全文获取类型
收费全文 | 4939篇 |
免费 | 440篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 72篇 |
妇产科学 | 67篇 |
基础医学 | 718篇 |
口腔科学 | 71篇 |
临床医学 | 482篇 |
内科学 | 1324篇 |
皮肤病学 | 85篇 |
神经病学 | 381篇 |
特种医学 | 162篇 |
外科学 | 740篇 |
综合类 | 156篇 |
一般理论 | 3篇 |
预防医学 | 289篇 |
眼科学 | 74篇 |
药学 | 184篇 |
中国医学 | 29篇 |
肿瘤学 | 532篇 |
出版年
2023年 | 35篇 |
2022年 | 50篇 |
2021年 | 125篇 |
2020年 | 67篇 |
2019年 | 89篇 |
2018年 | 139篇 |
2017年 | 80篇 |
2016年 | 92篇 |
2015年 | 140篇 |
2014年 | 173篇 |
2013年 | 198篇 |
2012年 | 278篇 |
2011年 | 294篇 |
2010年 | 163篇 |
2009年 | 168篇 |
2008年 | 254篇 |
2007年 | 280篇 |
2006年 | 269篇 |
2005年 | 261篇 |
2004年 | 254篇 |
2003年 | 241篇 |
2002年 | 168篇 |
2001年 | 170篇 |
2000年 | 132篇 |
1999年 | 108篇 |
1998年 | 38篇 |
1997年 | 36篇 |
1996年 | 46篇 |
1995年 | 29篇 |
1994年 | 34篇 |
1993年 | 21篇 |
1992年 | 77篇 |
1991年 | 76篇 |
1990年 | 73篇 |
1989年 | 68篇 |
1988年 | 55篇 |
1987年 | 56篇 |
1986年 | 56篇 |
1985年 | 51篇 |
1984年 | 33篇 |
1983年 | 41篇 |
1982年 | 28篇 |
1981年 | 33篇 |
1980年 | 25篇 |
1979年 | 33篇 |
1977年 | 19篇 |
1972年 | 23篇 |
1971年 | 16篇 |
1937年 | 41篇 |
1936年 | 38篇 |
排序方式: 共有5417条查询结果,搜索用时 15 毫秒
11.
TNF alpha and Fas mediate tissue damage and functional outcome after traumatic brain injury in mice.
Daniela Bermpohl Zerong You Eng H Lo Hyung-Hwan Kim Michael J Whalen 《Journal of cerebral blood flow and metabolism》2007,27(11):1806-1818
Tumor necrosis factor-alpha (TNFalpha) and Fas are induced after traumatic brain injury (TBI); however, their functional roles are incompletely understood. Using controlled cortical impact (CCI) and mice deficient in TNFalpha, Fas, or both (TNFalpha/Fas-/-), we hypothesized that TNFalpha and Fas receptor mediate secondary TBI in a redundant manner. Compared with wild type (WT), TNFalpha/Fas-/- mice had improved motor performance from 1 to 4 days (P<0.05), improved spatial memory acquisition at 8 to 14 days (P<0.05), and decreased brain lesion size at 2 and 6 weeks after CCI (P<0.05). Protection in TNFalpha/Fas-/- mice from histopathological and motor deficits was reversed by reconstitution with recombinant TNFalpha before CCI, and TNFalpha-/- mice administered anti-Fas ligand antibodies had improved spatial memory acquisition versus similarly treated WT mice (P<0.05). Tumor necrosis factor-alpha/Fas-/- mice had decreased the numbers of cortical cells with plasmalemma damage at 6 h (P<0.05 versus WT), and reduced matrix metalloproteinase-9 activity in injured brain at 48 and 72 h after CCI. In immature mice subjected to CCI, genetic inhibition of TNFalpha and Fas conferred beneficial effects on histopathology and spatial memory acquisition in adulthood (both P<0.05 versus WT), suggesting that the beneficial effects of TNFalpha/Fas inhibition may be permanent. The data suggest that redundant signaling pathways initiated by TNFalpha and Fas play pivotal roles in the pathogenesis of TBI, and that biochemical mechanisms downstream of TNFalpha/Fas may be novel therapeutic targets to limit neurological sequelae in children and adults with severe TBI. 相似文献
12.
13.
14.
15.
Splenic abscess. 总被引:1,自引:0,他引:1
L L Ooi R Nambiar A Rauff P O Mack T L Yap 《The Australian and New Zealand journal of surgery》1992,62(10):780-784
Isolated splenic abscess is an uncommon condition. Seven cases seen between 1980 and 1990 are reviewed. The clinical presentation is non-specific and diagnosis is usually delayed. Computerized tomography allowed for accurate diagnosis in all cases. Pseudomonas species as a causative organism is reported to be rare, but were present in three of the present cases. Antibiotic therapy alone is insufficient and splenectomy remains the treatment of choice. 相似文献
16.
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
17.
We have previously described the isolation and initial characterization of 15 kDa protein isoforms (p15s) from rabbit polymorphonuclear leukocytes (PMN) that bind toEscherichia coli and modulate the antibacterial actions of other leukocyte proteins on this gram negative organism. We now report that the p15s differ in primary structure. The cloning and sequencing of two distinct p15 cDNAs from a rabbit bone marrow library reveal that two of the isoforms are closely similar in primary structure differing at only two amino acid positions. The p15 cDNAs encode putative signal sequences suggesting a granule-associated localization for these proteins. Analysis of the derived p15 primary structures reveals homology to two leukocyte proteins: CAP-18, an 18 kD lipopolysaccharide (LPS) binding protein from rabbit PMN and cathelin, an 11 kD cysteine protease inhibitor from porcine leukocytes. This structural similarity suggests the existence of a novel family of low molecular weight leukocyte proteins with potential roles in inflammation. 相似文献
18.
Dr. Vera J.S. Van de Velde Ph.D. Dr. Achiel P. Van Peer Ph.D. Dr. Joseph J.P. Heykants Ph.D. Mr. Robert J.H. Woestenborghs Chem. Eng. Dr. Patricia Van Rooy M.D. Mr. Karel L. De Beule Dip. Hosp. Pharm. Dr. Geert F.M.J. Cauwenbergh Ph.D. 《Pharmacotherapy》1996,16(3):424-428
Study Objective . To compare the pharmacokinetics of a single 100-mg oral dose of itraconazole administered as 10 ml of a 10-mg/ml itraconazole solution in hydroxypropyl-β-cyclodextrin under fasting versus postprandial conditions. Design . Open-label, two-way, randomized, crossover study. Setting . Janssen Research Foundation, Belgium. Patients . Twelve healthy volunteers. Interventions . Blood samples were obtained for pharmacokinetic analyses immediately before dosing and at regular intervals up to 96 hours after each dose. Blood and urine samples were obtained for hematologic, biochemical, and urinary safety analyses at baseline and at the end of the study. Measurements and Main Results . The mean peak plasma concentrations of both itraconazole and its active metabolite hydroxy-itraconazole were significantly higher under fasting conditions than under postprandial conditions. The mean times to peak concentration for both the parent compound and its metabolite were significantly shorter under fasting than under nonfasting conditions. The mean areas under the curve (AUC0–∞ and AUC0–24 hrs) were also significantly higher under fasting than under postprandial conditions. Conclusions . Our findings suggest that the higher bioavailability of this new formulation of itraconazole may be of benefit in seriously ill patients who are not able to ingest adequate quantities of food. The fact that the solution was also well tolerated and was not associated with clinically significant changes in any laboratory value further underscores the potential utility of this dosing form. 相似文献
19.
S Sabanathan J Eng G N Pradhan 《Scandinavian journal of thoracic and cardiovascular surgery》1990,24(1):87-88
A case of spontaneous rupture of the oesophagus (Boerhaave's syndrome) following acute myocardial infarction is presented. Conservative management with chest drainage and parenteral, later jejunostomy, feeding was successful. Progress was monitored with methylene blue swallow. A review of the literature revealed only two previous cases of this type. 相似文献
20.
Adrian Ooi Narain Moorjani Giedrius Baliulis Barry R. Keeton Anthony P. Salmon James L. Monro Marcus P. Haw 《European journal of cardio-thoracic surgery》2006,30(6):917-922
Objective: To assess the impact of early corrective surgery on the short and medium term outcome in tetralogy of Fallot (TOF). Materials and methods: All patients under 12 months of age undergoing correction of isolated TOF between February 1997 and July 2003 were reviewed retrospectively. Outcome data for mortality, post-operative care management, major morbidity and clinical follow-up were analysed. Results: Fifty-two operations were performed. The mean age at surgery was 5 months (range 1–12) of whom 16 (30.8%) were less than 3 months old, including 2 neonates, 22 (42.3%) were 3–6 months old and 14 (26.9%) were 7–12 months old. There was 1 (1.9%) early death caused by a cerebro-vascular accident and 1 (1.9%) late death secondary to acute infective endocarditis. There were no differences in post-operative morbidities attributable to age. Patients under 3 months old required greater duration of post-operative ventilation, ITU stay and in-hospital stay. At a mean follow-up of 4.0 years (range 1.5–8.0), 33 (63.5%) patients had well-tolerated pulmonary regurgitation (PR) and 3 (5.8%) patients required re-operation for right ventricular outflow tract obstruction (RVOTO). All patients had right bundle-branch-block but with QRS < 150 ms. Conclusion: Early definitive repair of TOF can be performed safely on patients under 6 months old. Age at surgery does not appear to affect the medium term haemodynamic outcome. However, early surgery does escalate the need for ICU care. This data suggests repair in asymptomatic patients be delayed until 3–6 months of age. 相似文献