全文获取类型
收费全文 | 1837篇 |
免费 | 166篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 131篇 |
妇产科学 | 22篇 |
基础医学 | 183篇 |
口腔科学 | 53篇 |
临床医学 | 274篇 |
内科学 | 359篇 |
皮肤病学 | 18篇 |
神经病学 | 58篇 |
特种医学 | 223篇 |
外科学 | 273篇 |
综合类 | 46篇 |
一般理论 | 2篇 |
预防医学 | 140篇 |
眼科学 | 49篇 |
药学 | 99篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 80篇 |
出版年
2021年 | 11篇 |
2019年 | 16篇 |
2018年 | 23篇 |
2017年 | 28篇 |
2016年 | 18篇 |
2015年 | 34篇 |
2014年 | 42篇 |
2013年 | 51篇 |
2012年 | 50篇 |
2011年 | 47篇 |
2010年 | 55篇 |
2009年 | 60篇 |
2008年 | 55篇 |
2007年 | 26篇 |
2006年 | 43篇 |
2005年 | 38篇 |
2004年 | 38篇 |
2003年 | 34篇 |
2002年 | 50篇 |
2001年 | 33篇 |
2000年 | 28篇 |
1999年 | 46篇 |
1998年 | 99篇 |
1997年 | 99篇 |
1996年 | 102篇 |
1995年 | 66篇 |
1994年 | 64篇 |
1993年 | 55篇 |
1992年 | 61篇 |
1991年 | 52篇 |
1990年 | 24篇 |
1989年 | 49篇 |
1988年 | 39篇 |
1987年 | 56篇 |
1986年 | 38篇 |
1985年 | 47篇 |
1984年 | 32篇 |
1983年 | 30篇 |
1982年 | 18篇 |
1981年 | 22篇 |
1980年 | 17篇 |
1979年 | 16篇 |
1978年 | 19篇 |
1977年 | 20篇 |
1976年 | 20篇 |
1975年 | 16篇 |
1973年 | 12篇 |
1972年 | 13篇 |
1969年 | 10篇 |
1966年 | 11篇 |
排序方式: 共有2014条查询结果,搜索用时 15 毫秒
51.
PJ Nelemans NWJ Kelleners‐Smeets 《Journal of the European Academy of Dermatology and Venereology》2011,25(5):565-569
Background As a result of the high prevalence, basal cell carcinoma (BCC) causes a significant and expensive health care problem. Objective In this study, we evaluate the proportional increase in BCC by histological subtype over the last two decades. Methods We retrospectively reviewed all primary histological confirmed BCCs diagnosed in the Maastricht University Medical Centre in The Netherlands in the years 1991, 1999 and 2007. Results An annual increase of the number of BCCs of 7% for both genders was shown. The age‐standardized incidence rates for BCC increased between 1991 and 2007 from 54.2 to 162.1 per 100 000 men and from 61.7 to 189.8 per 100 000 women. The proportion of superficial BCC increased significantly from 17.6% to 30.7%. Conclusion The incidence of BCC is continuing to increase this century. The observed shift to the superficial histological subtype, which can be treated non‐surgically, might reduce the workload in the busy dermatologists practice. 相似文献
52.
53.
Acute lymphoblastic leukemia (ALL) is one of the most common cancer diagnoses identified in adolescents and young adults (AYAs). Although most children with ALL are cured of their disease, AYAs have experienced much worse outcomes over time, with event-free survival ranging from 30 to 45%. This survival disparity is likely due to differences in tumor biology, treatment-related toxicities, and nonmedical issues. This review summarizes these differences as well as focusing on the various trials that have demonstrated superior outcomes with pediatric protocols in AYAs with ALL. Even with the widespread use of these protocols, a treatment gap remains, and novel therapies are one way to address this problem. Still, these therapies also have significant toxicities and unique issues that need to be tested further, especially in the AYA population. The development of more AYA-specific trials will be an important way to examine novel therapies and interventions designed to reduce treatment-related toxicities and improve long-term outcomes. 相似文献
54.
55.
56.
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57.
Differential effects of nitric oxide on erythroid and myeloid colony growth from CD34+ human bone marrow cells 总被引:15,自引:0,他引:15
Nitric oxide (NO) is a reactive molecule with numerous physiologic and pathophysiologic roles affecting the nervous, cardiovascular, and immune systems. In previous work, we have demonstrated that NO inhibits the growth and induces the monocytic differentiation of cells of the HL- 60 cell line. We have also demonstrated that NO inhibits the growth of acute nonlymphocytic leukemia cells freshly isolated from untreated patients and increases monocytic differentiation antigens in some. In the present work, we studied the effect of NO on the growth and differentiation of normal human bone marrow cells in vitro. Mononuclear cells isolated from human bone marrow were cultured in semisolid media and treated with the NO-donating agents sodium nitroprusside (SNP) or S- nitroso-acetyl penicillamine (SNAP) (0.25 to 1 mmol/L). Both agents decreased colony-forming unit-erythroid (CFU-E) and colony-forming unit- granulocyte macrophage (CFU-GM) formation by 34% to 100%. When CD34+ cells were examined, we noted that these cells responded to SNP and SNAP differently than did the mononuclear cells. At a concentration range of 0.25 to 1 mmol/L, SNP inhibited the growth of CFU-E by 30% to 75%. However, at the same concentration range, SNP increased the number of CFU-GM by up to 94%. At concentrations of 0.25 to 1 mmol/L, SNAP inhibited the growth of CFU-E by 33% to 100%. At a concentration of 0.25 mmol/L, SNAP did not affect CFU-GM. At higher concentrations, SNAP inhibited the growth of CFU-GM. Although SNP increased intracellular levels of cGMP in bone marrow cells, increasing cGMP in cells by addition of 8-Br-cGMP (a membrane permeable cGMP analogue) did not reproduce the observed NO effects on bone marrow colonies. These results demonstrate that NO can influence the growth and differentiation of normal human bone marrow cells. NO (generated in the bone marrow microenvironment) may play an important role modulating the growth and differentiation of bone marrow cells in vivo. 相似文献
58.
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
59.
Air-driven nebulised high-dose salbutamol in severe chronic obstructive airways disease: is it safe?
C K Lai J S Legge J A Friend 《Respiration; international review of thoracic diseases》1991,58(5-6):249-254
The increasing use of air-driven nebulised bronchodilators by patients with airflow obstruction has raised concern about the safety of this practice. We have investigated the effects of 10 mg salbutamol, nebulised in air, on blood gas tensions, heart rate and plasma potassium (K+), when administered alone to 9 patients with severe chronic obstructive airway disease and then in combination with a therapeutic dose of oral sustained-release theophylline to 5 of them on 2 separate occasions. No significant reductions in PaO2 were observed with either treatments. Heart rate increased significantly from 77.8 +/- 3.7 beats/min (mean +/- s.e.m.) at baseline to a peak of 87.1 +/- 4.4 beats/min at 45 min (p less than 0.001) with salbutamol alone and there was a similar trend of increase after combined therapy. K+ decreased significantly from a baseline of 4.0 +/- 0.3 to a minimum of 3.6 +/- 0.2 mmol/l at 90 min (p less than 0.001) with combined therapy but did not change significantly with single therapy. No subject developed any significant cardiac arrhythmias on either occasion. Although the number of subjects studied is small, our data suggest that air-driven nebulised high-dose salbutamol may be safe in the treatment of severe chronic obstructive airway disease but when combined with oral theophylline, a significant fall in plasma potassium may occur. This could be of clinical significance in hypokalaemic patients. When combination treatment is used, monitoring of plasma potassium is recommended. 相似文献
60.
Ivan J. Fuss Julia Friend Zhiqiong Yang Jian Ping He Lubna Hooda James Boyer Liqiang Xi Mark Raffeld David E. Kleiner Theo Heller Warren Strober 《Journal of clinical immunology》2013,33(4):748-758