全文获取类型
收费全文 | 61042篇 |
免费 | 2860篇 |
国内免费 | 2131篇 |
专业分类
耳鼻咽喉 | 522篇 |
儿科学 | 1304篇 |
妇产科学 | 2063篇 |
基础医学 | 7113篇 |
口腔科学 | 1971篇 |
临床医学 | 5935篇 |
内科学 | 9279篇 |
皮肤病学 | 947篇 |
神经病学 | 3697篇 |
特种医学 | 3499篇 |
外国民族医学 | 10篇 |
外科学 | 6328篇 |
综合类 | 8059篇 |
一般理论 | 20篇 |
预防医学 | 5301篇 |
眼科学 | 1440篇 |
药学 | 4034篇 |
2篇 | |
中国医学 | 1258篇 |
肿瘤学 | 3251篇 |
出版年
2022年 | 305篇 |
2021年 | 539篇 |
2020年 | 427篇 |
2019年 | 480篇 |
2018年 | 573篇 |
2017年 | 501篇 |
2016年 | 638篇 |
2015年 | 686篇 |
2014年 | 847篇 |
2013年 | 1162篇 |
2012年 | 1868篇 |
2011年 | 3292篇 |
2010年 | 1879篇 |
2009年 | 1563篇 |
2008年 | 2167篇 |
2007年 | 2158篇 |
2006年 | 2227篇 |
2005年 | 2537篇 |
2004年 | 4336篇 |
2003年 | 4107篇 |
2002年 | 3619篇 |
2001年 | 2928篇 |
2000年 | 2320篇 |
1999年 | 2915篇 |
1998年 | 1951篇 |
1997年 | 1803篇 |
1996年 | 1234篇 |
1995年 | 988篇 |
1994年 | 938篇 |
1993年 | 1408篇 |
1992年 | 1382篇 |
1991年 | 1218篇 |
1990年 | 1076篇 |
1989年 | 982篇 |
1988年 | 842篇 |
1987年 | 726篇 |
1986年 | 712篇 |
1985年 | 530篇 |
1984年 | 381篇 |
1983年 | 335篇 |
1982年 | 224篇 |
1979年 | 336篇 |
1978年 | 270篇 |
1977年 | 249篇 |
1976年 | 225篇 |
1975年 | 230篇 |
1974年 | 254篇 |
1973年 | 253篇 |
1972年 | 258篇 |
1971年 | 227篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
81.
82.
83.
目的:研究特发性脊柱侧凸(IS)患者椎旁肌组织中神经营养素3(Neurotrophin-3,NT-3)在核酸水平(mRNA)的表达情况。方法:随机选择19例IS患者,年龄12~19岁,平均14.3岁,Cobb角42°~80°(平均54°)。手术中取顶椎(T7~T10)凸侧、凹侧椎旁肌肉组织,采用半定量RT-PCR法检测NT-3 mRNA表达水平。取4例相同年龄段的椎间盘突出患者手术切口头端非病变部位椎旁肌肉组织作为对照。结果:对照组椎旁肌中NT-3的mRNA表达阳性率50%,相对表达量为0.0237±0.0158,IS组患者椎旁肌中表达阳性率63.16%,相对表达量为0.1213±0.0939,较对照组表达量增加(P=0.051)。9例Cobb角>50°的IS患者表达阳性率为44.44%,相对表达量0.0431±0.0359,和对照组无明显差异;10例Cobb角≤50°的IS患者中表达阳性率为80%,相对表达量为0.1604±0.0895,与对照组和Cobb角>50°的IS患者比较有明显增加(P<0.01)。结论:正常椎旁肌组织中NT-3在核酸水平微量表达,特发性脊柱侧凸患者椎旁肌组织中NT-3 mRNA表达增加,尤其在小角度IS患者中增加明显,提示IS患者中存在神经营养因子表达异常。 相似文献
84.
Raja Kandaswamy J. Keith Melancon Ty Dunn Miguel Tan Vincent Casingal Abhinav Humar William D. Payne Rainer W. G. Gruessner David L. Dunn John S. Najarian David E. R. Sutherland Kristen J. Gillingham Arthur J. Matas 《American journal of transplantation》2005,5(6):1529-1536
We compared three maintenance immunosuppressive regimens in a rapid discontinuation of prednisone protocol. From March 1, 2001, through December 31, 2003, 239 first and second kidney transplant recipients (166 LD; 73 DD) were randomized. All recipients were treated with Thymoglobulin; all received steroids intraoperatively and for 5 days postoperatively. Randomization was to cyclosporine-mycophenolate mofetil (n = 85); high-level tacrolimus (TAC) (8-12 ng/mL)-low-level sirolimus (SRL) (3-7 ng/mL) (n = 72); or low-level TAC (3-7 ng/mL)-high-level SRL (8-12 ng/mL) (n = 82). We found no difference at 24 months between groups in patient, graft, death-censored graft, or acute rejection-free graft survival, or in kidney function. Wound complications were more common in SRL-treated recipients (p = 0.02); we found no other differences between groups in complication rates. Our data suggest that excellent patient and graft survival and low rejection rates can be obtained using a variety of maintenance protocols without prednisone. 相似文献
85.
Rainer Cammann Ariane Miehlke 《Journal of child psychology and psychiatry, and allied disciplines》1989,30(6):899-906
All non-task-related body movements during school hours were listed in 11 normally active and 12 hyperactive boys. The mean number of movements was 48 +/- 7 per 45 minutes in the normal actives and 79 +/- 16 per 45 minutes in the hyperactives. The rather monotonous increment and decrement of motor activity during the 4-hr registration period was noticed only in hyperactive boys. These results could be a consequence of a circadian rhythm, as there was independence of type of school hours and of teacher personality. The cyclical level of activity in hyperactive boys was sometimes in the range of the normal actives. 相似文献
86.
F T McDermott G Whelan D J St John G L Barnes R Elliott R Herrmann G T Schmidt R A Smallwood 《The Medical journal of Australia》1987,146(10):525, 528-525, 529
Information on the relative incidence of Crohn's disease and ulcerative colitis was obtained by a prospective investigation at six Melbourne teaching hospitals. One hundred and eleven patients who presented with chronic inflammatory bowel diseases between 1980-1981 were admitted to the study. Forty (36%) patients were diagnosed as having Crohn's disease and 63 (57%) patients as having ulcerative colitis. The type of chronic inflammatory bowel disease could not be determined in eight (7%) patients. These findings suggest that the relative frequency of Crohn's disease and ulcerative colitis in Melbourne hospitals is within the range that is reported for northern Europe and the United States. 相似文献
87.
Fifty-nine patients with chronic generalized tonic-clonic or partial seizures refractory to the maximally tolerated daily dosage of single-drug therapy with carbamazepine, phenytoin, phenobarbital, or primidone subsequently received single-drug therapy with another one of these primary anticonvulsant drugs. Alternative single-drug therapy resulted in complete seizure control or more than 75% seizure reduction for 18 patients (31%). Side effects disappeared in 16 patients (27%). Patients with a good therapeutic response often had epilepsy of recent onset. Alternative single-drug therapy is beneficial for chronic refractory epilepsy and should be considered before a second drug is permanently added. 相似文献
88.
89.
90.
Carmine Zoccali Renke Maas Sebastiano Cutrupi Patrizia Pizzini Piero Finocchiaro Francesco Cambareri Vincenzo Panuccio Carmela Martorano Friedrich Schulze Giuseppe Enia Giovanni Tripepi Rainer Boger 《Nephrology, dialysis, transplantation》2007,22(3):801-806
BACKGROUND AND METHODS: The endogenous inhibitor of nitric oxide synthase (NOs) asymmetrical dimethyl-arginine (ADMA) has been implicated as a possible modulator of inducible NOs during acute inflammation. We examined the evolution in the plasma concentration of ADMA measured at the clinical outset of acute inflammation and after its resolution in a series of 17 patients with acute bacterial infections. RESULTS: During the acute phase of inflammation/infection, patients displayed very high levels of C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin and nitrotyrosine. Simultaneous plasma ADMA concentration was similar to that in healthy subjects while symmetric dimethyl-arginine (SDMA) levels were substantially increased and directly related with creatinine. When infection resolved, ADMA rose from 0.62 +/- 0.23 to 0.80 +/- 0.18 micromol/l (+29%, P = 0.01) while SDMA remained unmodified. ADMA changes were independent on concomitant risk factor changes and inversely related with baseline systolic and diastolic pressure. Changes in the ADMA/SDMA ratio were compatible with the hypothesis that inflammatory cytokines activate ADMA degradation. CONCLUSIONS: Resolution of acute inflammation is characterized by an increase in the plasma concentration of ADMA. The results imply that ADMA suppression may actually serve to stimulate NO synthesis or that in this situation plasma ADMA levels may not reflect the inhibitory potential of this methylarginine at the cellular level. 相似文献