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141.
Permeation of human ovarian tissue with cryoprotective agents in preparation for cryopreservation 总被引:18,自引:10,他引:18
Newton H; Fisher J; Arnold JR; Pegg DE; Faddy MJ; Gosden RG 《Human reproduction (Oxford, England)》1998,13(2):376-380
The recent improvements in the treatment of cancer by chemo- and
radiotherapy have led to a significant increase in the survival rates of
patients with malignant disease, but at the expense of distressing side
effects. One major problem, especially for younger patients, is that
aggressive therapy destroys a significant proportion of the follicular
population, which can result in either temporary or permanent infertility.
Freeze-banking pieces of ovarian cortex prior to treatment is one strategy
for preserving fecundity. When the patient is in remission, fertility
could, theoretically, be restored by autografting the thawed tissue at the
orthotopic site or by growing isolated follicles to maturity in vitro.
Recent studies have found good follicular survival in frozen-thawed human
ovarian tissue but to optimize the process an effective cryopreservation
method needs to be developed. An essential part of such a technique is to
permeate the tissue with a cryoprotectant to minimize ice formation and the
extent of this equilibration is an important determinant of post-thaw
cellular survival. In the current study, we have investigated the diffusion
of four cryoprotective agents into human tissue at both 4 degrees C and 37
degrees C. We have also studied the effect of adding different
concentrations of the non penetrating cryoprotective agent, sucrose, to the
freezing media using the release of lactate dehydrogenase as a measure of
its protective effect. At 4 degrees C propylene glycol and glycerol
penetrated the tissue significantly slower than either ethylene glycol or
dimethyl sulphoxide. At the higher temperature of 37 degrees C all four
cryoprotectants penetrated at a faster rate, however concern about enhanced
toxicity prevents the use of these conditions in practice. Thus, the
results suggest that the best method of preparing tissue for freezing is
exposure for 30 min to 1.5 M solutions of ethylene glycol or dimethyl
sulphoxide at 4 degrees C; this achieved a mean tissue concentration that
was almost 80% that of the bathing solution. We also report that the
addition of low concentrations of sucrose to the freezing medium does not
have a significant protective effect against freezing injury.
相似文献
142.
Th. Schmeiser W. Heit R. Arnold D. Bunjes M. Wiesneth B. Hertenstein W. Hampl H. Heimpel 《Journal of molecular medicine (Berlin, Germany)》1987,65(20):967-974
Summary Conditioning therapy with aggressive chemotherapy and irradiation induces a state of transient combined immunodeficiency in bonemarrow transplant recipients. This promotes the occurrence of severe cytomegalovirus (CMV) infections, the most frequent lethal complication after bone-marrow transplantation (BMT) at present.Forty-four BMT recipients received CMV-IgG-hyperimmunoglobulin for CMV prophylaxis intravenously. The efficacy of this prophylaxis and possible risk factors for the occurrence of CMV-induced interstitial pneumonia (IP) were analyzed. Risk factors for the promotion of a CMV-IP were: additional immunosuppressive therapy after BMT, CMV-positive serostatus of the recipient, CMV-seropositive granulocyte transfusion, CMV infection immediately prior to BMT, and HLA-haploidentical BMT. In this study the incidence of graftversus-host disease was low and was not associated with the incidence of CMV infections. The use of T-cell-depleted grafts did not result in increased CMV infections or IP and may possibly have improved the immunological reconstitution.Abbreviations BMT
Bone-marrow transplantation
- CMV
Cytomegalovirus
- CMV-IG
CMV-IgG-hyperimmunoglobulin
- GvHD
Graft-versus-host disease
- IP
Interstitial pneumonia
- IS
Immunosuppressive therapy 相似文献
143.
Effects of Escherichia coli and Porphyromonas gingivalis lipopolysaccharide on pregnancy outcome in the golden hamster. 总被引:5,自引:0,他引:5 下载免费PDF全文
This report describes the effects of two gram-negative bacterial endotoxin (lipopolysaccharide [LPS]) preparations on hamster pregnancy outcome variables. Single intravenous challenges with Escherichia coli and Porphyromonas gingivalis LPS on day 8 of pregnancy produced dose-dependent effects on fetal weight malformation and fetal resorption with E. coli LPS having potent embryolethal effects. Premating maternal exposure to P. gingivalis produced embryolethal effects similar to those of E. coli. These data suggest that maternal exposure to P. gingivalis LPS prior to and during pregnancy can induce deleterious effects on the developing fetus. 相似文献
144.
Molecular mechanism for loss of visual cortical responsiveness following brief monocular deprivation
A dramatic form of experience-dependent synaptic plasticity is revealed in visual cortex when one eye is temporarily deprived of vision during early postnatal life. Monocular deprivation (MD) alters synaptic transmission such that cortical neurons cease to respond to stimulation of the deprived eye, but how this occurs is poorly understood. Here we show in rat visual cortex that brief MD sets in motion the same molecular and functional changes as the experimental model of homosynaptic long-term depression (LTD), and that prior synaptic depression by MD occludes subsequent induction of LTD. The mechanisms of LTD, about which there is now a detailed understanding, therefore contribute to visual cortical plasticity. 相似文献
145.
Angiogenic factors prepared from rat Walker 256 mammary carcinoma, (TAF) and activated mouse peritoneal macrophages (MAF), were tested for their ability to stimulate vascularization during healing. They were applied to one of a pair of bilaterally symmetrical, autologous, isotopic, full thickness skin grafts in mice. Blood flow to treated and untreated graft pairs was compared by their uptake of injected 86Rb Cl, at 3 and 7 days after grafting. No difference was detected after treatment with either agent. We conclude that while angiogenic factors are important in vascularization during healing, this normally occurs at a near maximal rate and cannot be further enhanced. 相似文献
146.
Daniel Hork Franti eksvec Jaroslav Klal Arnold A. Adamyan Yurii D. Volynskii Olga S. Voronkova Leonid S. Kokov Klara Z. Gumargalieva 《Biomaterials》1986,7(6):467-470
In this study we report the results of clinical experiments, obtained with spherical particles made from poly(2-hydroxyethyl methacrylate) used in the embolization of arteriovenous anastomoses, in the suppression of pulmonary haemorrhage and haemoptysis and in the occlusion of some other arteries. So far we have used these particles in the treatment of 187 patients. It must be stressed that the advantage of spherical particles consists in the simplicity of their introduction into the blood vessel through a catheter, while in the blood vessel itself the particle swells in blood still more, when compared with the particle size in saline. This results in an immediate and permanent haemostatic effect. No revascularization occurs. 相似文献
147.
Baujat G Rio M Rossignol S Sanlaville D Lyonnet S Le Merrer M Munnich A Gicquel C Colleaux L Cormier-Daire V 《American journal of medical genetics. Part C, Seminars in medical genetics》2005,(1):4-11
Here, we report the clinical and molecular analysis of 75 patients with overgrowth and mental retardation, including 45 previously reported cases [Rio et al., 2003; Baujat et al., 2004]. Two groups are distinguished: group I corresponding to patients with recognizable overgrowth syndromes (Sotos syndrome (SS), Weaver syndrome (WS), Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome (SGBS), and del(22)(qter) syndrome) (60 cases) and group II corresponding to unclassified cases (15 patients). We investigated NSD1 and GPC3 deletions or mutations, 11p15 abnormalities, and 22qter deletions. Surprisingly, in Group I, two SS patients had 11p15 abnormalities and two patients with Beckwith-Wiedemann syndrome had NSD1 aberrations. In group II, two cases of del(22)(qter) were identified but neither NSD1, 11p15, nor GPC3 abnormalities were detected. These results emphasize the clinical and molecular overlap in overgrowth conditions. 相似文献
148.
OBJECTIVE: To investigate the retraction time, forces, and torques applied to the football helmet during removal of the face mask with different face-mask removal tools. DESIGN AND SETTING: Subjects retracted the face mask of a football helmet mounted to a force platform in a laboratory setting. They removed a standard face mask by cutting or removing (or both) the lateral plastic loop straps using 4 different tools: the Trainer's Angel (TA), FM Extractor (FM), power screwdriver (SD), and Quick Release System (QR) in a counterbalanced fashion. SUBJECTS: Eighteen certified athletic trainers participated in this study. MEASUREMENTS: We started measuring time when the subject picked up the tool and ended when the face mask was in a fully retracted position. Maximum forces and torques were measured from the force platform during the retraction process. RESULTS: The SD and QR retracted the face mask significantly faster than the TA and FM. Forces producing superior-inferior translation were least with the SD. The SD and QR produced less lateral translation and rotation and lateral flexion moment than the TA and FM. The FM produced less torque in the lateral flexion moment than the TA. CONCLUSIONS: Tools that removed the loop straps (SD, QR) were faster and produced less force and torque on the helmet than the tools that cut through the loop straps (TA, FM). 相似文献
149.
Peripheral Tolerance as a Multi-Step Mechanism 总被引:10,自引:0,他引:10
Günter J. Hämmerling Günther Schönrich Iris Ferber Bernd Arnold 《Immunological reviews》1993,133(1):93-104
150.