全文获取类型
收费全文 | 3903篇 |
免费 | 183篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 59篇 |
妇产科学 | 87篇 |
基础医学 | 411篇 |
口腔科学 | 61篇 |
临床医学 | 333篇 |
内科学 | 1186篇 |
皮肤病学 | 93篇 |
神经病学 | 252篇 |
特种医学 | 185篇 |
外科学 | 665篇 |
综合类 | 12篇 |
一般理论 | 1篇 |
预防医学 | 94篇 |
眼科学 | 58篇 |
药学 | 183篇 |
中国医学 | 3篇 |
肿瘤学 | 349篇 |
出版年
2023年 | 25篇 |
2022年 | 55篇 |
2021年 | 68篇 |
2020年 | 53篇 |
2019年 | 67篇 |
2018年 | 94篇 |
2017年 | 79篇 |
2016年 | 88篇 |
2015年 | 94篇 |
2014年 | 130篇 |
2013年 | 175篇 |
2012年 | 254篇 |
2011年 | 267篇 |
2010年 | 152篇 |
2009年 | 176篇 |
2008年 | 298篇 |
2007年 | 308篇 |
2006年 | 267篇 |
2005年 | 236篇 |
2004年 | 239篇 |
2003年 | 162篇 |
2002年 | 186篇 |
2001年 | 63篇 |
2000年 | 55篇 |
1999年 | 52篇 |
1998年 | 42篇 |
1997年 | 32篇 |
1996年 | 38篇 |
1995年 | 26篇 |
1994年 | 27篇 |
1993年 | 25篇 |
1992年 | 35篇 |
1991年 | 33篇 |
1990年 | 27篇 |
1989年 | 19篇 |
1988年 | 20篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 18篇 |
1983年 | 6篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1976年 | 4篇 |
1973年 | 5篇 |
1969年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有4129条查询结果,搜索用时 15 毫秒
1.
Alessia Scarselli Silvia Di Cesare Claudia Capponi Simona Cascioli Maria L. Romiti Gigliola Di Matteo Alessandra Simonetti Paolo Palma Andrea Finocchi Barbarella Lucarelli Rita M. Pinto Ippolita Rana Giuseppe Palumbo Maurizio Caniglia Paolo Rossi Rita Carsetti Caterina Cancrini Alessandro Aiuti 《Journal of clinical immunology》2015,35(4):373-383
2.
Spinal cord stimulation (SCS) is widely used for pain relief in patients with failed back surgery syndrome (FBSS), and muscle weakness is a common finding in patients with chronic pain. We present here a single case report of a 47‐year‐old woman, who, after SCS for FBSS, had continuous improvement in lower leg muscle strength and gait, but only transient and minimal pain relief. To the authors’ knowledge, this is only the second published case report of significant improvement in “motor” function, independent of the analgesic effect following SCS in FBSS. If SCS, in fact, does improve muscle strength, new strategies for the management of patients with chronic pain might be opened up. Further studies are needed to verify this hypothesis. 相似文献
3.
Giuseppe Lippi Gian Luca Salvagno Martina Montagnana Franco Manzato Gian Cesare Guidi 《Blood coagulation & fibrinolysis》2007,18(5):525-528
Preparation of blood specimens is a major bottleneck in the laboratory throughput. Reliable strategies for reducing the time required for specimen processing without affecting quality should be acknowledged, especially for laboratories performing stat analyses. The present investigation was planned to establish a minimal suitable centrifuge time for primary samples collected for routine coagulation testing. Five sequential primary vacuum tubes containing 0.109 mol/l buffered trisodium citrate were collected from 10 volunteers and were immediately centrifuged on a conventional centrifuge at 1500 x g, at room temperature for 1, 2, 5, 10 and 15 min, respectively. Hematological and routine coagulation testing, including prothrombin time, activated partial thromboplastin time and fibrinogen, were performed. The centrifugation time was inversely associated with residual blood cell elements in plasma, especially platelets. Statistically significant variations from the reference 15-min centrifuge specimens were observed for fibrinogen in samples centrifuged for 5 min at most and for the activated partial thromboplastin time in samples centrifuged for 2 min at most. Meaningful biases related to the desirable bias were observed for fibrinogen in samples centrifuged for 2 min at most, and for the activated partial thromboplastin time in samples centrifuged for 1 min at most. According to our experimental conditions, a 5-10 min centrifuge time at 1500 x g may be suitable for primary tubes collected for routine coagulation testing. 相似文献
4.
5.
Effects of androgen treatment in impotent men with normal and low levels of free testosterone 总被引:1,自引:0,他引:1
Cesare Carani M.D. Dante Zini M.D. Augusto Baldini M.D. Luciano Della Casa M.D. Anna Ghizzani M.D. Paolo Marrama M.D. 《Archives of sexual behavior》1990,19(3):223-234
The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimun serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens. 相似文献
6.
Total parenteral nutrition is now a broadly used method whose efficacy is confirmed, even if it is still not free from risk of complications. The Authors report their own clinical experience on 130 cases in the period 1981-1988. Complications were registered in 4.6% of the observed cases. They underline the problems relating to this subject. 相似文献
7.
Cesare M.N. Terracciano David Tweedie Kenneth T. MacLeod 《Pflügers Archiv : European journal of physiology》1997,433(4):540-542
. We have estimated sarcoplasmic reticulum calcium content using rapid application of caffeine on voltage clamped, isolated
guinea-pig ventricular myocytes. Caffeine induces the release of calcium from the sarcoplasmic reticulum and this calcium
is extruded from the cells by the sarcolemmal Na/Ca exchange. Integrating the inward Na/Ca exchange current thus allows estimations
of sarcoplasmic reticulum calcium content. Ventricular myocytes were stimulated to reach new steady-states by action potential
voltage clamps of varying duration. Once contractile steady-state had been reached caffeine was rapidly applied in place of
the next action potential and sarcoplasmic reticulum calcium content measured. Prolonging the action potential duration increased
sarcoplasmic reticulum calcium content and vice-versa. This calcium loading may underlie the positive inotropic effect of
increased action potential duration.
Received: 11 July 1996 / Received after revision: 15 October 1996 / Accepted: 26 November 1996 相似文献
8.
Mario R. Angi Maurizio Clementi Cristina Sardei Ettore Piattelli Cesare Bisantis 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1993,231(10):580-585
The existence of a visual feedback control of eye growth in humans is controversal, as the contributions of genetic and environmental factors are still unknown. To evaluate the heritability of refractive defects, we measured ocular refraction in 19 monozygote and 20 dizygote twin pairs (mean age 5 years). Monozygosity was ascertained by a common chorion, similarity of somatic traits, and identical dermatogliphes and was confirmed in myopes by blood marker diagnosis. Ocular refractive defects and axial length were evaluated by eye-loplegic autorefractometry and biometry. By comparing identical and fraternal twins heritability of refractive defects was estimated to be 0.08–0.14; this low value indicates that the observed variability in refractive errors is nongenetic in origin. Three monozygote pairs were anisomyopic; differences between eyes in identical twins were related to the increased axial length of myopic eyes. In one eye, myopia was attributed to visual deprivation induced by a congenital cataract, while in five eyes it was correlated directly to the degree of astigmatic defects. The discordant axial length observed in monozygote twins is nongenetic. In agreement with previous findings reported in the literature, it is proposed that visual impoverishment of retinal images may play an early regulatory role in postnatal eye growth.Deceased 相似文献
9.
M Rengo V Terrinoni G Galati A De Cesare A Martinazzoli E Fiori M Borghese A Florio 《Minerva chirurgica》1990,45(7):469-476
Underlining the importance of Profundus Femoral Artery and its capacity to make up for lower limb's haemodynamics during obliterative arteriopathy, the Authors conceive a funnel-shaped intravascular prosthesis, Goretex constructed (PTFE), to introduce, in case of obstruction, in the artery lumen with a suitable instrument. The research is performed through ten oldster dogs whose average weight is twenty-four kilograms. Isolated the deep Femoral Artery and carried out an arteriotomy of about two centimetres on the Common Femoral Artery, we bring the prothesis in Profundis Femoral Artery and we fix it to the wall of the Common Femoral Artery with 8/O microsurgical dots. After thirty days, the arteriographic test shows the patency of the endoprosthesis with normal peripheral flow in nine animals out of ten. By virtue of this preliminary experiment, the Authors point out the semplicity of this intervention, also feasible in local anaesthesia, the good tolerability of the prosthesis and its perfect integration with the surrounding arterious wall, without shifts or dissecting laminar flows between the external prosthesis wall and the vessel lumen of the animal. 相似文献
10.
Regional gene therapy for full-thickness articular cartilage lesions using naked DNA with a collagen matrix. 总被引:3,自引:0,他引:3
Paul E Di Cesare Sally R Frenkel Cathy S Carlson Carrie Fang Chuanju Liu 《Journal of orthopaedic research》2006,24(5):1118-1127
A novel gene therapy approach for treating damaged cartilage is proposed that involves placing endotoxin-free cDNA containing the gene for bone morphogenetic protein-2 (BMP-2) in type I collagen sponges and then transferring the naked plasmid DNA construct to the injury site. A full-thickness cartilaginous defect in rabbits implanted with plasmid containing a marker gene (beta-galactosidase) showed expressed protein as detected by immunostaining. At 1 week postimplantation, mesenchymal cells subjacent to the defect had incorporated the implanted naked plasmid DNA and, once transfected, served as local bioreactors, transiently producing the gene product. Plasmids containing the gene for BMP-2 implanted in collagen sponges in cartilage lesions stimulated hyalinelike articular cartilage repair at 12 weeks postimplantation, nearly equivalent in quality to that induced by collagen sponges with recombinant BMP-2 protein. Our approach circumvents the risks of inflammation and immunogenic response associated with the use of viral vectors. Naked plasmid DNA as a vehicle for transferring therapeutic genes has been shown to be effective in a therapeutic model within rabbit articular cartilage and appears to be safe and cost effective. 相似文献