全文获取类型
收费全文 | 5367篇 |
免费 | 605篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 218篇 |
妇产科学 | 135篇 |
基础医学 | 111篇 |
口腔科学 | 96篇 |
临床医学 | 1229篇 |
内科学 | 1205篇 |
皮肤病学 | 113篇 |
神经病学 | 302篇 |
特种医学 | 184篇 |
外科学 | 1600篇 |
综合类 | 11篇 |
预防医学 | 306篇 |
眼科学 | 325篇 |
药学 | 35篇 |
肿瘤学 | 215篇 |
出版年
2023年 | 106篇 |
2021年 | 63篇 |
2020年 | 95篇 |
2019年 | 40篇 |
2018年 | 124篇 |
2017年 | 172篇 |
2016年 | 181篇 |
2015年 | 134篇 |
2014年 | 221篇 |
2013年 | 298篇 |
2012年 | 93篇 |
2011年 | 107篇 |
2010年 | 224篇 |
2009年 | 334篇 |
2008年 | 115篇 |
2007年 | 61篇 |
2006年 | 96篇 |
2005年 | 66篇 |
2003年 | 43篇 |
2002年 | 37篇 |
2001年 | 103篇 |
2000年 | 65篇 |
1999年 | 128篇 |
1998年 | 175篇 |
1997年 | 199篇 |
1996年 | 301篇 |
1995年 | 254篇 |
1994年 | 195篇 |
1993年 | 115篇 |
1992年 | 121篇 |
1991年 | 134篇 |
1990年 | 65篇 |
1989年 | 130篇 |
1988年 | 101篇 |
1987年 | 78篇 |
1986年 | 100篇 |
1985年 | 83篇 |
1984年 | 88篇 |
1983年 | 74篇 |
1982年 | 67篇 |
1981年 | 62篇 |
1980年 | 80篇 |
1979年 | 39篇 |
1978年 | 60篇 |
1977年 | 42篇 |
1976年 | 43篇 |
1975年 | 45篇 |
1972年 | 36篇 |
1964年 | 49篇 |
1963年 | 47篇 |
排序方式: 共有6140条查询结果,搜索用时 0 毫秒
91.
Bryan P. Conrad Diana L. Marchese Glenn R. Rechtine Mark Prasarn Gianluca Del Rossi MaryBeth H. Horodyski 《Journal of Athletic Training》2013,48(6):797-803
Context:
Two methods have been proposed to transfer an individual in the prone position to a spine board. Researchers do not know which method provides the best immobilization.Objective:
To determine if motion produced in the unstable cervical spine differs between 2 prone logrolling techniques and to evaluate the effect of equipment on the motion produced during prone logrolling.Design:
Crossover study.Setting:
Laboratory.Patients or Other Participants:
Tests were performed on 5 fresh cadavers (3 men, 2 women; age = 83 ± 8 years, mass = 61.2 ± 14.1 kg).Main Outcome Measure(s):
Three-dimensional motions were recorded during 2 prone logroll protocols (pull, push) in cadavers with an unstable cervical spine. Three equipment conditions were evaluated: football shoulder pads and helmet, rigid cervical collar, and no equipment. The mean range of motion was calculated for each test condition.Results:
The pull technique produced 16% more motion than the push technique in the lateral-bending angulation direction (F1,4 = 19.922, P = .01, η2 = 0.833). Whereas the collar-only condition and, to a lesser extent, the football-shoulder-pads-and-helmet condition demonstrated trends toward providing more stability than the no-equipment condition, we found no differences among equipment conditions. We noted an interaction between technique and equipment, with the pull maneuver performed without equipment producing more anteroposterior motion than the push maneuver in any of the equipment conditions.Conclusions:
We saw a slight difference in the motion measured during the 2 prone logrolling techniques tested, with less lateral-bending and anteroposterior motion produced with the logroll push than the pull technique. Therefore, we recommend adopting the push technique as the preferred spine-boarding maneuver when a patient is found in the prone position. Researchers should continue to seek improved methods for performing prone spine-board transfers to further decrease the motion produced in the unstable spine.Key Words: injuries, transfer techniques, logrollKey Points
- A slight difference in motion was measured between the 2 prone logrolling techniques, with the push technique producing less lateral-bending and anterior-posterior motion than the pull technique.
- The logroll push technique should be adopted as the preferred spine-boarding maneuver when a patient is found in the prone position.
- Individuals who may need to perform this rescue procedure should practice and become proficient in the logroll push technique.
- Researchers should continue to seek improved methods for transferring patients positioned prone to spine boards to further reduce the motion transmitted to the unstable spine.
92.
93.
Comparing schizophrenia symptoms in the Iban of Sarawak with other populations to elucidate clinical heterogeneity 下载免费PDF全文
94.
Acute and chronic effects of domperidone on gastric emptying in diabetic autonomic neuropathy 总被引:8,自引:0,他引:8
M. Horowitz MB BS P. E. Harding FRACP B. E. Chatterton FRACP P. J. Collins Bappsci Professor D. J. C. Shearman PhD 《Digestive diseases and sciences》1985,30(1):1-9
Gastric emptying was studied with a double radioisotopic method in 12 patients with insulin-dependent diabetes mellitus complicated by autonomic neuropathy and in 22 control subjects. In the diabetics, the acute and chronic effects of oral domperidone on gastric emptying, symptoms of gastroparesis, and glycemic control were assessed. Gastric emptying of solid and liquid was slower in diabetics than controls (P<0.001). Acute administration of domperidone increased the rate of both solid and liquid emptying (P<0.005). Domperidone was most effective in those patients with the greatest delay in gastric emptying. After chronic administration (35–51 days), domperidone had no significant effect on solid emptying (P>0.05), but was still effective in increasing liquid emptying (P<0.025). Symptoms of gastroparesis were less after domperidone (P<0.001).Dr. M. Horowitz was supported by a grant from the National Health and Medical Research Council of Australia. 相似文献
95.
Alloimmunization to platelets in heavily transfused patients with sickle cell disease 总被引:2,自引:0,他引:2
Bone marrow transplantation (BMT) is now an option for some patients with sickle cell disease (SCD). Many SCD patients are multiply transfused with red blood cells (RBCs), and may be immunized to alloantigens other than erythrocyte antigens. Because platelet refractoriness is a significant complication during BMT, we wished to determine the prevalence of alloimmunization to platelets in transfused SCD patients. Sera collected from 47 transfused and 14 untransfused SCD patients were screened for HLA and platelet-specific antibodies. Transfusion and RBC antibody histories were reviewed. A subset of the patients were rescreened 1 year later. Eighty-five percent of patients with at least 50 RBC transfusions (22 of 26), 48% of patients with less than 50 transfusions (10 of 21), and none of 14 untransfused patients demonstrated platelet alloimmunization (P < .05). Platelet alloimmunization was more prevalent than RBC alloimmunization (20% to 30%). Half of the platelet reactivity was chloroquine-elutable. Eighteen of 22 patients (82%) on chronic RBC transfusion remained platelet-alloimmunized 11 to 22 months after initial testing. In summary, 85% of heavily transfused SCD patients are alloimmunized to HLA and/or platelet-specific antigens. These patients may be refractory to platelet transfusion, a condition that would increase their risk during BMT. Leukodepletion in the transfusion support of SCD patients should be considered to prevent platelet alloimmunization. 相似文献
96.
97.
98.
Kent-Man Chu MB BS FRCS Ronnie Poon MB BS FRCS Henry H. Tuen MB BS Simon Y.K. Law MB BCh FRCS Frank J. Branicki DM FRCS FRACS John Wong PhD FRCS FACS 《Gastrointestinal endoscopy》1997,46(6):503-506
Background: A number of noncommercial preparations of urease test have been described. The present prospective study evaluated the accuracy of one such preparation for the diagnosis of Helicobacter pylori infection. Methods: From February 1996 to November 1996, all patients undergoing elective upper endoscopy in a single endoscopy facility were included. Three antral biopsy specimens were taken. Two specimens were subjected to histologic examination, and one specimen was placed into a “locally made rapid urease test” (LRUT). Results of histologic examinations were taken as standards for comparison. The final result of LRUT was obtained on scrutiny of color changes at 4 hours after the start of the test. Results: Two thousand three hundred sixteen patients (male/female = 1.5:1) with a mean age of 56.7 ± 0.4 years were included. Five hundred sixty-two patients (24.3%) had a history of eradication treatment for H. pylori. Nine hundred fifty-three patients (41.1%) were found to be positive for H. pylori on histologic examination. In patients in whom a history of eradication therapy was absent, the sensitivity, specificity, and positive and negative predictive values of the LRUT were 92.8%, 97.6%, 97.5%, and 93.0%, respectively. In patients with a history of eradication treatment, the corresponding figures were 76.1%, 99.6%, 96.2%, and 96.9%. Conclusions: The locally made rapid urease test provides a simple, safe, rapid, inexpensive, and accurate test for the diagnosis of H. pylori infection. (Gastrointest Endosc 1997;46:503-6.) 相似文献
99.
Ronald A. Hinder MB BCh FRCS FRCS Bernard K. P. Horn PhD Cedric G. Bremner MCh FRCS FRCS 《Digestive diseases and sciences》1976,21(11):940-945
Most methods of measurement of gastric emptying rely on the serial estimation of intragastric volume and do not separately account for the volume of fluid which has been added to the meal by gastric secretion, duodenal reflux, or swallowed saliva. The volume emptied is therefore underestimated. A method of measuring gastric emptying using [125I]RIHSA and the Volémetron is presented. The volume of fluid added to the meal is taken into consideration in this method, giving a more accurate reflection of gastric emptying. Using this method in the dog, emptying was found to be linear rather than exponential.Supported by South African Medical Research Council grant M14/71/51. 相似文献
100.
Wieslaw Bochenek MD John B. Rodgers Jr MD John A. Balint MB MRCP 《Digestive diseases and sciences》1971,16(10):865-872
The inhibitory effect of duodenal acidification and intraduodenal fat infusion on pentagastrin-stimulated gastric secretion in normal subjects and in patients with duodenal ulcer was studied. Intraduodenal infusion of acid resulted in inhibition of HCl secretion found to be significant only in ulcer patients. Pepsin output, although lower during the first 15 minutes of duodenal acidification, later increased. Intraduodenal infusion of olive oil resulted in significant inhibition of HCl and pepsin output in both groups of patients, which was maximal 45–60 minutes after the beginning of fat infusion. Gastric secretion was more readily inhibited in ulcer patients than in normal subjects; this difference was particularly evident in inhibition of pepsin secretion. In addition, decrease in concentration of HCl and pepsin was observed to be significant only in ulcer patients. Mechanisms by which duodenal acidification and fat inhibit gastric secretion are discussed. The results obtained suggest that secretin, which is probably responsible for inhibition after duodenal acidification, is not the inhibitor during inhibition by fat. The ulcer patients were found to have unimpaired mechanisms of inhibition by acid and fat. 相似文献