全文获取类型
收费全文 | 12380篇 |
免费 | 1055篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 378篇 |
妇产科学 | 268篇 |
基础医学 | 1851篇 |
口腔科学 | 334篇 |
临床医学 | 1259篇 |
内科学 | 2266篇 |
皮肤病学 | 180篇 |
神经病学 | 1221篇 |
特种医学 | 474篇 |
外国民族医学 | 2篇 |
外科学 | 1924篇 |
综合类 | 123篇 |
一般理论 | 11篇 |
预防医学 | 935篇 |
眼科学 | 381篇 |
药学 | 711篇 |
中国医学 | 9篇 |
肿瘤学 | 1013篇 |
出版年
2023年 | 108篇 |
2022年 | 186篇 |
2021年 | 421篇 |
2020年 | 232篇 |
2019年 | 347篇 |
2018年 | 393篇 |
2017年 | 258篇 |
2016年 | 249篇 |
2015年 | 271篇 |
2014年 | 393篇 |
2013年 | 518篇 |
2012年 | 709篇 |
2011年 | 646篇 |
2010年 | 403篇 |
2009年 | 303篇 |
2008年 | 572篇 |
2007年 | 587篇 |
2006年 | 567篇 |
2005年 | 517篇 |
2004年 | 469篇 |
2003年 | 405篇 |
2002年 | 402篇 |
2001年 | 297篇 |
2000年 | 295篇 |
1999年 | 265篇 |
1998年 | 117篇 |
1997年 | 93篇 |
1996年 | 97篇 |
1995年 | 71篇 |
1994年 | 74篇 |
1993年 | 76篇 |
1992年 | 181篇 |
1991年 | 204篇 |
1990年 | 204篇 |
1989年 | 211篇 |
1988年 | 169篇 |
1987年 | 157篇 |
1986年 | 158篇 |
1985年 | 139篇 |
1984年 | 109篇 |
1983年 | 100篇 |
1982年 | 75篇 |
1980年 | 70篇 |
1979年 | 88篇 |
1978年 | 94篇 |
1977年 | 69篇 |
1974年 | 86篇 |
1973年 | 85篇 |
1972年 | 77篇 |
1971年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
S P Stringer J R Jordan W M Mendenhall J T Parsons N J Cassisi R R Million 《Otolaryngology--head and neck surgery》1992,107(3):395-398
The mandibular lingual releasing approach to oral cavity and oropharyngeal tumors provides excellent visualization for resection while integrity of the mandibular arch is preserved. A lingual floor-of-mouth flap is created, which allows delivery of these structures directly into the neck without lip splitting, mandibulotomy, or mandibulectomy. The procedure was carried out on 15 patients between 1987 and 1991, with followup ranging from 2 to 50 months. Nine patients had received previous radiation, whereas planned postoperative radiation was administered to five patients. The visualization afforded by this technique was very good, in that 12 patients had clear margins of resection. Three patients had close margins; recurrent disease developed in one of these patients 18 months later. Twelve of the patients were able to maintain their weight with an oral diet alone. Four postoperative fistulae occurred, three of these were in patients who had not been previously irradiated. The single fistula that did not spontaneously heal occurred in a patient who had received previous radiation and was also on long-term corticosteroids. Mandibular osteoradionecrosis developed in two patients who received postoperative radiation. The complication rate after previous radiation is acceptable; however, there is risk of mandibular osteoradionecrosis after high-dose postoperative radiation. 相似文献
52.
In human cortex and hippocampus area, [3H]5-HT (5 nM) labels 5-HT1A, 5-HT1D and 5-HT1E sites. After masking 5-HT1A receptors by 0.1 μM 8-OH-DPAT, the binding displaced by 0.1 μM 5-CT presumably represented 5-HT1D sites and the remaining binding 5-HT1E sites. In frontal cortex, 5-HT1A receptors represented the main binding in layers II and VI and a lower fraction on other layers. 5-HT1D and 5-HT1E sites, were more homogeneously distributed in layers II to VI (21–34% of specific [3H]5-HT binding). 5-HT1E sites were of similar affinities (KD close to 6–8 nM) in the cortical layers II to VI. In CA1 field of hippocampus, (pyramidal layer, stratum radiatum, molecular layer), CA2 and dentate gyrus, 5-HT1A receptors represented the major fraction, 5-HT1D sites a significant fraction and 5-HT1E a minor fraction of the specific [3H]5-HT binding. In CA3–CA4 fields, 5-HT1A receptors were less densely present, 5-HT1D sites were predominant and 5-HT1E sites represented a significant fraction (27%). The highest densities of 5-HT1E sites have been measured in subiculum, where 5-HT1A, 5-HT1D, and 5-HT1E binding sites were equally represented and in entorhinal cortex where 5-HT1E sites represented the major binding in layer III. They were also present in layers II and IV (29 and 24%) and, to a lesser extent, in layers V and VI. 5-HT1A sites were predominant in layer VI, II and V and were less abundant in other layers. 5-HT1D were homogeneously present in layers II, III, IV and were present in low amounts in other layers. No 5-HT1E were detected in choroid plexus, where [3H]5-HT was dramatically reduced by mesulergine (5-HT2C receptors). No significant displacement of [3H]5-HT by mesulergine was measured in other structures. 相似文献
53.
54.
Zoran Trajkovski Miodrag Vrcakovski Jordan Saveski Zoran S. Gucev 《American journal of medical genetics. Part A》2002,111(4):415-419
A second pregnancy of young, nonconsanguineous parents of Macedonian ethnic origin was examined by ultrasound. Polyhydramnios and hydrops fetalis were found as well as severe short limb, short stature, and cystic hygroma of the neck. An artificial abortion was performed at the age of 23 weeks. The radiological features included moth‐eaten severely shortened long bones and ectopic calcifications of long bones, vertebral column, ribs, pelvis, larynx, trachea. In addition, the fetus had large head with depressed nasal bridge, severe platyspondyly, and short barrel‐shaped trunk. Light microscopy demonstrated lack of chondrocyte columns and disorganization of the cartilaginous architecture. This is the seventh reported case of this rare form of lethal skeletal dysplasia. © 2002 Wiley‐Liss, Inc. 相似文献
55.
56.
RHAMM (Receptor for Hyaluronic Acid Mediated Motility) has been identified as a receptor for the extracellular matrix component hyaluronan (HA) and was recently shown to be essential for the locomotion of normal and transformed peripheral cells. Until now the potential role of RHAMM in the motility of neural-derived cells has not been investigated. Here, we report that cultured primary astrocytes, astrocyte cell lines, and microglia express this receptor and exhibit RHAMM-dependent motility. Immunocytochemical localization of RHAMM showed that it was often present as aggregates at the periphery of cells in contact with one another or concentrated on protruding processes of isolated cells. Glial cells contained 50 and 72 kDa forms of RHAMM, and both of these forms were found to have HA binding capacity. Time lapse imaging of cell locomotion revealed a significant inhibition of motility and process elongation by neutralizing anti-RHAMM antibodies and by peptides corresponding to the HA binding domains of RHAMM. These results demonstrate that RHAMM serves a role in glial cell locomotion in vitro and provide the basis for investigations of the motile behavior of glial cells in vivo after CNS injury. 相似文献
57.
S R Glaser 《Canadian Medical Association journal》1994,150(3):367-371
OBJECTIVE: To determine the extent to which sigmoidoscopy is used as an investigative tool by family physicians in Canada. DESIGN: Retrospective study of data from provincial and territorial health agencies for the fiscal year 1989. SETTING: Canada. PARTICIPANTS: All family physicians. MAIN OUTCOME MEASURES: Number of physicians in each province and territory who performed sigmoidoscopy (flexible and rigid), type of physician (generalist or specialist), number of procedures performed, fee schedule and number of physicians billing medicare in each province and territory. RESULTS: During the study period 3849 (15.1%) of all family physicians performed rigid sigmoidoscopy; the proportion varied from 3.4% (in Quebec) to 40.0% (in the Northwest Territories). A total of 43,914 rigid sigmoidoscopies were performed by family physicians, representing 23% of all such procedures. Flexible sigmoidoscopy was performed by 381 (1.5%) of all family physicians; the proportion varied from 0.4% (in Quebec) to 6.8% (in Prince Edward Island). A total of 5361 flexible sigmoidoscopies were performed, representing 6.0% of all such procedures. CONCLUSION: The proportion of Canadian family physicians who are using sigmoidoscopy, rigid or flexible, as a diagnostic tool is low. 相似文献
58.
Pharmacokinetics of two alternative dosage forms for cyclosporine: liposomes and intralipid 总被引:2,自引:0,他引:2
Cyclosporine (CsA), commercially available as iv or oral Sandimmune, is a potent immunosuppressant which can induce dose-related nephrotoxocity. In addition, the iv product contains a solubilizing agent, Cremophore EL, which in itself is reported to be nephrotoxic and can induce, in sensitized patients, anaphylactic reactions. Solubilization of CsA with liposomes or lipid emulsions could provide a suitable alternative dosage form for iv administration. With this in mind, male New Zealand white rabbits were given iv CsA (10 mg/kg) in three different dosage forms: (1) CsA:liposomes; (2) CsA:Intralipid (soybean oil and phospholipids); and (3) the commercially available Sandimmune (cyclosporine). The CsA concentration in whole blood samples was analyzed by HPLC. The terminal disposition half-life of CsA (t1/2 beta) ranged from 400 to 475 min and was not statistically different among the three groups. However, the distribution characteristics of CsA changed dramatically depending on the dosage form. The volume of distribution of CsA at steady state (Vdss) in Sandimmune was 2.7 +/- 0.2 L/kg and was significantly lower than that of either Intralipid (10.6 +/- 2.7 L/kg) or liposomes (7.4 +/- 2.3 L/kg). A significantly lower total body clearance (TBC) of CsA also was seen for Sandimmune (12.7 +/- 0.3 mL/min/kg) as compared with that of either Intralipid (24.4 +/- 8.2 mL/min/kg) or liposomes (18.9 +/- 3.9 mL/min/kg). Since CsA is extensively bound to lipoproteins, it is surprising that both test vehicles showed a different distribution pattern.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
59.
60.
Yueh-Wei Liu Allan M Concejero Chao-Long Chen Yu-Fan Cheng Hock-Liew Eng Tung-Liang Huang Tai-Yi Chen Chih-Chi Wang Shih-Ho Wang Chih-Che Lin Chee-Chien Yong Chin-Hsiang Yang Amornetta P Jordan Bruno Jawan 《Liver transplantation》2007,13(11):1545-1551
A pseudotumor, giant regenerative nodule, or macroregenerative nodule is an unusual benign hepatic lesion in biliary atresia (BA) patients. This tumor may mimic malignant transformation and may preclude liver transplantation (LT). The clinical and imaging surveillance of patients after the Kasai procedure is therefore an important aspect of management of BA patients. Our objective is to report our experience and describe the incidence, imaging, and pathologic features of pseudotumors in BA patients awaiting LT. From August 1990 to December 2006, 133 LTs for BA were performed. Five (3.8%; 4 female, 1 male) patients were diagnosed with pseudotumor. The patients' records were reviewed. The diagnostic imaging modalities used were abdominal ultrasound (US), computed tomography (CT) scan, and magnetic resonance imaging (MRI). Histologic confirmation of the lesions was obtained in all cases. All underwent the Kasai operation in early infancy. Six of 7 lesions in 4 of 5 patients were demonstrated by pretransplant imaging. Two of 7 tumors were detected by US. Five of 7 lesions were detected by CT, and 5 of 7 lesions were demonstrated by MRI. In 1 patient, the lesion was not seen in the US, CT, or MRI but was found during surgery and confirmed by histology. An additional tumor was found incidentally during histologic examination in a patient previously diagnosed to have 2 tumors by CT and MRI. In another patient diagnosed to have 2 tumors on imaging, pathology revealed only a single tumor. In conclusion, although unusual, pseudotumor should be included in the differential diagnosis of liver masses in BA children. 相似文献