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   196篇
  免费   23篇
儿科学   8篇
基础医学   70篇
口腔科学   9篇
临床医学   25篇
内科学   30篇
皮肤病学   4篇
神经病学   12篇
特种医学   19篇
外科学   13篇
综合类   1篇
预防医学   3篇
眼科学   1篇
药学   10篇
中国医学   1篇
肿瘤学   13篇
  2022年   2篇
  2021年   2篇
  2018年   3篇
  2014年   2篇
  2013年   3篇
  2012年   4篇
  2011年   7篇
  2010年   7篇
  2009年   4篇
  2008年   4篇
  2007年   11篇
  2006年   4篇
  2005年   2篇
  2004年   5篇
  2003年   4篇
  2002年   7篇
  2001年   8篇
  2000年   5篇
  1999年   6篇
  1998年   3篇
  1997年   2篇
  1992年   4篇
  1991年   2篇
  1989年   2篇
  1988年   5篇
  1987年   10篇
  1986年   7篇
  1985年   6篇
  1984年   5篇
  1983年   4篇
  1981年   6篇
  1980年   1篇
  1979年   4篇
  1978年   7篇
  1977年   1篇
  1976年   6篇
  1975年   3篇
  1974年   4篇
  1973年   2篇
  1972年   6篇
  1971年   6篇
  1970年   1篇
  1969年   4篇
  1968年   6篇
  1967年   6篇
  1966年   2篇
  1965年   1篇
  1964年   1篇
  1960年   2篇
  1930年   1篇
排序方式: 共有219条查询结果,搜索用时 15 毫秒
21.
22.
BACKGROUND: Emedastine difumarate 0.05% ophthalmic solution and ketotifen fumarate 0.025% ophthalmic solution are 2 topical antiallergic agents available in the United States and other countries. Emedastine is indicated for the temporary relief of the signs and symptoms of allergic conjunctivitis. Ketotifen is indicated for the temporary relief of ocular itching caused by allergic conjunctivitis. OBJECTIVE: The purpose of this study was to compare the efficacy of these agents in the temporary relief of ocular itching due to allergic conjunctivitis. The 2 agents were compared with each other and with placebo (artificial tears) using the conjunctival allergen challenge (CAC) model. METHODS: This was a single-center, randomized, double-masked, placebo-controlled study. At visit 1, CAC was performed on eligible subjects to identify the dose required to elicit a positive allergic reaction. Subjects returned after 7 days for visit 2 to confirm the allergen dose. On day 14 (+/-3) of the study, enrolled subjects were randomized to 1 of 3 treatment groups: emedastine in I eye and placebo in the other, ketotifen in 1 eye and placebo in the other, or emedastine in 1 eye and ketotifen in the other. In 25 subjects, bilateral CAC was performed 5 minutes after study medication instillation. In a second group of 20 subjects, CAC was performed 15 minutes after medication instillation. Itching was graded according to a standardized 5-point scale (0 = none to 4 = severe itching) at 3, 5, and 10 minutes postchallenge. Differences in efficacy scores between treatments and versus placebo were compared using 2-sample t tests of equal variance. RESULTS: A total of 45 patients (mean age, 41.2 years) received treatment: 16 received emedastine in 1 eye and ketotifen in the other; 14 received emedastine in 1 eye and placebo in the other; and 15 received ketotifen in 1 eye and placebo in the other. Both emedastine and ketotifen significantly inhibited itching (P < 0.05) compared with placebo at all time points after the 5- and 15-minute CAC. Mean raw scores for the active treatments were not statistically different. The mean itching efficacy scores were also not statistically different between active treatments. No adverse events were reported in this study. CONCLUSION: The results of this study suggest that emedastine and ketotifen are not significantly different with respect to anti-itching efficacy in the CAC model of acute allergic conjunctivitis.  相似文献   
23.
Congenital myotonic dystrophy (CMD) is characterized by hypotonia, facies myopathica, feeding and respiratory problems, skeletal deformities and polyhydramniosis. It is an autosomal-dominant disorder transmitted via the mother. The diagnosis can as a role be confirmed by examining the mother, but can fail as she might be asymptomatic. During a nine year period, eight children were diagnosed as CMD which means an incidence of one case per approximately 3,500 live births. The diagnosis was confirmed in six of the mothers. The two floppy infants, where positive inheritance could not be proven, showed most of the signs and symptoms described in CMD. Four children died, two from respiratory insufficiency and two suddenly and unexpectedly. CMD may be one less common cause of sudden infant death syndrome (SIDS). The four children who survived displayed delayed psychomotor development.  相似文献   
24.
BACKGROUND: Racemic albuterol (RAC) is an equal mixture of (R)-albuterol and (S)-albuterol. Only the (R)-isomer, levalbuterol (LEV), is therapeutically active. Lower doses of LEV, devoid of (S)-albuterol, have demonstrated efficacy comparable to that of higher doses of the (R)-isomer administered as a component of RAC. OBJECTIVE: The purpose of this study was to determine whether LEV results in improved safety and efficacy in children. METHODS: Asthmatic children aged 4 to 11 years (n = 338; FEV(1), 40% to 85% of predicted) participated in this multicenter, randomized, double-blinded study and received 21 days of 3-times-a-day treatment with nebulized LEV (0.31 or 0.63 mg), RAC (1.25 or 2.5 mg), or placebo. The primary endpoint was FEV(1) (peak percent change). Adverse events, clinical laboratory test results, vital signs, and electrocardiograms were evaluated for safety. RESULTS: All active treatments significantly improved the primary endpoint in comparison with placebo (P < .001). Significant differences in FEV(1) were noted immediately after nebulization (median change, 2.0%, 19.0%, 18.1%, 12.4%, and 15.6% for placebo, LEV 0.31 and 0.63, RAC 1.25 and 2.5 mg, respectively; P < .05 vs placebo; P < .05 for LEV 0.31 and 0.63 vs RAC 1.25 mg). LEV 0.31 mg was the only treatment not different from placebo for changes in ventricular heart rate, QT(c) interval, and glucose (P > .05). All active treatments decreased serum potassium (range, -0.3 to -0.6; P < .002 vs placebo), and RAC 2.5 mg caused the greatest change (P < .005 vs other actives). In a patient subset with severe asthma, a dose-response relationship was observed for levalbuterol, indicating that higher doses were more effective. CONCLUSION: LEV was clinically comparable to 4- to 8-fold higher doses of RAC, and it demonstrated a more favorable safety profile. LEV 0.31 mg should be used as the starting dose in 4-11 year old children with mild to moderate persistent asthma. Patients with severe disease might benefit from higher doses.  相似文献   
25.
26.
The role of ascorbic acid in senile cataract.   总被引:3,自引:0,他引:3       下载免费PDF全文
The reductone ascorbic acid, present in the crystalline lens in concentrations higher than those of glucose, is capable of undergoing nonenzymatic "browning" in the presence of lenticular proteins. We studied the nonenzymatic browning with ascorbate in model systems employing bovine serum albumin and lens crystallins. When bovine serum albumin, alpha-crystallin, or gamma-crystallin was incubated with [14C]ascorbic acid, the formation of yellow and then brown condensation products appeared to correlate with increasing protein-associated radioactivity. The fluorescence spectrum of these products was similar to that of homogenates of human cataractous lenses. We suggest that the nonenzymatic reaction of lens crystallins with ascorbic acid may contribute, at least in part, to the color changes of aging lenses and to the physical lenticular deterioration leading to senile cataract. High dietary intake of ascorbic acid did not affect the fluorescence spectrum of murine lenses; thus, we assume that the speed and extent of the lenticular browning reactions must depend on a deterioration of other factors of the multicomponent antioxidant system of the eye.  相似文献   
27.
Myoglobinuria associated with herpes-group viral infections   总被引:2,自引:0,他引:2  
Two cases of myoglobinuria were associated with herpes-group viral infection (herpes simplex and Epstein-Barr). Muscle atrophy and acute renal failure were important complications. No evidence of direct invasion of muscle fibers by virus was found, nor was the severity of myoglobinuria correlated with histologic appearance of muscle.  相似文献   
28.
Cooling before circulatory arrest or ischemic arrest has been reported to influence myocardial performance in isolated neonatal hearts. The aim of the present study was to analyze indices of myocardial contractility and relaxation in an in vivo neonatal model after deep hypothermic circulatory arrest (DHCA). DHCA (18°C; DHCA group; n = 8) or mild hypothermic cardiopulmonary bypass ([MH-CPB] 32°C; MH-CPB group; n = 10) was applied in newborn piglets. After reperfusion (60 and 120 min), left ventricular dP/dt(max) increased in DHCA and MH-CPB, while-dP/dt(max) decreased slightly in DHCA and increased in MH-CPB. Nevertheless, the differences between the two groups did not reach statistical significance. In conclusion, left ventricular contractility remained stable after reperfusion following DHCA, to some degree at the expense of the diastolic function.  相似文献   
29.
The human epidermal growth factor receptor (HER) family members are targeted by a growing numbers of small molecules and monoclonal antibodies. Resistance against the epidermal growth factor receptor (EGFR) and HER2-targeting agents is a clinically relevant problem forcing research on optimizing targeting of the HER family. In view of its overexpression in tumors, and compensatory role in HER signaling, HER3 has gained much interest as a potential additional target within the HER family. It is the only member of the HER family lacking intrinsic tyrosine kinase activity and therefore its role in cancer has long been underestimated. Drugs that block HER3 or interfere with HER3 dimer signaling, including fully human anti-HER3 antibodies, bispecific antibodies and tyrosine kinase inhibitors (TKIs), are currently becoming available. Several compounds have already entered clinical trial. In the meantime potential biomarkers are tested such as tumor analysis of HER3 expression, functional assays for downstream effector molecules and molecular imaging techniques. This review describes the biology and relevance of HER3 in cancer, agents targeting HER3 and potential biomarkers for effect of HER3-targeting.  相似文献   
30.

Background  

Biological control methods are once again being given much research focus for malaria vector control. This is largely due to the emerging threat of strong resistance to pesticides. Larvivorous fish have been used for over 100 years in mosquito control and many species have proved effective. In the western Kenyan highlands the larvivorous fish Oreochromis niloticus L. (Perciformes: Cichlidae) (formerly Tilapia nilotica) is commonly farmed and eaten but has not been previously tested in the field for malaria mosquito control.  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