全文获取类型
收费全文 | 1623篇 |
免费 | 88篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 65篇 |
妇产科学 | 20篇 |
基础医学 | 154篇 |
口腔科学 | 27篇 |
临床医学 | 147篇 |
内科学 | 378篇 |
皮肤病学 | 111篇 |
神经病学 | 38篇 |
特种医学 | 217篇 |
外科学 | 180篇 |
综合类 | 42篇 |
预防医学 | 103篇 |
眼科学 | 6篇 |
药学 | 36篇 |
中国医学 | 3篇 |
肿瘤学 | 191篇 |
出版年
2020年 | 11篇 |
2019年 | 13篇 |
2017年 | 15篇 |
2016年 | 22篇 |
2015年 | 30篇 |
2014年 | 35篇 |
2013年 | 82篇 |
2012年 | 31篇 |
2011年 | 37篇 |
2010年 | 63篇 |
2009年 | 68篇 |
2008年 | 34篇 |
2007年 | 48篇 |
2006年 | 36篇 |
2005年 | 54篇 |
2004年 | 35篇 |
2003年 | 32篇 |
2002年 | 35篇 |
2001年 | 40篇 |
2000年 | 21篇 |
1999年 | 31篇 |
1998年 | 86篇 |
1997年 | 75篇 |
1996年 | 77篇 |
1995年 | 50篇 |
1994年 | 63篇 |
1993年 | 51篇 |
1992年 | 17篇 |
1991年 | 24篇 |
1990年 | 23篇 |
1989年 | 43篇 |
1988年 | 45篇 |
1987年 | 32篇 |
1986年 | 26篇 |
1985年 | 28篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 21篇 |
1981年 | 19篇 |
1980年 | 13篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1975年 | 15篇 |
1974年 | 8篇 |
1973年 | 18篇 |
1972年 | 10篇 |
1971年 | 11篇 |
1970年 | 10篇 |
排序方式: 共有1744条查询结果,搜索用时 15 毫秒
21.
A modified technique for catheterization of the pulmonary artery was developed. It involves the passage of a tapered, movable-core, J-tipped guide wire across the right ventricle into the pulmonary artery followed by the advancement of a straightened Grollman pigtail catheter. The technique was successful in 34 of 34 pulmonary artery catheterizations. The method avoids prolonged catheter manipulation within the right ventricle. In addition, since the catheter does not cross the tricuspid valve until the guide wire has been advanced, the occasional complication of the pigtail "hooking" on a tricuspid valve leaflet or chordae tendineae during catheter withdrawal and manipulation is prevented. 相似文献
22.
Jun Aoki M.D. Richard P. Moser Jr. LTC MC USA Tuyethoa N. Vinh M.D. 《Skeletal radiology》1989,18(6):427-434
This study reviews the demographic, radiologic, and histologic characteristics of 13 cases of an important primary skeletal neoplasm, giant cell tumor of bone, occurring in an uncommon location, the scapula. that eight of 13 patients presented prior to 20 years of age contrasts significantly with the typical age distribution (between 20–40 years) encountered in giant cell tumors arising in long bones. As it does elsewhere in the skeleton, giant cell tumor of the scapula frequently demonstrates cystic and/or telangiectatic components on histologic examination. The radiologic appearances of giant cell tumor in the scapula and in more typical locations are similar and include: (1) well-defined (geographic) margins, occasionally with a delicate sclerotic rim, (2) prominent trabeculations, (3) expanded bone contour, (4) frequent extension to the subchondral plate, and (5) absence of internal mineralization. Tumor sites within the scapula included: coracoid process, acromion, and body (three cases each); glenoid (two cases); and superior and inferior angles (one case each).The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, the Department of Defense, or the Uniformed Services University of the Health Sciences. 相似文献
23.
Verschuren MC; Blom B; Bogers AJ; Spits H; van Dongen JJ 《International immunology》1998,10(12):1873-1880
Recombination of deltaRec to psiJalpha will delete the TCR delta gene,
which is thought to play an important role in the bifurcation of the TCR
alphabeta versus TCR gammadelta differentiation lineages. We recently
detected a DNA-binding protein in human thymocytes, the so- called PJA-BP,
which recognizes the psiJalpha gene segment and might be one of the factors
involved in the regulation of preferential deltaRec- psiJalpha
rearrangements. We now investigate PJA-BP expression and its correlation
with TCR delta gene deletion in thymocytes. Our electrophoretic mobility
shift assay experiments showed that the PJA-BP is evolutionary conserved in
human, murine and simian thymocytes. Using a large series of human
hematopoietic malignancies (n = 30), we conclude that PJA-BP expression is
thymocyte specific and seems to be restricted to thymocytes committed to
the TCR alphabeta lineage. Analysis of seven well-defined human thymocyte
subpopulations showed that preferential deltaRec-psiJalpha rearrangements
as well as PJA-BP expression can be detected from the immature
CD34-/CD1+/CD3- /CD4+/CD8alpha+beta- thymocyte differentiation stage
onwards. These experiments indicate that expression of PJA-BP in human
thymocytes starts simultaneously with preferential deltaRec-psiJalpha
rearrangements, which supports our hypothesis that PJA-BP is one of the
factors involved in the preferential recombination of deltaRec to
psiJalpha.
相似文献
24.
25.
Guy RJ Breschkin AM Keenan CM Catton MG Enriquez AM Hellard ME 《Journal of acquired immune deficiency syndromes (1999)》2005,38(4):495-499
Between 1999 and 2000, new diagnoses of HIV in Victoria (Australia) rose by 41%, from 140 to 197. In this time period, sera from new HIV diagnoses were tested using the Organon Teknika "detuned" enzyme immunoassay (EIA). We compared the results of the detuned EIA with incident infections defined by surveillance (on the basis of a previous negative or indeterminate HIV test and/or a seroconversion illness within the 12 months preceding HIV diagnosis). Of 317 specimens, 97 (31%) incident infections and 114 (36%) recent infections were detected using surveillance and detuned EIA, respectively. The detuned assay misclassified 11 cases with AIDS and 2 cases with CD4 counts < or = 200 micro3 (probable long-standing infections) as recent infections and was unable to identify 31 (32%) of 97 cases previously classified as incident cases by surveillance. The assay detected an extra 35 recent infections that were previously classified as nonincident by surveillance. By combining the detuned assay and surveillance, 132 (42%) incident infections were identified from 317 specimens, 36% more than surveillance alone. We recommend that a detuned assay or similar test become part of the routine strategy to identify incident infections in Victoria. Incident infections provide important information for targeting prevention strategies and the opportunity to interrupt ongoing viral transmission. 相似文献
26.
Utility of a multiplex PCR assay for detecting herpesvirus DNA in clinical samples 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Druce J Catton M Chibo D Minerds K Tyssen D Kostecki R Maskill B Leong-Shaw W Gerrard M Birch C 《Journal of clinical microbiology》2002,40(5):1728-1732
A multiplex PCR was designed to amplify herpes simplex virus types 1 and 2, cytomegalovirus, and varicella-zoster virus DNA present in a diverse range of clinical material. The susceptibility of these viruses to in vivo inhibition by at least one antiviral drug was an important consideration in their inclusion in the multiplex detection system. An aliquot of equine herpesvirus was introduced into each specimen prior to extraction and served as an indicator of potential inhibitors of the PCR and a detector of suboptimal PCR conditions. Compared to virus isolation and immunofluorescence-based antigen detection, the multiplex assay yielded higher detection rates for all viruses represented in the assay. The turnaround time for performance of the assay was markedly reduced compared to those for the other techniques used to identify these viruses. More than 21,000 tests have been performed using the assay. Overall, the multiplex PCR enabled the detection of substantially increased numbers of herpesviruses, in some cases in specimens or anatomical sites where previously they were rarely if ever identified using traditional detection methods. 相似文献
27.
28.
Missense mutation in a von Willebrand factor type A domain of the alpha 3(VI) collagen gene (COL6A3) in a family with Bethlem myopathy 总被引:2,自引:0,他引:2
Pan TC; Zhang RZ; Pericak-Vance MA; Tandan R; Fries T; Stajich JM; Viles K; Vance JM; Chu ML; Speer MC 《Human molecular genetics》1998,7(5):807-812
The Bethlem myopathy is a rare autosomal dominant proximal myopathy
characterized by early childhood onset and joint contractures. Evidence for
linkage and genetic heterogeneity has been established, with the majority
of families linked to 21q22.3 and one large family linked to 2q37,
implicating the three type VI collagen subunit genes, COL6A1 (chromosome
21), COL6A2 (chromosome 21) and COL6A3 (chromosome 2) as candidate genes.
Mutations of the invariant glycine residues in the triple-helical
domain-coding region of COL6A1 and COL6A2 have been reported previously in
the chromosome 21-linked families. We report here the identification of a
G-->A mutation in the N-terminal globular domain-coding region of COL6A3
in a large American pedigree (19 affected, 12 unaffected), leading to the
substitution of glycine by glutamic acid in the N2 motif, which is
homologous to the type A domains of the von Willebrand factor. This
mutation segregated to all affected family members, to no unaffected family
members, and was not identified in 338 unrelated Caucasian control
chromosomes. Thus mutations in either the triple-helical domain or the
globular domain of type VI collagen appear to cause Bethlem myopathy.
相似文献
29.
An allergic reaction following intrauterine insemination 总被引:1,自引:0,他引:1
Intrauterine insemination is a common procedure used for the treatment of
different causes of infertility. Adverse reactions associated with this
procedure are very rare and usually the procedure is well tolerated by the
patient. We report a case of an allergic reaction after intrauterine
insemination. The patient developed fever, difficulty breathing and
wheezing in both lung fields. Although a low concentration of penicillin in
the medium was used, it caused a significant allergic reaction. When
intrauterine insemination was performed in subsequent cycles with an
antibiotic-free medium, no allergic reaction occurred, and the procedure
was well tolerated by the patient. A careful allergy history is essential
in patients pursuing infertility treatment where antibiotics are utilized.
Patients who are known to be allergic to penicillin should have semen
prepared by an antibiotic-free medium.
相似文献
30.