全文获取类型
收费全文 | 1487篇 |
免费 | 74篇 |
国内免费 | 98篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 52篇 |
妇产科学 | 16篇 |
基础医学 | 216篇 |
口腔科学 | 33篇 |
临床医学 | 241篇 |
内科学 | 322篇 |
皮肤病学 | 91篇 |
神经病学 | 45篇 |
特种医学 | 81篇 |
外科学 | 137篇 |
综合类 | 63篇 |
预防医学 | 64篇 |
眼科学 | 110篇 |
药学 | 106篇 |
中国医学 | 5篇 |
肿瘤学 | 62篇 |
出版年
2021年 | 26篇 |
2020年 | 10篇 |
2019年 | 21篇 |
2018年 | 21篇 |
2017年 | 26篇 |
2016年 | 27篇 |
2015年 | 32篇 |
2014年 | 66篇 |
2013年 | 79篇 |
2012年 | 58篇 |
2011年 | 60篇 |
2010年 | 60篇 |
2009年 | 50篇 |
2008年 | 48篇 |
2007年 | 104篇 |
2006年 | 46篇 |
2005年 | 48篇 |
2004年 | 34篇 |
2003年 | 33篇 |
2002年 | 37篇 |
2001年 | 27篇 |
2000年 | 18篇 |
1999年 | 20篇 |
1998年 | 36篇 |
1997年 | 54篇 |
1996年 | 35篇 |
1995年 | 41篇 |
1994年 | 36篇 |
1993年 | 30篇 |
1992年 | 18篇 |
1991年 | 10篇 |
1990年 | 25篇 |
1989年 | 35篇 |
1988年 | 22篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 13篇 |
1977年 | 11篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1968年 | 8篇 |
1966年 | 9篇 |
1965年 | 12篇 |
1963年 | 11篇 |
1959年 | 13篇 |
1956年 | 8篇 |
排序方式: 共有1659条查询结果,搜索用时 250 毫秒
41.
Sun-Seog Kweon Young-Hoon Lee Seul-Ki Jeong Hae-Sung Nam Kyeong-Soo Park Seong-Woo Choi Bok-Hee Kim Hee Nam Kim Jin-Su Choi Min-Ho Shin 《Journal of Korean medical science》2014,29(5):743-747
The reference interval for plasma total homocysteine (tHcy) and serum folate concentrations were estimated. Total of 3,154 reference individuals (1,029 men and 2,125 women) were selected based on stringent exclusion criteria. For plasma tHcy concentration (µM/L), reference values (median [5-95 percentile]) were 7.72 (5.03 to 13.80) and 6.09 (3.95-10.19) in men and women, respectively. For serum folate concentration (nM/L), reference values were 23.71 (11.73-38.44) and 28.95 (15.23-40.44) in men and women, respectively. The tHcy levels of both genders in the present study were lower than those in previous reports from other countries and Korea.
Graphical Abstract
相似文献42.
43.
The molecular circuitries controlling the process of skin wound healing have gained new significant insights in recent years. This knowledge is built on landmark studies on skin embryogenesis, maturation, and differentiation. Furthermore, the identification, characterization, and elucidation of the biological roles of adult skin epithelial stem cells and their influence in tissue homeostasis have provided the foundation for the overall understanding of the process of skin wound healing and tissue repair. Among numerous signaling pathways associated with epithelial functions, the PI3K/Akt/mTOR signaling route has gained substantial attention with the generation of animal models capable of dissecting individual components of the pathway, thereby providing a novel insight into the molecular framework underlying skin homeostasis and tissue regeneration. In this review, we focus on recent findings regarding the mechanisms involved in wound healing associated with the upregulation of the activity of the PI3K/Akt/mTOR circuitry. This review highlights critical findings on the molecular mechanisms controlling the activation of mTOR, a downstream component of the PI3K–PTEN pathway, which is directly involved in epithelial migration and proliferation. We discuss how this emerging information can be exploited for the development of novel pharmacological intervention strategies to accelerate the healing of critical size wounds. 相似文献
44.
Brian P. Cunningham MD Samuel Harmsen MD Chris Kweon MD Jason Patterson MD Robert Waldrop MD Alex McLaren MD Ryan McLemore PhD 《Clinical orthopaedics and related research》2013,471(11):3679-3686
Background
Since 2003 many orthopaedic journals have adopted grading systems for levels of evidence (LOE). It is unclear if the quality of orthopaedic literature has changed since LOE was introduced.Questions/purposes
We asked three questions: (1) Have the overall number and proportion of Level I and II studies increased in the orthopaedic literature since the introduction of LOE? (2) Is a similar pattern seen in individual orthopaedic subspecialty journals? (3) What is the interobserver reliability of grading LOE?Methods
We assigned LOE to therapeutic studies published in 2000, 2005, and 2010 in eight major orthopaedic subspecialty journals. Number and proportion of Level I and II publications were determined. Data were evaluated using log-linear models. Twenty-six reviewers (13 residents and 13 attendings) graded LOE of 20 blinded therapeutic articles from the Journal of Bone and Joint Surgery for 2009. Interobserver agreement relative to the Journal of Bone and Joint Surgery was assessed using a weighted kappa.Results
The total number of Level I and II publications in subspecialty journals increased from 150 in 2000 to 239 in 2010. The proportion of high-quality publications increased with time (p < 0.001). All subspecialty journals other than the Journal of Pediatric Orthopaedics and the Journal of Orthopaedic Trauma showed a similar behavior. Average weighted kappa was 0.791 for residents and 0.842 for faculty (p = 0.209).Conclusions
The number and proportion of Level I and II publications have increased. LOE can be graded reliably with high interobserver agreement. The number and proportion of high-level studies should continue to increase. 相似文献45.
46.
Weaver CH; Buckner CD; Longin K; Appelbaum FR; Rowley S; Lilleby K; Miser J; Storb R; Hansen JA; Bensinger W 《Blood》1993,82(7):1981-1984
Five syngeneic transplants were performed in four patients following myeloablative therapy using unmodified peripheral blood mononuclear cells (PBMCs) collected after the administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) to normal donors. The only toxicity experienced by the four normal donors was bone pain. Four patients received two collections of PBMCs, and a second transplant was performed in one patient with one collection. The patients received a median of 20.53 x 10(8) total nucleated cells/kg (range 20 to 25.5), 11.3 x 10(8) total mononuclear cells/kg (range 6.52 to 17.2), 113.1 x 10(4)/kg CFU-GM (range 46.7 to 211.8) and 9.6 x 10(6) CD34+ cells/kg (range 1.6 to 12.6) Post-transplant growth factors were not administered. The median time to an absolute neutrophil count greater than 0.5 x 10(9)/L was 14 days (range 10 to 18). The median time to platelet transfusion independence was 11 days (range 10 to 13). Two patients had the number of CD3+ T lymphocytes determined in the pheresis product. An average of 3.04 x 10(10) CD3+ cells were collected per pheresis. This represents an approximate 1 log increase over the number of T lymphocytes in a typical bone marrow transplant. Rh-GCSF can be used to mobilize peripheral blood progenitor cells from normal donors with minimal toxicity. Studies of allogeneic transplants using PBMCs collected after rhG-CSF administration to determine permanent grafting ability and the incidence and severity of graft-versus-host disease are warranted. 相似文献
47.
Stem cell factor retards differentiation of normal human erythroid progenitor cells while stimulating proliferation 总被引:5,自引:12,他引:5
Stem cell factor (SCF), the ligand for the c-kit tyrosine kinase receptor, markedly stimulates the accumulation of erythroid progenitor cells in vitro. We now report that SCF delays erythroid differentiation among the progeny of individual erythroid progenitors while greatly increasing the proliferation of these progeny. These effects appear to be independent of an effect on maintenance of cell viability. Highly purified day-6 erythroid colony-forming cells (ECFC), consisting mainly of colony-forming units-erythroid (CFU-E), were generated from human peripheral blood burst-forming units-erythroid (BFU-E). Addition of SCF to the ECFC in serum-free liquid culture, together with erythropoietin (EP) and insulin-like growth factor 1 (IGF-1), resulted in a marked increase in DNA synthesis, associated with a delayed peak in cellular benzidine positivity and a delayed incorporation of 59Fe into hemoglobin compared with cultures without SCF. In the presence of SCF, the number of ECFC was greatly expanded during this culture period, and total production of benzidine-positive cells plus hemoglobin synthesis were ultimately increased. To determine the effect of SCF on individual ECFC, single-cell cultures were performed in both semisolid and liquid media. These cultures demonstrated that SCF, in the presence of EP and IGF-1, acted on single cells and their descendants to delay erythroid differentiation while substantially stimulating cellular proliferation, without an enhancement of viability of the initial cells. This was also evident when the effect of SCF was determined using clones of ECFC derived from single BFU-E. Our experiments demonstrate that SCF acts on individual day-6 ECFC to retard erythroid differentiation while simultaneously providing enhanced proliferation by a process apparently independent of an effect on cell viability or programmed cell death. 相似文献
48.
Song JH Nguyen HH Cuburu N Horimoto T Ko SY Park SH Czerkinsky C Kweon MN 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(5):1644-1649
We assessed whether the sublingual (s.l.) route would be an effective means of delivering vaccines against influenza virus in mice by using either formalin-inactivated or live influenza A/PR/8 virus (H1N1). Sublingual administration of inactivated influenza virus given on two occasions induced both systemic and mucosal antibody responses and conferred protection against a lethal intranasal (i.n.) challenge with influenza virus. Coadministration of a mucosal adjuvant (mCTA-LTB) enhanced these responses and resulted in complete protection against respiratory viral challenge. In addition, s.l. administration of formalin-inactivated A/PR/8 plus mCTA-LTB induced systemic expansion of IFN-gamma-secreting T cells and virus-specific cytotoxic T lymphocyte responses. Importantly, a single s.l. administration of live A/PR/8 virus was not pathogenic and induced protection mediated by both acquired and innate immunity. Moreover, s.l. administration of live A/PR/8 virus conferred heterosubtypic protection against respiratory challenge with H3N2 virus. Unlike the i.n. route, the A/PR/8 virus, whether live or inactivated, did not migrate to or replicate in the CNS after s.l. administration. Based on these promising findings, we propose that the s.l. mucosal route offers an attractive alternative to mucosal routes for administering influenza vaccines. 相似文献
49.
50.
Min-Ho Shin Jin-Su Choi Jung-Ae Rhee Young-Hoon Lee Hae-Sung Nam Seul-Ki Jeong Kyeong-Soo Park Hye-Yeon Kim So-Yeon Ryu Seong-Woo Choi Hee Nam Kim Hye-Rim Song Jane A. Cauley Sun-Seog Kweon 《Atherosclerosis》2014