全文获取类型
收费全文 | 241篇 |
免费 | 2篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 32篇 |
妇产科学 | 7篇 |
基础医学 | 10篇 |
口腔科学 | 2篇 |
临床医学 | 20篇 |
内科学 | 58篇 |
皮肤病学 | 3篇 |
神经病学 | 24篇 |
特种医学 | 1篇 |
外科学 | 40篇 |
综合类 | 2篇 |
预防医学 | 6篇 |
眼科学 | 3篇 |
药学 | 16篇 |
肿瘤学 | 8篇 |
出版年
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1984年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1959年 | 11篇 |
1958年 | 27篇 |
1957年 | 31篇 |
1956年 | 28篇 |
1955年 | 23篇 |
1954年 | 25篇 |
1953年 | 1篇 |
1949年 | 1篇 |
1948年 | 3篇 |
排序方式: 共有243条查询结果,搜索用时 661 毫秒
1.
GAETANO BARBATO GABRIELLA D'AURIA LIVIO PAOLILLO GIANCARLO ZANOTTI 《Chemical biology & drug design》1991,37(5):388-398
Bycyclic peptides are useful model molecules that can mimic the constrained local folding of a great number of natural peptides and proteins, such as ionophoric peptides, enzyme active site, and ligand-receptor active site. The synthesis of the bicyclic title compound with the liquid phase method is described with experimental details. Of particular interest is the heterodetic closure of the second ring. The peptide showed a complexing activity with metal cations like Ba2+, Ca2+, and Mg2+ . The free bicyclic peptide conformation in solution has been studied by means of NMR spectroscopy and a plausible structure model worked out with model building on NMR constraints is proposed. 相似文献
2.
JUAN C. DE LA TORRE MARGARET MALLORY MICHELLE BROT LISA GOLD GEORGE KOOB MICHAEL B. A. OLDSTONE ELIEZER MASLIAH 《Virology》1996,220(2):508
Neurons have a restricted expression of MHC heavy chain molecules which prevents presentation of antigens of infecting viruses. As a result, such infected cells escape immune surveillance and allow the establishment of noncytolytic persistent infection. Here we show that a chronic noncytolytic viral infection bothin vitroandin vivoselectively perturbed the expression of GAP-43, a protein that plays a central role in neuronal plasticity processes accompanying learning and memory. GAP-43 expression was greatly decreased in the hippocampus, an area of heightened viral replication, while synaptic density was preserved. Concurrently, the ability to learn tasks was significantly impaired in these persistently infected mice. Yet, infected neurons remained free from structural injury. 相似文献
3.
Lack of Influence of Atrioventricular Delay on Stroke Volume at Rest in Patients with Complete Atrioventricular Block and Dual Chamber Pacing 总被引:1,自引:0,他引:1
ERALDO OCCHETTA CRISTINA PICCININO GABRIELLA FRANCALACCI REA MAGNANI LEONARDO BOLOGNESE PAOLO DEVECCHI GIORGIO ROGNONI PAOLO ROSSI 《Pacing and clinical electrophysiology : PACE》1990,13(7):916-926
Dual chamber pacing (DDD) maintains atrioventricular (AV) sequence; AV delay programmability modifies the relationship between atrial and ventricular contraction. To evaluate the hemodynamic effects of such a modification, ten patients with a DDD unit for complete AV block were studied by time-motion (M-mode) and Doppler echocardiography during inhibited ventricular pacing (VVI), atrial-triggered ventricular pacing (VDD) and atrioventricular sequential pacing (DVI) at different AV delay (90, 140, 190, 240 msec). A significant improvement in stroke volume (SV) (15%-20%, P less than 0.05) was seen during DDD versus VVI pacing; no changes, however, were observed in the same patient with different AV delay or during DVI versus VDD pacing. These data suggest that programming of AV delay does not affect systolic performance at rest; longer diastolic filling times recorded during DDD pacing with "short" AV delay (90-140 msec) do not seem to be a hemodynamically relevant epi-phenomenon of PM programming. 相似文献
4.
5.
R. F. SOUZA C. R. LELES G. H. GUYATT C. B. PONTES M. P. DELLA VECCHIA F. D. NEVES 《Journal of oral rehabilitation》2010,37(3):202-208
Summary The use of seven domains for the Oral Health Impact Profile (OHIP)‐EDENT was not supported for its Brazilian version, making data interpretation in clinical settings difficult. Thus, the aim of this study was to assess patients’ responses for the translated OHIP‐EDENT in a group of edentulous subjects and to develop factor scales for application in future studies. Data from 103 conventional and implant‐retained complete denture wearers (36 men, mean age of 69·1 ± 10·3 years) were assessed using the Brazilian version of the OHIP‐EDENT. Oral health‐related quality of life domains were identified by factor analysis using principal component analysis as the extraction method, followed by varimax rotation. Factor analysis identified four factors that accounted for 63% of the 19 items total variance, named masticatory discomfort and disability (four items), psychological discomfort and disability (five items), social disability (five items) and oral pain and discomfort (five items). Four factors/domains of the Brazilian OHIP‐EDENT version represent patient‐important aspects of oral health‐related quality of life. 相似文献
6.
GIUSEPPE MAGLIULO CLAUDIO UNGARI CARLO DELLA ROCCA MASSIMO MUSCATELLO GIANLUCA MARIA VINGOLO 《Clinical otolaryngology》1991,16(5):483-487
The aim of this paper was to investigate the effect of glycerol on experimental endolymphatic hydrops in guinea-pigs. The right endolymphatic sac and duct were obliterated through an extradural posterior fossa approach. Some animals received a 3 g/kg dose of glycerol for a period of 7 days, whereas others received the same dose for 30 days. The activity of glycerol was studied by investigating the volumetric changes in the scala media determined with a computerized planimeter. Glycerol induced a significant reduction of the hydrops showing its effectiveness and suggesting a strial metabolic response. 相似文献
7.
8.
GABRIELLA AGNOLETTI M.D. Ph.D. ROBERTO BORDESE M.D. ANTONELLA CORLETO M.D. FULVIO GABBARINI M.D. DAVIDE MARINI M.D. 《Journal of interventional cardiology》2012,25(6):622-627
Background: Total cavopulmonary connection (TCPC) is performed in patients having a single ventricle to allow the passive flow of systemic venous blood to the lungs. Interventional catheterization is needed to treat residual defects or complications. Aims: We discuss our results concerning 68 patients who had had TCPC from January 1995 to December 2010. Methods: Initial and follow‐up catheterization data were reviewed retrospectively. Mid ‐ term results were evaluated by means of angiography and/or CT scan. Results: Mean age at TCPC was 5 years (2.5–18); mean interval between TCPC and catheterization was 5.6 years (1.5–15). Sixty‐nine catheterizations were performed in 53 patients. Eleven patients (21%) had low venous pressure, did not display a right‐to‐left shunt, and did not need any intervention. Fifteen patients (28%) had low venous pressure and only needed the closure of the fenestration. The remaining 27 patients (51%) needed the following interventions: embolization of venous vessels prompting right‐to‐left shunt (n = 15), stenting or reconnection of pulmonary arteries (n = 5), stenting or recanalization of systemic veins (n = 11), other procedures (n = 5). In 3 patients the fenestration could not be closed due to high venous pressure. After the interventions oxygen saturation increased from 90.5%± 4.8% to 94.7%± 3.6% (P = 0.002). Conclusions: Our data show that 49% of patients with TCPC are in good condition late after surgery. However, half of these patients continue to need interventions generally aimed at suppressing stenoses at various levels of TCPC or at occluding vessels prompting right‐to‐left shunt. This population should enter a multicenter program aimed at identifying patients at risk. (J Interven Cardiol 2012;25:622–627) 相似文献
9.
PIETRO AMODEO GABRIELLA SAVIANO GIANFRANCO BORIN ANDREA CALDERAN PAOLO RUZZA TEODORICO TANCREDI 《Chemical biology & drug design》1998,51(3):180-187
To investigate the conformational flexibility of metal-complexed cyclodecapeptides, we synthesized and studied two antamanide analogs, in which the phenylalanine residue in position 6 or 9 of the sequence was substituted by Gly. Previous conformational studies on antamanide suggested that these backbone regions are affected by conformational variation. The NMR conformational study showed a high degree of flexibility for the two analogs. With sodium ions, on the other hand, [Gly9]. -antamanide was able to form a fairly stable equimolar complex, whereas [Gly6]. -antamanide showed a conformational heterogeneity, with one prevailing conformer. For the [Gly9]. -antamanide analog, the whole NMR data, combined with extensive theoretical calculations, were consistent with the presence of 1) two (β-turns of type I, centered on Gly9-Phe10 and Ala4-Phe5, respectively; 2) a central cavity with a six-carbonyl oxygen cage, optimal for a Na+ hexacoordination; 3) strongly H-bonded amide protons for residues 1 and 6, both involved in the formation of the two type I β-turns, which, however, exhibited some fluctuations during the molecular dynamics simulations. For the [Gly6]. -antamanide-Na+ complex the prevailing conformer was consistent with a more open structure, with the partial solvent exposure of all the amide protons; that is, the Gly residue in position 6 increases the flexibility of this critical site more than does the Gly in position 9. These data in some way parallel the results of the cytotoxicity tests on B16-F10 transformed cells for the two analogs: [Gly9]. -antamanide is cytotoxic after 48 h exposure, whereas [Gly6]. -antamanide is almost inactive. On the contrary, both analogs are practically inactive in vivo against phalloidin. 相似文献
10.
NICOLA MONDAINI GIANLUCA GIUBILEI GABRIELLA NESI REA BONGINI LUCIA ROBERTA GIRARDI ROBERTO PONCHIETTI 《International journal of urology》2005,12(8):763-764
We present a case of ureteral metastasis from a primary breast cancer where the disease recurred with an episode of renal colic 7 years after diagnosis. A surgical operation was performed to remove the terminal ureter and the perimeatal area of the urinary bladder. Urological and radiological outcome was satisfactory after a 2-year follow up. 相似文献