全文获取类型
收费全文 | 17934篇 |
免费 | 1362篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 149篇 |
儿科学 | 398篇 |
妇产科学 | 352篇 |
基础医学 | 2177篇 |
口腔科学 | 481篇 |
临床医学 | 1865篇 |
内科学 | 3450篇 |
皮肤病学 | 203篇 |
神经病学 | 1737篇 |
特种医学 | 691篇 |
外科学 | 2721篇 |
综合类 | 245篇 |
现状与发展 | 1篇 |
一般理论 | 30篇 |
预防医学 | 1697篇 |
眼科学 | 561篇 |
药学 | 1392篇 |
中国医学 | 26篇 |
肿瘤学 | 1197篇 |
出版年
2023年 | 154篇 |
2022年 | 303篇 |
2021年 | 653篇 |
2020年 | 327篇 |
2019年 | 480篇 |
2018年 | 575篇 |
2017年 | 412篇 |
2016年 | 438篇 |
2015年 | 533篇 |
2014年 | 725篇 |
2013年 | 872篇 |
2012年 | 1393篇 |
2011年 | 1354篇 |
2010年 | 734篇 |
2009年 | 693篇 |
2008年 | 1097篇 |
2007年 | 1103篇 |
2006年 | 1063篇 |
2005年 | 1086篇 |
2004年 | 951篇 |
2003年 | 847篇 |
2002年 | 767篇 |
2001年 | 181篇 |
2000年 | 132篇 |
1999年 | 158篇 |
1998年 | 165篇 |
1997年 | 123篇 |
1996年 | 115篇 |
1995年 | 93篇 |
1994年 | 80篇 |
1993年 | 75篇 |
1992年 | 106篇 |
1991年 | 95篇 |
1990年 | 86篇 |
1989年 | 98篇 |
1988年 | 88篇 |
1987年 | 84篇 |
1986年 | 69篇 |
1985年 | 68篇 |
1984年 | 68篇 |
1983年 | 69篇 |
1982年 | 54篇 |
1981年 | 56篇 |
1980年 | 49篇 |
1979年 | 44篇 |
1978年 | 52篇 |
1977年 | 37篇 |
1976年 | 48篇 |
1974年 | 52篇 |
1973年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Alex L. van Bemmel Rutger H. van den Hoofdakker Domien G. M. Beersma Antoinette L. Bouhuys 《Psychopharmacology》1993,113(2):225-230
Drug-induced improvement of depression may be mediated by changes in sleep physiology. The aim of this study was to relate changes in sleep polygraphic variables to clinical state during treatment with citalopram, a highly specific serotonin uptake inhibitor. Sixteen patients took part. The study was single-blind and uncontrolled. A 1-week wash-out period was followed by 1 week of placebo administration, a medication period of 5 weeks, and a 1-week placebo period. For the entire group a significant decrease of rapid eye movement sleep (REMS) and a significant lengthening of REMS latency were observed initially as well as at the end of treatment. No changes in sleep continuity were found, but non-REMS stage 2 (percentage) was significantly increased. On the basis of clinical change, as expressed by the scores of the Hamilton Rating Scale for Depression, at the end of the citalopram treatment the patient group was split in two halves: eight less and eight more improved patients. The groups did not differ with respect to any sleep polygraphic varible. 相似文献
42.
43.
Early Determinants of Adult Metabolic Regulation: Effects of Infant Nutrition on Adult Lipid and Lipoprotein Metabolism 总被引:4,自引:0,他引:4
44.
Perinchery Narayan M.D. George Fournier M.D R. Indudhara M.D. R. Leidich M.D. K. Shinohara M.D. Alex Ingerman M.D. 《Urology》1994,43(6)
Objective. This prospective study was undertaken to evaluate the safety and efficacy of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser for treatment of symptomatic benign prostatic hyperplasia (BPH).Methods. A total of 61 patients at a mean age of 71.6 years with symptomatic bladder outlet obstruction due to BPH underwent transurethral evaporation of prostate (TUEP) using Nd:YAG laser. Twelve of the patients were experiencing acute retention. Pre- and postoperative evaluation consisted of American Urological Association (AUA) symptom questionnaire and a sexual function questionnaire, uroflowmetry, postvoid residual urine, electrolytes, blood urea nitrogen, creatinine, hematocrit, and prostate volume estimation by transrectal ultrasound. TUEP was achieved by employing a side-firing Nd:YAG laser fiber with a durable quartz reflector and high-power density (Ultraline, Heraeus LaserSonics, Milpitas, CA) that was used in a contact mode.Results. All patients have been evaluated for three months, 26 for six rnonths, and 7 for twelve months. Mean prostatic size was 41.1 g. The mean improvement in symptom scores at one, three, six, and twelve months was 69.8 percent, 70.9 percent, 76.0 percent, and 70.9 percent, respectively (P = < 0.0001). The mean increase in maximum uroflow at one, three, six, and twelve months was 63.4 percent, 66.7 percent, 41.94 percent, and 164.52 percent, respectively (P = < 0.0001). There was no instance of significant fluid absorption or bleeding. The duration of postoperative catheterization was two days in 43 patients, three to seven days in 16 patients, and two to three weeks in 2 patients. There were no deaths. All patients evaluated by TRUS at six months had open channeling defects. Videocystoscopy performed in 16 patients at two to three months postoperatively revealed tissue slough. At repeat cystoscopy in these patients at six months, the prostatic fossa was completely healed with no evidence of tissue slough.Conclusions. It is concluded that the technique of TUEP using Nd:YAG laser is safe and, in preliminary results, appears apparently effective in the management of BPH. 相似文献
45.
Alex Y. Chang Z. Nora Tu Julia L. Smith Philip Bonomi Thomas J. Smith Peter H. Wiernik Ronald Blum 《Investigational new drugs》1995,13(2):137-141
Summary Fifty-five patients with metastatic non-small cell lung cancer (NSCLC) were entered into this phase II randomized study for evaluating three new agents: gallium nitrate, amonafide and teniposide. The patients had to have ECOG performance status 0 or 1, no prior chemotherapy, and adequate hematological, hepatic and renal functions. Forty-seven patients were eligible and evaluable. Fourteen were randomized to receive gallium nitrate, 18 to amonafide and 15 to teniposide. Seventy-four percent of eligible patients were male. The majority of patients (89%) had an ECOG performance status 1. ECOG grade 4 toxicity occurred twice in patients on gallium nitrate, seven times on amonafide and 18 times on teniposide. The cause of death was attributed to amonafide in one patient (from sepsis) and to teniposide in two patients (due to infection and leukopenia). There was no objective response in all the patients entered. The overall survival times ranged from 2 weeks to 156 weeks with a median of 23 weeks. There were no survival differences among the three treatment arms. We conclude that gallium nitrate, amonafide and teniposide are inactive in metastatic NSCLC and do not warrant any further testing in this disease.The contents of this study is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute. 相似文献
46.
47.
Alex Iranzo Esteban Mu?oz Joan Santamaria Isabel Vilaseca Montserrat Milà Eduardo Tolosa 《Movement disorders》2003,18(10):1179-1183
We evaluated the occurrence of REM sleep behaviour disorder (RBD) and vocal cord abductor paralysis (VCAP) in a group of 9 Machado-Joseph disease (MJD) patients. RBD was diagnosed by clinical history plus audiovisual polysomnography in 4 men and 1 woman (55%). While dreaming, 4 fell out of the bed and the other injured his arms. Laryngoscopy detected bilateral VCAP in 1 patient with stridor who required emergency tracheotomy, and partial vocal cord abductor restriction in 2. RBD and VCAP are two potentially injurious conditions that should be considered part of the clinical spectrum of MJD. 相似文献
48.
Marcia W. Swanson P.T. Forrest C. Bennett M.D. Kirkwood K. Shy M.D. Michael F. Whitfield M.D. 《Developmental medicine and child neurology》1992,34(4):321-337
The predictive validity of infant neuromotor evaluation by the Movement Assessment of Infants (MAI) was investigated in low-birthweight infants. Motor performance at four and eight months was examined in relation to neurodevelopmental outcome at 18 months of age. Correlations were equally strong between total MAI risk scores at four and eight months and performance on the Bayley Scales. Muscle tone observations were more discriminating at four months, and automatic reactions and volitional movement were most predictive at eight months. The MAI was highly sensitive to neurodevelopmental abnormality at four and eight months and more sensitive than the Bayley Motor Scale; both assessment tools had lower specificity at eight months. The high false-positive rate is attributed to transient neuromotor abnormalities and immaturity of motor function in low-birthweight infants with normal outcome. 相似文献
49.
Pallav J Shah Manoj Durairaj Ian Gordon John Fuller Alex Rosalion Siven Seevanayagam James Tatoulis Brian F Buxton 《European journal of cardio-thoracic surgery》2004,26(1):118-124
OBJECTIVE: The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. METHODS: 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. RESULTS: 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). CONCLUSIONS: Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied. 相似文献
50.