首页 | 官方网站   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   2933篇
  免费   193篇
  国内免费   22篇
医药卫生   3148篇
  2023年   21篇
  2022年   35篇
  2021年   51篇
  2020年   37篇
  2019年   54篇
  2018年   68篇
  2017年   58篇
  2016年   81篇
  2015年   69篇
  2014年   107篇
  2013年   108篇
  2012年   178篇
  2011年   178篇
  2010年   95篇
  2009年   87篇
  2008年   173篇
  2007年   172篇
  2006年   170篇
  2005年   157篇
  2004年   160篇
  2003年   134篇
  2002年   116篇
  2001年   68篇
  2000年   84篇
  1999年   55篇
  1998年   32篇
  1997年   28篇
  1996年   28篇
  1995年   30篇
  1994年   20篇
  1993年   12篇
  1992年   45篇
  1991年   45篇
  1990年   35篇
  1989年   35篇
  1988年   26篇
  1987年   36篇
  1986年   44篇
  1985年   39篇
  1984年   16篇
  1983年   27篇
  1982年   13篇
  1981年   10篇
  1980年   9篇
  1979年   15篇
  1978年   13篇
  1977年   11篇
  1974年   9篇
  1973年   9篇
  1972年   9篇
排序方式: 共有3148条查询结果,搜索用时 15 毫秒
1.
2.
Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients.  相似文献   
3.
Treatment of traumatically intruded teeth is based largely on empirical clinical experience rather than on scientific data. The aim of this qualitative meta-analysis was to provide an evidence base to evaluate the orthodontic repositioning approach. In a MEDLINE search of the literature in English, 14 reported patients involving 22 teeth were found to have been treated by this modality. Additionally, 3 new patients, involving 9 intruded teeth and presented herein, were combined to form a total study sample of 17 subjects (7 girls, 10 boys, aged 8.9 +/- 1.2 years). Orthodontic extrusive forces were applied in the immediate posttrauma period (up to 3 months), with a variety of orthodontic appliances. Repositioning was achieved for 90.3% of the affected teeth but failed in 9.7% because of inflammatory resorption (2 teeth) or a misdiagnosis of root fracture (1 tooth). Early complications included loss of pulp vitality and external root resorption. All intruded teeth with closed root apices lost their vitality regardless of the degree of intrusion, whereas among those with incomplete apices, 45.5% that had been moderately intruded remained vital. External resorption was encountered in 54.8% of the teeth. Loss of marginal bone support was rarely encountered. Late complications included inflammatory root resorption in teeth with closed apices, in which endodontic treatment was not initially performed, and obliteration of the pulp tissue in teeth that remained vital. The results show that this method is superior to other treatment alternatives.  相似文献   
4.
Over the last two decades there has been accumulating evidence that both psychosocial and pharmacological treatment interventions can effect change in substance-misusing adults. Thus, treatment interventions implemented for young people with substance problems largely draw on the adult addiction experience and that of child and adolescent psychiatry and psychology. As young people with problematic drug use have different treatment needs, and require different interventions and services to those of adults, results of adult studies cannot necessarily be directly extrapolated to young people.

Over the last five years evidence has been rapidly mounting that treatment may potentially work in young people, but as yet it is not as extensive as that for adults. The interventions that appear most fruitful are those based on learning theory, e.g. cognitive behavioural therapy and family therapy. Outcome studies in young people demonstrate substantial variability in substance use and misuse following treatment. From the UK perspective, the evidence is almost entirely USA based, and these evaluations of non-UK treatment programmes for young people cannot be simply transferred or transported to UK healthcare settings. This has significant implications for practice and policy.

At this stage, 'guidelines' or 'guidance' that is available is either not directed at young people and/or is largely gleaned from the USA literature. In addition, it does not adequately capture the complexity of cases at front-line specialist settings. The management of young substance misusers in the UK is, in the main, 'beyond guidelines and guidance'.

The restricted treatment service network for young people in the UK makes the potential for undertaking studies on treatment effectiveness extremely limited, but because there is evidence of a growing number of young people requiring treatment, such specialist drug services require evaluation. Serious consideration of the establishment and funding of evaluation of treatment interventions to be delivered to young substance misusers in the UK is urgently needed.  相似文献   
5.
T Takemoto  H Yanai 《Gan no rinsho》1986,32(10):1077-1081
It is obvious that surgical resection is a superior therapy for gastric cancer. In this sense, endoscopic therapy could be regarded as an orphan in this field. However, in the combination of endoscopic therapy and ultrasonic endoscopy, endoscopic therapy for gastric cancer should be acknowledged to be equal to surgical therapy. We have treated early gastric cancer by means of endoscopical photocoagulation using a Nd-YAG laser, particularly in inoperable cases due to other complication or old age. Forty-seven lesions found in 41 patients have so far been photocoagulation and followed up. By this treatment, cancer cells disappeared in 42 out of 47 lesions, although 2 cases died of other diseases and recurrence was experienced in 3 cases. In addition to photocoagulation therapy using a laser, we have recently developed a large-biopsy technique called strip biopsy in order to get sufficient tissue for diagnosis in comparison with bite biopsy. By this method, we are able to resect the full thickness of the mucosa including the submucosal layer up to a size of about 4 cm, without any severe complication such as hemorrhage and perforation. We succeeded in resecting the early gastric cancer in 34 lesion in 31 patients. The combination therapy of endoscopical photocoagulation and strip biopsy seems to be reasonable for the therapy of early gastric cancer.  相似文献   
6.
Neurofibromatosis type 1 (NF 1) is a syndrome with a predisposition for benign and malignant tumor development. Of the malignant neoplasms, osteogenic sarcomas are rare but have been described. There are some reports of patients with neurofibromatosis type 1 with a parathyroid adenoma and hyperparathyroidism. Also, there are studies that imply that the parathyroid hormone plays a role in the regulation and modulation of oseogenic sarcomas in vitro. We report about a 50-year-old female suffering from neurofibromatosis type 1, with a 3-year documented history of untreated hyperparathyroidism and a parathyroid adenoma. The patient developed a mandibular osteogenic sarcoma. To our knowledge, this is the first reported case occurring in the mandible. The unusual tumor site for a patient with neurofibromatosis type 1, the conjugation with hyperparathyroidism and the rapid growth of an osteogenic sarcoma are intriguing.  相似文献   
7.
Chondroid syringoma of the vulva is an extremely rare tumor. Of the previously reported cases, only one was clinically malignant. The authors describe a case of chondroid syringoma of the right labium majus from which arose a papillary adenocarcinoma. A right inguinal lymph node was replaced with metastatic adenocarcinoma.  相似文献   
8.
9.
The purpose of this study was to clarify the significance of immunohistological staining for PCNA/cyclin in human colorectal lesions. Our results: The PCNA-positive cells existed at the bottom of colonic tubuli in the normal and hyperplastic conditions. In the neoplastic lesions, however, the positive cells were existed at the relatively surface of the mucosa (chi 2: P less than 0.01) and distributed irregularly from the bottom to the top of carcinoma tissue. These results suggested that immunohistological staining for PCNA would specifically detect the cell proliferation and be beneficial for practical use and clinical application of the diagnosis of the colorectal lesions.  相似文献   
10.
Occasionally, a dental patient presents his/her dentist with a history of hypersensitivity to local anesthetic agents. The symptoms may include immediate reactions to the injection procedure (dizziness, shortness of breath, tachycardia, etc), or delayed reactions to the anesthetic (swelling, urticaria, etc). Although the true incidence of local anesthetic allergy is low, such a history often involves the patient's anxiety regarding the use of the drug in question, and the dentist's apprehension to treat the "problematic" patient. In such cases, hypnosis can play a major role in controlling pain and the associated distress. In the present article, the method concerning the implementation of hypnosis to induce local anesthesia is described and illustrated through case demonstrations.  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-23

京公网安备 11010802026262号