首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1468篇
  免费   72篇
  国内免费   11篇
耳鼻咽喉   5篇
儿科学   19篇
妇产科学   12篇
基础医学   123篇
口腔科学   9篇
临床医学   74篇
内科学   381篇
皮肤病学   17篇
神经病学   39篇
特种医学   93篇
外科学   411篇
综合类   3篇
预防医学   31篇
眼科学   31篇
药学   131篇
中国医学   8篇
肿瘤学   164篇
  2023年   20篇
  2022年   14篇
  2021年   38篇
  2020年   17篇
  2019年   25篇
  2018年   28篇
  2017年   33篇
  2016年   26篇
  2015年   35篇
  2014年   57篇
  2013年   62篇
  2012年   69篇
  2011年   70篇
  2010年   44篇
  2009年   38篇
  2008年   98篇
  2007年   96篇
  2006年   104篇
  2005年   84篇
  2004年   77篇
  2003年   66篇
  2002年   64篇
  2001年   40篇
  2000年   31篇
  1999年   39篇
  1998年   20篇
  1997年   17篇
  1996年   18篇
  1995年   15篇
  1994年   8篇
  1993年   6篇
  1992年   17篇
  1991年   23篇
  1990年   25篇
  1989年   14篇
  1988年   19篇
  1987年   11篇
  1986年   8篇
  1985年   15篇
  1984年   8篇
  1983年   5篇
  1979年   9篇
  1977年   3篇
  1974年   3篇
  1972年   3篇
  1971年   4篇
  1970年   3篇
  1969年   2篇
  1967年   3篇
  1966年   5篇
排序方式: 共有1551条查询结果,搜索用时 15 毫秒
81.

Objective

Behaviors associated with frontal/executive impairments are common in patients with schizophrenia. Our aim was to reconfirm that morphological brain abnormalities in schizophrenia patients would overlap the areas underpinning frontal systems behavior, and examine whether any specific association exists between abnormalities of brain structures and frontal behavioral deficits in schizophrenia patients.

Method

Twenty-six schizophrenia patients and 26 matched healthy controls underwent structural magnetic resonance imaging and their frontal function was assessed by a self-rating questionnaire, Frontal Systems Behavior Scale (FrSBe). We applied voxel-based morphometry (VBM) to investigate regional brain volume alternations.

Result

Compared with healthy controls, schizophrenia patients showed reduced gray matter volume in multiple frontal and temporal structures, namely, the bilateral dorsolateral prefrontal cortices (DLPFC), bilateral medial prefrontal cortices, left ventrolateral prefrontal cortex, bilateral anterior cingulate cortices, and bilateral superior temporal gyri. The scores on the executive dysfunction subscale of the FrSBe were correlated with volume reduction in the bilateral DLPFC in the patient group.

Conclusion

Our result suggests that pathology of the DLPFC could be the neural basis of real-life dysexecutive behaviors in schizophrenia patients.  相似文献   
82.
83.
84.
Secondary hyperparathyroidism (II HPT) is a major complication in chronic dialysis patients, and percutaneous ethanol injection therapy (PEIT) has become a useful alternative treatment for II HPT. However, the existence of ectopic parathyroid glands is a major problem when conducting PEIT. Ectopic parathyroid gland accepts 10-35% of II HPT, and the missing glands cannot be detected consistently by any imaging techniques, including scintigraphy. Intrathyroid parathyroid gland is as rare as about 1% and recurrence of missing glands after parathyroidectomy (PTx) has been reported in some cases. We report here a 52-year-old female in whom an ectopic parathyroid gland was defected successfully and intact-PTH controlled by tentative PEIT. At the first examination, a left parathyroid adenoma and a right thyroid goiter were pointed out by ultrasonography, CT and scintigraphy. PEIT was applied twice to the left parathyroid adenoma, but intact-PTH was not decreased. Ultrasonography, CT, 201Tl-99mTc subtraction scintigraphy and fine needle aspiration biopsy (FNAB) were performed again to search for the existence of ectopic glands. The results suggested that the right intrathyroid tumor was an ectopic parathyroid gland. Consequently, tentative PEIT was applied to the right intrathyroid tumor, and successful control of intact-PTH and serum Ca was eventually achieved. To our knowledge, this is the first reported case of secondary hyperparathyroidism with an ectopic intrathyroid gland that was successfully controlled by PEIT. In this case, it was suggested that tentative PEIT of intrathyroid tumor was a useful method for detecting an ectopic parathyroid gland.  相似文献   
85.
We report a case of nephrostomy tract tumor seeding following percutaneous pyeloscopic manipulation of a renal pelvic carcinoma. To our knowledge, this is the second reported case of such a lesion surrounding the nephrostomy tract. Percutaneous pyeloscopic treatment carries a potential risk of local tumor spillage and implantation in the nephrostomy tract.  相似文献   
86.
The MM50 is a racetrack microtron that can emit photon beams or electron beams up to 50 MeV. The MM22 using the scanning beam method and the MM22 using a flattening filter method both to flatten the emission field and a water phantom with particular function measurable of PDD etc. in an accelerator using the scanning beam method to make up the PDD curve of photon beams from the linear accelerator. The Clinac21EX was thus employed. The maximum depth of beam flux was shallow, the gradient of the flux decrement large, the surface dose large, and the estimated nominal energy low to the same nominal energy. From these findings, it can be said that thorough comprehension of the characteristics of beam flux properties for these units is necessary when photon beams are to be used.  相似文献   
87.
To examine the possibility of diagnosing Alzheimer-type dementia, we studied this condition using the run length matrix, on head MR images of 29 Alzheimer-type dementia patients (8 men, 21 women, 78.7 +/- 6.7 years) and healthy elderly controls (10 men, 19 women, 72.3 +/- 8.7 years) . The results showed that differences in GLN (gray level nonuniformity) and RLN (run length nonuniformity) were statistically significant. Furthermore, discriminant analysis based on GLN and RLN showed a rate of sensitivity of 69.0%, specificity 86.2%, and correct classification 77.6%. Although this rate of correct classification is inferior to the planimetric and volumetric methods, run length matrix is only one method of texture analysis. The results of this study indicate the possibility of MR imaging-based diagnosis of Alzheimer-type dementia with texture analysis including a run length matrix.  相似文献   
88.
We describe a 47-year-old woman with a 13-year history of asymptomatic midline submental swelling. Cytologic examination of a fine-needle aspiration specimen from the solid mass revealed adenocarcinoma. The preoperative diagnosis was thyroglossal duct carcinoma. A Sistrunk procedure was performed and microscopic examination revealed papillary adenocarcinoma. The postoperative course was uneventful and there were no signs of local recurrence or metastasis at one year after surgery.   相似文献   
89.
Recently, the pars plana route of injection has been used to administer drugs for the treatment of severe intraocular infections. We observed a complication of this method in a patient with AIDS and cytomegalovirus (CMV) retinopathy. Offprint requests to: A. Kreiger  相似文献   
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号