全文获取类型
收费全文 | 190899篇 |
免费 | 1776篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 1293篇 |
儿科学 | 6960篇 |
妇产科学 | 3329篇 |
基础医学 | 18256篇 |
口腔科学 | 2962篇 |
临床医学 | 13356篇 |
内科学 | 34943篇 |
皮肤病学 | 1082篇 |
神经病学 | 17697篇 |
特种医学 | 9155篇 |
外科学 | 31001篇 |
综合类 | 2391篇 |
一般理论 | 4篇 |
预防医学 | 19207篇 |
眼科学 | 3086篇 |
药学 | 10101篇 |
中国医学 | 704篇 |
肿瘤学 | 17240篇 |
出版年
2023年 | 131篇 |
2022年 | 276篇 |
2021年 | 585篇 |
2020年 | 334篇 |
2019年 | 540篇 |
2018年 | 22439篇 |
2017年 | 17690篇 |
2016年 | 19847篇 |
2015年 | 1394篇 |
2014年 | 1497篇 |
2013年 | 1610篇 |
2012年 | 8295篇 |
2011年 | 22429篇 |
2010年 | 19584篇 |
2009年 | 12163篇 |
2008年 | 20543篇 |
2007年 | 22888篇 |
2006年 | 1602篇 |
2005年 | 3089篇 |
2004年 | 4176篇 |
2003年 | 4996篇 |
2002年 | 3166篇 |
2001年 | 338篇 |
2000年 | 455篇 |
1999年 | 221篇 |
1998年 | 302篇 |
1997年 | 290篇 |
1996年 | 164篇 |
1995年 | 148篇 |
1994年 | 147篇 |
1993年 | 99篇 |
1992年 | 59篇 |
1991年 | 103篇 |
1990年 | 143篇 |
1989年 | 84篇 |
1988年 | 66篇 |
1987年 | 49篇 |
1986年 | 32篇 |
1985年 | 40篇 |
1984年 | 44篇 |
1983年 | 39篇 |
1982年 | 35篇 |
1980年 | 59篇 |
1974年 | 25篇 |
1970年 | 24篇 |
1938年 | 61篇 |
1937年 | 25篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
3.
4.
5.
6.
7.
Andres Eduardo Campuzano-García Bertha Torres-Alvarez Diana Hernández-Blanco 《Journal of cosmetic and laser therapy》2015,17(4):213-215
Hailey–Hailey disease (HHD), also known as benign familial pemphigus, is an autosomal dominant skin condition that affects the adhesion of epidermal keratinocytes. Although the initial manifestation of flaccid vesicles on erythematous or normal skin in flexure sites frequently goes unnoticed, large, macerated, exudative plaques of superficial erosions with crusting are observed at the time of diagnosis. There is no specific treatment for HHD, and most cases are symptomatically supported. However, infrared laser ablation has been somewhat helpful. We present a case successfully treated with fractional CO2 laser showing a long-term favourable outcome and no adverse effects. Thus, this modality could be an alternative to full ablation for this condition. 相似文献
8.
Alejandra Gordillo Hernández Eduardo Dominguez-Adame Lanuza Auxiliadora Cano Matias Rosario Perez Huertas Katherine Maria Gallardo Rodriguez Purificacion Gallinato Perez Fernando Oliva Mompean 《World journal of gastrointestinal surgery》2015,7(8):170-173
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence. 相似文献
9.
10.