全文获取类型
收费全文 | 96328篇 |
免费 | 7031篇 |
国内免费 | 2565篇 |
专业分类
耳鼻咽喉 | 569篇 |
儿科学 | 807篇 |
妇产科学 | 556篇 |
基础医学 | 6621篇 |
口腔科学 | 1647篇 |
临床医学 | 9525篇 |
内科学 | 9512篇 |
皮肤病学 | 1726篇 |
神经病学 | 3573篇 |
特种医学 | 2769篇 |
外国民族医学 | 12篇 |
外科学 | 6682篇 |
综合类 | 18655篇 |
现状与发展 | 8篇 |
预防医学 | 9410篇 |
眼科学 | 1385篇 |
药学 | 17715篇 |
513篇 | |
中国医学 | 8697篇 |
肿瘤学 | 5542篇 |
出版年
2024年 | 104篇 |
2023年 | 1088篇 |
2022年 | 1890篇 |
2021年 | 3146篇 |
2020年 | 3024篇 |
2019年 | 4571篇 |
2018年 | 4189篇 |
2017年 | 3528篇 |
2016年 | 3508篇 |
2015年 | 3561篇 |
2014年 | 7570篇 |
2013年 | 7023篇 |
2012年 | 6055篇 |
2011年 | 5944篇 |
2010年 | 5055篇 |
2009年 | 5130篇 |
2008年 | 4106篇 |
2007年 | 5074篇 |
2006年 | 4495篇 |
2005年 | 3731篇 |
2004年 | 2388篇 |
2003年 | 2417篇 |
2002年 | 2011篇 |
2001年 | 1836篇 |
2000年 | 1480篇 |
1999年 | 1256篇 |
1998年 | 1080篇 |
1997年 | 910篇 |
1996年 | 840篇 |
1995年 | 826篇 |
1994年 | 742篇 |
1993年 | 555篇 |
1992年 | 559篇 |
1991年 | 507篇 |
1990年 | 428篇 |
1989年 | 412篇 |
1988年 | 381篇 |
1987年 | 363篇 |
1986年 | 325篇 |
1985年 | 627篇 |
1984年 | 632篇 |
1983年 | 437篇 |
1982年 | 432篇 |
1981年 | 340篇 |
1980年 | 330篇 |
1979年 | 246篇 |
1978年 | 158篇 |
1977年 | 165篇 |
1976年 | 131篇 |
1975年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Diabetic foot ulcer is a devastating complication of diabetes mellitus and significant cause of mortality and morbidity all over the world and can be complex and costly. The development of foot ulcer in a diabetic patient has been estimated to be 19%-34% through their lifetime. The pathophysiology of diabetic foot ulcer consist of neuropathy, trauma and, in many patients, additional peripheral arterial disease. In particular, diabetic neuropathy leads to foot deformity, callus formation, and insensitivity to trauma or pressure. The standard algorithms in diabetic foot ulcer management include assessing the ulcer grade classification, surgical debridement, dressing to facilitate wound healing, off-loading, vascular assessment (status and presence of a chance for interventional vascular correction), and infection and glycemic control. Although especially surgical procedures are sometimes inevitable, they are poor predictive factors for the prognosis of diabetic foot ulcer. Different novel treatment modalities such as nonsurgical debridement agents, oxygen therapies, and negative pressure wound therapy, topical drugs, cellular bioproducts, human growth factors, energy-based therapies, and systematic therapies have been available for patients with diabetic foot ulcer. However, it is uncertain whether they are effective in terms of promoting wound healing related with a limited number of randomized controlled trials. This review aims at evaluating diabetic foot ulcer with regard to all aspects. We will also focus on conventional and novel adjunctive therapy in diabetic foot management. 相似文献
2.
目的探讨前瞻性护理干预在急性心力衰竭患者中的应用效果。方法选取2018年4月—2020年5月河南省某医院收治的122例急性心力衰竭患者为研究对象,采用随机数字表法分为观察组与对照组,每组61例。对照组患者采用常规护理,观察组患者采用前瞻性护理,比较2组患者的干预效果、并发症发生情况,干预前后焦虑自评量表(SAS)、抑郁自评量表(SDS)评分及护理满意度。结果观察组患者干预总有效率为95.08%,高于对照组的75.41%,差异有统计学意义(χ2=9.385,P=0.002)。观察组患者并发症发生率为3.28%,低于对照组的18.03%,差异有统计学意义(χ2=6.974,P=0.008)。2组患者干预后SAS及SDS评分均低于干预前,且观察组低于对照组,差异均有统计学意义(P<0.05)。观察组患者护理满意度为98.36%,高于对照组的86.89%,差异有统计学意义(χ2=4.319,P=0.038)。结论前瞻性护理干预用于急性心力衰竭患者,有助于改善患者负性情绪及减少并发症的发生。 相似文献
3.
目的 评价美国国家电器制造协会(National Electrical Manufactures Association, NEMA)最新标准(NU 2-2018)在正电子发射型计算机断层显像/电子计算机断层显像(positron emission tomography/computed tomography, PET/CT)设备性能检测中的作用。 方法 依据最新的NEMA NU 2-2018标准,检测西门子Biograph Vision PET/CT的空间分辨率、灵敏度、散射分数、计数丢失、随机符合、飞行时间分辨率、计数丢失率和随机符合校正精度、图像质量、衰减和散射校正精度及PET与CT配准精度指标。 结果 距视野中心1 cm处横向和轴向空间分辨率分别为3.75 mm和3.76 mm;在视野中心和轴向10 cm处的灵敏度分别为16.83 kcps/MBq和16.67 kcps/MBq;放射性浓度为27.37 kBq/mL时,最大等效噪声计数率为258.26 kcps,散射分数为38.58%;系统时间分辨率为209.82 ps;图像质量模型的对比度恢复系数范围为88.9%~96.2%,背景变异系数范围为2.05%~6.80%,平均肺插件残余误差为2.43%;计数丢失和随机符合校正最大误差为3.9%;距离床板末端 5 cm 和 100 cm处,在距视野中心Y轴1 cm处,PET和CT的配准精度分别为0.46 mm和1.07 mm,在距视野中心X轴20 cm处,PET和CT的配准精度分别为1.06 mm和1.45 mm,在距视野中心Y轴20 cm处PET和CT的配准精度分别为0.85 mm和1.15 mm。 结论 NEMA NU 2-2018标准检测条件更加接近临床,能更好地反映PET/CT设备的系统性能。 相似文献
4.
PurposeOptical coherence tomography angiography (OCTA) was utilized to examine changes in ocular surface squamous neoplasia (OSSN) vascular patterns over time in individuals treated with topical medical therapy.MethodsTen individuals with OSSN diagnosed by clinical examination and high resolution (HR)-optical coherence tomography (OCT) were recruited. All individuals received topical immuno- or chemotherapy. OCTA images were obtained and analyzed at three points: presentation, mid-treatment and tumor resolution. Tumor metrics including tumor area (TA), tumor volume (TV), tumor depth (TD), and total tumor density (TTD) were calculated. Vessel area density (VAD) was also quantified within the OSSN, the subepithelium under and adjacent to the OSSN and the subepithelium of the uninvolved, contralateral eye. Vascular network changes were also subjectively evaluated.ResultsTA, TV, TD and TTD all significantly decreased with time (p < 0.001). The mean VAD within the OSSN significantly decreased (p < 0.001) between visits (presentation: 26.52 ± 6.8%, mid-treatment: 7.19 ± 5.88%, tumor resolution: 0.11 ± 0.34%). The mean subepithelial VAD under the OSSN also decreased with time (23.22 ± 11.03%, 20.99 ± 5.99% and 19.58 ± 7.08%), and after resolution the sub-tumor VAD (19.58 ± 7.08%) was comparable to the subepithelial VAD in the contralateral eye (15.47 ± 4.37%, p > 0.05). The mean VAD in the subepithelium adjacent to the OSSN increased with treatment, then decreased significantly between mid-treatment and resolution (23.26 ± 4.54, 28.30 ± 7.43% and 21.68 ± 6.10%, p = 0.009). Qualitatively, the tumor subepithelial vascular network was complex and dense but with tumor resolution appeared less tortuous and similar to the uninvolved eye.ConclusionOCTA provided insight into the pathophysiology of tumor angiogenesis, showing decreased vascular density and normalization of vascular networks associated with tumor resolution. 相似文献
5.
Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the “anti-biotic era”. Although, we have expeditiously developed our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts required for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins.In this review article, we provide an overview of the established diagnostic techniques and therapeutics for keratitis caused by various bacteria. We extensively report the recent in-roads through novel tools for accurately diagnosing mono- and poly-bacterial corneal infections. Furthermore, we outline the recent progress by our groups and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discuss in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis. 相似文献
6.
7.
目的:研究不同手术方法治疗儿童基本型外斜视与术后侧转非共同性发生及矫正效果相关性。
方法:回顾性研究。选取2018-06/2020-12于我院眼科接受治疗的180例基本型外斜视患儿临床资料。根据手术方式分为单眼一退一截术组(R&R组)104例和双眼外直肌后徙术组(BLR-rec组)76例。比较两组患者一般资料、手术矫正效果,以及随访期间手术斜视度数、侧转非共同性发生情况。
结果:两组患者术后3d,1、6mo视近、视远斜视度比较均无差异(均P>0.05)。R&R组术后不同时间点正位率高于BLR-rec组(P<0.05)。R&R组较BLR-rec组发生侧转非共同性的风险更低(OR=0.524, Wald χ2=4.260, P=0.039)。两组患者术后6mo主要表现在水平直肌手术眼外展方向注视,但两组患儿视远和视近侧转非共同性发生率均无差异(均P>0.05)。
结论:R&R对于儿童基本型外斜视的矫正效果优于BLR-rec术式,可降低侧转非共同性发生情况。 相似文献
8.
目的探讨慢性泪囊炎患者应用鼻内镜下鼻腔泪囊造口术的临床效果及安全性。方法选取2018年1月至2019年12月因慢性泪囊炎于本院接受治疗的46例患者为研究对象,随机分为研究组与对照组,各23例。对照组接受泪囊鼻腔造口治疗,研究组取鼻内镜下鼻腔泪囊造口术治疗,比较两组临床效果、手术指标以及并发症发生情况。结果研究组治疗总有效率高于对照组(P<0.05);研究组术中出血量少于对照组,手术及住院时间均短于对照组(P<0.05);研究组并发症总发生率低于对照组(P<0.05)。结论慢性泪囊炎患者采用鼻内镜下鼻腔泪囊造口术治疗效果显著,并发症较少,安全性较高,值得临床推广应用。 相似文献
9.
Melanie Y. T. Chan Arbab Anwar William J. S. Lockley 《Journal of labelled compounds & radiopharmaceuticals》2022,65(4):101-111
Base catalysed exchange with sodium hydroxide, calcium oxide or N,N,N,N-tetramethylguanidine in deuterium oxide is a viable procedure for the preparation of terminally deuterated alkynes for those alkynes stable to strong base. The use of silver perchlorate as a catalyst is an alternative practical option when labelling alkynes which are sensitive to base or contain functionalities which would lead to labelling elsewhere in the molecule. Labelling with this catalyst takes place smoothly at ambient temperature in a mixture of N,N-dimethylformamide and deuterium oxide. 相似文献
10.
目的探讨ω-3多不饱和脂肪酸(ω-3 poly unsaturated fatty acids,ω-3 PUFAs)对慢性移植物抗宿主病(chronic graft versus host disease,cGVH)狼疮模型小鼠的免疫调节功能影响。方法单次腹腔注射bm12小鼠淋巴细胞建立cGVH小鼠模型,造模当天分别给予90%ω-3 PUFAs和97%EPA灌胃治疗,持续14 d。通过流式细胞术检测小鼠脾脏淋巴细胞中各免疫指标,ELISA检测小鼠血清中总IgG水平。结果与正常对照组相比,cGVH组明显下调Treg亚群,明显上调TFH细胞、生发中心B细胞和浆细胞亚群;与模型对照组相比,90%ω-3和97%EPA均明显上调Treg亚群,并明显下调TFH细胞、生发中心B细胞和浆细胞亚群;且97%EPA组小鼠血清中总IgG水平明显下降。结论在cGVH狼疮小鼠模型中,ω-3 PUFAs通过增加Treg细胞,减少TFH细胞、生发中心B细胞和浆细胞,抑制IgG的分泌,从而发挥免疫抑制作用,且其免疫抑制作用可能与ω-3 PUFAs含量相关。 相似文献