全文获取类型
收费全文 | 1539篇 |
免费 | 103篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 77篇 |
妇产科学 | 11篇 |
基础医学 | 153篇 |
口腔科学 | 17篇 |
临床医学 | 103篇 |
内科学 | 482篇 |
皮肤病学 | 22篇 |
神经病学 | 140篇 |
特种医学 | 36篇 |
外科学 | 301篇 |
综合类 | 20篇 |
预防医学 | 50篇 |
眼科学 | 52篇 |
药学 | 63篇 |
中国医学 | 1篇 |
肿瘤学 | 105篇 |
出版年
2023年 | 11篇 |
2022年 | 16篇 |
2021年 | 38篇 |
2020年 | 24篇 |
2019年 | 40篇 |
2018年 | 44篇 |
2017年 | 27篇 |
2016年 | 34篇 |
2015年 | 38篇 |
2014年 | 73篇 |
2013年 | 77篇 |
2012年 | 110篇 |
2011年 | 110篇 |
2010年 | 56篇 |
2009年 | 51篇 |
2008年 | 94篇 |
2007年 | 93篇 |
2006年 | 97篇 |
2005年 | 83篇 |
2004年 | 81篇 |
2003年 | 90篇 |
2002年 | 70篇 |
2001年 | 22篇 |
2000年 | 28篇 |
1999年 | 29篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 16篇 |
1991年 | 28篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 22篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1941年 | 2篇 |
排序方式: 共有1662条查询结果,搜索用时 15 毫秒
1.
Oren N Gottfried Steven Chin H Christian Davidson William T Couldwell 《Skull base》2007,17(5):317-324
The authors present a case of amyloid infiltration involving the trigeminal nerve that mimicked a malignant cavernous sinus tumor with perineural tumor infiltration. A 64-year-old man presented with trigeminal nerve numbness. Imaging revealed a plaque-like enhancing lesion along the right lateral cavernous sinus extending anteriorly into Meckel's cave and involving the proximal V2 and V3 branches of the trigeminal nerve. The patient underwent an extradural frontotemporal craniotomy with middle fossa exposure of the cavernous sinus to diagnose and treat the presumed malignant cavernous sinus tumor. A reddish mass involving the lateral dural wall of the cavernous sinus was resected. The gasserian ganglion, V2, and V3, the latter of which was biopsied, were enlarged. Permanent histopathological studies showed microscopic eosinophilic, amorphous material, which stained positive for Congo red, and an absence of neoplastic cells. The final diagnosis was amyloidoma. Thus, amyloidomas can involve the trigeminal nerve or ganglia and should be considered in the differential diagnosis of a cavernous sinus lesion mimicking a tumor. Patients may have symptomatic improvement of trigeminal neuropathy with resection of the amyloidoma outside the nerve capsule that is compressing the nerve, while resection of the lesion from within the capsule may result in permanent trigeminal nerve dysfunction. 相似文献
2.
Oren S Cohen Eli Vakil David Tanne Zeev Nitsan Roseline Schwartz Sharon Hassin-Baer 《Cognitive and behavioral neurology》2007,20(1):68-72
OBJECTIVES: To test a possible association between the educational level (EL), cognitive performance, and neuropsychiatric features in Parkinson disease (PD). BACKGROUND: An inverse association has been reported between EL and cognitive dysfunction in patients with senile dementia of Alzheimer type but it is yet unsettled whether education has a similar effect on cognition in PD. METHODS: Seventy-two PD patients (45 males, mean age 68.7+/-11.6 y) underwent a detailed neurologic examination, a battery of neuropsychologic tests, and questionnaires for the evaluation of psychosis, sleep disturbances, and depression. According to the number of educational years, patients were divided into 3 groups: low EL (0 to 8 y), (15 patients), intermediate EL (9 to 12 y) (28 patients), and high EL (>/=13 y) (29 patients). RESULTS: Patients with a higher EL had a better cognitive function and an association was found between the patients' EL and their scores in various neuropsychologic tests mainly those sensitive to frontal lobe dysfunction. Low education was associated with an increased risk for hallucinations and a trend for more depression, delusions, and sleep disturbances. CONCLUSIONS: The association between high educational attainment and the lower risk of cognitive dysfunction suggest that education might modulate cognitive performance in PD. 相似文献
3.
Ullmann Yehuda MD Shoshani Oren MD Fodor Adriana MD Ramon Yitzhak MD Carmi Nurit PhD Eldor Liron MD Gilhar Amos MD 《Dermatologic surgery》2005,31(10):1304-1307
BACKGROUND: The use of suctioned fat grafts for correction of soft tissue defects is a widespread procedure in esthetic and reconstructive surgery. The main disadvantage of this simple and sensible procedure is the unpredictable absorption rate of the fat graft. A lot of research has been performed aiming for enhancement of the take of the fat grafts. OBJECTIVE: Our study was performed to find if there is any favorable donor site for fat harvesting. METHODS: This in vivo experiment using the nude mice model enables the study of the long-term survival of human fat in an animal model. The fat was harvested from three donor areas: the thigh, abdomen, and breast of a 48-year-old woman who came for an elective esthetic procedure. After centrifugation, 1 cc of fat was injected subcutaneously into the scalp of the nude mouse. There were 15 mice in each of the three groups, according to the selected donor sites. The animals were sacrificed 16 weeks after the procedure. The extracted fat was evaluated in terms of weight, volume, and six histologic parameters: integrity, vascularization, cyst formation, fibrosis, necrosis, and inflammation. RESULTS: This study could not find any statistically significant differences between the three investigated donor sites in the evaluated parameters. CONCLUSION: On the basis of this study, there is no favorable area for harvesting fat grafts. The donor site can be chosen according to the preference of the surgeon and the patient. 相似文献
4.
5.
Fine needle aspiration biopsy was performed in two case of infiltrating skull lesions. The role played by this relatively simple procedure in avoiding a major operation is discussed. 相似文献
6.
7.
Despite awareness that depression may affect performance on commonly used neuropsychological tests, little research has been conducted on the relative impact of severity and type of depression on higher problem-solving ability. Major depressives (n = 13), dysthymics (n = 17), and non-psychiatric comparison subjects (n = 18) were administered the Wisconsin Card Sorting Test (WCST). Although diagnostic category was related only marginally to some WCST measures after controlling for intellectual function, depressive symptom severity emerged as an independent predictor of Total Errors, Perseverative Responses, and Failure to Maintain Set. These findings lend support to the suggestion that neuropsychological test batteries should include assessment for depression and suggest that even relatively mild depression may affect WCST scores. 相似文献
8.
Jennifer A. Ruskey Lior Greenbaum Léanne Roncière Armaghan Alam Dan Spiegelman Christopher Liong Oren A. Levy Cheryl Waters Stanley Fahn Karen S. Marder Wendy Chung Gilad Yahalom Simon Israeli-Korn Vered Livneh Tsvia Fay-Karmon Roy N. Alcalay Sharon Hassin-Baer Ziv Gan-Or 《European journal of medical genetics》2019,62(1):65-69
Background
Variants in GBA are the most common genetic risk factor for Parkinson's disease (PD), and are especially prevalent in the Ashkenazi Jewish (AJ) population. However, most studies on GBA in AJ genotype only seven selected Gaucher-associated pathogenic variants rather than sequencing the whole gene, which may leave carriers of PD-associated GBA variants undiscovered.Methods
GBA was fully sequenced using molecular inversion probes (MIPs) and Sanger sequencing in 735 AJ PD patients and 662 AJ controls, from Israel and New York. Additional AJ control data (n?=?3044) from the Inflammatory Bowel Disease Exome Portal was used.Results
Full GBA sequencing increased the number of variants discovered by 17.4%, compared to targeted genotyping. An additional 17 PD patients were identified with GBA-associated PD. The p.E326K variant was found in 1.6% of AJ PD patients, making it the second most common PD-associated GBA variant in AJ. GBA variants were found in 18% of PD patients and 7.5% of controls (OR?=?2.7, 95%CI?=?1.9–3.8, p?<?0.0001).Conclusion
Without full sequencing of GBA, or at minimum including p.E326K in the genotyping panel, a significant proportion of variant carriers go undiscovered and may be incorrectly assigned as non-carriers in studies or clinical trials. 相似文献9.
Cellular localization of complement C3 and C4 transcripts in intestinal specimens from patients with Crohn's disease
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Laufer J Oren R Goldberg I Horwitz A Kopolovic J Chowers Y Passwell JH 《Clinical and experimental immunology》2000,120(1):30-37
It has been suggested that the increase in C3 and C4 levels in jejunal perfusates of patients with Crohn's disease (CD) results from local intestinal synthesis of complement. The present study evaluated the expression of these complement genes in inflamed tissues from patients with CD. Surgically resected specimens from patients with CD and control tissue obtained from subjects with adenocarcinoma of the colon were evaluated for C3 and C4 gene expression by the use of 35S-labelled anti-sense RNA probes. All tissue samples, diseased and normal tissue, expressed C4 mRNA throughout in the intestinal epithelium. C3 mRNA was not detected in epithelial cells in histologically normal tissue, but in diseased specimens there was a focal distribution of C3 mRNA in epithelial cells of the crypts, but not in villous epithelium. Focal C3 gene expression correlated with crypt abscess formation and the presence of polymorphonuclear leucocytes in the lumen of the crypts. In addition, C3 mRNA was also found in macrophages of the submucosa. These macrophages were CD68+, fusiform with faint cytoplasm and morphologically different from the large rounded lamina propria macrophages, which do not express C3 mRNA. Multinucleated giant cells did not express either C3 or C4 genes. In addition to its presence in intestinal epithelium, C4 mRNA was also expressed in mast cells, which however did not express C3 mRNA. These observations identify cells in the intestinal wall expressing complement genes and support the hypothesis that there is local regulated production of complement in the intestine of patients with CD, and subsequent complement activation may contribute to the inflammatory process. 相似文献
10.
Cellular dysfunction in the diabetic fibroblast: impairment in migration,vascular endothelial growth factor production,and response to hypoxia 总被引:15,自引:0,他引:15
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lerman OZ Galiano RD Armour M Levine JP Gurtner GC 《The American journal of pathology》2003,163(1):303-312
Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O(2)), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 +/- 1.3 pg/ml versus 34.8 +/- 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients. 相似文献