全文获取类型
收费全文 | 4834篇 |
免费 | 328篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 158篇 |
妇产科学 | 111篇 |
基础医学 | 736篇 |
口腔科学 | 134篇 |
临床医学 | 373篇 |
内科学 | 1157篇 |
皮肤病学 | 217篇 |
神经病学 | 548篇 |
特种医学 | 50篇 |
外科学 | 336篇 |
综合类 | 21篇 |
预防医学 | 414篇 |
眼科学 | 145篇 |
药学 | 389篇 |
中国医学 | 33篇 |
肿瘤学 | 341篇 |
出版年
2024年 | 3篇 |
2023年 | 39篇 |
2022年 | 92篇 |
2021年 | 177篇 |
2020年 | 101篇 |
2019年 | 179篇 |
2018年 | 181篇 |
2017年 | 135篇 |
2016年 | 150篇 |
2015年 | 158篇 |
2014年 | 221篇 |
2013年 | 255篇 |
2012年 | 447篇 |
2011年 | 433篇 |
2010年 | 241篇 |
2009年 | 197篇 |
2008年 | 348篇 |
2007年 | 300篇 |
2006年 | 276篇 |
2005年 | 290篇 |
2004年 | 258篇 |
2003年 | 225篇 |
2002年 | 231篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 32篇 |
1998年 | 30篇 |
1997年 | 26篇 |
1996年 | 21篇 |
1995年 | 15篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有5182条查询结果,搜索用时 31 毫秒
21.
22.
Susana Helm Scott K Okamoto Jay Maddock Donald Hayes Tonya Lowery Ranjani Rajan 《Hawai'i Journal of Medicine & Public Health》2013,72(2):66-69
This article briefly outlines a collaboration among communities on Hawai‘i Island and a university-based research team to develop, implement, and evaluate a school-based substance use prevention curriculum called Ho‘ouna Pono. In addition to providing a rationale for the project, the goal of this paper is fourfold. First, an overview of the Ho‘ouna Pono research results to date (2007–2013) is provided. Second, within this overview, the ways in which selected results informed program development are highlighted. Third, the curriculum is briefly described, and finally, the role of the students and community in the video production is described. 相似文献
23.
Andreia Coroas José G G de Oliveira Susana Sampaio Cátia Borges Isabel Tavares Manuel Pestana Maria D V de Almeida 《Journal of renal nutrition》2004,14(3):157-163
OBJECTIVE: Kidney transplantation restores renal filtration, although it does not achieve the function of 2 native kidneys, and with time it may involute back to chronic renal failure. We hypothesized that bioelectrical impedance analysis (BIA) might highlight differences for body compartments among kidney transplants (Tx) with different filtration rates. METHODS: Thirty transplantation patients (19 male, 11 female) were studied at 62.4+/-26.6 months postsurgery and were divided into 3 groups: good creatinine clearance (crCl, mL/min/1.73 m2; >65.0), borderline (35.0相似文献
24.
Thakar CV Arrigain S Worley S Yared JP Paganini EP 《Journal of the American Society of Nephrology : JASN》2005,16(1):162-168
The risk of mortality associated with acute renal failure (ARF) after open-heart surgery continues to be distressingly high. Accurate prediction of ARF provides an opportunity to develop strategies for early diagnosis and treatment. The aim of this study was to develop a clinical score to predict postoperative ARF by incorporating the effect of all of its major risk factors. A total of 33,217 patients underwent open-heart surgery at the Cleveland Clinic Foundation (1993 to 2002). The primary outcome was ARF that required dialysis. The scoring model was developed in a randomly selected test set (n = 15,838) and was validated on the remaining patients. Its predictive accuracy was compared by area under the receiver operating characteristic curve. The score ranges between 0 and 17 points. The ARF frequency at each score level in the validation set fell within the 95% confidence intervals (CI) of the corresponding frequency in the test set. Four risk categories of increasing severity (scores 0 to 2, 3 to 5, 6 to 8, and 9 to 13) were formed arbitrarily. The frequency of ARF across these categories in the test set ranged between 0.5 and 22.1%. The score was also valid in predicting ARF across all risk categories. The area under the receiver operating characteristic curve for the score in the test set was 0.81 (95% CI 0.78 to 0.83) and was similar to that in the validation set (0.82; 95% CI 0.80 to 0.85; P = 0.39). In conclusion, a score is valid and accurate in predicting ARF after open-heart surgery; along with increasing its clinical utility, the score can help in planning future clinical trials of ARF. 相似文献
25.
26.
Nephropathy associated with heroin abuse in Caucasian patients. 总被引:1,自引:0,他引:1
Maria do Sameiro Faria Susana Sampaio Victor Faria Elísio Carvalho 《Nephrology, dialysis, transplantation》2003,18(11):2308-2313
BACKGROUND: Renal disease is a complication of heroin addiction. Using renal biopsies in Caucasian patients, we studied the types of nephropathy associated with heroin abuse. METHODS: Nineteen renal biopsies were performed on heroin addicts between January 1993 and December 2001. The indications for renal biopsy included proteinuria with or without renal insufficiency. RESULTS: All 19 patients had serological evidence of hepatitis C virus (HCV) infection, one had hepatitis B virus surface antigen and three were HIV positive. Thirteen patients (68.4%) were found to have membranoproliferative glomerulonephritis (MPGN), 12 with type I and one with type III. Of the remaining patients, two had chronic interstitial nephritis, two had acute proliferative glomerulonephritis, one had amyloidosis and one had granulomatous glomerulonephritis with interstitial nephritis. No apparent decline in the incidence of renal disease was observed. CONCLUSIONS: In this cohort of male Caucasian heroin addicts, HCV-associated MPGN was the most frequent pattern of nephropathy, showing that the nephropathy associated with heroin abuse in Caucasians is not of the focal and segmental glomerulosclerosis type, in contrast to previous reports on African-Americans. This aspect may have important implications for patient management and prognosis. 相似文献
27.
Background We describe a new method to study the sensibility of the nipple-areola complex of the breast with faradic electricity delivered
through an electromyographic device used to monitor peripheral nerve conduction.
Methods The objective results of faradic pulses (2–50 mA per pulse) delivered to the nipple-areola complex of the breast through a
Nihon-Kohden II machine (Evoked potential/Electromyographs, Nihon-Kohden Co., Japan) were evaluated in normal volunteers to
get a basal measure that was defined by the patient as “a soft electric discharge.” The measures were recorded and their output
discharges averaged (at least 5 to each complex).
Results Twenty-eight volunteers with normal breasts, 28 patients with breast hypertrophy before and after breast reduction, and 28
patients before and after breast augmentation were studied. The faradic pulses were perceived from 1.5 to 3.5 mA in the areola
and from 3 to 5.5 mA in the nipple in the control group and from 4.5 to 7.0 mA in the areola and from 6.5 to 9.5 mA in the
nipple in the breast hypertrophy group with no significant changes before and after surgery. In the breast augmentation group
the faradic pulses were very similar to the volunteers that had normal breasts, but 13 months after breast augmentation with
silicone gel prosthesis, a difference was found because all the patients had a higher threshold and three cases had lost sensibility
of the nipple-areola complex.
Conclusion In normal breasts the areola had a lower threshold for faradic pulses compared to the nipple. Hypertrophic breasts had a higher
threshold to the faradic stimulation than normal subjects in the pre- and postoperative period. Hypoplastic breasts before
breast augmentation had a perception threshold similar to that of the normal volunteers but after breast augmentation this
perception was much higher.
This study received the Scientific Exhibit Award at the ASAPS/ASERF Annual Meeting in Vancouver, British Columbia, Canada,
2005. 相似文献
28.
Labombarda F Gonzalez SL Gonzalez DM Guennoun R Schumacher M de Nicola AF 《Journal of neurotrauma》2002,19(3):343-355
Progesterone (PROG) exerts beneficial and neuroprotective effects in the injured central and peripheral nervous system. In the present work, we examine PROG effects on three measures of neuronal function under negative regulation (choline acetyltransferase [ChAT] and Na,K-ATPase) or stimulated (growth-associated protein [GAP-43]) after acute spinal cord transection injury in rats. As expected, spinal cord injury reduced ChAT immunostaining intensity of ventral horn neurons. A 3-day course of intensive PROG treatment of transected rats restored ChAT immunoreactivity, as assessed by frequency histograms that recorded shifts from predominantly light neuronal staining to medium, dark or intense staining typical of control rats. Transection also reduced the expression of the mRNA for the alpha3 catalytic and beta1 regulatory subunits of neuronal Na,K-ATPase, whereas PROG treatment restored both subunit mRNA to normal levels. Additionally, the upregulation observed for GAP-43 mRNA in ventral horn neurons in spinal cord-transected rats, was further enhanced by PROG administration. In no case did PROG modify ChAT immunoreactivity, Na,K-ATPase subunit mRNA or GAP-43 mRNA in control, sham-operated rats. Further, the PROG-mediated effects on these three markers were observed in large, presumably Lamina IX motoneurons, as well as in smaller neurons measuring approximately <500 micro2. Overall, the stimulatory effects of PROG on ChAT appears to replenish acetylcholine, with its stimulatory effects on Na,K-ATPase seems capable of restoring membrane potential, ion transport and nutrient uptake. PROG effects on GAP-43 also appear to accelerate reparative responses to injury. As the cellular basis for PROG neuroprotection becomes better understood it may prove of therapeutic benefit to spinal cord injury patients. 相似文献
29.
María de Oña Navarro Santiago Melón Susana Méndez Beatriz Iglesias Ana Palacio María J. Bernardo José L. Rodriguez-Lambert Ernesto Gómez 《Transplant international》2002,15(11):570-573
Ganciclovir (GCV) prophylaxis or pre-emptive therapy significantly reduce the rate of cytomegalovirus (CMV) disease and viremia, but increase the potential for emergence of ganciclovir-resistant CMV strains. The inhibitor concentration at 50% (IC(50)) of GCV from 156 CMV isolates from 59 renal or heart transplant recipients was calculated by means of a rapid phenotypic susceptibility assay. Twenty-seven strains were from 14 patients undergoing GCV therapy. The IC(50) was higher in patients under the prophylaxis regimen. One CMV strain, from a heart transplant recipient, became GCV-resistant after 1 month of therapy (IC(50)=13.7 micromol/l). These data, together with clinical and virological markers, suggested that a switch to foscarnet was necessary, and good evolution was observed. Thus, assay of CMV susceptibility to GCV could be helpful in clinical management. 相似文献
30.
Mechanism of vascular smooth muscle cells activation by hydrogen peroxide: role of phospholipase C gamma. 总被引:2,自引:0,他引:2
Francisco R González-Pacheco Carlos Caramelo Maria Angeles Castilla Juan J P Deudero Javier Arias Susana Yagüe Sonsoles Jiménez Rafael Bragado Maria Victoria Alvarez-Arroyo 《Nephrology, dialysis, transplantation》2002,17(3):392-398
BACKGROUND: Hydrogen peroxide (H2O2) formation is a critical factor in processes involving ischaemia/ reperfusion. However, the precise mechanism by which reactive oxygen species (ROS) induce vascular damage are insufficiently known. Specifically, activation of phospholipase C gamma (PLCgamma) is a probable candidate pathway involved in vascular smooth muscle cells (VSMC) activation by H2O2. METHODS: The activation of human venous VSMC was measured as cytosolic free calcium mobilization, shape change and protein phosphorylation, focusing on the role of tyrosine phosphorylation-activated PLCgamma. RESULTS: The exposure of VSMC to exogenous H2O2 caused a rapid increase in cytosolic free calcium concentration ([Ca2+]i), and induced a significant VSMC shape change. Both effects were dependent on a tyrosine kinase-mediated mechanism, as determined by the blockade of short-term treatment of VSMC with the protein tyrosine kinase inhibitor, genistein. Giving further support to the putative role of phospholipase C (PLC)-dependent pathways, the [Ca2+]i and VSMC shape change response were equally inhibited by the specific PLC blocker, 1-(6-((17-beta-methoxyestra-1,3,5(10)trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). In addition, U73122 had a protective effect against the deleterious action (24 h) of H2O2 on non-confluent VSMC. As a further clarification of the specific pathway involved, the exposure to H2O2 significantly stimulated the tyrosine phosphorylation of PLCgamma with a concentration- and time-profile similar to that of [Ca(2+)](i) mobilization. CONCLUSIONS: The present study reveals that H(2)O(2) activates PLCgamma on VSMC through tyrosine phosphorylation and that this activation has a major role in rapid [Ca(2+)](i) mobilization, shape-changing actions and damage by H(2)O(2) in this type of cells. These findings have direct implications for understanding the mechanisms of the vascular actions of H(2)O(2) and may help to design pharmacologically protective strategies. 相似文献