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   1910篇
  免费   130篇
  国内免费   25篇
耳鼻咽喉   18篇
儿科学   47篇
妇产科学   8篇
基础医学   205篇
口腔科学   85篇
临床医学   181篇
内科学   497篇
皮肤病学   48篇
神经病学   144篇
特种医学   142篇
外科学   246篇
综合类   21篇
预防医学   75篇
眼科学   24篇
药学   130篇
中国医学   1篇
肿瘤学   193篇
  2024年   5篇
  2023年   43篇
  2022年   97篇
  2021年   192篇
  2020年   83篇
  2019年   93篇
  2018年   127篇
  2017年   74篇
  2016年   78篇
  2015年   68篇
  2014年   91篇
  2013年   88篇
  2012年   107篇
  2011年   99篇
  2010年   79篇
  2009年   61篇
  2008年   72篇
  2007年   88篇
  2006年   58篇
  2005年   56篇
  2004年   57篇
  2003年   38篇
  2002年   42篇
  2001年   21篇
  2000年   27篇
  1999年   27篇
  1998年   16篇
  1997年   5篇
  1996年   7篇
  1995年   7篇
  1994年   10篇
  1993年   7篇
  1992年   15篇
  1991年   15篇
  1990年   13篇
  1989年   16篇
  1988年   16篇
  1987年   10篇
  1986年   8篇
  1985年   7篇
  1984年   6篇
  1983年   9篇
  1977年   2篇
  1976年   3篇
  1974年   3篇
  1969年   4篇
  1968年   2篇
  1967年   2篇
  1966年   4篇
  1957年   1篇
排序方式: 共有2065条查询结果,搜索用时 31 毫秒
1.

Purpose

Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.

Methods and Materials

First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.

Results

The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.

Conclusions

The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target.  相似文献   
2.

Background

On April 1, 2016, the Ministerial ordinance was enforced, and musculoskeletal examination of the extremities was made mandatory. From 2008, the University of us started musculoskeletal direct examination. To expand the examination, from 2016, we started to use the marksheet-type questionnaire. This study aimed to report the results of a musculoskeletal examination and investigate the association between musculoskeletal examination and age/gender and reports the reliability of the collected questionnaire data.

Methods

Direct musculoskeletal examination was performed in K school by 7 orthopedic surgeons. A marksheet-type screening questionnaire was distributed to all the elementary and junior high school students in Tsukuba and Hitachiomiya cities. The rates of abnormal findings for scoliosis, standing flexion, full squatting with the heels on the floor, general joint laxity, and standing on one leg, torticollis, and flat feet were calculated. We compared the results of the questionnaire and direct examination and calculated sensitivity, specificity, and odds ratio.

Results

A total of 1844 students in K school had direct examination, and 22,494 questionnaires were able to correct in Tsukuba and Hitachiomiya cities. The rates of abnormal findings in direct examination/questionnaire in scoliosis, standing flexion, full squat, general joint laxity, standing on one leg, torticollis and flat foot were 18.7% (344/1842)/5.1% (1094/21441), 20.2% (372/1841)/26.6% (5817/22078), 6.2% (114/1832)/6.9% (1516/22101), 7.5% (1648/22252), 4.9% (1100/22077), 2.2% (31/1844)/1.2% (272/21687), and 12.5% (231/1842)/8.7% (1785/20871), respectively. Sensitivities of the questionnaire for scoliosis, stand flexion, full squatting, torticollis, and flat feet were 16.8% (53/316), 67.9% (250/368), 48.2% (55/114), 18.9% (7/37), and 32.2% (65/202), respectively.

Conclusion

We reported the result of musculoskeletal examination. Accuracy and reliability of this questionnaire were not satisfactory. To perform high quality musculoskeletal examinations, we will aim to increase the quality of screening methods.  相似文献   
3.
4.
Damus–Kaye–Stansel procedure is a useful method to relieve the systemic ventricular outflow tract obstruction in functionally univentricular heart. Regurgitation of pulmonary valve and recurrence of systemic ventricular outflow obstruction are the major concerns at the late phase of this procedure. Modification of original Damus–Kaye–Stansel procedure that can prevent the use of prosthetic materials is evaluated. The modified Damus–Kaye–Stansel procedure using aortic flap technique was performed in eight patients with functionally univentricular heart. Patients’ ages ranged from 3 to 28 months (mean 14 months). Follow-up period was 37 months as a mean (9–71 months), and the follow-up was complete. There was no operative mortality and no late death. In addition, there was no recurrence of systemic ventricular outflow tract obstruction throughout the follow-up period. Regurgitation of the pulmonary valve estimated by echocardiography at the latest follow-up was none to trivial in seven patients and mild in one. The modified Damus–Kaye–Stansel procedure using aortic flap technique is a safe, useful and reproducible technique to solve systemic ventricular outflow tract obstruction in functionally univentricular heart, and it can be an alternative for original technique or the so-called double-barrel modification.  相似文献   
5.
A 28-year-old man complaining of myiodesopsia was given a diagnosis of uveitis. Subsequently he complained facial nerve palsy and enlargement of parotid gland. Heerfordt's syndrome was diagnosed based on the results of several examinations. Facial nerve palsy, enlargement of the parotid gland and uveitis were improved by systemic corticosteroid therapy. At present he is receiving systemic corticosteroid therapy, but numbness in the mouth, thought to be the involvement of the trigeminal nerve, remains. Systemic corticosteroid therapy is usually effective for most cases with Heerford's syndrome. On the other hand, there are some cases with the prolonged peripheral nerve involvement despite systemic corticosteroid therapy, as seen in this case. If peripheral nerve involvement is prolonged, it is necessary to consider small-fibre neuropathy as one possible cause.  相似文献   
6.
Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO2) and nitrate (NO3) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO2 and NO3 levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region.  相似文献   
7.
It has been recently reported that acute immobilization stress almost completely suppresses the luteinizing hormone (LH) release induced by naloxone, a μ-opioid antagonist, in ovariectomized estrogen-primed rats. The present study examined the possible involvement of the pineal gland in the acute immobilization-related suppression of the naloxone-induced LH release. An intraventricular (ICV) injection of 15 μg naloxone produced an abrupt increase in circulating LH concentrations in non-stressed rats. The naloxone-induced LH release was completely eliminated when tested 60 min after the end of a 30 min session of acute immobilization. The same stress conditions did not affect LH-releasing hormone (LHRH)-induced LH release, suggesting that the stress-related suppression of the naloxone-induced LH release was a suprapituitary event. In chronically-pinealectomized rats, but not in sham-pinealectomized rats, naloxone injected 60 min after the end of the stress session evoked a significant increase in serum LH concentrations. However, naloxone injected ICV during the acute immobilization did not elicit LH release in either pinealectomized or sham-operated rats. Under non-stressed conditions, the LH secretory response to naloxone was similar in pinealectomized and sham-operated animals. The same stress (30 min immobilization) significantly increased pineal melatonin content as well as plasma melatonin concentrations in rats bearing intact pineal glands, indicating that stress actually affected the pineal function. These results provide evidence for a role of the pineal in the suppression of the LH response to naloxone after stress, but not during stress.  相似文献   
8.
Serum carcinoembryonic antigen (CEA), immunosuppressive acidic protein (IAP) and C-reactive protein (CRP) levels were measured in patients with adult T cell leukemia (ATL) in order to clarify their significance in this disease. Mean (+/- SD) serum CEA levels in 11 patients with acute ATL (3.1 +/- 1.3 ng/ml) and 7 patients with smoldering ATL (3.1 +/- 0.5 ng/ml) were significantly higher than in sera of 222 healthy controls (2.4 +/- 1.3 ng/ml). However, the levels in 7 patients with chronic ATL and healthy controls showed no differences. On the other hand, mean (+/- SD) serum IAP levels in patients with acute ATL (928 +/- 395 micrograms/ml), chronic ATL (487 +/- 125 micrograms/ml) and smoldering ATL (429 +/- 90 micrograms/ml) were significantly higher than in sera of healthy controls (359 +/- 103 micrograms/ml). However, the levels in patients with smoldering ATL and healthy controls showed no differences. Serum IAP levels in crisis in chronic and smoldering ATL were similar to those in patients with acute ATL. 85% of ATL patients with IAP levels above 500 micrograms/ml had CRP levels above 1+. Serum CEA, IAP and CRP levels were serially measured in a number of patients. Serum IAP and CRP levels reflected each patient's clinical course more than serum CEA levels. Overall the simultaneous measurements of serum CEA, IAP and CRP levels revealed a potential usefulness for determination of ATL subtype, and serum IAP and CRP levels may provide a way to evaluate the effectiveness of chemotherapy.  相似文献   
9.
10.
Insulin hypersensitivity in mice lacking the V1b vasopressin receptor   总被引:1,自引:0,他引:1  
We have reported that [Arg8]-vasopressin-stimulated insulin release is blunted in islet cells isolated from V1b receptor-deficient ( V1bR −/−) mice. In this study, we used V1bR −/− mice to examine the physiological role of the V1b receptor in regulating blood glucose levels in vivo , and we found that the fasting plasma glucose, insulin and glucagon levels were lower in V1bR −/− mice than in wild-type ( V1bR +/+) mice. Next, we evaluated glucose tolerance by performing an intraperitoneal glucose tolerance test (GTT). The plasma glucose and insulin levels during the GTT were lower in V1bR −/− mice than in V1bR +/+ mice. An insulin tolerance test (ITT) revealed that, after insulin administration, plasma glucose levels were lower in V1bR −/− mice than in V1bR +/+ mice. In addition, a hyperinsulinaemic–euglycaemic clamp study showed that the glucose infusion rate was increased in V1bR −/− mice, indicating that insulin sensitivity was enhanced at the in vivo level in V1bR −/− mice. Furthermore, we found that the V1b receptor was expressed in white adipose tissue and that insulin-stimulated phosphorylation of Akt as an important signaling molecule was increased in adipocytes isolated from V1bR −/− mice. Thus, the blockade of the V1b receptor could result, at least in part, in enhanced insulin sensitivity by altering insulin signalling in adipocytes.  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