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   1071篇
  免费   85篇
  国内免费   15篇
耳鼻咽喉   50篇
儿科学   34篇
妇产科学   11篇
基础医学   148篇
口腔科学   12篇
临床医学   71篇
内科学   160篇
皮肤病学   23篇
神经病学   118篇
特种医学   177篇
外科学   120篇
综合类   27篇
预防医学   58篇
眼科学   9篇
药学   55篇
肿瘤学   98篇
  2022年   7篇
  2021年   18篇
  2020年   9篇
  2019年   13篇
  2018年   14篇
  2017年   12篇
  2016年   14篇
  2015年   23篇
  2014年   39篇
  2013年   32篇
  2012年   29篇
  2011年   53篇
  2010年   47篇
  2009年   42篇
  2008年   34篇
  2007年   53篇
  2006年   48篇
  2005年   43篇
  2004年   41篇
  2003年   40篇
  2002年   38篇
  2001年   29篇
  2000年   26篇
  1999年   16篇
  1998年   24篇
  1997年   43篇
  1996年   25篇
  1995年   27篇
  1994年   17篇
  1992年   15篇
  1991年   12篇
  1990年   22篇
  1989年   26篇
  1988年   18篇
  1987年   26篇
  1986年   13篇
  1985年   12篇
  1984年   10篇
  1983年   14篇
  1982年   9篇
  1981年   13篇
  1980年   15篇
  1977年   14篇
  1976年   10篇
  1975年   10篇
  1974年   7篇
  1973年   6篇
  1969年   8篇
  1968年   6篇
  1967年   9篇
排序方式: 共有1171条查询结果,搜索用时 46 毫秒
61.
Sentinel lymph node biopsy (SLNB) is a minimally invasive method that was developed to stage the regional lymphatics of patients with cutaneous melanoma. Many studies performed worldwide have shown that SLNB is a feasible method to stage the cervical lymphatics in patients with head and neck squamous cell carcinoma (HNSCC). The accuracy of SLNB in patients with HNSCC is currently under investigation in a multicenter study sponsored by the American College of Surgeons Oncology Group that compares the results of SLNB with standard elective neck dissection. Research to date has also shown that multiple SLNs and individualized drainage patterns characterize head and neck mucosal sites. These findings suggest that lymphoscintigraphy alone may be useful to delineate the lymphatic basins that require treatment in patients with HNSCC and in patients whose head and neck lymphatics are disrupted because of prior surgery or irradiation.  相似文献   
62.
The lack of epidemiological data on the frequency and/or burden of organic acidurias (OA) and mitochondrial fatty acid transport and oxidation disorders (mtFATOD) is one reason for hesitation to expand newborn screening (NBS) by tandem mass spectrometry (MS-MS). From 1999 to 2000, the frequency of ten potentially treatable OA and mtFATOD was assessed by active nation-wide surveillance on cases presenting with clinical symptoms using the German Paediatric Surveillance Unit (ESPED) system. Case ascertainment was complemented by a second independent source: 3-monthly inquiries in the metabolic laboratories performing secondary selected screening for OA and mtFATOD. Frequency estimates for clinically symptomatic cases older than 7 days in a birth cohort of 844,575 conventionally screened children was compared to the frequency found in a cohort of 382,247 screened by MS-MS in Bavaria and Baden-Württemberg. The overall frequency of the ten conditions considered was 1:8,000 (95% CI 1:11,000–1:6,000) by MS-MS as compared to 1:23,000 (95% CI 1:36,000–1:17,000) in symptomatic cases presenting mainly with metabolic crisis. The contributions of medium-chain acyl-CoA dehydrogenase deficiency (MCADD), other mtFATOD and OA were 29, 4 and 13 among the 46 cases identified by MS-MS, and 19, 1 and 13 among the 33 clinically symptomatic cases, respectively. Acute metabolic crisis, with a lethal outcome in four patients, was reported for 22/33 clinically symptomatic cases. No clinically symptomatic cases were reported from cohorts with screened by MS-MS. Conclusion: ten potentially treatable organic acidurias and mitochondrial fatty acid transport and oxidations disorders were more common than phenylketonuria with organic acidurias accounting for 28% of the cases detected by newborn screening and 39% of the cases identified on high risk screening. These conditions were related to considerable morbidity and mortality. Considerations for their inclusion in expanded newborn screening programmes might be warranted.Abbreviations ESPED Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland (German Paediatric Surveillance Unit) - MCADD medium-chain acyl-CoA dehydrogenase deficiency - MS-MS tandem mass spectrometry - mtFATOD mitochondrial fatty acid transport and oxidation disorders - NBS newborn screening - OA organic acidurias  相似文献   
63.
PURPOSE OF REVIEW: The purpose of this review is to discuss recent literature regarding diagnostic and management trends for recurrent respiratory papillomatosis (RRP) published within the past year. This includes a discussion of new information regarding the epidemiology and pathogenesis of RRP and an update on adjuvant therapy and new surgical techniques. RECENT FINDINGS: Epidemiological studies have confirmed that juvenile-onset RRP is the most common and most aggressive form of the disease. Age at diagnosis is the most important determinant of disease severity, with younger patients requiring significantly more annual surgeries and more likely to have multicentric disease. Distal tracheal or pulmonary RRP is rare, but carries a significant increase in morbidity and mortality. Research into the pathogenesis of RRP has focused on the genetics of HPV infection and host-virus interactions, suggesting a genetic basis for host susceptibility to RRP. At the present time, surgery remains the mainstay of treatment for RRP. However, recurrence after surgery is common and the search for effective adjuvant therapies is ongoing. The antiviral drug cidofovir has demonstrated efficacy against RRP and is considered a promising new adjuvant treatment of this disease. In an attempt to minimize the untoward effects of surgery, the pulsed-dye laser (PDL) has emerged as a safe and efficacious treatment for select patients with RRP. SUMMARY: While a cure for RRP remains elusive, there has been substantial progress in the diagnosis and management of this disease. Significant advances in clinical and basic science research have dramatically improved our understanding of the epidemiology and pathogenesis of the disease and led to the development of promising new adjuvant therapies and surgical techniques. This has translated to an improved quality of life for many patients with RRP.  相似文献   
64.
65.
66.
Diagnosis of dysplasia in the gastrointestinal tract has important clinical implications for management decisions. Although dysplasia is generally recognized by histology, cytologic specimens have been shown to increase the sensitivity of tissue diagnosis. The advantage of cytology is the ability to sample a much larger mucosal area. The relatively low specificity caused by the overlap in cytologic features of reactive atypia, dysplasia, and carcinoma is a disadvantage. This article reviews the cytology of squamous and glandular dysplasia in the alimentary tract as well as the studies that have evaluated the clinical utility of cytologic sampling of the gastrointestinal tract in the evaluation of dysplasia.  相似文献   
67.
Sentinel lymph node biopsy in head and neck squamous cell carcinoma   总被引:6,自引:0,他引:6  
OBJECTIVES/HYPOTHESIS: Sentinel lymph node biopsy is a minimally invasive method to stage the regional lymphatics that has revolutionized the management of patients with intermediate-thickness cutaneous melanoma. Head and neck surgeons have been encouraged by the accuracy of sentinel lymph node biopsy in cutaneous melanoma and have applied the technique to patients with head and neck squamous cell carcinoma (HNSCC). The objectives of the study were 1) to study the feasibility and accuracy of sentinel lymph node biopsy as a method to stage the regional lymphatics in HNSCC and 2) to determine whether there are qualitative differences between the cutaneous and mucosal lymphatics that would affect the technique used in HNSCC. STUDY DESIGN: Two methods of investigation were employed: a prospective laboratory study using a feline model for sentinel lymph node biopsy and a retrospective review of patients who received lymphoscintigraphy before neck dissection and intraoperative identification of the sentinel lymph node. METHODS: Lymphoscintigraphy and a gamma probe were used in four felines to study the kinetics of technetium-labeled sulfa colloid (Tc-SC) in the mucosal lymphatics. In the second part of the feline study, eight subjects were studied intraoperatively. Tc-SC and isosulfan blue dye were used to study the injection technique for the mucosal lymphatics and to determine the time course of the dye and Tc-SC to the sentinel lymph node. In Part II of the present study, a retrospective review of 33 patients with HNSCC was conducted. Twenty patients (stage N0) whose treatment included elective neck dissection were studied with preoperative lymphoscintigraphy and underwent intraoperative identification of the sentinel lymph node to determine the accuracy and feasibility of sentinel lymph node biopsy. Eight patients with palpable neck disease and five patients with recurrent or second primary disease whose previous treatment included neck dissection were also studied with lymphoscintigraphy before neck dissection. RESULTS: In the feline study, both Tc-SC and isosulfan blue dye traversed the lymphatics rapidly, appearing in the sentinel lymph node in less than 5 minutes. Modification of the injection technique used for cutaneous melanoma was required to depict the sentinel lymph node of the base of tongue. In the human study, the sentinel lymph node was accurately identified in 19 of 20 (95%) N0 patients. On average, 2.9 sentinel lymph nodes (range, 1-5) were identified in 2.2 (range, 1-4) levels of the neck. Sentinel lymph nodes were bilateral in 4 of 19 patients. When the sentinel lymph node was identified, it accurately predicted the pathological nodal status of the regional lymphatics. Three of 20 patients had cervical metastases, and the sentinel lymph node was identified in 2 of 3 patients with pathologic nodes (pN+). Focal areas of radiotracer uptake were identified in seven of eight patients with palpable disease. These areas corresponded to the level with palpable disease in four patients. The lymphatics delineated by lymphoscintigraphy in the five patients with previous neck dissection were outside the levels that had been dissected. Lymphoscintigraphy depicted collateral patterns of lymphatic drainage. CONCLUSIONS: Sentinel lymph node biopsy is technically feasible and is a promising, minimally invasive method for staging the regional lymphatics in patients with stage N0 HNSCC. Lymphoscintigraphy alone may determine the levels that require treatment in patients with disrupted or previously operated cervical lymphatics.  相似文献   
68.
Sentinel lymph node biopsy in head and neck cancer   总被引:2,自引:0,他引:2  
In the past decade, the technique of sentinel lymph node biopsy (SLNB) has been applied to a vast array of primary neoplasms, ranging from head and neck melanoma to vulvar carcinoma. At present, experience with SLNB is greatest in patients with melanoma and breast cancer. In view of the well known complications associated with cervical node dissection, it has been suspected for some time that cervical SLNB, if successful, might reduce the morbidity associated with the definitive care of patients with head and neck cancers. This report assesses the current status of SLNB in the treatment of head and neck cancers; while formal investigations of the efficacy of this technique are recommended, SLNB has not yet been demonstrated to possess the same level of utility seen in SLNB in melanoma and breast cancer patients. As a consequence, the application of SLNB to head and neck cancers remains an experimental technique--one which has not yet acquired the status of the standard of patient care.  相似文献   
69.
70.
Declarative memory impairment is a frequent complaint of patients suffering from posttraumatic stress disorder (PTSD). We assessed memory, attention, visual spatial skills, and executive function in Vietnam combat veterans with (n = 19) and without (n = 13) PTSD. Although PTSD subjects demonstrated a generalized impairment relative to non-PTSD subjects on a majority of tasks, only attention and memory provided unique and independent prediction of PTSD versus non-PTSD status. Our findings suggest that memory functioning represents a neurocognitive domain of specific relevance to the development of PTSD in trauma-exposed individuals, which can be distinguished from generalized attentional impairment as well as the effects of trauma exposure severity, IQ, comorbid depression, history of alcohol use, and history of developmental learning problems.  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