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   9005篇
  免费   592篇
  国内免费   64篇
耳鼻咽喉   117篇
儿科学   319篇
妇产科学   154篇
基础医学   1259篇
口腔科学   847篇
临床医学   784篇
内科学   1786篇
皮肤病学   260篇
神经病学   603篇
特种医学   310篇
外科学   1067篇
综合类   76篇
一般理论   3篇
预防医学   899篇
眼科学   176篇
药学   606篇
中国医学   78篇
肿瘤学   317篇
  2023年   106篇
  2022年   170篇
  2021年   311篇
  2020年   192篇
  2019年   257篇
  2018年   354篇
  2017年   258篇
  2016年   283篇
  2015年   332篇
  2014年   424篇
  2013年   500篇
  2012年   679篇
  2011年   695篇
  2010年   402篇
  2009年   375篇
  2008年   520篇
  2007年   503篇
  2006年   432篇
  2005年   360篇
  2004年   294篇
  2003年   246篇
  2002年   229篇
  2001年   143篇
  2000年   127篇
  1999年   148篇
  1998年   132篇
  1997年   106篇
  1996年   118篇
  1995年   86篇
  1994年   86篇
  1993年   54篇
  1992年   52篇
  1991年   64篇
  1990年   41篇
  1989年   59篇
  1988年   62篇
  1987年   47篇
  1986年   40篇
  1985年   41篇
  1984年   30篇
  1983年   20篇
  1982年   26篇
  1981年   17篇
  1980年   31篇
  1979年   21篇
  1977年   17篇
  1976年   19篇
  1975年   17篇
  1974年   16篇
  1973年   15篇
排序方式: 共有9661条查询结果,搜索用时 0 毫秒
21.
22.
23.
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.  相似文献   
24.
BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.  相似文献   
25.
26.
OBJECTIVE: Although cutaneous leishmaniasis (CL) occurs mostly in the facial area, periocular involvement accounts for 2-5% of the facial lesions. CL lesions localized in the periocular region can easily be confused with various other diseases. The aim of this study was to examine the frequency of periocular involvement in CL in the Cukurova region of Turkey, as well as the clinical characteristics, diagnosis and methods of treatment of this disease. METHODS: Between December 1998 and December 2004, patients who were diagnosed with CL were evaluated prospectively with respect to periocular involvement. RESULTS: From the 2066 patients evaluated with CL, 2622 lesions were identified. In 59 (2.9%) of these patients, a total of 66 (2.5%) lesions were located in the periocular area. Thirty-two (48.5%) of these lesions were of the papular type, 15 (22.7%) the nodulo-ulcerative type, 10 (15.2%) the plaque type, and nine (13.6%) the nodular type. Dacryocystitis was identified in four patients with periocular involvement. Over the follow-up period, no ocular or periocular deformities or complications developed in these patients. CONCLUSION: Patients suspected of CL should be evaluated and treated early in the course of their disease to prevent any permanent ocular or periocular deformities.  相似文献   
27.
28.
Zolmitriptan (ZomigTM) is a 5HT1B/1D agonist which has the ability to cross the intact blood-brain barrier to access central as well as peripheral receptors. Because of the potential for central nervous system side effects, this randomized, double-blind, placebo-controlled, 6-period crossover study evaluated the effects of 2.5 and 5 mg doses of zolmitriptan on psychomotor performance and investigated any pharmacodynamic or pharmacokinetic interaction with diazepam. Twelve healthy volunteers received the following "treatments" as single doses: zolmitriptan 2.5 mg, zolmitriptan 5 mg, diazepam 10 mg, zolmitriptan 2.5 mg+diazepam 10 mg, zolmitriptan 5 mg+diazepam 10 mg and placebo. Pre-dose and at 1, 4, 8, and 24 h post-dose, the following validated battery of psychomotor tests was performed: Bond-Lader visual analogue scales (calmness, contentedness, and alertness factors), critical flicker fusion test, choice reaction time (recognition, motor, and total reaction times), finger-tapping test, number cancellation test and digit symbol substitution test. Plasma concentrations of zolmitriptan, its active metabolite, and diazepam and its active metabolites were measured at the same timepoints. Zolmitriptan 2.5 and 5 mg had no effect on psychomotor function when given alone. In contrast, diazepam 10 mg had profound effects, consistent with its sedative properties, but there was no synergism on concomitant administration of either dose of zolmitriptan. Plasma concentrations of zolmitriptan, diazepam, and their respective active metabolites were similar when the two drugs were given alone or in combination.  相似文献   
29.
Microorganisms are very powerful tools for the supply of information about the toxic effects of lipophilic compounds, since an impairment of cell growth usually occurs as a result of perturbations related, in most cases, with the partition of toxicants in membranes. The thermophilic eubacterium Bacillus stearothermophilus has been used as a model system to identify α- and β-endosulfan interactions with the membrane possibly related with the insecticide toxicity. Two approaches have been pursued: (a) bacterial growth is followed and the effects of endosulfan isomers determined; (b) biophysical studies with the fluorescent fluidity probe 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed to assess the effects of α- and β-endosulfan on the organization of the membrane lipid bilayer. The effects on growth were quantitatively evaluated by determination of growth parameters, namely the lag phase, the specific growth rate and the cell density reached by cultures in the stationary phase. Growth inhibition by α and β-endosulfan dependent on the concentration is diminished or removed by the addition of 2.5 m Ca2+ to bacterial cultures. Fluorescence DPH polarization consistently showed opposite effects of Ca2+ and α- and β-endosulfan on the physical state of bacterial polar lipid dispersions.  相似文献   
30.
An attempt was made to characterize lipemic levels according to sex, age and presence or absence of cardiovascular disease risk factors, in a population of 3,792 people between the ages of 20 and 59, in terms of smoking habits, obesity, family history of diabetes and use of oral contraceptives. Those individuals who did not present any of the risk factors mentioned were classified as "exempt". After submitting the data to variance analysis it was found that: for men between 20 and 49 years of age there were high significant differences in the averages obtained for the seric levels of total lipids, triglycerides and total cholesterol between "exempt" and obese and "exempt" and obese with a family history of diabetes; for the 50 to 59 age group there were significant differences in the average of the values corresponding to the seric levels of total lipids between "exempt" and those individuals in whom obesity appeared associated with smoking habits or associated with a family history of diabetes. The averages obtained for seric triglycerides were significantly different between "exempt" and non-obese with a family history of diabetes, obese, obese smokers and obese with a family history of diabetes. On the other hand, the averages relating to seric levels of total cholesterol were different, at significant levels, between "exempt" and obese smokers; the risk represented by the smoking habit showed no relevance with regard to the lipemic levels in any group except for that of men between 30 and 39 years of age. In their case, there were significant differences between the averages obtained for the seric levels of total lipids, triglycerides and total cholesterol, between "exempt" and smokers and between "exempt" and obese smokers. It is to be noted that the differences obtained with regard to the averages relating to lipemic levels as between "exempt" and obese were less those obtained between "exempt" and obese smokers, thus showing the possible relevance of the risk presented by the smoking habit; -- among the women there were less accentuated differences in the averages corresponding to the lipemic levels as between "exempt" and those who presented one or more risk factors. Thus, for the age group from 20 to 29 there were significant differences in the averages obtained for total lipids as between "exempt" and obese.(ABSTRACT TRUNCATED AT 400 WORDS)  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