全文获取类型
收费全文 | 1601篇 |
免费 | 93篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 97篇 |
妇产科学 | 23篇 |
基础医学 | 226篇 |
口腔科学 | 35篇 |
临床医学 | 129篇 |
内科学 | 330篇 |
皮肤病学 | 33篇 |
神经病学 | 76篇 |
特种医学 | 25篇 |
外科学 | 179篇 |
综合类 | 48篇 |
一般理论 | 3篇 |
预防医学 | 82篇 |
眼科学 | 57篇 |
药学 | 110篇 |
中国医学 | 4篇 |
肿瘤学 | 227篇 |
出版年
2023年 | 28篇 |
2022年 | 32篇 |
2021年 | 81篇 |
2020年 | 51篇 |
2019年 | 66篇 |
2018年 | 64篇 |
2017年 | 49篇 |
2016年 | 50篇 |
2015年 | 50篇 |
2014年 | 69篇 |
2013年 | 83篇 |
2012年 | 133篇 |
2011年 | 132篇 |
2010年 | 73篇 |
2009年 | 45篇 |
2008年 | 83篇 |
2007年 | 55篇 |
2006年 | 53篇 |
2005年 | 45篇 |
2004年 | 64篇 |
2003年 | 45篇 |
2002年 | 40篇 |
2001年 | 22篇 |
2000年 | 18篇 |
1999年 | 20篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1992年 | 5篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1973年 | 10篇 |
1972年 | 7篇 |
1970年 | 13篇 |
1969年 | 8篇 |
1968年 | 7篇 |
1967年 | 8篇 |
1939年 | 4篇 |
排序方式: 共有1698条查询结果,搜索用时 15 毫秒
71.
Uday?C?GhoshalEmail author Debashish?Guha Santu?Bandyopadhyay Chiranjib?Pal Srikanta?Chakraborty Ujjala?Ghoshal Tamal?K?Ghosh Bhaskar?B?Pal Prabir?K?Banerjee 《BMC gastroenterology》2002,2(1):6
Background
Helicobacter pylori (H. pylori) has been etiologically linked with primary gastric lymphoma (PGL) and gastric carcinoma (GC). There are a few reports of occurrence of both diseases in the same patient with H. pylori infection.Case presentation
We report a patient with PGL in whom the tumor regressed after surgical resection combined with eradication of H. pylori infection. However, he developed GC on follow up; this was temporally associated with recrudescence / re-infection of H. pylori. This is perhaps first report of such occurrence.Conclusions
Possible cause and effect relationship between H. pylori infection and both PGL and GC is discussed. This case also documents a unique problem in management of PGL in tropical countries where re-infection with H. pylori is supposed to be high.72.
Lesley A. Mathews Griner Rajarshi Guha Paul Shinn Ryan M. Young Jonathan M. Keller Dongbo Liu Ian S. Goldlust Adam Yasgar Crystal McKnight Matthew B. Boxer Damien Y. Duveau Jian-Kang Jiang Sam Michael Tim Mierzwa Wenwei Huang Martin J. Walsh Bryan T. Mott Paresma Patel William Leister David J. Maloney Christopher A. Leclair Ganesha Rai Ajit Jadhav Brian D. Peyser Christopher P. Austin Scott E. Martin Anton Simeonov Marc Ferrer Louis M. Staudt Craig J. Thomas 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(6):2349-2354
73.
May Chiew Heather F Gidding Aditi Dey James Wood Nicolee Martin Stephanie Davis Peter McIntyre 《Bulletin of the World Health Organization》2014,92(3):171-177
Objective
To estimate the measles effective reproduction number (R) in Australia by modelling routinely collected notification data.Methods
R was estimated for 2009–2011 by means of three methods, using data from Australia’s National Notifiable Disease Surveillance System. Method 1 estimated R as 1 − P, where P equals the proportion of cases that were imported, as determined from data on place of acquisition. The other methods estimated R by fitting a subcritical branching process that modelled the spread of an infection with a given R to the observed distributions of outbreak sizes (method 2) and generations of spread (method 3). Stata version 12 was used for method 2 and Matlab version R2012 was used for method 3. For all methods, calculation of 95% confidence intervals (CIs) was performed using a normal approximation based on estimated standard errors.Findings
During 2009–2011, 367 notifiable measles cases occurred in Australia (mean annual rate: 5.5 cases per million population). Data were 100% complete for importation status but 77% complete for outbreak reference number. R was estimated as < 1 for all years and data types, with values of 0.65 (95% CI: 0.60–0.70) obtained by method 1, 0.64 (95% CI: 0.56–0.72) by method 2 and 0.47 (95% CI: 0.38–0.57) by method 3.Conclusion
The fact that consistent estimates of R were obtained from all three methods enhances confidence in the validity of these methods for determining R. 相似文献74.
Ranjan Ku. Sahoo Nikhil Biswas Arijit Guha Nityananda Sahoo Ketousetuo Kuotsu 《药学学报(英文版)》2014,4(5):408-416
The aim of this study was to characterize the provesicle formulation of nateglinide (NTG) to facilitate the development of a novel controlled release system of NTG with improved efficacy and oral bioavailability compared to the currently marketed NTG formulation (Glinate™ 60). NTG provesicles were prepared by a slurry method using the non-ionic surfactant, Span 60 (SP), and cholesterol (CH) as vesicle forming agents and maltodextrin as a coated carrier. Multilamellar niosomes with narrow size distribution were shown to be successfully prepared by means of dynamic laser scattering (DLS) and field emission scanning electron microscopy (FESEM). The absence of drug-excipient interactions was confirmed by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. In vitro release of NTG in different dissolution media was improved compared to pure drug. A goat intestinal permeation study revealed that the provesicular formulation (F4) with an SP:CH ratio of 5:5 gave higher cumulative amount of drug permeated at 48 h compared to Glinate™ 60 and control. A pharmacodynamic study in streptozotocin-induced diabetic rats confirmed that formulation F4 significantly (P<0.05) reduced blood glucose levels in comparison to Glinate 60. Overall the results show that controlled release NTG provesicles offer a useful and promising oral delivery system for the treatment of type II diabetes.KEY WORDS: Provesicles, Niosomes, Maltodextrin, Nateglinide, In vitro release, Goat intestinal permeation, Hypoglycemic 相似文献
75.
Reinhard Wolf Martin Heisenberg Björn Brembs Scott Waddell Aditi Mishra Abigail Kehrer 《Journal of neurogenetics》2020,34(1):9-20
AbstractWe present here our reflections on the scientific work of the late Troy D. Zars (1967 – 2018), on what it was like to work with him, and what it means to us. A common theme running through his work is that memory systems are not for replaying the past. Rather, they are forward-looking systems, providing whatever guidance past experience has to offer for anticipating the outcome of future actions. And in situations where no such guidance is available trying things out is the best option. Working with Troy was inspiring precisely because of the optimism inherent in this concept and that he himself embodied. Our reflections highlight what this means to us as his former mentors, colleagues, and mentees, respectively, and what it might mean for the future of neurogenetics. 相似文献
76.
Sanjukta Guha Thakurta Mikail KraftHendrik J. Viljoen Anuradha Subramanian 《Acta biomaterialia》2014,10(11):4798-4810
Chondrocyte-seeded scaffolds were cultured in an ultrasound (US)-assisted bioreactor, which supplied the cells with acoustic energy around resonance frequencies (∼5.0 MHz). Polyurethane-polycarbonate (BM), chitosan (CS) and chitosan–n-butanol (CSB) based scaffolds with varying porosities were chosen and the following US regimen was employed: 15 kPa and 60 kPa, 5 min per application and 6 applications per day for 21 days. Non-stimulated scaffolds served as control. For BM scaffolds, US stimulation significantly impacted cell proliferation and depth-independent cell population density compared to controls. The highest COL2A1/COL1A1 ratios and ACAN mRNA were noted on US-treated BM scaffolds compared to controls. A similar trend was noted on US-treated cell-seeded CS and CSB scaffolds, though COL2A1/COL1A1 ratios were significantly lower compared to BM scaffolds. Expression of Sox-9 was also elevated under US and paralleled the COL2A1/COL1A1 ratio. As an original contribution, a simplified mathematical model based on Biot theory was developed to understand the propagation of the incident US wave through the scaffolds and the model analysis was connected to cellular responses. Scaffold architecture influenced the distribution of US field, with the US field being the least attenuated in BM scaffolds, thus coupling more mechanical energy into cells, and leading to increased cellular activity. 相似文献
77.
78.
79.
80.
Nirangkush Borah Amlan Jyoti Kalita Ankur kanti Guha Manash R. Das Chandan Tamuly 《RSC advances》2021,11(58):36698
In this work, a colorimetric approach for the detection of ascorbic acid (AA) and thyroxine (TH) was developed by synthesizing cost-effective silver nanoparticles (AgNPs) decorated with epigallocatechin gallate (EGCG) and CTAB. EGCG is the major bioactive chemical constituent that played a significant role in this study. The environment around the nanoparticle (NP) was controlled by adding CTAB surfactants. The synthesized NPs were characterized by different advanced techniques including XRD, XPS, SEM, and TEM. UV-visible spectra were thoroughly analyzed for sensing of AA and TH and the colour change of the solution can be visually monitored. The change in the localized surface plasmon resonance (LSPR) properties was used as an asset for the detection of AA and TH. A good linear relationship was obtained in both the sensing schemes with a limit of detection (LoD) of 0.67 μM and 0.33 μM for AA and TH respectively. Furthermore, the nanoparticles (NP) were implemented for real-sample analysis (pharmaceutical tablets). A cost-effective filter paper strip-based method coupled with smartphone scanning sensing was developed for the detection of AA. The interaction of AA and TH with the probe was depicted by a density functional theory (DFT) analysis. The synthesized NPs show tremendous selectivity towards AA and TH and excellent potential for practical applications.In this work, a colorimetric approach for the detection of ascorbic acid and thyroxine was developed by synthesizing cost-effective silver nanoparticles (AgNPs) decorated with epigallocatechin gallate (EGCG) and CTAB. 相似文献