全文获取类型
收费全文 | 2862篇 |
免费 | 205篇 |
国内免费 | 140篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 18篇 |
妇产科学 | 16篇 |
基础医学 | 192篇 |
口腔科学 | 54篇 |
临床医学 | 243篇 |
内科学 | 210篇 |
皮肤病学 | 18篇 |
神经病学 | 65篇 |
特种医学 | 143篇 |
外科学 | 385篇 |
综合类 | 950篇 |
预防医学 | 300篇 |
眼科学 | 22篇 |
药学 | 174篇 |
中国医学 | 184篇 |
肿瘤学 | 217篇 |
出版年
2024年 | 5篇 |
2023年 | 6篇 |
2022年 | 12篇 |
2021年 | 30篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 33篇 |
2017年 | 27篇 |
2016年 | 23篇 |
2015年 | 40篇 |
2014年 | 50篇 |
2013年 | 84篇 |
2012年 | 58篇 |
2011年 | 44篇 |
2010年 | 60篇 |
2009年 | 67篇 |
2008年 | 57篇 |
2007年 | 191篇 |
2006年 | 166篇 |
2005年 | 112篇 |
2004年 | 339篇 |
2003年 | 553篇 |
2002年 | 436篇 |
2001年 | 370篇 |
2000年 | 181篇 |
1999年 | 59篇 |
1998年 | 29篇 |
1997年 | 24篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有3207条查询结果,搜索用时 15 毫秒
1.
COPD机械通气病人下呼吸道感染致病菌分布特点 总被引:1,自引:0,他引:1
①目的 探讨慢性阻塞性肺病(COPD)病人机械通气后下呼吸道感染致病菌的特点。②方法 取32例COPD并发呼吸衰竭行机械通气病人下呼吸道分泌物做痰细菌学培养,同时做药物敏感试验。③结果 32例病人共分离出菌株76株,阳性率71.7%,其中混合感染10例次。其中革兰阴性杆菌(GNB)58株,占76.3%;阳性球菌10株,占13.2%;真菌8株,占10.5%。常见致病菌以铜绿假单胞菌、鲍曼不动杆菌和肺炎杆菌为主,GNB中铜绿假单胞菌和不动杆菌的耐药率高。④结论 COPD应用机械通气病人下呼吸道感染以革兰阴性杆菌为主,耐药性高。 相似文献
2.
神经导航内窥镜辅助下单鼻孔入路垂体腺瘤切除 总被引:1,自引:1,他引:0
目的神经导航、内窥镜辅助下垂体腺瘤的经单鼻孔经蝶手术治疗。方法对6例经磁共振成像诊断垂体腺瘤的病人术前进行磁共振成像定位,将影像资料输入导航工作站,作术前手术计划。采用零度及45度镜经单鼻腔,在导航的动态指引下确认鞍底,于内窥镜下实施瘤实质切除。结果本组5例完全切除,1例因为瘤实质较韧而作大部分切除,术后病人的视力均得到了改善。导航预期误差1.48mm,实际误差1.8mm。结论神经导航引导下的经鼻蝶垂体腺瘤手术定位准确,内窥镜下操作对鼻腔的解剖结构影响小、组织损伤轻,病人恢复快。 相似文献
3.
目的 :进一步探讨 MRI增强前后的准备与护理方法。材料与方法 :共增强 833例 ,男 5 85例 ,女 2 4 8例。使用顺磁性造影剂 Gd- DTPA,按 0 .2 m L/kg体重给药。其中双倍量增强 110例 ,增强前认真履行告知义务和签署同意书。发生造影剂外漏者给予鲜马铃薯片外敷。结果 :增强效果达良好以上共 82 5例 ,占 99% ,未发生严重负反应。 3例造影剂外漏 ,鲜马铃薯片外敷后 3h痊愈。结论 :增强前充分细致的准备是保证增强效果的重要因素。认真履行告知义务和签置同意书 ,不仅尊重了病人的权利 ,也是依法行医 ,保证医疗安全的需要 相似文献
4.
Dendrites and spines undergo dynamic changes in physiological and pathological conditions. Dendritic outgrowth has been observed in surviving neurons months after ischemia, which is associated with the functional compensation. It remains unclear how dendrites in surviving neurons are altered shortly after ischemia, which might reveal the mechanisms underlying neuronal survival. Using primary cortical cultures, we monitored the dendritic changes in individual neurons after oxygen-glucose deprivation (OGD). Two to four hours of OGD induced approximately 30–50% cell death in 24 h. However, the total dendritic length in surviving neurons was significantly increased after OGD with a peak at 6 h after re-oxygenation. The increase of dendritic length after OGD was mainly due to the sprouting rather than the extension of the dendrites. The dendritic outgrowth after 2 h of OGD was greater than that after 4 h of OGD. Application of NMDA receptor blocker MK-801 abolished OGD-induced dendritic outgrowth, whereas application of AMPA receptor antagonist CNQX had no significant effects. These results demonstrate a NMDA receptor-dependent dendritic plasticity shortly after OGD, which provides insights into the early response of surviving neurons after ischemia. 相似文献
5.
6.
研究了β-环糊精/环氧氯丙烷水凝胶的合成工艺条件,发现该水凝胶透明性好,其干胶具有溶胀速度快的且在-40-200℃范围内不存在玻璃化转变,用DSC对β-环糊精/环氧氯丙烷水凝胶的溶胀过程及水在聚合物网络中的存在状态进行了研究,结果表明,该聚合物在溶胀过程中水首先分布于β-环糊精的外围亲水空间依次形成非冻结结结合水,可阈结结合水及游离水、其后水分布于β-环糊精内腔空间,当达到溶胀平均后,β-环糊精的内外空间都分布有水。 相似文献
7.
建立了蠕变局部损伤法模型,并给出单元进入损伤态的判据和失效的临界拉伸应变条件,局部蠕变损伤理论的实质就是试样是多种不同蠕变性能材料的统一,并由蠕变应力再分布得到证实,应用有限元对双缺口圆试样作了蠕变局部损伤分析,启裂时间和断裂蠕变应变值均与实验结果相吻合。 相似文献
8.
Ran Wei Chiao Yee Lim Yi Yang Xiaodong Tang Taiqiang Yan Rongli Yang Wei Guo 《Orthopaedic Surgery》2021,13(2):553
ObjectivesThis study aims to: (i) evaluate the outcome of patients with Harrington class III lesions who were treated according to Harrington classification; (ii) propose a modified surgical classification for Harrington class III lesions; and (iii) assess the efficiency of the proposed modified classification.MethodsThis study composes two phases. During phase 1 (2006 to 2011), the clinical data of 16 patients with Harrington class III lesions who were treated by intralesional excision followed by reconstruction of antegrade/retrograde Steinmann pins/screws with cemented total hip arthroplasty (Harrington/modified Harrington procedure) were retrospectively reviewed and further analyzed synthetically to design a modified surgical classification system. In phase 2 (2013 to 2019), 62 patients with Harrington class III lesions were classified and surgically treated according to our modified classification. Functional outcome was assessed using the Musculoskeletal Tumor Society (MSTS) 93 scoring system. The outcome of local control was described using 2‐year recurrence‐free survival (RFS). Owing to the limited sample size, we considered P < 0.1 as significant.ResultsIn phase 1, the mean surgical time was 273.1 (180 to 390) min and the mean intraoperative hemorrhage was 2425.0 (400.0 to 8000.0) mL, respectively. The mean follow‐up time was 18.5 (2 to 54) months. Recurrence was found in 4 patients and the 2‐year RFS rate was 62.4% (95% confidence interval [CI] 31.6% to 93.2%). The mean postoperative MSTS93 score was 56.5% (20% to 90%). Based on the periacetabular bone destruction, we categorized the lesions into two subgroups: with the bone destruction distal to or around the inferior border of the sacroiliac joint (IIIa) and the bone destruction extended proximal to inferior border of the sacroiliac joint (IIIb). Six patients with IIIb lesions had significant prolonged surgical time (313.3 vs 249.0 min, P = 0.022), massive intraoperative hemorrhage (3533.3 vs 1760.0 mL, P = 0.093), poor functional outcome (46.7% vs 62.3%, P = 0.093), and unfavorable local control (31.3% vs 80.0%, P = 0.037) compared to the 10 patients with IIIa lesions. We then modified the surgical strategy for two subgroup of class III lesions: Harrington/modified Harrington procedure for IIIa lesions and en bloc resection followed by modular hemipelvic endoprosthesis replacement for IIIb lesions. Using the proposed modified surgical classification, 62 patients in the phase 2 study demonstrated improved surgical time (245.3 min, P = 0.086), intraoperative hemorrhage (1466.0 mL, P = 0.092), postoperative MSTS 93 scores (65.3%, P = 0.067), and 2‐year RFS rate (91.3%, P = 0.002) during a mean follow‐up time of 19.9 (1 to 60) months compared to those in the phase 1 study.ConclusionThe Harrington surgical classification is insufficient for class III lesions. We proposed modification of the classification for Harrington class III lesions by adding two subgroups and corresponding surgical strategies according to the involvement of bone destruction. Our proposed modified classification showed significant improvement in functional outcome and local control, along with acceptable surgical complexity in surgical management for Harrington class III lesions. 相似文献
9.
10.
人眼眩光失能测定及其临床意义 总被引:1,自引:0,他引:1
目的:观察国产仪器测定眩光失能的性能与规律,并讨论其临床意义。方法:采用MGT—1多功能视觉眩光测试仪(海军医学研究所研制),按规定方法操作。测定正常人30名56眼(矫正视力全部≥1.0,晶体透明,无其他明显眼病),晶体混浊患者15人27眼。测定目标亮度及眩光亮度设置为中—中及弱—中两档分别模拟白天及夜间眩光失能。结果:中—中状态下,眩光失能值正常人均值为9.22%(全距0~31),低于晶体混浊者(24.05%,全距9~67),两者差异显著。正常眼在弱—中状态眩光失能值较中—中状态明显(均值20.12%,全距0~56)。不同频率条件对正常及晶体混浊眼眩光失能的影响不同,低频及中频较高频区的影响明显。结论:作为视功能评论指标,眩光失能检查是一种实用方法。在眼科临床及人体工效学上具有重要的意义。 相似文献