全文获取类型
收费全文 | 1315篇 |
免费 | 67篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 81篇 |
妇产科学 | 54篇 |
基础医学 | 170篇 |
口腔科学 | 32篇 |
临床医学 | 135篇 |
内科学 | 248篇 |
皮肤病学 | 29篇 |
神经病学 | 46篇 |
特种医学 | 115篇 |
外科学 | 224篇 |
综合类 | 42篇 |
预防医学 | 85篇 |
眼科学 | 14篇 |
药学 | 73篇 |
中国医学 | 2篇 |
肿瘤学 | 89篇 |
出版年
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 19篇 |
2019年 | 26篇 |
2018年 | 36篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 25篇 |
2014年 | 64篇 |
2013年 | 59篇 |
2012年 | 51篇 |
2011年 | 56篇 |
2010年 | 55篇 |
2009年 | 54篇 |
2008年 | 49篇 |
2007年 | 82篇 |
2006年 | 38篇 |
2005年 | 48篇 |
2004年 | 40篇 |
2003年 | 29篇 |
2002年 | 26篇 |
2001年 | 30篇 |
2000年 | 15篇 |
1999年 | 24篇 |
1998年 | 35篇 |
1997年 | 40篇 |
1996年 | 27篇 |
1995年 | 27篇 |
1994年 | 33篇 |
1993年 | 23篇 |
1992年 | 10篇 |
1991年 | 19篇 |
1990年 | 10篇 |
1989年 | 22篇 |
1988年 | 29篇 |
1987年 | 20篇 |
1986年 | 19篇 |
1985年 | 34篇 |
1984年 | 17篇 |
1983年 | 26篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1980年 | 12篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 13篇 |
1976年 | 17篇 |
1975年 | 17篇 |
1973年 | 9篇 |
1972年 | 8篇 |
排序方式: 共有1445条查询结果,搜索用时 0 毫秒
1.
Balloon dacryocystoplasty: indications and contraindications 总被引:3,自引:0,他引:3
2.
3.
4.
Chromosomal aberrations and micronucleus frequency in nurses occupationally exposed to cytotoxic drugs 总被引:4,自引:1,他引:4
Anwar Wagida A.; Salama Somaia I.; Serafy Mostafa M.EI; Hemida Samia A.; Hafez Ahmed S. 《Mutagenesis》1994,9(4):315-317
In this study, we evaluated the effect of low level occupationalexposure of nurses in a medical oncology unit in Cairo, Egypt,to anticancer drugs. Twenty nurses who constantly handled thesedrugs and 20 controls, matched according to age and sex, wereexamined. Metaphase chromosomes were studied. Percentages ofmetaphases with chromosomal aberrations were significantly higher(P < 0.001) in the exposed group (6.1 ± 2.7) versusthe controls (2.6 ± 1.6). The detected chromosomal aberrationswere in the form of chromatid gaps, chromatid breaks and acentricfragments. Micronucleated peripheral blood lymphocytes werealso analyzed in cytochalasin B treated binucleated lymphocytes.There was significant increase in cells with micronuclei (P< 0.001) in nurses (10.05 ± 4.71) in comparison tothe matched control (5.42 ± 2.22) (P < 0.001). Nursesexposed to the cytotoxic drugs for 相似文献
5.
Survey of CAG/CTG repeats in human cDNAs representing new genes: candidates for inherited neurological disorders 总被引:3,自引:2,他引:3
Neri C; Albanese V; Lebre AS; Holbert S; Saada C; Bougueleret L; Meier-Ewert S; Le Gall I; Millasseau P; Bui H; Giudicelli C; Massart C; Guillou S; Gervy P; Poullier E; Rigault P; Weissenbach J; Lennon G; Chumakov I; Dausset J; Lehrach H; Cohen D; Cann HM 《Human molecular genetics》1996,5(7):1001-1009
6.
Evaluation of {beta}-endorphin and interleukin-6 in seminal plasma of patients with certain andrological diseases 总被引:1,自引:0,他引:1
Zalata Adel; Hafez Tarek; Van Hoecke Marie Jose; Comhaire Frank 《Human reproduction (Oxford, England)》1995,10(12):3161-3165
Human semen contains large amounts of opioid peptides and cytokines.We have measured the concentrations of interleukin (IL)-6 in140 semen samples and of -endorphinin 77 semen samples. Themedian concentration of endorphinin seminal plasma from normozoospermicmen(n = 23) was 154.7 pg/ml (10th90th percentiles, 42.0774.6),and there was no significant difference in the -endorphin concentrationamong normozoospermic, oligozoospermic (n= 28), asthenozoospermic(n= 15), azoospermic(n= 4) and post-vasectomy (n= 7) samples.There was no correlation between -endorphin concentration andsperm characteristics, nor with blood hormones. Endorphinconcentration was lower in cases with immunelogical infertility,as revealed by a positive direct mixedantiglobulin reactiontest (n = 12) ( > 0.01), than inmatched controls. The medianconcentration of IL-6 insamples with normal sperm concentration,motility andmorphology with or without white blood cells (n=39) was 26.1 pg/ml (10th90th percentiles, 7.3172.3),and there was no significant difference in the IL-6 concentrationamong normozoospermic, oligozoospermic (n= 46),asthenozoospermic(n= 32), azoospermic (n= 13) and post-vasectomy (n= 10) samples.The IL-6 concentration was significantly higher in cases ofvaricocele (n= 22)without white blood cells in semen (P <0.001) than in matched controls without varicocele (n= 23).In addition, the IL-6 concentration was elevated (P < 0.0001)in cases with accessory sex gland inflammation (n= 40). IL-6concentration was positively correlated with white blood cellsin semen (n= 60, r = 0.59, P < 0.0001), but there was nocorrelation with -endorphin concentration. The IL-6 concentrationchosen to differentiate between cases with and without accessorygland inflammation was 45.3 pg/ml, with a specificity of 80.6%and a sensitivity of 92.5%. It is concluded that -endorphinin seminal plasma playsan immune suppressive role, and thatincreased IL-6 concentration may be related to testicular dysfunctionincases with varicocele. Furthermore, IL-6 is an accurate markerof accessory sex gland inflammation. 相似文献
7.
8.
Choi RY Lucarelli MJ Imesch PD Hafez GR Albert DM Dortzbach RK 《Arch. Ophthalmol.》1999,117(4):535-537
A 43-year-old woman had unilateral exophthalmos caused by primary orbital Ewing sarcoma. Specialized immunohistochemical stains, primarily MIC-2 (CD99), aided in the diagnosis of Ewing sarcoma. Twenty-two months after radiotherapy and multiagent chemotherapy, the patient remained tumor free. To our knowledge, this is the first reported case of orbital Ewing sarcoma to present in an adult beyond the fourth decade of life. 相似文献
9.
Hafez HM Berwanger CS Lintott P Delis K Wolfe JH Mansfield AO Stansby G 《Journal of vascular surgery》2000,31(3):520-531
PURPOSE: Monocyte CD14 and its soluble form (sCD14) mediate the proinflammatory response to endotoxemia. The aim of this study was to measure the changes to these factors after major aortic surgery and the possible inhibitory role of transforming growth factor-beta(1) (TGF-beta(1)) during these procedures. METHODS: Twenty-four patients with supraceliac aortic crossclamping during thoracoabdominal aortic aneurysm (TAAA) repair and 12 patients with infrarenal aortic crossclamping as part of infrarenal aneurysm repair (AAA) were studied. Blood was collected at incision, aortic clamping, and reperfusion and at 1, 8, and 24 hours after reperfusion. Samples were assayed for endotoxin, peripheral blood monocyte CD14 expression, sCD14, tumor necrosis factor-alpha, and TGF-beta(1). RESULTS: Although there was significant endotoxemia on reperfusion in both groups of patients, peak plasma endotoxin levels were significantly higher in patients with TAAA (P =.001). Monocyte CD14 and plasma sCD14 were significantly decreased in patients with TAAA at reperfusion and 1 hour after reperfusion (P <.01, both points). In patients with AAA, a significant upregulation of CD14 was observed at 24 hours after reperfusion (P <.01), but no significant changes in sCD14 were observed. TNF-alpha showed no significant changes during the study period in both groups. In patients with TAAA, TGF-beta(1) showed significant elevation at all time points (P <.01); whereas in patients with AAA, TGF-beta(1) showed no significant changes. CONCLUSION: Splanchnic ischemia reperfusion in patients who undergo supraceliac aortic clamping is associated with peripheral blood monocyte CD14 suppression and significant elevation of TGF-beta(1). TGF-beta(1) may play an important role in modulating the immune response to endotoxemia during major aortic aneurysm surgery. 相似文献
10.
OBJECTIVES: To determine the spectrum of N and G genotypes of respiratory syncytial virus (RSV) causing respiratory tract infection and whether particular genotypes are associated with severity of infection. PATIENTS AND METHODS: Nasopharyngeal aspirates (NPAs) were obtained from 114 infants with acute respiratory tract infection due to RSV over two seasons. Viral mRNA was extracted from NPAs or cultured virus, reverse transcribed, and the cDNA amplified by the polymerase chain reaction using primers directed to parts of the N and G gene respectively. Amplicons were separately digested with four different restriction endonucleases for each gene. The fragments were separated by agarose gel, electrophoresis, and the electrophoretic patterns used to assign the various genotypes. Disease severity was assessed as very mild (upper respiratory tract signs only), mild (coryza and signs of lower respiratory tract infection), moderate (requiring nasogastric or intravenous fluids), and severe (requiring oxygen or ventilation). RESULTS: Five of the six known N genotypes were detected, but NP4 and NP2 were found most frequently. There was no association between N genotype and disease severity. Six G (SHL) genotypes were detected. Significantly (p = 0.04) more of the infants infected with the SHL2 genotype had severe or moderate disease. CONCLUSIONS: During the seasonal peaks of RSV respiratory tract infection at least 10 different RSV genotypes cocirculated. While there is no association between N genotypes and disease severity, infection with the SHL2 G genotype appears to result in moderate to severe disease. 相似文献