全文获取类型
收费全文 | 7796篇 |
免费 | 820篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 223篇 |
妇产科学 | 241篇 |
基础医学 | 1066篇 |
口腔科学 | 171篇 |
临床医学 | 1011篇 |
内科学 | 1352篇 |
皮肤病学 | 108篇 |
神经病学 | 569篇 |
特种医学 | 503篇 |
外科学 | 910篇 |
综合类 | 374篇 |
一般理论 | 2篇 |
预防医学 | 844篇 |
眼科学 | 184篇 |
药学 | 510篇 |
2篇 | |
中国医学 | 179篇 |
肿瘤学 | 367篇 |
出版年
2022年 | 56篇 |
2021年 | 128篇 |
2020年 | 81篇 |
2019年 | 76篇 |
2018年 | 114篇 |
2017年 | 89篇 |
2016年 | 87篇 |
2015年 | 108篇 |
2014年 | 156篇 |
2013年 | 245篇 |
2012年 | 311篇 |
2011年 | 341篇 |
2010年 | 224篇 |
2009年 | 227篇 |
2008年 | 262篇 |
2007年 | 323篇 |
2006年 | 337篇 |
2005年 | 316篇 |
2004年 | 272篇 |
2003年 | 280篇 |
2002年 | 269篇 |
2001年 | 275篇 |
2000年 | 250篇 |
1999年 | 266篇 |
1998年 | 173篇 |
1997年 | 157篇 |
1996年 | 149篇 |
1995年 | 166篇 |
1994年 | 110篇 |
1993年 | 134篇 |
1992年 | 181篇 |
1991年 | 171篇 |
1990年 | 155篇 |
1989年 | 182篇 |
1988年 | 176篇 |
1987年 | 170篇 |
1986年 | 136篇 |
1985年 | 142篇 |
1984年 | 106篇 |
1983年 | 90篇 |
1982年 | 61篇 |
1981年 | 62篇 |
1980年 | 71篇 |
1979年 | 62篇 |
1978年 | 80篇 |
1977年 | 59篇 |
1976年 | 55篇 |
1972年 | 55篇 |
1971年 | 45篇 |
1955年 | 43篇 |
排序方式: 共有8668条查询结果,搜索用时 31 毫秒
101.
Horwood E Dowson H Gupta R Kaczmarski R Williamson M 《Journal of clinical pathology》2003,56(2):154-156
This report describes a case of myelofibrosis presenting as spinal cord compression on account of extramedullary haemopoietic tissue encroaching upon the spinal cord from a large pelvic mass. 相似文献
102.
Immunogenicity of recombinant protective antigen and efficacy against aerosol challenge with anthrax
Williamson ED Hodgson I Walker NJ Topping AW Duchars MG Mott JM Estep J Lebutt C Flick-Smith HC Jones HE Li H Quinn CP 《Infection and immunity》2005,73(9):5978-5987
Immunization with a recombinant form of the protective antigen (rPA) from Bacillus anthracis has been carried out with rhesus macaques. Rhesus macaques immunized with 25 mug or more of B. subtilis-expressed rPA bound to alhydrogel had a significantly increased immunoglobulin G (IgG) response to rPA compared with macaques receiving the existing licensed vaccine from the United Kingdom (anthrax vaccine precipitated [AVP]), although the isotype profile was unchanged, with bias towards the IgG1 and IgG2 subclasses. Immune macaque sera from all immunized groups contained toxin-neutralizing antibody and recognized all the domains of PA. While the recognition of the N terminus of PA (domains 1 to 3) was predominant in macaques immunized with the existing vaccines (AVP and the U.S. vaccine anthrax vaccine adsorbed), macaques immunized with rPA recognized the N- and C-terminal domains of PA. Antiserum derived from immunized macaques protected macrophages in vitro against the cytotoxic effects of lethal toxin. Passive transfer of IgG purified from immune macaque serum into naive A/J mice conferred protection against challenge with B. anthracis in a dose-related manner. The protection conferred by passive transfer of 500 mug macaque IgG correlated significantly (P = 0.003; r = 0.4) with the titers of neutralizing antibody in donor macaques. Subsequently, a separate group of rhesus macaques immunized with 50 mug of Escherichia coli-derived rPA adsorbed to alhydrogel was fully protected against a target dose of 200 50% lethal doses of aerosolized B. anthracis. These data provide some preliminary evidence for the existence of immune correlates of protection against anthrax infection in rhesus macaques immunized with rPA. 相似文献
103.
Metabolic effects of glucagon in the perfused rat heart 总被引:1,自引:0,他引:1
104.
105.
Horne G; Jamaludin A; Critchlow JD; Falconer DA; Newman MC; Oghoetuoma J; Pease EH; Lieberman BA 《Human reproduction (Oxford, England)》1998,13(11):3045-3048
Insemination with donor spermatozoa is an integral part of infertility
treatment. For the last 3 years in our unit, intrauterine insemination with
donor spermatozoa (IUID) has been used in preference to vaginal
insemination. In this retrospective study, patients were offered an initial
course of five single intrauterine inseminations with cryopreserved donor
spermatozoa and treatment was then reviewed. A total of 389 patients
received 1465 inseminations. In all, 1119 cycles were monitored using
luteinizing hormone serum analyses and 346 cycles using the urine home test
kits. The clinical pregnancy rate per insemination for the cycles monitored
by the serum assay was 18.0% (202/1119) compared with the urine cycles
(13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly
different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles
respectively). The viable clinical pregnancy rate was significantly higher
(P <03) for the serum cycles than for the cycles using the urinary
monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles
monitored by serum assay had a significantly higher cumulative viable
clinical pregnancy rate (P <0001) of 70.2% after nine inseminations
compared with the urine monitored cycles of 54.8%. The majority of patients
opted for the serum cycles, with a minority self-selecting the urine cycles
mainly for travelling convenience. The explanation for the significant
differences between the viable clinical pregnancy rates per insemination
and the cumulative viable clinical pregnancy rates may be due to the
sensitivity of the urine home test kit or the patients' interpretation of
the result.
相似文献
106.
107.
Pathophysiologic concentrations of lysophosphoglycerides quantified by electron microscopic autoradiography 总被引:5,自引:0,他引:5
J E Saffitz P B Corr B I Lee R W Gross E K Williamson B E Sobel 《Laboratory investigation; a journal of technical methods and pathology》1984,50(3):278-286
Lysophosphoglycerides accumulate in ischemic myocardium and appear to contribute to malignant dysrhythmia. Exposure of normoxic isolated Purkinje fibers or ventricular muscle strips to exogenous lysophosphatidyl choline (LPC) results in rapid, yet reversible, electrophysiologic derangements analogous to changes associated with ischemia in vivo. However, subcellular, local concentrations required for induction of electrophysiologic effects have not yet been elucidated unambiguously. The present study was designed to delineate the subcellular distribution and the sarcolemmal concentration of LPC by quantitative electron microscopic autoradiography after exposure of canine ventricular muscle strips to 3H-methyl LPC (200 microM) for 10 minutes. Tissue was processed for electron microscopy with a new procedure developed specifically to spatially fix choline phosphatides and render them insoluble in lipid solvents. Grain distributions were analyzed in the same group of cells that had been monitored electrophysiologically while superfused with LPC. LPC significantly decreased the resting membrane potential, action potential amplitude, duration, Vmax of phase 0, and conduction time. Grains were concentrated in the membranous organelles of cardiac myocytes. Myocyte sarcolemma exhibited the highest grain density (129 grains/100 micron2 versus a background of 0.27 grains/100 micron2). Calculations based on grain densities, emulsion sensitivity, exposure time, and specific activity indicated that the sarcolemma incorporated 5.4 X 10(6) LPC molecules/micron3 of membrane volume corresponding to approximately 1% of total sarcolemmal phospholipid. Since incorporation of only this small amount of lysophosphoglyceride into the sarcolemma was sufficient to elicit electrophysiologic disturbances, the observed accumulation of lysophosphoglycerides induced by ischemia appears to be sufficient to contribute to malignant dysrhythmia in vivo. 相似文献
108.
AIMS: It has been postulated that the recent world-wide increase in the incidence of non-Hodgkin's lymphoma (NHL) may have been caused by human infection with simian virus 40 (SV40) (a lymphotropic monkey virus that was introduced to man from contaminated poliovirus vaccines between 1955 and 1963); therefore, we set out to determine the incidence of SV40 DNA positivity in lymphoma samples from patients in Tasmania, Australia. METHODS: One hundred lymph node samples, 50 from patients with lymphomas and 50 from controls, were tested using PCR amplification of three SV40-specific primer pairs followed by dot-blot hybridisation. RESULTS: All of the samples tested contained amplifiable DNA, but none contained amplifiable SV40 sequences with any of the primer sets used. CONCLUSIONS: Our results demonstrate absence of SV40 in the lymphoid tissues of our study population in Tasmania, Australia. SV40 does not explain the increasing incidence of NHL in our population. 相似文献
109.
Chiu-Tsao ST Duckworth TL Hsiung CY Li Z Williamson J Patel NS Harrison LB 《Medical physics》2003,30(7):1732-1735
Many new models of 125I seeds are being introduced, mainly due to the increase in prostate seed implants. We have evaluated the SourceTech Medical (STM), model STM1251, 125I seed using thermoluminescent dosimeters (TLDs) in a solid water phantom. TLD cubes, LiF TLD-100, with dimension 1 mm on each edge, were irradiated at various distances, 1, 2, 3, and 5 cm, at angles ranging from 0 degrees to 90 degrees in 10 degrees increments. Sensitivity calibration of the TLDs was achieved by irradiation to 10 cGy with 6 MV x rays from a clinical linear accelerator, Clinac 600C. Concurrent with the 125I seed exposures, several TLDs were also exposed to 10 cGy with the 600C as a control set. Dose rates per unit air kerma strength were determined based on the 1999 NIST traceable standard for the STM1251 seed. They are presented as a function of distance r and angle theta. The TG-43 parameters, including the dose rate constant, lambda, anisotropy function, F(r,theta), radial dose function, g(r), anisotropy factor, phian(r), and anisotropy constant, phi, were obtained for use in radiation treatment planning software. The value of lambda was determined as 1.07 +/- 5.5% cGy U(-1) h(-1), which is comparable to model 6702 and to the value determined using the point extrapolation method by Kirov and Williamson. We also find agreement between our TLD data and their Monte Carlo results for g(r), F(r,theta), phian(r), and phi. Additionally, agreement is found with the TLD data of Li and Williamson for lambda and g(r). 相似文献
110.
Nisselle AE Delatycki MB Collins V Metcalfe S Aitken MA du Sart D Halliday J Macciocca I Wakefield A Hill V Gason A Warner B Calabro V Williamson R Allen KJ 《Clinical genetics》2004,65(5):358-367
There is debate as to whether community genetic screening for the mutation(s) causing hereditary hemochromatosis (HH) should be implemented, due to issues including disease penetrance, health economic outcomes, and concerns about community acceptance. Hemochromatosis is a common preventable iron overload disease, due in over 90% of cases to C282Y homozygosity in the HFE gene. We are, therefore, piloting C282Y screening to assess understanding of genetic information and screening acceptability in the workplace setting. In this program, HaemScreen, education was by oral or video presentation in a group setting. C282Y status was assessed by polymerase chain reaction (PCR) and melt-curve analysis on DNA obtained by cheek-brush sampling. Of eligible participants, 5.8% (1.5-15.8%) attended information and screening sessions, of whom 97.7% (5571 individuals) chose to be tested. Twenty-two C282Y (1 : 253) homozygotes were identified and offered clinical follow-up. There were 638 heterozygotes (1 : 8.7). The determinants for participation have been analyzed in terms of the principles outlined in the Health Belief Model. Widespread screening for HH is readily accepted in a workplace setting, and a one-to-many education program is effective. The level of participation varies greatly and the advertizing and session logistics should be adapted to the specific features of each workplace. 相似文献