全文获取类型
收费全文 | 5842篇 |
免费 | 703篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 104篇 |
妇产科学 | 110篇 |
基础医学 | 895篇 |
口腔科学 | 210篇 |
临床医学 | 868篇 |
内科学 | 538篇 |
皮肤病学 | 60篇 |
神经病学 | 510篇 |
特种医学 | 142篇 |
外科学 | 705篇 |
综合类 | 603篇 |
预防医学 | 755篇 |
眼科学 | 87篇 |
药学 | 538篇 |
27篇 | |
中国医学 | 229篇 |
肿瘤学 | 203篇 |
出版年
2024年 | 30篇 |
2023年 | 158篇 |
2022年 | 304篇 |
2021年 | 344篇 |
2020年 | 346篇 |
2019年 | 305篇 |
2018年 | 319篇 |
2017年 | 298篇 |
2016年 | 219篇 |
2015年 | 199篇 |
2014年 | 322篇 |
2013年 | 476篇 |
2012年 | 283篇 |
2011年 | 287篇 |
2010年 | 230篇 |
2009年 | 237篇 |
2008年 | 230篇 |
2007年 | 231篇 |
2006年 | 208篇 |
2005年 | 192篇 |
2004年 | 155篇 |
2003年 | 137篇 |
2002年 | 120篇 |
2001年 | 76篇 |
2000年 | 57篇 |
1999年 | 54篇 |
1998年 | 52篇 |
1997年 | 62篇 |
1996年 | 50篇 |
1995年 | 52篇 |
1994年 | 51篇 |
1993年 | 45篇 |
1992年 | 44篇 |
1991年 | 40篇 |
1990年 | 38篇 |
1989年 | 22篇 |
1988年 | 23篇 |
1987年 | 25篇 |
1986年 | 28篇 |
1985年 | 53篇 |
1984年 | 56篇 |
1983年 | 39篇 |
1982年 | 44篇 |
1981年 | 46篇 |
1980年 | 24篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 2篇 |
排序方式: 共有6654条查询结果,搜索用时 15 毫秒
21.
Malignant mixed Müllerian tumor is a rare neoplasm that occurs most frequently in elderly patients. It is characterized by a mixture of malignant epithelial and sarcomatous components. Little has been published about Papanicolaou smear findings pertaining to malignant mixed Müllerian tumors. We present our experience, with an emphasis on cytologic detail. Nine patients (median age, 65 yr) met our study criteria. All available smears and surgical specimens were reviewed. Four smears were positive for malignancy, with a sensitivity of 44% (3 adenocarcinoma, and 1 squamous-cell carcinoma, small-cell type). The results of our study showed that Papanicolaou smear findings pertaining to malignant mixed Müllerian tumors are seen in patients with advanced-stage disease with involvement of the lower uterine segment or cervix. The usual finding is large numbers of high-grade epithelial malignant cells in a necrotic background. The mesenchymal component rarely sheds cells visible on Papanicolaou smear. 相似文献
22.
Pavlik LL Bezgina EN Dzeban DA Moshkov DA 《Neuroscience and behavioral physiology》2005,35(5):453-456
The pyroantimonate method was used to study the distribution of calcium ions in the mixed synapses of Mauthner neurons after exposure to substances altering the electrotonic conductivity of these synapses mediated by gap junctions (GJ). Ecdysone, an agent which increases GJ conductivity, produced precipitates of calcium pyroantimonate coating the whole postsynaptic surface of the GJ area, making them strongly asymmetrical. Precipitate granules were also seen to appear in the clefts of desmosome-like contacts (DLC). Chlorpromazine, which decreases GJ conductivity, produced precipitates in GJ clefts and on the pre- and postsynaptic membranes. No precipitate formed in DLC clefts. These results demonstrate that ecdysone acts as an agent selectively increasing GJ conductivity without affecting DLC function. Chlorpromazine had a double action, blocking conduction through both GJ and DLC. Thus, studies of agents altering GJ permeability require consideration of the possibility that they may interact with actin-containing structures also involved in the transport of the electrotonic signal.Translated from Morfologiya, Vol. 125, No. 3, pp. 32–35, May–June, 2004. 相似文献
23.
Animal or human blood protein is a costly but necessary additive to tissue culture. This supplemental protein is provided by the addition of pooled serum or heparinized plasma to standard tissue culture media. Many blood centers store CPDA-1 anticoagulated plasma, a form that does not provide optimal support of mixed lymphocyte culture (MLC). The optimal amount of CaCl2 (1 ml of 1 M CaCl2/100 g) added to citrate plasma and the use of glass vessels result in a completely clotted product that is comparable in MLC support to commercially available pooled human serum. Laboratories that have access to CPDA-1 plasma can replace the growing demand for serum with recalcified plasma without sacrificing quality. 相似文献
24.
Direct estimation of the frequency of human cytotoxic T lymphocytes and their precursors following in vitro allosensitization 总被引:2,自引:0,他引:2
Cell mediated lympholysis (CML) has been proposed as an in vitro model of the rejection process that results from transplantation of allogeneic tissue. To date, the absolute frequencies of cytotoxic T lymphocytes (CTL) and their precursors (CTL.P) have not been directly estimated in man because of technical difficulties. Through optimizing the conditions for radiometric detection of 51Cr release and the attendant improvement in CML sensitivity, direct CTL frequency estimates have been determined in peripheral blood (PBL), spleen (SPL), and lymph nodes (LNC) after in vitro allostimulation using unrelated human cells and limiting dilution assays. The mean frequency of CTL generated from PBL is 1 in 826 cells (0.121% +/- 0.101%) which, from preliminary experiments, is significantly greater than that generated from either LNC or SPL (p less than 0.05). With restimulation of primed cells on day 10, the frequency of CTL generated from PBL was increased 400%. The CTL.P frequency (0.0064% +/- 0.0050%) was approximately 5% of the corresponding CTL frequency. The CTL.P frequencies were found to be minimal estimates as both accessory "filler" cells and T cell growth factors increased the level of detection of CTL.P an average of threefold. The limiting cell dilution assay as detailed in this report should be a powerful tool for defining the cellular requirements and related factors necessary for optimal induction of a CTL response and should provide the means for determination of the immunogenetic requirements and the allospecificity of human cytotoxic lymphocytes. 相似文献
25.
Gordon B. Strom Richard N. Boswell Robert L. Jacobs 《The Journal of allergy and clinical immunology》1983,72(1):46-53
Thirty-four patients with a history of immediate hypersensitivity to the sting of the imported fire ant were evaluated in a study designed to compare the diagnostic usefulness of fire ant whole body extract (WBE) preparations with that of fire ant venom (IFAV). Ninety-one percent () of the hypersensitive patients skin tested with IFAV at a maximal concentration of 1:5 × 103, , demonstrated a wheat equal to or greater than the histamine control. Fifty-three percent () of the group were skin test positive to a WBE preparation. When the criteria for a positive skin test were relaxed, 82% of the hypersensitive group could be identified with the IFAWBE. A comparison of skin test results in sensitive patients revealed variability in the sensitivity of the WBE preparations utilized in the study. Leukocyte histamine release demonstrated a dose-response release of histamine with both IFAV and SIWBEa preparations. Specific venom antisera produced in rabbits identified a precipitin line of common identity in a gel-diffusion system containing IFAWBE and IFAV. This finding was verified by the competitive inhibition of IFAWBE with IFAV in a solid-phase radioimmunoassay system. Fire ant WBEs contain venom constituents and are effective diagnostic agents in up to 82% of patients with hypersensitivity to the sting of the imported fire ant. Marked variability in the responsiveness of sensitive patients to different WBE preparations mandates standardization of these diagnostic preparations. 相似文献
26.
《Diagnostic Histopathology》2023,29(9):424-426
Mixed tumour of the skin is a rare adnexal tumour of sweat gland origin, which can be benign or malignant. Histologically, it is defined by the presence of epithelial, myoepithelial and mesenchymal elements. The latter can take several forms, but both bone formation and cartilage formation are independently rare features. We present three rare cases of mixed tumour of the skin. Two of these displayed both mature bone and cartilaginous mesenchymal elements, while the third displayed mature bone formation without cartilage. 相似文献
27.
Abstract: There is evidence to indicate that opioid compounds with mixed μ agonist/δ antagonist properties are analgesics with low propensity to produce tolerance and physical dependence. A chimeric peptide containing the potent and selective μ agonist H‐Dmt‐D‐Arg‐Phe‐Lys‐NH2 ([Dmt1]DALDA) (Dmt = 2′,6′‐dimethyltyrosine) and the potent and selective δ antagonist H‐Tyr‐TicΨ[CH2‐NH]Cha‐Phe‐OH (TICP[Ψ]) (Cha = cyclohexylalanine), connected ‘tail‐to‐tail’ via a short linker, was synthesized using a combination of solid‐phase and solution techniques. The resulting peptide, H‐Dmt→D‐Arg→Phe→Lys‐NH‐CH2‐CH2‐NH‐Phe←Cha[NH‐CH2]ΨTic←Tyr‐H, showed the expected μ agonist/δ antagonist profile in the guinea‐pig ileum and mouse vas deferens assays. Its μ and δ receptor binding affinities were in the low nanomolar range, as determined in rat brain membrane binding assays. 相似文献
28.
Patients with xeroderma pigmentosum (XP) are highly sensitive to ultraviolet radiation and prone to develop multiple skin
malignancies. We report two children under 6 years of age with XP who each developed two histologically different types of
malignancies simultaneously. We conclude that it is of importance to be aware of the possibility of multiple malignancies
of different types, even in young children.
Accepted: 16 December 1996 相似文献
29.
An AB case design was used to examine the efficacy of virtual reality exposure therapy (VRET) in treating driving phobia. After a one week baseline, the patient received three treatment sessions over a ten day period. Treatment included practice of four VR driving scenarios. Peak anxiety decreased within and across sessions. Ratings of anxiety and avoidance declined from pre-treatment and post-treatment, with gains maintained at seven month followup. Phobia-related interference in daily functioning similarly decreased. The results suggest that it would be useful to further evaluate the efficacy of VRET for driving phobia in controlled clinical trials. 相似文献
30.
[目的]探讨当归六黄汤加减对混合痔术后盗汗的疗效。[方法]对32例混合痔术后盗汗患者采用当归六黄汤加减。[结果]治愈11例(占34·4%),显效16例(占50·0%),有效5例(占16·6%)。[结论]当归六黄汤能有效治疗混合痔术后盗汗。 相似文献