全文获取类型
收费全文 | 2664篇 |
免费 | 60篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 79篇 |
妇产科学 | 138篇 |
基础医学 | 345篇 |
口腔科学 | 22篇 |
临床医学 | 152篇 |
内科学 | 538篇 |
皮肤病学 | 130篇 |
神经病学 | 233篇 |
特种医学 | 62篇 |
外科学 | 449篇 |
综合类 | 3篇 |
预防医学 | 126篇 |
眼科学 | 76篇 |
药学 | 123篇 |
中国医学 | 1篇 |
肿瘤学 | 200篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 18篇 |
2012年 | 159篇 |
2011年 | 217篇 |
2010年 | 54篇 |
2009年 | 42篇 |
2008年 | 320篇 |
2007年 | 347篇 |
2006年 | 331篇 |
2005年 | 312篇 |
2004年 | 273篇 |
2003年 | 282篇 |
2002年 | 188篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 27篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2725条查询结果,搜索用时 0 毫秒
991.
E F Lhoste V Ouriet S Bruel J-P Flinois C Brézillon J Magdalou C Chèze L Nugon-Baudon 《Food and chemical toxicology》2003,41(5):695-702
As other xenobiotics, polyphenols are metabolized both by the endogenous detoxication system and the gut microflora. We hypothesized that the presence of a gut microflora may account for the effect of catechins on phase I and II xenobiotic-metabolizing enzymes and that the human bacterial metabolites may be different from those of a rodent gut microflora. Therefore, the effects of 2% (+)-catechin or 2% (-)-epicatechin were studied in germ free (GF) rats and rats inoculated with the flora of a human volunteer (HFA). In addition, the catechins were administered in ethanol as a vehicle. In the liver, (+)-catechin or (-)-epicatechin decreased the total amount of CYP450 in both GF and HFA rats while the isoenzyme CYP2E1 decreased. In GF rats only, CYP2C11 increased when compared to the rats treated with the vehicle alone. (+)-catechin increased the specific activity of UGT-chloramphenicol in GF rats only and that of cytosolic glutathion-S-transferase (GST) in HFA rats only. In the intestine, (+)-catechin and (-)-epicatechin increased the specific activity of UGT-4-methylumbelliferone in both GF and HFA rats and that of UGT- chloramphenicol in HFA rats only. In conclusion, the presence of a human flora in rats is able to modify the inducing effect of catechins on the UGT and GST activities suggesting the involvement of bacterial metabolites. The alterations on CYP 450 are independent of the presence of a human gut flora. 相似文献
992.
F. De Jonge L. Van Nassauw J. G. De Man † B. Y. De Winter † F. Van Meir I. Depoortere ‡ T. L. Peeters ‡ P. A. Pelckmans † E. Van Marck§ & J-P. Timmermans 《Neurogastroenterology and motility》2003,15(2):149-159
Intestinal schistosomiasis is accompanied by motility-related dysfunctions but the underlying mechanisms are not well-known. Therefore, the presence and effects on intestinal contractility of somatostatin (SOM) and its receptor, SSTR2A, were investigated in the ileum of normal and infected mice. The distribution of SOM and SSTR2A was visualized using immunocytochemistry. Radioimmunoassay combined with oogram studies was performed to determine SOM levels and contractility measurements were determined in organ bath experiments. Schistosomiasis resulted in a significant decrease in somatostatin-positive endocrine cells, whereas the number of somatostatin-immunoreactive (IR) neuronal cell bodies did not change. From 8 weeks postinfection onwards, an increase was noted in somatostatin-IR nerve fibres in both villi and granulomas. The staining intensity for SSTR2A, expressed in somatostatin-negative myenteric cholinergic neurones, increased during infection suggesting an upregulation of this receptor. SOM levels were negatively correlated with the number of eggs during the acute phase, and were elevated during the chronic phase. Pharmacological experiments revealed that schistosomiasis diminished the inhibitory effect of SOM on neurogenic contractions. We can conclude that schistosomiasis influences the distribution and expression levels of SOM and SSTR2A in the murine ileum, which might explain the changed motility pattern. 相似文献
993.
G Plat P Pierard A Haller J Hutsebaut J Faber M Dusart P Eisendrath J-P Sculier V Ninane 《The European respiratory journal》2006,27(2):276-281
Positron emission tomography with 18F-fluoro-2-deoxy-d-glucose (FDG-PET) is more accurate than computed tomography for staging of mediastinal (hilar) lymph nodes. In the case of positive findings, tissue sampling of lymph nodes is required. The diagnostic/staging yield of transbronchial needle aspiration (TBNA) following endobronchial ultrasound (EBUS) localisation was assessed in this particular clinical setting. The number of avoided surgical procedures was evaluated. All consecutive patients referred for staging and/or diagnosis of mediastinal FDG-PET positive lesions were included. Data were prospectively collected. TBNA sampling of lymph nodes was performed after EBUS localisation. If no diagnosis was reached, further surgical sampling or adequate follow-up was performed. From January 2003 to June 2004, 33 patients were included. The average number of TBNA samples per patient was 4.2+/-1.5. Cytological or histological diagnoses were obtained in 27 (82%) of the patients, of which 78% were obtained after previous EBUS localisation. In 25 (76%) of the 33 patients, surgical staging procedures were suppressed. In conclusion, transbronchial needle aspiration after endobronchial ultrasound localisation should be considered as a primary method of evaluation of lymph nodes positive by positron emission tomography with 18F-fluoro-2-deoxy-d-glucose, and may replace the majority of surgical mediastinal staging/diagnostic procedures. 相似文献
994.
F Sleilati D Maladry L Doursounian J-P Lemerle 《British journal of plastic surgery》2003,56(5):509-514
Thumb reconstruction following amputation is usually performed in order to restore function. Nevertheless, the reconstruction should be cosmetically acceptable in order to be fully functional, and, in some cases, reconstructive surgery may be justified for purely aesthetic reasons. The most satisfying aesthetic results in adults are obtained with microsurgical partial great-toe transfer. The technique that we use for thumb reconstruction is illustrated by two case reports: that of a 26-year-old female patient and that of a 35-year-old male patient. Both patients had a distal thumb amputation with destroyed nail apparatus, and both sought thumb reconstruction for cosmetic reasons. Aesthetic reconstruction was performed in both cases with a partial ipsilateral great-toe transfer, composed of nail apparatus, underlying bone and custom-made pulp tissue. The vascular anastomosis was done at the snuff-box, through a small incision, with an exteriorised pedicle. The result was satisfactory in both cases, with minimal donor-site sequelae. Partial toe transfer has proven to be a reliable technique for thumb reconstruction. It is an evolving technique. Many modifications have been introduced to optimise the aesthetic result and to reduce donor-site morbidity. Our technique allows us to restore thumb length, replace the missing nail and reconstruct the pulp, with acceptable sequelae at the donor toe. The exteriorised-pedicle technique prevents pedicle compression and twisting and reduces scarring and stiffness. It does, however, require delicate postoperative care and a second procedure for pedicle division. 相似文献
995.
996.
R Joassin M Donnay J Hugé J-P Brasseur 《Annales de Réadaptation et de Médecine Physique》2006,49(8):577-580
997.
998.
The purpose of the present review is to assess the evidence published in scientific literature that industrial organic solvents as a generic group have the ability to induce long-term nervous system damage in workers that can be detected by techniques other than neuropsychological testing. The main body of evidence considered in this review was 40 studies involving the use of brain imaging, neurophysiological testing, gross autopsy or histopathology in groups of workers with long-term solvent exposure. Case reports involving both solvent abuse and occupational exposure, and experimental animal data have also been reviewed as supporting data. A number of the studies in groups of workers provide evidence of the presence of marginal atrophic abnormalities in the brain or deficits in nerve conduction velocity in solvent-exposed workers. However, there are limitations in the design of many of these studies, the strength of association between exposure and effect is not consistently strong, no dose-response relationship can be detected, the reported changes lack specificity and there is no coherence between the human and experimental animal data. Overall, it is not possible to draw reliable conclusions with respect to the presence or absence of nervous system damage related to the common properties of organic solvents. 相似文献
999.
We describe a young woman who developed left ventricular failure and pulmonary edema during fulminant onset of multiple sclerosis. One of the numerous plaques was located in the the left inferior cerebellar peduncle near the dorsal motor vagal and solitary tract nuclei. Within two days pulmonary edema had cleared, and within three days left ventricular function was normal. To our knowledge, left ventricular failure has not earlier been verified in acute multiple sclerosis. 相似文献
1000.