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   7157篇
  免费   336篇
  国内免费   76篇
耳鼻咽喉   28篇
儿科学   142篇
妇产科学   133篇
基础医学   1073篇
口腔科学   148篇
临床医学   426篇
内科学   1748篇
皮肤病学   252篇
神经病学   601篇
特种医学   250篇
外科学   1105篇
综合类   23篇
预防医学   178篇
眼科学   73篇
药学   516篇
中国医学   18篇
肿瘤学   855篇
  2023年   29篇
  2022年   94篇
  2021年   148篇
  2020年   76篇
  2019年   102篇
  2018年   149篇
  2017年   158篇
  2016年   169篇
  2015年   170篇
  2014年   244篇
  2013年   280篇
  2012年   468篇
  2011年   518篇
  2010年   305篇
  2009年   243篇
  2008年   427篇
  2007年   502篇
  2006年   490篇
  2005年   489篇
  2004年   479篇
  2003年   502篇
  2002年   474篇
  2001年   74篇
  2000年   64篇
  1999年   91篇
  1998年   125篇
  1997年   81篇
  1996年   69篇
  1995年   73篇
  1994年   65篇
  1993年   53篇
  1992年   44篇
  1991年   39篇
  1990年   36篇
  1989年   41篇
  1988年   19篇
  1987年   23篇
  1986年   11篇
  1985年   16篇
  1984年   13篇
  1983年   10篇
  1982年   18篇
  1981年   9篇
  1980年   12篇
  1979年   14篇
  1978年   8篇
  1977年   7篇
  1976年   6篇
  1973年   7篇
  1969年   5篇
排序方式: 共有7569条查询结果,搜索用时 15 毫秒
121.
Background: Bone marrow-derived cells (BMCs) have abilities of cell migration and differentiation into tissues/organs in the body and related with the differentiation of teeth or periodontal tissue including fibroblasts. Then, we examined the effect of orthodontic mechanical stress to the transplanted BMC migration into periodontal tissues using BMC transplantation model.Material and Method: BMC from green fluorescence protein (GFP) transgenic mice were transplanted into 8-week-old female C57BL/6 immunocompromised recipient mice, which had undergone 10 Gy of lethal whole-body-irradiation. Five mice as experimental group were received orthodontic mechanical stress using separator between first molar (M1) and second molar (M2) 1 time per week for 5 weeks and 5 mice as control group were not received mechanical stress. The maxilla with M1 and M2 was removed and was immunohistochemically analyzed using a Dako Envision + Kit-K4006 and a primary anti-GFP-polyclonal rabbit antibody. Immunohistochemically stained was defined as positive area and the pixel number of positive area in the periodontal tissue was compared with the previously calculated total pixel number of the periodontal tissue.Results: The immunohistochemistry revealed that GFP positive cells were detected in the periodontal tissues, both in the experimental and control specimens. The ratio of pixel number in the examination group showed 5.77 ± 3.24 % (mean ± SD); and that in the control group, 0.71±0.45 % (mean ± SD). The examination group was significantly greater than that of control group (Mann-Whitney U test: p<0.001).Conclusion: These results suggest that orthodontic mechanical stress accelerates transplanted BMC migration into periodontal tissues.  相似文献   
122.
Purpose: Current guidelines recommend α1-adrenoreceptor blockers (A1Bs) for treating lower urinary tract symptoms suggestive of benign prostatic hyperplasia, but their adverse effects can be problematic. In this study, reports submitted to the US Food and Drug Administration Adverse Event Reporting System (FAERS) between 1997 and 2011 were reviewed to assess the safety profiles of A1Bs.Methods: After deleting duplicated submissions and revising arbitrary drug names, reports involving A1Bs for male patients were analyzed. Data mining algorisms were used for the quantitative detection of signals, where a signal represents an association between a drug and an adverse event or a drug-associated adverse event, including the proportional reporting ratio, reporting odds ratio, information component given by a Bayesian confidence propagation neural network, and empirical Bayes geometric mean.Results: The total number of reports used was 1,260,182. Signal scores suggested the associations of alfuzosin, doxazosin, tamsulosin, and terazosin with dizziness/vertigo, orthostatic hypotension, erectile dysfunction, ejaculation dysfunction (EjD), thirst/dry mouth, and constipation; however, reports on naftopidil, silodosin, and urapidil were not enough to compare with the other 4 A1Bs. Signal scores for EjD were higher for tamsulosin, and those for dizziness/vertigo were lower for doxazosin than for the other 3 drugs.Conclusions: Tamsulosin-associated EjD, which was found in clinical studies, was reproduced in this analysis with markedly higher signal scores, and these results strongly suggest the necessity of well-organized clinical studies on A1B-associated adverse events.  相似文献   
123.
124.
Laparoscopic appendectomy is now widely practiced for the treatment of acute appendicitis. As result of increased demand for minimally invasive surgery, single-incision access was introduced and is being performed in various abdominal surgeries. Conventional laparoscopic appendectomy (LA) is gradually being performed in pregnant women. A 33-year-old woman was referred to our department at 39 weeks and 1 day of gestation due to abdominal pain. She was aware of her gastroepiploic pain even after the delivery. Though it was past 2 days, she was not recovering from right lower abdominal pain, so she was transferred to the Department of Gynecology at our hospital on the same day. Although an antibiotic was administered, the right abdominal pain did not improve, and she was referred to our department from the Department of Gynecology. We performed single-port LA (SP-LA). The total operation time was 63 minutes, and the estimated blood loss was 0 mL. She was discharged with no complications on postoperative day 7. We report our initial experience with single-port LA (SP-LA) using the glove technique for treatment of acute appendicitis in a postpartum woman. SP-LA using the glove technique was performed successfully during the puerperium without prolongation of operation time. This approach is less invasive, offers a much better cosmetic result than with conventional methods, and can be performed safely and at low cost.Key words: PLA (single-port laparoscopic appendectomy), PuerperiumThe advantages of laparoscopic appendectomy (LA) over open appendectomy (OA) are widely known and include decreased pain, shorter convalescence, and earlier return to work. Especially, LA is advantageous for treating acute appendicitis in pregnant women. Because the appendix of a pregnant woman is shifted from its normal position, OA may leave a larger operative scar than normal. In recent years, efforts of laparoscopic surgeons have resulted in a reduction in both the diameter of the access ports and the number of ports needed.1 In addition, natural orifice transluminal endoscopic surgery (NOTES) is being developed as another form of minimally invasive surgery.2 As a part of this process, the single-incision laparoscopic surgery (SILS) technique is presently being developed for various laparoscopic surgeries.3 SILS is a virtually scarless technique in which the single-port access site is hidden in the umbilicus. We think that the primary advantage of single-port laparoscopic appendectomy (SP-LA) is the superior cosmetic result compared with multi-port access LA. We report a very rare case in which SP-LA was performed to treat acute appendicitis during the puerperium. This approach is less invasive, offers a much better cosmetic result than with conventional methods, and can be performed safely and at low cost.  相似文献   
125.
126.
BACKGROUND: Differentiation between benign and malignant nonfunctioning islet cell tumors of the pancreas before surgery is often difficult. The roles of EUS and ERCP were evaluated in the differential diagnosis of these tumors. METHODS: Seven patients with histologically confirmed nonfunctioning islet cell tumors (4 benign, 3 malignant) underwent EUS and ERCP. OBSERVATIONS: EUS demonstrated a homogeneous hypoechoic mass or a hypoechoic mass with a regular central echogenic area in the 4 cases of benign tumor, and a hypoechoic mass with an irregular central echogenic area in all 3 cases of malignant tumor. The irregular central echogenic area corresponded to severe hemorrhage, necrosis, or fibrosis with hyalinosis (hyaline degeneration) on pathologic examination. ERCP demonstrated displacement or complete obstruction (because of ductal invasion) of the main pancreatic duct in 2 patients with malignant tumors and no abnormalities in the other 5 cases. CONCLUSIONS: In patients with nonfunctioning islet cell tumors, a hypoechoic mass with an irregular central echogenic area on EUS or complete obstruction of the main pancreatic duct on ERCP suggests malignancy.  相似文献   
127.
BACKGROUND: The extent to which atrial fibrillation (AF) contributes to mortality in the Japanese general population has not been clarified. METHODS AND RESULTS: A randomly sampled general population from all over Japan (4,154 men, 5,329 women; age > or =30 years) was enrolled. Single electrocardiogram recordings were taken in the baseline survey. Stroke death, cardiovascular deaths and all-cause deaths during the subsequent 19 years were analyzed by the presence of AF at baseline. Cox's regression analysis was carried out to estimate the hazard ratios (HRs) of each cause of death attributable to AF after adjusting for other risk factors. Prevalence of AF was 0.64% in the study. The observed person-years were 162,980 among persons without AF and 699 among persons with AF. There were 1,919 deaths. Multivariate adjusted HRs for stroke death, cardiovascular death and all-cause death were 2.69, 2.76 and 1.88, respectively (p<0.05). These HRs were 14.7, 9.63 and 4.00 among persons aged 64 years or younger (p<0.05). CONCLUSION: AF affects stroke mortality, cardiovascular mortality and all-cause mortality in the Japanese general population. Careful attention should be paid to persons with AF in order to prevent future cardiovascular events.  相似文献   
128.
A 51-year-old Japanese woman with a solitary liver metastasis originating from a carcinoma of the ampulla of Vater was successfully treated by partial hepatectomy 19 months after curative pancreatoduodenectomy with lymphadenectomy. Histologic examination revealed a stage III well-differentiated tubular adenocarcinoma (pT2, pN1, and pM0). Postoperative serum concentrations of carcinoembryonic antigen increased exponentially to 133 ng/mL. The carcinoembryonic antigen doubling time was 63 days. Computed tomography and ultrasonography of the abdomen showed a solitary metastasis in segment VI of the liver. Since neither local recurrences nor other distant metastases were detected, the patient underwent partial hepatectomy. Histologic study confirmed the presence of a metastatic liver tumor from the ampullary carcinoma. The carcinoembryonic antigen levels returned to normal immediately after the partial hepatectomy. She was well without signs of recurrence 18 months after partial hepatectomy.  相似文献   
129.
Recently, the need for sedation in gastrointestinal endoscopy has been increasing. However, the National Health Insurance Drug Price list in Japan does not include any drug specifically used for the sedation. Although benzodiazepines are the main medication, their use in cases of gastrointestinal endoscopy has not been approved. This has led the Japan Gastrointestinal Endoscopy Society to develop the first set of guidelines for sedation in gastrointestinal endoscopy on the basis of evidence‐based medicine in collaboration with the Japanese Society for Anesthesiologists. The present guidelines comprise 14 statements, five of which were judged to be valid on the highest evidence level and three on the second highest level. The guidelines are not intended to strongly recommend the use of sedation for gastrointestinal endoscopy, but rather to indicate the policy as to the choice of appropriate procedures when such sedation is deemed necessary. In clinical practice, the final decision as to the use of sedation should be made by physicians considering patient willingness and physical condition.  相似文献   
130.
A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing.  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