix are still two challenging issues for the preparation of thermally conductive composites. In this study, 3D-oriented carbon fiber (CF) thermal network structures filled with boron nitride flakes (BN) as thermal conductive bridges were successfully constructed. The epoxy composite was fabricated by thermal conductive material with a 3D oriented structure by the vacuum liquid impregnation method. This special 3D-oriented structure modified by BN (BN/CF) could efficiently broaden the heat conduction pathway and connected adjacent fibers, which leads to the reduction of thermal resistance. The thermal conductivity of the boron nitride/carbon fiber/epoxy resin composite (BN/CF/EP) with 5 vol% 10 mm CF and 40 vol% BN reaches up to 3.1 W m⁻¹ K⁻¹, and its conductivity is only 2.5 × 10⁻⁴ S cm⁻¹. This facile and high-efficient method could provide some useful advice for the thermal management material in the microelectronic field and aerospace industry.

As electronic devices tend to be integrated and high-powered, thermal conductivity is regarded as the crucial parameter of electronic components, which is the main factor that limits the operating speed and service lifetime of electronic devices.     

Surface acidity of tin dioxide nanomaterials revealed with 31P solid-state NMR spectroscopy and DFT calculations

Tin dioxide (SnO₂) nanomaterials are important acid catalysts. It is therefore crucial to obtain details about the surface acidic properties in order to develop structure–property relationships. Herein, we apply ³¹P solid-state NMR spectroscopy combined with a trimethylphosphine (TMP) probe molecule, to study the facet-dependent acidity of SnO₂ nanosheets and nanoshuttles. With the help of density functional theory calculations, we show that the tin cations exposed on the surfaces are Lewis acid sites and their acid strengths rely on surface geometries. As a result, the (001), (101), (110), and (100) facets can be differentiated by the ³¹P NMR shifts of adsorbed TMP molecules, and their fractions in different nanomaterials can be extracted according to deconvoluted ³¹P NMR resonances. The results provide new insights on nanosized oxide acid catalysts.

Facet-dependent acidity of SnO₂ nanosheets and nanoshuttles is revealed with TMP-assisted ³¹P solid-state NMR spectroscopy and DFT calculations.     

A novel multimodal nanoplatform for targeting tumor necrosis

Peri-necrotic tumor regions have been found to be a source of cancer stem cells (CSC), important in tumor recurrence. Necrotic and peri-necrotic tumor zones have poor vascular supply, limiting effective exposure to systemically administered therapeutics. Therefore, there is a critical need to develop agents that can effectively target these relatively protected tumor areas. We have developed a multi-property nanoplatform with necrosis avidity, fluorescence imaging and X-ray tracking capabilities to evaluate its feasibility for therapeutic drug delivery. The developed nanoparticle consists of three elements: poly(ethylene glycol)-block-poly(ε-caprolactone) as the biodegradable carrier; hypericin as a natural compound with fluorescence and necrosis avidity; and gold nanoparticles for X-ray tracking. This reproducible nanoparticle has a hydrodynamic size of 103.9 ± 1.7 nm with a uniform spherical morphology (polydispersity index = 0.12). The nanoparticle shows safety with systemic administration and a stable 30 day profile. Intravenous nanoparticle injection into a subcutaneous tumor-bearing mouse and intra-arterial nanoparticle injection into rabbits bearing VX2 orthotopic liver tumors resulted in fluorescence and X-ray attenuation within the tumors. In addition, ex vivo and histological analysis confirmed the accumulation of hypericin and gold in areas of necrosis and peri-necrosis. This nanoplatform, therefore, has the potential to enhance putative therapeutic drug delivery to necrotic and peri-necrotic areas, and may also have an application for monitoring early response to anti-tumor therapies.

Au-Hyp-NP developed by encapsulation of gold and hypericin into PEG-PCL nanoplatform for fluorescence and X-ray tracking with tumor necrosis targeting.     

Copper(i)-catalyzed radical carboamination reaction of 8-aminoquinoline-oriented buteneamides with chloroform: synthesis of-β-lactams

A novel Cu(CH₃CN)₄PF₆-catalyzed carboamination reaction of 8-aminoquinoline-oriented buteneamides with chloroform to afford 4-(2,2,2-trichloroethyl)-β-lactams is described. The reaction proceeded at 110 °C in air with di-t-butyl peroxide. Preliminary studies indicated that the reaction undergoes a free radical mechanism via a Cu(i)/Cu(ii)/Cu(iii) catalytic cycle.

A novel Cu(CH₃CN)₄PF₆-catalyzed carboamination reaction of 8-aminoquinoline-oriented buteneamides with chloroform to afford 4-(2,2,2-trichloroethyl)-β-lactams is described.     

PD-L1 expression on peripheral T-cells and association with coronary heart disease patients: A protocol for systematic reviews and meta-analysis

Background:As immune checkpoint pathways, programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) can be exploited by tumor cells to evade immuno-surveillance. Inflammation and immune processes play decisive roles in the occurrence and development of coronary heart disease (CHD). The low expression level of PD-1/ PD-L1 or anti-PD-1/PD-L1 therapy can accelerate the immune processes in CHD and aggravates disease based on numerous studies. However, the expression of PD-L1 and CHD still remains controversial to date. We conducted this meta-analysis to detect the value of PD-L1 expression on peripheral T-cells in CHD.Methods:We will search PubMed, Embase, Web of Science, Google Scholar, Chinese National Knowledge Infrastructure, Chinese VIP Information, Wanfang Database, and Chinese Biomedical Literature Database for related published studies before February 2021. Two review authors will search and assess relevant studies independently. Case control studies and cohort studies will be included. The Revman 5.3 software was applied to carry out the meta-analysis for the included literature.Results:The findings of this systematic review will be disseminated in a peer-reviewed publication and/or presented at relevant conferences.Conclusion:This study will provide a new theoretical basis for the immunological prevention and treatment of CHD.Trial registration number:DOI 10.17605/OSF.IO/X3R52.Ethics and dissemination:Formal ethical approval is not required, as the data are not individualized.