全文获取类型
收费全文 | 1809篇 |
免费 | 164篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 123篇 |
妇产科学 | 15篇 |
基础医学 | 227篇 |
口腔科学 | 39篇 |
临床医学 | 260篇 |
内科学 | 351篇 |
皮肤病学 | 18篇 |
神经病学 | 92篇 |
特种医学 | 230篇 |
外科学 | 199篇 |
综合类 | 53篇 |
一般理论 | 1篇 |
预防医学 | 110篇 |
眼科学 | 151篇 |
药学 | 70篇 |
1篇 | |
肿瘤学 | 43篇 |
出版年
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 23篇 |
2018年 | 28篇 |
2017年 | 23篇 |
2016年 | 24篇 |
2015年 | 32篇 |
2014年 | 35篇 |
2013年 | 38篇 |
2012年 | 53篇 |
2011年 | 52篇 |
2010年 | 66篇 |
2009年 | 62篇 |
2008年 | 69篇 |
2007年 | 61篇 |
2006年 | 63篇 |
2005年 | 61篇 |
2004年 | 46篇 |
2003年 | 45篇 |
2002年 | 41篇 |
2001年 | 41篇 |
2000年 | 53篇 |
1999年 | 41篇 |
1998年 | 89篇 |
1997年 | 95篇 |
1996年 | 99篇 |
1995年 | 71篇 |
1994年 | 58篇 |
1993年 | 52篇 |
1992年 | 40篇 |
1991年 | 35篇 |
1990年 | 27篇 |
1989年 | 50篇 |
1988年 | 44篇 |
1987年 | 45篇 |
1986年 | 33篇 |
1985年 | 38篇 |
1984年 | 26篇 |
1983年 | 25篇 |
1982年 | 20篇 |
1981年 | 20篇 |
1980年 | 12篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1976年 | 14篇 |
1975年 | 11篇 |
1971年 | 9篇 |
1970年 | 8篇 |
1969年 | 8篇 |
排序方式: 共有1985条查询结果,搜索用时 15 毫秒
31.
Marsh JC; Will AJ; Hows JM; Sartori P; Darbyshire PJ; Williamson PJ; Oscier DG; Dexter TM; Testa NG 《Blood》1992,79(12):3138-3144
We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse. 相似文献
32.
33.
Saskia PJ Verkleij Pim AJ Luijsterburg Sten P Willemsen Bart W Koes Arthur M Bohnen Sita MA Bierma-Zeinstra 《The British journal of general practice》2015,65(637):e530-e537
Background
The effectiveness of diclofenac versus paracetamol in primary care patients with pain caused by knee osteoarthritis is unclear.Aim
To assess the effectiveness of diclofenac compared with paracetamol over a period of 2, 4, and 12 weeks in patients with knee osteoarthritis.Design and setting
Randomised controlled trial in general practice.Method
There were 104 patients included in the study, they were aged ≥45 years consulting their GP with knee pain caused by knee osteoarthritis. Patients were randomly allocated to diclofenac (n = 52) or paracetamol (n = 52) for at least 2 weeks. Primary outcomes were daily knee pain severity, and knee pain and function measured with the Knee Injury and Osteoarthritis Outcome Score (KOOS).Results
Over a period of 2- and 4-weeks follow-up, no significant difference in daily knee pain was found between the patient groups: estimated differences of 0.5 (95% CI = −0.2 to 1.3) and −0.2 (95% CI = −1.0 to 0.7), respectively. Over the 12-weeks follow-up, no significant differences were found between both groups for KOOS pain: estimated difference of −2.8 (95% CI = −10.7 to 5.1) and KOOS function of −2.7 (−10.6 to 5.0).Conclusion
Over a period of 2- and 4-weeks follow-up no significant difference in daily measured knee pain severity was found between primary care patients with knee osteoarthritis taking paracetamol or diclofenac. Also, over a period of 12-weeks follow-up no significant differences were found regarding KOOS pain and KOOS function between both groups. Patients more frequently reported minor adverse events after taking diclofenac (64%) than paracetamol (46%). 相似文献34.
Computerised cognitive training programs improved the cognitive performance of healthy older adults on some cognitive tests including memory,speed of information processing and visuospatial skills 下载免费PDF全文
35.
Coakley G; Mok CC; Hajeer AH; Ollier WE; Turner D; Sinnott PJ; Hutchinson IV; Panayi GS; Lanchbury JS 《Rheumatology (Oxford, England)》1998,37(9):988-991
OBJECTIVE: To examine whether promoter polymorphisms associated with
variation in interleukin-10 (IL-10) production are relevant to the
development of rheumatoid arthritis (RA) or Felty's syndrome (FS). METHODS:
DNA was obtained from 44 FS patients, 117 RA patients and 295 controls. The
promoter region between -533 and - 1120 was amplified by polymerase chain
reaction, and polymorphisms detected by restriction enzyme digest or
sequence-specific oligonucleotide probing. RESULTS: We found no significant
difference in allele or haplotype frequencies between the groups.
CONCLUSION: There is no association between FS or RA and these recently
identified IL-10 promoter polymorphisms. Other genetic or environmental
factors could explain the alterations in IL-10 levels seen in these
conditions.
相似文献
36.
D S Baldwin J Lowenstein N F Rothfield G Gallo R T McCluskey 《Annals of internal medicine》1970,73(6):929-942
37.
Isolation of cDNA encoding a newly identified major allergenic protein of rye-grass pollen: intracellular targeting to the amyloplast. 下载免费PDF全文
M B Singh T Hough P Theerakulpisut A Avjioglu S Davies P M Smith P Taylor R J Simpson L D Ward J McCluskey et al. 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(4):1384-1388
We have identified a major allergenic protein from rye-grass pollen, tentatively designated Lol pIb of 31kDa and with pI 9.0. A cDNA clone encoding Lol pIb has been isolated, sequenced, and characterized. Lol pIb is located mainly in the starch granules. This is a distinct allergen from Lol pI, which is located in the cytosol. Lol pIb is synthesized in pollen as a pre-allergen with a transit peptide targeting the allergen to amyloplasts. Epitope mapping of the fusion protein localized the IgE binding determinant in the C-terminal domain. 相似文献
38.
Plant sterols as cholesterol-lowering agents: clinical trials in patients with hypercholesterolemia and studies of sterol balance 总被引:9,自引:0,他引:9
We have evaluated the efficacy of plant sterol preparations from two different sources and in two different physical forms in lowering the plasma cholesterol of a total of 46 patients with type II hyperlipoproteinemia when given in addition to appropriate diet therapy. In addition, the mechanisms of the hypocholesterolemic effect were investigated in 7 patients by a sterol balance technique. The maximal mean cholesterol lowering in response to any preparation was 12 percent, although it was much greater in some individual patients. Sterol balance data showed that plant sterols inhibit cholesterol absorption with maximal negative cholesterol balance in adults at a dose of 3 g/day of a tall oil sterol suspension. Interestingly, maximal plasma cholesterol reduction in the adult outpatients on this preparation was seen at the same dose level. Since the tall oil sterol suspension is relatively palatable and is poorly absorbed, it has potential value as an adjunct to dietary therapy in patients with mild hypercholesterolemia for whom long-term drug therapy is deemed advisable. 相似文献
39.
Margaret McGrath Michelle Anne Low Emma Power Annie McCluskey Sandra Lever 《Archives of physical medicine and rehabilitation》2021,102(5):999-1010
ObjectiveTo systematically review health care professionals’ practices and attitudes toward addressing sexuality with people who are living with chronic disease and disability.Data SourcesScopus, PubMed, PsycINFO, Cumulative Index to Nursing and Allied Health, Allied and Complementary Medicine Database, and MEDLINE were searched to August 2020 for English language publications. Reference lists of relevant publications were also searched.Study SelectionEligible studies reported on knowledge, attitudes, and behaviors of health care professionals about addressing sexuality in the context of chronic disease and disability. The search yielded 2492 records; 187 full texts were assessed for eligibility and 114 documents were included (103 unique studies). Study quality was rated using the Mixed Methods Appraisal Tool.Data ExtractionCharacteristics of included studies were recorded independently by 2 authors. Differences were resolved through discussion or by a third author.Data SynthesisA sequential, exploratory mixed studies approach was used for synthesis. Pooled analysis showed that 14.2% (95% CI, 10.6-18.9 [I2=94.8%, P<.001]) of health professionals report routinely asking questions or providing information about sexuality. Professionals reported limited confidence, competence, and/or comfort when initiating conversations about sexuality or responding to patient questions. Sexual rehabilitation typically focused on the effect of disease, disability, and medication on sexual function. Broader dimensions of sexuality were rarely addressed.ConclusionDespite recognizing the value of sexuality to health and well-being, most health professionals regardless of clinical context fail to routinely include assessment of sexuality in their practice. Professionals have limited knowledge and confidence when addressing sexuality and experience significant discomfort when raising this topic with people living with chronic disease and disability. Multicomponent implementation programs are needed to improve health professionals’ knowledge, competence, and comfort when addressing sexuality for people living with chronic disease and disability. 相似文献
40.
A statistical analysis of murine stem cell suicide techniques 总被引:1,自引:0,他引:1
The clinical application of soft agar cloning techniques for granulocyte-macrophage stem cells (CFU-C) has resulted in a number of contradictory reports that may in part be due to an inadequate data base. Growth of murine CFU-C is more reproducible and less variable than that of human CFU-C. We utilized in vivo hydroxyurea suicide of murine marrow CFU-C to address the question of how many experiments are needed to detect a specific difference with a p of less than 0.05. In 66 experiments the mean marrow CFU-C hydroxyurea kill was 23.3%; 6-9 separate experiments were necessary to detaect differences of 25%-30%. In order to be sure that a 25%-30% difference is not present, 15-21 experiments were required. Using a Dec-20 computer, 1000 samples of sample size 3, 4, or 10 were drawn from the 66 experiments; it was found that with 3 experiments and a true value of 23%, the actually observed value was below 10%, 17% of the time, and was over 40% in 10% of the samplings. In a smaller number of experiments similar results were obtained analyzing 3HTdR suicide of pluripotent stem cells and CFU- C. These data could provide a base from which to judge the validity of studies utilizing the CFU-C technique. 相似文献