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   19761篇
  免费   1035篇
  国内免费   390篇
耳鼻咽喉   875篇
儿科学   554篇
妇产科学   343篇
基础医学   2635篇
口腔科学   1779篇
临床医学   1659篇
内科学   1654篇
皮肤病学   365篇
神经病学   1076篇
特种医学   1168篇
外国民族医学   4篇
外科学   3209篇
综合类   2386篇
现状与发展   1篇
预防医学   434篇
眼科学   836篇
药学   887篇
  12篇
中国医学   340篇
肿瘤学   969篇
  2024年   30篇
  2023年   206篇
  2022年   465篇
  2021年   632篇
  2020年   555篇
  2019年   493篇
  2018年   481篇
  2017年   513篇
  2016年   525篇
  2015年   570篇
  2014年   1023篇
  2013年   1079篇
  2012年   940篇
  2011年   974篇
  2010年   956篇
  2009年   966篇
  2008年   978篇
  2007年   920篇
  2006年   904篇
  2005年   835篇
  2004年   701篇
  2003年   631篇
  2002年   486篇
  2001年   483篇
  2000年   399篇
  1999年   411篇
  1998年   362篇
  1997年   371篇
  1996年   356篇
  1995年   287篇
  1994年   257篇
  1993年   255篇
  1992年   214篇
  1991年   217篇
  1990年   200篇
  1989年   187篇
  1988年   152篇
  1987年   130篇
  1986年   126篇
  1985年   151篇
  1984年   141篇
  1983年   64篇
  1982年   102篇
  1981年   106篇
  1980年   92篇
  1979年   64篇
  1978年   50篇
  1977年   40篇
  1976年   33篇
  1975年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
2.
Glaucoma is a leading cause of irreversible blindness. The use of topical eye drops to reduce intraocular pressure remains the mainstay treatment. These eye drops frequently contain preservatives designed to ensure sterility of the compound. A growing number of clinical and experimental studies report the detrimental effects of not only these preservatives but also the active pharmaceutical compounds on the ocular surface, with resultant tear film instability and dry eye disease. Herein, we critically appraise the published literature exploring the effects of preservatives and pharmaceutical compounds on the ocular surface.  相似文献   
3.
4.
5.
《The ocular surface》2020,18(1):108-113
PurposeAromatase inhibitors (AIs) limit the synthesis of oestrogen in peripheral tissues thus lowering levels of oestrogen. The primary aim was to evaluate whether women treated with AIs have altered dry eye symptoms and signs. A sub-aim was to investigate whether symptoms of dry eye in postmenopausal women were associated with symptoms of non-eye pain, ocular pain and self-rated pain perception.MethodsThis cross-sectional, observational, single visit study recruited 56 postmenopausal women (mean age 64.1 + 7.9 years) and 52 undergoing AI treatment (mean age 66.6 + 9.0). Ocular symptoms (OSDI, MGD14) and pain questionnaires (PSQ, OPAS) were administered and signs of dry eye and meibomian gland dysfunction were evaluated.ResultsAlmost half of each group reported dry eye symptoms, defined as OSDI>12 (48% control, 46% AI). The PSQ score was significantly higher in the AI group (p = 0.04). Neither frequency or severity of dry eye (or MGD) symptoms scores were significantly different between groups. In the AI group, meibomian gland expressibility score was worse (p = 0.003); there were no differences in any other signs. Higher OSDI scores were associated with higher OPAS eye-pain scores (r = 0.49, p < 0.001), but not OPAS non-eye pain (r = 0.09, p = 0.35). Pain perception (PSQ) showed a moderate positive association with OPAS eye-pain (r = 0.30, p = 0.003).ConclusionsIn this study elevated ocular symptoms were observed in both the AI treated and the untreated groups, with no difference between the groups. Women undergoing AI treatment for early stage breast cancer had worse meibum expressibility score and increased pain perception compared to an untreated group of women.  相似文献   
6.
7.
《The ocular surface》2020,18(4):657-662
PurposeTo determine if meibomian gland architecture in a pediatric population is impacted by body mass index (BMI).MethodsProspective evaluation of 175 eyes of 175 pediatric patients from two clinics. Demographic and clinical information were reviewed. Symptoms of dry eye were assessed with the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire. Meibography was performed and grading of images was performed by a masked rater using a previously validated 5-point meiboscale (0–4) for gland atrophy and a 3-point score (0–2) for gland tortuosity.Results175 eyes of 175 participants aged 4–17 years (11.6 ± 3.7 years) were imaged. The mean meiboscore was 0.82 ± 0.94 (range 0–4) and the mean gland tortuosity score was 0.53 ± 0.70 (range 0–2). Ninety-six patients (56%) showed evidence of gland atrophy (meiboscore greater than 0) and the majority of patients (n=50, 29%) had a gland tortuosity score of 1. The mean BMI was 20.5 ± 4.86 kg/m2 with 39.4% of patients (n = 69) above the 85th percentile. BMI percentile was not found to be a significant predictor of a meiboscore greater than 0 (odds ratio (OR) 1.004 95% confidence interval (CI) (0.99–1.10, p = 0.41). However, BMI percentile was found to be a significant predictor of gland tortuosity score (OR 1.01 95% CI (1.00–1.02), p = 0.02). Patients with BMI percentiles between 41 and 60 were 3.79 times more likely to have a gland tortuosity score of greater than 0 than patients with BMI percentiles between 0 and 20 (OR 3.789 CI (1.17–12.24)). No significant associations were found between age, race, or sex and meiboscore or tortuosity. There was a trend towards reduction in lipid layer thickness with increasing BMI percentile (p = 0.028, r2 = 0.04).ConclusionIn this pediatric population, there was an association between meibomian gland tortuosity and higher percentiles of BMI. Future studies are needed to elucidate the pathogenesis of meibomian gland tortuosity and atrophy in pediatric patients.  相似文献   
8.
Respiratory cysts are benign lesions lined by normal respiratory epithelium. There are few reported cases localized to the orbit, while those of the eyelid are exceedingly rare. Respiratory cysts usually arise either from a non‐hereditary congenital malformation, where they are distinguished as choristomatous, or from trauma. Here, we report a case of a 53‐year‐old man who presented with a large right lower eyelid cyst that was histopathologically diagnosed as a respiratory cyst.  相似文献   
9.
Rationale:Tarlov or perineurial cysts are nerve root lesions often found in the sacral region. Most perineural cysts (PCs) remain asymptomatic throughout a patient''s life. While their pathogenesis is still unclear, trauma resulting in hemorrhaging into subarachnoid space has been put forward as a possible cause of these cysts. Recently, we worked with a patient experiencing symptomatic PCs after spontaneous subarachnoid hemorrhage.Patient concerns:A 45-year-old man had a coil embolization procedure performed after being diagnosed with a subarachnoid hemorrhage from a ruptured anterior communicating artery. His symptoms were relieved after the procedure, but 7 days later he reported worsening pain in the left perineal area. The pain was intermittent at its onset and exacerbated by sitting, walking, and coughing.Diagnoses:Two weeks after the embolization procedure, a lumbar spine MRI revealed 2 PCs at the S1 and S2 level affecting the left S2 root with high signal intensity in T2 and T1 images, suggestive of bleeding within the cyst.Interventions:We operated using a posterior approach. Cyst fenestration was done after S1 laminectomy. We aspirated approximately 1 cc of old blood.Outcomes:His pain was relieved immediately after cyst removal and no neurologic deterioration occurred during the postoperative period.Lessons:Subarachnoid hemorrhage can be the source of the development of pain from asymptomatic PCs, making them symptomatic. Surgical extirpation is 1 treatment option for these symptomatic PCs.  相似文献   
10.
Choledochal cysts (CDCs) and biliary atresia (BA) are rare pediatric hepatobiliary anomalies that require surgical intervention due to increased risk of malignancy and liver failure, respectively. The underlying disease and operative procedures place patients at risk for long‐term complications, which may continue to affect them into adulthood. Lack of a transitional care model in the health‐care system potentiates the challenges they will face following aging out of their pediatric providers' care. We sought to elucidate the long‐term complications and challenges patients with CDCs and BA face, review the current literature regarding transitioning care, and propose guidelines aiding adult providers in continued care and surveillance of these patients. A literature review was performed to assess short‐term and long‐term complications after surgery and the current standards for transitioning care in patients with a history of CDCs and BA. While transitional programs exist for patients with other gastrointestinal diseases, there are few that focus on CDCs or BA. Generally, authors encourage medical record transmission from pediatric to adult providers, ensuring accuracy of information and compliance with treatment plans. Patients with CDCs are at risk for developing biliary malignancies, cholangitis, and anastomotic strictures after resection. Patients with BA develop progressive liver failure, necessitating transplantation. There are no consensus guidelines regarding timing of follow up for these patients. Based on the best available evidence, we propose a schema for long‐term surveillance.  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