全文获取类型
收费全文 | 2299篇 |
免费 | 127篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 34篇 |
妇产科学 | 24篇 |
基础医学 | 272篇 |
口腔科学 | 109篇 |
临床医学 | 136篇 |
内科学 | 573篇 |
皮肤病学 | 9篇 |
神经病学 | 369篇 |
特种医学 | 110篇 |
外科学 | 338篇 |
综合类 | 8篇 |
一般理论 | 2篇 |
预防医学 | 101篇 |
眼科学 | 49篇 |
药学 | 161篇 |
中国医学 | 3篇 |
肿瘤学 | 118篇 |
出版年
2024年 | 3篇 |
2023年 | 21篇 |
2022年 | 35篇 |
2021年 | 70篇 |
2020年 | 45篇 |
2019年 | 75篇 |
2018年 | 79篇 |
2017年 | 43篇 |
2016年 | 77篇 |
2015年 | 75篇 |
2014年 | 104篇 |
2013年 | 103篇 |
2012年 | 196篇 |
2011年 | 209篇 |
2010年 | 111篇 |
2009年 | 103篇 |
2008年 | 171篇 |
2007年 | 164篇 |
2006年 | 152篇 |
2005年 | 124篇 |
2004年 | 127篇 |
2003年 | 111篇 |
2002年 | 71篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 13篇 |
1998年 | 12篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1976年 | 5篇 |
1974年 | 2篇 |
1965年 | 3篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1936年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有2435条查询结果,搜索用时 709 毫秒
141.
Aglietti P Giron F Buzzi R Biddau F Sasso F 《The Journal of bone and joint surgery. American volume》2004,(10):2143-2155
BACKGROUND: The choice of graft for anterior cruciate ligament reconstruction is a matter of debate, with patellar and hamstring tendons being the two most popular autologous graft options. The objective of this study was to determine in a prospective, randomized clinical trial whether two grafts (bone-patellar tendon-bone or doubled hamstring tendons) fixed with modern devices affect the two-year minimum clinical and radiographic outcomes of anterior cruciate ligament reconstruction. METHODS: One hundred and twenty patients with a chronic unilateral rupture of the anterior cruciate ligament underwent arthroscopically assisted reconstruction with use of either autologous bone-patellar tendon-bone or doubled hamstring tendon grafts, in a strictly alternating manner. Both groups were comparable with regard to demographic data, preoperative activity level, mechanism of injury, interval between the injury and the operation, and the amount of knee laxity present preoperatively. The same well-proven surgical technique and aggressive controlled rehabilitation was used. An independent observer, who was blinded with regard to the involved leg and the type of graft, performed the outcome assessment with use of a visual analog scale, the new International Knee Documentation Committee form, the Knee Injury and Osteoarthritis Outcome Score, the Functional Knee Score for Anterior Knee Pain, and an arthrometric and an isokinetic dynamometric evaluation. Radiographs were also made. RESULTS: At the two-year follow-up evaluation, no differences were found in terms of the visual analog score, the Knee Injury and Osteoarthritis Outcome Score, the new International Knee Documentation Committee subjective and objective evaluation scores, the KT-1000 side-to-side laxity measurements, the Functional Knee Score for Anterior Knee Pain, muscle strength recovery, or return to sports activities. In the bone-patellar tendon-bone group, we found a higher prevalence of postoperative kneeling discomfort (p < 0.01) and an increased area of decreased skin sensitivity (p < 0.001). In the hamstring tendon group, we recorded a higher prevalence of femoral tunnel widening (p < 0.01). In this group, a correlation was also found between medial meniscectomy and an increased prevalence of pivot-shift glide (p = 0.035). CONCLUSIONS: We believe that, with use of accurate and proven surgical and rehabilitation techniques, both grafts are an equivalent option for anterior cruciate ligament reconstruction. 相似文献
142.
Ferraraccio F Esposito S Santé P Cerasuolo F Agozzino M Agozzino M Cotrufo M Agozzino L 《Ultrastructural pathology》2004,28(3):137-140
The study of cystic cavities and collagen fibers fragmentation is useful to for a better knowledge of pathogenesis and surgical therapy of medial ascending aortic degeneration. Thus, the aim of this study was to describe by scanning electron microscopy the surfaces and shape of the cysts, measure their area, and identify microcystic spaces related to this degenerative disease. Scanning electron microscopy analysis was performed in 16 out of 36 patients who underwent surgery for ascending aorta dilatation with associated aortic valve disease. The aortic medial wall showed a cribrose appearance at low magnification (×50-100) and the intima was effuse. At high magnification (×500-2000), small cavities (clefts) lined by normal or fragmented elastic fibers and large cavities (pseudocystes) with anfractuous borders lined by fragmented elastic fibers and smooth muscle cells were observed. Furthermore, in the outer media wall microvessels lined by endothelium were also observed. These changes were lacking or less pronounced in normal aorta. SEM allows one to better identify the pathological cavities and to differentiate them from microvessels. These pathological cavities are more numerous and larger in the convexity than in the concavity of the aorta in according to our previous morphological and morphometric findings in asymmetrical aorta dilatation. 相似文献
143.
Arpicco S Canevari S Ceruti M Galmozzi E Rocco F Cattel L 《Il Farmaco; edizione pratica》2004,59(11):869-878
We synthesized new cationic lipids, analogue to N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA) and 1,2-dimyristyloxypropyl-3-dimethyl-hydroxyethylammonium bromide (DMRIE), in order to compare those containing a dodecyl chain with those having a relatively long chain with two or five double bonds, such as squalenyl and dihydrofarnesyl derivatives, or complex saturated structures, such as squalane derivatives. The fusogenic helper lipid dioleoylphosphatidylethanolamine (DOPE) was added to cationic lipids to form a stable complex. Liposomes composed of 50:50 w/w cationic lipid/DOPE were prepared and incubated with plasmidic DNA at various charge ratios and the diameter and zeta potential of the complexes were measured. The surface charge of the DNA/lipid complexes can be controlled by adjusting the cationic lipid/DNA ratio. Finally, we tested the in vitro transfection efficiency of the cationic lipid/DNA complexes using different cell lines. The transfection efficiency was highest for the dodecyloxy derivative containing a single hydroxyethyl group in the head, followed by the dodecyloxy and the farnesyloxy trimethylammonium derivatives. Instead the C27 squalenyl and C27 squalanyl derivatives resulted inactive. 相似文献
144.
Casali PG Messina A Stacchiotti S Tamborini E Crippa F Gronchi A Orlandi R Ripamonti C Spreafico C Bertieri R Bertulli R Colecchia M Fumagalli E Greco A Grosso F Olmi P Pierotti MA Pilotti S 《Cancer》2004,101(9):2086-2097
BACKGROUND: To the authors' knowledge, no effective medical therapy currently is available for advanced chordoma. Imatinib mesylate is a tyrosine kinase inhibitor targeting platelet-derived growth factor receptor-beta (PDGFRB), BCR-ABL, and KIT. METHODS: Six patients with advanced chordoma were treated with imatinib mesylate at a dose of 800 mg daily. In all patients, the tumor was found to be positive for PDGFRB, and in four patients PDGFRB was shown to be phosphorylated/expressed. RESULTS: After a treatment period of > or = 1 year, overt tumor liquefaction was evident on computed tomography (CT) scan in the first patient. In previous months, a decrease in contrast enhancement on magnetic resonance imaging (MRI) and a decrease in glucose uptake on positron emission tomography (PET) were detected. Similar signs on MRI and PET were observed in subsequent patients, who had a shorter treatment period. One of these patients initially was removed from therapy and then was readmitted to therapy because of difficulties with regard to tumor response assessment; 1 month after the reinitiation of therapy, an overt decrease in tumor density was visible on CT scan in this patient. In four of five symptomatic patients, a subjective improvement was observed early in the course of treatment. The first patient died after 17 months, with a sizeable, mostly liquefied mass. Another patient died early, apparently of unrelated causes. The remaining patients were on therapy at the time of last follow-up. CONCLUSIONS: Imatinib mesylate has been found to have antitumor activity in patients with chordoma. This activity might be mediated by inactivation of PDGFRB. Tumor response manifests through patterns that are similar to those observed in patients with gastrointestinal stromal tumors who respond to molecular-targeted therapy, but evolves more slowly. The benefit to the patient entailed by this pattern of tumor response in chordoma needs to be elucidated, but may be limited in the presence of significant local disease. 相似文献
145.
Vitali P Nobili F Raiteri U Canfora M Rosa M Calvini P Girtler N Regesta G Rodriguez G 《Psychiatry research》2004,130(1):97-107
This article describes the unusual case of a 60-year-old woman suffering from pure progressive aphemia. The fusion of multimodal neuroimaging (MRI, perfusion SPECT) implicated the right frontal lobe, especially the inferior frontal gyrus. This area also showed the greatest functional MRI activation during the performance of a covert phonemic fluency task. Results are discussed in terms of bihemispheric language representation. The fusion of three sets of neuroimages has aided in the interpretation of the patient's cognitive brain dysfunction. 相似文献
146.
Kapczinski F Frey BN Zannatto V 《Revista brasileira de psiquiatria (S?o Paulo, Brazil : 1999)》2004,26(Z3):17-21
Despite recent efforts to understand the neurobiology of Bipolar Disorder (BD), the exact pathophysiology remains undetermined. Due to the effects of various psychopharmacological agents, initial research focused on the study of biogenic amines. Recent evidence has shown that dysfunction in intracellular signaling systems and gene expression may be associated with BD. These alterations may cause interruptions in mood regulating circuits such as the limbic system, striatum and prefrontal cortex, and the neuroprotective effects of mood stabilizers may reverse this pathological process. This study aims to update the recent findings relative to the neurochemistry of BD. 相似文献
147.
148.
Glucose-based total parenteral nutrition does not stimulate glucose uptake by humans tumours 总被引:2,自引:0,他引:2
Bozzetti F Gavazzi C Mariani L Crippa F 《Clinical nutrition (Edinburgh, Scotland)》2004,23(3):417-421
BACKGROUND: Since glucose represents the preferred fuel for cancer cells, there is some debate about the potential stimulation of tumour metabolism induced by a glucose-based total parenteral nutrition (TPN) in cancer patients. METHODS: We investigated the uptake of [18]2-fluoro-2-deoxy-D-glucose (FDG) through the positron emission tomography of the healthy liver and of the tumour in 12 patients with liver metastases from colorectal cancer. We determined whether FDG uptake by the tumour in fasting conditions was affected by the subsequent administration of a glucose-based (GTPN) or a lipid-based (LTPN) containing glucose 4 mg/kg/min or lipid 2 mg/kg/min, respectively, as non-protein energy source. RESULTS: The data showed that FDG uptake by the metastases was 3-3.6 times higher than by the healthy liver in fasting conditions and it was not significantly affected by the subsequent administration of GTPN or LTPN. CONCLUSIONS: We speculated that, despite glucose being the preferred fuel for cancer cells, its disproportionately high uptake even in fasting conditions makes the glucose consumption unable to be modulated by a further supply of glucose or lipid. 相似文献
149.
Effects of long-term administration of Senna occidentalis seeds in the large bowel of rats 总被引:3,自引:0,他引:3
Nadal SR Calore EE Manzione CR Puga FR Perez NM 《Pathology, research and practice》2003,199(11):733-737
Plants of the genus Senna that contain anthranoides derivatives are frequently used as cathartics. Radiological studies have demonstrated that patients with chronic constipation who have used stimulant laxative have colonic redundancy and dilatation more frequently than patients who have not. The objective of the present work was to study morphological and histochemical changes of the lower gut after administration of Senna occidentalis seeds for a long period to rats, as observed in skeletal muscle fibers. Fragments of the lower gut of young and adult rats treated with S. occidentalis seeds (2% for 171 days and 3% for 61 days in the diet) were submitted to histological and histochemical analysis and to densitometry. The most important finding was decreased oxidative enzyme activity in smooth muscle cells and in myenteric neurons of the large bowel. As oxidative metabolism is essential for ATP and energy production, these results suggest that the functional intestinal disturbance caused by the chronic use of Senna occidentalis as a laxative can be due to a metabolic effect involving energy production, which would decrease colonic motility and cause functional colonic dilatation, but without any irreversible anatomic change. 相似文献
150.
We studied the effects of tryptophan (TRP) availability on the synthesis and release of nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) in interferon-gamma (IFN-gamma)-activated murine macrophages of the BAC1.2F5 cell line. IFN-gamma (100 U/ml) not only increased the synthesis and release of NO and TNF-alpha from these cells but also induced indoleamine-2,3-dioxygenase, the rate-limiting enzyme of TRP catabolism. This led to an increased metabolic flow through the kynurenine pathway and significantly decreased TRP levels in macrophage incubation media. Low TRP concentrations in the media, however, modified IFN-gamma effects. In TRP-"starved" cultures, in fact, the IFN-gamma-mediated NO synthase induction was significantly reduced, and the increased TNF-alpha synthesis and release were not affected. Our results suggest that a reduced local TRP availability may modify macrophage function and possibly the outcome of immune responses. 相似文献