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   2486篇
  免费   89篇
  国内免费   12篇
耳鼻咽喉   37篇
儿科学   39篇
妇产科学   37篇
基础医学   250篇
口腔科学   25篇
临床医学   122篇
内科学   697篇
皮肤病学   47篇
神经病学   184篇
特种医学   120篇
外科学   538篇
综合类   11篇
预防医学   56篇
眼科学   45篇
药学   143篇
中国医学   10篇
肿瘤学   226篇
  2023年   21篇
  2022年   42篇
  2021年   64篇
  2020年   24篇
  2019年   49篇
  2018年   46篇
  2017年   50篇
  2016年   41篇
  2015年   41篇
  2014年   55篇
  2013年   80篇
  2012年   129篇
  2011年   157篇
  2010年   87篇
  2009年   53篇
  2008年   137篇
  2007年   148篇
  2006年   126篇
  2005年   113篇
  2004年   116篇
  2003年   104篇
  2002年   120篇
  2001年   64篇
  2000年   68篇
  1999年   63篇
  1998年   31篇
  1997年   19篇
  1996年   24篇
  1995年   23篇
  1994年   15篇
  1993年   23篇
  1992年   43篇
  1991年   42篇
  1990年   43篇
  1989年   41篇
  1988年   33篇
  1987年   32篇
  1986年   32篇
  1985年   22篇
  1984年   19篇
  1983年   16篇
  1979年   25篇
  1978年   9篇
  1977年   8篇
  1976年   9篇
  1974年   10篇
  1972年   8篇
  1971年   8篇
  1969年   8篇
  1968年   12篇
排序方式: 共有2587条查询结果,搜索用时 15 毫秒
41.
42.
A 22-year-old female was diagnosed as having acute lymphoid leukemia (ALL) in February 1995, from the findings of peroxidase negative, CD10+, CD19+, TdT+ and rearrangement of IgH and TCR beta. AdVP (doxorubicin, vincristine and prednisolone) therapy achieved a complete remission (CR). Bone marrow transplantation had to be abandoned because of the lack of an HLA-identical donor. Intensification therapy was thus carried out repeatedly. In June 1998, myeloblast with Auer rods, peroxidase positive, CD13+, CD33+ and HLA-DR+, appeared. The patient was diagnosed as having lineage switch acute myeloid leukemia (AML) from ALL. Though A-DMP (cytosine arabinoside, daunorubicin, 6-mercaptopurine) therapy was resistant, AdVP therapy led to a CR. The patient died of cardiotoxicity from anthracyclines in February 1999. From the results of the Ramasamy method using the clonal rearrangements of the Ig heavy chain gene locus, the origin of the pathological cells of ALL and AML was indicated to be the same leukemia clone.  相似文献   
43.
[Purpose] The purpose of this study was to make an experimental model of cervical spinal cord injury (CSCI) using Wistar rats, in order to analyze the influence of CSCI on the respiratory function. [Subjects] Thirty-two male 12-week-old Wistar rats were used. [Methods] The CSCI was made at the levels from C3 to C7, and we performed pneumotachography and electromyography (EMG) on the diaphragm. Computed tomography was used to determine the level of spinal cord damage. [Results] After the operation, the tidal volume of the rats with a C3 level injury decreased to approximately 22.3% of its pre-injury value. In addition, in the same rats, the diaphragmatic electromyogram activity decreased remarkably. Compared with before CSCI, the tidal volume decreased to 78.6% of its pre-injury value in CSCI at the C5 level, and it decreased to 94.1% of its pre-injury value in CSCI at the C7 level. [Conclusion] In the rats that sustained a CSCI in this study, the group of respiratory muscles that receive innervation from the thoracic spinal cord was paralyzed. Therefore, the EMG signal of the diaphragm increased. These results demonstrate that there is a relationship between respiratory function and the level of CSCI.Key words: Cervical spinal cord injury, Respiratory function, Electromyography of diaphragm muscle  相似文献   
44.
45.
46.
A thickened, enhanced cyst wall on imaging examinations is one of the “worrisome features” described in the consensus guidelines for management of intraductal papillary mucinous neoplasm of the pancreas (IPMN). Podoplanin (PDPN) expression by cancer-associated fibroblasts is known to be an indicator of poor prognosis in some types of cancer. We performed immunohistochemical staining for alpha-smooth muscle actin (α-SMA) in IPMN lesions and determined the pathological wall thickness by measuring the thinnest and thickest α-SMA-positive parts of the wall of the largest cyst in each case, and the mean of these two values was recorded as the wall thickness. The thickness of the pathological wall increased with progression from IPMN with low-grade dysplasia to IPMN with an invasive carcinoma. The pathological wall was thicker in IPMN with main duct involvement, nongastric-type IPMN, and IPMN with mural nodules. We also stained for PDPN and assessed the thickness of cyst wall staining as for α-SMA. The thickness of the PDPN-positive cyst wall varied in a pattern similar to the thickness of the α-SMA-positive pathological cyst wall. PDPN-positive stromal fibroblasts in the invasive component of IPMN-IC were evaluated as a ratio to α-SMA-positive fibroblasts. A high ratio (>50 %) of PDPN-positive stromal fibroblasts was a predictor of poor outcome. PDPN expression in the cyst wall correlates with the progression of IPMN. PDPN may be a significant prognostic marker of IPMN-IC.  相似文献   
47.
48.
PatientA 66-year-old woman, who had a bilateral free-end edentulous mandible and no experience with dentures, was examined for the chief complaint of masticatory dysfunction on left side of dental arch. A unilateral distal extension removable partial denture (RPD) replacing lower-left molars was selected. Tomographic images were obtained using Fluorine-18 NaF positron emission computerized tomography (NaF-PET)/computed tomography (CT) before the RPD use and at 1, 6, and 13 weeks after the RPD use to observe the metabolic changes in residual bone caused by the RPD use. PET standardized uptake values (SUVs) and CT values were calculated for lower-left edentulous site (test side) and lower-right edentulous site (control side). As a result, SUVs on the control side remained static after the RPD use, whereas those on the test side increased at 1 and 6 weeks after the RPD use and then decreased. However, CT images showed no obvious changes in the bone shape and structure beneath RPD, and CT values both on the control and test sides did not change either.DiscussionThis report shows that NaF-PET could detect bone metabolic changes soon after the RPD use, which cannot be detected by clinical X-rays. The SUV changes may be a mechanobiological reaction to the pressure due to the RPD use, and wearing of the RPD may increase the bone turnover beneath denture.ConclusionThis report demonstrates that wearing of an RPD increases bone turnover beneath denture immediately after the RPD use without clinically detectable changes in bone structure or volume.  相似文献   
49.
In some anti-ganglioside antibody-mediated neuropathies, human and experimental data suggest a common pathogenic mechanism of dysfunction/disruption at the node of Ranvier resulting in a pathophysiologic continuum from transitory nerve conduction failure to axonal degeneration. The traditional classification of polyneuropathies into demyelinating or axonal may generate some confusion in the electrophysiological diagnosis of Guillain–Barré syndrome subtypes associated with anti-ganglioside antibodies. The axonal forms show, besides axonal degeneration, promptly reversible nerve conduction failure. This may be interpreted, by a single electrophysiological study, as demyelinating conduction block or distal axonal degeneration leading to errors in classification and in establishing prognosis. Moreover the term axonal may be misleading as it is commonly associated to axonal degeneration and not to a transitory, promptly reversible, dysfunction of the excitable axolemma. To focus on the site of nerve injury and overcome the classification difficulties, we propose the new category of nodo-paranodopathy which seems appropriate to various acute and chronic neuropathies associated with anti-ganglioside antibodies and we think better systematizes the neuropathies characterized by an autoimmune attack targeting the nodal region.  相似文献   
50.
The large Japanese wood mouse (Apodemus speciosus) is common, but endemic to Japan, and its population structure was affected by habitat fragmentation because of urbanization. It suggested that the species might be one of the important models for the conservation of ecosystems and biodiversity affected by humans, including the effect of radioactive discharge caused by nuclear power plant accidents at Fukushima. We developed and characterized 25 novel polymorphic microsatellite markers from the next-generation sequencing data in an effort to provide an effective tool for genetic studies on this species. In 8 individuals from Aomori, Japan, the number of alleles and expected heterozygosities ranged from 5 to 13 and from 0.795 to 0.991, respectively, suggesting the availability of these markers for genetic studies in this species.  相似文献   
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