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991.
Aurélien Desmarchelier Philipp Feuerrigel Hassan Fathi Ahmed Julie Moulin Andrea Beck Claudia Mujahid 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(4):695-705
A study on stability of veterinary drugs in standard solutions stored at ?80°C and at ?20°C was conducted over 1 year. Data were acquired on 152 individual stock standard solutions and also on 15 family mixes and 2 working standard solutions. All solutions were prepared, stored and compared 1 year later against freshly prepared ones by LC-MS/MS. A statistical analysis was performed to set the acceptability criteria, taking into account the variability of standard preparations. In individual stock standard solutions stored at ?80°C (12 months) and ?20°C (9 months), stability was demonstrated for 141 and 140 out of 152 compounds, i.e. for 92% and 93% of compounds, respectively. Drugs were even more stable when solubilised in either diluted family mixes or working standard solutions, with more than 99% and 94% of compounds found unaltered when stored at ?80°C and at ?20°C, respectively. In mixes, beta-lactams from the cephalosporin (cefadroxil and cephalexin) and penicillin (amoxicillin and ampicillin) families were found to be the least stable compounds when stored at ?20°C (6 months), necessitating storage at ?80°C to achieve a 1-year shelf life. The study also evidenced solubility issues for two sulfonamides (sulfadiazine and sulfamerazine) in methanol-based solutions. An independent stability study conducted by a second laboratory confirmed the 1-year stability of 3 family mixes—quinolones, sulfonamides and tetracyclines. 相似文献
992.
The exploration of molecular recognition of synthetic macrocycles in aqueous media is significantly important since most biological functions, activities and processes take place in water. Pillar[n]arenes (n=5–10) have been recognized as a new generation of macrocyclic arenes; much attention has been devoted to their host-guest chemistry. This review summarizes the host-guest properties of water-soluble pillararenes towards biologically significant molecules and drugs. These water-soluble pillararenes are classified into three major classes according to the electric charges of hydrophilic groups at their portals: anionic pillar[n]arenes ( AP[n]s ), cationic pillar[n]arenes ( CP[n]s ), and neutral pillar[n]arenes ( NP[n]s ). The host–guest affinities, binding modes, binding selectivity, stimuli-responsiveness, as well as biomedical applications are comprehensively discussed. 相似文献
993.
994.
不同温度下超滤对中药含油水体物理化学参数影响的初步研究 总被引：2，自引：0，他引：2
通过考察不同温度下3万相对分子质量的PES膜超滤对中药油水复杂体系物理化学性质的影响,探索中药油水复杂体系在有机膜分离过程中的微观表现。以某中药制药企业采用水蒸气蒸馏工艺所收集的含油水体为实验体系,测定不同温度下膜分离前后各药液的pH值、电导率、盐度、浊度、粘度等指标。研究发现膜分离前后各药液的pH值、电导率、浊度、粘度等表现出不同的变化,温度对物化参数有明显影响。结果表明,3万相对分子质量的PES膜可改变中药油水体系物理化学参数,膜分离技术用于中药的油水分离显示出良好趋势。 相似文献
995.
996.
Hui Wang Kui Wang Bowei Tian Richard Revia Qingxin Mu Mike Jeon Fei‐Chien Chang Miqin Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(46):6388-6397
Applications of hydrophobic drug‐based nanocarriers (NCs) remain largely limited because of their low loading capacity. Here, development of a multifunctional hybrid NC made of a magnetic Fe3O4 core and a mesoporous silica shell embedded with carbon dots (CDs) and paclitaxel (PTX), and covered by another layer of silica is reported. The NC is prepared via a one‐pot process under mild condition. The PTX loading method introduced in this study simplifies drug loading process and demonstrates a high loading capacity due to mesoporous silica dual‐shell structure, supramolecular π‐stacking between conjugated rings of PTX molecules, and aromatic rings of the CDs in the hybrid NC. The CDs serve as both confocal and two‐photon fluorescence imaging probes, while the Fe3O4 core serves as a magnetic resonance imaging contrast agent. Significantly, NC releases PTX in response to near infrared irradiation as a result of local heating of the embedded CDs and the heating of CDs also provides an additional therapeutic effect by thermally killing cancer cells in tumor in addition to the chemotherapeutic effect of released PTX. Both in vitro and in vivo results show that NC demonstrates high therapeutic efficacy through a synergistic effect from the combined chemo‐photothermal treatments. 相似文献
997.
高效液相色谱法测定对虾中五种磺胺类药物残留 总被引：5，自引：1，他引：5
采用反相高效液相色谱法，同时测定对虾中的五种磺胺类药物残留。用C18柱．紫外(或PDA)检测器，流动相为5mmol／L NaH2PO4溶液．乙腈溶液，磷酸调pH2．8，流速1．0mL／min，枉温35℃，于267nm波长处检测。最低检测限达到2μg／kg，相关系数在0．9997以上。五种药残加标回收率在100μg/kg，50μg/kg，10μg/kg三个水平上分别为81．90％，79．86％，71．80％，RSD＜10％亦符合痕量测定要求。 相似文献
998.
Eva Schaller Andi Ma Lisa Chiara Gosch Adrian Klefenz David Schaller Nils Goehringer Leonard Kaps Detlef Schuppan Andrea Volkamer Rainer Schobert Bernhard Biersack Bianca Nitzsche Michael Hpfner 《International journal of molecular sciences》2021,22(5)
New 2-(thien-2-yl)-acrylonitriles with putative kinase inhibitory activity were prepared and tested for their antineoplastic efficacy in hepatoma models. Four out of the 14 derivatives were shown to inhibit hepatoma cell proliferation at (sub-)micromolar concentrations with IC50 values below that of the clinically relevant multikinase inhibitor sorafenib, which served as a reference. Colony formation assays as well as primary in vivo examinations of hepatoma tumors grown on the chorioallantoic membrane of fertilized chicken eggs (CAM assay) confirmed the excellent antineoplastic efficacy of the new derivatives. Their mode of action included an induction of apoptotic capsase-3 activity, while no contribution of unspecific cytotoxic effects was observed in LDH-release measurements. Kinase profiling of cancer relevant protein kinases identified the two 3-aryl-2-(thien-2-yl)acrylonitrile derivatives 1b and 1c as (multi-)kinase inhibitors with a preferential activity against the VEGFR-2 tyrosine kinase. Additional bioinformatic analysis of the VEGFR-2 binding modes by docking and molecular dynamics calculations supported the experimental findings and indicated that the hydroxy group of 1c might be crucial for its distinct inhibitory potency against VEGFR-2. Forthcoming studies will further unveil the underlying mode of action of the promising new derivatives as well as their suitability as an urgently needed novel approach in HCC treatment. 相似文献
999.
1000.
Emilia Marchei Maria Alias Ferri Marta Torrens Magí Farr Roberta Pacifici Simona Pichini Manuela Pellegrini 《International journal of molecular sciences》2021,22(8)
The use of the new psychoactive substances is continuously growing and the implementation of accurate and sensible analysis in biological matrices of users is relevant and fundamental for clinical and forensic purposes. Two different analytical technologies, high-sensitivity gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) were used for a screening analysis of classic drugs and new psychoactive substances and their metabolites in urine of formed heroin addicts under methadone maintenance therapy. Sample preparation involved a liquid-liquid extraction. The UHPLC-HRMS method included Accucore™ phenyl Hexyl (100 × 2.1 mm, 2.6 μm, Thermo, USA) column with a gradient mobile phase consisting of mobile phase A (ammonium formate 2 mM in water, 0.1% formic acid) and mobile phase B (ammonium formate 2 mM in methanol/acetonitrile 50:50 (v/v), 0.1% formic acid) and a full-scan data-dependent MS2 (ddMS2) mode for substances identification (mass range 100–1000 m/z). The GC-MS method employed an ultra-Inert Intuvo GC column (HP-5MS UI, 30 m, 250 µm i.d, film thickness 0.25 µm; Agilent Technologies, Santa Clara, CA, USA) and electron-impact (EI) mass spectra were recorded in total ion monitoring mode (scan range 40–550 m/z). Urine samples from 296 patients with a history of opioid use disorder were examined. Around 80 different psychoactive substances and/or metabolites were identified, being methadone and metabolites the most prevalent ones. The possibility to screen for a huge number of psychotropic substances can be useful in suspected drug related fatalities or acute intoxication/exposure occurring in emergency departments and drug addiction services. 相似文献