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   31570篇
  免费   3260篇
  国内免费   688篇
耳鼻咽喉   202篇
儿科学   606篇
妇产科学   284篇
基础医学   3339篇
口腔科学   925篇
临床医学   4515篇
内科学   6058篇
皮肤病学   442篇
神经病学   2626篇
特种医学   763篇
外国民族医学   12篇
外科学   2604篇
综合类   3791篇
现状与发展   4篇
预防医学   3160篇
眼科学   1319篇
药学   1608篇
  18篇
中国医学   1071篇
肿瘤学   2171篇
  2024年   330篇
  2023年   762篇
  2022年   1164篇
  2021年   1778篇
  2020年   1429篇
  2019年   1419篇
  2018年   1330篇
  2017年   1331篇
  2016年   1302篇
  2015年   1318篇
  2014年   2011篇
  2013年   2251篇
  2012年   1686篇
  2011年   1721篇
  2010年   1440篇
  2009年   1401篇
  2008年   1327篇
  2007年   1374篇
  2006年   1197篇
  2005年   1049篇
  2004年   913篇
  2003年   824篇
  2002年   749篇
  2001年   636篇
  2000年   530篇
  1999年   452篇
  1998年   424篇
  1997年   339篇
  1996年   328篇
  1995年   271篇
  1994年   267篇
  1993年   244篇
  1992年   212篇
  1991年   218篇
  1990年   195篇
  1989年   130篇
  1988年   133篇
  1987年   107篇
  1986年   110篇
  1985年   174篇
  1984年   126篇
  1983年   104篇
  1982年   97篇
  1981年   78篇
  1980年   69篇
  1979年   37篇
  1978年   40篇
  1977年   19篇
  1976年   26篇
  1973年   13篇
排序方式: 共有10000条查询结果,搜索用时 99 毫秒
21.
刘秋菊 《中国医药》2006,1(5):297-299
目的分析并比较NE系列的两种冲击波源碎石机治疗输尿管结石的疗效、碎石时的疼痛程度、碎石时间及副作用。方法回顾性分析应用NE-IV型液电冲击波源碎石机治疗输尿管结石患者1290例及应用NE-VB型电磁冲击波源碎石机治疗输尿管结石患者1196例的临床资料,并进行疗效、碎石时间、碎石时的疼痛程度及副作用的比较。结果应用电磁冲击波源碎石机治疗输尿管上段结石患者的总有效率为85.4%,治疗时间23~60min,平均(35.3±5.7)min;输尿管下段结石患者的总有效率为94.6%,治疗时间3~60min,平均(30.5±6.1)min。碎石时患者的疼痛感觉轻。液电冲击波源碎石机治疗的输尿管上段结石患者的总有效率为75.7%,治疗时间25~110min,平均(38.0±9.8)min;输尿管下段结石为85.7%,治疗时间4~90min,平均(35.8±7.7)min。碎石时患者的疼痛感觉明显。此外,肾绞痛、血尿、恶心、呕吐、皮肤瘀斑等副作用明显高于电磁冲击波源碎石机治疗组。结论电磁冲击波源碎石机治疗输尿管结石疗效优于液电冲击波源碎石机,而且更安全、有效、痛苦小。  相似文献   
22.
Two patients are described who had pseudo-oversensing of T waves during follow-up testing of the Medtronic PCD. Each patient exhibited appropriate T wave sensing following closely coupled spontaneous QRS complexes to subthreshold stimuli without having T wave sensing following sensed or paced complexes. One patient also revealed T wave sensing following fusion beats. The occurrence of T wave sensing in these unique clinical situations was due to the auto-adjusting sensitivity threshold function used by the PCD. Recognition of this normal sensing function will prevent inappropriate reprogramming of the sensitivity or postpace refractory period, interventions that could potentially lead to ventricular tachyarrhythmia undersensing.  相似文献   
23.
The locations of the three disulfide bonds of eclosion hormone (EH) isolated from Manduca sexta were assigned by sequence analysis of thermolysin fragments and by comparison of a key heterodimeric fragment to regiospecifically synthesized parallel and antiparallel isomers. We elucidated the complete structure of Manduca EH as a 62-residue peptide which has three disulfide bonds between Cys14-Cys38, Cys18-Cys34, and Cys21-Cys49.  相似文献   
24.
AIMS: To characterize the determinants of diabetes-related emotional distress by treatment modality (diet only, oral medication only, or insulin). METHODS: A total of 815 primary care patients with Type 2 diabetes completed the Problem Areas in Diabetes (PAID) Scale and other questions. We linked survey data to a diabetes clinical research database and used linear regression models to assess the associations of treatment with PAID score. RESULTS: PAID scores were significantly higher among insulin-treated (24.6) compared with oral-treated (17.8, P < 0.001) or diet-treated patients (14.7, P < 0.001), but not different between oral- vs. diet-treated patients (P = 0.2). Group scores remained similar, but the statistical significance of their differences was reduced and ultimately eliminated after sequential adjustment for diabetes severity, HbA(1c), body mass index, regimen adherence, and self-blood-glucose monitoring. Insulin-treated patients reported significantly higher distress than oral- or diet-treated patients on 16 of 20 PAID items. 'Worrying about the future' and 'guilt/anxiety when ... off track with diabetes' were the top two serious problems (PAID >or= 5) in all treatment groups. Not accepting diabetes diagnosis was a top concern for oral- and diet-treated patients, and unclear management goals distressed diet-treated patients. CONCLUSIONS: Primary care patients treated with insulin reported higher diabetes-related emotional distress compared with oral- or diet-treated patients. Greater distress was largely explained by greater disease severity and self-care burdens. To improve diabetes-specific quality of life, clinicians should address patients' sense of worry and guilt, uncertain acceptance of diabetes diagnosis, and unclear treatment goals.  相似文献   
25.
The Depression Scale (DEPS), a new screening instrument for detecting depression in primary health care, was compared with the Hamilton Depression Scale (HDS) among 50 suicide attempters. Using the HDS as a gold standard, the positive and negative predictive values of the DEPS for the diagnosis of depression were 98% and 20%, respectively. The correlation between the total HDS scores and the total DEPS scores was 0.60. The DEPS may help general practitioners to detect depression among suicide attempters, but it should not be used to exclude depression.  相似文献   
26.
Electrophysiological examinations were done on 20 patients aged 40–71 years with recently diagnosed high grade non-Hodgkin's lymphomas. General chemotherapy and intrathecal chemotherapy in order to prevent central nervous system (CNS) involvement were begun. On the first day of chemotherapeutic cycle patients received intrathecally methotrexate (ITMTX) and prednisolone. Electrophysiological study was carried out twice in each subject: before ITMTX injection and a day after injection. The study procedure included: a conventional nerve conduction examination (peripheral conduction velocity and compound muscle action potential amplitude), the F wave latency and amplitude measurement and F ratio (F-M-1/2M) calculation for peroneal and tibial nerve bilaterally. Results of the first and the second examinations were statistically compared by t-Student's test. No significant differences between values of estimated parameters were found. The study revealed no recent alterations in proximal, paraspinal motor conduction and motor neuron excitability due to antidromical activation after single ITMTX administration.  相似文献   
27.
Abstract: The possibility on placing electrodes at Fpz-A2 instead of C3-A2 was investigated to obtain a more stable configuration avoiding obstruction by the hair. Our original system of alpha wave detection by a microcomputer was used, and a total of 22 all-night hypnograms of five healthy young students waa recorded. Pearson's moment correlation coefficients of alpha wave % between the two positions were 0.780–0.948. Except for one subject, alpha wave % taken at Fpz-A2 tended to be 3–5% lower than that at C3-A2. The above analysis indicates that using EEG electrode position of Fpz-A2 is valid and useful as a stable electrode configuration for a long-time monitoring.  相似文献   
28.
A 60-year-old Japanese man was hospitalized because of urinary leakage from the anus on October 3, 1994. Retrograde urethrography detected a fistula between the bulbous urethra and the rectum. Urethrocystoscopy revealed a tumor on the urethrorectal fistula. Tumor biopsy showed a well differentiated adenocarcinoma. Cystourethrectomy with fistulectomy, and ileal conduit urinary diversion were performed. Pathological examination revealed primary adenocarcinoma in the fistula with invasion to the prostatic urethra and bladder wall. The patient showed no evidence of a recurrence as of August, 1996.  相似文献   
29.
A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm2 in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.  相似文献   
30.
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