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   12218篇
  免费   568篇
  国内免费   78篇
耳鼻咽喉   127篇
儿科学   187篇
妇产科学   95篇
基础医学   1397篇
口腔科学   286篇
临床医学   817篇
内科学   3571篇
皮肤病学   347篇
神经病学   725篇
特种医学   487篇
外科学   2026篇
综合类   35篇
一般理论   1篇
预防医学   266篇
眼科学   146篇
药学   805篇
中国医学   29篇
肿瘤学   1517篇
  2023年   96篇
  2022年   240篇
  2021年   372篇
  2020年   185篇
  2019年   246篇
  2018年   297篇
  2017年   260篇
  2016年   308篇
  2015年   292篇
  2014年   376篇
  2013年   449篇
  2012年   824篇
  2011年   862篇
  2010年   523篇
  2009年   416篇
  2008年   724篇
  2007年   753篇
  2006年   722篇
  2005年   677篇
  2004年   652篇
  2003年   613篇
  2002年   616篇
  2001年   195篇
  2000年   206篇
  1999年   175篇
  1998年   125篇
  1997年   102篇
  1996年   62篇
  1995年   76篇
  1994年   68篇
  1993年   63篇
  1992年   132篇
  1991年   114篇
  1990年   87篇
  1989年   105篇
  1988年   99篇
  1987年   60篇
  1986年   80篇
  1985年   80篇
  1984年   61篇
  1983年   46篇
  1982年   30篇
  1981年   24篇
  1980年   23篇
  1979年   47篇
  1977年   24篇
  1975年   27篇
  1973年   23篇
  1970年   23篇
  1969年   25篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
1.
2.
Anthocyanins, which are responsible for a variety of bright colors (including red, blue, and purple) in fruits, vegetables, and flowers, are consumed as dietary polyphenols. Anthocyanin-containing fruits are thought to decrease coronary heart disease and are used in anti-diabetic preparations. Diabetes is associated with a variety of cardiovascular complications that may be mediated by endothelial dysfunction, and so this study was designed mainly to characterize the influence of a synthesized anthocyanidin derivative (HK-008) over acetylcholine (ACh)-induced relaxation in mesenteric arterial beds isolated from rats. In a glucose-tolerance test in intact rats, HK-008 (30 mg/kg) reduced the glucose level as effectively as the same dose of glibenclamide. The aortic relaxation induced by pinacidil (an ATP-sensitive potassium channel opener) was greatly inhibited by glibenclamide (10 microM), and also significantly inhibited by HK-008 (10 microM). Interestingly, the ACh-induced relaxation in the perfused, preconstricted mesenteric arterial bed was significantly enhanced by HK-008 (10 microM), and this enhancement was significantly attenuated by indomethacin (10 microM). The ACh-induced mesenteric relaxation was impaired by an increase in oxidative stress, viz. superoxide-generating treatment [xanthine oxidase (XO; 0.1 U/ml) plus hypoxanthine (HX; 10 microM)]. However, this impairment was strongly suppressed by HK-008 (10 microM). These results suggest that HK-008 increases endothelium-induced relaxation by suppressing oxidative stress or modulating prostanoids signaling. This compound may therefore be useful against certain cardiovascular disorders.  相似文献   
3.
Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 microg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life.  相似文献   
4.
We describe a 53-year-old man with herpes simplex virus (HSV) brainstem encephalitis diagnosed based by positive HSV immunoglobulin M antibodies from cerebrospinal fluid. The MRI findings of this case had three unique features. First, the lesions were symmetrical. Second, the lesions may have been associated with reactivation of HSV infection in the region of the trigeminal nerve. Third, diffusion-weighted and apparent diffusion coefficient (ADC) imaging, conducted for the first time on an HSV brainstem encephalitis case, suggested that the lesions were associated with vasogenic edema.  相似文献   
5.
6.
We describe a case of 41-year-old Japanese man with Crohn's ileocolitis and cytomegalovirus infection, confirmed by histology of ileal ulcers. Although his colonoscopic and radiological features resembled those of intestinal tuberculosis, granulomas of typical Crohn's disease were evident on histology of biopsy specimens taken from the duodenum and colon. The lesions remain unchanged even after 1.5 years by oral administration of salazosulphapyridine 3g daily.  相似文献   
7.
The second derivative of the finger photoplethysmogram (SDPTG) has been used as a non-invasive examination for arterial stiffness. The present study sought to elucidate independent determinants of the SDPTG among various cardiovascular risk factors in middle-aged Japanese men. The SDPTG was obtained from the cuticle of the left-hand forefinger in 973 male workers (mean age: 44+/-6 years) during a medical checkup at a company. The SDPTG indices (b/a and d/a) were calculated from the height of the wave components. Multiple logistic regression analyses revealed that the independent determinants of an increased b/a (highest quartile of the b/a) were age (odds ratio [OR]: 1.12 per 1-year increase, 95% confidence interval [CI]: 1.09-1.15), hypertension (OR: 1.65, 95% CI: 1.03-2.65), dyslipidemia (OR: 1.51, 95% CI: 1.09-2.09), impaired fasting glucose/diabetes mellitus (OR: 2.43, 95% CI: 1.16-5.07), and a lack of regular exercise (OR: 2.00, 95% CI: 1.29-3.08). Similarly, independent determinants of a decreased d/a (lowest quartile of the d/a) were age (OR: 1.11 per 1-year increase, 95% CI: 1.08-1.14), hypertension (OR: 3.44, 95% CI: 2.20-5.38), and alcohol intake 6 or 7 days per week (OR: 2.70, 95% CI: 1.80-4.06). No independent association was observed between the SDPTG indices and blood leukocyte count or serum C-reactive protein levels. In conclusion, the SDPTG indices reflect arterial properties affected by several cardiovascular risk factors in middle-aged Japanese men. The association between inflammation and the SDPTG should be evaluated in further studies.  相似文献   
8.
OBJECTIVE: To evaluate the initial results of brachytherapy for prostate cancer with permanent iodine-125 implant in Japan. METHODS: The results obtained with brachytherapy in the initial 100 Japanese patients treated at Nagano Municipal Hospital were reviewed. Patients with a prostate-specific antigen (PSA) level of less than 10 ng/mL and a Gleason's scores of 5, 6, 3 + 4 were classified as having a low risk of recurrence. Patients with a PSA level of 10-20 ng/mL and/or a Gleason's score of 4 + 3 were classified as having an intermediate risk for recurrence. Seventy-eight of the low-risk patients and 19 of the intermediate-risk patients were treated by seed implants alone, or seed implants combined with preceding external radiation, respectively. A total of 53 patients received neoadjuvant hormone therapy. The efficacy and morbidity of brachytherapy were investigated using the serum PSA, International Prostate Symptom Score, quality of life score and uroflowmetry data. RESULTS: The average V100 and D90 obtained by post-implant dosimetry was 94.3 and 113.7%, respectively. Serum PSA decreased gradually after treatment, although it had still not reached a nadir after 1 year. There was little difference of the PSA level between the patients with and without neoadjuvant hormone therapy even at 1 year after seed implantation. There were no PSA biochemical failure or clinical recurrence during the follow-up period. Voiding symptoms worsened until 3 months after treatment, and then gradually improved. Acute urinary retention occurred transiently in one patient (1%). Rectal bleeding and severe diarrhea did not occur. CONCLUSION: Brachytherapy is a feasible and effective option for the treatment of prostate cancer in Japanese men. Brachytherapy may have a different effect in Japanese patients with respect to voiding symptoms. Urinary retention was rare, but voiding symptoms were persistent in Japanese patients. Neoadjuvant hormone therapy deserves investigation to determine whether it can achieve better results, especially in patients with an intermediate risk.  相似文献   
9.
Abstract:   A 66-year-old man was referred to our hospital with chest discomfort and shortness of breath. Seven months previously he had undergone a laparoscopic left nephroureterectomy for a left renal pelvic tumor and was given two cycles of adjuvant chemotherapy (methotrexate, epirubicin and cisplatin). Echocardiogram showed an 8-mm sized mass extending from the right atrium into the right ventricle. On computed tomography, multiple lung tumors, as well as the right atrial and ventricular mass, were seen. The patient died of acute heart failure caused by right ventricular outflow obstruction. On autopsy, a right atrial and ventricular metastasis of the initial transitional cell carcinoma was found. The patient's cause of death was acute heart failure as a result of cardiac metastasis of his initial renal pelvic carcinoma.  相似文献   
10.
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