全文获取类型
收费全文 | 631篇 |
免费 | 34篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 39篇 |
妇产科学 | 13篇 |
基础医学 | 60篇 |
口腔科学 | 10篇 |
临床医学 | 77篇 |
内科学 | 76篇 |
皮肤病学 | 21篇 |
神经病学 | 70篇 |
特种医学 | 48篇 |
外科学 | 75篇 |
综合类 | 31篇 |
预防医学 | 44篇 |
眼科学 | 25篇 |
药学 | 28篇 |
肿瘤学 | 49篇 |
出版年
2023年 | 8篇 |
2022年 | 13篇 |
2021年 | 23篇 |
2020年 | 11篇 |
2019年 | 20篇 |
2018年 | 18篇 |
2017年 | 15篇 |
2016年 | 20篇 |
2015年 | 22篇 |
2014年 | 26篇 |
2013年 | 29篇 |
2012年 | 44篇 |
2011年 | 44篇 |
2010年 | 30篇 |
2009年 | 23篇 |
2008年 | 32篇 |
2007年 | 46篇 |
2006年 | 32篇 |
2005年 | 28篇 |
2004年 | 24篇 |
2003年 | 29篇 |
2002年 | 26篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1970年 | 3篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1947年 | 1篇 |
1892年 | 1篇 |
1891年 | 1篇 |
排序方式: 共有668条查询结果,搜索用时 15 毫秒
11.
PURPOSE: To evaluate the efficacy of preemptive analgesia in surgical repair of retinal detachment (RD) using scleral buckle and cryopexy under general anesthesia. METHODS: Thirty patients who were scheduled for rhegmatogenous RD surgical repair using scleral buckle and cryopexy and who were American Society of Anesthesiologists physical status I, II, or III were included in this study. The patients were randomly divided into two equal groups. The surgery was done under general anesthesia in both groups, but in Group 2, sub-Tenon anesthesia was given as preemptive analgesia after induction anesthesia and before start of surgery. Both groups were statistically comparable as regards patient age and weight and duration of anesthesia and surgery. RESULTS: The incidences of intraoperative oculocardiac reflex and postoperative vomiting were significantly lower in Group 2 compared with Group 1 (P < 0.001 and 0.0113, respectively). The time of first postoperative analgesic dose was significantly shorter in Group 1 (46.67 +/- 18.84 minutes) compared with Group 2 (162.67 +/- 29.391 minutes) (P < 0.001). The total analgesic consumption per 24 hours was significantly higher in Group 1 compared with Group 2 (P < 0.001). The time of discharge from the hospital was significantly shorter in Group 2 (8.8 +/- 2.704 hours) compared with Group 1 (12.4 +/- 3.481 hours) (P = 0.0018). CONCLUSION: The use of sub-Tenon block as preemptive analgesia after induction of general anesthesia and before the start of rhegmatogenous RD surgical repair was effective in reducing postoperative pain and analgesic requirements compared with an unblocked group. The use of sub-Tenon block was also effective in reducing intraoperative incidence of oculocardiac reflex and postoperative incidence of vomiting. 相似文献
12.
OBJECTIVE: To determine the location and radiological characteristics in children with abdominal hydatid disease (HD). MATERIALS AND METHODS: Thirty-one children (average age: 7.2 years) with abdominal HD were studied. The number, location, diameter and internal architecture of the cysts were assessed with abdominal ultrasonography (US) and computed tomography (CT). Density measurements and enhancement patterns were determined on CT. RESULTS: Twenty-one children had hepatic HD. The remaining 10 children had both hepatic and extrahepatic cysts. There were splenic cysts in five children, peritoneal cysts in two children and combined splenic and peritoneal cysts in three children. The most common site of the cysts was the liver (64%), followed by the spleen (20%) and the peritoneal cavity (16%). The seven intraabdominal cysts, which were not detected by US, were 20 mm or less in diameter. CONCLUSION: CT may demonstrate additional small intrahepatic or unsuspected extrahepatic cysts. Although rare, splenic or peritoneal hydatidosis should be included in the differential diagnosis of a cystic splenic or peritoneal lesion. Familiarity with atypical locations of HD may be helpful in making a prompt, accurate diagnosis. We think that in particular patients, especially those who had diagnostic problem and who are under surgical planning, CT should be performed additionally. 相似文献
13.
14.
Cervico-oculo-acoustic (COA) or Wildervanck syndrome is characterized by the triad of Klippel-Feil anomaly, bilateral abducens palsy with retracted bulbs (Duane 'syndrome') and hearing loss. The clinical findings of this syndrome have been well documented. A few case reports with MRI findings have appeared in the literature showing brainstem and cerebellar hypoplasia and vertebral segmentation anomalies. Our case is unique in that diastematomyelia of the lower medulla and cervical cord was accompanied by vermian hypoplasia, tonsillar herniation and resulting triventricular hydrocephalus in a child with Wildervanck syndrome. This case is presented with MR images. Children with Wildervanck syndrome should be investigated for craniospinal abnormalities with MR imaging. 相似文献
15.
Impact of pager notification on report verification times 总被引:2,自引:0,他引:2
RATIONALE AND OBJECTIVES: The purpose of this study was to assess the impact on times of verification (TOVs) by a pager notification system (PNS) that informs physicians when reports are available for signature. MATERIALS AND METHODS: An automated PNS was implemented in the authors' department in November 2000. Monthly report verification times of each physician were collected for 3 months in the years before and after initiation of the PNS. Radiologists enrolled in the PNS and those who were not were assigned into two groups for analysis. Mean TOVs for the two sets of 3 months and for the two groups were calculated and differences recorded. Two-tailed t tests were used to assess for statistical differences between the groups. RESULTS: Twenty-nine of 37 radiologists voluntarily enrolled in the PNS (group 1). Mean TOV was 26.75 hours (standard deviation [SD] = 17.76) for these physicians before and 14.48 hours (SD = 11.86) after the PNS was employed (P < .01). For those physicians who did not enroll in the PNS, mean TOV was 11.53 hours (SD = 5.55) before and 9.77 hours (SD = 9.86) after the PNS was employed (P = .33). Both the absolute and percentage reductions in TOVs were significantly greater for those physicians enrolled in the PNS than for those who were not (P = .035). Twenty-three of 29 (79%) physicians who used the PNS showed a reduction in their report turnaround times. CONCLUSION: Linking the PNS with the radiology information system to notify physicians of unsigned reports was effective in reducing report verification times. 相似文献
16.
Achilles tendinopathy: some aspects of basic science and clinical management 总被引:4,自引:0,他引:4 下载免费PDF全文
Achilles tendinopathy is prevalent and potentially incapacitating in athletes involved in running sports. It is a degenerative, not an inflammatory, condition. Most patients respond to conservative measures if the condition is recognised early. Surgery usually involves removal of adhesions and degenerated areas and decompression of the tendon by tenotomy or measures that influence the local circulation. 相似文献
17.
Kader KN Moore LR Saul JM Zborowski M Ziats NP Bellamkonda RV 《Microvascular research》2001,61(2):220-226
18.
Mikhelashvili-Browner N Yousem DM Wu C Kraut MA Vaughan CL Oguz KK Calhoun VD 《AJNR. American journal of neuroradiology》2003,24(3):488-494
BACKGROUND AND PURPOSE: As more individuals are enrolled in clinical functional MR imaging (fMRI) studies, an understanding of how sex may influence fMRI-measured brain activation is critical. METHODS: We used fixed- and random-effects models to study the influence of sex on fMRI patterns of brain activation during a simple visuomotor reaction time task in the group of 26 age-matched men and women. We evaluated the right visual, left visual, left primary motor, left supplementary motor, and left anterior cingulate areas. RESULTS: Volumes of activations did not significantly differ between the groups in any defined regions. Analysis of variance failed to show any significant correlations between sex and volumes of brain activation in any location studied. Mean percentage signal-intensity changes for all locations were similar between men and women. A two-way t test of brain activation in men and women, performed as a part of random-effects modeling, showed no significant difference at any site. CONCLUSION: Our results suggest that sex seems to have little influence on fMRI brain activation when we compared performance on the simple reaction-time task. The need to control for sex effects is not critical in the analysis of this task with fMRI. 相似文献
19.
Twenty ASA III and IV adult patients scheduled for elective coronary artery surgery were included in the study. Anesthesia was induced and maintained with either sevoflurane (sevoflurane group; n = 10) or propofol (propofol group; n = 10). All preoperative cardiac medications were continued until the morning of surgery. There were significant decreases in mean arterial blood pressure, cardiac index and ejection fraction after CPB in propofol group compared with sevoflurane. Further, the plasma creatine kinase myocardial isoenzyme concentrations were significantly higher in propofol group but did not approach the critical values needed for diagnosis of myocardial infarction. Conclusion: It is concluded that, sevoflurane appears to be associated with better hemodynamic stability before and after CPB than propofol. This could be attributed to cardioprotective effect of sevoflurane during ischemia and reperfusion. 相似文献
20.
Kader HA Berman WF Al-Seraihy AS Ware RE Ulshen MH Treem WR 《Journal of pediatric gastroenterology and nutrition》2002,35(5):629-635
BACKGROUND: Patients with inflammatory bowel disease (IBD) have an increased incidence of thromboembolic events. This risk may be caused by an increased frequency of thrombophilic mutations such as factor V Leiden G1691A (FVL), prothrombin G20210A (PT), or methylene tetrahydrofolate reductase C667T (MTHFR). Prevalence rates of heterozygous mutations in FVL, PT, and MTHFR are reported for whites (1.8%, 1.3%, 26.6%, respectively), blacks (0.8%, 0.3%, and 12.4%, respectively), and Hispanics (1.2%, 2.4%, and 41.5%, respectively). We sought to determine the prevalence of these thrombophilic mutations in a large cohort of children with IBD. METHODS: Children aged 21 years or younger with IBD were genotyped for FVL, PT, and MTHFR mutations by polymerase chain reaction amplification and restriction enzyme digestion. Prevalence rates were compared with established rates in the respective populations. RESULTS: Of 92 patients enrolled, 89 (62 with Crohn disease, 24 with ulcerative colitis, and 3 with indeterminate colitis) had genotype results available. The mean age was 13.3 +/- 4.2 years (range, 2-21 years). Statistical analysis was performed on 89 FVL, PT, and MTHFR allele pairs. Polymerase chain reaction genotyping identified 5 patients with heterozygous FVL mutations, 3 patients heterozygous for the PT mutation, and 36 patients heterozygous and 4 patients homozygous for the MTHFR mutation. The thrombophilic allele mutation frequencies in our sample were not significantly different from predicted weighted average values: FVL, 2.8% versus 1.5%; PT, 1.7% versus 1.1%; and MTHFR, 24.7% versus 24.4%. In 24 patients with a family history of thrombosis, 1 was heterozygous for FVL and for MTHFR, 1 was heterozygous for FVL and homozygous for MTHFR, 2 were heterozygous for PT, and 9 were heterozygous MTHFR. There was no significant correlation between family history of thrombosis and presence of a thrombophilic mutation. The four patients with homozygous mutations for MTHFR, two of whom also were heterozygous for FVL, did not have either a personal history of thrombosis or a family history of thrombotic events. Two patients had thrombotic events without mutations in these genotypes: one had protein S deficiency and the other had no identifiable cause. CONCLUSIONS: The presence of genetic mutations that predispose to hypercoagulable states does not appear to correlate with the prevalence of IBD or to thromboembolic events in patients with IBD. There was no statistical difference between the proportions of the mutated allele frequency in our study patients and the general population. 相似文献