全文获取类型
收费全文 | 911篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 8篇 |
妇产科学 | 8篇 |
基础医学 | 74篇 |
口腔科学 | 25篇 |
临床医学 | 67篇 |
内科学 | 298篇 |
皮肤病学 | 3篇 |
神经病学 | 133篇 |
特种医学 | 21篇 |
外科学 | 110篇 |
一般理论 | 2篇 |
预防医学 | 51篇 |
眼科学 | 10篇 |
药学 | 51篇 |
中国医学 | 1篇 |
肿瘤学 | 59篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 25篇 |
2013年 | 40篇 |
2012年 | 58篇 |
2011年 | 53篇 |
2010年 | 37篇 |
2009年 | 33篇 |
2008年 | 67篇 |
2007年 | 67篇 |
2006年 | 65篇 |
2005年 | 62篇 |
2004年 | 50篇 |
2003年 | 44篇 |
2002年 | 63篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1960年 | 2篇 |
1941年 | 2篇 |
排序方式: 共有936条查询结果,搜索用时 0 毫秒
1.
2.
Aldo Cunha Medeiros Irami Araújo Filho Vítor Brasil Medeiros Laíza Araújo Mohana Pinheiro Flávio Henrique Miranda Araújo Freire Italo Medeiros Azevedo José Brand?o-Neto 《Journal of investigative surgery》2007,20(1):41-48
After total gastrectomy, the ileocecal graft may act as a reservoir and protect against reflux but give rise to transposition of the ileum and cause possible changes in bile acid metabolism and nutrition. This study compared the ileocecal graft and jejunal pouch. Male Wistar rats weighing 265 +/- 22 g were submitted to sham operation (S), ileocecal interposition graft (IIG), and jejunal pouch interposition graft (JP) after total gastrectomy. Eight weeks later, the esophagus was examined for evidence of esophagitis. Nutritional biochemistry and weight profile were documented preoperatively and 8 weeks after surgery. The oral glucose tolerance test was performed. Thirty-three rats were operated on and 30 survived for 8 weeks. Esophagitis occurred in seven JP rats. Body weight was significantly higher in IIG than in JP rats (p < .05). Normal glucose tolerance to intragastric glucose load was observed in sham and operated rats. JP rats had a significant decrease in serum albumin, glucose, transferrin, hemoglobin, iron, folate, and calcium, compared to sham (p < .05). Cobalamine was significantly lower in IIG rats than in JP rats (p < .05). In the IIG and JP groups, serum/hepatic total bile acid did not differ significantly from preoperative and sham values. In conclusion, the IIG interposition graft in rats prevented esophagitis, preserved nutrition, and did not interfere with enterohepatic total bile acid circulation. 相似文献
3.
Murine thymus has been demonstrated to contain both cholinergic receptors and acetylcholinesterase activity. In the present study we have investigated the presence of the enzyme choline acetyltransferase in this organ, which is responsible for the synthesis of acetylcholine. Results reported here demonstrate that (1) an appreciable amount of the enzyme is already present in the thymus on the day of birth; (2) its expression is developmentally regulated; and (3) thymic atrophy, induced in young (2-week-old) and adult (6-week-old) mice by i.p. injection of hydrocortisone for 2 days, is accompanied by significant reduction of choline acetyltransferase activity only in young mice. Altogether these results demonstrate the presence in the murine thymus of functionally relevant markers of the cholinergic system that might interface the interactions between the nervous and immune systems. 相似文献
4.
Roberto Valcavi Michele Zini Simona Davoli Italo Portionli 《Clinical endocrinology》1992,37(4):360-364
OBJECTIVE: We have investigated the late GH rise occurring 3-5 hours after oral glucose administration. We have assessed the effect of endogenous cholinergic enhancement with pyridostigmine on the delayed GH rise following oral glucose loading in normal subjects. DESIGN: Placebo or 75 g oral glucose was given to the normal subjects 3 hours before 120 mg oral pyridostigmine or placebo. Four tests were carried out at random. (0 min) + placebo (180 min); test 2: glucose (0 min) + placebo (180 min); test 3: placebo (0 min) + pyridostigmine (180 min); test 4: glucose (0 min) + pyridostigmine (180 min). SUBJECTS: We studied eight normal subjects (four male and four female), ages 19-29 years, body mass indices 18-22 kg/m2. MEASUREMENTS: Plasma glucose and serum GH concentrations were measured for 6 hours after oral glucose or placebo administration. RESULTS: Pyridostigmine treatment significantly enhanced the GH releasing effect of prior (3 h) oral glucose. Late GH peak obtained by oral glucose loading rose from (mean +/- SEM) 17.4 +/- 4.6 to 37.2 +/- 9.0 mU/l (P < 0.05) after pyridostigmine, while GH peak following placebo plus pyridostigmine was 12.4 +/- 2.0 mU/l (P < 0.05 vs glucose plus pyridostigmine). The analysis of GH area under curves (AUCs) in the second phase of the tests (180-360 min) confirmed that glucose plus pyridostigmine released a greater amount of GH (4128 +/- 764 mU/l/3h) than glucose (1694 +/- 494 mU/l/3h, P < 0.001) or pyridostigmine alone (1292 +/- 150 mU/I/3h, P < 0.001). CONCLUSIONS: Pyridostigmine, an indirect cholinergic drug likely to inhibit somatostatin secretion from the hypothalamus, enhanced the late GH releasing activity of oral glucose. There is evidence that glucose suppresses plasma GH initially by increasing hypothalamic somatostatin release. This would result in an increase in the pituitary stores of GH. We propose that the delayed GH rise after oral glucose occurs when there is a fall in hypothalamic somatostatinergic tone; this is further reduced by the administration of pyridostigmine. At this time the pituitary stores of GH are released as a consequence of resumption of hypothalamic GHRH activity. This leads to the late GH rise. 相似文献
5.
Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight 总被引:6,自引:5,他引:6
Benjamin D. Levine James A. Pawelczyk rew C. Ertl James F. Cox Julie H. Zuckerman ré Diedrich Italo Biaggioni Chester A. Ray Michael L. Smith Satoshi Iwase Mitsuru Saito Yoshiki Sugiyama Tadaaki Mano Rong Zhang Kenichi Iwasaki Lynda D. Lane Jay C. Buckey Jr William H. Cooke Friedhelm J. Baisch David Robertson Dwain L. Eckberg C. Gunnar Blomqvist 《The Journal of physiology》2002,538(1):331-340
6.
A Bacia L Aloe M Fusco G Vantini A Leon B Oderfeld-Nowak 《Acta neurobiologiae experimentalis》1992,52(1):1-7
The cellular localization of the nerve growth factor-like immunoreactivity (NGF-LIR) has been studied in the intact adult rat brain at the level of the hippocampus and the septum. Immunolabelling for NGF combined with counterstaining with cresyl violet and double immunostaining technique, which allowed simultaneous localization of NGF-LIR and that of astroglial marker -GFAP, were used. The data indicate neuronal localization of NGF-like immunoreactivity and a lack of colocalization of NGF-LIR with the immunoreactivity of GFAP in the hippocampus. These data are consistent with in situ hybridization results for NGF and immunocytochemical results for pro-NGF localization obtained by others. At the septal level, apart from neuronal localization of NGF-LIR, single NGF-like immunoreactive astrocytes have been observed. This suggests that, although to a very small extent, in vivo intact brain astrocytes may, just as astrocytes growing in vitro, synthesize NGF-like molecules. This finding may be of importance in better understanding the trophic support for NGF responsive cholinergic neurones in the brain. 相似文献
7.
Siquini W Marmorale C Guercioni G Stortoni P Bearzi I Fianchini A Landia E 《Chirurgia italiana》2006,58(2):235-245
Solid pseudopapillary tumours of the pancreas (SPTP) are a distinct clinico-pathological entity that differs from the other cystic pancreatic neoplasms in the young age of onset, the almost exclusive incidence in the female sex and the low degree of malignancy. SPTP is a rare neoplasm that has shown a progressive increase of incidence, passing from 0.17%-2.7% of all exocrine tumours of the pancreas in the 1980's, to 6% in recent reports in 2003. In addition, it accounts for about 5% of cystic neoplasms of the pancreas. With the present paper, in the world literature, updated to August 2005, 887 cases have been described in 248 articles. The histogenesis of these epithelial neoplasms remains uncertain though it is likely that they originate from pluripotent immature pancreatic cells. The tumour is generally of large size and invariably presents a capsule. The diagnosis in most cases is based on compressive symptoms, pain or finding of a palpable mass, while in about 20% of the patients the finding is occasional during abdominal imaging performed for other pathologies. CT and MR are not always sufficient to differentiate with certainty between this type of tumour and other cystic neoplasms of the pancreas such as pseudocysts, parasitic cysts and congenital cysts. Cytological examination in most cases permits the diagnosis of SPTP. The malignancy of these neoplasms is attenuated and local with capsular invasion, lymp-node spread and, only rarely, liver and peritoneal metastases. The surgical treatment has to be radical since the malignancy can only be defined by postoperative histological examination. The treatment consists of three possible options: duodenocephalopancreatectomy, intermediate pancreatectomy, and distal pancreatectomy with or without splenectomy. Intraoperative histological examination is mandatory for the diagnostic confirmation and for the evaluation of negativity of the pancreatic resection margins. Survival after radical resection is excellent. Moreover, in forma metastasizing to the liver an aggressive attitude may be still curative and assure longer survival. The Authors report their experience with three female patients with an average age 18 years (28,19 and 8 years) operated on between 1995 and 2000 for SPTP. Two of the patients were asymptomatic and the finding of the tumour was occasional. The third patient presented jaundice and abdominal pain. The average diameter of the tumours was 6 cm (4, 7 and 7 cm). In all three cases tumour marker values (CEA, Ca19-9, alphaFP) were normal. Only in one case was the preoperative diagnosis correct. The surgical treatment depended on the location of the neoplasms: for the two tumours in the head, in one case an enucleoresection was performed in relation to an exophytic location, while, in the other, a duodenocephalopancreatectomy was performed. In the somatopancreatic tumour a distal splenopancreatectomy was performed. Only in one case (the DCP) the capsule and the surrounding parenchyma were infiltreted by neoplasm. In all cases there was immunohistochemical positivity for alpha1-antitrypsin and for neuron-specific enolase. Neither mortality nor operative morbidity were observed. Follow-up with CT found no relapses in any of the three patients after 5, 7 and 10 years, respectively, after the operation. 相似文献
8.
Antonio Haddad Tapias Filho Gustavo Bernardes de Figueiredo Oliveira Joo Italo Dias Frana Rui Fernando Ramos 《Arquivos brasileiros de cardiologia》2022,118(6):1006
Background Contemporary diagnosis of ACS and risk stratification are essential for appropriate management and reduction of mortality and recurrent ischemic events, in the acute phase of disease and after hospitalization. The Universal Definition of Myocardial Infarction recommends the detection of troponin levels above the 99th percentile.Objectives To evaluate the occurrence of early death and acute myocardial infarction (AMI) in patients without elevation of troponin (<0.034 ng/mL), patients with mild elevation (above the 99th percentile [>0.034 ng/mL and <0.12 ng/mL)], and patients with significant elevation of troponin (above the diagnostic cutoff for AMI defined by the troponin kit (≥0.12 ng/mL)]; and to analyze the impact of troponin on the indication for invasive strategy and myocardial revascularization.Methods Cross-sectional cohort study of patients with ACS with assessment of peak troponin I, risk score, prospective analysis of 30-day clinical outcomes and two-sided statistical tests, with statistical significance set at p<0.05.Results A total of 494 patients with ACS were evaluated. Troponin > 99th percentile and below the cutoff point, as well as values above the cutoff, were associated with higher incidence of composite endpoint (p<0.01) and higher rates of percutaneous or surgical revascularization procedures (p<0.01), without significative difference in 30-day mortality.Conclusions Troponin levels above the 99th percentile defined by the universal definition of AMI play a prognostic role and add useful information to the clinical diagnosis and risk scores by identifying those patients who would most benefit from invasive risk stratification and coronary revascularization procedures. 相似文献
9.
10.
Andrei Fodor Sara Broggi Elena Incerti Italo Dell’Oca Claudio Fiorino Ana M. Samanes Gajate Marcella Pasetti Mauro G. Cattaneo Paolo Passoni Luigi Gianolli Riccardo Calandrino Maria Picchio Nadia Di Muzio 《Clinical lung cancer》2019,20(1):e29-e38