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   377篇
  免费   0篇
电工技术   2篇
化学工业   9篇
金属工艺   1篇
机械仪表   3篇
建筑科学   1篇
轻工业   1篇
无线电   9篇
一般工业技术   16篇
冶金工业   324篇
原子能技术   1篇
自动化技术   10篇
  2019年   1篇
  2016年   1篇
  2014年   3篇
  2013年   4篇
  2012年   4篇
  2011年   1篇
  2010年   1篇
  2009年   1篇
  2008年   4篇
  2007年   1篇
  2006年   2篇
  2005年   3篇
  2004年   3篇
  2003年   1篇
  2002年   5篇
  1999年   17篇
  1998年   93篇
  1997年   48篇
  1996年   32篇
  1995年   22篇
  1994年   11篇
  1993年   25篇
  1992年   4篇
  1991年   5篇
  1990年   9篇
  1989年   8篇
  1988年   8篇
  1987年   6篇
  1986年   3篇
  1985年   6篇
  1984年   1篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   1篇
  1978年   2篇
  1977年   5篇
  1976年   20篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
  1966年   1篇
  1948年   1篇
  1946年   1篇
  1928年   1篇
  1926年   2篇
排序方式: 共有377条查询结果,搜索用时 15 毫秒
1.
On the basis of clinical signs and histological findings eight 9-month-old male rusa deer (Cervus timorensis) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5 degrees C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested polymerase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer.  相似文献   
2.
Since the advent of computed tomography (CT) traumatic intraventricular haemorrhage (IVH) has been diagnosed more often. It has reportedly been associated with a poor prognosis, but pure or solitary IVH is rare, suggesting that other lesions occurring concurrently with it may contribute to the poor outcome. In a series of 65 patients with severe head injury (GCS < or = 8), 14 (22%) had IVH on initial CT. Death rate in these 14 was 21%, not significantly different from that in patients without IVH (14%), although a significantly higher proportion of patients without IVH had a good outcome. These results suggest that mortality is related to other lesions associated with IVH rather than to IVH alone and that the presence of IVH does not necessarily lead to a poor outcome.  相似文献   
3.
Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment.  相似文献   
4.
5.
We consider some aspects of a data compression scheme called block truncation coding which are necessarily encountered when the scheme is implemented in practice. We derive an expression used to compute an essential quantity of the algorithm and analyze the effect of perturbing this quantity. Furthermore, we discuss how best to account for the perturbation in the overall scheme.  相似文献   
6.
Gaucher's disease is a lysosomal storage disease in which cells of the reticuloendothelial system accumulate the lipid glucocerebroside. It is characterized by slowly progressive visceral and osseous involvement. One of the latter manifestations includes lipid infiltration of bone marrow. We monitored the rate of inhaled 133Xe uptake and wash-out over diseased and normal metaphyseal and epiphyseal areas of the knee. Twenty-two patients (15 adults, 7 children) with various degrees of previously diagnosed Gaucher's disease were positioned supine under a gamma-camera interfaced to a computer system. All patients rebreathed 133Xe gas from a closed system for 10 min followed by 14 min of wash-out. Digitized images of the lung, liver, spleen, bony sites and soft tissue were obtained at 1 min intervals during the wash-in and wash-out phases. Counts for each ROI were normalized per 100 pixels and plotted as a function (time). Maximum uptake was also calculated by relating the counts/ROI/100 pixels to the 10 min integrated lung count during equilibrium (the administered "dose"). There was essentially no 133Xe uptake in liver and spleen involved with Gaucher's disease. Monophasic uptake and biphasic wash-out curves were observed in the limited investigative population. Skeletal Gaucher deposits released the 133Xe at a greater rate relative to soft tissue.  相似文献   
7.
8.
CONTEXT: Inpatient rehabilitation after elective hip and knee arthroplasty is often necessary for patients who cannot function at home soon after surgery, but how soon after surgery inpatient rehabilitation can be initiated has not been studied. OBJECTIVE: To test the hypothesis that high-risk patients undergoing elective hip and knee arthroplasty would incur less total cost and experience more rapid functional improvement if inpatient rehabilitation began on postoperative day 3 rather than day 7, without adverse consequences to the patients. DESIGN: Randomized controlled trial conducted from 1994 to 1996. SETTING: Tertiary care center. PARTICIPANTS: A total of 86 patients undergoing elective hip or knee arthroplasty and who met the following criteria for being high risk: 70 years of age or older and living alone, 70 years of age or older with 2 or more comorbid conditions, or any age with 3 or more comorbid conditions. Of the 86 patients, 71 completed the study. INTERVENTIONS: Random assignment to begin inpatient rehabilitation on postoperative day 3 vs postoperative day 7. MAIN OUTCOME MEASURES: Total length of stay and cost from orthopedic and rehabilitation hospital admissions, functional performance in hospitals using a subset of the functional independence measure, and 4-month follow-up assessment using the RAND 36-item health survey I and the functional status index. RESULTS: Patients who completed the study and began inpatient rehabilitation on postoperative day 3 exhibited shorter mean (+/-SD) total length of stay (11.7+/-2.3 days vs 14.5+/-1.9, P<.001), lower mean (+/-SD) total cost ($25891+/-$3648 vs $27762+/-$3626, P<.03), more rapid attainment of short-term functional milestones between days 6 and 10 (36.2+/-14.4 m ambulated vs 21.4+/-13.3 m, P<.001; 4.8+/-0.8 mean transfer functional independence measure score vs 4.3+/-0.7, P<.01), and equivalent functional outcome at 4-month follow-up. CONCLUSION: These data showed that high-risk individuals were able to tolerate early intensive rehabilitation, and this intervention yielded faster attainment of short-term functional milestones in fewer days using less total cost.  相似文献   
9.
Amiodarone is a benzofuran derivative with a chemical structure similar to thyroxine. Originally introduced to treat angina pectoris, amiodarone was found to have antiarrhythmic properties, and in 1985, was approved in the United States for treatment of life-threatening ventricular arrhythmias. It is now used for various ventricular and supraventricular arrhythmias refractory to conventional first-line medications, and as a result, side effects have been observed with increased frequency. The most severe and potentially life-threatening of these side effects is the development of pulmonary toxicity. Typically, amiodarone pulmonary toxicity (APT) is manifested by acute pneumonitis and chronic fibrosis. Amiodarone-associated hemoptysis (AAH) is a rare occurrence. The authors describe a case of AAH successfully treated with cessation of drug and steroid therapy.  相似文献   
10.
Marrow stromal layers were used to investigate the potential role of negative regulators produced by the marrow microenvironment as one potential cause of hematopoietic suppression after chemotherapy and cytokines. Stromal layers were established from marrow of normal or prechemotherapy donors and breast cancer patients after hematological recovery from one cycle of 5-fluorouracil, leucovorin, doxorubicin, and cyclophosphamide and GM-CSF or PIXY321 (GM-CSF/IL-3 fusion protein). Normal donor CD34+ cells were placed in contact with stromal layers, and the number of colony-forming units for granulocytes and macrophages (CFU-GM) was determined. There were 25-79% fewer CFU-GM in post-chemotherapy stromal layer cocultures than in no chemotherapy cocultures. With neutralizing antibody to TNF-alpha the number of CFU-GM in no chemotherapy and post-chemotherapy stromal cocultures was, respectively, 96 +/- 7% (n = 5) and 142 +/- 8% (n = 5) of the number with no antibody treatment. PIXY321 and GM-CSF pretreated stromal layers also suppressed production of CFU-GM. Anti-TNF-alpha promoted an increase in CFU-GM numbers from GM-CSF, but not PIXY321, pretreated stromal cocultures. The results demonstrate that post-chemotherapy marrow stromal layers were deficient in supporting in vitro hematopoiesis and suggest that negative regulators induced by chemotherapy and cytokines may be one cause for this defect.  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