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排序方式: 共有106条查询结果,搜索用时 18 毫秒
81.
K. Krawielitzki R. Schadereit U. Herrmann 《Isotopes in environmental and health studies》2013,49(8):262-269
In einem Versuch mit wachsenden Ratten werden die Resorption, die Retention und die intermediäre Verteilung des 15N nach zehntägiger Verabfolgung von vier verschiedenen 15N-Tracern: DL-(15N)-Methionin, L-(15N)-Lysin, (15N)-Glycin und (15NH4)2SO4 untersucht und die Übertragungsprozesse der markierten Aminogruppe (Transaminierung, Desaminierung und Aminierung sowie andere chemische Umwandlungen zwischen den Aminosäuren) bestimmt. Die Ergebnisse werden diskutiert und daraus Schluβfolgerungen für die Eignung der Substanzen zur Markierung von Organismen bzw. als Tracer für die Bestimmung von Parametern des Protein- und Aminosäurenstoffwechsels abgeleitet. In an experiment with growing rats the resorption, the incorporation and the intermediate fate of 15N were estimated using four different 15N-tracers: DL·(15N)-methionine, L·(15N)-lysine, (15N)-glycine and (15N4)2SO4. Transformation of the labelled amino group by transamination, by desamination and amination as well as by other chemical processes of amino acids will be checked. The results are discussed and conclusions are drawn for the use of 15N -substances as a labelling substance of organisms respectively as a tracer for estimating parameters of the whole body protein and amino acid metabolism. 相似文献
82.
《Biomedical chromatography : BMC》2017,31(5)
In this study, a reliable method for the quantitation of (E )‐N ‐benzyl‐6‐[2‐(3, 4‐dihydroxy benzylidene)hydrazinyl]‐N ‐methylpyridine‐3‐sulfonamide (JW‐55) in rat plasma was developed and validated using high‐performance liquid chromatography. Plasma samples were deproteinized; sildenafil was used as an internal standard. Chromatographic separation was achieved using a reversed‐phase C18 column. The mobile phase, 0.02 m ammonium acetate buffer:acetonitrile (48:52, v /v), was run at a flow rate of 1.0 mL/min at room temperature, and the column eluent was monitored using an ultraviolet detector at 280 nm. The retention times of JW‐55 and sildenafil were ~5.9 and 7.7 min, respectively. The detection limit of JW‐55 in rat plasma was 0.03 μg/mL. Pharmacokinetic parameters of JW‐55 were evaluated after intravenous and oral administration of JW‐55 (10 mg/kg) in rats. After oral administration, the F value was approximately 73.7%. 相似文献
83.
Zhanying Hong Guojun Cai Wentao Ma Jun Wen Yifeng Chai Guorong Fan 《Biomedical chromatography : BMC》2012,26(6):749-753
A rapid high‐performance liquid chromatographic method was developed and validated for determination of tetrahydropalmatine (THP), an active component of Rhizoma Corydalis, in rat plasma. The samples were prepared using protein precipitation and separated on an Agilent XDB‐C18 column (150 × 4.6 mm, 5 µm) with the mobile phase consisting of methanol–0.1% phosphate acid solution, adjusted with triethylamine to pH 5.5 (65:35). Good linearity was found within 0.10–10.00 µg/mL of THP in rat plasma sample. The intra‐ and inter‐day precision values were less than 10%. The developed method was successfully applied to assess the pharmacokinetics of THP in spontaneously hypertensive rats (SHR) and normotensive rats. After oral administration of a single dose of THP (60 mg/kg), the maximum plasma concentrations were 6.15 ± 2.1 and 7.54 ± 2.9 µg/mL for normotensive rats and SHR, respectively. The mean values of AUC0–∞ of THP in SHR were 81.44 ± 45.0 µg h/mL, significantly higher (p < 0.05) than in normotensive rats (44.06 ± 19.6 µg h/mL). The t1/2 and MRT in SHR were much longer than that in healthy Sprague–Dawley rats, indicating slow elimination of THP in SHR. The results indicated that there are some differences in pharmacokinetics of THP in SHR and Sprague–Dawley rats and it is very important to investigate the pharmacokinetic properties of drugs in pathological conditions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
84.
Following intravenous injections of [15N]glycine (97 at.% 15N, 400 mg in 1.5 ml isotonic saline) to Lewis rats several organs were excised. The time courses of the 15N NMR spectral (40.55 MHz) were measured at 37°C after cold (4°C) or warm (37°C) storage. The application of the Overhauser POE technique yielded signal enhancement by a factor of -2.7 and -1.3 in sceletal and heart muscle, respectively, at 37°C, but no enhancement in liver and kidney. In the time course of liver measurements at 37°C, intermediate metabolic products of glycine were observed, such as serine, glutamine, alanine, and tryptophane. 相似文献
85.
Xiujie Chen Lei Liu Zhizhong Sun Yongsheng Liu Jiankai Xu Sibo Liu Bangqing Huang Ling Ma Zhiguo Yu Kaishun Bi 《Biomedical chromatography : BMC》2010,24(8):826-832
Accurate and reproducible HPLC methods were developed and validated for the determination of concentrations of luteolin (LT) and tetra‐acetyl‐luteolin (TALT) in rat plasma. HPLC analyses were performed on an Agilent TC‐C18 column protected by a guard Agilent Zorbax Eclipse Plus. The mobile phase for LT was a binary mixture of acetonitrile–water (40:60, v/v) containing 0.5% phosphoric acid at a flow rate of 1.0 mL/min, and that for TALT was a binary mixture of methanol–water (70 : 30, v/v) containing 0.5% glacial acetic acid at the same flow rate. The UV detection wavelength for both analytes was set at 350 nm. The calibration curve was linear over the range of 40–1800 ng/mL, the lower limit of quantitation was 40 ng/mL and the lower limit of detection was 20 ng/mL for both LT and TALT. The intra‐ and inter‐day precision (RSD) values for all samples were within 7.9%. The concentration–time curves of LT and TALT after oral administration (30 mg/kg) were both fitted to a two‐compartment model. The pharmacokinetic characteristics of TALT were better than that of LT in the maximum plasma concentration (Cmax) and the area under the concentration–time curve (AUC). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
86.
S. Kossakowski A. Dziura A. Grosicki 《Isotopes in environmental and health studies》2013,49(8):387-389
The experiment was performed on 192 Wistar rats irradiated with 154.5 mC kg?1. Therefore, the animals were divided into 5 groups and were treated as follows: group I, controls, with Cs-137; groups II and III with Cs-137 followed by 2-fold administration of ferric ferrocyanide (FF) and ammonium ferric-cyanoferrate (AFCF), respectively; groups IV and V with Cs-137 followed by 6-fold and 10-fold administration of FF and AFCF, respectively. Organ and muscle (16 samples) concentrations of Cs-137 in groups I–III were measured on days 1, 3, 5 and 7, and those of groups IV – V on day 7 after the contamination. The results indicated that in rats contaminated internally with Cs-137 one day post irradiation 2-fold treatment with FF and AFCF in the day resulted in a similar and significant decrease of Cs-137, whereas manyfold treatment (6× or 10×) with these agents did not increase their decontamination effectiveness. 相似文献
87.
Y. M. Megahed M. F. Abdel-Wahab S. M. El-Mougi F. B. El-Sayed 《Isotopes in environmental and health studies》2013,49(12):402-405
The importance of prolactin in vertebrates physiology has become appreciated only with the last 10 years. Prolactin appears t o have widespread metabolic action. As yet the basic action o f prolactin on protein, carbohydrates, lipids and other metabolic pathway have been studied as mentioned by Kompiang et al. [5] and Thurston et al. [11]. 相似文献
88.
Malgorzata Szafarz Joanna Szymura‐Oleksiak Agnieszka Zakrzewska Maria Walczak Kamil Kus Anna Gonciarz 《Biomedical chromatography : BMC》2013,27(1):73-79
A sensitive and specific liquid chromatography electrospray ionization–mass spectrometry method for determination of 1,4‐dimethylpyridinium (1,4‐DMP) in rat plasma has been developed and validated. Chromatography was performed on an Aquasil C18 analytical column (4.6 × 150 mm, 5 µm, Thermo Scientific, Rockford, IL, USA) with isocratic elution using a mobile phase containing acetonitrile and water with an addition of 0.1% of formic acid. Detection was achieved by an Applied Biosystems MDS Sciex (Concord, Ontario, Canada) API 2000 triple quadrupole mass spectrometer. Electrospray ionization was used for ion production. The limit of detection in the single ion monitoring mode was found to be 10 ng/mL. The limit of quantification was 50 ng/mL. The precision and accuracy for both within‐day and between‐day determination of 1,4‐dimethylpyridinium was 2.4–7.56 and 90.93–111.48%. The results of this analytical method validation allow pharmacokinetic studies to be carried out in rats. The method was used for the pilot study of the pharmacokinetic behavior of 1,4‐DMP in rats after intravenous administration. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
89.
Mohga S. Abd Allah S. E. A. Farag M. A. Abo-zaid 《Isotopes in environmental and health studies》2013,49(1):67-73
The possibility of reducing toxic substances in olive by-products subjected as animal feed stuffs after oil extraction was investigated. Total phenols in fresh olive fruits were 0.6%(fruit),0.7%(woody pit) and 0.31%in cakes after extraction. Irradiation of the olive cake powder at different doses (0,10,50 and 100 kGy) was done as a trial to remove the toxic substances. The results proved that irradiation decreases total phenols of olive cake from 0.31% (control) to 0.21, 0.16 and 0.08%at the doses used, respectively. Subcutaneously injected ethanolic extract of unirradiated or irradiated (with 10 kGy) olive cake was lethal to the rats, while at 50 and 100 kGy all rats survived. Liver and heart functions were measured in terms of activities of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), total protein and lactic acid dehydrogenase (LDH). In addition, plasma total lipids, cholesterol, triglycerides, glucose and blood heamoglobin were measured. Results obtained showed that the toxic substances in olive cake induced toxicosis symptoms with the experimental rats treated with the irradiated (50 kGy) samples. The toxic compounds could be destroyed at an irradiation dose level of 100 kGy without harmful effects on liver and heart functions as well as heamoglobin, carbohydrate and lipid metabolisms. After further investigations, irradiation with 100 kGy shall be recommended to be used for detoxication of olive by-products for animal feeding without deleterious side effects. 相似文献
90.
Within the framework of clinico-pharmacological and balneological studies it was the task of the authors to gather evidence on the progress, hitherto understood only little, and treatment of acute D20 intoxication. 相似文献