全文获取类型
收费全文 | 2243篇 |
免费 | 199篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 46篇 |
妇产科学 | 23篇 |
基础医学 | 336篇 |
口腔科学 | 60篇 |
临床医学 | 228篇 |
内科学 | 426篇 |
皮肤病学 | 47篇 |
神经病学 | 254篇 |
特种医学 | 98篇 |
外科学 | 297篇 |
综合类 | 46篇 |
一般理论 | 11篇 |
预防医学 | 191篇 |
眼科学 | 105篇 |
药学 | 144篇 |
中国医学 | 1篇 |
肿瘤学 | 123篇 |
出版年
2021年 | 22篇 |
2020年 | 13篇 |
2019年 | 24篇 |
2018年 | 30篇 |
2017年 | 21篇 |
2016年 | 32篇 |
2015年 | 34篇 |
2014年 | 54篇 |
2013年 | 67篇 |
2012年 | 107篇 |
2011年 | 102篇 |
2010年 | 46篇 |
2009年 | 53篇 |
2008年 | 89篇 |
2007年 | 98篇 |
2006年 | 101篇 |
2005年 | 88篇 |
2004年 | 93篇 |
2003年 | 101篇 |
2002年 | 100篇 |
2001年 | 79篇 |
2000年 | 87篇 |
1999年 | 78篇 |
1998年 | 48篇 |
1997年 | 36篇 |
1996年 | 31篇 |
1995年 | 26篇 |
1994年 | 38篇 |
1993年 | 32篇 |
1992年 | 54篇 |
1991年 | 46篇 |
1990年 | 38篇 |
1989年 | 38篇 |
1988年 | 30篇 |
1987年 | 41篇 |
1986年 | 35篇 |
1985年 | 38篇 |
1984年 | 23篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 16篇 |
1980年 | 21篇 |
1979年 | 35篇 |
1978年 | 33篇 |
1977年 | 18篇 |
1975年 | 20篇 |
1974年 | 23篇 |
1973年 | 24篇 |
1972年 | 14篇 |
1971年 | 14篇 |
排序方式: 共有2448条查询结果,搜索用时 31 毫秒
1.
2.
The impact of the COVID-19 pandemic on radiotherapy services in England,UK: a population-based study
3.
Stem-cell-based tissue engineering of murine teeth 总被引:31,自引:0,他引:31
Teeth develop from reciprocal interactions between mesenchyme cells and epithelium, where the epithelium provides the instructive information for initiation. Based on these initial tissue interactions, we have replaced the mesenchyme cells with mesenchyme created by aggregation of cultured non-dental stem cells in mice. Recombinations between non-dental cell-derived mesenchyme and embryonic oral epithelium stimulate an odontogenic response in the stem cells. Embryonic stem cells, neural stem cells, and adult bone-marrow-derived cells all responded by expressing odontogenic genes. Transfer of recombinations into adult renal capsules resulted in the development of tooth structures and associated bone. Moreover, transfer of embryonic tooth primordia into the adult jaw resulted in development of tooth structures, showing that an embryonic primordium can develop in its adult environment. These results thus provide a significant advance toward the creation of artificial embryonic tooth primordia from cultured cells that can be used to replace missing teeth following transplantation into the adult mouth. 相似文献
4.
JM Palefsky M-E Penaranda LT Pierik LA Lagenaur LA MacPhail D Greenspan JS Greenspan 《Oral diseases》1997,3(Z1):S171-S176
Hairy leukoplakia (HL) is a lesion found on the side of the tongue of immunocompromised individuals, including those with human immunodeficiency virus (HIV) infection. The lesion has unique histopathologic features and is characterised by high-level Epstein-Barr virus (EBV) replication, multiple EBV strains, and extensive inter-and intra-strain recombination. Expression of EBV genes spanning the entire viral life cycle from latency-associated genes to late, replicative genes has been detected in the lesion. HL thus provides a unique opportunity to study EBV expression in oral epithelium, and to study expression of novel EBV genes. We therefore constructed a cDNA library from an HL biopsy and detected expression of two genes not previously described in vivo: BMRF-2 and BDLF-3. Sequence analysis of the cDNAs revealed few amino acid changes from the B95-8 sequence. Expression of both genes was localized to the lower prickle cell layer of the tongue epithelium. BMRF-2 protein expression was primarily detected in the cell nuclei of the upper prickle cell layer. BDLF-3 protein expression was observed in the perinuclear space and Golgi compartment. The function of these proteins is currently under investigation. 相似文献
5.
Total radical trapping antioxidant potential (TRAP) and exercise 总被引:1,自引:0,他引:1
Sharpe PC; Duly EB; MacAuley D; McCrum EE; Mulholland C; Stott G; Boreham CA; Kennedy G; Evans AE; Trinick TR 《QJM : monthly journal of the Association of Physicians》1996,89(3):223-228
The relationship between physical activity, physical fitness and total
radical trapping antioxidant potential (TRAP) was examined in the Northern
Ireland Health and Activity Survey. This was a cross-sectional population
study (n = 1600) using a two-stage probability sample of the population.
TRAP was calculated using the sum of the individual serum antioxidant
concentrations (urate, protein thiols, ascorbate, alpha tocopherol and
bilirubin) multiplied by their respective stoichiometric values. Physical
fitness was determined by estimation of VO2max by extrapolation from
submaximal oxygen uptake, and physical activity was recorded by
computer-assisted interview. Mean serum TRAP concentrations were
significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared
to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female
smokers had significantly lower TRAP values than non-smokers (males p <
0.0001, females p = 0.02). In females, there was a positive relationship of
TRAP with age (p < 0.001) and body mass index (p < 0.001) but a
negative relationship with physical fitness (p < 0.05). The known
beneficial effects of exercise and activity do not appear to be directly
mediated through increased antioxidant status.
相似文献
6.
7.
Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients 总被引:10,自引:0,他引:10
JW Mosley ; CE Stevens ; RD Aach ; FB Hollinger ; LT Mimms ; LR Solomon ; LH Barbosa ; GJ Nemo 《Transfusion》1995,35(1):5-12
BACKGROUND: Testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate for hepatitis C viremia is no longer needed for blood donor screening. Currently, the important question is how much its use supplements hepatitis B surface antigen (HBsAg) donor screening in preventing transfusion-transmitted hepatitis B virus (HBV) infection. STUDY DESIGN AND METHODS: In a study conducted in the 1970s, 64 blood donors were associated with 15 cases of HBV (1.0%) in 1533 transfusion recipients. Sera from 61 donors at donation and 29 follow-up visits were available for present-day assays for HBsAg, HBV DNA, anti-HBc, and antibody to HBsAg (anti-HBs). RESULTS: HBsAg was found in four previously negative blood donors; HBV DNA was limited to three of these four. Anti-HBc was detected in six HBsAg-negative donors. Two other donors were negative in all assays at donation, but positive for anti- HBc and anti-HBs 2 to 4 months later. The remaining donors were negative for all HBV markers, which left five recipient cases unexplained. No HBV transmission was observed when anti-HBs sample-to- negative control values were > or = 10. CONCLUSION: Some 33 to 50 percent of cases of hepatitis B that could be transmitted by transfusion of blood from HBsAg-negative donors are prevented by anti- HBc screening. Anti-HBc-positive donors unequivocally positive for anti- HBs should be considered noninfectious for HBV and should be allowed to donate. Anti-HBc screening of paid plasmapheresis donors, supplemented by anti-HBs testing, would reduce the amount of HBV to be processed by virus inactivation and increase the content of anti-HBs in plasma pools. 相似文献
8.
Elizabeth L Sharpe 《Advances in neonatal care》2008,8(3):150-62; quiz 163-4
Advances in neonatology now support the survival of the tiniest of infants. The peripherally inserted central catheter (PICC) has now become an integral part of routine practice in neonatal intensive care units around the world. Keen attention to safe maintenance of these devices is essential. A properly applied and maintained PICC dressing is the first line of defense to minimize the risk of complications such as dislodgement, migration, and infection. This article describes a neonatal PICC dressing change and discusses the frequently encountered quandaries surrounding this important procedure, including dressing materials, frequency, site preparation, barrier precautions, and other relevant concerns. 相似文献
9.
S. Krid LT. Roumenina D. Beury M. Charbit O. Boyer V. Frémeaux‐Bacchi P. Niaudet 《American journal of transplantation》2012,12(7):1938-1944
We report the first observation of successful kidney transplantation under pre‐emptive eculizumab treatment in a 7‐year‐old boy with atypical hemolytic uremic syndrome (aHUS) and a known hybrid CFH/CFHR1 gene, who was dependent on plasma therapy during the 3‐year dialysis period. The hybrid CFH/CFHR1 protein has an altered C3b/C3d binding, is incapable to protect cells from complement attack and is directly implicated in aHUS pathogenesis. There was no evidence of recurrence during the first 16‐month follow‐up period. We conclude that eculizumab alone, without plasma therapy (plasma infusion and/or plasma exchange), is sufficient to prevent recurrence of aHUS and to maintain long‐term graft function. 相似文献
10.
Sharpe JP Magnotti LJ Weinberg JA Parks NA Maish GO Shahan CP Fabian TC Croce MA 《Journal of the American College of Surgeons》2012,214(4):591-7; discussion 597-8