全文获取类型
收费全文 | 247749篇 |
免费 | 12213篇 |
国内免费 | 465篇 |
专业分类
耳鼻咽喉 | 3199篇 |
儿科学 | 7683篇 |
妇产科学 | 5094篇 |
基础医学 | 36132篇 |
口腔科学 | 5807篇 |
临床医学 | 19461篇 |
内科学 | 54485篇 |
皮肤病学 | 6554篇 |
神经病学 | 22145篇 |
特种医学 | 7652篇 |
外国民族医学 | 101篇 |
外科学 | 30844篇 |
综合类 | 1052篇 |
一般理论 | 67篇 |
预防医学 | 22543篇 |
眼科学 | 4792篇 |
药学 | 17441篇 |
中国医学 | 735篇 |
肿瘤学 | 14640篇 |
出版年
2023年 | 1301篇 |
2022年 | 982篇 |
2021年 | 3725篇 |
2020年 | 2239篇 |
2019年 | 4148篇 |
2018年 | 7820篇 |
2017年 | 5159篇 |
2016年 | 5172篇 |
2015年 | 5821篇 |
2014年 | 6106篇 |
2013年 | 9773篇 |
2012年 | 16730篇 |
2011年 | 16797篇 |
2010年 | 8419篇 |
2009年 | 6397篇 |
2008年 | 14331篇 |
2007年 | 15284篇 |
2006年 | 14118篇 |
2005年 | 14013篇 |
2004年 | 13109篇 |
2003年 | 11939篇 |
2002年 | 11284篇 |
2001年 | 6507篇 |
2000年 | 6590篇 |
1999年 | 5825篇 |
1998年 | 1034篇 |
1997年 | 819篇 |
1996年 | 773篇 |
1992年 | 3340篇 |
1991年 | 3014篇 |
1990年 | 2886篇 |
1989年 | 2671篇 |
1988年 | 2530篇 |
1987年 | 2344篇 |
1986年 | 2253篇 |
1985年 | 2027篇 |
1984年 | 1507篇 |
1983年 | 1270篇 |
1982年 | 719篇 |
1979年 | 1292篇 |
1978年 | 920篇 |
1977年 | 864篇 |
1975年 | 852篇 |
1974年 | 1052篇 |
1973年 | 1065篇 |
1972年 | 998篇 |
1971年 | 981篇 |
1970年 | 911篇 |
1969年 | 967篇 |
1968年 | 833篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
131.
Stability of transverse expansion in the mandibular arch. 总被引:1,自引:0,他引:1
Jeffrey A Housley Ram S Nanda G Fr?ns Currier Dale E McCune 《American journal of orthodontics and dentofacial orthopedics》2003,124(3):288-293
This was a retrospective, longitudinal cephalometric and cast study of 29 white patients at pretreatment, posttreatment, and an average of 6 years 3 months postretention. The goal was to assess changes with treatment and retention with the expanding mandibular lingual arch appliance in conjunction with fixed edgewise treatment. Seven mandibular cast measurements were assessed, including arch crowding, arch perimeter, arch length, and arch width at the permanent canines, first premolars, second premolars, and first molars. Cephalometric radiographs were digitized, and 16 cephalometric measurements were made. Repeated-measures analysis of variance and 2-sample t tests were used to determine statistically significant changes. It was found that the expanding lingual arch used for less than 6 months with the mandibular fixed edgewise appliance caused an increase in both the transverse and sagittal dimensions of the mandibular dental arch. Transverse expansion was more stable in the posterior region of the mandibular dental arch than in the anterior region. Mandibular intercanine width increase could be maintained only by fixed retention. Although the maxillary and mandibular incisors were advanced and proclined, lip protrusion did not occur. 相似文献
132.
133.
Nephronophthisis related to homozygous NPHP1 gene deletion as a cause of chronic renal failure in adults. 总被引:1,自引:0,他引:1
134.
Luis Gajate Ascensión Martín Elena Elías Maria T Tenorio Angélica de Pablo Cristina Carrasco Adolfo Martínez Angel Candela Javier Zamora Fernando Lia?o 《Liver transplantation》2006,12(9):1371-1380
Although renal dysfunction is common after liver transplantation, postoperative renal function after split liver transplantation (SLT) has not been well studied. Renal function immediately after surgery was analyzed retrospectively in 16 patients that received a SLT (SLT group). The results were compared with corresponding data from 31 matched patients that received a full-size liver transplant (FSLT group) during the same period. Serum creatinine (SCr) was measured before surgery, and, after transplantation, daily during the first week and at days 14, 21, and 28. Renal dysfunction (RD) was defined as the requirement for renal replacement therapy (RRT) or a 100% increase in SCr if the basal value had been <1.0 mg/dL or a 50% increase in SCr if the basal value had been >1.0 mg/dL. SCr had to be at least 1.5 mg/dL for a diagnosis of RD to be considered. The classification of RD was: mild, SCr 1.5-2.4 mg/dL; moderate, SCr 2.5-4.0 mg/dL; or severe, SCr >4.0 mg/dL (the requirement for RRT). Both donor and recipient age and cold ischemia time were lower in the SLT group than in the FSLT group (P < 0.05). Length of surgery was longer in the SLT group (P < 0.05). There were no significant differences between groups with respect to Model for End-Stage Liver Disease scores, the need for transfusions, the length of admission to the intensive care unit (ICU), survival rate, individual severity index, or sepsis-related organ failure assessment scores at the time of diagnosing RD. Immunosuppression regimens were similar in both groups. RD developed in 82% of SLT patients, but in only 58% of FSLT patients (P = not significant [NS]). Among SLT patients, RD (23.0% mild, 15.5% moderate, and 61.5% severe) was more severe (P = 0.007) than in FSLT patients (63.1% mild, 15.8% moderate, and 24.1% severe). The requirement for RRT in the SLT group (43.7%) was significantly greater (P < 0.05) than that in the FSLT group (12.9%). This finding may be due to the different incidence of sepsis in the 2 groups (SLT 37.5% vs. FSLT 9.7%; P < 0.05). In conclusion, although the number of patients studied was small, our data suggest a higher incidence of RD and a greater requirement for RRT in patients that receive a split liver graft than in those that receive a full size liver graft. 相似文献
135.
Jean-Sébastien Fallu Jürgen Rehm Emmanuel N. Kuntsche Esther Grichting Neerav Monga Edward M. Adlaf Susan J Bondy Gerhard Gmel 《Sozial- und Pr?ventivmedizin》2006,8(1):363-372
Volume and profile of alcohol consumption among students and classmates as predictors of aggression and victimization: a multilevel
analysis among Swiss adolescents
Objective:
To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels. 相似文献136.
Jér?me Dumortier Marie-Claude Gagnieu Janine Salandre Olivier Guillaud Philipe Guillem Mustapha Adham Olivier Boillot 《Liver transplantation》2006,12(9):1342-1346
Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option. 相似文献
137.
L González-Bayón S González-Moreno G Ortega-Pérez 《European journal of surgical oncology》2006,32(6):619-624
The new treatment strategy for Peritoneal Surface Malignancy combines a cytoreductive surgery and perioperative intraperitoneal chemotherapy. Cytoreduction removes all macroscopic tumor. Intraperitoneal chemotherapy avoids implantation of microscopic residual tumor cells on intra-abdominal surfaces when it is administered intraoperatively and/or early in the postoperative period. Delivering cytotoxic drugs directly into the peritoneal cavity maximizes dose intensity and minimizes systemic toxicity. Hyperthermia is selectively cytotoxic for malignant cells and potentiates the effect of chemotherapy. Implementation of this procedure makes the perioperative personnel to face a risk of exposure to cytotoxic agents. Furthermore, peritonectomies and electro-evaporation of tumor nodules are performed with high voltage electrocautery, generating a large amount of surgical smoke during several hours. Inhalation of these fumes may be also a risk for healthcare workers. In this article, we analyse in depth these new risks of the operating room personnel, we review the literature, and we give guidelines for secure performance of cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy, as well as for early postoperative intraperitoneal chemotherapy administration. These new procedures are safe techniques for patients and healthcare workers provided adequate policies are adopted to avoid occupational exposure. 相似文献
138.
Rènée du Toit Katherine Soong Garry Brian Jacqueline Ramke 《Optometry and vision science》2006,83(8):582-588
PURPOSE: The advantages of a focometer (FOCOMETER) over other methods of refraction for use in developing countries are that it is lightweight, compact, relatively inexpensive, fairly quick, and easy to use with minimal training. This clinical trial compared the repeatability, validity, and ease of use of the focometer with an autorefractor. METHODS: The refractive status of the right eye of 80 participants was determined with an autorefractor (Canon RK3). Three measurements were also taken with the focometer. RESULTS: The spherical equivalent (M) of the focometer was 0.25 D more positive than the autorefractor (p < 0.001) and 84% of measurements were within 0.75 D of the autorefractor. The autorefractor detected astigmatism in 91% (73) of the eyes, whereas the focometer identified only 32% (26). The design of the clock target restricts cylinder axis accuracy to the nearest 15 degrees . There was evidence of a learning effect for the focometer: the second and third measurements were more repeatable in the untrained group. There were no differences between the mean (1.03 +/- 2.28) and third focometer (-1.05 +/- 2.32) measurements (p = 0.34). However, using the third focometer measurement, 94% of participants had visual acuities of at least 6/12(-2). CONCLUSIONS: This study highlighted the focometer's restricted power range, inaccuracy of astigmatism and axis determination, and dependence on subject understanding and compliance. Therefore, in most clinical settings, the focometer would not be adequate for quantifying refractive error, but the focometer spherical equivalent was within acceptable limits of the autorefractor, and the visual acuity with lenses determined by the focometer indicates its potential usefulness in public health settings, especially where only spherical ready-made spectacles are dispensed. There may be more cost-effective ways to determine refractive error in these circumstances. A potentially important enhancement in focometer methodology that improves its ease of use was identified: use only the third measurement for each eye. 相似文献
139.
o. goetze a. b. nikodem j. wiezcorek † m. banasch h. przuntek † t. mueller † w. e. schmidt & d. woitalla † 《Neurogastroenterology and motility》2006,18(5):369-375
Predictors of gastric emptying (GE) in patients with idiopathic Parkinson's disease (PD) of a solid and liquid meal are not well defined. For measurement of GE 80 patients with PD were randomly assigned to receive either a solid meal (250 kcal) containing 13C-octanoate (n = 40) or a liquid meal (315 kcal) with 13C-acetate (n = 40). All patient groups were off medication affecting motility and were matched for age, gender, body mass index, disease duration and severity, using Unified Parkinson's Disease Rating Scale (UPDRS). Gastric emptying was compared with a healthy control group (n = 40). Multiple regression analysis was used to determine predictors of gastric emptying. Exactly 88% and 38% of PD patients had delayed GE of solids and liquids respectively. Solid and liquid emptying was similar in women and men. There were no differences in GE in PD patients < 65 years of age when compared with patients > or = 65 years. Multiple regression analysis showed that motor handicaps such as rigour and action tremor are independent predictors of solid GE (r = 0.68, P < 0.001). The severity of motor impairment, but not any other neurological symptom, as assessed by UPDRS is associated with gastroparesis in PD and solid emptying is more likely to be delayed. 相似文献
140.
Social phobia, fear of negative evaluation and harm avoidance. 总被引:1,自引:0,他引:1
M Faytout J Tignol J Swendsen D Grabot B Aouizerate J P Lépine 《European psychiatry》2007,22(2):75-79
This naturalistic, prospective investigation examined the role of fear of negative evaluation and the personality trait of harm avoidance in the anxiety levels of treated social phobia patients. One hundred and fifty-seven patients with DSM-IV social phobia were assessed before starting treatment and were then followed for up to two years. As expected, greater fear of negative evaluation and higher scores of harm avoidance were associated with greater anxiety at the 6 month follow-up, and harm avoidance remained a significant predictor at 24 months. However, no evidence was found for an interaction between the personality and cognitive variables examined. The findings are discussed in terms of the relative independence of these factors, as well as their potential implications for the treatment of this disorder. 相似文献