全文获取类型
收费全文 | 1061篇 |
免费 | 73篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 60篇 |
妇产科学 | 8篇 |
基础医学 | 82篇 |
口腔科学 | 31篇 |
临床医学 | 165篇 |
内科学 | 196篇 |
皮肤病学 | 12篇 |
神经病学 | 35篇 |
特种医学 | 243篇 |
外科学 | 168篇 |
综合类 | 21篇 |
预防医学 | 30篇 |
眼科学 | 7篇 |
药学 | 33篇 |
中国医学 | 5篇 |
肿瘤学 | 41篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 29篇 |
2017年 | 15篇 |
2016年 | 21篇 |
2015年 | 22篇 |
2014年 | 32篇 |
2013年 | 26篇 |
2012年 | 32篇 |
2011年 | 40篇 |
2010年 | 43篇 |
2009年 | 56篇 |
2008年 | 36篇 |
2007年 | 24篇 |
2006年 | 17篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 17篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 49篇 |
1997年 | 53篇 |
1996年 | 64篇 |
1995年 | 48篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 17篇 |
1989年 | 34篇 |
1988年 | 30篇 |
1987年 | 32篇 |
1986年 | 33篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 13篇 |
排序方式: 共有1141条查询结果,搜索用时 15 毫秒
81.
82.
Anxiety in patients undergoing MR imaging 总被引:6,自引:0,他引:6
To determine and quantify the major sources of anxiety for patients undergoing magnetic resonance (MR) imaging and to suggest means by which to eliminate or diminish their negative effects, the authors studied anxiety in 46 subjects. Of these, 20 randomly selected subjects who successfully completed the examination participated in exit interviews. Six subjects who terminated the examination before completion also completed exit interviews. Pre-imaging and postimaging questionnaires (state-trait anxiety inventory) were administered to measure anxiety in the 20 other subjects. Anxiety was associated with the constrictive dimensions of the magnet bore, examination duration, coil noise, and temperature within the bore. Preparation at the point of referral was consistently absent, incomplete, or misleading. Patients used identifiable strategies to cope with the examination: blinding, breathing relaxation techniques, visualization of pleasant images, and performance of mental exercises. 相似文献
83.
Di Chiro G; Girton ME; Frank JA; Dietz MJ; Gansow OA; Wright DC; Dwyer AJ 《Radiology》1986,160(1):221-222
Canine cerebrospinal fluid rhinorrhea, which occurs frequently in purebred beagles, was demonstrated in two dogs on magnetic resonance images after cisternal introduction of gadolinium-DTPA dimeglumine. 相似文献
84.
Chest radiographs were compared for three groups of children 8-9 years old: 23 survivors of bronchopulmonary dysplasia (BPD), 33 survivors of hyaline membrane disease without BPD, and 35 survivors of premature birth without neonatal respiratory problems. Only four children in the second group and three in the third had abnormal lungs. Linear shadows, apparently representing strands of fibrosis or deep pleural fissuring, were seen more frequently (15 of 23) in the BPD group than in the others (P less than .0001). Seventeen children in the BPD group had definite pulmonary abnormalities, none of them severe. The anteroposterior dimension of the chest in survivors of BPD tended to be decreased (P less than .001 vs that of reported control subjects). 相似文献
85.
Dr James H. Philip ME MD Daniel B. Raemer PhD 《Journal of clinical monitoring and computing》1986,2(3):151-154
A prototype electronic monitoring stethoscope was constructed from readily available, high-quality components. It consisted of a conventional precordial or esophageal probe connected to a microphone by a rubber adapter. The microphone was connected by lightweight wire to an amplifier and headphones. Twenty-one anesthesia clinicians evaluated the stethoscope and responded to a multiple-choice preference questionnaire. The electronic stethoscope was judged to perform better than the conventional stethoscope in most categories evaluated. The electronic device was perceived to be louder, clearer in sound reproduction, more efficacious for monitoring, and easier to use continuously, and its head-phones were considered more comfortable than the conventional carpiece. Based on our results, we conclude that amplified stethoscopes have the potential to improve monitoring. Further development of electronic stethoscope monitoring seems warranted and is continuing. 相似文献
86.
WILLIAMS PS; STEVENS ME; FASS G; IRONS L; BONE JM 《QJM : monthly journal of the Association of Physicians》1991,81(1):837-855
SUMMARY Ninety-five patients (63 male, 32 female), age 45±2 years(mean±SEM) with chronic renal failure of varied aetiologywere randomized to receive either a conventional low proteindiet (0.6 g/kg/day protein, 800 mg phosphate; n=33), a low phosphatediet (providing approximately 1000 mg phosphate plus an orallyadministered phosphate binder, minimum protein intake 0.8 g/kg/day;n=30) or to control (minimum protein intake 0.8 g/kg/day, nophosphate restriction; n=32). Patients were reviewed for a minimumof 6 months before randomization and were withdrawn from thestudy if plasma creatinine exceeded 900 µmol/1, plasmaphosphate was > 2.0 mmol/1 or at the onset of uraemic symptoms. Following randomization patients were studied for an averageof 19±3 months. Mean plasma creatinine rose from 398±33to 600±50 µmol/1. Dietary protein intake was estimatedat 0.69±0.02 g/kg/day in the low protein group, 1.02±0.05in the low phosphate and 1.14±0.05 in the controls, phosphateintake was 815±43, 1000± 47, and 1315±57mg/day, respectively. Urinary urea excretion and protein catabolicrates were significantly reduced (p<0.01) only in those onprotein restriction, at 213±9 mmol/24 hours and 0.71g/kg/day, respectively. Phosphate excretion was significantlylower (p<0.05) in both the low protein group (17.9±0.8mmol/24 hours) and the low phosphate group (18.6±1.0mmol/24 hours) compared to controls. Changes in body weight,muscle mass and serum transferrin, albumin and immunoglobulinswere comparable between the groups. Mean blood pressure followingrandomization was 150/89±3/1 (low protein), 148/87±3/1(low phosphate) and 146/87±3/1 (controls). Progression of renal failure was analysed by rate of fall ofcreatinine clearance (ml/min/ 1.73 m2/month), by rate of deteriorationderived from reciprocal plasma creatinine against time plots(1/mmol/year) and to assess individual patient's response totreatment by two phase linear regression (breakpoint)analysis of reciprocal plasma creatinine/time plots. Progressionwas analysed only in patients seen for at least 3 months followingrandomization. The rate of fall of creatinine clearance was not significantlydifferent between the groups (ANOVA): 0.56±0.08 ml/min/1.73m2/month (low protein, n=28), 0.44±0.07 (low phosphate,n=23) and 0.69±0.11 (control, n=27). In 50 patients (18low protein, 16 low phosphate and 16 control) whose rate ofprogression could be calculated before and after randomization,there was a fall in rate of progression averaging 0.18 ml/min/1.73m2/month in those on low protein diet and those on low phosphatediet, but a rise of 0.08 in the controls. These differenceswere, however, not statistically significant. Similar resultswere obtained when the rates of deterioration were calculatedfrom plasma creatinine. Significant individual improvements(p<0.01) in rates of progression by breakpointanalysis occurred in 17 patients: six on low protein, sevenon low phosphate and in four controls. Sixty-one (72 per cent)of the patients examined by this method showed no significantchange in the rate of progression while seven patients had acceleratedprogression. There was no difference in the requirement formaintenance dialysis facilities between groups. No significant benefit of protein and phosphate restrictionwas therefore demonstrated. 相似文献
87.
ME Lenaerts 《Cephalalgia : an international journal of headache》2008,28(S1):12-15
The ICHD-II criteria for post-traumatic headache (PTH) are strictly outlined. PTH can be subdivided into an acute and a chronic forms, the former likely nociceptive in nature, the latter likely neuropathic. The time of transition between the acute and the chronic forms is artificial and in the future should be better based on clear clinical or rather biological data. Chronic PTH often presents as one of the primary headache syndromes, e.g. migraine or tension-type headache. Its biology is poorly understood and whether it merely represents the expression of the primary headache or it has a distinct pathogenesis remains unclear. The frontal lobe is often affected in traumatic head injury. Its dysfunction can cause an array of clinical consequences that have an impact on the patient's symptomatology and therapeutic outcome. Its recognition is likely to improve patient management quality. 相似文献
88.
Time-dependent loss of surface complement regulatory activity during storage of donor blood 总被引:2,自引:0,他引:2
The survival of transfused red cells (RBCs) diminishes with time of in vitro storage in blood banks, but the molecular mechanisms underlying the slow but incessant deterioration are incompletely understood. To investigate the possibility that impaired resistance to autologous complement attack could play a role in this phenomenon, packed RBCs stored for variable periods were assayed for decay-accelerating factor (DAF) and CD59, two glycoinositol-phospholipid (GPI)-anchored, membrane- associated complement regulatory proteins that function physiologically to protect blood cells from autologous complement activation on their surfaces. Immunoradiometric and flow cytometric assays employing DAF and CD59 monoclonal antibodies showed that levels of both surface proteins gradually declined over 6 weeks. Digestion analyses with phosphatidylinositol-specific phospholipase C, an enzyme that releases GPI-anchored proteins from cell surfaces, showed that DAF and CD59 molecules with GPI anchors containing unacylated inositol were preferentially lost. These findings suggest: 1) that DAF and CD59 molecules with acylated GPI anchors are more stable in RBC membranes than are molecules with unacylated GPI anchors, and 2) that DAF and CD59 loss may participate with other membrane alterations that occur during in vitro storage in compromising the survival of transfused cells. 相似文献
89.
Sigurd?H.?BervenEmail author Steven?J.?Kamper Niccole?M.?Germscheid Benny?Dahl Christopher?I.?Shaffrey Lawrence?G.?Lenke Stephen?J.?Lewis Kenneth?M.?Cheung Ahmet?Alanay Manabu?Ito David?W.?Polly Yong?Qiu Marinus?de?Kleuver AOSpine Knowledge Forum Deformity 《European spine journal》2018,27(3):585-596
Purpose
Evaluation and surgical management for adult spinal deformity (ASD) patients varies between health care providers. The purpose of this study is to identify appropriateness of specific approaches and management strategies for the treatment of ASD.Methods
From January to July 2015, the AOSpine Knowledge Deformity Forum performed a modified Delphi survey where 53 experienced deformity surgeons from 24 countries, rated the appropriateness of management strategies for multiple ASD clinical scenarios. Four rounds were performed: three surveys and a face-to-face meeting. Consensus was achieved with ≥70% agreement.Results
Appropriate surgical goals are improvement of function, pain, and neural symptoms. Appropriate preoperative patient evaluation includes recording information on history and comorbidities, and radiographic workup, including long standing films and MRI for all patients. Preoperative pulmonary and cardiac testing and DEXA scan is appropriate for at-risk patients. Intraoperatively, appropriate surgical strategies include long fusions with deformity correction for patients with large deformity and sagittal imbalance, and pelvic fixation for multilevel fusions with large curves, sagittal imbalance, and osteoporosis. Decompression alone is inappropriate in patients with large curves, sagittal imbalance, and progressive deformity. It is inappropriate to fuse to L5 in patients with symptomatic disk degeneration at L5–S1.Conclusions
These results provide guidance for informed decision-making in the evaluation and management of ASD. Appropriate care for ASD, a very diverse spectrum of disease, must be responsive to patient preference and values, and considerations of the care provider, and the healthcare system. A monolithic approach to care should be avoided.90.
Michael G. Fehlings Branko Kopjar Ahmed Ibrahim Lindsay A. Tetreault Paul M. Arnold Helton Defino Shashank Sharad Kale S. Tim Yoon Giuseppe M. Barbagallo Ronald H.M. Bartels Qiang Zhou Alexander R. Vaccaro Mehmet Zileli Gamaliel Tan Yasutsugu Yukawa Darrel S. Brodke Christopher I. Shaffrey Osmar Santos de Moraes Mark B. Dekutoski 《The spine journal》2018,18(4):593-605