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   15014篇
  免费   674篇
  国内免费   128篇
耳鼻咽喉   129篇
儿科学   337篇
妇产科学   184篇
基础医学   1717篇
口腔科学   240篇
临床医学   794篇
内科学   3894篇
皮肤病学   480篇
神经病学   1121篇
特种医学   925篇
外科学   3080篇
综合类   70篇
一般理论   2篇
预防医学   329篇
眼科学   288篇
药学   685篇
中国医学   29篇
肿瘤学   1512篇
  2023年   82篇
  2022年   155篇
  2021年   312篇
  2020年   210篇
  2019年   221篇
  2018年   294篇
  2017年   264篇
  2016年   362篇
  2015年   362篇
  2014年   491篇
  2013年   585篇
  2012年   808篇
  2011年   915篇
  2010年   580篇
  2009年   511篇
  2008年   899篇
  2007年   941篇
  2006年   933篇
  2005年   934篇
  2004年   846篇
  2003年   828篇
  2002年   880篇
  2001年   224篇
  2000年   182篇
  1999年   227篇
  1998年   249篇
  1997年   194篇
  1996年   217篇
  1995年   178篇
  1994年   168篇
  1993年   135篇
  1992年   172篇
  1991年   149篇
  1990年   162篇
  1989年   145篇
  1988年   122篇
  1987年   98篇
  1986年   104篇
  1985年   86篇
  1984年   69篇
  1983年   46篇
  1982年   44篇
  1981年   45篇
  1980年   49篇
  1979年   42篇
  1978年   25篇
  1977年   32篇
  1976年   23篇
  1971年   30篇
  1969年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The concentrations of serum IgE (PRIST) and IgE- and IgG-specific antibodies to egg protein were determined in paired sera taken from students who had received influenza virus vaccine. Although persons who gave a history of allergy to egg or to chicken feathers were excluded, 10-16% of vaccinees possessed higher titres of serum IgE and IgE-specific antibody (RAST) to egg white (F1) allergen before vaccination. The titres of IgG-specific antibody to egg protein (ovalbumin and ovomucoid antigens) were negligible, and did not show any significant response after vaccination. In contrast, IgE-specific antibody to F1 allergen rose significantly in a considerable number of the vaccines. The results obtained indicate possible contamination of vaccine products with allergens of egg origin and a potential risk of allergic manifestation after influenza vaccination.  相似文献   
52.
A CASE OF METASTATIC YOLK SAC TUMOR OF TESTIS IN A CHILD   总被引:1,自引:0,他引:1  
We report a case of testicular yolk sac tumor in a child aged 3 years and 6 months with multiple bulky metastases to lung and retroperitoneum (stage 11182). After three courses of chemotherapy with a PV 8 regimen (cisplatin, vinblastine and bleomycin). complete and partial responses were obtained for lung and retroperitoneal lymph node metastases, respectively. The patient was followed-up closely. However, on the basis of a re-elevated alpha-letoprotein (AFP) after 4 months' follow-up, he was treated with three courses of salvage chemotherapy with a modified VAB-6 regimen (cyclophosphamide. etoposide. actinomycin D, bleomycin and cisplatin), lollowed by retroperitoneal lymph node dissection. Histologically, only necrotic tissue was found. There is no evidence of recurrence 24 months after lymphadenectomy. There is very little information in the literature on the appropriate management of postchemotherapy residual mass in pediatric testicular tumors.  相似文献   
53.
Primary leiomyosarcoma of the thyroid gland   总被引:1,自引:0,他引:1  
Primary leiomyosarcoma of the thyroid gland is extremely rare, and to the best of our knowledge only five well-documented cases have been reported in the world literature. We herein report a 58-year-old female patient with primary leiomyosarcoma of the thyroid who was successfully treated by total thyroidectomy with a modified neck dissection. Immunohistochemically, the tumor cells showed positive reactivity to α-smooth muscle actin and vimentin. Radical surgery was thus considered to be essential in the treatment of this rare but rather aggressive malignancy.  相似文献   
54.
Delayed manifestation of aortic stenosis caused by abdominal blunt trauma is rare. We report herein the case of a 67-year-old man who was taken to a nearby hospital after being crushed between a heavy truck and a wall. An emergency laparotomy was performed, revealing only a mesenteric tear which was repaired. He was discharged after an uneventful postoperative course; however, 1 month later he began to experience intermittent claudication, and presented to our hospital in December 1994, 1 year after the first operation. Angiography and enhanced computed tomography (CT) demonstrated infrarenal abdominal aortic dilatation with distal stenosis. Both the dilated and stenotic lesions were resected and bypass surgery was performed. Pathologic examination demonstrated that the intima had been lacerated circumferentially and everted distally, causing the aortic stenosis. To our knowledge, this is the first case of the delayed manifestation of traumatic aortic stenosis to be documented in Japan. The etiology of this rare complication of blunt trauma is described in this report.  相似文献   
55.
We describe herein a rare case of primary malignant melanoma of the rectum in an 85-year-old woman. The patient presented with intermittent rectal bleeding, and a colonoscopy revealed an ulcerated polypoid mass in the rectum, located 5 cm from the anal verge. The lesion was histologically characterized by solid growths of small round cells with scanty cytoplasm and prominent nucleoli. Although no melanin pigment was found in the tumor cells, they were immunohistochemically positive for HMB-45, a monoclonal antibody highly specific for malignant melanoma. Thus, HMB-45 proved very useful to establish a diagnosis of amelanotic malignant melanoma of the rectum.  相似文献   
56.
Abstract: Two autopsied female sibling cases of sudanophilic leukodystrophy are reported. Case A and case B were the second and third of seven siblings, and a sister and a brother died from severe progressive neurological disease with similar symptoms. Consanguineous marriages were noted in the family of both cases through the past three generations. Case A gradually developed intellectual deterioration and tetraplegia at the age of 29, progressed to akinetic mutism within one year and thereafter survived for 14 years. Neuropathologically, a severe atrophy and degeneration were noted in the white matter of the whole cerebrum, sparing the subcortical U-fibers. Myelin and axons were severely damaged with peripheral astrocytic gliosis. Case B developed similar clinical symptoms at the age of 20 and survived for 7 years in the state of akinetic mutism. Similar postmortem findings as those of case A were found in the white matter of the cerebrum with formation of sudanophilic breakdown products and with thick fibrillary gliosis. The pyramidal tract was completely degenerated. There was no accumulation of abnormal lipid in the brains of both cases.  相似文献   
57.
Background The purpose of this study was to examine the effects of bacterial suporantigens, which can derange the immune response and contribute to the renal lesions of immunoglobulin A (lgA) nephropathy. Methods Twenty-five micrograms of a bacterial superantigen, staphylococcal enterotoxin B (SEB), was injected into IgA nephropathy-prone ddY mice intrathymically when they reached 6 weeks of age. Evaluation included measurement of albumin excretion in urine, immunoglobulin concentration, and lymphokine production in vitro, as well as analysis of T-cell receptor expression in splenic T-cell subsets and examination of renal histology by light and fluorescence microscopy. Results At 40 weeks of age, the serum level of IgA in these mice was substantially increased and the number of Vβ8+ CD4+splenic T-cells was significantly decreased compared with measurements in untreated controls. Both control and SEB-treated mice excreted less than 30 μg/mL of urinary albumin. In mice given SEB, the amount of interleukin 2 (IL-2) and tumor necrosis factor-α (T helper 1 [Th1]-type cytokines) produced by the in vitro-stimulated lymphocytes significantly decreased. whereas that of interleukin 4 (IL-4) and interleukin 6 (IL-6) (Th2-type cytokines) markedly increased compared with measurements in control mice. At 40 weeks of age, mice given SEB showed marked glomerular hypercellularity and enhanced glomerular C3 deposition by renal histology, compared with control mice. Conclusion These results suggest that bacterial superantigen SEB may modify glomerular lesions through activating Th2 cells, while inducing deletion of Th1 cells in this experimental model.  相似文献   
58.
We report herein the case of a premature infant with esophageal atresia (EA) and a tracheoesophageal fistula (TEF) associated with cardiac anomalies who was successfully treated by an early ligation of the TEF following gastrostomy, and delayed repair of the esophagus. A 1212-g male was born prematurely at 31 gestational weeks, at which time he was diagnosed as having EA with TEF and patent ductus arteriosus (PDA), ventricular septal defect (VSD), and atrial septal defect (ASD). A gastrostomy was initially performed but following extubation he gradually became tachypneic. A chest roentogenogram revealed atelectasis and ground-glass appearance, and reintubation was required. Ligation of the TEF was performed 53h after his birth. Following the improvement of his respiratory condition through ventilatory support and the intratracheal administration of pulmonary surfactant, he underwent repair of the esophagus on the 6th day of life. Postoperatively, he suffered from heart failure, but was treated with peritoneal dialysis and pharmacological closure of the PDA. Weaning the infant from the ventilator proved difficult, but it was finally achieved when he had reached a weight of 2268g at 3 months of age by enteral feeding. Our experience of this case demonstrates that early ligation of TEF should be performed for a premature infant with EA and TEF before respiratory distress syndrome (RDS) has developed. If a gastrostomy is required to prevent gastric distention, it should be followed by simultaneous or immediate ligation of the TEF.  相似文献   
59.
Between January 1985 and September 1994, 21 patients with psychiatric disorders underwent various forms of surgery at our hospital. There were 12 men and 9 women with an average age of 57.6 years. The coexisting psychiatric disorders were schizophrenia in 15 patients, depression in 2, dementia in 2, mental retardation with epilepsy in 1, and Parkinson's disease in 1. All the patients had been receiving neuroleptic medications for a long period. The indications for surgery were: cholelithiasis in 6 patients, acute appendicitis in 4, perforation of the small intestine in 3, incarceration of an inguinal hernia in 2, and esophageal cancer, stomach cancer, bleeding from a gastric ulcer, perforation of a duodenal ulcer, strangulating ileus, and burns in 1 patient each, respectively. All of the patients who underwent elective surgery were given epidural anesthesia with or without general anesthesia. Antipsychotic medications were given until just prior to surgery and recommenced concurrent with the first meal. Abnormal behavior was observed in 11 patients (52.4%) postoperatively, but all the patients were discharged in accordance with recovery from their surgical disorder. Intra- and postoperative hypotension resistant to intravenous catecholamine administration was recognized in 9 patients (42.9%), and this peculiar complication should be borne in mind when patients with psychiatric disorders require surgical management. Presented at the 94th annual meeting of the Japanese Surgical Society, held in Tokyo in March, 1994  相似文献   
60.
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