全文获取类型
收费全文 | 842篇 |
免费 | 17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 | 7篇 |
基础医学 | 68篇 |
口腔科学 | 25篇 |
临床医学 | 63篇 |
内科学 | 263篇 |
皮肤病学 | 2篇 |
神经病学 | 118篇 |
特种医学 | 20篇 |
外科学 | 110篇 |
一般理论 | 2篇 |
预防医学 | 50篇 |
眼科学 | 9篇 |
药学 | 44篇 |
中国医学 | 1篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 17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 | 39篇 |
2012年 | 58篇 |
2011年 | 53篇 |
2010年 | 35篇 |
2009年 | 33篇 |
2008年 | 67篇 |
2007年 | 67篇 |
2006年 | 62篇 |
2005年 | 62篇 |
2004年 | 49篇 |
2003年 | 44篇 |
2002年 | 62篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1978年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1960年 | 2篇 |
1942年 | 1篇 |
1941年 | 2篇 |
1940年 | 1篇 |
1939年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有862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.
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
4.
Substance abuse and psychopathology 总被引:1,自引:0,他引:1
Massimo Clerici Italo Carta Carlo Lorenzo Cazzullo 《Social psychiatry and psychiatric epidemiology》1989,24(4):219-226
This report evaluates, using DSM III, the psychopathological profile of 226 heroin users taken in at the clinical centre of "Cascina Verde" Therapeutic Community (Milan, Italy) and admitted to a psychotherapeutic, retraining, integrated, both out-and-in-patient treatment. The outcome shows that 30% of subjects are to be diagnosed according to Axis I while 61% are to be considered among Axis II personality disorders. A portion of 16% is to be referred to the "schizophrenic spectrum", 25% has histrionic, narcissistic, antisocial and borderline personality disorders and the remaining are to be referred to an extremely heterogeneous category. The report shows also data concerning Axes IV and V, always according DSM III. 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.
Nissar A. Darmani Angelo A. Izzo Brian Degenhardt Marta Valenti Giuseppe Scaglione Raffaele Capasso Italo Sorrentini Vincenzo Di Marzo 《Neuropharmacology》2005,48(8):1154
The endogenous cannabimimetic compound, and anandamide analogue, N-palmitoyl-ethanolamine (PEA), was shown to exert potent anti-inflammatory and analgesic effects in experimental models of visceral, neuropathic and inflammatory pain by acting via several possible mechanisms. However, only scant data have been reported on the regulation of PEA levels during pathological conditions in animals or, particularly, humans. We review the current literature on PEA and report the results of three separate studies indicating that its concentrations are significantly increased during three different inflammatory and neuropathic conditions, two of which have been assessed in humans, and one in a mouse model. In patients affected with chronic low back pain, blood PEA levels were not significantly different from those of healthy volunteers, but were significantly and differentially increased (1.6-fold, P<0.01, N = 10 per group) 30 min following an osteopathic manipulative treatment. In the second study, the paw skin levels of PEA in mice with streptozotocin-induced diabetic neuropathic pain were found to be significantly higher (1.5-fold, P<0.005, N = 5) than those of control mice. In the third study, colonic PEA levels in biopsies from patients with ulcerative colitis were found to be 1.8-fold higher (P<0.05, N = 8–10) than those in healthy subjects. These heterogeneous data, together with previous findings reviewed here, substantiate the hypothesis that PEA is an endogenous mediator whose levels are increased following neuroinflammatory or neuropathic conditions in both animals and humans, possibly to exert a local anti-inflammatory and analgesic action. 相似文献
7.
Barbara Longobardi Elena De Martin Claudio Fiorino Italo Dell'oca Sara Broggi Giovanni Mauro Cattaneo Riccardo Calandrino 《Radiotherapy and oncology》2005,77(2):148-156
BACKGROUND AND PURPOSE: To investigate the feasibility and the advantages of using Intensity-Modulated Radiotherapy (IMRT) for the treatment of head-and-neck cancer. Comparing different methods to deliver IMRT in this clinical setting. MATERIALS AND METHODS: Seven patients (four radical; three post-operative), treated on a 6MV Varian Linac (equipped with an 80 leaves MLC) in accordance with a routine 3DCRT plan, were replanned. Original treatment plans were computed to irradiate a primary Planning Target Volume (PTV1, 54 Gy) and then to perform a boost on a PTV2 (radical: 70.2 Gy; post-operative: 64.8 Gy). IMRT dose plans were inversely-optimized using appropriate constraints with the Helios tool on a Varian Eclipse system. Once the optimal fluences were calculated, different modalities to deliver IMRT were considered: Sliding Window (SW) and Step and Shoot (SS) techniques using a different number of intensity levels to approximate the optimal fluences (e.g. 5, 10 and 20). Mean dose, maximum dose and a number of dose-volume parameters regarding CTV1, CTV2, PTV1, PTV2, OARs (spinal and planning spinal cord, parotids, optical structures, brain and temporal mandibular joint) were considered to compare the five modalities (3DCRT, SW, SS5, SS10, SS20); the Conformity Index (CI), the Irradiated Volume (IV) and the Treated Volume (TV) were also considered in the comparison. RESULTS: A more uniform coverage of the PTV in the IMRT dose plans with respect to the 3DCRT plan was found (for PTV2: V90% = 94.3 for 3DCRT, 97.6 for SS5, 98 for SS10 and 98.1 for SW; V107% = 20.7 for 3DCRT, 5.9 for SS5, 2 for SS10 and 1.3 for SW). Concerning OARs, they all present a significant reduction of mean and/or maximum dose and dose-volume patterns assessed from DVHs: in particular the mean dose of parotids decrease on average of about 13.5Gy passing from 3DCRT to IMRT with an average reduction of NTCP ranging from about 20% to more than 40% for radically treated patients, depending on the chosen end-point. IV and TV are also slightly smaller with IMRT. The results obtained with SS techniques employing 10 or more intensity levels are comparable with those obtained with SW; no differences between SS10 and SW may be appreciated when considering the DVHs of PTV, CTV and OARs. On the other hand, in some cases SS5 may be slightly sub-effective with respect to SS10-SW when considering PTV coverage and Dmax of the spinal cord. CONCLUSIONS: With the Varian planning and delivery system, Step-and-shoot approximations of inversely optimised fluences in head-neck IMRT compare well with SW delivery, even with only five intensity levels. With a number of intensity level of 10 or more, no differences can be appreciated in PTV coverage/OAR sparing with respect to SW. 相似文献
8.
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
9.
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
10.