全文获取类型
收费全文 | 1103篇 |
免费 | 60篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 14篇 |
妇产科学 | 94篇 |
基础医学 | 133篇 |
口腔科学 | 7篇 |
临床医学 | 74篇 |
内科学 | 263篇 |
皮肤病学 | 15篇 |
神经病学 | 102篇 |
特种医学 | 19篇 |
外科学 | 186篇 |
综合类 | 9篇 |
预防医学 | 57篇 |
眼科学 | 25篇 |
药学 | 66篇 |
中国医学 | 1篇 |
肿瘤学 | 87篇 |
出版年
2023年 | 13篇 |
2022年 | 31篇 |
2021年 | 34篇 |
2020年 | 8篇 |
2019年 | 18篇 |
2018年 | 33篇 |
2017年 | 27篇 |
2016年 | 18篇 |
2015年 | 33篇 |
2014年 | 26篇 |
2013年 | 48篇 |
2012年 | 55篇 |
2011年 | 68篇 |
2010年 | 40篇 |
2009年 | 34篇 |
2008年 | 67篇 |
2007年 | 36篇 |
2006年 | 37篇 |
2005年 | 43篇 |
2004年 | 44篇 |
2003年 | 43篇 |
2002年 | 38篇 |
2001年 | 22篇 |
2000年 | 25篇 |
1999年 | 15篇 |
1998年 | 10篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 23篇 |
1991年 | 18篇 |
1990年 | 26篇 |
1989年 | 23篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 25篇 |
1985年 | 20篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1972年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有1165条查询结果,搜索用时 375 毫秒
1.
2.
Linus Okeke Odunayo Ikuerowo Ifeanyi Chiekwe Blessing Etukakpan Olayiwola Shittu Olubunmi Olapade-Olaopa 《International journal of urology》2007,14(8):729-732
OBJECTIVE: Varicocele is the most common treatable cause of male infertility and is associated with progressive decline in testicular function. Varicocelectomy, a commonly performed operation, is indicated in infertile males with varicoceles who have oligospermia, asthenospermia, teratospermia or a combination of these factors. It is not clear if varicocelectomy is indicated if the patients have normal sperm density associated with asthenospermia or teratospermia. METHODS: We reviewed 167 patients with varicocele-associated male infertility over a 7-year period (December 1999-November 2005). Pre- and post-varicocelectomy seminal fluid analyses, assessed using the World Health Organization criteria, were obtained at intervals of 4-6 months. Wilcoxon signed rank tests were used to evaluate for statistical significance and P < or = 0.05 was considered significant. RESULTS: The mean age of the patients and their spouses were 35 and 28 years, respectively. The mean duration of infertility was 3.2 years (range, 1.5-7.5). Oligospermia, teratospermia, asthenospermia, oligospermia, asthenospermia and teratospermia (OAT) syndrome and azoospermia were found preoperatively in 106 (63.5%), 58 (34.7%), 154 (92%), 118 (71%) and 15 (9%) patients, respectively. Overall, significant improvements in semen volume (P < 0.001), sperm density (P < 0.001), sperm motility (P < 0.001) and sperm vitality (P < 0.001) were obtained after varicocelectomy. There was, however, no significant improvement in sperm morphology after varicocelectomy (P = 0.220). When patients with preoperative oligospermia (sperm density, <20 million/mL) were considered separately, varicocelectomy led to significant improvement in all the semen parameters except the sperm morphology (P = 0.183). Conversely, when varicocele patients with a sperm density of > or =20 million/mL (normospermia) associated with asthenospermia and/or teratospermia were considered separately, they did not show significant improvement in any of the semen parameters after varicocelectomy (P > 0.05). In addition, azoospermic patients did not show significant improvement in any of the semen parameters (P > 0.05) CONCLUSION: No significant improvement in semen parameters may be obtained in patients with clinical varicocele and preoperative normospermia. It is possible that only patients with preoperative oligospermia may benefit from varicocelectomy. Larger multi-institutional studies are needed to determine more definitively if asthenospermia or teratospermia in normospermic subfertile males with clinical varicoceles are in fact indications for varicocelectomy. 相似文献
3.
S. Spellerberg P. Reimer G. Blessing H.H. Coenen S.M. Qaim 《Applied radiation and isotopes》1998,49(12):611
55Co and 57Co were produced via (p, α) and (p, 2p) reactions, respectively, on highly enriched 58Ni. Thin deposits of 58Ni on Cu backing, obtained electrolytically, were irradiated using a slanting beam. The separation of radiocobalt and the recovery of the enriched target material were effected via anion-exchange chromatography. 相似文献
4.
H B Muss J A Blessing P Hanjani J H Malfetano G M Kemp K Webster 《American journal of clinical oncology》1992,15(4):363-364
Eighteen evaluable patients with recurrent or metastatic nonsquamous carcinoma of the uterine cervix were treated with 1,500 micrograms/m2 of echinomycin every 4 weeks. Seven patients had received prior chemotherapy. There was one complete response (5.6%), 95% confidence interval for response of 0-27%. The major toxicity was nausea and vomiting, which was moderate to severe in eight patients. Myelosuppression was minimal. Echinomycin in this dose and schedule displays minimal activity in patients with advanced nonsquamous carcinoma of the cervix. 相似文献
5.
Dr Jonas Hähnel MD Wolfgang Friesdorf MD Bernhard Schwilk MD Thomas Marx MD Silvia Blessing 《Journal of clinical monitoring and computing》1992,8(1):1-6
The technical equipment of today's intensive care unit (ICU) workstation has been characterized by a gradual, incremental accumulation of individual devices, whose presence is dictated by patient needs. These devices usually present differently designed controls, operate under different alarm philosophies, and cannot communicate with each other. By contrast, ICU workstations could be equipped permanently and in a standardized manner with electronically linked modules if the attending physicians could reliably predict, at the time of admission, the patient's equipment needs. Over a period of 3 1/2 months, the doctors working in our 20-bed surgical ICU made 1,000 predictions concerning outcome, equipment need, duration of artificial ventilation, and duration of hospitalization for 300 recently admitted patients. The interviews were made within the first 24 hours after admission. The doctors being interviewed were usually (i.e., in over 90% of cases) unfamiliar with the patient. Information concerning the patient's general state of health, special pre-ICU events, and complications was offered to the interviewed clinician because this information represents standard admission data. It was found that the equipment need (represented by two different setups, high tech and low tech) could be predicted most reliably (96.4% correct predictions) compared with a prediction on outcome of ICU treatment (94.5%), on duration of artificial ventilation (75.4%), and on duration of stay (43.4%). There was no significant (p>0.05) difference in the reliability of predictions between residents and consultants. Factors influencing the postoperative equipment need varied with surgical specialty. The general state of health, as indicated by the ASA classification (p<0.001), and the specific intervention (all multiple-valve replacements needed the high-level equipment standard) appeared to be most important in cardiac surgery, while a state of septicemia was important in general surgery (p<0.001). Our findings suggest that ICU workstations may be standardized into at least two types. 相似文献
6.
Schramm C Huber S Protschka M Czochra P Burg J Schmitt E Lohse AW Galle PR Blessing M 《International immunology》2004,16(9):1241-1249
7.
Tumor Vascularity Is Not a Prognostic Factor for Malignant Melanoma of the Skin 总被引:1,自引:4,他引:1 下载免费PDF全文
Klaus J. Busam Marianne Berwick Karen Blessing Katrin Fandrey Sewon Kang Themis Karaoli Judy Fine Alistair J. Cochran Wain L. White Jason Rivers David E. Elder Duan-Ren Po Wen Bradley H. Heyman Raymond L. Barnhill 《The American journal of pathology》1995,147(4):1049-1056
Tumor vascularity has been proposed as a prognostic indicator for a number of solid tumors. Although a correlation between microvessel number and metastatic behavior has also been suggested for cutaneous melanoma, the small number of cases studied to date allows one to draw only preliminary conclusions. In this study, we have assessed tumor vascularity in cutaneous melanoma by comparing 60 cases of metastasizing and non-metastasizing tumors matched for tumor thickness, age, sex, and anatomic site. Ulex europaeus agglutinin I appeared to be the most suitable vascular marker for this study. Our results indicate that there was no statistically significant difference between the two groups with regard to tumor vascularity. Even after identifying 15 cases of thin (<1.0 mm thick) melanoma, there was no significant difference in the number of microvessels between metastasizing and non-metastasizing tumors. Comparison of patterns of vascular microarchitecture also failed to discriminate between the two groups. Thus, our results indicate that tumor vascularity may not be an independent prognostic factor for cutaneous melanoma. 相似文献
8.
Excitation of neuronal function in rabbit caudal ventrolateral medulla elevates plasma vasopressin 总被引:2,自引:0,他引:2
Injection of L-glutamate into the caudal ventrolateral medulla of the rabbit caused a dose-dependent increase in plasma vasopressin. Activity of the A1 noradrenergic cells within the caudal ventrolateral medulla appears to excite the vasopressin-secreting neuroendocrine cells within the hypothalamus. 相似文献
9.
Hepatocellular Hyperplasia, Plasmacytoma Formation, and Extramedullary Hematopoiesis in Interleukin (IL)-6/Soluble IL-6 Receptor Double-Transgenic Mice 总被引:2,自引:2,他引:2 下载免费PDF全文
Peter Schirmacher Malte Peters Gennaro Ciliberto Manfred Blessing Johannes Lotz Karl-Hermann Meyer zum Büschenfelde Stefan Rose-John 《The American journal of pathology》1998,153(2):639-648
Cytokines interact not only with membrane anchored receptors, but also with specific soluble receptors which circulate in the bloodstream. In general, soluble cytokine receptors such as soluble tumor necrosis factor receptor, soluble interleukin 1 receptor, and soluble interleukin 4 receptor compete with their membrane-bound counterparts for the ligands and therefore act as antagonists. In contrast, soluble receptors for cytokines of the interleukin-6 (IL-6) family complex with their ligands act agonistically. Interestingly, the complex of IL-6 and the soluble interleukin 6 receptor (sIL-6R) activates target cells that do not express the membrane-bound IL-6R and therefore cannot respond to IL-6. To identify cellular responses that are due to IL-6/sIL-6R but not to IL-6 alone, IL-6/sIL-6R double-transgenic mice were generated and compared with IL-6 single-transgenic mice. IL-6/sIL-6R transgenic mice develop a severe phenotype showing 1) marked hepatocellular hyperplasia frequently surrounded by peliosis and necrosis, 2) significant acceleration and aggravation of plasmacytoma formation, and 3) excessive activation of extramedullary hematopoiesis in spleen and liver followed by a subsequent increase of all cellular components in the peripheral blood. These in vivo data suggest that the sIL-6R recruits primarily unresponsive cell populations such as hematopoietic progenitor cells and hepatocytes to IL-6-induced proliferation, but also enhances the known mitogenic effect of IL-6 on plasma cells and thereby contributes to plasmacytoma formation. 相似文献
10.
Ndembi N Takehisa J Zekeng L Kobayashi E Ngansop C Songok EM Kageyama S Takemura T Ido E Hayami M Kaptue L Ichimura H 《Journal of acquired immune deficiency syndromes (1999)》2004,37(5):1641-1650
To monitor the presence of genotypic HIV-1 variants circulating in eastern Cameroon, blood samples from 57 HIV-1-infected individuals attending 3 local health centers in the bordering rural villages with Central African Republic (CAR) were collected and analyzed phylogenetically. Out of the 40 HIV-1 strains with positive polymerase chain reaction (PCR) profile for both gag and env-C2V3,12 (30.0%) had discordant subtype or CRF designation: 2 subtype B/A (gag/env), 1 B/CRF01, 2 B/CRF02, 1 CRF01/CRF01.A, 2 CRF11/CRF01, 1 CRF13/A, 1 CRF13/CRF01, 1 CRF13/CRF11, and 1 G/U (unclassified). Twenty-eight strains (70.0%) had concordant subtypes or CRF designation between gag and env: 27 subtype A and 1 F2. Out of the remaining 17HIV-1 strains negative for PCR with the env-C2V3 primers used, 10 (58.8%) had discordant subtype or CRF, and 7 (41.2%) had concordant one based on gag/pol/env-gp41 analysis. Altogether, a high proportion (22/57, 38.6%) of the isolates were found to be recombinant strains. In addition, an emergence of new forms of HIV-1 strains, such as subtype B/A (gag/env), B/CRF01 and B/CRF02, was identified. The epidemiologic pattern of HIV-1 in eastern Cameroon, relatively low and high prevalence of CRF02 and CRF11, respectively, was more closely related to those of CAR and Chad than that of other regions of Cameroon, where CRF02 is the most predominant HIV-1 strain. These findings strongly suggest that this part of Cameroon is a potential hotspot of HIV-1 recombination, with a likelihood of an active generation of new forms of HIV-1 variants, though epidemiologic significance of new HIV-1 forms is unknown. 相似文献