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   1085篇
  免费   51篇
  国内免费   6篇
耳鼻咽喉   11篇
儿科学   39篇
妇产科学   61篇
基础医学   110篇
口腔科学   5篇
临床医学   72篇
内科学   153篇
皮肤病学   4篇
神经病学   61篇
特种医学   33篇
外科学   369篇
综合类   47篇
一般理论   2篇
预防医学   53篇
眼科学   20篇
药学   42篇
  1篇
中国医学   16篇
肿瘤学   43篇
  2023年   5篇
  2022年   13篇
  2021年   21篇
  2020年   13篇
  2019年   24篇
  2018年   15篇
  2017年   13篇
  2016年   13篇
  2015年   19篇
  2014年   20篇
  2013年   35篇
  2012年   72篇
  2011年   64篇
  2010年   50篇
  2009年   43篇
  2008年   66篇
  2007年   63篇
  2006年   73篇
  2005年   51篇
  2004年   46篇
  2003年   42篇
  2002年   45篇
  2001年   41篇
  2000年   32篇
  1999年   24篇
  1998年   12篇
  1997年   8篇
  1996年   7篇
  1995年   8篇
  1994年   11篇
  1993年   7篇
  1992年   19篇
  1991年   21篇
  1990年   15篇
  1989年   21篇
  1988年   19篇
  1987年   21篇
  1986年   21篇
  1985年   13篇
  1984年   5篇
  1983年   8篇
  1982年   2篇
  1980年   2篇
  1979年   3篇
  1978年   7篇
  1973年   2篇
  1971年   1篇
  1969年   1篇
  1966年   1篇
  1958年   1篇
排序方式: 共有1142条查询结果,搜索用时 15 毫秒
81.
Augmentation of venous drainage by a venous anastomosis for pedicled flaps   总被引:1,自引:0,他引:1  
Recently several studies have addressed the venous problem and confirmed that venous ischemia is more injurious to tissue viability than arterial ischemia of equivalent duration. There are different methods of managing venous-compromised pedicled flaps. Between June 1996 and November 2003, our center treated two submental, five Becker, nine posterior interosseous, three distally based sural, and three colon pedicled flaps (22 flaps in total), which had venous congestion either at the time of flap elevation or immediately after inset of the flap. These cases of venous congestion were managed with an immediate additional venous anastamosis. After vein anastomosis, venous congestion reduced gradually, then improved, and finally disappeared completely in the postoperative follow-up days with all flaps surviving in their entirety. Reexploration was not required for the microsurgical venous anastomosis. In conclusion, flap necrosis resulting from venous congestion causes prolonged hospitalization, multiple debridements, and additional procedures to cover the exposed structures. Additional vein anastomosis, which is a simple, rapid, and reliable auxiliary procedure, may increase complete flap survival and lead to successful end results, both functional and cosmetic.  相似文献   
82.
83.
The dietary data from case-control studies of breast, prostate, and lung cancer in Hawaii revealed that saturated fat was a risk factor for these malignancies. The dietary intakes from the three studies were used to calculate the attributable risk (AR) due to saturated fat. For all ethnic groups combined, the ARs for the highest quartiles of intake were 14.9 percent for female breast cancer, 13.0 percent for prostate cancer, and 23.1 percent for male lung cancer. Our results suggested that a reduction of saturated fat to the lowest quartiles of intake could result in a 10 to 20 percent decrease in risk for these three cancers in Hawaii. We also examined the ethnic-specific risks associated with saturated fat consumption among the Japanese and the Caucasians in the three studies. The ARs for the highest quartiles of intake were notably higher among the Caucasians than the Japanese, primarily due to the difference in their dietary patterns. Although the calculated AR due to saturated fat was higher among the Caucasians than among the Japanese, all persons in the population would derive considerable benefit by reducing their intake of this nutrient.Authors are with the Epidemiology Program, Cancer Research Center of Hawaii, University of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813, USA. Address correspondence to Dr Hankin. This study was supported in part by NIH Grant PO1 CA 33619.  相似文献   
84.
Immunotherapy through oral routes is thought to be a valuable therapeutic option for asthma. The clinical and immunologic effects of sublingual immunotherapy (SLIT) in children with asthma caused by mites were evaluated in a double-blind, placebo-controlled study for 6 months. Patients (aged 6-12 yr) with mild-to-moderate asthma, with single sensitization to mite allergen, received either SLIT or placebo with a standardized Dermatophagoides pteronyssinus (D.p.)/D. farinae (D.f.) 50/50 extract. The cumulative dose was around 41824 IR, equivalent to 1.7 mg of D.p. and 3.0 mg of D.f. allergen. Symptom and medication scores were assessed throughout the study. Serum total immunoglobulin (Ig)E, eosinophil count, eosinophil cationic protein, specific IgE, specific IgG4, and skin sensitivity were evaluated before starting the treatment and after the treatment period. Twenty patients completed the study. At the beginning of the treatment, no differences were observed between the groups for symptom and medication scores, skin sensitivity, or immunologic parameters. After 6 months of treatment, there was a significant difference in nighttime asthma symptom scores and specific IgG4 (p < 0.05) in the SLIT group compared with the placebo group. Daytime symptom and medication scores, total IgE, eosinophil count, forced expiratory volume in 1 s, and mean evening peak expiratory flow rate reached significant differences in the SLIT group during the treatment period (p < 0.05). No severe adverse effects were reported. Our results revealed that treatment for 6 months with SLIT is clinically effective in decreasing asthmatic symptoms and medication use in children with mild-to-moderate asthma because of mite sensitivity. The clinical usefulness of this form of immunotherapy and the mechanism underlying its immunologic effects deserve further studies.  相似文献   
85.
目的 探讨女性盆腔器官脱垂(POP)患者尾骨肌厚度的变化。方法 收集2014年8月至2015年1月于中国医科大学附属盛京医院就诊的女性盆腔器官脱垂患者(观察组)25例,无器官脱垂及其他盆腔疾病志愿者(对照组)25例。于平静状态下进行磁共振(MRI)扫描,分别选取髋关节上份平面,髋关节中份平面及尾骨-子宫平面三个层面,测量、比较双侧尾骨肌厚度,并通过计算不同层面肌肉厚度的差值表现尾骨肌厚度的变化程度。对测量结果进行独立样本t检验。结果 观察组与对照组内左、右侧尾骨肌厚度差异无统计学意义(P>0.05);观察组双侧尾骨肌平均厚度与对照组相比差异无统计学意义(P>0.05);观察组左、右侧尾骨肌厚度差值[(3.51±1.79)mm、(3.62±  相似文献   
86.
Summary Numerous revascularization procedures are used for the treatment of vasculogenic impotence. In an animal model we created three different types of bypasses: inferior epigastric artery to dorsal penile artery, to dorsal artery and to dorsal vein (anastomotic arteriovenous fistula), and to dorsal vein alone. Epigastro-dorsal anastomoses remained fully patent without anticoagulants in 3 of 4 animals. With erection the flow in the inferior epigastric artery and the retrograde flow in the dorsal artery (towards the cavernous artery) increased significantly. In the 4 studies incorporating an anastomotic arteriovenous fistula we could not establish a clear reason to incorporate the artery; runoff was demonstrated only to the venous system. Arterial bypass to the dorsal vein with a simulated emissary vein increased outflow resistance as well as improved intracorporeal pressure during erection of the corpora in 4 animals. As resting pressure was also elevated, the penile smooth muscle might be at risk for further degeneration with this procedure.Part of this paper was presented at the 10th Symposium of the Association for Experimental Urology of the German Urological Society, June 21–23, 1990, Munich, FRG  相似文献   
87.
88.
In the not too distant past, the physician caring for the impotent patient had few therapeutic options. With the recent advances in penile pharmacotherapy, vascular surgery, and prosthetics, several possibilities for treatment are now available. Before a decision is made, however, numerous factors must be taken into consideration: age, manual dexterity, cause of erectile dysfunction, psychological attitude, and social considerations. Clearly, the choice of therapy for impotence must now be made on an individual basis after a careful diagnostic evaluation and in-depth consultation with the patient. Only then can the treatment that offers the highest likelihood of success, both functional and emotional, be chosen.  相似文献   
89.
The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
90.
OBJECTIVE: Outer hair cells (OHCs) of the inner ear rapidly convert electrical gradients into mechanical force, enhancing cochlear sensitivity and frequency selectivity. We investigated the effect of chlorpromazine, an antipsychotic medication that alters membrane biomechanics, on OHC electromotility. STUDY DESIGN: Isolated guinea pig outer hair cells were perfused with chlorpromazine under whole-cell patch-pipette recording conditions. Electromotile responses were measured. RESULTS: A dramatic, reversible, dose-dependent depolarization of voltage at peak capacitance (V(pkCm)) was seen with chlorpromazine treatment. The gain of the electromotile response was maximal near V(pkCm) both before and after chlorpromazine application. Unlike the 3 other agents that alter electromotility (salicylate, lanthanides, membrane tension), chlorpromazine did not change peak capacitance (Cm(pk)), which varies directly with maximal electromotile gain. CONCLUSION: Chlorpromazine changes the membrane voltage at which OHCs exhibit maximal electromotile gain, without changing the magnitude of electromotile responses. SIGNIFICANCE: Chlorpromazine may diminish hearing thresholds or otoacoustic emissions in large doses.  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