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   209篇
  免费   3篇
儿科学   21篇
妇产科学   1篇
基础医学   12篇
口腔科学   3篇
临床医学   32篇
内科学   62篇
皮肤病学   6篇
神经病学   19篇
特种医学   1篇
外科学   29篇
综合类   1篇
预防医学   2篇
药学   10篇
肿瘤学   13篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2015年   2篇
  2014年   1篇
  2013年   1篇
  2012年   1篇
  2011年   3篇
  2010年   3篇
  2009年   7篇
  2007年   3篇
  2006年   9篇
  2005年   2篇
  2004年   4篇
  2003年   6篇
  2002年   3篇
  2001年   2篇
  1999年   4篇
  1998年   15篇
  1997年   29篇
  1996年   14篇
  1995年   8篇
  1994年   18篇
  1993年   6篇
  1992年   7篇
  1991年   9篇
  1990年   1篇
  1989年   4篇
  1988年   2篇
  1987年   3篇
  1985年   3篇
  1984年   4篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1977年   3篇
  1976年   1篇
  1975年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1958年   1篇
  1957年   5篇
  1956年   8篇
  1955年   4篇
  1954年   3篇
排序方式: 共有212条查询结果,搜索用时 0 毫秒
1.
Interferon (IFN) therapy is of proven efficacy in chronic hepatitis C, but it is not universally effective and is often limited by side effects. Cyclosporine A (CsA) is a potent immunosuppressant widely used in organ transplantation. We conducted a pilot study to determine whether CsA therapy could affect aminotransferase activity and hepatitis C virus RNA levels in patients with chronic hepatitis C. Cyclosporine A was administered to 10 patients (mean age of 59 years; male: female = 9:1) who did not respond to IFN therapy previously and who had elevated serum alanine aminotransferase (ALT) values for at least 6 months. All patients were positive for HCV-RNA by RT-PCR with genotype 1b. Their mean duration of hepatitis was 15 years. Oral CsA was given for 3 months in a dose that was increased at 1 month intervals from 1.5–2.0 to 2.0–3.0 and 3.0–4.0 mg/kg per day. All patients completed the treatment schedule, although two patients developed mild non-symptomatic hypertension. Serum ALT levels gradually decreased in all but one patient. The mean percentage decrease was 59.5% at the end of therapy (from 153 ± 82 to 62 ± 48 IU/L; P < 0.02). The ALT levels fell to the normal range in five patients, although once therapy was discontinued the enzyme levels tended to return to pretreatment levels. Serum aspartate aminotransferase and g-glutamyl transpeptidase levels similarly decreased. The serum HCV-RNA titre, determined by competitive RT-PCR, did not change in any patient throughout the study period. There were no appreciable alterations in other laboratory tests, such as serum creatinine levels and lymphocyte subsets, except for an increase in serum alkaline phosphatase levels. These findings suggest that CsA, even in a relatively low dose, reduces serum aminotransferase levels without serious side effects in patients with chronic-hepatitis C, although an antiviral effect was not noted.  相似文献   
2.
In a patient with sustained ventricular tachycardia, we obtained two different paced QRS morphologies from a single pacing site. In one QRS morphology the stimulus to the QRS complex was long, 150 msec, and in the other it was 100 msec. At the paced cycle length of 600 msec and the stimulus output of 4 V, one QRS morphology with the stimulus to the onset of QRS activation (St-QRS) interval of 150 msec was observed. At the paced cycle length of 400 msec, the other QRS morphology with a St-QRS interval of 100 msec was observed alternatively with the former. At the paced cycle length of 353 msec or 316 msec, the latter with a shorter St-QRS interval was exclusively observed. When the stimulus output was increased from 4 to 10 V, keeping with the paced cycle length at 400 msec, the St-QRS interval was shortened from 100 to 80 msec. For the two QRS morphologies with two St-QRS intervals, two slowly conducting pathways would be responsible. The site of the block in the faster pathway must be located at the proximity of the pacing site and the conduction at a shorter paced cycle length would be explained by "supernormal conduction."  相似文献   
3.
Various types of fibromatosis have been reported in infancy and early childhood. We describe an infant with diffuse fibromatosis on the scalp. A one year and five months-old girl showed a diffuse and hard mass 3 × 5 cm in diameter and no tenderness on the scalp. Two months later, the size of the mass had increased and several other tumors appeared on the lateral head. The magnetic resonance imaging (MRI) disclosed that a large and diffuse tumor had spread from the frontal to occipital head; a ‘helmet-like’ configuration of the tumor was exhibited on sagittal MR images. The tumor showed high signal intensity on T2-weighted images and was enhanced with Gd-DTPA. Histological examination showed a fibroblastic proliferation with intervening thick collagen bundles. The patient was diagnosed as having diffuse fibromatosis. The tumor at the resection site immediately recurred, whereas the tumor in the frontal head showed marked regression. Three months after the resection, new tumors appeared in the occipital head. The size and number of these tumors have remained unchanged for more than 18 months. The sites and appearance of the tumors were identical to that of juvenile hyaline fibromatosis (JHF) in this patient. However, JHF usually includes fibroblasts associated with large amounts of hyalinized collagen-like material, which were not present in our patient. The different histology of JHF comparing our case and other reported cases may depend on the different phase of the disease progression at resection. Long-term observation is necessary for the appropriate diagnosis and evaluation of prognosis in this patient.  相似文献   
4.
We describe a higher magnifying power operating microscope system to improve one method of high-quality microsurgical clipping for cerebral aneurysm in some cases. This higher magnification is achieved by a new lens design in the optical system, which makes the image of the object very clear at high magnifications (distinctiveness of 7 μm). This higher-resolution operating microscope system provides the surgeon with higher-magnified images (at the maximum of more than 30× magnifications as each working distance) in the operating field. The magnifications can be changed from low power (2.9×) to high power (62.0×) depending on the circumstances in a given procedure. We have used this operating microscope system on 11 patients with microsurgical clipping for cerebral aneurysms. Microsurgical treatment could be performed safely and precisely. All aneurysms were treated without any technical complications. We think that the use of this microscope would have potential benefits for microsurgical treatment for cerebral aneurysms because of better visualization.  相似文献   
5.
An ultrastructural study was undertaken on cartilage resorption at the site of initial endochondral bone formation in the mouse mandibular condyle on d 16 of pregnancy. After resorbing the bone collar, the osteoclasts extended their cell processes into the cartilage matrix and made contact with hypertrophic chondrocytes. By means of cell processes or vacuolar structures, these osteoclasts entrapped the calcified cartilage matrices, cell debris, and the degraded uncalcified cartilage matrices. In particular, since the calcified cartilage matrices were sometimes seen to be disrupted within the osteoclastic vacuolar structures, they were probably disposed of by the osteoclasts. Invading endothelial cells giving rise to capillaries also directly surrounded the degraded uncalcified cartilage matrices and small deposits of cell debris. In addition, hypertrophic chondrocytes that had attached to or were in the process of attaching to the invading osteoclasts often enclosed the small calcified cartilage matrices. Other cell types that have often been reported in other regions of cartilage resorption were not seen at the site of initial endochondral bone formation in this study. Our findings in relation to cartilage resorption may therefore represent unique features of the site of initial endochondral bone formation site. We consider that the manner of cartilage resorption is likely to vary by site, age, and species.  相似文献   
6.
Herein, we report on two clinical cases in which behavioral disturbances occurred due to frontal dysfunction. Both patients were treated successfully with behavioral intervention. In the first case, the patient's challenging behavior of repeatedly entering his wife's workplace and interrupting her work was reduced after the patient's wife changed her response to the behavior and her schedule prior to work to ensure that she spent time with him in the morning. In the second case, the patient's challenging behavior of urinating in the street was reduced by changing his walking route. The successful outcome in both cases suggests that behavioral intervention based on Antecedents, Behavior, and Consequences (ABC) analysis is useful in the management of behavioral disturbance due to frontal dysfunction.  相似文献   
7.
Attention is becoming increasingly focused on inhalation of nitric oxide (NO) as a selective pulmonary vasodilator. Its metabolite nitrogen dioxide (NO2), however, is a toxic molecule. The purpose of the present study was to evaluate the safety of a NO inhalation system using a conventional infant respirator from the viewpoint of NO2 production. The NO inhalation system consisted of a standard neonatal ventilator, a neonatal circuit and a test lung. The NO concentration was increased from 0 up to 19 ppm. At each level of NO, the oxygen (O2) concentration was changed from 21 to 100%. The NO and NO2 concentrations were measured with a chemiluminescence analyzer using a molybdenum converter. The NO2 concentration was increased when either the O2 or the NO concentration was increased. The maximum concentration of NO2 was 0.10 ± 0.02 ppm when the concentrations of NO and O2 were 19 ppm and 100% respectively. The NO inhalation system, using a conventional infant respirator, can be used safely when monitoring NO and NO2 concentrations.  相似文献   
8.
A female infant with 21 trisomy syndrome associated with congenital chylothorax was reported. She was born at a gestational age of 34 weeks by Cesarean section because of fetal hydrothorax and hydrops fetus, confirmed by ultrasonography at 32 weeks. Emergent resuscitation and immediate thoracentesis were performed soon after birth. After beginning breast feeding, the serous pleural fluid became opalescent and a diagnosis of congenital chylothorax was made. Feeding was changed to medium-chain triglyceride (MCT) feeding and the production of pleural effusion disappeared after thoracentesis was performed several times. Accumulating evidence suggested that MCT feeding and intermittent thoracentesis under echo guide were effective. Some reports on patients, including this one, suggest that there may be more patients with 21 trisomy associated with congenital hydrothorax. Therefore, congenital hydrothorax might be listed as a complication of 21 trisomy.  相似文献   
9.
Abstract  Mini Mental State Examination (MMSE), Brief Psychiatric Rating Scale (BPRS) and subscales of the BPRS were performed on 73 elderly inpatients (mean age: 67.9 years; standard deviation: 7.2; range: 60–89) diagnosed with DSM-III-R chronic schizophrenia. Forty of the subjects were men and 33 were women. A significant negative correlation was observed between MMSE and the age, factor negative, factor depressive, and total score of BPRS. We believe, however, that it is relatively sufficient to screen for demented illness of schizophrenics using MMSE when considering the age and the psychiatric symptoms (especially negative or depressive symptoms). Forty-eight (66%) of the 73 patients were categorized as 'demented' by MMSE. These results suggest that the aged inpatients with schizophrenia in a hospital showed certain kinds of cognitive deficits (including senile dementia) more frequently than the general population.  相似文献   
10.
Abstract: This study examined the effects of high-frequency current on pacemakers. Pacemakers were implanted in mongrel dogs, gastric mucosal resection was performed endoscopically using monopolar and bipolar snares, and the times for resection and magnitude of interference current (IC) in the myocardial electrodes were compared. The time for resection was 9.56±2.87 seconds with a monopolar snare and 0.82±0.13 seconds with a bipolar snare (p<0.01). The magnitude of the IC was 0.59±0.26 mV with a monopolar snare and 0.26±0.12 mV with a bipolar snare (p<0.01). The times required for resection and the magnitude of the IC using a bipolar snare in the coagulation mode at an output of approximately 12 W were 1.97±0.65 seconds and 0.03±0.02 mV, respectively, and those in the cutting mode were 1.68±0.50 seconds and 0.07±0.04 mV, respectively. The magnitude of the IC was significantly less (p<0.01), but the time required for resection was longer in the coagulation mode. No abnormalities were noted in the pacemaker mode in any of the 10 pacemakers examined after mucosal resection with high-frequency current at an output of 300 W. These results suggest that endoscopic therapy using high-frequency current can be performed more safely with a bipolar snare than with a monopolar snare in patients with pacemakers. In addition, the selection of the endoscope mode is considered to be important. (Dig Endosc 1999; 11: 150–157)  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