全文获取类型
收费全文 | 9531篇 |
免费 | 753篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 229篇 |
妇产科学 | 248篇 |
基础医学 | 1632篇 |
口腔科学 | 188篇 |
临床医学 | 1127篇 |
内科学 | 1731篇 |
皮肤病学 | 263篇 |
神经病学 | 1354篇 |
特种医学 | 325篇 |
外科学 | 853篇 |
综合类 | 70篇 |
一般理论 | 8篇 |
预防医学 | 683篇 |
眼科学 | 228篇 |
药学 | 505篇 |
中国医学 | 13篇 |
肿瘤学 | 775篇 |
出版年
2024年 | 20篇 |
2023年 | 134篇 |
2022年 | 192篇 |
2021年 | 392篇 |
2020年 | 257篇 |
2019年 | 346篇 |
2018年 | 387篇 |
2017年 | 302篇 |
2016年 | 382篇 |
2015年 | 406篇 |
2014年 | 472篇 |
2013年 | 536篇 |
2012年 | 843篇 |
2011年 | 817篇 |
2010年 | 480篇 |
2009年 | 407篇 |
2008年 | 591篇 |
2007年 | 574篇 |
2006年 | 524篇 |
2005年 | 486篇 |
2004年 | 419篇 |
2003年 | 375篇 |
2002年 | 368篇 |
2001年 | 46篇 |
2000年 | 41篇 |
1999年 | 56篇 |
1998年 | 65篇 |
1997年 | 59篇 |
1996年 | 47篇 |
1995年 | 43篇 |
1994年 | 42篇 |
1993年 | 21篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 15篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1976年 | 4篇 |
1972年 | 6篇 |
1965年 | 4篇 |
1933年 | 4篇 |
1926年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 702 毫秒
21.
Analysis of epidermal growth factor receptor and activated epidermal growth factor receptor expression in pituitary adenomas and carcinomas. 总被引:2,自引:0,他引:2
Onder Onguru Bernd W Scheithauer Kalman Kovacs Sergio Vidal Long Jin Shuya Zhang Katharina H Ruebel Ricardo V Lloyd 《Modern pathology》2004,17(7):772-780
Epidermal growth factor receptor plays an important role in the pathogenesis of many malignancies. Various growth factors, including epidermal growth factor receptor, have been shown to influence pituitary tumor growth and differentiation. To analyze the role of epidermal growth factor receptor in pituitary tumor development, we examined normal pituitaries (n=8), pituitary adenomas (n=158), and pituitary carcinomas (n=7) for expression of epidermal growth factor receptor protein and messenger RNA using tissue microarrays and RT-PCR. We also examined (a) the expression of phospho-epidermal growth factor receptor, the activated form of epidermal growth factor receptor, in pituitary tumors and normal pituitaries by immunohistochemistry and (b) the effects on epidermal growth factor receptor expression of treating pituitary cells (HP75 cell line) with epidermal growth factor. Epidermal growth factor receptor and the phosphorylated variant expression were present in normal pituitary cells. Epidermal growth factor receptor messenger RNA was also detected in normal pituitaries, pituitary adenomas, and carcinomas by in situ hybridization and RT-PCR. Most pituitary adenomas showed expression of epidermal growth factor receptor and the phosphorylated variant. Nonfunctional adenomas showed higher levels of expression of epidermal growth factor receptor (76 vs 34%) and of phospho-epidermal growth factor receptor (26 vs 8%) as compared to functional adenomas. Five of seven pituitary carcinomas showed strong expression of both epidermal growth factor receptor and phospho-epidermal growth factor receptor. When a human pituitary cell line (HP75) was cultured in the presence of epidermal growth factor receptor, there was an increase in the levels of both epidermal growth factor receptor and phospho-epidermal growth factor receptor after 5 h of treatment, thus confirming that epidermal growth factor receptor signaling was active in pituitary tumors. These results indicate that activated epidermal growth factor receptor is expressed in pituitary adenomas and carcinomas. Higher levels in pituitary carcinomas suggest a role in pituitary tumor progression. 相似文献
22.
Christian Rüegg Martin Hersberger Barbara Wusk Katharina Rentsch Gerd A Kullak-Ublick Arnold von Eckardstein Friedrich E Maly 《Clinical chemistry and laboratory medicine》2004,42(5):494-498
Crohn's disease is a complex disorder, with multiple genetic traits. A frameshift mutation (Leu1007fsinsC) and two missense mutations (Gly908Arg and Arg702Trp) in the NOD2/CARD15 gene are strongly associated with susceptibility to Crohn's disease. The presence of one of these risk alleles confers a 2- to 4-fold increase in the risk of developing Crohn's disease, and the presence of two mutant alleles increases the risk over 20-fold. To facilitate the analysis of these polymorphisms, we developed three LightCycler assays to detect the missense mutations Arg702Trp and Gly908Arg and the frameshift mutation Leu100fsinsC in the NOD2/ CARD15 gene. All three assays can be run simultaneously on one LightCycler using identical cycling parameters. Analysis of 53 DNAs from Crohn's patients helped to identify carriers at allele frequencies similar to other Caucasian populations. The sequencing of such DNAs confirmed the accuracy of the assays. In conclusion, we present three rapid and robust assays to detect the Arg702Trp, the Gly908Arg and the Leu1007fsinsC ins mutations in the NOD2/CARD15 gene [corrected] 相似文献
23.
Abstract. Registered nurses regarded as “experienced and good” in dementia care were interviewed about the feeding of a severely demented patient who showed refusal-like feeding behaviour. Not one of the twenty nurses could see herself using force against her patients. Most interviewees justified their decisions to feed a severely demented patient and answered questions about whether they would change their minds if there were certain circumstances in terms of words that could be interpreted as referring to the ethical principle of beneficence. The nurses stressed the difficulty to understand the meaning of severely demented patients' feeding behaviour and decide when force-feeding occurs. When asked to rank ethical principles of importance for the decision, however, the most common answer was that they would give priority to the ethical principle of autonomy. The nurses did not see the ethical principles as separate entities, that could be applied one by one, but tried to integrate them into a whole. The findings of this study were interpreted as indicating that principled ethics is not an adequate model to describe experienced nurses' ethical reasoning. 相似文献
24.
Dr. Carsten Herskind Katharina Fleckenstein Jens Lohr Chuan-Yuan Li Frederik Wenz Frank Lohr 《Strahlentherapie und Onkologie》2004,180(4):187-193
BACKGROUND: During the last 2 decades, cytokines such as interferons (IFN) have been used to modulate tumor response in radiotherapy. Initially, the focus was on antiviral and radiosensitizing effects of interferons but increasingly, the function of interferons and interleukins (IL) within the immune response to tumor cells is becoming important. METHOD: The cellular immune response toward tumor cells is reviewed. The role of cytokines in antigen presentation and activation of effector cells and their interactions with radiation are described. Preclinical strategies of the antitumor action of cytokines are presented and discussed based on the induction of IFN-gamma by IL-12. RESULTS: Recent advances in immunology have demonstrated the importance of local interactions between antigen-presenting cells (APC) and effector cells such as natural killer (NK) cells and T-lymphocytes for an effective immune reaction against tumors. Interferons stimulate such interactions, while IL-2 plays a central role in the activation of NK cells and T-lymphocytes. The interactions between APC and effector cells are suppressed by many tumors but can be stimulated by irradiation. Since systemic application of interferons is quite toxic, present strategies aim at local expression, e. g., the induction of IFN-gamma expression in Th1 cells by IL-12. CONCLUSION: The improved understanding of immunologic mechanisms has emphasized the role of the cytokine network in the interaction between tumor cells and effector cells such as NK cells and T-lymphocytes. This opens new possibilities for the application of cytokines as biological response modifiers, which may eventually help widening the therapeutic window in radiotherapy. 相似文献
25.
Thomas Rosemann Michel Wensing Katharina Joest Matthias Backenstrass Cornelia Mahler Joachim Szecsenyi 《BMC musculoskeletal disorders》2006,7(1):48-9
Background
Osteoarthritis (OA) is highly prevalent and has substantial impact on quality of life as well as on healthcare costs. The general practitioner (GP) often is the first care provider for patients with this chronic disease. The aim of this study was to identify health care needs of patients with OA and to reveal possible obstacles for improvements in primary care management of OA patients. 相似文献26.
Astrid R. R. Heutelbeck Carsten Junghans Hermann Esselmann Ernst Hallier Thomas G. Schulz 《International archives of occupational and environmental health》2009,82(9):1123-1131
Introduction
Cattle are an important source of allergens in the working area of farmers. Asthma caused by cow allergens is a significant occupational problem. Yet in allergological testing, the results of in vivo and in vitro diagnostic tests are often inconsistent even in cases with clearly cattle-related symptoms. 相似文献27.
Shahrokh Taghavi Katharina Krenn Peter Jaksch Walter Klepetko Seyedhossein Aharinejad 《American journal of transplantation》2005,5(6):1548-1552
Bronchiolitis obliterans (BO) is a survival-limiting factor in lung transplantation. There are no common BO markers in use. Since BO is associated with extracellular matrix remodeling, we asked whether matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) could serve as BO markers. In 72 lung transplant patients (34 BO syndrome (BOS) 0, 15 BOS 0-p, and 23 BOS 1) serum and broncho-alveolar lavage (BAL) MMP and TIMP levels were examined by ELISA. The BAL cell counts were additionally analyzed. The serum MMP-2, MMP-8, MMP-9 and TIMP-2 levels were not different in all groups. In contrast, the BAL MMP-8, -9 and TIMP-1 levels were significantly elevated in BOS 0-p (p = 0.003; p = 0.007; p = 0.0003, respectively) and BOS 1 (p = 0.003; p = 0.001; p = 0.0004, respectively) as compared to BOS 0 patients. The BAL MMP-8, -9 and TIMP-1 levels were significant predictors of BOS 0-p (p = 0.01; p = 0.01; p = 0.01, respectively) and BOS-1 (p = 0.007; p = 0.01; p = 0.006, respectively) in receiver operating characteristic analysis. Except for BAL macrophages that were significantly decreased in BOS 0-p versus BOS 0 patients; other cell counts were not different between the groups. BAL MMP-8, -9 and TIMP-1 might be useful markers to detect BO in lung transplant patients. 相似文献
28.
Michael J. Schull MD MSc Therese A. Stukel PhD Marian J. Vermeulen MHSc Astrid Guttmann MDLM MSc Merrick Zwarenstein MD PhD 《Academic emergency medicine》2006,13(11):1228-1231
Background Current influenza pandemic models predict a surge in influenza‐related hospitalizations in affected jurisdictions. One proposed strategy to increase hospital surge capacity is to restrict elective hospitalizations, yet the degree to which this measure would meet the anticipated is unknown. Objectives To compare the reduction in hospitalizations resulting from widespread nonurgent hospital admission restrictions during the Toronto severe acute respiratory syndrome (SARS) outbreak with the expected increase in admissions resulting from an influenza pandemic in Toronto. Methods The authors compared the expected influenza‐related hospitalizations in the first eight weeks of a mild, moderate, or severe pandemic with the actual reduction in the number of hospital admissions in Toronto, Ontario, during the first eight weeks of the SARS‐related restrictions. Results Influenza modeling for Toronto predicts that there will be 4,819, 8,032, or 11,245 influenza‐related admissions in the first eight weeks of a mild, moderate, or severe pandemic, respectively. In the first eight weeks of SARS‐related hospital admission restrictions, there were 3,654 fewer hospitalizations than expected in Toronto, representing a modest 12% decrease in the overall admission rate (a reduction of 1.40 admissions per 1,000 population). Therefore, influenza‐related admissions could exceed the reduction in admissions resulting from restricted hospital utilization by 1,165 to 7,591 patient admissions, depending on pandemic severity, which corresponds to an excess of 0.44 to 2.91 influenza‐related admissions per 1,000 population per eight weeks, and an increase of 4% to 25% in the overall number of admissions, when compared with nonpandemic conditions. Conclusions Pandemic modeling for Toronto suggests that influenza‐related admissions would exceed the reduction in hospitalizations seen during SARS‐related nonurgent hospital admission restrictions, even in a mild pandemic. Sufficient surge capacity in a pandemic will likely require the implementation of other measures, including possibly stricter implementation of hospital utilization restrictions. 相似文献
29.
Astrid Capello Eric P Krenning Bert F Bernard Wout A P Breeman Martin P van Hagen Marion de Jong 《Journal of nuclear medicine》2004,45(10):1716-1720
Receptor-targeted scintigraphy and radionuclide therapy with radiolabeled somatostatin analogs are successfully applied for somatostatin receptor-positive tumors. The synergistic effects of an apoptosis-inducing factor, for example, the Arg-Gly-Asp (RGD) motif, can increase the radiotherapeutic efficacy of these peptides. Hence, the tumoricidal effects of the hybrid peptide RGD-diethylaminetriaminepentaacetic acid (DTPA)-Tyr3-octreotate (cyclic[c](Arg-Gly-Asp-D-Tyr-Asp)-Lys(DTPA)-D-Phe-c(Cys-Tyr-D-Trp-Lys-Thr-Cys)-Thr), hereafter referred to as RGD-DTPA-octreotate, were evaluated in comparison with those of RGD (c(Arg-Gly-Asp-D-Tyr-Asp)) and Tyr3-octreotate (D-Phe-c(Cys-Tyr-D-Trp-Lys-Thr-Cys)-Thr). METHODS: The therapeutic effects of RGD-111In-DTPA-octreotate, 111In-DTPA-RGD, and 111In-DTPA-Tyr3-octreotate were investigated with various cell lines by use of a colony-forming assay, and caspase-3 activity was also determined. RESULTS: Tumoricidal effects were found with 111In-DTPA-RGD, 111In-DTPA-Tyr3-octreotate, and RGD-111In-DTPA-octreotate, in order from least effective to most effective. Also, the largest increase in caspase-3 levels was found with RGD-111In-DTPA-octreotate. CONCLUSION: RGD-111In-DTPA-octreotate has more pronounced tumoricidal effects than 111In-DTPA-RGD and 111In-DTPA-Tyr3-octreotate, because of increased apoptosis, as indicated by increased caspase-3 activity. 相似文献
30.
Eric Goodyer Frank Müller Katharina Licht Markus Hess 《European archives of oto-rhino-laryngology》2007,264(6):631-635
The shear modulus of the vocal fold is an essential parameter required to enhance our understanding of how the vocal fold
operates, to develop mathematical models of phonatation, and to provide benchmarks to quantify the effectiveness of surgical
procedures. The authors announced the successful deployment of an instrument to measure vocal fold elasticity in vivo last
year, and now present the data taken from eight patients in vivo. The shear modulus was measured at the mid-membranous point,
in a transverse direction with respect to the axis drawn between the anterior commissure and vocal process. The range of mean
shear modulus results is 701–2,225 Pa, with a mean value of 1,371 Pa. 相似文献