全文获取类型
收费全文 | 405109篇 |
免费 | 68321篇 |
国内免费 | 21134篇 |
专业分类
耳鼻咽喉 | 4376篇 |
儿科学 | 8065篇 |
妇产科学 | 6258篇 |
基础医学 | 52686篇 |
口腔科学 | 10847篇 |
临床医学 | 56524篇 |
内科学 | 71718篇 |
皮肤病学 | 10783篇 |
神经病学 | 30080篇 |
特种医学 | 14003篇 |
外国民族医学 | 170篇 |
外科学 | 45978篇 |
综合类 | 53035篇 |
现状与发展 | 74篇 |
一般理论 | 55篇 |
预防医学 | 25652篇 |
眼科学 | 10766篇 |
药学 | 39735篇 |
298篇 | |
中国医学 | 19249篇 |
肿瘤学 | 34212篇 |
出版年
2024年 | 987篇 |
2023年 | 4962篇 |
2022年 | 12514篇 |
2021年 | 17170篇 |
2020年 | 16595篇 |
2019年 | 20508篇 |
2018年 | 20688篇 |
2017年 | 20905篇 |
2016年 | 20700篇 |
2015年 | 25690篇 |
2014年 | 29216篇 |
2013年 | 28220篇 |
2012年 | 28593篇 |
2011年 | 31196篇 |
2010年 | 25461篇 |
2009年 | 18643篇 |
2008年 | 19995篇 |
2007年 | 18938篇 |
2006年 | 18732篇 |
2005年 | 17983篇 |
2004年 | 12037篇 |
2003年 | 11249篇 |
2002年 | 9609篇 |
2001年 | 8570篇 |
2000年 | 8677篇 |
1999年 | 8379篇 |
1998年 | 4731篇 |
1997年 | 4626篇 |
1996年 | 3750篇 |
1995年 | 3485篇 |
1994年 | 2952篇 |
1993年 | 1867篇 |
1992年 | 2763篇 |
1991年 | 2382篇 |
1990年 | 1934篇 |
1989年 | 1648篇 |
1988年 | 1544篇 |
1987年 | 1329篇 |
1986年 | 1069篇 |
1985年 | 822篇 |
1984年 | 534篇 |
1983年 | 418篇 |
1982年 | 246篇 |
1981年 | 241篇 |
1980年 | 185篇 |
1979年 | 299篇 |
1978年 | 170篇 |
1977年 | 144篇 |
1974年 | 156篇 |
1972年 | 139篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
61.
62.
Ramesh R Boinpally Sen Lin Zhou Srinivasu Poondru Gopinath Devraj Bhaskara R Jasti 《European journal of pharmaceutics and biopharmaceutics》2003,56(3):389-392
Skin penetration of topically applied diclofenac is important for the treatment of rheumatic diseases and actinic keratoses. We have studied the permeation of diclofenac across human cadaver epidermis in-vitro from four lecithin vesicle formulations and a few marketed semi-solid preparations. The lecithin vesicle formulations were prepared by dissolving the lipid contents (lecithin and sodium cholate) in a 1:1 mixture of methanol-chloroform, evaporating the solvents under vacuum, and hydrating the lipid layer with the drug solution in water or 10% ethanol. The vesicles were sonicated for 5 min to reduce the vesicle size and their size and Zeta potential were characterized. The cumulative amount and maximum flux of diclofenac was 69.7+/-40.3 micrograms and 4.77+/-3.16 micrograms/hcm(2) from lecithin vesicles containing sodium cholate and 10% ethanol, and is the highest of all formulations studied. The cumulative amount and mean maximum flux obtained from other formulations were in the range of 2.46+/-1.98-29.9+/-10.1 micrograms and 0.53+/-0.46-3.61+/-0.86 micrograms/hcm(2). Based on the results, lecithin vesicles of diclofenac appear to be advantageous for the topical delivery of diclofenac. 相似文献
63.
64.
Abstract – Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long‐term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow‐up period of 9 months. 相似文献
65.
Sandra Urdaneta Hartmann Brian Wigdahl Elizabeth B Neely Cheston M Berlin Cara-Lynne Schengrund Hung-Mo Lin Mary K Howett 《Journal of human lactation》2006,22(1):61-74
Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk. 相似文献
66.
67.
The neutral lipids existing in the intercellular spaces of the stratum corneum (SC) provide a permeability barrier to prevent water loss. Nile red is the most sensitive lipid stain for tissue sections. However, due to the extremely flattened morphology of corneocytes and the resolution limits of the light microscope, Nile red staining is seldom used as a fluorescent probe for the lipid-rich SC. In this study, we modified the traditional method for visualization of intracellular lipid by adding 4% potassium hydroxide after Nile red staining. This modified method not only allowed visualization of lipids existing in the intercellular membrane regions and the lateral junctions of the adjoining corneocytes, but also clearly demonstrated small lipid droplets within pathological corneocytes. These features were not observed with the traditional staining method. Thus, this modified Nile red staining method greatly improved the resolution of the SC lipids under light microscopy and should be useful for studying lipid depositions in both normal and pathological SC. 相似文献
68.
A. Varkey N. C. Tan R. Girotto W. C. Tang Y. T. Liu H. C. Chen 《ANZ journal of surgery》2007,77(Z1):A62-A62
Purpose Post operative monitoring is crucial for the success of microsurgical free tissue transfer. Sophisticated and expensive methods are available for monitoring. We propose a novel technique using digital photography and the internet as a reliable and cost effective method to monitor free tissue transfers. Methods 163 micro‐vascular procedures were monitored using this technique over 8 months. Serial photographs taken to show flap color. Capillary refill time, pin prick‐ bleed time and color and hand held Doppler signal was recorded in the movie mode of a standard 5 mega pixel camera with duration of 15 seconds. Data was sent to the surgeon at regular intervals and or as deemed necessary. Results Analysis of the 67 cases is presented. 5 re‐explorations were done. The early diagnosis of venous congestion was possible using this technique. Timely intervention contributed to the success of the re‐explorations and these flaps could be salvaged. The file size of images was in the range of 1 MB–6 MB. The file size of an entire set of images ranged about 7 MB–9 MB. These were sent across the ADSL internet lines. Conclusion The use of the digital images and the internet allow reconstructive surgeons to have a reliable picture of the state of their free tissue transfers. This permits decrease in observer error and saves valuable time which otherwise needs to be spent to verify situations of doubt and offers an ideal solution to the logistic problem of having to visit the patient in case of doubt. 相似文献
69.
After a comprehensive rernew of the literature on syphilitic
aortitis, Longcope, (1) stated in 1913; ": . . . the presence of spiro:
chetes in these lesions, as might be expected, cannot by any means be
constantly demonstrated with Levaaiti stain. . . . . . . That these
organisms are ''Treponema pallidum seems almost certain thouS:h actual
proof of such by culture from the arterial lesions, a most difficult task,
or direct inoculation into animals, has not as yet been accomplished." 相似文献
70.
A conjugate of antisense oligodeoxynucleotide (AS ODN) covalently linked with deoxorubicin (DOX) was synthesized. Its properties and antitumour activity in human carcinoma DOX resistant cells (KB-A-1) were investigated in vitro. The results showed that the conjugate was strongly stable both in Dulbecco's Phosphate-Buffered Saline (PBS) and in culture medium. The intracellular concentration of the conjugate was higher than that of the AS DON by HPLC analysis. The conjugate showed potent dose-dependent inhibition to the growth of KB-A-1 cells. Chemosensitivity of KB-A-1 cells to DOX was also investigated in vitro. When the cells were first exposed to the conjugate (0.5 microM) and then exposed to DOX for 24 h, the IC50 value of DOX decreased from 21.5 to 2.2 microM. In contrast, when treated with the mixture of the same concentration of the AS ODN with equivalent DOX, the IC50 value of DOX was 16.8 microM. Intracellular DOX concentration was detected in KB-A-1 treatment with the conjugate in vitro by HPLC. The results showed that the intracellular DOX concentration was 6.4-fold increased in KB-A-1 cells treated with the conjugate compared to treatment with DOX alone. In contrast, 1.8-fold increasing was observed when treated with the AS ODN. Western blot analysis showed a significantly decrease in the amount of P-glycoprotein in KB-A-1 cells. These results suggest that the conjugate is effective in reversing multidrug resistance. Certainly, further studies are conducting to explore the antitumour effect of the conjugate in vivo. 相似文献