全文获取类型
收费全文 | 8262篇 |
免费 | 485篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 265篇 |
妇产科学 | 129篇 |
基础医学 | 1160篇 |
口腔科学 | 230篇 |
临床医学 | 702篇 |
内科学 | 1897篇 |
皮肤病学 | 126篇 |
神经病学 | 654篇 |
特种医学 | 382篇 |
外国民族医学 | 3篇 |
外科学 | 1501篇 |
综合类 | 189篇 |
一般理论 | 1篇 |
预防医学 | 573篇 |
眼科学 | 96篇 |
药学 | 396篇 |
中国医学 | 6篇 |
肿瘤学 | 383篇 |
出版年
2022年 | 53篇 |
2021年 | 139篇 |
2020年 | 89篇 |
2019年 | 101篇 |
2018年 | 146篇 |
2017年 | 138篇 |
2016年 | 103篇 |
2015年 | 146篇 |
2014年 | 174篇 |
2013年 | 244篇 |
2012年 | 323篇 |
2011年 | 374篇 |
2010年 | 217篇 |
2009年 | 200篇 |
2008年 | 316篇 |
2007年 | 387篇 |
2006年 | 344篇 |
2005年 | 332篇 |
2004年 | 327篇 |
2003年 | 316篇 |
2002年 | 292篇 |
2001年 | 294篇 |
2000年 | 257篇 |
1999年 | 253篇 |
1998年 | 125篇 |
1997年 | 124篇 |
1996年 | 101篇 |
1995年 | 74篇 |
1994年 | 75篇 |
1993年 | 57篇 |
1992年 | 139篇 |
1991年 | 127篇 |
1990年 | 151篇 |
1989年 | 162篇 |
1988年 | 136篇 |
1987年 | 148篇 |
1986年 | 137篇 |
1985年 | 147篇 |
1984年 | 121篇 |
1983年 | 98篇 |
1982年 | 46篇 |
1980年 | 60篇 |
1979年 | 96篇 |
1978年 | 65篇 |
1977年 | 57篇 |
1975年 | 52篇 |
1974年 | 63篇 |
1973年 | 51篇 |
1972年 | 64篇 |
1970年 | 48篇 |
排序方式: 共有8775条查询结果,搜索用时 812 毫秒
61.
We performed transurethral resections of the prostate in 100 patients under local anesthesia supplemented when appropriate by intravenous medication. In the first part of the study (40 patients) local anesthesia was infiltrated into the prostate transurethrally only, while in the second part (60 patients) infiltration was performed transurethrally and perineally. Prostate sizes ranged from 5 to 50 gm., and pain control was excellent in the majority of the patients, especially when perineal infiltration was added to the procedure. Of the patients 98 per cent said they would do it again, no patient required conversion to general anesthesia and there were no significant complications relating to the anesthesia. Local anesthesia with intravenous supplementation can be performed successfully in the majority of the patients with small to moderately sized prostate glands. 相似文献
62.
Mazur G Bogunia-Kubik K Wróbel T Karabon L Polak M Kuliczkowski K Lange A 《Immunology letters》2005,96(2):241-246
Multiple myeloma (MM) is a plasma cell malignancy characterised by bone marrow infiltration and the presence of a monoclonal protein in serum and/or urine. Interleukin-6 (IL-6) has been identified as one of the most important cytokines that contributes to myeloma cell survival and proliferation. Recent investigations suggest involvement of another cytokine, IL-10, in the activation of MM cells. The present study aimed to determine whether there is an association between the polymorphic features located within the promoter regions of IL-6 and IL-10 genes and progression the disease. IL-6 (-174 G/C) and IL-10 (-1082 A/G, -819 C/T, -592 A/C) promoter single nucleotide polymorphisms (SNPs) were determined by PCR-SSP technique using commercial primers. Our single centre results were compared with the data from literature and combined in cumulative analysis employing the Mantel-Haenszel method. In univariate analysis, only IL-10 ACC genotype tended to prevail in our (Polish) group of patients. None of IL-6 genotypes or IL-10 (-1082) alleles was found to associate with MM disease either in our single centre or in cumulative study. Among patients who died within 36 months of diagnosis, a significant prevalence (P < 0.05) of IL-6 heterozygous cases as opposed to IL-6 homozygotes was observed. IL-6 and IL-10 promoter gene polymorphisms were not found to associate with the susceptibility to the development of MM. However, the IL-6 polymorphic features appeared as factors that might affect the survival of MM patients. The latter observation warrants further study. 相似文献
63.
Łaba A Ostrowska A Patrzałek D Paradowski L Lange A 《Archivum immunologiae et therapiae experimentalis》2005,53(5):442-453
INTRODUCTION: The successful use of hepatocytes depends on a reliable demonstration of the functional and morphological integrity of isolated cells. Herein we investigated whether the isolation and cryopreservation of primary human hepatocytes can compromise cell viability and liver-specific characteristics. MATERIAL/METHODS: Hepatocytes were isolated from encapsulated human liver segments by a modified 2-step perfusion technique. Isolated cells were Percoll-purified, cryopreserved, and stored in liquid nitrogen for 1-12 months. For rapid assessment of fresh and cryopreserve/thawed hepatocyte yield and viability, the cells were stained with trypan blue or labeled with fluorochromes. For immunocytochemical analysis, the cells were labeled with monoclonal antibodies for the presence of the following antigens and chemokines: CD3, CD45Ro, CD45Ra, CD34, CD68, CD90, CD95, CD20, HLA-DR, Ki67, PCNA, Bcl-2, p53, CXCR3, CXCR4, and SDF-1. The cells were tested for several specific functions, such as ureagenesis, energy status, MTT activity, lactate dehydrogenase leakage, and total CYP450 content. RESULTS: Assessment of both freshly isolated (Percoll-purified) and cryopreserved/thawed hepatocytes revealed a low constitutive level of contamination by non-parenchymal cells compared with crude (unpurified) preparations and tissue sections. All viable hepatocytes showed intact morphology and retained CYP450 protein, energy status, and urea synthesis. CONCLUSIONS: Modifications in hepatocyte preparations, such as depletion of dead, damaged, and nonparenchymal cells, improves cell purity, which can be adapted to further evaluation of hepatocyte immunogenicity. These data illustrate the importance and feasibility of human hepatocyte banking. 相似文献
64.
Mechanisms of cell adhesion and extracellular matrix formation are primary processes in the interaction with the material surface of an implant which are controlled by integrin receptors. The aim of our study was to find out whether beta1- and beta3-integrins of osteoblastic cells sense the surface topography of titanium, and if structural alterations of integrin adhesions were involved in the organization of fibronectin. Pure titanium surfaces were modified by polishing (P), machining (NT), blasting with glass spheres (GB), and blasting with corundum particles (CB) resulting in increasing roughness. Confocal microscopic investigations revealed fibrillar adhesions of beta1- and alpha5-integrins on P, NT, and GB, but on CB with its sharp edges these integrin subunits did not form fibrillar adhesions. beta3 generally appeared in focal adhesions. We observed aligned fibrillar structures of fibronectin on NT not only on the basal site but interestingly, also on the apical cell surface. In contrast, on CB, fibronectin appeared apically clustered. We suggest that this alignment of fibronectin fibrils depends on the directed actin cytoskeleton and in particular, on the capability of the beta1-integrins to form fibrillar adhesions, which is affected by the surface roughness of titanium. 相似文献
65.
A live, attenuated, recombinant influenza vaccine (Alice strain) administered intranasally was evaluated in high school students and compared with intranasal placebo and subcutaneous, inactivated, bivalent influenza vaccine. The Alice strain was antigenic, increasing the geometric mean titer (GMT) from a prestudy level of 30.2 to a postvaccine level of 189.6. The inactivated vaccine increased the GMT from 32.9 to 361.8. There was no increase in the GMT among the placebo recipients. The Alice strain produced little reaction. With an antigenic, safe, acceptable, live, attenuated influenza vaccine available, immunization on a widespread basis should be considered. 相似文献
66.
Niels Fisker Court Pedersen Marianne Lange Nga Thien Tich Nguyen Kim Thien Tich Nguyen J?rgen Georgsen Peer Brehm Christensen 《Journal of clinical virology》2004,31(1):46-52
BACKGROUND: Denmark has a low incidence of acute hepatitis B (HBV) infections but the impact of an increasing number of immigrants with chronic HBV infection on HBV transmission is unknown. OBJECTIVES: To characterise individuals with chronic and acute HBV infection in a defined region and to examine the importance of different risk groups for the current HBV transmission. METHODS: During 2000-2001 all consecutive HBV infected individuals routinely diagnosed through the regional HBV serology laboratory in the County of Funen were classified according to ethnicity, presumed route of transmission and stage of infection based on clinical data mainly supplied by the requesting physician. HBV DNA was sequenced and subjected to phylogenetic analysis. RESULTS: Of 309 identified cases, 91 (29%) were classified as acute infection. HBV DNA sequencing was possible in 54 (59%) of these cases. Phylogenetic analysis showed that HBV isolated from injecting drug users (IDUs) was identical or closely related. Among acute cases acquired in Denmark 89% (74/83) were seen in IDUs (65) or in individuals presumably exposed to IDUs (nine) and phylogenetic analysis corroborated the assumption of IDU related transmission in every case with available sequence data. Among 83 ethnic Danes who acquired their HBV infection in Denmark, no new cases of transmission from immigrants were detected. CONCLUSION: Injecting drug use was the single most important factor for hepatitis B transmission in Denmark. The current Danish vaccination strategy is unable to protect IDUs from HBV infection and IDUs pose a greater risk of HBV transmission to the general population than immigrants. 相似文献
67.
68.
69.
DNA probe analysis for carrier detection and prenatal diagnosis of Duchenne muscular dystrophy: a standard diagnostic procedure. 总被引:7,自引:4,他引:7 下载免费PDF全文
E Bakker E J Bonten L F De Lange H Veenema D Majoor-Krakauer M H Hofker G J Van Ommen P L Pearson 《Journal of medical genetics》1986,23(6):573-580
Thirteen marker loci localised on the short arm of the X chromosome are available for use in genetic studies for Duchenne muscular dystrophy (DMD). This large number of probes detecting about 20 RFLPs encouraged us to set up a standard procedure using a sequence of selected probes and restriction enzymes for the diagnosis of DMD families. The application of DNA probe analysis for carrier detection and prenatal diagnosis, involving 61 pedigrees of both familial and isolated cases, has yielded the following results. Carrier detection using flanking markers was possible in more than 75% of the cases (104 out of 136 females) with a reliability of better than 98%. Prenatal diagnosis was possible in 95% of the cases (65 out of 68 proven carriers or women at risk). Twenty-three prenatal diagnoses were performed on male fetuses; 13 appeared to have a low risk for DMD (less than 1%) and thus the pregnancies continued. Seven have since come to term and the male infants have normal CK levels. The genetic distances of the loci relative to the DMD locus and their order on the short arm of the X chromosome were deduced from our total DMD family material and are not significantly different from those reported earlier. For 754 (DXS84) we found a genetic distance of 5 cM with a lod score of +12.4 and 95% confidence limits between 2 and 12 cM. Similar data were obtained for pERT87 (DXS164), suggesting that in our family material both loci are tightly linked. Multiply informative recombination showed that both 754 and pERT87 map proximal to the DMD mutations in the cases studied. The high frequency of DMD mutations and its relation to the observed instability in this part of the genome will be discussed. Unequal crossing over is proposed as one of the mechanisms contributing to the high mutation frequency. 相似文献
70.
L. Lange M. Echt K. Kirsch O. H. Gauer 《Pflügers Archiv : European journal of physiology》1972,337(4):311-322
Summary The phenomena of stress-relaxation and capillary outward filtration were studied in the isolated rabbit ear, perfused with blood at constant flow. The volume increase, as measured by the plethysmograph, following elevation of venous outflow pressure to 20 mm Hg for 4 min was predominantly due to capillary outward filtration in the norepinephrine constricted vascular bed (0.5 g/min). With papaverine induced dilatation (0.08 mg/min) this persistent volume increase could be attributed mainly to stress-relaxation of the veins. Engorgement of venous vessels as well as capillary outward filtration led to an increase of the ear volume that is measured by the plethysmographic technique. The photographic-photoelectric measurement of venous diameter changes was used in these experiments to distinguish intravascular from extravascular volume changes. The moduli of volume elasticity were calculated for smaller and larger veins (mean diameter 0.133 mm and 0.553 mm) with norepinephrine constriction. It has been demonstrated that the smaller veins were about seven times less distensible than the larger veins.This investigation was supported by Contract F44620-71-C-0117 of the USAF School of Aerospace Medicine, European Office of Aerospace Research (OAR), U.S. Air Force and Deutsche Forschungsgemeinschaft.This work was presented in part at the 39. Tagung der Deutschen Physiologischen Gesellschaft, Erlangen, April 1972 [Pflügers Arch. Suppl.332, R 54 (1972)]. 相似文献