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   7852篇
  免费   440篇
  国内免费   56篇
耳鼻咽喉   112篇
儿科学   169篇
妇产科学   55篇
基础医学   938篇
口腔科学   211篇
临床医学   551篇
内科学   2040篇
皮肤病学   175篇
神经病学   462篇
特种医学   289篇
外科学   1500篇
综合类   42篇
预防医学   243篇
眼科学   109篇
药学   507篇
中国医学   9篇
肿瘤学   936篇
  2023年   79篇
  2022年   151篇
  2021年   282篇
  2020年   141篇
  2019年   165篇
  2018年   263篇
  2017年   192篇
  2016年   230篇
  2015年   232篇
  2014年   249篇
  2013年   319篇
  2012年   479篇
  2011年   560篇
  2010年   286篇
  2009年   248篇
  2008年   413篇
  2007年   447篇
  2006年   422篇
  2005年   393篇
  2004年   414篇
  2003年   417篇
  2002年   368篇
  2001年   138篇
  2000年   133篇
  1999年   137篇
  1998年   87篇
  1997年   74篇
  1996年   62篇
  1995年   59篇
  1994年   54篇
  1993年   49篇
  1992年   70篇
  1991年   86篇
  1990年   63篇
  1989年   68篇
  1988年   58篇
  1987年   58篇
  1986年   55篇
  1985年   52篇
  1984年   35篇
  1983年   26篇
  1981年   12篇
  1980年   14篇
  1979年   28篇
  1978年   27篇
  1977年   16篇
  1975年   12篇
  1974年   13篇
  1968年   15篇
  1967年   12篇
排序方式: 共有8348条查询结果,搜索用时 15 毫秒
101.
This retrospective study clarified the success rate of endoscopic endodontic surgeries and identified predictors accounting for successful surgeries. In this retrospective study, 242 patients (90 males, 152 females) who underwent endoscopic endodontic surgery at a single general hospital and were diagnosed through follow-up one year later were included. Risk factors were categorized into attributes, general health, anatomy, and surgery. Then, the correlation coefficient was calculated for the success or failure of endodontic surgery for each variable, the odds ratio was calculated for the upper variable, and factors related to the surgical prognosis factor were identified. The success rate of endodontic surgery was 95.3%, showing that it was a highly predictable treatment. The top three correlation coefficients were post, age, and perilesional sclerotic signs. Among them, the presence of posts was the highest, compared with the odds ratio, which was 9.592. This retrospective study revealed the success rate and risk factors accounting for endoscopic endodontic surgeries. Among the selected clinical variables, the presence of posts was the most decisive risk factor determining the success of endodontic surgeries.  相似文献   
102.
Laparoscopic pancreatic surgery is evolving rapidly; however, the surgical treatment of periampullary tumors is still fraught with challenges, such as technical difficulty and the appropriateness of oncologic treatment for these patients. We describe how we performed laparoscopic pancreaticoduodenectomy (LPD) combined with minilaparotomy successfully in six consecutive patients. This procedure consisted of two surgical phases: safe laparoscopic surgery, including the Kocher maneuver, tunneling behind the pancreatic neck, and dissecting along the uncinate process with magnified vision; and a secure open approach with complete skeletonization of the hepatoduodenal ligament and alimentary tract reconstruction, performed similarly to conventional pancreaticoduodenectomy, under direct visualization through the minilaparotomy. By performing this procedure, we combined a safe and secure minilaparotomy approach under direct vision with a less invasive laparoscopic approach providing a magnified image. Our experience demonstrates that LPD combined with minilaparotomy is technically feasible for selected patients with periampullary tumors.  相似文献   
103.
Abstract

Objective: Core beliefs about negative-self are beliefs about self-deficiencies in basic aspects of human adaptation. Meanwhile, neuroticism is a personality trait characterised by negative emotionality, i.e., a tendency to react to stress with negative emotions. The present study tested the hypothesis that core beliefs about negative-self are implicated in neuroticism.

Methods: The subjects were 309 Japanese healthy volunteers. Core beliefs about negative-self were evaluated by the Brief Core Schema Scales, and neuroticism was evaluated by the NEO Personality Inventory-Revised.

Results: In both multiple regression analysis and structural equation modelling, higher neuroticism was strongly predicted by higher levels of core beliefs about negative-self.

Limitations: The present study cannot determine the causal relationship between core beliefs about negative-self and neuroticism, because of its cross sectional design.

Conclusions: The present study suggests that core beliefs about negative-self are deeply implicated in neuroticism.
  • Key Points
  • Implication of core beliefs about negative-self in neuroticism was examined.

  • Neuroticism was predicted by higher levels of these core beliefs.

  • These core beliefs may be involved in negative emotionality of neuroticism.

  相似文献   
104.
105.
Fatty liver is commonly associated with alcohol or metabolic syndrome. We aimed to examine the longitudinal aspects of fatty liver, and clarify the independent predictors for the development or regression of fatty liver. In the present study, the clinical features of 1578 Japanese adults (1208 men and 370 women; 35 to 69 years of age) who visited our center both in 2000 and 2007–2008 were recorded and compared, including liver status diagnosed by ultrasonography. Of the 1578 participants, 217 (13.8%) showed fatty liver development, and 74 (4.7%) showed fatty liver regression. Logistic regression analysis revealed that body mass index and percentage body fat were strongly associated with the development or regression of fatty liver. Metabolic syndrome-related disorders such as serum levels of total cholesterol, triglyceride, uric acid, and fasting blood glucose were also associated with clinical course to some degree. However, the history of alcohol intake, the presence of metabolic syndrome, blood pressure, and habitual physical exercise were not independent predictors for the development or regression of fatty liver. Our present data suggest that control of body weight in men and the percentage body fat in women are particularly important for the prevention or treatment of fatty liver.  相似文献   
106.
A 88 year old female with active rheumatoid arthritis treated by low dose of prednisolone and methotrexate was admitted to our hospital because of severe bilateral pulmonary infiltration and acute respiratory distress syndrome. On admission, she had consciousness disturbance and was intubated because of severe respiratory failure. We heard from her family of her habit she had taking a private whirlpool bath 2 or 3 times everyday. So, we suspected a Legionella pneumophila infection. We started intravenous erythromycin (EM) (1,500mg/day) and methylprednisolone pulse therapy (1,000mg x 3days) and full controlled mechanical ventilation supported with PEEP. Her respiratory failure was gradually improved and she was discharged on the 44 the hospital day. Legionella pneumophila (serogroup 6) was isolated in her sputum by B-CYE alpha culture. Legionella pneumophila (serogroup 6) was isolated in her private whirlpool bath too. Both samples revealed the same by genetic analysis with pulse field gel electrophoresis (PFGE). This is the first adult case of Legionella pneumophila pneumonia infected from a private whirlpool bath confirmed by genetic analysis. We should always suspect Legionella pneumonia as one of the severe community-acquired pneumonia, because Legionella pneumophila were frequently detected among various water sources including the private whirlpool bath.  相似文献   
107.
We report a 64-year-old woman with follicular thyroid cancer found by subacute bulbar palsy. Progressive bulbar palsy (PBP) was considered the most likely diagnosis, because no abnormal finding was detected on brain CT and blood test except for the decrease of free T4. An echogram of the thyroid revealed a small nodule which was shown to be class IIb by fine needle biopsy. However, 201Tl scintillation examination showed skull base metastasis. Follicular thyroid cancer sometimes seems to manifest as a distant metastasis with no clinically evident thyroid lesion. This case suggested the importance of a detailed survey for malignancy, when subacute bulbar palsy is seen.  相似文献   
108.
A 41-year-old man was referred to our hospital for further examination because of abnormal electrocardiography findings at a health-check examination. Transthoracic echocardiography showed left ventricular hypertrophy confined to the most distal portion of the left ventricle, which is a typical feature of apical hypertrophic cardiomyopathy. Ten years later, he was again admitted for the evaluation of chest pain. Echocardiography showed asymmetrical septal hypertrophy in addition to apical hypertrophy. These findings demonstrate morphologic evolution in hypertrophic cardiomyopathy from apical hypertrophy to asymmetrical septal hypertrophy.  相似文献   
109.
BACKGROUND/AIMS: Histamine H2 receptor antagonists are considered to exert their effects on gastric acid secretion more rapidly than proton pump antagonists. However, there are no reports concerning the direct interaction of a histamine H2 receptor antagonist with the human H2 receptor in terms of onset of action. This study aims to characterize how rapidly famotidine and ranitidine, the most widely used histamine H2 receptor antagonists, interact with the human histamine H2 receptor. METHODS: HEK293 cell lines, stably expressing human histamine H2 receptors, were obtained. The dose- and time-dependent effects of famotidine and ranitidine on [3H]-tiotidine binding and histamine-stimulated cAMP production were analyzed. RESULTS: Ranitidine inhibited both [3H]-tiotidine binding and histamine-stimulated cAMP production more promptly than did famotidine. Inhibition of histamine-stimulated cAMP production by Cmax doses of famotidine (20 mg p.o.) and ranitidine (150 mg p.o.) peaked by 15 and 2 min, respectively. [3H]-tiotidine binding was not saturated by 60 min at the famotidine Cmax, while the ranitidine Cmax had produced saturation by 15 min. CONCLUSION: Ranitidine inhibits the human histamine H2 receptor very rapidly.  相似文献   
110.
OBJECTIVE: Thioredoxin (TRX) is a redox regulatory protein that protects cells from various stresses. Angiotensin-converting enzyme (ACE) inhibitor was reported to enhance endogenous antioxidant enzyme activities. This study was carried out to investigate whether temocapril, a novel non-sulfhydryl-containing ACE inhibitor, reduces the severity of myocarditis via redox regulation mechanisms involving TRX. METHODS AND RESULTS: In normal rat myocytes in vitro and in vivo, Western blot showed that temocapril enhanced cytosolic redox regulatory protein TRX expression, but that neither mitochondrial TRX2 nor antioxidant enzymes, such as copper-zinc superoxide dismutase (Cu/Zn-SOD) or manganese superoxide dismutase (Mn-SOD) expression, was up-regulated by the preconditioning treatment. In rats with experimental autoimmune myocarditis (EAM), the severity of myocarditis and the protein carbonyl contents were less increased in temocapril treatment (10 mg/kg/day, orally) from day 1 to day 21, but not in temocapril treatment from day 15 to day 21. An immunohistochemical study showed that TRX stain was enhanced in infiltrating inflammatory cells and in damaged myocytes. Considering the characteristics of this model that myocardial inflammation begins around day 15 and increases until day 21, temocapril treatment for 3 weeks might be thought of as a preconditioning treatment. CONCLUSIONS: The results suggest that TRX and the redox state modified by TRX may play a crucial role in the pathophysiology of EAM. Temocapril ameliorates myocarditis associated with inducing TRX up-regulation in a preconditioning manner, although the mechanism of TRX up-regulation by temocapril remains to be elucidated.  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