全文获取类型
收费全文 | 712篇 |
免费 | 66篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 25篇 |
妇产科学 | 5篇 |
基础医学 | 76篇 |
口腔科学 | 56篇 |
临床医学 | 84篇 |
内科学 | 139篇 |
皮肤病学 | 27篇 |
神经病学 | 8篇 |
特种医学 | 102篇 |
外科学 | 102篇 |
综合类 | 30篇 |
预防医学 | 53篇 |
眼科学 | 8篇 |
药学 | 38篇 |
中国医学 | 1篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 4篇 |
2020年 | 5篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 15篇 |
2015年 | 13篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 16篇 |
2011年 | 25篇 |
2010年 | 20篇 |
2009年 | 30篇 |
2008年 | 15篇 |
2007年 | 37篇 |
2006年 | 21篇 |
2005年 | 15篇 |
2004年 | 15篇 |
2003年 | 18篇 |
2002年 | 18篇 |
2001年 | 23篇 |
2000年 | 24篇 |
1999年 | 13篇 |
1998年 | 26篇 |
1997年 | 38篇 |
1996年 | 34篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 21篇 |
1992年 | 15篇 |
1991年 | 19篇 |
1990年 | 11篇 |
1989年 | 29篇 |
1988年 | 27篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 16篇 |
1982年 | 6篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 4篇 |
1969年 | 6篇 |
排序方式: 共有795条查询结果,搜索用时 500 毫秒
91.
Snyder DS; Negrin RS; O'Donnell MR; Chao NJ; Amylon MD; Long GD; Nademanee AP; Stein AS; Parker PM; Smith EP 《Blood》1994,84(5):1672-1679
Ninety-four consecutive patients with chronic myelogenous leukemia in first clinical chronic phase, median age of 34.0 years (range, 6.8 to 52.4 years), with a histocompatible sibling donor, were treated with fractionated total body irradiation (1,320 cGy) and high-dose etoposide (60 mg/kg) followed by allogeneic bone marrow transplantation (BMT). The median time from diagnosis to BMT was 7.0 months (range, 2.3 to 72.0 months). Sixty patients were treated before BMT with hydroxyurea alone, four patients with busulfan alone, one patient with interferon alone, and the other 29 patients were treated with various combinations of these drugs. Cumulative probabilities of overall survival, event- free survival, and relapse at 5 years were 73%, 64%, and 14%, respectively. The median follow-up time for surviving patients was 38 months, ranging from 12 to 88 months. By stepwise Cox regression analysis, significant prognostic variables were age at transplant, acute graft-versus-host disease > or = grade II, cytomegalovirus- associated interstitial pneumonitis, and years from diagnosis to BMT. 相似文献
92.
The influence of intracerebroventricular (ICV) vs intravenous (IV) administration of (D-Ala2, Met5) enkephalinamide (Dalamide) on normal and stimulated (cholera toxin) jejunal fluxes of water, Na+, and K+ were investigated in dogs prepared with a Thiry-Vella (TV) loop. Intestinal transport in the TV loop and concomitant transit time were measured during an infusion (2 ml/min) of an isotonic electrolyte solution alone, or containing 0.4 micrograms/ml of cholera toxin (CT). Basal net water absorption was slightly, but significantly (P less than 0.05), increased during an ICV infusion of Dalamide at 0.5 ng/kg/min, while the secretory effects of cholera toxin were markedly reduced by nearly 75%. Similar effects were observed for Na+ and K+ movement. In contrast, Dalamide infused intravenously at a five times higher dose, ie, 2.5 ng/kg/min did not affect the control and CT-stimulated water and electrolyte movements. The jejunal loop transit times were halved during CT infusion. Similar values were observed under Dalamide ICV administration as well as during a five times higher dose of Dalamide administered intravenously. It was concluded that (1) Dalamide administered into the CNS, but not peripherally, increased the absorption of water, Na+, and K+, causing a net reduction in their secretion induced by cholera toxin; and (2) these effects did not result from changes in transit time. These results also suggest that Met-enkephalin can act in the brain to affect the intestinal transport of water and electrolytes in dogs. 相似文献
93.
Roberts JL; Fishman EK; Hartman DS; Sanders R; Goodman Z; Siegelman SS 《Radiology》1986,158(3):613-617
Seven cases of lipomatous masses within the liver parenchyma were demonstrated with computed tomography (CT). Five of these cases were obtained from a retrospective review of 50 cases of renal angiomyolipoma in which the liver was adequately demonstrated. The other two cases were from the files of the Armed Forces Institute of Pathology and had no associated renal lesions. Three of the five cases were associated with tuberous sclerosis. In all seven cases, the fatty tumors appeared on CT scans as a well-defined, 0.8-13-cm mass, with attenuation coefficients of less than -30 HU. On ultrasound studies, the lesions were well circumscribed, highly echogenic, and similar to hemangiomas. While distinctly rare lesions, these lipomatous masses are not as unusual as the literature would indicate. One may anticipate such masses in patients with renal angiomyolipomas and in a relatively high percentage of those with tuberous sclerosis. 相似文献
94.
Groin pain associated with ultrasound finding of inguinal canal posterior wall deficiency in Australian Rules footballers 总被引:3,自引:0,他引:3
J. W. Orchard J. W. Read J. Neophyton D. Garlick 《British journal of sports medicine》1998,32(2):134-139
OBJECTIVES: To investigate the prevalence of inguinal canal posterior wall deficiency (sports hernia) in professional Australian Rules footballers using an ultrasound technique and correlate the results with the clinical symptom of groin pain. METHODS: Thirty five professional Australian footballers with and without groin pain were investigated blind with a dynamic high resolution ultrasound technique for presence of posterior wall deficiency. RESULTS: Fourteen players had a history of significant recent groin pain and ten of these were found to have bilateral inguinal canal posterior wall deficiency (p < 0.01). The relative risk for a history of groin pain with bilateral deficiency was 8.0 (95% confidence interval 1.73 to 37.1). Groin pain was also found to be associated with increasing age (p < 0.01) which was an independent risk factor. Surgical, clinical, and ultrasound follow up for players who underwent hernia repair confirmed the validity of ultrasound as a diagnostic tool. CONCLUSIONS: Dynamic ultrasound examination is able to detect inguinal canal posterior wall deficiency in young males with no clinical signs of hernia. This condition is very prevalent in professional Australian Rules footballers, including some who are asymptomatic. There was a correlation between bilateral deficiency and groin pain, although the temporal relationship between the clinical and ultrasound findings is not established by the current study. Ultrasound shows promise as a diagnostic tool in athletes with chronic groin pain who are considered possible candidates for hernia repair.
相似文献
相似文献
95.
Integration of local inputs in visual cortex 总被引:1,自引:0,他引:1
In mammalian visual cortex, local connections are ubiquitous, extensively
linking adjacent neurons of all types. In this study, optical maps of
intrinsic signals and responses from single neurons were obtained from the
same region of cat visual cortex while the effectiveness of the local
cortical circuitry was altered by focally disinhibiting neurons within a
column of known orientation preference. Maps of intrinsic signals indicated
that local connections provide strong and functional subthreshold inputs to
neighboring columns of other orientation preferences, altering the observed
orientation preference to that of the disinhibited column. However,
measuring the suprathreshold response using single-cell recordings revealed
only mild changes of preferred orientation over the affected region.
Because strongly tuned subthreshold inputs from cortex only marginally
affect the tuning of a cortical cell's output, it is concluded that local
cortical inputs are integrated weakly compared to geniculate inputs. Such
circuitry potentially allows for the normalization of responses across a
wide range of input activity through local averaging.
相似文献
96.
1. Eight women maintained on a constant diet throughout a single menstrual cycle were studied for cyclical changes in body-weight, carbohydrate, fat and protein metabolism. 2. A cyclical variation in weight occurred with two phases corresponding to the time of ovulation and menstruation. 3. Creatinine and nitrogen excretion in the urine also tended to be higher in the luteal phase. 4. Analysis of gas exchange in a respiratory chamber for 24 h periods at intervals during the cycle suggested that carbohydrate utilization tended to be less in the early follicular phase. 5. Feeding with a mixed diet produced marked increases in carbohydrate utilization during the day with little change in fat utilization from the fasting state. Carbohydrate utilization was less when fasting at night and tended to be less when fed during the day in the early follicular phase of the menstrual cycle. 6. Weight changes were not readily ascribed to changes in colonic function, or in glycogen or body protein storage. 相似文献
97.
The high incidence of injury in Rugby Union is well documented, particularly at elite levels of competition. This article describes the incidence and nature of all injuries sustained by elite Western Australian junior Rugby Union players during the 26 weeks up to and including the 1997 National Championship campaign. Informed consent was gained for each participant (n = 44) prior to completion of an extensive baseline questionnaire. Exposure and injury data were collected at each training session and game. The injury incidence rate over the 26 week period was 13.26/1000 player hours. Injury data were analysed by phase of play, position, severity and if occurred at games or training. The incidence of injury was significantly associated with the position played (chi2 = 67.49, p value = 0.008) and the phase of play in which the injury occurred (chi2 = 8.07, p value = 0.042). Tackling was the most dangerous phase of play (52% of injuries) and the most common site of injury was the lower limb (37%). Most injuries occurred during games (56%) and the flanker was the position most at risk of injury (12%). Further research is needed to identify the aetiology of injury at all levels of competition and to use these findings to develop effective injury prevention strategies in this sport. Position-specific risk factors should also be investigated, as should the mechanism of injury associated with tackling which is the phase of play in which significantly more injuries occur in rugby. 相似文献
98.
Prevention of transfusion-associated graft-versus-host disease: selection of an adequate dose of gamma radiation 总被引:1,自引:0,他引:1
To determine the optimal dose of gamma radiation necessary to inhibit T- lymphocyte function and prevent transfusion-acquired graft-versus-host disease (TA-GVHD), a donor plateletpheresis component was initially divided into ten 20-mL samples. One sample was not irradiated, while the other nine samples were treated with gamma radiation at doses ranging from 500 to 4500 cGy. T-lymphocyte function was subsequently measured by mixed lymphocyte cultures and mitogen stimulation assays. The results were assessed in each test by calculating the percentage of inhibition of each irradiated sample as compared to that of the unirradiated sample. The accuracy of the delivered dose of gamma radiation was measured with thermoluminescent dosimeters. It was concluded that a nominal dose of 3000 cGy (actual dose delivered, 2898 cGy) is the appropriate amount of gamma radiation needed to eliminate T- lymphocyte-mediated graft-versus-host disease. 相似文献
99.
Human papillomavirus infection of the oral mucosa. 总被引:3,自引:0,他引:3
This article reviews the lesions of oral mucosa that contain human papillomavirus (HPV). These HPV-associated lesions can be classified into two broad types on the basis of their biologic behavior, benign lesions and premalignant malignant or malignant lesions. Benign oral lesions include squamous cell papilloma (SCP), verruca vulgaris (VV), condyloma acuminatum (CA), and focal epithelial hyperplasia (FEH). Of these entities, VV, CA, and FEH demonstrate characteristic HPV-induced cytopathic effects, whereas SCP infrequently shows such changes. All of these lesions show a clear association with HPV. Premalignant and malignant oral lesions include leukoplakia and squamous cell carcinoma. The etiologic role of HPV in these lesions is still unclear. Koilocytosis is the most common cytopathic effect seen in both groups of lesions. Even though it is sometimes difficult to distinguish between hyperplastic lesions such as SCP, VV, and CA, clinical and certain histologic features can facilitate the diagnosis. Although exceptions do exist, each of the two classes of lesions is most commonly associated with particular HPV types. The benign oral lesions are associated with HPV 2, 4, 6, 11, 13, and 32; the malignant oral lesions are associated with HPV 16 and 18. No preferential association has been demonstrated between specific HPV types and a particular oral lesion. 相似文献
100.