全文获取类型
收费全文 | 261篇 |
免费 | 32篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 10篇 |
妇产科学 | 1篇 |
基础医学 | 30篇 |
口腔科学 | 3篇 |
临床医学 | 47篇 |
内科学 | 32篇 |
皮肤病学 | 2篇 |
神经病学 | 29篇 |
特种医学 | 50篇 |
外科学 | 42篇 |
综合类 | 20篇 |
预防医学 | 11篇 |
眼科学 | 2篇 |
药学 | 37篇 |
中国医学 | 1篇 |
肿瘤学 | 23篇 |
出版年
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 11篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 33篇 |
2006年 | 5篇 |
2005年 | 14篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1997年 | 10篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 16篇 |
1992年 | 7篇 |
1991年 | 13篇 |
1990年 | 15篇 |
1989年 | 16篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
排序方式: 共有341条查询结果,搜索用时 15 毫秒
91.
H Wiksell H Martin H Coakham A Berggren S Westermark 《European Journal of Ultrasound》2000,11(1):41-46
OBJECTIVE: At present, ultrasonic aspiration is routinely used in several fields of surgery, especially in brain and spinal micro-surgery for tumour removal. In order to broaden the access to difficult surgical sites, it is important to design highly miniaturised but still efficient handpieces. The internal resonant system, always made of high-grade materials, must be optimally dimensioned. Normally this is done semi-empirically, by successively improving the design during many iterative test steps. This method however involves several additional difficulties when the degree of miniaturisation increases. For example, small transducer weights exacerbate heat-dissipation problems and make design optimisation important. METHODS: To resolve these problems we have produced modelling software that makes it possible to simulate and automatically tune each individual interacting section of the design before it is actually manufactured, thereby assuring optimal efficiency. RESULTS: Using a new mini-handpiece, designed via the software, two cases of dissection of acoustic neurinomas were successfully performed. CONCLUSION: Using conventional physical steps for improving ultrasonic aspiration handpieces, several problems arise when the grade of miniaturisation increases, due to increasing demands. We have designed computer software for handpiece simulation. Using this model it has been possible to manufacture a highly efficient miniaturised handpiece. 相似文献
92.
用放射配体受体结合法测定表明:克塞平对多巴胺D1受体的亲和力较异戊塞平高近20倍。两药对其它各受体的亲和力差別不大。慢性给药后,异戊塞平和克塞平均能使大鼠脑皮层5-HT2受体的密度显著下降,而亲和力变化不明显。这种下调5-HT2受体的作用发生在给异戊塞平后1~2周之间,给克塞平后的2~3周之间。慢性给药3周,异戊塞平和克塞平均未使大鼠脑皮层的β受体密度及亲和力产生显著变化。 相似文献
93.
Intraoperative monitoring during surgery for acoustic neuroma: benefits of an extratympanic intrameatal electrode 下载免费PDF全文
Mullatti N Coakham HB Maw AR Butler SR Morgan MH 《Journal of neurology, neurosurgery, and psychiatry》1999,66(5):591-599
OBJECTIVES: To assess the utility of an extratympanic intrameatal electrode for intraoperative monitoring during acoustic neuroma and other cerebellopontine angle tumour surgery and to define the neurophysiological and surgical factors which influence hearing preservation. METHODS: Twenty two patients, 18 with acoustic neuromas and four with other cerebellopontine angle tumours, underwent intraoperative monitoring during tumour excision. The extratympanic intrameatal electrode (IME) was used to record the electrocochleogram (ECoG) and surface electrodes to record the brainstem auditory evoked response (ABR). RESULTS: The compound action potential (CAP) of the ECoG was two and a half times greater in amplitude than wave I of the ABR and was easily monitored. Virtually instant information was available as minimal averaging was required. Continuous monitoring was possible from the commencement of anaesthesia to skin closure. The IME was easy to place, non-invasive, and did not interfere with the operative field. Operative procedures which affected CAP or wave V latency or amplitude were drilling around the internal auditory meatus, tumour dissection, nerve section, and brainstem and cerebellar retraction. Hearing was achieved in 59% of patients. CONCLUSIONS: The IME had significant benefits in comparison with other methods of monitoring. The technique provided information beneficial to preservation of hearing. 相似文献
94.
95.
1临床资料2003-10/2004-12住院老年多器官功能衰竭患者46例,全部为男性,年龄(79±5)岁.2个器官功能衰竭为A组15例,年龄(77±6)岁;3个以上器官功能衰竭为B组20例,年龄(79±7)岁;死亡为C组11例,年龄(78±4)岁;无重要脏器功能衰竭的老年患者20例为对照组,年龄(78±6)岁,全部为男性.以上受试对象均无甲状腺疾病病史,未用影响甲状腺功能的药物.清晨空腹安静状态下抽取静脉血2mL用放免法测定TT3,TT4,FT3,FT4及TSH,药盒由天津DPC公司提供.ABC3组TT3(nmol/L)和FT3(pmol/L)水平均减低,C组减低最明显,分别为1.7±0.4和3.9±0.9,1.3±0.4和… 相似文献
96.
0引言肾实质癌通常来源于肾小管上皮细胞的腺癌,透明细胞癌占85%,其余为颗粒细胞癌及混合细胞癌,常伴有出血、坏死、囊变和钙化[1-3].我们分析手术根治的肾实质癌组织病理情况并讨论临床意义. 相似文献
97.
A case of cerebellopontine angle epithelial cyst is described. Lesions in this region usually present with hearing loss, tinnitus, dysequilibrium, headaches, facial numbness and occasionally trigeminal neuralgia. Our patient presented with the unusual phenomenon of episodic facial palsy. The literature reporting this lesion as well as this mode of presentation has been reviewed. 相似文献
98.
FR Kaufman G Costin DW Thomas FR Sinatra TF Roe HB Neustein 《Archives of disease in childhood》1984,59(8):787-789
The diagnosis of optic nerve hypoplasia and hypopituitarism must be entertained in infants who present for evaluation of cholestatic jaundice, particularly if there is associated hypoglycaemia and wandering nystagmus. Although the hepatic dysfunction seems to resolve, the long term prognosis of liver disease in optic nerve hypoplasia remains unknown. 相似文献
99.
0 引言 甲型肝炎病毒 (HAV)是危害人类健康的致病原之一 ,目前已有多种用于接触前预防的甲肝疫苗 ;但对于接触后预防或短期到 HAV高流行区的旅游者的预防 ,则多采用免疫球蛋白作被动免疫 .在接触后 (14d内 )和潜伏期早期 ,注射免疫球蛋白预防甲肝的有效率达 85 %左右 .血源性免疫球蛋白虽然效价高 ,应用效果好 ,但可能被血源病原体污染 .因此基因工程人源抗体有望成为接触后预防的首选制剂 .我们从人源噬菌体抗体组合文库中筛选到一株甲肝特异性抗体 [1 ] ,在此基础上构建了可溶性表达载体 ,并获得可溶性表达 ,为该抗体的进一步研究打… 相似文献
100.
0 引言 骨形成蛋白 (Bone morphogenetic Proteins,BMPs)属于 TGF- β超家族 ,最初从牛的脱矿骨骨基质提取出来 ,在活体内可诱导异位成骨 .但近年来的研究表明 ,BMPs还是生长和发育中的调控分子 .为了探讨 BMPs在颅面部发育过程中的表达、区域及变化 ,为进一步研究颅面部畸形 (如腭裂、唇裂、牙齿发育畸形等 )的发生机制打下基础 ,作者检测了BMP2 ,4在颅面部各组织正常发育中的表达模式 .1 材料和方法1.1 材料 BAL B/ c近交系孕鼠在妊娠期第 14,15 ,16日分别被脱椎处死 ,取胎鼠头部固定于 40 g· L- 1多聚甲醛 ,常规脱水包埋… 相似文献