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1.
Ribonucleic acid N6‐methyladenosine methylation plays an important role in a variety of biological processes and diseases. Acetaminophen‐induced hepatotoxicity is one of the major challenges faced by clinicians. To date, the link between N6‐methyladenosine and acetaminophen‐induced hepatotoxicity has not been studied. In this study, a simple ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the simultaneous determination of five nucleosides (adenosine, uridine, cytidine, guanosine, and N6‐methyladenosine) in messenger ribonucleic acid. After enzymatic digestion of messenger ribonucleic acid, the nucleosides sample was separated on an Acquity UPLC column with gradient elution using methanol and 0.02% formic acid water, and detected by a Qtrap 4500 mass spectrometer with an electrospray ionization mode. The method was validated over the concentration ranges of 4–800 ng/mL for adenosine, uridine, cytidine, and guanosine and 0.1–20 ng/mL for N6‐methyladenosine. It was successfully applied to the determination of N6‐methyladenosine levels in liver messenger ribonucleic acid in an acetaminophen‐induced hepatotoxicity mouse model and a control group. This study offers a method for the determination of nucleoside contents in epigenetic studies and constitutes the first step toward the investigation of ribonucleic acid methylation in acetaminophen‐induced hepatotoxicity, which will facilitate the elucidation of its mechanism.  相似文献   
2.
We developed novel stability‐indicating HPLC method for simultaneous estimation of 14 impurities in excedrin tablet, a formulation with a combination of acetaminophen, aspirin, and caffeine. In addition, a new impurity that was generated through degradation of aspirin at high temperatures during the accelerated stability conditions was positively identified and confirmed, using liquid chromatography–mass spectrometry technique. The HPLC method was optimized using the Inertsustain C18, 250 × 4.6 mm, 5.0 μm column, employing simple gradient method. Forced degradation studies were performed under acidic, basic, oxidative and thermal conditions to prove the scope and stability‐indicating the nature of the method. The optimized method was validated as per the International Conference on Harmonization guidelines. The HPLC method showed linearity from LOQ concentration to 21 μg mL?1. Precision and intermediate precision values were <5% RSD. The validated HPLC method is currently applied for the routine testing of excedrin tablet formulations in quality control laboratories.  相似文献   
3.
A novel sensing material, MnFe2O4/polyaniline (PANI), was fabricated by doping PANI to MnFe2O4 on a modified glassy carbon electrode (GCE). This sensing material was characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and high‐resolution transmission electron microscopy (HR‐TEM). Using a cyclic voltammetry electrochemical‐sensing method, we tested MnFe2O4/PANI, and an acetaminophen concentration of 0.0625–5 mM was recorded. Furthermore, the sensor responses were 2.05–22.44. The detection limit was 2.23 × 10?7 M. Strong selectivity was observed for MnFe2O4/PANI, which is a possible sensing mechanism.  相似文献   
4.
《Electroanalysis》2017,29(6):1524-1531
Simultaneous sensing of dopamine (DA), acetaminophen (AP) and melatonin (MEL) was made by electrochemical method as the drugs melatonin and acetaminophen interact with dopamine in brain to induce neuro disorders. The glassy carbon electrode surface was modified with un‐doped α‐ Fe2O3, platinum doped Fe2O3 (dPtFe2O3), Pt decorated Fe2O3 (sPtFe2O3) and doped and decorated Fe2O3 (sdPtFe2O3) nano particles that are synthesized by co‐precipitation method in presence of polyethylene glycol for the first time. These particles were characterized using Ultra‐Violet Visible (UV‐Vis), scanning electron microscopy (SEM), X‐ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA) and electrochemical techniques. The sdPtFe2O3 showed the highest catalytic activity than the dPtFe2O3, sPtFe2O3 and un‐doped α‐ Fe2O3 with well separated voltammetric peaks for DA and AP in presence of MEL. This is attributed to higher surface hydration effects of the sdPtFe2O3, dPtFe2O3 and sPtFe2O3 than the un‐doped Fe2O3 which plays a vital role in enhancing the melatonin sensing in presence of dopamine and acetaminophen. Linear ranges and lowest detection limits for all three analytes were increased by 10 times for the sdPtFe2O3 compared to other Fe2O3 modified electrodes. The sensor is validated using commercially available pharmaceutical drugs used in therapeutics.  相似文献   
5.
Susruta Majumdar 《合成通讯》2013,43(23):3537-3548
We report a novel synthesis of N‐alkyl‐N‐alkyloxycarbonylaminomethyl (NANAOCAM) prodrugs of acetaminophen, theophylline, and 6‐mercaptopurine by alkylation of the corresponding drug molecule with N‐alkyl‐N‐alkyloxycarbonylaminomethyl chlorides in good yield. Most of the alkylating agents were efficiently synthesized by chloromethylation of N‐alkyl carbamic acid alkyl esters, which in turn were made from alkyl amines and alkyl chloroformates. In cases where the alkyl chloroformates were not available, synthesis of N‐alkyl carbamic acid alkyl esters was accomplished by converting an alcohol to a chloroformate or to an activated acylating agent such as acyl imidazoles or p‐nitrophenylcarbonate esters, followed by their reaction with alkyl amines.  相似文献   
6.
以在线扫集-胶束毛细管电动色谱法(Sweeping-MEKC)测定了复方氨酚烷胺胶囊中的马来酸氯苯那敏、咖啡因和对乙酰氨基酚3种有效成分。考察了缓冲溶液pH值、SDS浓度、分离电压及进样时间等对分离效果的影响。优化条件:以未涂层熔融石英毛细管(55 cm×50μm,有效柱长35 cm)为分离柱;环境温度25℃;80 mmol/L十二烷基磺酸钠+20 mmol/L NaH2PO4(pH 2.2)+15%乙腈为缓冲体系,分离电压-20kV,进样时间60 s(H=20.0 cm),测量波长210 nm。在该条件下氯苯那敏、咖啡因和对乙酰氨基酚在25min内出峰,峰面积RSD均小于4%;线性范围分别为2.45~39.17、1.61~25.76、1.58~25.28 mg/L;检出限(S/N=3)分别达139、34、24μg/L,回收率分别为96%~101%、98%~102%、96%~102%。  相似文献   
7.
碱性条件下,对乙酰氨基酚对鲁米诺-过氧化氢-纳米银化学发光体系有较强的抑制作用,基于此,结合流动注射技术,建立了测定对乙酰氨基酚的新方法。 研究了影响化学发光强度的各种因素,并初步探讨了可能的发光机理。 在最佳实验条件下,对乙酰氨基酚浓度在2.0×10-8~1.0×10-4 mol/L范围内与相对发光强度呈线性关系,检出限(3σ)为4.0×10-9 mol/L。 对1.0×10-7 mol/L的对乙酰氨基酚平行测定9次,相对标准偏差为2.6%。 该法用于片剂中扑热息痛含量的测定,结果令人满意。  相似文献   
8.
A sensitive and selective liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS) was developed and validated for the determination of salbutamol in human plasma and urine, and successfully applied to the pharmacokinetic study of salbutamol in Chinese healthy volunteers after inhalation of salbutamol sulfate aerosol. Salbutamol and the internal standard (IS) acetaminophen in plasma and urine were extracted with ethyl acetate, separated on a C18 reversed‐phase column, eluted with mobile phase of acetonitrile–ammonium acetate (5 m m ; 30:70, v/v), ionized by positive ion pneumatically assisted electrospray and detected in the multi‐reaction monitoring mode using precursor → product ions of m/z 240.2 → 148.1 for salbutamol and 152 → 110 for the IS. The lower limits of quantitation of salbutamol in human plasma and urine by this method were 0.02 and 1 ng/mL, respectively. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision and several stabilities were validated for salbutamol in human plasma and urine. In conclusion, the validation results showed that this method is robust, specific and sensitive, and can successfully fulfill the requirement of clinical pharmacokinetic study of salbutamol in healthy Chinese volunteers. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
9.
《Analytical letters》2012,45(2):365-375
Abstract

A reversed phase high-performance liquid chromatography (HPLC) method for simultaneous measurement of acetaminophen (I), acetylsalicylic acid (II), caffeine (III) and d-propoxyphene (IV), using phenacetin (V) as an internal standard was developed. Using a 6.5 μ C-8 reversed phase column (RPP) with a mobile phase consisting of 0.01M sodium acetate solution: methanol (85:15%) at pH 4.1 enabled the Chromatographic separation of the four components in about 12 min. Quantitation was achieved by measuring the peak height ratio of each component relative to the internal standard. the validity of the developed method was tested by analyzing laboratory-prepared mixtures containing the four components in various proportions. Assay precision and sensitivity have been established for each component. the developed method proved to be stability-indicating as it can be applied to monitor salicylic acid as a degradation product in acetylsalicylic acid samples.  相似文献   
10.
《Analytical letters》2012,45(11):2051-2058
Abstract

The use of partial least-squares spectrophotometric calibration for the simultaneous determination of suppositories in a multicomponent formulation is presented. This method is applied to the deternination of acetaminophen and phenobarbital in suppository preparations. The results show that these components in a molar ratio of about 61:1 in suppositories have been determined simultaneously with high precision.  相似文献   
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