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   75827篇
  免费   5311篇
  国内免费   1628篇
耳鼻咽喉   3092篇
儿科学   898篇
妇产科学   1510篇
基础医学   1861篇
口腔科学   3135篇
临床医学   7080篇
内科学   7154篇
皮肤病学   700篇
神经病学   2535篇
特种医学   1234篇
外国民族医学   21篇
外科学   26328篇
综合类   10344篇
现状与发展   7篇
一般理论   2篇
预防医学   2700篇
眼科学   4564篇
药学   3049篇
  164篇
中国医学   837篇
肿瘤学   5551篇
  2024年   167篇
  2023年   2012篇
  2022年   2496篇
  2021年   4166篇
  2020年   4134篇
  2019年   3521篇
  2018年   3370篇
  2017年   2918篇
  2016年   2922篇
  2015年   2957篇
  2014年   5828篇
  2013年   5429篇
  2012年   4379篇
  2011年   4597篇
  2010年   3644篇
  2009年   3459篇
  2008年   3300篇
  2007年   3292篇
  2006年   2872篇
  2005年   2519篇
  2004年   2185篇
  2003年   1757篇
  2002年   1390篇
  2001年   1318篇
  2000年   1134篇
  1999年   1041篇
  1998年   855篇
  1997年   819篇
  1996年   609篇
  1995年   496篇
  1994年   436篇
  1993年   351篇
  1992年   297篇
  1991年   293篇
  1990年   198篇
  1989年   193篇
  1988年   193篇
  1987年   194篇
  1986年   153篇
  1985年   169篇
  1984年   158篇
  1983年   101篇
  1982年   105篇
  1981年   95篇
  1980年   76篇
  1979年   44篇
  1978年   33篇
  1977年   32篇
  1976年   24篇
  1975年   20篇
排序方式: 共有10000条查询结果,搜索用时 424 毫秒
991.
We report a surgically treated case of early infantile epileptic encephalopathy (EIEE) with suppression-bursts associated with focal cortical dysplasia. Tonic-clonic seizures followed by a series of spasms occurred about a hundred times a day at a few days of age. Interictal electroencephalogram (EEG) revealed a suppression-burst pattern that was predominant in the left hemisphere. Magnetic resonance imaging (MRI) suggested focal cortical dysplasia in the left prefrontal area. Combination therapies with antiepileptic treatments showed only partial efficacy. The patient underwent lesionectomy at age 4 months, after which he gradually showed psychomotor development and a decrease of spasms to 0-2 series daily. In cases of EIEE with focal cortical dysplasia, surgical treatment may have beneficial effects on both psychomotor development and seizure control.  相似文献   
992.
Fujii M  Akimura T  Ozaki S  Kato S  Ito H  Neshige R 《Epilepsia》1999,40(3):377-381
We present an unusual case of a patient who was diagnosed with temporal lobe epilepsy and whose seizures were reduced markedly after excision of an angiographically occult arteriovenous malformation (AVM) located in the left medial parietal lobe. A 38-year-old man had complex partial seizures characterized by motionless staring with oroalimentary and behavioral automatisms since the age of 15 years. Magnetic resonance imaging (MRI) demonstrated a small lesion extending from the left posterior cingulate gyrus to the precuneus. There was no MRI evidence of mesial temporal sclerosis. Intracranial EEG recordings showed ictal onset from the left medial parietal lobe propagating to the medial temporal lobes. Clinical signs appeared when these discharges reached the temporal lobes. After excision of the lesion (which was histologically confirmed as an AVM), together with the marginal cortex, seizures were reduced significantly. Careful diagnostic evaluation of lesions such as the this one may reveal an epileptogenic lesion (zone) far from the region where scalp ictal discharges seem to arise. In our case, we hypothesize that false localization was due to propagation of ictal discharges from the parietal focus through the limbic system.  相似文献   
993.
目的为进一步提高神经血管减压术治疗特发性偏侧面肌痉挛的疗效。方法经乙状窦后小骨窗开颅加用内窥镜辅助显微血管减压术治疗特发性偏侧面肌痉挛35例。结果术后34例症状消失,1例症状减轻,35例随访6个月至3年半,术后面肌抽搐消失者33例,1例症状减轻,1例1年后复发。结论内窥镜可弥补手术显微镜的不足之处,减少组织损伤和判断错误,提高治疗效果。  相似文献   
994.
Rajaraman V  Schulder M 《Surgical neurology》1999,52(6):70-8; discussion 598-9
BACKGROUNDKnowledge of the magnetic resonance imaging (MRI) appearance of the pituitary fossa following transsphenoidal resection of a pituitary adenoma, in the early and late postoperative period, is important for detecting complications and for assessing extent of tumor excision. Few prospective studies have addressed this issue.METHODSFourteen patients with pituitary macroadenomas were prospectively studied with MRI. Maximal tumor resection was accomplished in each patient, and the postoperative histological diagnoses included non-secreting adenoma in 11 patients, prolactinoma in 2 and necrosis in one. Early postoperative scans were obtained within 14 days after surgery, and late studies between 3 and 4 months, in all patients. Four patients also had delayed scans between 8 months and a year. The maximum coronal dimension (MCTD) of the sellar and suprasellar contents was measured on T1-weighted contrast enhanced scans.RESULTSAll patients had normal or improved visual examinations and normal or improved hormonal function postoperatively. The preoperative MCTD ranged from 11 mm to 59 mm in height (mean 30.3 mm). There was little change in MCTD on the early postoperative MRI scans (range 7–49 mm, mean 23.5 mm). However, in all patients the MCTD decreased in height by 4 months (range 2–35 mm, mean 12.7 mm). This change represented a 58% mean reduction in size compared to the preoperative measurements.CONCLUSIONSWe conclude that the appearance of the sellar contents on early postoperative MRI may appear remarkably similar to that seen before surgery, even after technically adequate resection. The postoperative mass may represent a combination of residual tumor, edema, postoperative hemorrhage and hemostatic material. Routine follow-up MRI after transsphenoidal resection of pituitary tumors may be delayed until at least 4 months after surgery in patients who are clinically stable.  相似文献   
995.
The objective of this study was to investigate whether nitric oxide (NO) inhalation might be an alternative strategy as a chemical assist for the circulation in patients showing a deterioration in oxygen delivery. Twelve adult patients whose oxygen delivery indices (DO2I) were less than 400 ml/min/m2 after cardiovascular surgery were included in this study. NO was administered via a premixing system or a side stream system at doses between 1 and 10 (5.1+/-2.4) ppm. Data obtained before and during a 120 min NO inhalation were compared using the paired Student's t-test. The increase in PaO2/FiO2 resulting from NO inhalation was significant (from 162 to 251 mm Hg). DO2I increased significantly from 326 to 417 ml/min/m2 concomitantly with significant increases in both arterial oxygen content (CaO2) and cardiac index (CI) (from 14.1 to 15.4 vol% and from 2.31 to 2.71 L/min/m2 , respectively). The increase in SvO2 during NO inhalation was significant (from 55.2 to 62.6%). Among the other hemodynamic parameters, both total pulmonary resistance and systolic pulmonary arterial pressure (SPAP) showed significant decreases during NO inhalation, but right atrial pressure did not change significantly. There was a close relationship between the baseline SPAP level (bSPAP) and the decrease in SPAP during NO inhalation (dSPAP) (r = -0.88). However, negative correlations were observed between bSPAP and percentage increase in CI (%CI) (r = -0.61) and between bSPAP and percentage increase in DO2I (%DO2I) (r = -0.48). Moreover, positive relationships were observed between dSPAP and %CI (r = 0.62) and between dSPAP and %DO2I (r = 0.45). Hemoglobin (Hb) increased significantly from 11.0 to 11.4 g/dl. There were no significant changes in Fio2, pH, PacO2, or base excess (BE) during NO inhalation. The level of methemoglobin measured during the study period remained within the normal range (0.86+/-0.23%). In conclusion, NO inhalation could be an efficient and alternative assist for the circulation in patients whose oxygen delivery deteriorates after cardiovascular surgery.  相似文献   
996.
This report concerns one case of a sphenoid sinus mucocele occurring 17 years after transsphenoidal surgery for acromegaly. In 1979, a 51-year-old man was successfully operated by the transnasal transsphenoidal approach for a growth hormone (GH) adenoma 1 cm in diameter. In 1996, the patient was hospitalized for headaches and diplopia. He presented a loss of right visual acuity with paralysis of the right oculomotor nerve. The basal GH level was normal with a satisfactory decrease after oral glucose ingestion. Pituitary sellar radiography showed a disappearance of the posterior clinoid while magnetic resonance imaging revealed the existence of a bilocular, circular, homogeneous lesion of the sphenoid sinus 3 cm in diameter with a posterior and lateral extension. The diagnosis of mucocele was confirmed by surgical treatment, allowing drainage of the mucocele through a transsphenoidal approach. The drained material was composed of sinus epithelium containing many polynuclear and resorptive cells. Postoperatively, the symptoms decreased dramatically, leading to full recovery of visual function and disappearance of the headaches. Apart from the tumor recurrence, the mucocele of the sphenoid sinus can be evoked as a possible long term complication of transsphenoidal sugery for pituitary adenoma. Received: 2 June 1998 / Accepted: 23 February 1999  相似文献   
997.
Craniofacial surgery concepts developed originally for reconstruction may also be applied to aesthetic surgery. The facial skeleton is an important component of appearance and may be modified using common craniofacial surgery techniques. Three representative male patients are presented, who each desired an improvement in his appearance. The techniques used were different and combined orthognathic and remodeling procedures. Aesthetic male facial skeletal surgery was beneficial in these selected cases. The results were well received and without complications. Surprisingly, we have found that male skeletal aesthetic patients did not have unrealistic expectations and were pleasant to manage pre- and postoperatively.  相似文献   
998.
窥镜下激光治疗前列腺增生症   总被引:2,自引:0,他引:2  
Li Q  Liu J  Xu X  Hou Z  Zhuang H  Xue J  Wang J  Cao Y 《中华外科杂志》1999,37(6):361-363
目的 评价经尿道激光前列腺切除术(TULP)的疗效及其与前列腺大小的关系。方法 回顾分析了1988年至1998年10年,采用TULP治疗的469例前列腺增生症患者对手术技术、手术前后的症关改善情况进行比较,并对233例符合条件的患者TULP手术效果与前列腺大小的相关性进行了研究。结果 469例患者前列腺症状评分(IPSS)平均值由术前的26.7降到术后的14.2;最大尿流率平均值由6.2ml/s上  相似文献   
999.
为评价开窗术治疗腰推间盘突出症的疗效 ,总结 1991年以来应用三维立体定位开窗术治疗腰椎间盘突出症 5 3例的疗效情况。结果 :经 2个月~ 7年随访 ,以Greenough评价标准分析 ,治疗后达到优 48例 ,良3例 ,可 2例 ,差 0例 ,优良率 96% ,无 1例出现并发症。结论 :①依据电子计算机体层摄影 (CT)、磁共振成像 (MRI)对腰椎间盘突出做出精确的三维立体定位是手术成功关键 ;②开窗法摘除腰椎间盘 ,组织损伤少 ,康复时间短 ,不影响后期脊椎稳定性 ,远期疗效满意  相似文献   
1000.
冠脉搭桥术:8例经验体会   总被引:1,自引:0,他引:1  
目的 总结冠脉搭桥术( C A B G) 的临床经验和体会、寻找最佳的围术期处理方法。方法 分析8 例 C A B G 患者完整的临床资料。心绞痛7 例,陈旧性心肌梗塞伴左室室壁瘤形成及发作性心绞痛1 例。并发高血压病者6 例,糖尿病3 例。 N Y H A 心功能Ⅱ级1 例,Ⅲ级4 例,Ⅳ级3 例。内乳动脉替代7 例,共用大隐静脉桥15 支。结果 1 例,术后因对角支静脉桥出血,行第2 次开胸修补止血。次2 日又因胸骨裂开,第3 次开胸行胸骨再固定术。全组无手术死亡病例,出院时心绞痛症状完全缓解。结论  C A B G 成功的关键除病变部位的准确诊断外,桥的获取及良好的心肌保护至关重要。  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