全文获取类型
收费全文 | 2897篇 |
免费 | 224篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 103篇 |
妇产科学 | 227篇 |
基础医学 | 368篇 |
口腔科学 | 51篇 |
临床医学 | 443篇 |
内科学 | 514篇 |
皮肤病学 | 134篇 |
神经病学 | 151篇 |
特种医学 | 128篇 |
外科学 | 420篇 |
综合类 | 104篇 |
一般理论 | 3篇 |
预防医学 | 286篇 |
眼科学 | 22篇 |
药学 | 179篇 |
中国医学 | 3篇 |
肿瘤学 | 73篇 |
出版年
2021年 | 25篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 32篇 |
2017年 | 42篇 |
2016年 | 34篇 |
2015年 | 36篇 |
2014年 | 76篇 |
2013年 | 109篇 |
2012年 | 126篇 |
2011年 | 144篇 |
2010年 | 78篇 |
2009年 | 87篇 |
2008年 | 111篇 |
2007年 | 152篇 |
2006年 | 121篇 |
2005年 | 109篇 |
2004年 | 98篇 |
2003年 | 91篇 |
2002年 | 63篇 |
2001年 | 97篇 |
2000年 | 83篇 |
1999年 | 72篇 |
1998年 | 68篇 |
1997年 | 70篇 |
1996年 | 55篇 |
1995年 | 55篇 |
1994年 | 47篇 |
1993年 | 36篇 |
1992年 | 67篇 |
1991年 | 53篇 |
1990年 | 60篇 |
1989年 | 66篇 |
1988年 | 60篇 |
1987年 | 45篇 |
1986年 | 53篇 |
1985年 | 44篇 |
1984年 | 41篇 |
1983年 | 39篇 |
1982年 | 20篇 |
1981年 | 22篇 |
1978年 | 26篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1975年 | 22篇 |
1974年 | 27篇 |
1973年 | 23篇 |
1972年 | 17篇 |
1968年 | 16篇 |
1966年 | 22篇 |
排序方式: 共有3212条查询结果,搜索用时 15 毫秒
71.
Neumann M Wirtz M Bollschweiler E Mercer SW Warm M Wolf J Pfaff H 《Patient education and counseling》2007,69(1-3):63-75
OBJECTIVE: The aim of the present cross-sectional study was to explore patient- and physician-specific determinants of physician empathy (PE) and to analyse the influence of PE on patient-reported long-term outcomes in German cancer patients. METHODS: A postal survey was administered to 710 cancer patients, who had been inpatients at the University Hospital Cologne (response rate 49.5%). PE was measured with the German translation of the consultation and relational empathy (CARE) measure, and patient-reported long-term outcomes were assessed using the major (ICD-10) depression inventory (MDI) and the EORTC quality of life (Qol) questionnaire QLQ-C30. Hypotheses were tested by structural equation modelling. RESULTS: PE had (a) a moderate indirect effect on "depression" and a smaller indirect effect on "socio-emotional-cognitive Qol" by affecting "desire for more information from the physician regarding findings and treatment options" and (b) a moderate indirect effect on "socio-emotional-cognitive Qol" and a smaller effect on "depression" via "desire for more information about health promotion". The determinant with the greatest importance was "patient-perceived general busyness of hospital staff": it had a strong negative influence on PE, indirectly influencing "desire for more information from the physician regarding findings and treatment options" and also patients' "depression". CONCLUSION: PE seems to be an important pre-requisite for information giving by physicians and through this pathway having a preventive effect on depression and improving Qol. Conversely, physicians' stress negatively influences these relationships. PRACTICE IMPLICATIONS: The research findings suggest that reducing physicians' stress at the organizational and individual may be required to enhance patient-physician communication. Empathy, as an outcome-relevant professional competence needs to be assessed and developed more intensively in medical students and physicians. 相似文献
72.
Rouse DJ Caritis SN Peaceman AM Sciscione A Thom EA Spong CY Varner M Malone F Iams JD Mercer BM Thorp J Sorokin Y Carpenter M Lo J Ramin S Harper M Anderson G;National Institute of Child Health Human Development Maternal-Fetal Medicine Units Network 《The New England journal of medicine》2007,357(5):454-461
73.
Paul D. Hayes Keith G. Harding Susan M. Johnson Charles McCollum Luc Tot Kevin Mercer David Russell 《International wound journal》2020,17(3):742-752
Venous leg ulcers (VLUs) have a significant impact on approximately 3% of the adult population worldwide, with a mean NHS wound care cost of £7600 per VLU over 12 months. The standard care for VLUs is compression therapy, with a significant number of ulcers failing to heal with this treatment, especially with wound size being a risk factor for non‐healing. This multicentre, prospective, randomised trial evaluated the safety and effectiveness of autologous skin cell suspension (ASCS) combined with compression therapy compared with standard compression alone (Control) for the treatment of VLUs. Incidence of complete wound closure at 14 weeks, donor site closure, pain, Health‐Related Quality of Life (HRQoL), satisfaction, and safety were assessed in 52 patients. At Week 14, VLUs treated with ASCS + compression had a statistically greater decrease in ulcer area compared with the Control (8.94 cm2 versus 1.23 cm2, P = .0143). This finding was largely driven by ulcers >10 to 80 cm2 in size, as these ulcers had a higher mean percentage of reepithelialization at 14 weeks (ASCS + compression: 69.97% and Control: 11.07%, P = .0480). Additionally, subjects treated with ASCS + compression experienced a decrease in pain and an increase in HRQoL compared with the Control. This study indicates that application of ASCS + compression accelerates healing in large venous ulcers. 相似文献
74.
75.
76.
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
77.
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
78.
David W. Mercer James M. Cross Lily Chang Lenard M. Lichtenberger 《Digestive diseases and sciences》1998,43(4):826-833
Bombesin or gastrin-releasing peptide preventsgastric injury by an unknown mechanism. Since exogenousgastrin is a gastroprotective agent, this study wasundertaken to test the hypothesis that gastroprotection by bombesin involves release of endogenousgastrin. Subcutaneous bombesin (10-100 g/kg) dosedependently reduced macroscopic injury to theacid-secreting portion of the stomach caused by 1 ml oforogastric acidified ethanol (150 mM hydrochloric acid-50%ethanol). Blockade of type A cholecystokinin receptorswith intraperitoneal MK-329 (1 mg/kg) reversedintravenous cholecystokinin (5 nmol/kg)-inducedgastroprotection, but not that of bombesin. In contrast,intraperitoneal type B cholecystokinin (gastrin)receptor blockade with L-365,260 (25 mg/kg) diminishedthe protective actions of both subcutaneous bombesin(100 mug/kg) and intravenous gastrin (25 pmol/kg). Inadditional studies, subcutaneous bombesin (10-100g/kg) dose dependently increased serum gastrinlevels (radioimmunoassay). Both the gastroprotectiveactions of bombesin and bombesininduced gastrin releasewere enhanced following immunoneutralization ofendogenous somatostatin with intraperitonealsomatostatin antibody (2 mg). These data indicate thatbombesin prevents gastric injury primarily by release ofendogenous gastrin and both effects are modified byendogenous somatostatin. 相似文献
79.
Primary structure of the (1-->3,1-->4)-beta-D-glucan 4-glucohydrolase from barley aleurone 下载免费PDF全文
Fincher GB Lock PA Morgan MM Lingelbach K Wettenhall RE Mercer JF Brandt A Thomsen KK 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(7):2081-2085
During germination of barley grains, the cell walls of the starchy endosperm are degraded by (1→3,1→4)-β-glucanases (EC 3.2.1.73) secreted from the aleurone and scutellar tissues. The complete sequence of the aleurone (1→3,1→4)-β-glucanase isoenzyme II comprises 306 amino acids and was determined by sequencing nine tryptic peptides (110 residues) and aligning them with the amino acid sequence deduced from a cDNA clone encoding the 291 NH2-terminal residues. Although no amino acid sequence homology with a bacterial (1→3)(1→4)-β-glucanase is apparent, close to 50% homology is found with two large regions of a (1→3)-β-glucanase from tobacco pith tissue. The gene for barley (1→3,1→4)-β-glucanase isoenzyme II shares with that for the α-amylase isoenzyme 1 a strongly preferred use of codons with G and C in the wobble position (94% and 90%, respectively). Both enzymes are secreted from the aleurone cells during germination. Such one-sided codon usage is not characteristic for the gene encoding the (1→3)-β-glucanase of tobacco pith tissue or the hor2-4 gene encoding the B1 hordein storage protein in the endosperm. 相似文献