全文获取类型
收费全文 | 16055篇 |
免费 | 935篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 412篇 |
妇产科学 | 203篇 |
基础医学 | 2529篇 |
口腔科学 | 300篇 |
临床医学 | 1340篇 |
内科学 | 3370篇 |
皮肤病学 | 470篇 |
神经病学 | 1668篇 |
特种医学 | 796篇 |
外科学 | 2281篇 |
综合类 | 57篇 |
一般理论 | 7篇 |
预防医学 | 806篇 |
眼科学 | 495篇 |
药学 | 1141篇 |
中国医学 | 16篇 |
肿瘤学 | 1093篇 |
出版年
2023年 | 91篇 |
2022年 | 137篇 |
2021年 | 272篇 |
2020年 | 191篇 |
2019年 | 216篇 |
2018年 | 275篇 |
2017年 | 250篇 |
2016年 | 330篇 |
2015年 | 344篇 |
2014年 | 492篇 |
2013年 | 587篇 |
2012年 | 932篇 |
2011年 | 959篇 |
2010年 | 661篇 |
2009年 | 613篇 |
2008年 | 1059篇 |
2007年 | 1114篇 |
2006年 | 1095篇 |
2005年 | 1127篇 |
2004年 | 1004篇 |
2003年 | 940篇 |
2002年 | 915篇 |
2001年 | 282篇 |
2000年 | 194篇 |
1999年 | 226篇 |
1998年 | 252篇 |
1997年 | 197篇 |
1996年 | 162篇 |
1995年 | 155篇 |
1994年 | 110篇 |
1993年 | 122篇 |
1992年 | 87篇 |
1991年 | 93篇 |
1990年 | 93篇 |
1989年 | 99篇 |
1988年 | 125篇 |
1987年 | 90篇 |
1986年 | 87篇 |
1985年 | 84篇 |
1984年 | 65篇 |
1983年 | 66篇 |
1982年 | 84篇 |
1981年 | 46篇 |
1980年 | 60篇 |
1979年 | 44篇 |
1978年 | 49篇 |
1977年 | 50篇 |
1976年 | 53篇 |
1974年 | 39篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Stanley C. Jordan Klaus Kucher Morten Bagger Hans‐Ulrich Hockey Kristina Wagner Noriko Ammerman Ashley Vo 《American journal of transplantation》2020,20(9):2581-2588
Awareness of drug‐drug interactions is critical in organ transplant recipient management. However, biologic agents interfering with monoclonal antibodies is not widely considered. We report the effect of high‐dose intravenous immunoglobulin (IVIg) on safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of the human anti‐C5 monoclonal antibody tesidolumab (LFG316) in end‐stage renal disease patients awaiting kidney transplant. In this single‐center, phase 1, open‐label, parallel‐group study, 8 patients were assigned to receive either single‐dose tesidolumab + IVIg or tesidolumab alone, with 56‐day follow‐up. Within‐group PK parameters were consistent. Mean tesidolumab exposure decreased 34%, clearance increased 63%, and half‐life decreased 41% comparing tesidolumab + IVIg to tesidolumab alone. IVIg influence on tesidolumab elimination was most evident in the first 3 weeks. Complete suppression of both total and alternative complement activities was maintained for 4 weeks in the tesidolumab alone group and for 2 weeks in the tesidolumab + IVIg group. Tesidolumab was well tolerated. IVIg infused before tesidolumab affected tesidolumab PK and PD, resulting in a shortened period of full complement activity inhibition. These findings suggest a clinically relevant impact of IVIg on monoclonal antibody clearance and indirectly hint at an IVIg mechanism of action in treating autoimmune diseases and allosensitization by accelerating pathogenic IgG antibody degradation. Trial registration number: NCT02878616. 相似文献
62.
Juergen Hetzel Michael Kreuter Christian M. Khler Hans-Joachim Kabitz Andreas Gschwendtner Ralf Eberhardt Ulrich Costabel Kaid Darwiche 《Sarcoidosis, vasculitis, and diffuse lung diseases : official journal of WASOG / World Association of Sarcoidosis and Other Granulomatous Disorders》2021,38(1)
Background:Bronchoalveolar lavage (BAL) is a widely used clinical tool in diagnosing interstitial lung diseases. Although there are recommendations and guidelines, the procedure is not completely standardized. Varying approaches likely influence the conclusiveness of BAL data and may be one reason for the divergent judgement of their value between different centers.Objectives:To evaluate how BAL is performed in Germany using an electronically based survey.Methods:We conducted a cross-sectional online survey among all members of the German Respiratory Society.Results:608 members responded to the survey and of these 500 perform lavages. Most bronchoscopists (344/500) do not use a tube and have no anesthesiologist present during the procedure (405/500). Propofol is used by 76.8% and midazolam by 67.9% (n = 405), often in combination. A major difference was noted regarding the total volume of instillation. Many respondents use a predefined fixed amount of instilled volume (202/500), whereas an almost equal number use variable volumes based on the recovery (196/500). The minimum recovery volume predefined by 217/499 ranged from 3-150 ml (median 30 ml; mean 42.2 ± 55.1 ml). Most respondents did not transport their samples in special medium (61.5%) or on ice (72.8%). The average time between recovery and arrival at the lab was 115.6±267.0 min (n = 323).Conclusion:This study shows the broad spectrum of variations in the performance of BAL in Germany, which could have a negative effect on the method’s clinical value. There is a need for training and standardization of BAL performance. 相似文献
63.
Eickhoff A van Dam J Jakobs R Kudis V Hartmann D Damian U Weickert U Schilling D Riemann JF 《The American journal of gastroenterology》2007,102(2):261-266
OBJECTIVES: Unsedated colonoscopy is an uncomfortable procedure for most patients. Discomfort during colonoscopy is largely related to looping of the colonoscope, which displaces the colon from its native configuration and stretches attachments to the mesentery. A novel computer-assisted colonoscope utilizes a fully articulated, computer-controlled insertion tube. On manual insertion of the colonoscope, the position and angle of the scope's tip are encoded into a computer algorithm. As the colonoscope is advanced, the computer directs each successive segment to take the same shape that the tip had at a given insertion depth. The insertion tube thus changes its shape at different insertion depths in a "follow-the-leader" manner. METHODS: This initial clinical trial with this novel colonoscopy system was designed as a prospective, nonrandomized, unblinded, feasibility study. Three physicians of varying levels of experience participated in the study. RESULTS: Eleven consecutive patients (seven men, four women, age range 19-80) meeting inclusion criteria for screening or diagnostic colonoscopy were enrolled in the study. The cecum was reached in 10 consecutive patients (100%). Findings included diverticular disease in two cases and multiple colonic polyps in two cases. Postprocedure assessment at discharge, 48 h, and 30 days revealed no complications or adverse effects. Physician satisfaction and patient acceptance of this new technique were high. CONCLUSIONS: In this limited, first of its kind feasibility study, the computer-assisted colonoscope was shown to perform colonoscopy safely and effectively. The colonoscope's unique design limited loop formation during colonoscopy. Large-scale clinical trials are indicated. 相似文献
64.
Rauch U Hänsgen A Hagl C Holland-Cunz S Schäfer KH 《International journal of colorectal disease》2006,21(6):554-559
Background The human enteric nervous system (ENS) descends from migrating neural crest cells (NCC) and is structured into different plexuses embedded in the gastrointestinal tract wall. The development of this entity strongly depends on the supply of an appropriate support with trophic factors during organogenesis. The lack of important factors, such as glial cell line-derived neurotrophic factor, leads to severe disturbances in the ENS and, thus, to motility disorders in children. The isolation of neuronal precursor cells as well as their transplantation after expansion in vitro is therefore a hopeful new approach concerning all forms of dysganglionosis in children.Methods We therefore established a way to isolate and expand precursor cells from the developing and postnatal human ENS. Bowel samples were obtained from human fetuses and children (from the 9th week of gestation to 5 years postnatal). Myenteric plexus was isolated by enzymatical digestion and cultivated until spheroid aggregates, the so-called neurospheres, developed. These neurospheres could be differentiated and also be transplanted after dissociation into aganglionic bowel in vitro.Results Enteric neurospheres could be grown from different gestational ages, including postmortem material. Undifferentiated proliferating precursor cells were kept in culture for up to 72 days and could be differentiated in neurons and glial cells in vitro.Conclusion The first results using isolated enteric neurospheres in aganglionic bowel are quite promising and are a basis to develop an appropriate cell therapy for all kinds of dysganglionosis, especially for cases where a surgical approach is not sufficient or not even possible. 相似文献
65.
18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) does not visualize follicular lymphoma of the duodenum 总被引:1,自引:0,他引:1
<p>18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has been used as a potential tool for imaging nodal follicular lymphoma (FL) and extranodal spread. As primary intestinal FL is increasingly being recognized, we have performed a study to investigate the usefulness of 18F-FDG-PET for staging of extranodal FL within the gastrointestinal tract. In eight patients with a diagnosis of FL localized in the duodenum (six cases in stage I and one each in stages II and IV, respectively) whole body 18F-FDG-PET scans were performed. Seven patients with duodenal FL were rated WHO grade 1 and one had FL grade 3, while both patients with secondary spread had FL WHO grade 1. All patients were imaged before initiation of therapy. None of the patients with primary duodenal FL showed pathologically elevated 18F-FDG uptake. 18F-FDG-PET findings were not influenced by histological grade or proliferative activity of FL. These findings suggest that 18F-FDG-PET is not useful for clinical assessment of primary duodenal FL. 相似文献
66.
Gottfried Mayer Vitali Vogel J?rg Weyermann Dirk Lochmann Jacomina A van den Broek Christos Tziatzios Winfried Haase Daan Wouters Ulrich S Schubert Andreas Zimmer J?rg Kreuter Dieter Schubert 《Journal of controlled release》2005,106(1-2):181-187
Nanoparticles prepared by self-assembly from oligonucleotides (ONs), protamine free base, and human serum albumin ("ternary proticles") are spheres of diameters around 200 nm. Substitution of the protamine free base by protamine sulfate leads to proticles of only around 40 nm in diameter with otherwise unchanged properties. The availability of drug delivery systems of very similar composition but grossly different size may be advantageous when dealing with cells which show size-dependent particle uptake. These nanoparticles are promising candidates for ON delivery to cells because of the following reasons: (1) They are stable for several hours in solutions of up to physiological ionic strength; (2) they are efficiently taken up by cells; (3) after cellular uptake, they easily release the ONs even when these are present as phosphorothioates. 相似文献
67.
Anticipation of reward in a nonaversive differential conditioning paradigm and the brain reward system: an event-related fMRI study 总被引:1,自引:0,他引:1
Kirsch P Schienle A Stark R Sammer G Blecker C Walter B Ott U Burkart J Vaitl D 《NeuroImage》2003,20(2):1086-1095
Findings from animal as well as human neuroimaging studies suggest that reward delivery is associated with the activation of subcortical limbic and prefrontal brain regions, including the thalamus, the striatum, the anterior cingulate and the prefrontal cortex. The aim of the present study was to explore if these reward-sensitive regions are also activated during the anticipation of reinforcers that vary with regard to their motivational value. A differential conditioning paradigm was performed, with the presentation of a rewarded reaction time task serving as the unconditioned stimulus (US). Depending on their reaction time, subjects were given (or not given) a monetary reward, or were presented with a verbal feedback consisting of being fast or slow. In a third control condition no task needed to be executed. Each of the three conditions was introduced by a different visual cue (CS). Brain activation of 27 subjects was recorded using event-related functional magnetic resonance imaging. The results showed significant activation of the substantia nigra, thalamic, striatal, and orbitofrontal brain regions as well as of the insula and the anterior cingulate during the presentation of a CS signalling a rewarded task. The anticipation of a monetary reward produced stronger activation in these regions than the anticipation of positive verbal feedback. The results are interpreted as reflecting the motivation-dependent reactivity of the brain reward system with highly motivating stimuli (monetary reward) leading to a stronger activation than those less motivating ones (verbal reward). 相似文献
68.
Biochemical and clinical aspects of methotrexate neurotoxicity 总被引:6,自引:0,他引:6
Acute, subacute and chronic neurotoxicity have been observed after the administration of high-dose and/or intrathecal methotrexate (MTX). Acute toxicity is usually transient without permanent damage. Subacute and chronic toxicity are associated with changes in the brain and/or the spinal cord which may be progressive and even lead to coma and death in severe cases. It is believed that MTX can induce direct toxic effects to the CNS by damaging the neuronal tissue. Moreover, MTX interferes with the metabolic pathways of folates, excitatory amino acids, homocysteine, S-adenosylmethionine/S-adenosylhomocysteine, adenosine and biopterins, inducing biochemical alterations which have been associated with neurotoxic symptoms. It has been suggested that acute toxicity is partly mediated by adenosine, whereas homocysteine, S-adenosylmethionine/S-adenosylhomocysteine, excitatory amino acids and biopterins may play an important role in the development of subacute and chronic toxicity. A better understanding of the pathogenesis of MTX neurotoxicity would offer the possibility of developing new therapeutic strategies for its treatment or prevention. 相似文献
69.
J. S. Jacobsen K. Thorborg K. Søballe M. Ulrich‐Vinther 《Scandinavian journal of medicine & science in sports》2012,22(6):e140-e146
Symptomatic external snapping hip can be a long‐standing condition affecting physical function in younger people between 15–40 years. Gluteal weakness has been suggested to be associated with the condition. The aim of this study was to investigate whether eccentric hip abduction strength is decreased in patients with external snapping hip compared with healthy matched controls, and to examine isometric hip abduction, adduction, extension, flexion, internal rotation, and external rotation in patients with external snapping hip and matched controls. Thirteen patients with external snapping hip were compared with 13 healthy matched controls in a cross‐sectional study design. The mean age of the patients was 25.5 ± 3.4 years and the mean age of the controls was 25.6 ± 2.6 years. Eccentric and isometric strength were assessed with a handheld dynamometer, using reliable test procedures. Eccentric hip abduction strength was 16% lower in patients with external snapping hip compared with healthy matched controls (1.50 ± 0.47 Nm/kg versus 1.82 ± 0.48 Nm/kg, P = 0.01). No other strength differences were measured between patients and controls (P > 0.05). Eccentric hip abductor weakness was present in patients with symptomatic external snapping hip compared with healthy matched controls. 相似文献
70.
Evaluation of the effectiveness of a pathogen inactivation technology against clinically relevant transfusion‐transmitted bacterial strains 下载免费PDF全文