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排序方式: 共有422条查询结果,搜索用时 15 毫秒
1.
自“缬沙坦事件”之后,N-亚硝胺类基因毒性杂质引起了业界的广泛关注。本文概述了药物中N-亚硝胺类基因毒性杂质和相关检测方法的研究进展,以及近20年来国内外有关药物中基因毒性杂质监管指南的完善历程。N-亚硝胺类基因毒性杂质作为一类高反应活性的基因毒性杂质,主要来源于药物合成过程中发生的副反应,以及药物在储存或者运输过程中发生的氧化或还原等反应。所有的动物实验表明,N-亚硝胺类具有很强的致癌性。在理论上,所有药物都存在N-亚硝胺类杂质或被N-亚硝胺类杂质污染的风险,由于该类化合物在药物中常以痕量形式存在,在分析检测过程中药物基质干扰大,因此建立便捷、高效的分析方法是非常有必要的。 相似文献
2.
C. Oprea P.J. Szalanski M.V. Gustova I.A. Oprea V. Buzguta 《Applied radiation and isotopes》2009,67(12):2142-2145
R-mode factor analysis was applied to characterize the chemical composition of human teeth investigated by particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and X-ray fluorescence (XRF) techniques. The approach developed in this study enabled the separation between essential mineral teeth components and the pollutants deposited in teeth tissues during the human life. The three independent sources of metals incorporated in human teeth were found. The first source, representing about 43% of the variance of the concentration data, was characterized by pollutant elements of power industry emissions. The second factor was loaded with toxic elements of general urban pollution. The third factor represented the tooth source as it contained mainly large fractions of the mineral components of the tooth tissue as Ca and K. 相似文献
3.
Jan Schmeller Michael Wessolly Elena Mairinger Sabrina Borchert Thomas Hager Thomas Mairinger Kurt Werner Schmid Jeremias Wohlschlaeger Robert F.H. Walter Fabian D. Mairinger 《Pathology, research and practice》2019,215(2):381-386
Introduction
The usage of formalin-fixed paraffin embedded (FFPE) tissue is characterized by its long shelf-life and simple handling. Therefore it is the most commonly available tissue specimen in routine diagnostics and histological studies. Formaldehyde fixation may result in RNA degradation and cross linking with proteins, while storage conditions also affect RNA integrity. The present study was designed to investigate the influence of these factors on RNA analysis.Design
FFPE-derived RNA from sections of 23 patients with spontaneous pneumothoraxes was used. Unstained sections of FFPE tissue were stored at various temperatures (?80?°C, ?20?°C, 4?°C, 24?°C) prior to RNA extraction. The potential impact on RNA quality of semi-automatic and manual RNA isolation and three different deparaffinization agents (mineral oil, xylene and d-limonene) were compared.Results
The storage temperature of FFPE sections affects RNA concentration and fragmentation, with the optimal storage temperature below -20?°C. The RNA extracted with d-limonene shows equivalent quality to the RNA extracted using more toxic standard agents. The manual isolation provides a higher RNA yield compared to the semi-automatic isolation. However, no differences in the amount of longer RNA fragments were observed. Furthermore, the semi-automatic isolation showed an enhanced RNA quality.Conclusion
FFPE sections not directly used for RNA extraction should be stored below -20?°C to increase quality and yield of the RNA. Usage of semi-automatic isolation produces superior results and simplifies routine processes by having less hands-on-time. Replacement of toxic xylene by d-limonene may contribute to improved occupational safety while not influencing analytical results. 相似文献4.
为改善技术论证的定量程度,作者用层析法对X-CT的选型操作进行了研究,并提出此方法可推广应用于一般医院的大型装备。 相似文献
5.
6.
Ferrara SD Brusini G Maietti S Frison G Castagna F Allevi S Menegus AM Tedeschi L 《International journal of legal medicine》1999,113(1):50-54
This paper describes the general design and main results of the Italian proficiency testing program for the analysis of psychoactive
substances in urine, a long-term initiative created in 1995 on an educational basis and characterized by an innovative internet-based
service for data exchange between laboratories and the organizing body. Batches of six urine samples, validated by reference
laboratories, are sent every 3 months to participating laboratories, which may choose which classes of substances to test
from those planned by the program panel and, within those classes, which type of analytical commitment to work on: identification
of just one class (Option 1), identification of single substances (Option 2), or identification and quantification of single
substances (Option 3). Comprehensive periodical reports and annual reports are provided to participants with evaluation of
their performance and an annual workshop is organized to discuss technical-scientific topics related to clinical, forensic
and analytical toxicology. About 200 laboratories currently participate in the program and a total of 67,059 analyses have
been carried out since 1995. The mean percentage of correct results was 96.8%, with a yearly improvement of about 0.4%. The
best average false positive and false negative rates were obtained for methadone (0.2% and 2.1% respectively) and cocaine
(0.3% and 2.2%). The worst average false positive rates were obtained for amphetamines and opiates (3.2% and 5.0%) and worst
average false negative rates for amphetamines, barbiturates and cannabinoids (17.4%, 30.7% and 19.9%).
Received: 29 June 1998 / Received in revised form: 23 February 1999 相似文献
7.
蛋白质不稳定性及其分析技术 总被引:1,自引:0,他引:1
蛋白质不稳定性包括两种形式:化学不稳定性和物理不稳定性,这两种不稳定性可采取不同的分析技术。了解蛋白质不稳定性及其分析技术在生物工程药物的质量控制中有十分重要的作用。 相似文献
8.
9.
Eun Hye Cho Rihwa Choi Eun-Suk Kang 《Scandinavian journal of clinical and laboratory investigation》2013,73(6):496-500
AbstractIgG consists of four subclasses: IgG1, IgG2, IgG3, and IgG4. Changes in the serum concentration of each subclass reflect different clinical situations, and quantification of each subclass is important to assess patients’ clinical states. Herein, we evaluated the analytical performance of the SPAPLUS turbidimetric analyzer (The Binding Site, Birmingham, UK) for IgG subclass. Precision, linearity, comparison with the BNII system (Siemens Healthineers, Erlangen, Germany), and reference interval were assessed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The repeatability and within-laboratory precision were within 5% for all IgG subclasses. The coefficient of determination (R2) was higher than 0.99 for the analytical measurement range in all IgG subclasses. Comparison between SPAPLUS and BNII revealed significant differences in IgG1, IgG3, and IgG4 (p?.0001). IgG1 and IgG4 values were lower in SPAPLUS than BNII. On the other hand, IgG3 values were higher in SPAPLUS than BNII. The SPAPLUS turbidimetric analyzer exhibited good analytical performance for quantification of four IgG subclasses. Because of the differences between SPAPLUS and BNII, follow-up test for disease monitoring should be performed with same instrument. 相似文献
10.
R. Peraman K. Bhadraya Y. Padmanabha Reddy C. Surayaprakash Reddy T. Lokesh 《Indian journal of pharmaceutical sciences》2015,77(6):751-757
By considering the current regulatory requirement for an analytical method development, a reversed phase high performance liquid chromatographic method for routine analysis of etofenamate in dosage form has been optimized using analytical quality by design approach. Unlike routine approach, the present study was initiated with understanding of quality target product profile, analytical target profile and risk assessment for method variables that affect the method response. A liquid chromatography system equipped with a C18 column (250×4.6 mm, 5 μ), a binary pump and photodiode array detector were used in this work. The experiments were conducted based on plan by central composite design, which could save time, reagents and other resources. Sigma Tech software was used to plan and analyses the experimental observations and obtain quadratic process model. The process model was used for predictive solution for retention time. The predicted data from contour diagram for retention time were verified actually and it satisfied with actual experimental data. The optimized method was achieved at 1.2 ml/min flow rate of using mobile phase composition of methanol and 0.2% triethylamine in water at 85:15, % v/v, pH adjusted to 6.5. The method was validated and verified for targeted method performances, robustness and system suitability during method transfer. 相似文献