全文获取类型
收费全文 | 7361篇 |
免费 | 507篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 174篇 |
妇产科学 | 104篇 |
基础医学 | 1096篇 |
口腔科学 | 125篇 |
临床医学 | 537篇 |
内科学 | 1615篇 |
皮肤病学 | 394篇 |
神经病学 | 524篇 |
特种医学 | 320篇 |
外科学 | 1181篇 |
综合类 | 172篇 |
一般理论 | 4篇 |
预防医学 | 365篇 |
眼科学 | 265篇 |
药学 | 369篇 |
中国医学 | 28篇 |
肿瘤学 | 604篇 |
出版年
2024年 | 11篇 |
2023年 | 63篇 |
2022年 | 113篇 |
2021年 | 203篇 |
2020年 | 138篇 |
2019年 | 175篇 |
2018年 | 196篇 |
2017年 | 168篇 |
2016年 | 221篇 |
2015年 | 237篇 |
2014年 | 331篇 |
2013年 | 305篇 |
2012年 | 555篇 |
2011年 | 515篇 |
2010年 | 285篇 |
2009年 | 266篇 |
2008年 | 388篇 |
2007年 | 383篇 |
2006年 | 338篇 |
2005年 | 397篇 |
2004年 | 331篇 |
2003年 | 276篇 |
2002年 | 305篇 |
2001年 | 237篇 |
2000年 | 226篇 |
1999年 | 186篇 |
1998年 | 70篇 |
1997年 | 53篇 |
1996年 | 51篇 |
1995年 | 50篇 |
1994年 | 42篇 |
1993年 | 38篇 |
1992年 | 84篇 |
1991年 | 81篇 |
1990年 | 73篇 |
1989年 | 88篇 |
1988年 | 97篇 |
1987年 | 66篇 |
1986年 | 50篇 |
1985年 | 44篇 |
1984年 | 35篇 |
1983年 | 39篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 26篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1974年 | 9篇 |
1969年 | 6篇 |
排序方式: 共有7940条查询结果,搜索用时 31 毫秒
71.
Laura E. Zweifler Amy J. Koh Stephanie Daignault-Newton Laurie K. McCauley 《Journal of bone and mineral research》2021,36(10):1979-1998
Parathyroid hormone (PTH) is produced by the parathyroid glands in response to low serum calcium concentrations where it targets bones, kidneys, and indirectly, intestines. The N-terminus of PTH has been investigated for decades for its ability to stimulate bone formation when administered intermittently (iPTH) and is used clinically as an effective anabolic agent for the treatment of osteoporosis. Despite great interest in iPTH and its clinical use, the mechanisms of PTH action remain complicated and not fully defined. More than 70 gene targets in more than 90 murine models have been utilized to better understand PTH anabolic actions. Because murine studies utilized wild-type mice as positive controls, a variety of variables were analyzed to better understand the optimal conditions under which iPTH functions. The greatest responses to iPTH were in male mice, with treatment starting later than 12 weeks of age, a treatment duration lasting 5–6 weeks, and a PTH dose of 30–60 μg/kg/day. This comprehensive study also evaluated these genetic models relative to the bone formative actions with a primary focus on the trabecular compartment revealing trends in critical genes and gene families relevant for PTH anabolic actions. The summation of these data revealed the gene deletions with the greatest increase in trabecular bone volume in response to iPTH. These included PTH and 1-α-hydroxylase (Pth;1α(OH)ase, 62-fold), amphiregulin (Areg, 15.8-fold), and PTH related protein (Pthrp, 10.2-fold). The deletions with the greatest inhibition of the anabolic response include deletions of: proteoglycan 4 (Prg4, −9.7-fold), low-density lipoprotein receptor-related protein 6 (Lrp6, 1.3-fold), and low-density lipoprotein receptor-related protein 5 (Lrp5, −1.0-fold). Anabolic actions of iPTH were broadly affected via multiple and diverse genes. This data provides critical insight for future research and development, as well as application to human therapeutics. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献
72.
Purpose: Lengthy hospitalization places a burden on patients and healthcare resources. However, the factors affecting the length of hospital stay (LHoS) and length of emergency room stay (LERS) in non-fatal bicycle accidents are currently unclear. We investigated these factors to inform efforts to minimize hospitalization.
Methods: We performed a retrospective analysis of data from non-fatal injured bicyclists admitted to the Emergency and Critical Care Center at Kyoto Medical Center between January 2012 and December 2016. We measured LHoS, LERS, mechanism of injury, head injury prevalence, polytrauma, operations performed, injury severity score (ISS), abbreviated injury scale (AIS) score, maximum AIS score, and trauma and injury severity score probability of survival. We conducted multiple regression analysis to determine predictors of LHoS and LERS.
Results: Within the study period, 82 victims met the inclusion and exclusion criteria and were included. Mean age was (46.0 ± 24.7) years. Overall mean LHoS was (16.8 ± 25.2) days, mean LERS was (10.6 ± 14.7) days, median ISS was 9 (interquartile range (IQR): 3-16), median maximum AIS was 3 (IQR: 1-4), and median trauma and injury severity score probability of survival was 98.0% (IQR: 95.5%-99.6%). Age, maximum AIS, ISS, and prevalence of surgery were significantly greater in long LHoS and LERS group compared with short LHoS and LERS group (p < 0.05). Performance of surgery independently explained LHoS (p = 0.0003) and ISS independently explained LERS (p = 0.0009).
Conclusion: Surgery was associated with long hospital stays and ISS was associated with long emergency room stays. To improve the quality life of the bicyclists, preventive measures for reducing injury severity or avoiding injuries needing operation are required. 相似文献
73.
Frederick H Koh Jason MW Chua Joselyn LJ Tan Fung-Joon Foo Winson J Tan Sharmini S Sivarajah Leonard Ming Li Ho Bin-Tean Teh Min-Hoe Chew 《World journal of gastrointestinal surgery》2021,13(8):734-755
A growing body of evidence has demonstrated the prognostic significance of sarcopenia in surgical patients as an independent predictor of postoperative complications and outcomes. These included an increased risk of total complications, major complications, re-admissions, infections, severe infections, 30 d mortality, longer hospital stay and increased hospitalization expenditures. A program to enhance recovery after surgery was meant to address these complications; however, compliance to the program since its introduction has been less than ideal. Over the last decade, the concept of prehabilitation, or “pre-surgery rehabilitation”, has been discussed. The presurgical period represents a window of opportunity to boost and optimize the health of an individual, providing a compensatory “buffer” for the imminent reduction in physiological reserve post-surgery. Initial results have been promising. We review the literature to critically review the utility of prehabilitation, not just in the clinical realm, but also in the scientific realm, with a resource management point-of-view. 相似文献
74.
Koh -ichi Enomoto Kishio Furuya Shunichi Yamagishi Takami Oka Takashi Maeno 《Pflügers Archiv : European journal of physiology》1994,427(5-6):533-542
Mechanical stimulation of one mammary tumor cell in culture induced an increase in its intracellular calcium concentration which spread to surrounding cells. The increase in calcium can also be induced by addition of a solution in which cultured mammary tumor cells were stimulated by repeated pipetting (solution after pipetting cells, SAPC). The activity of the SAPC was completely abolished by treatment with snake venom phosphodiesterase or pyrophosphatase. Uridine triphosphate (UTP), uridine diphosphate (UDP) and ATP (1 M each) were detected in the SAPC, whereas 5-UMP and 5-AMP were produced by phosphodiesterase digestion. A mixture of UTP, UDP and ATP (1 M each) elicited a calcium response which was comparable to that induced by SAPC, while UTP, UDP or ATP alone at 1 M elicited a small increase in calcium concentration in mammary tumor cells. Suramin, a competitive antagonist of P2 purinoceptors, diminished the spreading of the calcium wave induced by mechanical stimulation. It also blocked the responses to SAPC, UTP, UDP and ATP. These findings suggest that the mechanical stimulation results in the release of UTP, UDP and ATP into the extracellular space which mediates induction of the spreading calcium response via P2U-type purinoceptors. 相似文献
75.
76.
Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) uptake is known to be increased in breast cancer because of increased blood flow from angiogenesis and heightened metabolism. We performed a 99mTc-MIBI scan in a patient with mammary Paget's disease. The patient had underlying invasive cancer in the same side of the breast. 99mTc-MIBI scan exhibited a scintigraphic image of the uptake from the invasive cancer lesion located deeply in the breast toward the epidermis. 99mTc-MIBI showed an uptake in the deeply located invasive cancer lesion as well as nipple lesion. Especially, the delayed phase of Tc-MIBI scan demonstrated the tumor site more accurately. In conclusion, 99mTc-MIBI scan could be a useful adjunct to clinical decision making in the management of Paget's disease of the breast. 相似文献
77.
78.
Yamada Y Kubota T Hoshiya Y Asanuma F Koh J Kitajima M Coley H Judson I 《Oncology reports》1996,3(4):613-617
The antitumor effect of N-2, N-4, N-6-trihydroxymethyl-N-2, N-4, N-6-trimethylmelamine (trimelamol), a synthetic analogue of hexamethylmelamine, was investigated using human breast carcinoma xenografts in nude mice. Four tumor models, T-61, Br-10, R-27 and MCF-7 were estrogen receptor (ER)-positive and their growth was estradiol-dependent. The MX-1 model was ER-negative and grew estradiol-independently. Sixty mg of trimelamol per kg dissolved in 5% dimethylsulphoxide (DMSO) with 5% glucose was administered intraperitoneally for 5 days weekly for three weeks. Trimelamol showed potent antitumor activity on T-61 and MX-1 in a dose-responsive manner with a marginal effect on Br-10, whilst R-27 and MCF-7 were insensitive to this agent. This antitumor spectrum on human breast carcinoma xenografts was similar to that of hexamethylmelamine previously reported using the same xenograft models. Trimelamol is water-soluble and does not require metabolic activation which is needed for hexamethylmelamine. These advantages allow the paraenteral administration of trimelamol, and warrant the further investigation of this drug for breast carcinomas. 相似文献
79.
Osamu Mikami Shigenari Kawakita Kumiko Fujise Koh Shingu Hakuo Takahashi Tadashi Matsuda 《The Journal of urology》1996,155(4):1368-1371
Purpose
We evaluated plasma catecholamine levels during pneumoperitoneum in laparoscopic surgery.Materials and Methods
Plasma epinephrine and norepinephrine were evaluated in 29 patients who underwent laparoscopic retroperitoneal surgery in a half lateral decubitus position (group 1) or laparoscopic varicocelectomy in a Trendelenburg position (group 2).Results
The levels of epinephrine and norepinephrine increased significantly 5 minutes after carbon dioxide insufflation compared to levels after Veress needle insertion and just before insufflation. The elevation of catecholamine levels during laparoscopic procedures was greater in group 1.Conclusions
Our results indicate that carbon dioxide insufflation may cause catecholamine release during laparoscopic surgery. Careful monitoring of hemodynamics is mandatory at the beginning of the procedure. 相似文献80.
By a linear programming procedure, we have optimized the Jacobi room model to fit our data on the partitioning of radon daughters between air and wall surfaces (plateout), obtained at high radon concentrations in a small chamber. Subsequently, the optimized model yielded estimates that compared well with plateout data obtained at lower concentrations in a room-sized chamber. (The experimental work is described separately.) The major change made in the Jacobi model was to reduce the deposition velocity of free airborne radon daughters from 1 to 0.05 cm/sec. This value was obtained by using a fast algorithm to solve the linear programming to arrive at the "best fit". Lesser changes were made in other parameters. 相似文献