全文获取类型
收费全文 | 1598篇 |
免费 | 55篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 61篇 |
妇产科学 | 17篇 |
基础医学 | 152篇 |
口腔科学 | 69篇 |
临床医学 | 200篇 |
内科学 | 363篇 |
皮肤病学 | 38篇 |
神经病学 | 56篇 |
特种医学 | 307篇 |
外科学 | 139篇 |
综合类 | 42篇 |
一般理论 | 1篇 |
预防医学 | 86篇 |
眼科学 | 35篇 |
药学 | 84篇 |
中国医学 | 7篇 |
肿瘤学 | 52篇 |
出版年
2023年 | 13篇 |
2022年 | 22篇 |
2021年 | 37篇 |
2020年 | 23篇 |
2019年 | 29篇 |
2018年 | 31篇 |
2017年 | 34篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 58篇 |
2012年 | 62篇 |
2011年 | 61篇 |
2010年 | 56篇 |
2009年 | 75篇 |
2008年 | 57篇 |
2007年 | 91篇 |
2006年 | 65篇 |
2005年 | 52篇 |
2004年 | 33篇 |
2003年 | 30篇 |
2002年 | 33篇 |
2001年 | 24篇 |
2000年 | 24篇 |
1999年 | 12篇 |
1998年 | 87篇 |
1997年 | 75篇 |
1996年 | 61篇 |
1995年 | 51篇 |
1994年 | 43篇 |
1993年 | 45篇 |
1992年 | 23篇 |
1991年 | 17篇 |
1990年 | 22篇 |
1989年 | 37篇 |
1988年 | 36篇 |
1987年 | 28篇 |
1986年 | 25篇 |
1985年 | 23篇 |
1984年 | 21篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1975年 | 13篇 |
1900年 | 2篇 |
排序方式: 共有1731条查询结果,搜索用时 15 毫秒
41.
Corzo D; Yunis JJ; Salazar M; Lieberman JA; Howard A; Awdeh Z; Alper CA; Yunis EJ 《Blood》1995,86(10):3835-3840
Genes of the major histocompatibility complex (MHC) have been associated with susceptibility to drug-induced adverse reactions. We previously found that clozapine-induced agranulocytosis (CA) is associated with the HLA-DRB1*0402, DRB4*0101, DQB1*0302, DQA1*0301 haplotype in Ashkenazi Jewish patients and with the HLA-DRB1*1601, DRB5*02, DQB1*0502, DQA1*0102 haplotype in non-Jewish patients. In the present study, we tested the hypothesis that the variants of the heat- shock protein 70 (HSP-70) encoded by the HSP-70 loci located within the MHC region and known to be involved in apoptosis and regulation of cell proliferation could play an important role in molecular mechanisms of CA. First, we analyzed HSP70-2 polymorphism in risk-associated haplotypes from HLA homozygous cells and normal individuals and confirmed that the HSP70-2 9-kb variant was associated invariably with DR4 (HLA-DRB1*0402, DQB1*0302) and DR2 (HLA-DRB1*01601, DQB1*0502, DQA1*0102 and HLA-DRB1*1501, DQB1*0602) haplotypes, which were the haplotypes found increased in Jewish and non-Jewish patients with CA, respectively. The 9.0-kb variant was also found to be associated with HLA-B44, DRB1*0401 and HLA-B44, DRB1*07 haplotypes. Second, in patients with CA (12 Ashkenazi Jewish and 20 non-Jewish patients), HSP70-1 A and HSP70-2 9.0-kb variants were associated with the MHC haplotypes found by us to be markers of susceptibility to CA. The clozapine-treated control group had an excess number of HSP70-1 C and HSP70-2 8.5-kb variants, consistent with genetic resistance to CA associated with those variants. This finding supports our hypothesis that a dominant gene within the MHC region (marked by HSP70-1 and HSP70-2), but not necessarily HLA, is associated with CA in two different ethnic groups. 相似文献
42.
Majid Haghjoo MD Mehrdad Saravi MD Mohammad Jafar Hashemi MD Saeid Hosseini MD Nader Givtaj MD Mohammad Hassan Ghafarinejad MD Amir Jamshid Khamoushi MD Zahra Emkanjoo MD Amir Farjam Fazelifar MD Abolfath Alizadeh MD Mohammad Ali Sadr-Ameli MD 《Heart rhythm》2007,4(9):1170-1174
BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass graft (CABG) surgery. It has been shown that prophylactic oral beta-blocker administration reduces the incidence of post-CABG AF. However, the optimal beta-blocker has not been identified. OBJECTIVE: This study sought to determine whether oral carvedilol (with its unique anti-inflammatory and antioxidant properties) is more effective than oral metoprolol for prevention of AF after CABG surgery. METHODS: Between April 2006 and December 2006, 120 patients (63 men, mean age 61 +/- 9.4 years) who were scheduled to undergo their first on-pump CABG were enrolled in this study. The patients were randomized in a prospective 1:1 manner to receive either oral carvedilol (n = 60) or oral metoprolol (n = 60). The end point of the study was the occurrence of the new-onset AF during the first 5 days after CABG. RESULTS: AF occurred in 29 of 120 patients (24.0%). The incidence of postoperative AF was 15.0% (9 of 60) in the carvedilol group and 33% (20 of 60) in the metoprolol group (P = .022). The carvedilol group was treated with mean daily dose of 46 +/- 9 mg and metoprolol group with mean daily dose of 93 +/- 11 mg. There were no differences between the study groups regarding any known preoperative, perioperative, or postoperative characteristics (all values were P >.05). No significant adverse effect was observed in either group. CONCLUSION: This prospective study suggested that oral carvedilol is more effective than oral metoprolol in the prevention of AF after on-pump CABG. It is well tolerated when started before and continued after the surgery. However, further prospective studies are needed to clarify this issue. 相似文献
43.
44.
Jafar Soltani Bahram Nikkhoo Jabar Khormehr Pedram Ataee Mohammad-Saeid Hakhamaneshi Fardin Gharibi 《Iranian journal of pediatrics.》2014,24(6):745-752
Objective:
Helicobacter pylori (H. pylori) is the most common chronic bacterial infection in humans. Chronic colonization increases the risk of duodenal ulcer and gastric cancer. The risk factors for acquiring the infection have been extensively studied. However, there are conflicting results on the role of breastfeeding in the prevention of H. pylori infection. We conducted a study to evaluate the effects of breastfeeding on the H. Pylori infection in Kurdish children in Sanandaj, IR Iran.Methods:
A historical cohort study was carried out from January 2011 through December 2012. Totally 221 children who were going to attain 2 years old during the study period were randomly enrolled. They were divided into two groups, i.e. breastfed and non-breastfed. We used H. pylori stool antigen test to detect infection in the selected group of children after age of 2 years and cessation of breastfeeding. Each group was subdivided into two subgroups, infected and non-infected. The associations of breastfeeding with H. pylori infection was assessed using statistical software.Findings:
We found no difference in the odds of infection between breastfed and non-breastfed groups (OR=0.809, 95% CI [0.453–1.444]). An association between age and the prevalence of infection was found (P=0.008). There was an increase in the odds of infection as the family size grew (OR=1.93, 95% CI [1.04–3.6]) as well as increasing housing density (OR=2.12, 95% CI [1.10–4.10]).Conclusion:
The data suggests that breastfeeding in infancy does not protect against H. pylori infection for long duration among studied children in Iran. The protective effects of breastfeeding, if any, are at most transient. 相似文献45.
A Mocroft B Neesgard R Zangerle A Rieger A Castagna V Spagnuolo A Antinori FC Lampe M Youle JJ Vehreschild C Mussini V Borghi J Begovac C Duvivier HF Gunthard A Rauch J Tiraboschi N Chkhartishvili N Bolokadze F Wit JC Wasmuth S De Wit C Necsoi C Pradier V Svedhem C Stephan K Petoumenos H Garges F Rogatto L Peters L Ryom 《HIV medicine》2020,21(9):599-606
46.
Alyasiri NS Mehdi SJ Alam MS Ali A Mandal AK Gupta S Singh I Rizvi MM 《Journal of cancer research and clinical oncology》2012,138(1):103-109
Purpose
The tumor suppressor gene PTEN negatively regulates Akt, a downstream mediator phosphoinositol 3-kinase. Several studies have reported the role of PTEN gene in Akt downregulation and apoptosis induction in different cancers and cell lines. However, the role of loss of PTEN expression in Akt activation and spontaneous apoptosis in oral squamous cell carcinoma clinical specimens is not well established. 相似文献47.
Vincent JJ Odekerken Teus van Laar Michiel J Staal Arne Mosch Carel FE Hoffmann Peter CG Nijssen Guus N Beute Jeroen PP van Vugt Mathieu WPM Lenders M Fiorella Contarino Marieke SJ Mink Lo J Bour Pepijn van den Munckhof Ben A Schmand Rob J de Haan P Richard Schuurman Rob MA de Bie 《Lancet neurology》2013,12(1):37-44
48.
Chunhua Luo Warren J. Grigsby Neil R. Edmonds Jafar Al-Hakkak 《Acta biomaterialia》2013,9(2):5226-5233
Totally bio-based thermosetting polymers which are comparable to synthetic polyester thermosets have been prepared from copolymerization of condensed tannin–fatty acid esters with vegetable oils. Oxidative copolymerization of tannin linoleate/acetate mixed esters with linseed oil and tung oil produced polymer films ranging from soft rubbers to rigid thermosets. Tannin incorporation into the formulations was essential for the final product to achieve necessary mechanical strength. Films had ambient modulus values between 0.12 and 1.6 GPa, with glass transition temperatures ranging from 32 to 72 °C and calculated crosslink densities of 1020–57,700 mol m?3. Film stiffness, Tg and crosslink density increase with greater tannin linoeate/acetate content due mainly to this tannin component providing rigidity through polyphenolic aromatic rings and unsaturated chains as crosslinking sites. 相似文献
49.
Mohseni Rashin Hamidieh Amir Ali Shoae-Hassani Alireza Ghahvechi-Akbari Masood Majma Anahita Mohammadi Mahmoud Nikougoftar Mahin Shervin-Badv Reza Ai Jafar Montazerlotfelahi Hadi Ashrafi Mahmoud Reza 《Neurological sciences》2022,43(1):399-410
Neurological Sciences - Spinal muscular atrophy (SMA), an autosomal recessive neurodegenerative disorder of alpha motor neurons of spinal cord associated with progressive muscle weakness and... 相似文献
50.
Kwek Jia Liang Griva Konstadina Kaur Navreen Chong Kay Yuan Chua Zi Yang Sim Gim Hong Andy Ng Li Choo Yong Pay Wen Tung Yu-Tzu Lim Lydia Wei Wei Teo Su Hooi Choo Jason Chon Jun Foo Marjorie Wai Yin Jafar Tazeen Hasan 《International urology and nephrology》2022,54(4):917-926
International Urology and Nephrology - This study aimed at determining the feasibility of conducting a large-scale pragmatic effectiveness study on the implementation of multidisciplinary care... 相似文献