全文获取类型
收费全文 | 5575篇 |
免费 | 490篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 382篇 |
妇产科学 | 123篇 |
基础医学 | 874篇 |
口腔科学 | 438篇 |
临床医学 | 427篇 |
内科学 | 1448篇 |
皮肤病学 | 46篇 |
神经病学 | 36篇 |
特种医学 | 180篇 |
外国民族医学 | 3篇 |
外科学 | 785篇 |
综合类 | 409篇 |
现状与发展 | 2篇 |
预防医学 | 181篇 |
眼科学 | 77篇 |
药学 | 204篇 |
中国医学 | 32篇 |
肿瘤学 | 382篇 |
出版年
2024年 | 16篇 |
2023年 | 66篇 |
2022年 | 135篇 |
2021年 | 181篇 |
2020年 | 212篇 |
2019年 | 245篇 |
2018年 | 224篇 |
2017年 | 213篇 |
2016年 | 207篇 |
2015年 | 204篇 |
2014年 | 288篇 |
2013年 | 378篇 |
2012年 | 223篇 |
2011年 | 264篇 |
2010年 | 254篇 |
2009年 | 263篇 |
2008年 | 257篇 |
2007年 | 271篇 |
2006年 | 269篇 |
2005年 | 227篇 |
2004年 | 200篇 |
2003年 | 158篇 |
2002年 | 147篇 |
2001年 | 146篇 |
2000年 | 104篇 |
1999年 | 101篇 |
1998年 | 108篇 |
1997年 | 111篇 |
1996年 | 105篇 |
1995年 | 66篇 |
1994年 | 65篇 |
1993年 | 55篇 |
1992年 | 41篇 |
1991年 | 48篇 |
1990年 | 37篇 |
1989年 | 24篇 |
1988年 | 33篇 |
1987年 | 30篇 |
1986年 | 35篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 4篇 |
1973年 | 3篇 |
排序方式: 共有6157条查询结果,搜索用时 0 毫秒
991.
Hans-Joachim Mentzel Dirk Schramm Susanna Vogt Annegret Reuter Thomas Mentzel Werner A. Kaiser 《Journal of clinical ultrasound : JCU》1998,26(6):320-322
We report the case of a male newborn infant with an intra-abdominal cavernous lymphangioma that produced acute abdominal symptoms. Sonography showed a cystic mass with thin septations, which caused intestinal obstruction and stenosis of the iliac artery. The histologic findings after surgical resection reflected the sonographic appearance of the mass. The differential diagnosis of cystic abdominal lesions is discussed. Sonography is the preferred method of diagnosis. © 1998 John Wiley & Sons, Inc. J Clin Ultrasound 26:320–322, 1998. 相似文献
992.
C. Granata C. Gambini T. Balducci P. Toma A. Michelazzi M. Conte V. Jasonni 《Pediatric pulmonology》1998,25(1):62-66
A type I congenital cystic adenomatoid malformation (CCAM) in the left lower lobe was removed from a 11-year-old boy with a 3-month history of recurrent pneumonia. As incidental finding, a bronchioloalveolar carcinoma (BAC) was found in the lung parenchyma adjacent to the cyst. A left lower lobectomy was performed. At 18 months after surgery the patient is well and free of neoplastic disease. To the best of our knowledge, this association has not been reported previously in a pediatric patient. Malignancies complicating CCAM are rarely seen, but have been reported in adults. Including our case, eight cases of BAC and five cases of rhabdomyosarcoma (RMS) in association with CCAM have been reported so far. As CCAM can host metaplastic mucous cells, primitive mesenchymal cells and differentiated but poorly organized striated muscle fibers, it has been proposed that CCAM may act as a predisposing condition for oncogenesis. Our experience adds further support that CCAM can act as a premalignant lesion. Previous reports of both BAC and RMS in asymptomatic CCAM suggest prompt resection shortly after diagnosis. Pediatr. Pulmonol. 1998; 25:62–66. © 1998 Wiley-Liss, Inc. 相似文献
993.
This placebo-controlled study was designed to confirm a previously performed open label study that showed significant improvement in spirometry on maintenance therapy with albuterol for 1 year. In a double-blind, cross-over trial, albuterol (by metered dose inhaler) 180 μg b.i.d. or placebo were given for 6 months each. Spirometry was monitored at the start, and 3 and 6 months following initiation of each arm of the study. Peak expiratory flow rate (PEFR) was measured twice daily at home before and after study drug administration. Only patients with clinically detectable lung disease were enrolled. Twenty-one patients finished the study. All spirometric tests showed a significant improvement from start to end of the 6 month treatment with albuterol; there was no significant change on placebo. Forced vital capacity improved by 8.2% and forced expiratory volume in 1 s by 12.1% on albuterol therapy. Nevertheless, there was no significant difference between change on albuterol and change on placebo. Home measurements of PEFR showed a significant improvement of 4.7% on albuterol and a non-significant change of 2.0% on placebo from the first to the last week of treatment. None of the long-term improvements (spirometry or home PEFR) correlated with mean daily bronchodilation. For albuterol, the number of days of hospitalization was less than half that for patients on placebo (1.0/patient on albuterol versus 2.6 on placebo), but this did not reach statistical significance. These results suggest a beneficial effect from maintenance therapy with albuterol. Bronchodilation alone probably cannot explain the long-term benefits of albuterol, and other mechanisms may play a role. The lack of significant difference between change on albuterol and change on placebo is probably due to too small a number of patients in this study and lack of statistical power. Pediatr. Pulmonol. 1998; 25:32–37. © 1998 Wiley-Liss, Inc. 相似文献
994.
Ultrafast computed tomography (CT) can be performed in almost all children with little or no sedation. The benefit has to be balanced against financial cost and radiation dose. Since observing a steady increase in numbers of scans performed, we analyzed the contribution to management of 106 pediatric chest CT scans performed over a 12-month period. Forty-eight of 106 yielded a positive diagnosis and a further 43/106 provided clearly useful information. CT was most useful in children with chronic productive cough (21/48 scans showed bronchiectasis) and suspected interstitial lung disease. It was least useful in the preoperative assessment of empyema complicating community-acquired pneumonia (0/11 scans giving information that changed management). We conclude that the increased ease of performance of chest CT in children has not led to a large number of inappropriate requests. In the large majority of cases, diagnostically useful information was provided. Pediatr Pulmonol. 1998; 26:389–395. © 1998 Wiley-Liss, Inc. 相似文献
995.
David Armstrong Keith Grimwood John B. Carlin Rosemary Carzino Jeremy Hull Anthony Olinsky Peter D. Phelan 《Pediatric pulmonology》1998,26(6):371-379
Limited data in children with cystic fibrosis (CF) suggest that respiratory viral infections during infancy result in substantial morbidity. Eighty of 101 (79%) infants with CF diagnosed by neonatal screening during 1991–1996 were recruited into a prospective, multiple-birth cohort study. We aimed to perform an initial, then annual bronchoalveolar lavage (BAL) for bacterial and viral culture, cytology, IL-8, and elastolytic activity over the following 2 years. When possible, BAL was also performed during any hospitalization for a pulmonary exacerbation, and additional specimens for viral culture were collected by nasopharyngeal aspiration. Thirteen infants undergoing bronchoscopy for congenital stridor served as disease controls. During infancy, 31 children (39%) were hospitalized for respiratory disease and 20 (65%) cases had an etiologic agent identified. Respiratory viruses were detected in 16/31 (52%) cases, including four with simultaneous bacterial infection. Another four were infected with Staphylococcus aureus. Respiratory syncytial virus predominated and was found in seven infants. In the absence of bacteria, those with viral infections had acute onset of respiratory distress, were not treated with antibiotics, and had an uncomplicated hospital course. Compared to noninfected CF subjects and controls, infected infants had elevated BAL inflammatory indices (P < 0.01). Eleven of 31 (35%) hospitalized infants followed for 12–60 months acquired Pseudomonas aeruginosa, compared with only three of 49 (6%) subjects not hospitalized for respiratory symptoms during infancy (risk ratio 5.8, CI 1.9, 24). We conclude that respiratory viruses are important causes of hospitalization in CF infants. While viral infections were self-limited, they were accompanied by airway inflammatory changes, and admission to hospital was associated with early acquisition of Pseudomonas aeruginosa and persistent respiratory symptoms. Pediatr Pulmonol. 1998; 26:371–379. © 1998 Wiley-Liss, Inc. 相似文献
996.
Stenotrophomonas maltophilia (SM) was recovered from 211 of 773 cystic fibrosis (CF) patients followed for at least one year, and seen between 1982 and 1994. Yearly prevalence (5.6% to 8.7%) and incidence rates (1.6% to 5.7%) showed no trends. SM persistence varied greatly and was unlike that of Pseudomonas aeruginosa. Fifty percent of SM-positive patients had only one positive culture and only 24 (11%) remained chronically infected. Although SM-positive patients were more likely to be hospitalized than SM-negative patients, for 55% of SM-positive patients, acquisition did not appear to follow hospitalization. Of 40 SM-positive patients who had a CF sibling, only 10 siblings were ever culture positive. When stratified by FEV1, the two-year survival for SM-positive with mild/moderate disease (98%) and severe disease (78%) was similar to that of our SM-negative patients. Five-year survival was only 40% for SM-positive patients with initially severe pulmonary status, compared with 72% for the SM-negative patients. Seventy percent of the original SM isolates were panresistant (susceptible to no more than one antimicrobial agent). Ten years later, panresistance was 84%. Despite our reassuring experience with SM, including lack of sibling concordance, the fact that the majority of our patients had no hospital exposure prior to acquisition, the high incidence of transient infection, and the seemingly unaffected two-year survival, there are insufficient data to definitively conclude that segregation of these patients would be beneficial. The increasing prevalence of multiply resistant gram-negative pathogens in CF patients suggests the need for continued caution with any panresistant pathogen. Pediatr Pulmonol. 1998;25:304–308. © 1998 Wiley-Liss, Inc. 相似文献
997.
998.
999.
1000.
Kimberly Brown M.D. Theresa Kristopaitis M.D. Sherri Yong M.D. Gregorio Chejfec M.D. Jack Pickleman M.D. 《Journal of gastrointestinal surgery》1998,2(6):533-536
Glucagon-producing neuroendocrine tumors typically present with a characteristic constellation of symptoms including necrolytic
migratory erythema, non-insulin-dependent diabetes, weight loss, anemia, glossifis, and an increased thrombotic tendency.
Most ghicagonomas are solid and arise in the body or tail of the pancreas. We report two cases of cystic glucagonoma, one
found incidentally in an asymptomatic patient and one in a patient with weight loss and diabetes but no rash. In the first
patient, distal pancreatectomy and splenectomy were curative, whereas the second patient continued to exhibit elevated serum
glucagon levels and symptoms of glucose intolerance in the absence of demonstrable metastases. Cystic glucagonoma is a unique
variant of classic glucagonoma and should be considered in the differential diagnosis of cystic pancreatic neoplasms. 相似文献