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   5119篇
  免费   554篇
  国内免费   75篇
耳鼻咽喉   69篇
儿科学   35篇
妇产科学   8篇
基础医学   420篇
口腔科学   27篇
临床医学   188篇
内科学   144篇
皮肤病学   45篇
神经病学   368篇
特种医学   77篇
外科学   84篇
综合类   321篇
一般理论   1篇
预防医学   111篇
眼科学   3308篇
药学   384篇
中国医学   93篇
肿瘤学   65篇
  2024年   31篇
  2023年   93篇
  2022年   161篇
  2021年   211篇
  2020年   207篇
  2019年   180篇
  2018年   206篇
  2017年   208篇
  2016年   214篇
  2015年   203篇
  2014年   238篇
  2013年   522篇
  2012年   217篇
  2011年   289篇
  2010年   232篇
  2009年   239篇
  2008年   224篇
  2007年   217篇
  2006年   195篇
  2005年   162篇
  2004年   159篇
  2003年   130篇
  2002年   107篇
  2001年   106篇
  2000年   73篇
  1999年   64篇
  1998年   76篇
  1997年   64篇
  1996年   43篇
  1995年   51篇
  1994年   34篇
  1993年   36篇
  1992年   26篇
  1991年   30篇
  1990年   33篇
  1989年   29篇
  1988年   31篇
  1987年   24篇
  1986年   28篇
  1985年   61篇
  1984年   60篇
  1983年   43篇
  1982年   47篇
  1981年   38篇
  1980年   46篇
  1979年   17篇
  1978年   20篇
  1977年   5篇
  1976年   11篇
  1969年   2篇
排序方式: 共有5748条查询结果,搜索用时 671 毫秒
101.
Myasthenia gravis (MG) is a disease that affects the neuro-muscular junction resulting in classical symptoms of variable muscle weakness and fatigability. It is called the great masquerader owing to its varied clinical presentations. Very often, a patient of MG may present to the ophthalmologist given that a large proportion of patients with systemic myasthenia have ocular involvement either at presentation or during the later course of the disease. The treatment of ocular MG involves both the neurologist and ophthalmologist. Thus, the aim of this review was to highlight the current diagnosis, investigations, and treatment of ocular MG.  相似文献   
102.
Ocular involvement of rhinosporidiosis is seen in about 15% of cases and clinically appears as a freely mobile, granular, pink, fleshy sessile or pedunculated mass. The conjunctiva is the most common site of origin. A 25-year-old male presented with a painless mass in the lower part of the left eye for 6 months which was gradually progressive. Examination revealed a pedunculated mass of 15 mm x 15 mm arising from the lower palpebrae of the left eye retracting the lower lid. It appeared to be vascular with few white spots at the apex. Rest of the ocular examinations was within the normal limit. The presentations of ocular rhinosporidiosis vary. Though the conjunctival origin is very common, it may not have a classic pink fleshy appearance at all times. A vascular/cystic painless conjunctival mass should also be considered as a case of rhinosporidiosis in prone areas.  相似文献   
103.
Primary intraocular lymphoma (PIOL) is an ocular malignancy that is a subset of primary central system lymphoma (PCNSL). Approximately one-third of PIOL patients will have concurrent PCNSL at presentation, and 42–92% will develop PCNSL within a mean of 8–29 months. Although rare, the incidence has been rising in both immunocompromised and immunocompetent populations. The majority of PIOL is diffuse large B-cell lymphoma, though rare T-cell variants are described. Recently, PIOL has been classified by main site of involvement in the eye, with vitreoretinal lymphoma as the most common type of ocular lymphoma related to PCNSL. Diagnosis remains challenging for ophthalmologists and pathologists. PIOL can masquerade as noninfectious or infectious uveitis, white dot syndromes, or occasionally as other neoplasms such as metastatic cancers. Laboratory diagnosis by cytology has been much aided by the use of immunocytochemistry, flow cytometry, biochemical finding of interleukin changes (IL10:IL6 ratio > 1), and cellular microdissection with polymerase chain reaction amplification for clonality. Use of several tests improves the diagnostic yield. Approaches to treatment have centered on systemic methotrexate-based chemotherapy, often with cytarabine (Ara-C) and radiotherapy. Use of intravitreal chemotherapy with methotrexate (0.4 mg/0.1 mL) is promising in controlling ocular disease, and intravitreal rituximab (anti-CD20 monoclonal antibody) has also been tried. Despite these advances, prognosis remains poor.  相似文献   
104.
里昂化作用(Lyonization)又称X染色体失活,是指雌性哺乳类动物细胞中两条X染色体的其中之一失去活性的现象.一些眼部X连锁隐性遗传病如先天性无脉络膜症、视网膜色素变性、X-连锁眼部白化病等都有里昂化作用的参与.通过了解里昂化作用将有助于眼部X连锁隐性遗传病的诊断及治疗.  相似文献   
105.
106.
The highest quality gray-scale ultrasound images are obtained with high-frequency transducers; however, such high frequencies do not penetrate more than a few centimeters into body tissue. Fortunately, in patients with melanoma, the structures of interest are close to the skin surface, making them ideal targets for examination with high-resolution ultrasound. These include primary cutaneous melanomas, uveal melanomas and the regional lymph nodes draining the skin that lie in the axilla, groin, neck and other locations. Although ultrasound study of primary melanomas arising in the skin and eye has provided some insights, a major role for ultrasound has evolved recently, to provide early detection of metastatic melanoma in regional lymph nodes. Ultrasound is clearly superior to clinical palpation of the nodes during follow-up and, when combined with guided fine-needle biopsy, allows the earliest possible surgical intervention for regional nodal metastases. In the future the use of ultrasound contrast agents may improve the sensitivity of ultrasound in the detection of very small metastatic deposits.  相似文献   
107.
Purpose: To assess the value of positive immunoglobulin (Ig) M serum antibody (Ab) findings in uveitis patients.

Methods: We reviewed medical records of patients who had a positive serological test for Toxoplasma gondii-specific IgM Ab. Their clinical data, including history, demographic characteristics, laboratory findings, clinical findings, treatment outcomes, and recurrences, were reviewed retrospectively.

Results: Of 2919 uveitis patients who underwent a serological test for suspected ocular toxoplasmosis (OT), 18 presented with positive Ig M results. All 18 patients (100.0% specificity) were clinically diagnosed with OT. None had any retinochoroidal scar at the initial visit, indicating the OT was a recent and primary infection. However, 15 patients (83.3%) had no history suspected to account for the Toxoplasma transmission.

Conclusions: The T. gondii IgM serum Ab is a specific biomarker for diagnosis of primary OT. Epidemiological studies are warranted to investigate the non-classic transmission routes of T. gondii in OT.  相似文献   

108.
目的探讨日光温室作业对蔬菜种植人员眼健康的影响。方法选取西北某地区739名温室蔬菜种植人员(温室组)和263名非温室蔬菜种植人员(非温室组)作为研究对象,采用问卷调查方式收集其一般人口学信息和眼异常症状情况,并测量双侧裸眼视力。结果温室组和非温室组人员左眼视力分别为4.89±0.33和4.91±0.25,差异无统计学意义(P>0.05);右眼视力分别为4.86±0.32和4.91±0.24,差异具有统计学意义(P<0.05)。男性温室组右眼视力(4.89±0.38)低于非温室组(4.98±0.22),差异具有统计学意义(P<0.05);女性温室组与非温室组右眼视力分别为4.84±0.28和4.89±0.24,差异无统计学意义(P>0.05)。温室组和非温室组眼痒、眼干等眼部异常症状发生率差异均无统计学意义(P>0.05)。多因素分析显示,年龄、性别和眼异常症状种类数是影响视力的重要因素(P<0.05);女性和温室作业人员更易出现眼异常症状(P<0.05)。结论日光温室作业可能引起蔬菜种植人员眼损伤风险升高,主视眼视力可能更易受损。  相似文献   
109.
BackgroundThe timely evaluation of ocular conditions in the emergency department (ED) can be difficult due to a general lack of specialized equipment, trained personnel, and the time-sensitive nature of emergent ocular conditions. Recently, the use of ocular point-of-care ultrasound (POCUS) has been shown to be particularly useful in the ED. POCUS can be used to promptly diagnose various ocular pathologies, which include ocular trauma, vitreous hemorrhage, central retinal artery occlusion, and retinal detachment.ObjectivesThis narrative review seeks to inform the reader of current literature regarding the use of POCUS for the assessment of various ocular emergencies in the ED. The goal of this review is to provide the emergency physician with succinct and up-to-date information and instruction regarding the current uses of POCUS for patients presenting with particular ocular emergencies. Ocular pathologies that are common (ocular trauma) or for which ultrasound is particularly useful (such as retinal detachment) are discussed. Other ocular pathologies are also briefly discussed, such as central retinal artery occlusion, which is a promising new application for ultrasound evaluation.DiscussionThere have been many studies that provide evidence for the utility of POCUS in the evaluation of trauma and other ocular pathologies, including vitreous hemorrhage, retinal detachment, and central retinal artery occlusion.ConclusionsOcular POCUS is a useful modality in the evaluation of acute ocular complaints in the ED. Emergency physicians should be aware of these findings and feel confident in the utility of ocular POCUS in the ED.  相似文献   
110.
A 53-year-old woman with hemiparesis and poor dexterity, underwent cosmetic blepharopigmentation on the both upper eyelids in the dermatology clinic of a private hospital. She was not asked for any information on her medical history and no informed consent was obtained and the procedure was performed without any protective ocular shields. The patient experienced severe lacrimation, discomfort, and increased sensitivity to light during and after the procedure. She also noticed blurred vision after the procedure. Ophthalmologic examination revealed tender and oedematous eyelids and corneal abrasions in both of her eyes. Topical antibiotics and preservative-free lubricants were able to recover her from her signs and symptoms at 1-week follow-up. It is recommended that cosmetic blepharopigmentation should be applied cautiously with patient’s informed consent after obtaining a thorough medical history and with protective ocular shields to avoid potential complications.  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