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81.
Franz Mlynek Markus Himmelsbach Wolfgang Buchberger Christian W. Klampfl 《Electrophoresis》2021,42(4):482-489
The (tentative) identification of unknown drug-related phase II metabolites in plants upon drug uptake remains a challenging task despite improved analytical instrument performance. To broaden the knowledge of possible drug metabolization, a fast-screening approach for the tentative identification of drug-related phase II metabolites is presented in this work. Therefore, an in silico database for the three non-steroidal anti-inflammatory drugs (ketoprofen, mefenamic acid, and naproxen) and a sub-group of their theoretical phase II metabolites (based on combinations with glucose, glucuronic acid, and malonic acid) was created. Next, the theoretical exact masses (protonated species and ammonia adducts) were calculated and used as precursor ions in an autoMS/MS measurement method. The applicability of this workflow was tested on the example of eleven edible plants, which were hydroponically grown in solutions containing the respective drug at a concentration level of 20 mg/L. For the three drugs investigated this led to the tentative identification of 41 metabolites (some of them so far not described in this context), such as combinations of hydroxylated mefenamic acid with up to four glucose units or hydroxylated mefenamic acid with two glucose and three malonic acid units. 相似文献
82.
《Arabian Journal of Chemistry》2022,15(12):104346
The current research is focused on development of machine learning model for estimation of pharmaceutical solubility in supercritical CO2 as the green solvent. The main aim is to assess the suitability of supercritical processing for preparation of nanomedicine. Oxaprozin was taken as model drug for the solubility measurements, and its solubility was determined at different operational conditions by variation of temperature and pressure of the process. Artificial Neural Network (ANN) model was implemented for simulation of the drug solubility, and the best model was obtained with R2 greater than 0.99 for the training and validation as well. The tested model was then exploited to understand the process, and it turned out that both pressure and temperature had major and considerable influence on the solubility of Oxaprozin in supercritical carbon dioxide as solvent. However, the effect of pressure was shown to be more significant on the solubility compared to the effect of pressure, which was attributed to the effect of pressure on the density of the supercritical solvent. The developed ANN model was indicated to be robust in estimating the values of drug solubility in wide range of conditions which can save time and cost of the measurements. 相似文献
83.
Pure-component electrostatic properties for pharmaceutical compounds and intermediates (xanthene, ibuprofen, aspirin, p-hydroxyphenylacetic acid, p-toluic acid and o-anisic acid) were obtained by quantum-chemical methods. Afterwards, these properties were used for the a priori determination of the pure-component parameters for the Perturbed-Chain Polar Statistical-Associating Fluid Theory (PCP-SAFT). These parameters were applied to perform solubility calculations for binary solute–solvent mixtures. In these calculations the only parameter fitted was the binary parameter. The results show a good agreement of the modeled solubility and experimental data for the considered solutes in non-polar and polar solvents. Finally, the application of different combination rules to also predict the binary interaction parameter in the mixture was investigated. 相似文献
84.
Clinton A. Krueger Christopher K. Hilton Mark Osgood Jianglin Wu Ching Wu 《International Journal for Ion Mobility Spectrometry》2009,12(1):33-37
Current commercially available ion mobility spectrometers are intended for the analysis of chemicals in the gas phase. Sample
introduction methods, such as direct air sampling, a GC injector or a thermal desorber, are commonly an integral part of these
instruments. This paper describes an electrospray ionization ion mobility spectrometer system that allows direct introduction
samples in solution phase. This allows direct analysis of non-volatile organic and biological samples, and avoids decomposition
of thermally liable samples, providing reliable chemical identification. In addition, the new ion mobility spectrometer allows
mobility analysis with high resolving power. Commonly used commercial IMS systems provide resolving powers between 10 and
30; this new ion mobility spectrometer has resolving power greater than 60 for routine analysis. A high resolution instrument
is necessary for many applications where a complex mixture needs to be separated and quantified. This paper demonstrates the
advantages of using a high resolution ion mobility spectrometer and an electrospray ionization source for the analysis of
non-volatile pharmaceuticals as well as dissolved explosive in solution phase. 相似文献
85.
Kahina Si-Ahmed Fairouz Tazerouti Ahmed Y. Badjah-Hadj-Ahmed 《Analytical and bioanalytical chemistry》2009,395(2):507-518
In order to study the effect of the nature and the length of the spacer, three mixed 10-undecenoate/phenylcarbamate derivatives
of β-cyclodextrin have been prepared and linked to allylsilica gel by means of a radical reaction. The chiral recognition
ability of the resulting materials, when used as liquid chromatography chiral stationary phases (CSPs), was evaluated using
heptane and either 2-propanol or chloroform as organic mobile-phase modifiers. A large variety of racemic compounds have been
separated successfully on these CSPs (mainly pharmaceuticals and herbicides). Optimization of these separations was discussed
in terms of mobile-phase composition and structural patterns of the injected analytes. The efficiencies of the three prepared
materials were compared to those of previously described perphenylated-β-cyclodextrin column and to analogous cellulose derivative-based
CSPs.
Schematic illustration of the b-cyclodextrin/mandelic acid inclusion complex 相似文献
86.
Solid phase extraction and HPLC determination of veterinary pharmaceuticals in wastewater 总被引:1,自引:0,他引:1
This work focuses on the application of SPE-HPLC analysis of important veterinary pharmaceuticals from different classes in highly complex wastewater matrix. The pharmaceutical investigated included three sulfonamides (sulfamethazine, sulfadiazine and sulfaguanidine), a sulfonamide synergist (trimethoprim), a tetracycline (oxytetracycline), a fluoroquinolone (enrofloxacine) and a β-lactame (penicillin G/procaine). The method involves pre-concentration and clean-up by solid phase extraction (SPE) using Oasis HLB extraction catridges. Final analysis of the selected pharmaceutical compounds was carried out by high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD). Recoveries were ranged from 68.3 to 97.9% with relative standard deviation below 8.4%. Only for sulfaguanidine low recovery was obtained. Limits of quantification were in the range 1.5-100 μg/L depending on pharmaceutical. The described method was applied to the determination of pharmaceuticals in wastewater samples from pharmaceutical industry. 相似文献
87.
The principle of sequential injection (SI) was exploited to develop a fully automated pre-column derivatization procedure combined on-line to liquid chromatography (LC). Using SI-LC derivatization 14 amino acids were determined fluorimetrically in pharmaceuticals with o-phthaldialdehyde (OPA) as the derivatization reagent. The SI system was used for the handling of samples and reagents, on-line mixing and introduction to the LC injection system. Chemical (pH and reagents concentrations) and instrumental variables (sample and reagent volumes, reaction time and flow rate) were optimized to attain the highest reaction yield and detector signal. Reversed phase chromatographic resolution of 14 amino acids was achieved within 35 min using gradient elution. The automated operation of the coupled SI-LC system resulted in very satisfactory performance. The method was applied for the simultaneous determination of amino acids in pharmaceutical formulations. 相似文献
88.
Trace-level determination of pharmaceutical residues by LC-MS/MS in natural and treated waters. A pilot-survey study 总被引:1,自引:0,他引:1
Hernando MD Heath E Petrovic M Barceló D 《Analytical and bioanalytical chemistry》2006,385(6):985-991
A pilot-survey study was performed by collecting samples (influent and effluent wastewaters, rivers and tap waters) from different
locations in Europe (Spain, Belgium, Germany and Slovenia). A solid-phase extraction (SPE) followed by liquid chromatography–tandem
mass spectrometry method was applied for the determination of pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac
and clofibric acid). Method detection limits and method quantification limits were at the parts-per-trillion level (7.5–75 ng/L).
The recovery rates of the SPE from deionized water and effluent wastewater samples spiked at 100- and 1,000-ng/L levels ranged
from 87 to 95%. Identification criteria in compliance with the EU regulation for confirmatory methods of organic residues
were applied. A detailed study of signal suppression evaluation for analysis of pharmaceutical residues in effluent wastewaters
is presented. 相似文献
89.
Phototoxicity testing by online irradiation and HPLC 总被引:1,自引:0,他引:1
A high-performance liquid chromatography (HPLC) system was developed for the determination of drug photostability and phototoxicity
based on an automated column-switching system with aqueous online UV-A irradiation and hyphenated organic separation of the
drug and its photoproducts. The photoreactor is built with an poly(ethylene-co-tetrafluoroethylene) (ETFE) reaction coil knitted around a UV-A light source. The chromatographic separation was performed
with two special C18 columns, which are also suitable for using with pure water as eluent. Degradation of chlorpromazine (CPZ) by ultraviolet
light was investigated at pH 7 and pH 3. Furthermore chlorpromazine was irradiated in the presence of guanosine-5-monophosphate
(GMP) in pH 7 buffered solution, leading to a new photoproduct. In the pH 3 irradiation studies of CPZ and GMP, no reaction
was detected between the molecules. 相似文献
90.
Electrochemical sensor employing edge-plane pyrolytic graphite electrode (EPPGE) for the sensitive detection of hydrocortisone (HC) is delineated for the first time. The electrochemical properties are investigated exercising the cyclic voltammetry and square-wave voltammetry (SWV). When equating with the bare basal-plane pyrolytic graphite electrode (BPPGE), the EPPGE gave better response towards the detection of HC both in terms of sensitivity and detection limit. The voltammetric results indicated that EPPGE remarkably enhances the reduction of HC which leads to considerable amelioration of peak current with shift of peak potential to less negative values. The difference in the surface morphology of two electrodes has been studied. Also, the EPPGE delivered an analytical performance for HC with a sensitivity of 45 nA nM−1 and limit of detection of 88 nM in the concentration range 100-2000 nM. The method has been utilized for the determination of HC in pharmaceuticals and real samples. The electroanalytical method using EPPGE is the most sensitive method for determination of HC with lowest limit of detection to date. The major metabolites present in blood plasma did not intervene with the present investigation as they did not exhibit reduction peak in the experimental range used. A comparison of results with high performance liquid chromatography (HPLC) signalizes a good agreement. 相似文献