全文获取类型
收费全文 | 1488597篇 |
免费 | 111066篇 |
国内免费 | 2862篇 |
专业分类
耳鼻咽喉 | 20685篇 |
儿科学 | 49789篇 |
妇产科学 | 38834篇 |
基础医学 | 208336篇 |
口腔科学 | 37654篇 |
临床医学 | 132917篇 |
内科学 | 301439篇 |
皮肤病学 | 30851篇 |
神经病学 | 121828篇 |
特种医学 | 60341篇 |
外国民族医学 | 674篇 |
外科学 | 229160篇 |
综合类 | 29345篇 |
现状与发展 | 2篇 |
一般理论 | 543篇 |
预防医学 | 110790篇 |
眼科学 | 32966篇 |
药学 | 108682篇 |
3篇 | |
中国医学 | 2716篇 |
肿瘤学 | 84970篇 |
出版年
2021年 | 12623篇 |
2019年 | 13463篇 |
2018年 | 18447篇 |
2017年 | 13873篇 |
2016年 | 15181篇 |
2015年 | 17414篇 |
2014年 | 24489篇 |
2013年 | 36250篇 |
2012年 | 51204篇 |
2011年 | 53983篇 |
2010年 | 31772篇 |
2009年 | 30181篇 |
2008年 | 50770篇 |
2007年 | 54094篇 |
2006年 | 54011篇 |
2005年 | 52744篇 |
2004年 | 51116篇 |
2003年 | 48774篇 |
2002年 | 47558篇 |
2001年 | 65766篇 |
2000年 | 67843篇 |
1999年 | 58231篇 |
1998年 | 17616篇 |
1997年 | 15750篇 |
1996年 | 15946篇 |
1995年 | 15044篇 |
1994年 | 14163篇 |
1993年 | 13173篇 |
1992年 | 45476篇 |
1991年 | 44333篇 |
1990年 | 42960篇 |
1989年 | 40802篇 |
1988年 | 37527篇 |
1987年 | 36794篇 |
1986年 | 34215篇 |
1985年 | 32914篇 |
1984年 | 24991篇 |
1983年 | 21005篇 |
1982年 | 12661篇 |
1981年 | 11570篇 |
1979年 | 21789篇 |
1978年 | 15300篇 |
1977年 | 12947篇 |
1976年 | 12089篇 |
1975年 | 12916篇 |
1974年 | 14954篇 |
1973年 | 14372篇 |
1972年 | 13115篇 |
1971年 | 11878篇 |
1970年 | 11164篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
Training needs analysis is considered essential to professional and organizational development, for continuing education and for incorporation into professional practice. Increasingly, nurses are encouraged to develop their health promotion role. Despite this there has been relatively little research in Scotland into the health promotion role of the hospital nurse. This study describes the results of a health promotion training needs analysis undertaken on qualified, hospital-based nurses in Lanarkshire, Scotland. Information on the nurses' current health promotion practices, their attitudes and beliefs, their views on role development and priorities for further training were collated, analysed and discussed within the framework of the Health Action Model. This model was originally designed to assist understanding of the gap that exists between an individual intention to act and the eventual health action. However, in this study the ways in which ‘cognitive factors’ (knowledge and beliefs) and ‘motivational factors’ (considering values, attitudes and drives) and pressures from social norms and significant others assisted in the understanding of the nurse's orientation to, and beliefs about, health promotion practice. Fifty-seven per cent of nurses in the study considered health promotion activities to be emerging in clinical care and 4% considered them to be advanced. The interest respondents have in role development and the further integration of health promotion activities into nursing practice was explored by ascertaining the nurses' attitudes and beliefs about their own health promotion role. Of 107 respondents, a majority 72 (67%) agreed health promotion interventions to be an important function of the nurse with 29 (27%) strongly agreeing (n=107). Sixty per cent stated they would be interested in developing their role and 30% were very strongly interested. Recommendations are therefore made for future planning and development strategies for the health promotion role of hospital nurses. 相似文献
962.
963.
Back pain in in-vitro fertilized and spontaneous pregnancies 总被引:1,自引:0,他引:1
Kristiansson P; Nilsson-Wikmar L; von Schoultz B; Svardsudd K; Wramsby H 《Human reproduction (Oxford, England)》1998,13(11):3233-3238
The influence of ovarian stimulation in in-vitro fertilization (IVF) on the
prevalence of back pain with onset during pregnancy was studied in 31 women
who became pregnant after IVF treatment and compared with that of 200
spontaneously pregnant women. A two times higher prevalence rate of sacral
pain in late pregnancy was reported among IVF pregnant women (P <
0.0001), as well as a significantly higher prevalence rate of positive
results of pelvic pain provocation tests performed in late pregnancy
(0.0001 < or = P < or = 0.015), as compared with that of the
spontaneously pregnant women. Among the IVF pregnant women, there was a
significant positive correlation between relaxin concentrations in early
pregnancy and the outcome of pelvic pain provocation tests (0.44 < or =
r < or = 0.51, P < 0.05). In addition, the serum relaxin
concentration was the factor that best explained differences in sacral pain
prevalence. When the influence of serum relaxin concentration on back pain
prevalence was taken into account, women carrying multiple pregnancies had
no more pain than women carrying singletons, and IVF pregnant women had no
more pain than spontaneously pregnant women. These results support the
hypothesis that relaxin is involved in the generation of pelvic pain in
pregnant women.
相似文献
964.
Molecular cloning and complete nucleotide sequence of galinsoga mosaic virus genomic RNA 总被引:1,自引:0,他引:1
Summary. The complete genomic sequence of galinsoga mosaic virus (GaMV) was determined. The genome consists of 3 803 nucleotides and
has five open reading frames (ORFs). The 5′ ORF (ORF 1) encodes a protein with predicted molecular mass of 23 kDa and readthrough
of its amber stop codon probably yields a 82 kDa protein (ORF 2). ORFs 3 and 4 encode two polypeptides with molecular masses
of 8 and 7 kDa, respectively. ORF 5 encodes the 36 kDa capsid protein. Amino acid sequence comparisons revealed that the nonstructural
proteins encoded by ORFs 1, 3, and 4 were more similar to the corresponding gene products of tobacco necrosis virus, strain
A, than to those of carmoviruses. Conversely, the coat protein was more similar to that of tombusviruses. The readthrough
region of the viral replicase (ORF 2) had high sequence homology with that of carmo-, tombus-, and necroviruses. Computer
analysis of the protein encoded by ORF 1 as well as of the corresponding product of turnip crinkle (TCV) and melon necrotic
spot (MNSV) carmoviruses revealed the presence of a sequence with local hydrophobicity and hydrophobic moment characteristic
of mitochondrial targeting sequence which may explain the origin of the carmovirus-induced multivesicular bodies from mitochondria.
Accepted August 25, 1997 Received June 18, 1997 相似文献
965.
P. K. Nandi 《Archives of virology》1998,143(7):1251-1263
Summary. The human prion peptide PrP106–126 polymerizes in the presence of DNA both in its circular and linearized forms under solution
conditions where the peptide alone does not polymerize. The polymerization process has been monitored by the increase in the
fluorescence of anilino naphthalene sulfonic dye which detects the availability of the hydrophobic surface(s) in the aggregate
as a consequence of polymerization. The polymerization is a nucleation dependent phenomenon as is evidenced from an existence
of a lag period before the onset of the polymerization and a strong dependence of the polymerization on the prion peptide
concentrations. The reaction is dependent on the pH as seen from rapid polymerization at pH 5 compared to the reaction at
neutral pH where no polymerization is observed after a relatively long period of incubation. The polymer has been characterized
as amyloid by using new absorbing and emitting species resulting from the interaction of the polymer with the amyloid specific
fluorescent dye, Thioflavine S. This is probably the first demonstration that an endogenous macromolecule can influence the
polymerization of a prion peptide. We have previously shown that there is a conformational change in the nucleic acid as a
consequence of this interaction. This prion peptide is considered as a model to understand prion diseases as is evidenced
from its toxicity towards primary brain cells in culture. The peptide encompasses one of the important amyloidogenic regions
of the normal cellular prion protein. Demonstration of nucleic acid induced polymerization of the normal and scrapie prion
isoforms accompanying a change in the nucleic acid conformation can establish a possible role of nucleic acid in prion disease.
Received January 8, 1997 Accepted March 4, 1998 相似文献
966.
Movement detection at the human big toe 总被引:1,自引:1,他引:0
967.
968.
969.
W. A. Bulman J. P. Iannotti K. Glowacki J. Bleuit C. C. Clark 《Journal of orthopaedic research》1995,13(2):220-229
Longitudinal growth of bone involves a complex sequence of cellular events in the cartilaginous epiphysis. Whole blood serum has been shown previously to be a potent stimulus to the cells of the growth plate, as demonstrated by its ability to activate the inositol phosphate-calcium second messenger system resulting in a rise in intracellular Ca2+. By manipulating the preparation of serum to functionally separate it into its constituent parts, we have shown that the processes of platelet lysis and activation of the clotting cascade are responsible for the generation of factors that stimulate this signaling mechanism in isolated bovine growth plate chondrocytes. Through a subsequent trial of bioactive agents generated in these processes, we identified and partially characterized several novel agonists of growth plate chondrocytes: adenosine triphosphate and adenosine diphosphate, the purine energy substrates, and bradykinin, the bioactive peptide generated in a side reaction of the clotting cascade, each induces a rise in intracellular Ca2+ via release from intracellular ion stores. Additionally, the three distinct isoforms of platelet-derived growth factor (AA, AB and BB), also released on platelet lysis, were compared with respect to their ability to stimulate the inositol phosphate-calcium second messenger system in growth plate chondrocytes. 相似文献
970.
Marvin Rubenstein Robert Saffrin Michael Shaw Sergey Muchnik Patrick Guinan 《The Prostate》1995,27(3):148-153
Orthotopic placement of in vitro propagated Dunning R3327 AT-3 tumor cells resulted in a greater percentage of tumor takes and a two-fold shift in the exponential growth curve compared to flank implantation. The orthotopic tumor appeared to disseminate preferentially to regional lymph nodes, rather than to the lungs which is characteristic of flank tumors. The results suggest an important role of stromal-epithelial interactions in the growth of this tumor. © 1995 Wiley-Liss, Inc. 相似文献