全文获取类型
收费全文 | 2245篇 |
免费 | 142篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 104篇 |
妇产科学 | 54篇 |
基础医学 | 349篇 |
口腔科学 | 20篇 |
临床医学 | 211篇 |
内科学 | 573篇 |
皮肤病学 | 42篇 |
神经病学 | 245篇 |
特种医学 | 101篇 |
外科学 | 173篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 125篇 |
眼科学 | 59篇 |
药学 | 162篇 |
中国医学 | 3篇 |
肿瘤学 | 142篇 |
出版年
2023年 | 7篇 |
2022年 | 21篇 |
2021年 | 41篇 |
2020年 | 26篇 |
2019年 | 35篇 |
2018年 | 35篇 |
2017年 | 42篇 |
2016年 | 55篇 |
2015年 | 60篇 |
2014年 | 91篇 |
2013年 | 108篇 |
2012年 | 129篇 |
2011年 | 166篇 |
2010年 | 97篇 |
2009年 | 82篇 |
2008年 | 139篇 |
2007年 | 164篇 |
2006年 | 138篇 |
2005年 | 138篇 |
2004年 | 136篇 |
2003年 | 137篇 |
2002年 | 105篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 22篇 |
1998年 | 34篇 |
1997年 | 25篇 |
1996年 | 31篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 20篇 |
1992年 | 15篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1974年 | 14篇 |
1973年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有2389条查询结果,搜索用时 0 毫秒
11.
Wilhelm D Mansmann U Neudeck H Matejevic D Vetter K Graf R 《Anatomy and embryology》2002,205(5-6):393-400
In a recent study we described an increase of elastic tissue fibres in blood vessel walls of placental stem villi during pre-eclampsia when compared to uncomplicated pregnancies. Furthermore, the thickness of these blood vessel walls was enhanced in pre-eclampsia. Since it is known that elastic tissue fibres increase in systemic hypertension, it may be assumed that the enhancement of elastic tissue fibres in placental stem villi during pre-eclampsia may be induced by the hypertension. To get further insight into this assumption, we examined the amount of elastic tissue fibres in stem villus blood vessels of placentae of pregnancies complicated by intrauterine growth retardation (isolated IUGR, fourteen cases), a disease without hypertension of the mother and such with pre-eclampsia and concomitant IUGR (IUGR+PE, nine cases). Each study group was compared with uncomplicated pregnancies (twenty-six cases). Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant lower intensities of orcein staining were calculated for blood vessel walls of placentae of isolated IUGR (P=0.0007) and IUGR+PE (P=0.0039) when compared to uncomplicated pregnancies each. Additionally, the blood vessel wall thickness of stem villi of isolated IUGR (P=0.0081) and IUGR+PE (P=0.0007) was significantly reduced. In comparison to the above mentioned investigation, our results show that, in contrast to isolated pre-eclampsia, elastic tissue fibres are decreased during pregnancies complicated by IUGR, independently of the occurrence of concomitant pre-eclampsia when compared to uncomplicated pregnancies. From our studies it may be considered that the increase of elastic tissue fibres in placentae of patients with isolated pre-eclampsia may be induced by systemic hypertension. Furthermore, our study underline arguments that IUGR may be an independent disease of the fetus. 相似文献
12.
Edward L. Baker Ann Smrek Renate D. Kimbrough Michael Hudgins Philip J. Landrigan John A. Liddle 《Clinical genetics》1977,12(3):134-138
Cholinesterase deficiency was detected in a young girl following an episode of post-anesthesia apnea. Subsequently, plasma and serum cholinesterase levels and dibucaine numbers were determined on blood samples from 56 members of her extended family. Including the proband, three individuals were identified with severe cholinesterase deficiency and 12 were found to have mild abnormalities. The occurrence of two genetic variants regulating cholinesterase production, the "silent" gene and the atypical enzyme, is postulated to account for the unusual pattern of inheritance in this family. Screening family members of confirmed cases is essential to prevent the potentially fatal consequences of this hereditary disorder. 相似文献
13.
Liu X Beaty TH Deindl P Huang SK Lau S Sommerfeld C Fallin MD Kao WH Wahn U Nickel R 《The Journal of allergy and clinical immunology》2003,112(2):382-388
BACKGROUND: Increased total serum IgE levels are a common characteristic of atopic disorders. Six potentially functional variants, including C-590T in the IL4 gene, C-1055T and Arg130Gln in the IL13 gene, and Ile50Val, Ser478Pro, and Gln551Arg in the IL4RA gene, have been evaluated for their involvement in the control of total serum IgE levels and related atopic disorders, but the results of these studies have been inconsistent. OBJECTIVE: We examined whether these 6 variants had genotypic effects on total serum IgE levels in 823 unrelated German children from a large infant cohort, the German Multicenter Atopy Study. METHODS: Marginal effect models were used for the analyses of the repeated IgE measurements. Weighted linear regression and family-based tests of association were performed to minimize the possibility of spurious effects caused by selection bias or confounding on the basis of ethnic background. RESULTS: There are significant associations between increased total serum IgE levels and 2 variants in the IL13 gene (P <.005 and.0002 for Arg130Gln and C-1055T, respectively). These genetic effects are unlikely to be due to solely linkage disequilibrium between 2 polymorphisms, population stratification, or nonrepresentative samples. In addition, exposure to maternal smoking appears to modify the above effects on total serum IgE levels. However, no statistical association was observed between this quantitative phenotype and the other 4 variants examined. CONCLUSION: These findings suggest that variants C-1055T and Arg130Gln of the IL13 gene might play an important role on total serum IgE production in this study population. 相似文献
14.
Lymphocyte transformation and production of a human mononuclear leucocyte chemotactic factor in patients with Hodgkin''s disease 下载免费PDF全文
H. Rühl W. Vogt Gudrun Bochert Susanne Schmidt H. Schaoua Renate Moelle 《Clinical and experimental immunology》1974,17(3):407-415
Human peripheral lymphocytes stimulated in vitro with phytohaemagglutinin (PHA) produce a factor with chemotactic activity for homologous monocytes. The production of this factor and lymphocyte transformation was investigated in patients with Hodgkin's disease. It has been found that the PHA response as measured by incorporation of [3H]thymidine was markedly depressed in patients when compared to the response of normal lymphocytes. In contrast, the production of the chemotactic factor was not significantly depressed in patients with Hodgkin's disease. 相似文献
15.
16.
Regitnig P Moser R Thalhammer M Luschin-Ebengreuth G Ploner F Papadi H Tsybrovskyy O Lax SF 《The Journal of pathology》2002,198(2):190-197
Local recurrence is a serious complication of breast carcinoma that reduces quality of life and influences prognosis. The aim of this study was to determine whether local recurrences of breast carcinoma are genetically related to the primary tumours. Forty cases of locally recurrent breast carcinomas (median onset: 3.6 years after primary surgery) were analysed: 22 patients had undergone breast-conserving therapy and 18 mastectomy. Eighteen microsatellites on chromosomes 2p, 3p, 5q, 10q, 11p, 11q, 13q, 17q, 17p, 18p were amplified by PCR using fluorescent-labelled primers, automatically detected after polyacrylamide gel electrophoresis and analysed for loss of heterozygosity (LOH) or microsatellite instability (MSI). Follow-up data were available for 39 cases with a median value of 89 months. All LOH and MSI found in the primary tumours were also present in the corresponding recurrences, indicating that they are genetically related to the primary tumours and not secondary malignancies in the same breast. MSI was found in three cases, of which one harboured MSI at more than two loci. The median value of LOH per case was significantly higher in the recurrent (four per case) compared to the primary tumours (two per case; p < 0.001, Mann-Whitney test), reflecting the genotype of tumour progression. Early local recurrence was associated with specific LOH for TP53.15 (p = 0.018, log-rank test) in the primary tumours. LOH on D13S1699 or D17S855 was associated with lymph node metastases (p = 0.024 and p = 0.019, respectively; chi-square test). In addition, tumour grade, lack of oestrogen or progesterone receptor expression, young patient age and early appearance of local recurrence significantly correlated with poor survival. The development of local recurrence despite clear resection margins may result from residual DCIS distant from the invasive carcinoma, homing of circulating tumour cells, or genetically altered, histologically normal breast tissue not immediately adjacent to the invasive carcinoma. 相似文献
17.
Retroviral vectors derived from murine leukemia virus (MLV) have been pseudotyped with a variant of the envelope glycoprotein (Env) of nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to result in [MLV(SIVagm-wt)] vector particles. The variant env gene encodes a full-length surface envelope glycoprotein (SU) and a C-terminally truncated transmembrane protein (TM). To change the coreceptor usage of this vector from CCR5 to CXCR4, which is predominant on human CD4-positive lymphocytes, the putative V3-loop of SIVagm SU was replaced by that of the T cell tropic HIV-1 variant BH10. The resulting [MLV(SIVagm-X4)] vectors were shown to specifically transduce CD4/CXCR4-positive cell lines, demonstrating the equivalent function in cell entry and choice of coreceptor usage of the V3-loops of SIVagm and HIV-1. These modified vectors were able to transduce primary human lymphocytes and were resistant to neutralization by sera from HIV-1-infected individuals. The [MLV(SIVagm-X4)] pseudotype vector generated is thus a promising candidate vector, e.g., for in vivo gene therapy of HIV-1 infection. 相似文献
18.
Renate H. Rosenthal Frank W. Ling Ted L. Rosenthal S. Gene McNeeley 《Psychosomatics》1984,25(11):833-841
One hundred three consecutive patients referred for treatment of chronic pelvic pain underwent MMPI testing, and 60 had diagnostic laparoscopy. A physical cause for the pain was found in 45 (75%) of the 60. However, three fourths (34) of patients with an organic cause for the pain also had evidence of psychopathology on the MMPI. Reassurance and education as to the role of stress in causing or exacerbating pain complaints appeared helpful. Most patients improve without major surgery. 相似文献
19.
Renate Wachner Christian Wittekind Sabine von Kleist 《Virchows Archiv : an international journal of pathology》1984,402(4):415-423
Summary One hundred and twenty seven cases of lung tumors were studied by the immunoperoxidase technique for the presence of CEA and-HCG. Twenty-nine of these tumors were additionally stained for keratin and SP1. CEA and SP1 could be demonstrated in 80% of the studied cases, while-HCG was found in only 9%. SP1 revealed an almost identical staining pattern to CEA and keratin was found only in squamous cell carcinomas. The tissue positivity of none of these three markers correlated with tumor size, lymphnodal involvement or histological type.This study was supported by Deutsche Stiftung für Krebsforschung - Dr. Mildred Scheel-Stiftung 相似文献
20.
Clara cell protein 16 (CC16) gene polymorphism influences the degree of airway responsiveness in asthmatic children 总被引:8,自引:0,他引:8
Sengler C Heinzmann A Jerkic SP Haider A Sommerfeld C Niggemann B Lau S Forster J Schuster A Kamin W Bauer C Laing I LeSouef P Wahn U Deichmann K Nickel R 《The Journal of allergy and clinical immunology》2003,111(3):515-519
BACKGROUND: Several studies have indicated linkage of chromosome 11q12-13 to asthma and associated traits. Among other candidate genes, the Clara cell protein 16 (CC16) gene maps to this region. CC16 is expressed in the bronchial epithelium and exhibits potent anti-inflammatory properties. A single-nucleotide polymorphism (SNP) in the CC16 gene (A38G) was previously associated with asthma. OBJECTIVE: We evaluated the role of the CC16 SNP in pediatric asthma and asthma severity in 2 German study populations. METHODS: The German Multicenter Allergy Study (MAS) cohort (n = 872, 94 asthmatic patients) and 112 allergic asthmatic children recruited in Freiburg, Germany, were included in the present study. Histamine provocations were performed at the age of 7 years in the MAS cohort to determine bronchial hyperreactivity; in the Freiburg study population a standardized exercise-induced decrease in FEV1 was evaluated. For genotyping, melting-curve analysis and restriction enzyme digestion were applied. RESULTS: No association of the CC16*38A allele with asthma could be observed in either study population. However, in asthmatic subjects (MAS cohort) PC(20)FEV(1) values were significantly lower in individuals homozygous or heterozygous for the CC16*38A allele compared with those in subjects with the CC16*38GG genotype (P <.05 and P <.03, respectively). Similarly, allergic asthmatic patients in the Freiburg cohort showed a significantly greater decrease in FEV1 after exercise when homozygous for the CC16*38A allele compared with that seen in asthmatic patients with the *38AG or *38GG genotype (P <.04 and P =.006, respectively). CONCLUSION: We conclude that the CC16*A38G SNP influences bronchial hyperreactivity and might be a genetic determinant of asthma severity in German children. 相似文献