全文获取类型
收费全文 | 2795篇 |
免费 | 266篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 22篇 |
妇产科学 | 17篇 |
基础医学 | 230篇 |
口腔科学 | 8篇 |
临床医学 | 510篇 |
内科学 | 365篇 |
皮肤病学 | 60篇 |
神经病学 | 13篇 |
特种医学 | 488篇 |
外国民族医学 | 2篇 |
外科学 | 366篇 |
综合类 | 473篇 |
预防医学 | 73篇 |
眼科学 | 13篇 |
药学 | 87篇 |
中国医学 | 56篇 |
肿瘤学 | 291篇 |
出版年
2024年 | 18篇 |
2023年 | 55篇 |
2022年 | 139篇 |
2021年 | 198篇 |
2020年 | 175篇 |
2019年 | 132篇 |
2018年 | 134篇 |
2017年 | 126篇 |
2016年 | 153篇 |
2015年 | 150篇 |
2014年 | 248篇 |
2013年 | 182篇 |
2012年 | 145篇 |
2011年 | 171篇 |
2010年 | 133篇 |
2009年 | 100篇 |
2008年 | 142篇 |
2007年 | 140篇 |
2006年 | 105篇 |
2005年 | 77篇 |
2004年 | 77篇 |
2003年 | 64篇 |
2002年 | 25篇 |
2001年 | 32篇 |
2000年 | 23篇 |
1999年 | 30篇 |
1998年 | 24篇 |
1997年 | 12篇 |
1996年 | 20篇 |
1995年 | 21篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有3131条查询结果,搜索用时 15 毫秒
1.
Akira Mogi Toshiki Yajima Kenji Tomizawa Ryoichi Onozato Shigebumi Tanaka Hiroyuki Kuwano 《Annals of thoracic and cardiovascular surgery》2015,21(5):435-439
Purpose: Small pulmonary lesions that include ground-glass attenuation have been increasingly discovered because of progressive imaging diagnostic technologies. Despite the detection of such small lesions, sometimes it is quite difficult to localize them because of their size or considerable depth from the visceral pleura. In the present study, we examined the usefulness of computed tomography-guided lipiodol marking for thoracoscopic resection of impalpable pulmonary nodules.Methods: Fifty-six patients with an undiagnosed peripheral lesion(s) of the lung who had undergone preoperative computed tomography-guided lipiodol marking followed by video-assisted thoracoscopic surgery were studied.Results: All of the nodules were successfully marked by computed tomography-guided lipiodol marking, and all except for one case were localized by means of intraoperative fluoroscopy as clear spots. With regard to complications, pneumothorax occurred in 21 patients (37.5%), and only one patient required transient drainage. Although hemorrhaging in the lung parenchyma and hemosputum occurred in nine patients (16.1%) and one patient (1.8%), respectively, no patients were in serious condition. No intra- or postoperative mortality or morbidity was observed.Conclusion: Preoperative computed tomography-guided lipiodol marking of small or impalpable pulmonary nodules is a safe and useful procedure for thoracoscopic resection of the lung. 相似文献
2.
3.
目的:研究孤立性肺结节(SPN)胸腔镜术前CT引导下双弹簧圈精准标记定位的应用价值。方法:回顾分析43例SPN胸腔镜术前定位病例资料,包括双弹簧圈组22例,Hook-wire定位组21例。统计双弹簧圈定位的术中、术后并发症,衔接期时间以及作楔形切除所用时间,并将两组结果进行对比分析。结果:两组病例定位均取得成功;双弹簧圈组的气胸发生率(9.0%),肺出血发生率(9.0%),胸痛发生率(9.0%)均低于Hook-wire组,其中肺出血发生率与Hook-wire组比较,差异有统计学意义(P<0.01);衔接时间双弹簧圈组(15.38±8.32)h长于Hook-wire组(4.21±3.29)h,差异有统计学意义(P<0.05);作楔形切除所用时间双弹簧圈组(21.01±7.14)min与Hook-wire组(18.22±5.18)min差异无统计学意义(P>0.05)。结论:采用双微弹簧圈进行SPN胸腔镜手术前精准标记定位安全可靠、效果良好,与Hook-wire定位比较并发症发生率更低,并可获得更长的衔接期,具有较高的应用价值。 相似文献
4.
Marie Ohata Susumu Fujiwara Ai Yoshioka Hiroshi Nagai Shintaro Sugita Nozomi Yamano Yusuke Inoue Chikako Nishigori 《Pediatric dermatology》2019,36(6):997-998
Fibroblastic connective tissue nevus (FCTN) is a benign cutaneous mesenchymal lesion characterized by proliferation of CD34‐positive fibroblastic/myofibroblastic spindle‐shaped cells. We report a case of agminated FCTN on the right lower abdomen of a 1‐year‐old boy. 相似文献
5.
Rena Fushiki Kotoe Mayahara Mai Ogawa Yasuyo Takahashi Yoko Karasawa Niina Tsurumachi 《Connective tissue research》2015,56(4):336-341
Purpose: Orthodontic tooth movement occurs during the bone remodeling induced by therapeutic mechanical strain. It is important to investigate the relation between the strength of mechanical stress and bone formation activity. The aim of this study was to determine the effect of high-magnitude mechanical strain on bone formation in detail.Materials and methods: Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48?h. To phenotypically investigate the effect of TF, we measured the number and the size of bone nodules stained by von Kossa technique on day 21 after cell seeding and determined the calcium content of bone nodules on day 14. Furthermore, we examined the gene expression of BMP-2, Runx2 and Msx2, which are important factors for bone nodule formation, on days 1, 4 and 7 after TF loading.Results: The maximum bone nodule size in the control group was 1620 and 719?μm in the TF group. Furthermore, the mean number of bone nodules sized over 360?μm in the TF group was significantly decreased compared to the control group. The calcium content was also significantly decreased to 42% by TF loading. The mRNA expression of BMP-2, Runx2 and Msx2 was decreased 1 and 4 days after TF loading.Conclusion: The differentiation of bone forming progenitor cells into bone nodule forming cells was inhibited by TF due to the decreased expression of bone formation related factors such as BMP-2, Runx2 and Msx2. 相似文献
6.
肝硬化再生结节和退变结节的MRI表现:初步研究结果 总被引:11,自引:0,他引:11
目的研究肝硬化再生结节和退变结节的MRI表现.资料与方法前瞻性地研究26例肝硬化再生结节和退变结节的MRI表现,其中合并肝癌8例.26例中有12例行CT平扫,6例行CT增强扫描;26例均行MRI平扫,18例行Gd-DTPA增强MRI,10例行超顺磁性氧化铁(菲立磁)增强MVI.临床实验室检查中,除8例合并有肝癌的患者甲胎蛋白显著增高外,其余18例甲胎蛋白均正常.结果26例中12例结节灶直径<1 cm,8例在1~3 cm,6例>3 cm.MRI表现:12例直径<1 cm的结节灶在T1WI呈等信号,T2WI呈低信号,Gd-DTPA和菲立磁增强与正常肝实质呈同步强化,在CT上呈高密度改变.结节灶直径1~3 cm的8例中,5例结节在T1WI呈高信号,T2WI呈低信号,强化同前;另3例在T1WI呈低信号的结节,在T2WI呈高信号,其强化与正常肝实质不同步,在菲立磁增强扫描中呈高信号;CT平扫均呈等密度.6例直径>3 cm的结节中2例在T1WI、T2WI均呈等高信号,菲立磁增强扫描呈高信号,Gd-DTPA增强MRI示巨大结节较周围邻近正常肝组织信号高;4例在T1WI呈高信号,在T2WI呈低信号,菲立磁增强扫描呈低信号,Gd-DTPA增强扫描巨大结节无强化,较周围邻近正常肝组织信号低,有时可见血管经过巨大结节表面.CT显示6例呈等或稍高密度.在MRI上可见1例“结中结”征.结论肝硬化再生结节在MRI上能较好地与肝细胞癌鉴别,但较难与退变结节鉴别.退变结节在T2WI不呈高信号,而肝细胞癌呈高信号,以此可作区别.此外,良性退变结节菲立磁增强T2WI呈低信号. 相似文献
7.
8.
9.
M.B. McDermott A.C. Lind E.F. Marley L.P. Dehner 《Pediatric and developmental pathology》1998,1(4):300-308
Deep granuloma annulare (DGA) is one of several lesions of skin and superficial soft tissues whose histologic character is
a palisading granuloma with a small central focus of necrosis or necrobiosis. Unlike the other palisading necrobiotic lesions,
DGA has a predilection for children in the first 5 to 6 years of life. A painless subcutaneous nodule(s) in the lower anterior
tibial region or foot and the scalp, typically in the occiput, was the most common presenting feature in this study of 35
cases. Additional or recurrent lesions were reported in approximately 70% of cases with clinical follow-up. All lesions showed
the presence of necrobiosis; however, one of the characteristic features was the multinodular character of the predominantly
mononuclear cellular aggregates. The presence of vascular spaces at the periphery of the nodular profiles served as a clue
to the diagnosis of DGA. The palisading arrangement of the mononuclear cells was evident only in those foci with central necrobiosis.
A histiocytic disorder or fibrohistiocytic process was a common consideration in the differential diagnosis, especially in
those cases with less apparent foci of necrosis. Palisading histiocytes with prominent eosinophilic cytoplasm and some nuclear
atypism were problematic with regard to possible epithelioid sarcoma. Our study failed to identify any underlying or predisposing
factors in the development of DGA. Despite the fact that DGA is a well-documented lesion in children, it occurs sufficiently
infrequently that it is often not considered clinically when it presents as a subcutaneous mass or masses in a child. Its
recognition by the pathologist is especially important as the occurrence of additional lesions in a high proportion of children
can be anticipated without undue concern.
Received June 16, 1997; accepted October 28, 1997. 相似文献
10.
胸腔镜辅助小切口手术诊治肺周围型结节 总被引:10,自引:3,他引:7
目的探讨胸腔镜辅助小切口手术在诊断和治疗肺周围型结节病变中的临床应用价值。方法胸腔镜辅助小切口手术诊治肺周围型结节55例,其中单发结节54例,多发结节1例。肺楔形切除术23例;肺叶切除联合淋巴结清扫治疗原发性肺癌32例,采用常规开胸手术器械及胸腔镜用器械切除肺叶,自制淋巴结摘除钳完成淋巴结清扫。结果55例均在胸腔镜下完成手术。手术时间35~180min,平均109min,术中出血量50~400ml,平均122min。均未输血,1例术后漏气术后32d出院,1例切口延迟愈合,术后19d出院,余53例术后住院4~11d,平均8.3d。无严重并发症。术后病理:良性病变15例,原发性肺癌38例,非典型性腺瘤样增生1例,转移性肺癌1例。良性病变行肺楔形切除术,32例原发性肺癌行解剖学肺叶切除联合淋巴结清扫,4例肺癌胸膜广泛播散未手术处理,2例肺癌因肺功能差行姑息性肺楔形切除。结论胸腔镜辅助小切口手术有助于明确诊断肺周围型结节病变,治疗临床早期原发性肺癌的长期疗效有待随访观察。 相似文献