全文获取类型
收费全文 | 35660篇 |
免费 | 3143篇 |
国内免费 | 677篇 |
专业分类
耳鼻咽喉 | 571篇 |
儿科学 | 1065篇 |
妇产科学 | 2038篇 |
基础医学 | 2067篇 |
口腔科学 | 690篇 |
临床医学 | 3193篇 |
内科学 | 3806篇 |
皮肤病学 | 414篇 |
神经病学 | 5164篇 |
特种医学 | 586篇 |
外国民族医学 | 4篇 |
外科学 | 5848篇 |
综合类 | 3250篇 |
一般理论 | 1篇 |
预防医学 | 2276篇 |
眼科学 | 4594篇 |
药学 | 1916篇 |
23篇 | |
中国医学 | 397篇 |
肿瘤学 | 1577篇 |
出版年
2024年 | 52篇 |
2023年 | 790篇 |
2022年 | 1047篇 |
2021年 | 1929篇 |
2020年 | 1792篇 |
2019年 | 1827篇 |
2018年 | 1731篇 |
2017年 | 1593篇 |
2016年 | 1520篇 |
2015年 | 1398篇 |
2014年 | 2577篇 |
2013年 | 2985篇 |
2012年 | 1918篇 |
2011年 | 1964篇 |
2010年 | 1650篇 |
2009年 | 1582篇 |
2008年 | 1580篇 |
2007年 | 1500篇 |
2006年 | 1387篇 |
2005年 | 1229篇 |
2004年 | 1035篇 |
2003年 | 884篇 |
2002年 | 732篇 |
2001年 | 617篇 |
2000年 | 484篇 |
1999年 | 386篇 |
1998年 | 376篇 |
1997年 | 288篇 |
1996年 | 212篇 |
1995年 | 228篇 |
1994年 | 168篇 |
1993年 | 181篇 |
1992年 | 164篇 |
1991年 | 159篇 |
1990年 | 120篇 |
1989年 | 138篇 |
1988年 | 102篇 |
1987年 | 91篇 |
1986年 | 113篇 |
1985年 | 189篇 |
1984年 | 164篇 |
1983年 | 129篇 |
1982年 | 116篇 |
1981年 | 103篇 |
1980年 | 92篇 |
1979年 | 41篇 |
1978年 | 33篇 |
1977年 | 26篇 |
1976年 | 22篇 |
1974年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 781 毫秒
71.
目的 :探讨玻璃体切割术前 F- ERG与术后视力的关系。方法 :对 5 0例行玻璃体切割手术的患者进行术前 F- ERG的测定 ,术后 2周对其视力进行测定 ,利用 SPSS软件包进行统计学处理。结果 :术前 F- ERG的 a波振幅与术后视力呈正相关 ;术前 F- ERG的 b波振幅与术后视力呈正相关 ;E值 ( E=La+ Lb/Aa+ Ab)与术后视力呈负相关 ;E小于等于 3.0者与 E大于 3.0组术后视力差异有显著性 ( P<0 .0 0 5 )。结论 :玻璃体切割术前进行正确的 F- ERG分析 ,有助于玻璃体切割术后视力的预测。 相似文献
72.
Figure-Ground Segregation at Contours: a Neural Mechanism in the Visual Cortex of the Alert Monkey 总被引:1,自引:0,他引:1
An important task of vision is the segregation of figure and ground in situations of spatial occlusion. Psychophysical evidence suggests that the depth order at contours is defined early in visual processing. We have analysed this process in the visual cortex of the alert monkey. The animals were trained on a visual fixation task which reinforced foveal viewing. During periods of active visual fixation, we recorded the responses of single neurons in striate and prestriate cortex (areas V1, V2, and V3/V3A). The stimuli mimicked situations of spatial occlusion, usually a uniform light (or dark) rectangle overlaying a grating texture of opposite contrast. The direction of figure and ground at the borders of these rectangles was defined by the direction of the terminating grating lines (occlusion cues). Neuronal responses were analysed with respect to figure-ground direction and contrast polarity at such contours. Striate neurons often failed to respond to such stimuli, or were selective for contrast polarity; others were non-selective. Some neurons preferred a certain combination of figure-ground direction and contrast polarity. These neurons were rare both in striate and prestriate cortex. The majority of neurons signalled figure-ground direction independent of contrast polarity. These neurons were only found in prestriate cortex. We explain these responses in terms of a model which also explains neuronal signals of illusory contours. These results suggest that occlusion cues are used at an early level of processing to segregate figure and ground at contours. 相似文献
73.
J.I. Smedberg E. Lothigius I. Bodin A. Frykholm K. Nilner 《Clinical oral implants research》1993,4(1):39-46
In order to satisfy the need to restore the aesthetics, phonetics and comfort and to facilitate optimal hygiene procedures, 20 edentulous patients were treated with a new concept of overdenture therapy on implants ad modum Brånemark. After 24±3.5 months the patients were re‐examined. They were asked to answer a questionnaire and use a Visual Analogue Scale (VAS) to give their opinion on the prosthetic treatment. The results indicate that an implant‐retained overdenture in the maxilla with this design can satisfy the patients needs in aesthetics, phonetics and comfort and can 1 facilitate oral hygiene measures. 相似文献
74.
Yuji Morimoto Osamu Kemmotsu Koichi Kitami Izumi Matsubara Ichiro Tedo 《Journal of anesthesia》1995,9(1):22-26
We evaluated whether we could predict the neurologic outcome in 55 out-of-hospital cardiac arrest patients using auditory
brainstem responses (ABR). ABR patterns were classified into one of 3 types by evaluation of 5 components: type 1, with all
5 components; type 2, lack of at least one response between the 2nd and 5th components; type 3, with only the first component
or no response. The relation between the ABR patterns on the 3rd day following resuscitation and the neurologic outcome on
hospital discharge was evaluated. The specificity that the 5 awake patients had type-1 ABR was 38%. The sensitivity that the
10 brain dead patients had type-3 ABR was 60%. In the type-1 ABR patients, the negative predictive value that the patients
were awake was 100%. In the type-3 ABR patients, the negative predictive value that the patients became brain dead was 90.9%.
These results suggest that ABR on the 3rd post-resuscitation day may not be useful for predicting if patients are awake or
become brain dead, although the loss of components may be a sign of morbidity, and the presence of the 2nd or later components
indicates possible future prevention of brain death. 相似文献
75.
目的:探讨苦碟子注射液治疗突发性聋的效果。方法:随机将120例患者分为两组,治疗组60例,予以苦碟子注射液治疗;对照组60例,予以低分子右旋糖酐联合复方丹参注射液治疗。结果:治疗组治疗耳聋、耳鸣总有效率分别为88.33%、82.86%,对照组分别为68.33%、62.50%,治疗组耳聋、耳鸣总有效率均明显高于对照组(P<0.05)。结论:苦碟子注射液治疗突发性聋疗效好且安全可靠,无明显不良反应。 相似文献
76.
Ho-Seong Han Jai Young Cho Yoo-Seok Yoon 《Journal of hepato-biliary-pancreatic sciences》2009,16(4):427-432
Many studies have recently reported on laparoscopic liver resection, although its development has been slow compared to laparoscopy in other fields. The indications for the location of laparoscopic liver resection have previously been limited to easily accessible lesions. Performing laparoscopic liver resection in the posterior and superior parts of the liver has been considered difficult due to inadequate exposure, the poor operative field and the difficulty with parenchymal dissection. Flexible endoscopy, high definition imaging and various kinds of equipment for parenchymal transection have been introduced for clinical use. In addition, much experience with this procedure has been accumulated at many centers. Accordingly, there are an increasing number of reports on laparoscopic liver resection in difficult locations. At our institution, the location of the tumor is no longer a limitation to laparoscopic liver resection. However, for safer laparoscopic liver resection, the patient positioning and trocar placement should be individualized according to the tumor location. The type of resection also may depend on the remaining liver’s functional capacity. We describe here the technical considerations for performing laparoscopic liver resection, including the technical considerations for performing laparoscopic liver resection for lesions located in the postero-superior segments of the liver. 相似文献
77.
目的 探讨不同年龄段、恶性程度不同的多节段髓内星形细胞瘤患者的诊治特点.方法 21例多节段(3个椎体节段以上)髓内星形细胞瘤患者均行后正中入路显微镜下肿瘤切除术,以UOA分值差(术后UOA和术前UOA差值)评估手术效果.以Logistic回归和多元线性同归分析统计学数据.结果 肿瘤性质直接影响肿瘤的切除程度(X2=10.41,P=0.03),高度恶性肿瘤只能大部切除或减压.年龄(X2=12.53,P=0.01)、肿瘤性质(X2=16.44,P=0.002)和部位(X2=27.12,P=0.04)影响近期手术效果(UOA分值差);青少年患者、低度恶性肿瘤手术效果较好,单纯累及胸段的患者手术效果差.结论 低度恶性或青少年多节段髓内星形细胞瘤患者应尽早手术,术后疗效满意. 相似文献
78.
L. J. Jacobsson M. Westerberg S. Söderberg J. Lexell 《Acta neurologica Scandinavica》2009,120(6):389-395
Objectives – To assess long‐term functioning and disability after traumatic brain injury (TBI). Material and methods – Individuals (n = 88) in Norrbotten, northern Sweden, who had been transferred for neurosurgical care were assessed with internationally established TBI outcome measures 6–15 years post‐injury. Results – There was an improvement in overall outcome from discharge from inpatient rehabilitation to follow‐up. Many individuals had a high degree of motor and cognitive functioning, which enabled them to live independently in their own home without assistance, but there remained a disability related to community reintegration and social participation. This affected their productivity and to some degree their marital stability. The remaining disability and reduced productivity were related to the age at injury and the injury severity. Conclusions – Our data showed that individuals with a TBI can achieve and maintain a high degree of functioning many years after the injury. Increasing age and a greater injury severity contributed to their long‐term disability. 相似文献
79.
人胎视网膜发生的光镜和电镜观察 总被引:3,自引:0,他引:3
本文在光镜下观察40例人胎视网膜的发生,在电镜下观察15例人胎视网膜视细胞、双极细胞、节细胞的发育。结果表明:胚胎第9周时神经上皮可分内、外成神经细胞层。第10周时内、外成神经细胞层之间的Chievitz带消失;第11周时节细胞从内成神经细胞层内迁;第13周节细胞与内成神经细胞之间出现内网层;第16周始双极细胞从外成神经细胞层中内迁形成外网层和内核层。第20周后视网膜各层形成。而视细胞、双极细胞、节细胞的超微结构于胎儿8个月后才发育完善。其结构与成人基本相同。 相似文献
80.