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   2587篇
  免费   364篇
  国内免费   77篇
耳鼻咽喉   10篇
儿科学   16篇
妇产科学   2篇
基础医学   75篇
口腔科学   215篇
临床医学   211篇
内科学   144篇
皮肤病学   51篇
神经病学   25篇
特种医学   32篇
外科学   59篇
综合类   289篇
预防医学   102篇
眼科学   1072篇
药学   408篇
  3篇
中国医学   306篇
肿瘤学   8篇
  2024年   14篇
  2023年   77篇
  2022年   113篇
  2021年   182篇
  2020年   120篇
  2019年   127篇
  2018年   147篇
  2017年   170篇
  2016年   157篇
  2015年   130篇
  2014年   171篇
  2013年   251篇
  2012年   159篇
  2011年   147篇
  2010年   136篇
  2009年   125篇
  2008年   129篇
  2007年   111篇
  2006年   84篇
  2005年   71篇
  2004年   58篇
  2003年   42篇
  2002年   57篇
  2001年   44篇
  2000年   31篇
  1999年   24篇
  1998年   19篇
  1997年   17篇
  1996年   21篇
  1995年   9篇
  1994年   14篇
  1993年   5篇
  1992年   9篇
  1991年   5篇
  1990年   6篇
  1989年   9篇
  1988年   6篇
  1987年   7篇
  1986年   4篇
  1985年   2篇
  1984年   3篇
  1983年   2篇
  1982年   5篇
  1981年   4篇
  1980年   1篇
  1978年   1篇
  1977年   2篇
排序方式: 共有3028条查询结果,搜索用时 140 毫秒
101.
In order to create a worker-friendly environment for institutional foodservice, facilities operating with a dry kitchen system have been recommended. This study was designed to compare the work safety and work environment of foodservice between wet and dry kitchen systems. Data were obtained using questionnaires with a target group of 303 staff at 57 foodservice operations. Dry kitchen facilities were constructed after 2006, which had a higher construction cost and more finishing floors with anti-slip tiles, and in which employees more wore non-slip footwear than wet kitchen (76.7%). The kitchen temperature and muscular pain were the most frequently reported employees'' discomfort factors in the two systems, and, in the wet kitchen, "noise of kitchen" was also frequently reported as a discomfort. Dietitian and employees rated the less slippery and slip related incidents in dry kitchens than those of wet kitchen. Fryer area, ware-washing area, and plate waste table were the slippery areas and the causes were different between the functional areas. The risk for current leakage was rated significantly higher in wet kitchens by dietitians. In addition, the ware-washing area was found to be where employees felt the highest risk of electrical shock. Muscular pain (72.2%), arthritis (39.1%), hard-of-hearing (46.6%) and psychological stress (47.0%) were experienced by employees more than once a month, particularly in the wet kitchen. In conclusion, the dry kitchen system was found to be more efficient for food and work safety because of its superior design and well managed practices.  相似文献   
102.
Dry eye syndrome is a potential complication of botulinum toxin type-A injection (BTX-A) into the lateral canthal rhytids (crow''s feet). The early manifestations of this syndrome are subtle and are rarely reported to the treating physician. A guideline for early detection of dry-eye state is proposed, in order to avoid more troublesome adverse effects that may develop with repeated injections of BTX-A into the crow''s feet region. If suspected early, clinical manifestations remain minor and are reversible. However, delayed diagnosis may lead to troublesome and persistent symptoms. A novel and practical grading scale of lower eyelid snap-back and distraction tests is offered that helps in documenting patient''s clinical progress and in deciding when BTX-A injections should be delayed or discontinued.  相似文献   
103.
Abstract Exercise induced asthma is a common complaint and the prevalence appears to be increasing worldwide. Once confined to the research domain of university teaching hospitals, the study of EIA has extended into the school playground, defence force establishments and sports institutions. Standardized protocols have been developed to study EIA in the laboratory and in the field. A surrogate challenge using eucapnic or isocapnic hyperventilation with dry air is becoming popular because it has advantages over exercise, at least for adults. The stimulus that leads the airways to narrow is caused by the inhalation of dry air during hyperventilation and exercise, during which water is evaporated from the airways in order to condition the inspired air. The mechanism whereby the airways narrow is thought to be due to the dehydrating effects of water loss, particularly in relation to its potential to cause the airways to become hyperosmolar. Mast cell mediators such as histamine and the leucotrienes are probably involved in EIA because specific antagonists reduce severity. As a result of the osmotic theory of EIA, studies were carried out to determine whether subjects with EIA were sensitive to the effects of increasing airway osmolarity by inhalation of hyperosmolar aerosols of sodium chloride. A challenge protocol using an aerosol of 4.5% sodium chloride, generated from an ultrasonic nebulizer, has been used to identify persons with asthma and to assess response to drug therapy. There are many similarities between responses to exercise, hyperventilation and hypertonic saline in the physiological and biochemical responses and the responses to drugs. Challenge with hypertonic saline is easier and cheaper to use because expensive equipment and a source of dry air is not required as with exercise or hyperventilation. The ability to obtain a dose-response curve rather than a single response and the ability to collect inflammatory cells at the same time make challenge with hypertonic saline an attractive technique to study patients suspected of having asthma.  相似文献   
104.
105.
Pulmonary diffusing capacity for carbon monoxide (DLCO) is a valuable pulmonary function test to evaluate the gas exchange capacity of the lungs. Generally, DLCO values are significantly lower in patients with chronic obstructive pulmonary disease (COPD), particularly in those with a predominantly emphysema phenotype. However, it is extremely rare that DLCO values cannot be obtained for reasons other than technical errors. Herein, we report two patients with COPD in whom DLCO values were undetectable without prolonging the breath-holding time for the test. We discuss possible mechanisms for these peculiar findings.  相似文献   
106.
107.
Prosthetic management of partial edentulism can be challenging with the presence of limited interocclusal space. The extrusion of opposing teeth combined with the alveolar extrusion of the edentulous areas reduces the space needed for fabricating a removable or fixed prosthesis when edentulous areas are present in the maxilla. This clinical report describes the treatment provided to a patient who presented with a limited interocclusal space on the posterior right quadrant. Before prosthetic rehabilitation, mandibular right posterior teeth were intruded, and the maxillary right posterior alveolar crest was reduced by alveoloplasty. After gaining adequate space, prosthetic rehabilitation was completed with a maxillary removable partial denture. During the 2‐year follow‐up period, the patient's chewing functions and physical appearance improved, and no complications occurred.  相似文献   
108.
Objective:To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite.Materials and Methods:This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test.Results:The mean treatment observation time was 1.31 years (SD  =  2.03). The maxillary first molars (P  =  0.0026) and second molars (P  =  0.039) were intruded. However, the mandibular first molars (P  =  0.0004) and second molars (P  =  0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P  =  0.025 and P  =  0.044, respectively). The mandibular plane angle decreased (P  =  0.036), lower facial height decreased (P  =  0.002), and the occlusal plane angle increased (P  =  0.009). The overbite increased (P < .0001). The ANB angle decreased (P < .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes.Conclusions:Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults.  相似文献   
109.
This case report describes the treatment of a patient with temporomandibular disorder (TMD) and skeletal open bite. First, the patient was treated with a stabilization splint to stabilize the condyles in centric relation and to alleviate TMD signs and symptoms. After making a definitive diagnosis from postsplint records, orthodontic treatment was initiated. Titanium miniplates were placed at bilateral zygomatic buttresses and used as orthodontic anchorage for molar intrusion and distalization. The treatment was completed after 30 months. Satisfactory appearance and function were achieved for this patient.  相似文献   
110.
When selecting treatment for traumatically intruded teeth, various factors should be evaluated including the degree of intrusion, pulp vitality, patient's age and maturity of the tooth. Treatment options consist of surgical repositioning, orthodontic extrusion and spontaneous re‐eruption. This study describes a case of a 22‐year‐old male with traumatically intruded maxillary canine and first premolar that was treated comprehensively by an orthodontist, endodontist and prosthodontist two months after injury.  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