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   6358篇
  免费   330篇
  国内免费   27篇
耳鼻咽喉   70篇
儿科学   98篇
妇产科学   72篇
基础医学   934篇
口腔科学   190篇
临床医学   375篇
内科学   1477篇
皮肤病学   61篇
神经病学   455篇
特种医学   313篇
外科学   748篇
综合类   36篇
预防医学   220篇
眼科学   260篇
药学   579篇
中国医学   13篇
肿瘤学   814篇
  2023年   18篇
  2022年   57篇
  2021年   96篇
  2020年   36篇
  2019年   47篇
  2018年   63篇
  2017年   53篇
  2016年   75篇
  2015年   85篇
  2014年   129篇
  2013年   169篇
  2012年   247篇
  2011年   272篇
  2010年   163篇
  2009年   141篇
  2008年   276篇
  2007年   300篇
  2006年   304篇
  2005年   288篇
  2004年   323篇
  2003年   305篇
  2002年   324篇
  2001年   258篇
  2000年   276篇
  1999年   249篇
  1998年   112篇
  1997年   93篇
  1996年   84篇
  1995年   70篇
  1994年   66篇
  1993年   68篇
  1992年   152篇
  1991年   190篇
  1990年   181篇
  1989年   168篇
  1988年   157篇
  1987年   137篇
  1986年   132篇
  1985年   95篇
  1984年   77篇
  1983年   51篇
  1982年   37篇
  1981年   29篇
  1980年   16篇
  1979年   49篇
  1978年   43篇
  1977年   34篇
  1976年   26篇
  1975年   14篇
  1966年   9篇
排序方式: 共有6715条查询结果,搜索用时 0 毫秒
91.
OBJECTIVE: This article aims to summarize the available data on reducing radiation dose exposure in routine chest CT protocols. First, the general aspects of radiation dose in CT and radiation risk are discussed, followed by the effect of changing parameters on image quality. Finally, the results of previous radiation dose reduction studies are reviewed, and important information contributing to radiation dose reduction will be shared. CONCLUSION: A variety of methods and techniques for radiation dose reduction should be used to ensure that radiation exposure is kept as low as is reasonably achievable.  相似文献   
92.
OBJECTIVES: Lower urinary tract symptoms (LUTS) are reported to influence the quality of life (QoL) of the elderly. The aim of this study was to elucidate the relationships among filling problems, voiding problems and QoL in elderly men and women. METHODS: A total of 450 males and 228 females, aged 50 years or older responded to a questionnaire, which included seven questions from the International Prostate Symptom Score (I-PSS) and 16 questions from the King's Health Questionnaire (KHQ). The relations among the filling, voiding subscores deliverable from I-PSS, and KHQ-QoL were investigated. RESULTS: The voiding subscore significantly correlated with the filling subscore with a considerably large standard deviation, and the filling subscore also significantly correlated with I-PSS in both genders. KHQ-QoL was significantly associated with the filling and voiding subscores in almost all domains of the KHQ. Multiple regression analyses demonstrated the filling, voiding subscores, and I-PSS explained the 55% or greater reduction in the QoL in six, four, six domains in men and four, three, four domains in women, respectively. CONCLUSIONS: The filling problems are slightly more associated with KHQ-QoL than voiding problems but filling problems did not appear to predominantly affect QoL as expected in both genders. We believe it valid to use I-PSS to evaluate voiding problems as well as filling problems in the elderly women.  相似文献   
93.
Abstract:  Peritubular capillaritis (PTCitis) has been recognized as one form of acute/active allograft rejection, and its relation to humoral immunity has been suggested. However, its mechanisms remain to be fully clarified, and there are no criteria for evaluating the extent of PTCitis in a biopsied allograft. In this study, we first evaluated the extent of PTCitis in early allografts in patients presenting with acute cellular rejection (ACR) and antibody-mediated rejection (AbAR). We also included patients who showed no evidence of ACR and/or AbAR. Next, we investigated whether or not PTCitis persisted and if peritubular capillary basement membrane (PTCBM) thickening was present in their follow-up biopsy specimens. We adopted the scoring system of PTCitis, which was presented at the Seventh Banff Conference on Allograft Pathology in 2003. In total, 53 patients were included in this study. At first biopsy, 17 showed ACR, eight showed AbAR, 16 showed mild PTCitis only, and 14 were without significant pathologic changes. The PTC score was the highest in the AbAR group, and in some patients the score gradually increased during the follow-up period. Similar changes were also observed in the group with mild PTCitis only. In late allografts, half of the patients with AbAR developed chronic rejection (CR), and the PTCBM score was the highest in that group. Surprisingly, CR was present in more than 30% of patients without ACR and/or AbAR but mild PTCitis only. In the control group, only a few showed CR and/or chronic allograft nephropathy (CAN). In conclusion, it became clear that we should carefully monitor for mild PTCitis in early allografts. In addition, our data also proved the usefulness of the PTC score and PTCBM score.  相似文献   
94.
We report a case of bladder hernia. A 68-year-old man was admitted to our hospital for the management of prostate cancer. An egg-sized soft mass was palpated at his right inguinal region. Magnetic resonance imaging and cystography revealed that the mass was a bladder hernia. During radical prostatectomy, we had to resect the bladder hernia for safe regional lymphadenectomy. This hernia was the extraperitoneal type. The stage of prostate cancer was pT3b N0 M0. This is the third reported case of inguinal bladder hernia associated with prostate cancer in Japan.  相似文献   
95.
Diseases associated with persistent urachus are relatively rare. During the past 9-year period, there have been 14 patients with urachal disease consisting of 10 with urachal abscess and 4 with urachal cancer. The 10 patients with urachal abscess consisted of 7 males and 3 females aged 19-77 years (mean, 46 years). The 4 patients with urachal cancer consisted of 2 males and 2 females aged 48-81 years (mean, 57 years). As symptoms, lower abdominal pain was frequently observed in the patients with persistent urachus with abscess and gross hematuria in those with urachal cancer. Echo and magnetic resonance imaging (MRI) were useful for visualizing the lesion. Computed tomogtaphic (CT) scanning could not visualize the lesion in 2 patients. Nine patients underwent MRI, which visualized the lesion in all of them. As urachal abscess, an umbilical fistula was observed in 3 patients, urachal cyst in 4, and urachal diverticulum in 1. The preoperative diagnosis was urachal cancer in 6 patients, and pathological examination showed 4 patients with adenocarcinoma, 1 with inflammatory granuloma, and 1 with pseudosarcoma. Urachal abscess was treated by resection of the abscess in 6 patients, transurethral resection in 1, and resection of the umbilicus and urachus and total cystectomy in the other. Of the patients with urachal cancer, 1 underwent total cystectomy and the other 3 underwent total urachal resection and partial cystectomy. In 2 patients with persistent urachus with abscess, the differentiation between abscess and malignant tumor was difficult.  相似文献   
96.
We report a case of idiopathic omental bleeding in a 27-year-old man who was brought to our hospital after the sudden development of intermittent abdominal pain, nausea, and fainting. Computed tomography showed intra-abdominal fluid and emergency laparotomy revealed a hemorrhagic mass in the omental bursa, which was excised. The patient was successfully treated and a diagnosis of idiopathic omental bleeding was made.  相似文献   
97.
OBJECTIVE: 76 patients who underwent laminoplasty for cervical spondylotic myelopathy were investigated regarding the impact of preoperative and postoperative degenerative spondylolisthesis on their neurologic outcome. METHODS: Radiographs were obtained 1 year postoperatively to investigate range of motion (ROM), lordotic curvature, and postoperative spondylolisthesis. RESULTS: By 1 year after surgery, 85% of those spondylolistheses present preoperatively had either resolved or improved on neutral lateral radiographs. The cross-sectional area of the spinal cord at the site of spondylolisthesis was measured using preoperative computed tomography myelography. Clinical results were evaluated by the recovery rate using Japanese Orthopaedic Association score. Patients with posterior spondylolisthesis showed a significantly poorer postoperative recovery rate. Intervertebral ROM in patients with preoperative spondylolisthesis was reduced, whereas cervical alignment had not deteriorated after laminoplasty. The group with posterior spondylolisthesis showed a significant reduction in the cross-sectional area of the spinal cord at the site of spondylolisthesis. Postoperative spondylolisthesis appeared in 15 patients, 10 of whom had preoperative spondylolisthesis at an adjacent site. CONCLUSION: The cause of poorer surgical results of those patients with preoperative posterior spondylolisthesis appears to be related to a higher degree of spinal cord compression than with preoperative anterior spondylolisthesis.  相似文献   
98.
Abstract: A 47-year-old Japanese man suffering from T-cell leukemia was examined for multiple subcutaneous abscesses followed to abrasion wound on his right knee. The causative organism was clustered, fine-branched filaments in pus aspirated from the lesions, identified as Nocardia brasiliensis. Most of the lesions regressed from the combined therapy of sulfamethoxazole and trimethoprim, leaving an ulcer on the patient's left leg. The nocardiosis cases in Japan until 1984, including this one, were briefly surveyed.  相似文献   
99.
Neurinoma grows in the modulated nerve with Schwann cells, and is observed for all positions of the body. It is comparatively rare for neurinoma to grow in the nasal cavity and paranasal sinuses, however. We report a case of neurinoma of the nasal septum. A 24-year-old man seen for nasal obstruction was found in anterior rhinoscopy to have a tumor of the bilateral nasal cavity. Computed tomography (CT) showed a soft tissue density mass in the anterior part of the nasal cavity. Because we suspected neurinoma from biopsy, we resected the tumor by Denker's operation under general anesthesia. We found that it originated from the nasal septum. Histopathological findings of the tumor indicated an Antoni A type neurinoma. After surgery, cartilago costalis was transplanted the plastic surgery to correct the defect in the nasal septum. The post operative course was good and no signs of recurrence were seen. This is the 19th case found in the literature.  相似文献   
100.

Background

Approximately 50% of patients with Fisher's syndrome show involvement of the pupillomotor fibers and present with mydriasis and light-near dissociation. However, it is uncertain whether this phenomenon is induced by an aberrant reinnervation mechanism as in tonic pupil, or is based on other mechanisms such as those associated with tectal pupils.

Cases

We evaluated the clinical course and the pupillary responses in four of 27 patients with Fisher's syndrome who presented with bilateral mydriasis.

Observations

The pupils of both eyes of the four patients were involved at the early stage of Fisher's syndrome. The pupils in patients 1 and 2 showed mydriasis with apparent light-near dissociation lasting for a significant period and had denervation supersensitivity to cholinergic agents. On the other hand, the pupils of patients 3 and 4 were dilated and fixed to both light and near stimuli.

Conclusions

Our observations indicate that the denervated iris sphincter muscles, which are supersensitive to the cholinergic transmitter, may play an important role in the expression of light-near dissociation in Fisher's syndrome.?Jpn J Ophthalmol 2007;51:224–227 © Japanese Ophthalmological Society 2007
  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