全文获取类型
收费全文 | 3480篇 |
免费 | 72篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 90篇 |
妇产科学 | 178篇 |
基础医学 | 672篇 |
口腔科学 | 58篇 |
临床医学 | 388篇 |
内科学 | 394篇 |
皮肤病学 | 79篇 |
神经病学 | 98篇 |
特种医学 | 198篇 |
外科学 | 522篇 |
综合类 | 38篇 |
预防医学 | 272篇 |
眼科学 | 74篇 |
药学 | 292篇 |
中国医学 | 2篇 |
肿瘤学 | 187篇 |
出版年
2022年 | 32篇 |
2021年 | 46篇 |
2019年 | 30篇 |
2018年 | 33篇 |
2017年 | 26篇 |
2016年 | 39篇 |
2015年 | 35篇 |
2014年 | 46篇 |
2013年 | 58篇 |
2012年 | 80篇 |
2011年 | 141篇 |
2010年 | 85篇 |
2009年 | 61篇 |
2008年 | 103篇 |
2007年 | 131篇 |
2006年 | 135篇 |
2005年 | 127篇 |
2004年 | 105篇 |
2003年 | 88篇 |
2002年 | 71篇 |
2001年 | 74篇 |
2000年 | 105篇 |
1999年 | 85篇 |
1998年 | 54篇 |
1997年 | 37篇 |
1995年 | 28篇 |
1992年 | 72篇 |
1991年 | 109篇 |
1990年 | 115篇 |
1989年 | 120篇 |
1988年 | 106篇 |
1987年 | 124篇 |
1986年 | 110篇 |
1985年 | 99篇 |
1984年 | 69篇 |
1983年 | 55篇 |
1982年 | 25篇 |
1981年 | 28篇 |
1979年 | 47篇 |
1977年 | 36篇 |
1976年 | 39篇 |
1975年 | 48篇 |
1974年 | 69篇 |
1973年 | 51篇 |
1972年 | 48篇 |
1971年 | 40篇 |
1970年 | 45篇 |
1969年 | 34篇 |
1968年 | 28篇 |
1967年 | 24篇 |
排序方式: 共有3570条查询结果,搜索用时 15 毫秒
81.
82.
Stefana Sabtcheva Ivan N. Ivanov Bozhana Todorova Yordan Simeonov Elina Dobreva Krasimira Ivanova 《Journal of chemotherapy (Florence, Italy)》2016,28(5):450-453
We report the identification of OXA-48-producing Klebsiella pneumoniae, causing peritonitis in a cancer patient admitted to the Oncology Hospital in Sofia. The isolate had reduced susceptibility to carbapenems but remained susceptible to extended-spectrum cephalosporins. PCR and sequencing confirmed the presence of blaOXA-48 gene flanked by two intact copies of IS1999 on truncated ΔTn1999.1. This transposon was located on unusual non-typeable 29-kb plasmid that could be transferred only by transformation. Multilocus sequence typing (MLST) indicated the presence of the sequence type ST530.This is the first documented infection due to OXA-48-producing Enterobacteriaceae strain in Bulgaria. 相似文献
83.
Victor Yevseyevich Radzinsky Igor Isaakovich Ivanov Marina Borisovna Khamoshina Igor Nikolaevich Kostin Elena Varlamovna Kavteladze 《Gynecological endocrinology》2019,35(7):27-30
AbstractEndometriosis is currently considered as one of the most common diseases associated with infertility. A controversial issue is whether endometriosis per se exerts a detrimental effect on IVF outcomes. Failure of implantation due to endometriosis-associated infertility is a contradictory and widely discussed burden nowadays. The purpose of the study is to assess the quality of embryos and implantation rate in women with infertility associated with endometriosis. The study included infertile reproductive aged women, between 26 and 40 years who underwent IVF and ICSI procedures. The patients were divided into two groups: group I (n?=?70) involved 70 patients with recurrent unilateral endometriomas, II control group (n?=?50) with tubal factor infertility. The quality of the retrieved embryos was assessed according to the generally accepted classification of Gardner, indicating the rate of implantation in each group. Embryo transfer was performed in case of high quality embryos. Assessing the ovarian reserve indicators, in the group I patients with recurrent unilateral endometriomas the serum level of AMH was significantly lower (2.1?±?1.75 vs. 3.2?±?1.4, p?<?.005), as well as the number of retrieved oocytes (8.1?±?3.9 and 10.1?±?6.8, p?<?.005). The analysis of the results demonstrated that the duration of stimulation in the group patients with recurrent unilateral endometriomas was significantly higher in comparison with the group II (12.2?±?1.8 and 10.2?±?1.6 days, p?<?.001). Nevertheless, the number of good quality embryos retrieved was comparable in both groups (2.2?±?1.5 and 2.8?±?1.8). In the group I patients with recurrent unilateral endometriomas, there was a statistically significant decrease of implantation rate (17.1% vs. 24% p?<?.005). The results of the study revealed no statistical difference in embryo quality in the study cohort. However, it is important to note that a statistically significant difference in implantation rate in the group of endometriosis-associated infertility compared was obtained 1.5 times lower than in the control group (15.8% vs. 24.0% p?<?.005). The achieved results demonstrated an adverse IVF outcome in infertile women with recurrent endometrioma compared to the control group. 相似文献
84.
85.
86.
87.
88.
An enzyme-linked immunosorbent assay has been developed for the quantitation of activated Hageman factor-C1 inactivator (HF-C1 INH) complexes. Addition of increasing quantities of either of the major forms of activated Hageman factor (HFa or HFf) to normal plasma or to Hageman factor-deficient plasma leads to a dose-dependent increase in activated HF-C1 INH complexes. As little as 0.5 micrograms/mL of activated HF added to plasma can be detected, corresponding to activation of approximately 2% of plasma HF. The sensitivity of the assay is increased at least tenfold when complexes are formed in HF- deficient plasma, indicating competition between unactivated HF and activated HF-C1 INH complexes for binding to the antibody. Specificity is demonstrated in that addition of activated HF to hereditary angioedema plasma yields less than 1% of the activated HF-C1 INH complex formation obtained with normal plasma. Kaolin activation of HF- deficient plasma yields no detectable complex formation. Kaolin activation of prekallikrein-deficient plasma demonstrates a time- dependent increase in formation of activated HF-C1 INH complex consistent with the ability of HF in this plasma to autoactivate as the time of incubation with the surface is increased. Kaolin treatment of high-molecular weight (HMW) kininogen-deficient plasma yields an even more profound abnormality in the rate of formation of activated HF-C1 INH complexes reflecting the complex role of HMW kininogen in the initiation of contact activation. Although addition of corn inhibitor to plasma prevents activated HF-C1 INH complex formation, it does not inhibit activated HF sufficiently fast to prevent prekallikrein activation. 相似文献
89.
High-dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation as a treatment option in multiple sclerosis 总被引:1,自引:0,他引:1
Shevchenko YL Novik AA Kuznetsov AN Afanasiev BV Lisukov IA Kozlov VA Rykavicin OA Ionova TI Melnichenko VY Fedorenko DA Kulagin AD Shamanski SV Ivanov RA Gorodokin G 《Experimental hematology》2008,36(8):922-928
High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic stem cell transplantation (auto-HSCT) is a new and promising approach to the treatment of multiple sclerosis (MS) patients because currently there are no effective treatment methods for this disease. In this article, we present results of a prospective clinical study of efficacy of HDIT + auto-HSCT in MS patients. The following treatment strategies were employed in the study: "early," "conventional," and "salvage/late" transplantation. Fifty patients with various types of MS were included in this study. No toxic deaths were reported among 50 MS patients; transplantation procedure was well-tolerated by the patients. The efficacy analysis was performed in 45 patients. Twenty-eight patients achieved an objective improvement of neurological symptoms, defined as at least 0.5-point decrease in the Expanded Disability Status Scale (EDSS) score as compared to the baseline and confirmed during 6 months, and 17 patients had disease stabilization (steady EDSS level as compared to the baseline and confirmed during 6 months). The progression-free survival at 6 years after HDIT + auto-HSCT was 72%. Magnetic resonance imaging data were available in 37 patients before transplantation showing disease activity in 43.3%. No active, new, or enlarging lesions were registered in patients without disease progression. In conclusion, HDIT + auto-HSCT suggests positive results in management of patients with different types of MS. Identification of treatment strategies based on the level of disability, namely "early," "conventional," and "salvage/late" transplantation, appears to be feasible to improve treatment outcomes. 相似文献
90.
Warkentin TE; Hayward CP; Boshkov LK; Santos AV; Sheppard JA; Bode AP; Kelton JG 《Blood》1994,84(11):3691-3699
Heparin-induced thrombocytopenia is characterized by moderate thrombocytopenia and thrombotic complications, whereas quinine/quinidine-induced thrombocytopenia usually presents with severe thrombocytopenia and bleeding. Using flow cytometry and assays of procoagulant activity, we investigated whether sera from patients with these immune drug reactions could stimulate normal platelets to generate platelet-derived microparticles with procoagulant activity. Sera or purified IgG from patients with heparin-induced thrombocytopenia stimulated the formation of platelet-derived microparticles in a heparin-dependent fashion. Further studies showed that heparin-induced thrombocytopenia sera also produced a marked increase in procoagulant activity. In contrast, sera from patients with quinine- or quinidine-induced thrombocytopenia did not generate platelet-derived microparticles nor generate increased procoagulant activity. However, quinine/quinidine-induced thrombocytopenia sera produced a significant increase in the binding of IgG to platelets in a drug-dependent fashion, whereas sera from patients with heparin-induced thrombocytopenia demonstrated no drug-dependent binding of IgG to platelets. We also observed increased levels of circulating microparticles in patients with acute heparin-induced thrombocytopenia compared with control patients. Our observations indicate that the generation of procoagulant platelet-derived microparticles in vivo is a plausible explanation for the thrombotic complications observed in some patients with heparin-induced thrombocytopenia. 相似文献