全文获取类型
收费全文 | 1157篇 |
免费 | 69篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 51篇 |
妇产科学 | 12篇 |
基础医学 | 100篇 |
口腔科学 | 29篇 |
临床医学 | 96篇 |
内科学 | 249篇 |
皮肤病学 | 11篇 |
神经病学 | 45篇 |
特种医学 | 176篇 |
外科学 | 193篇 |
综合类 | 9篇 |
预防医学 | 75篇 |
眼科学 | 10篇 |
药学 | 54篇 |
中国医学 | 3篇 |
肿瘤学 | 137篇 |
出版年
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 9篇 |
2019年 | 30篇 |
2018年 | 33篇 |
2017年 | 22篇 |
2016年 | 20篇 |
2015年 | 33篇 |
2014年 | 21篇 |
2013年 | 48篇 |
2012年 | 41篇 |
2011年 | 39篇 |
2010年 | 49篇 |
2009年 | 54篇 |
2008年 | 37篇 |
2007年 | 43篇 |
2006年 | 34篇 |
2005年 | 37篇 |
2004年 | 36篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 11篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 38篇 |
1997年 | 36篇 |
1996年 | 30篇 |
1995年 | 28篇 |
1994年 | 34篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 22篇 |
1990年 | 20篇 |
1989年 | 25篇 |
1988年 | 29篇 |
1987年 | 20篇 |
1986年 | 28篇 |
1985年 | 20篇 |
1984年 | 20篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1976年 | 7篇 |
1975年 | 11篇 |
1974年 | 10篇 |
1972年 | 9篇 |
1969年 | 8篇 |
1968年 | 14篇 |
排序方式: 共有1251条查询结果,搜索用时 46 毫秒
1.
2.
3.
The interaction between piperoxan and alpha 2-agonists on sympathetic tone was studied in rats. The sympatho-inhibitory effect of alpha 2-agonists (clonidine, guanfacine, B-HT 933) was assessed by recording heart rate in normotensive bilaterally-vagotomized rats. Clonidine (3 micrograms/kg, i.c.v.) and B-HT 933 (100 micrograms/kg, i.c.v.) induced a bradycardia which was fully reversed by piperoxan (30 micrograms/kg, i.c.v.). However, in rats treated with guanfacine, piperoxan induced a partial recovery of the bradycardic effect. The injection of a small dose of the specific alpha 1-adrenoceptor blocking drug, AR-C 239 (10 micrograms/kg, i.c.v.) which, by itself did not modify heart rate, completely inhibited the reversal effect of piperoxan in rats treated with clonidine, B-HT 933 or guanfacine. In rat brainstem membranes, B-HT 933 was found to bind to both alpha 1- and alpha 2-adrenoceptors and was as potent as clonidine in competing for alpha 1-sites bound by [3H]prazosin. On the other hand, in bilaterally vagotomized rats, piperoxan (30 micrograms/kg, i.c.v.) induced an increase in blood pressure and heart rate which was inhibited by previous administration of AR-C 239 (10 micrograms/kg, i.c.v.). These data suggest that, by inhibiting central alpha 2-adrenoceptors, piperoxan unmasks central alpha 1-adrenoceptor stimulation by endogenous catecholamines leading to an increase in the sympathetic tone, but a full recovery in heart rate could be observed only with the mixed alpha 1- and alpha 2-adrenoceptor agonists, clonidine and B-HT 933. In addition, these data further indicate that alpha 1-adrenoceptors are implicated in a tonic control of the sympathetic nerve activity in normotensive rats. 相似文献
4.
B Moquet A Chantepie J P Fauchier P Cosnay R G Huguet J Laugier 《Archives fran?aises de pédiatrie》1989,46(1):11-17
For the past few years, a new method for the investigation and treatment of arrhythmias has been used: transoesophageal atrial pacing and recording (TAPR). In the light of 6 cases observed recently, we review the technical aspects and the indications for TAPR. A bipolar stimulation catheter is inserted in the oesophagus and positioned in the area where the atrial wave of greater amplitude is recorded. Atrial stimulation is done with impulses of long duration obtained with a special stimulator. Two cases validated this technique which was effective to correct atrial flutter in a neonate with heart failure resistant to medical treatment as well as in a 5 year-old child. The value of TAPR as a diagnostic tool in cases of tachycardia is discussed in the context of 2 cases: a 5 week-old with wide QRS and a 14 month-old with narrow QRS. Finally, the value of TAPR for monitoring the efficacy of anti-arrhythmia medications is illustrated by 4 cases of supraventricular tachycardia, in whom the optimal dosage of the anti-arrhythmic drug used was determined with the help of TAPR-induced tachycardia. The current literature concerning the technique, indications and results of TAPR are reviewed. This method is likely to take a great importance for the study and treatment of supraventricular arrhythmias in children. 相似文献
5.
B. Nordlinger B. Jeppsson W. El-Khoury L. Hannoun P. Frileux C. Huguet M. Malafosse R. Parc 《HPB surgery》1992,5(2):123-133
A retrospective review of 56 patients operated upon for tumours of Oddi was performed in order to
determine optimal diagnostic and therapeutic procedures.
Common presenting symptoms were jaundice (86%) and anemia (21%). Mean size of the tumour was
2.3 cm. Five tumours were benign and 51 were malignant. According to the classification of Martin, five
were grade I: 10 grade II; 18 grade III; and 18 grade IV. Forty-seven patients underwent resection of the
tumour: three local excisions for small benign tumors, six ampullectomies (followed in three by a
Whipples’ procedure for recurrence) and 41 Whipples’ procedures. The hospital mortality was 5.3%,
minor complications appeared in 21%.
The overall five years survival was 41%. It was 75% in grade I, 50% in grade II, 40% in grade III and
10% in grade IV. The patients who received ampullectomies were alive with a follow-up of one, two and
three years. All patients operated upon for a benign tumour were alive except one who died of cardiac
failure. Ultrasonography and duodenoscopy are the most useful tests for the diagnosis of tumours of
Oddi. Prognosis depends on the degree of infiltration of the duodenal wall and the presence of positive
lymph nodes. Whipples’ procedure is best but ampullectomy can be used in elderly or poor risk patients.
Malignant tumours of the ampullary region are infrequent and reported to constitute betwee 0.02 and
five percent of all cancers of the digestive tract. With wider application of endoscopic techniques, there
has been an increasing interest in this group of tumours during recent years. In the literature tumours of
Oddi are usually reported in the group of periampullary tumours, including tumours of the ampulla
itself, duodenal wall surrounding the ampulla, the distal part of the common bile duct and head of the
pancreas. We have wanted to distinguish specifically the tumours of the ampulla of Vater and have
adopted the term tumour of Oddi introduced by Marchal and Hureau.The sphincter of Oddi exactly
delineates the junction between the bile duct, pancreatic duct and duodenum. We wanted to avoid using
the anatomic term ampulla of Vater, since this structure rarely appears as an ampulla. This then
excludes tumours in the head of pancreas, common bile duct above ths phincter of Oddi and tumours of
the duodenal wall adjacent to the papilla. These tumours seem to behave differently from other
pancreatic tumours, as they carry a different prognosis and need special attention. We have therefore
reviewed retrospectively 56 patients with tumours of Oddi with special reference to diagnosis,
histopathologic examination and surgical therapy. 相似文献
6.
Epidermal growth factor excretion in burned rats 总被引:3,自引:0,他引:3
M. Farriol S. Schwartz J. Rossello R. Galard R. Catalan P. Huguet 《Burns : journal of the International Society for Burn Injuries》1994,20(6):496-498
Evidence for epidermal growth factor (EGF) involvement in the physiological response to burns was sought from urinary levels of EGF, urea and creatinine in male rats using a standardized thermal skin injury model (25 per cent body surface) and treated with fluid resuscitation. Postmortem, the skin lesions were studied by microscopy to guarantee the absence of inflammatory complications. Statistically significant differences were observed in body weight, urea and creatinine excretion when compared to the basal values. When EGF excretion results were evaluated as raw data (expressed as ng/mg of creatinine or ng/day) compared to basal levels, no statistically significant differences were observed. However, when the results were expressed as percentage increases with respect to the basal values, a statistically significant increase was found over the first 7 days postinjury (P = 0.029). 相似文献
7.
The properties of [3H]dihydropyridine (DHP), nitrendipine and (+)-PN 200-110, binding to rat cerebral membranes were investigated. In normotensive Wistar-Kyoto (WKY) adult rats, the highest densities of [3H]DHP binding sites were found in the hippocampus. Frontal cerebral cortex and hypothalamus had intermediate levels and no specific binding of [3H]DHP and [125I]iodipine could be detected in the brainstem membranes and more precisely in the nucleus tractus solitarius and in the locus coeruleus. Changes in the maximal number of DHP binding sites (Bmax) were observed in spontaneously hypertensive rats (SHR) and in old Sprague-Dawley rats. In adult SHR, there was a significant increase in theBmax values of [3H](+)-PN 200-110 binding in the hippocampus when compared to the values obtained in WKY. There was no difference in theBmax values between young (3 weeks) prehypertensive SHR and age-matched WKY. In senescent (26 months) Sprague-Dawley rats, theBmax values of [3H](+)-PN 200-110 binding were significantly reduced (30%) in the frontal cerebral cortex and the hippocampus, as compared with the number of DHP binding sites found in mature Sprague-Dawley rats (15 weeks). 相似文献
8.
9.
10.
Lymph node metastases: safety and effectiveness of MR imaging with ultrasmall superparamagnetic iron oxide particles--initial clinical experience 总被引:14,自引:0,他引:14