全文获取类型
收费全文 | 3635篇 |
免费 | 218篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 94篇 |
妇产科学 | 98篇 |
基础医学 | 198篇 |
口腔科学 | 180篇 |
临床医学 | 437篇 |
内科学 | 526篇 |
皮肤病学 | 80篇 |
神经病学 | 140篇 |
特种医学 | 134篇 |
外科学 | 619篇 |
综合类 | 445篇 |
一般理论 | 1篇 |
预防医学 | 252篇 |
眼科学 | 86篇 |
药学 | 238篇 |
5篇 | |
中国医学 | 167篇 |
肿瘤学 | 112篇 |
出版年
2024年 | 10篇 |
2023年 | 29篇 |
2022年 | 60篇 |
2021年 | 114篇 |
2020年 | 81篇 |
2019年 | 58篇 |
2018年 | 85篇 |
2017年 | 85篇 |
2016年 | 73篇 |
2015年 | 101篇 |
2014年 | 131篇 |
2013年 | 200篇 |
2012年 | 251篇 |
2011年 | 271篇 |
2010年 | 211篇 |
2009年 | 213篇 |
2008年 | 285篇 |
2007年 | 318篇 |
2006年 | 337篇 |
2005年 | 228篇 |
2004年 | 163篇 |
2003年 | 176篇 |
2002年 | 135篇 |
2001年 | 74篇 |
2000年 | 69篇 |
1999年 | 39篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 17篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 14篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1977年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有3944条查询结果,搜索用时 0 毫秒
81.
The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1-7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Phe- amide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway. 相似文献
82.
Ahmet Yalcin Gungor Erhan Ozcan Huseyin Alkis Hakan Turkkahraman 《The Angle orthodontist》2013,83(4):686
Objective:To evaluate the effects of different bleaching methods on the shear bond strength (SBS) of orthodontic brackets.Materials and Methods:Forty-five freshly extracted premolars were randomly divided into three groups (n = 15 per group). In group I, bleaching was performed with the office bleaching method. In group II, bleaching was performed with the home bleaching method. Group III served as the control. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets were tested with a Universal testing machine.Results:Analysis of variance indicated a significant difference between groups (P < .001). The highest values for SBS were measured in group III (20.99 ± 2.32 MPa). The SBS was significantly lower in groups I and II than in group III (P < .001). The lowest values for SBS were measured in group II (6.42 ± 0.81 MPa). SBS was significantly higher in group I than in group II (P < .001).Conclusions:Both of the bleaching methods significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with the home bleaching method affected SBS more adversely than did bleaching with the office bleaching method. 相似文献
83.
Background
The understanding and management of transverse intra‐alveolar root fractures has evolved to its current high level of sophistication and clinical success from foundations laid down by histological studies as early as the mid‐nineteenth century.Significance
The aim of the review was to highlight those earlier histological reports and studies that have contributed to the current understanding of the biological processes involved in the healing of transverse root fractures. Healing of a transverse root fracture by calcified tissue was demonstrated histologically by Howe in 1926, while Boulger in 1928 showed the two other patterns of root fracture healing, namely the interposition of fibrous connective tissue and the interposition of bone and periodontal ligament around both fractured segments. Other major histological reports around that time came from members of the so‐called ‘The Vienna group of Illinois’, who had a significant influence in the development of oral biology worldwide. Other important reports and an experimental study emanated from Germany and Switzerland in the late 30s and early 40s, followed in the 1950s and early 1960s by histological material principally from Sweden, Denmark, France, the USA and Britain. Jens Andreasen and Erik Hjörting‐Hansen's landmark paper in 1967 included new histological reports and a classification of healing responses following transverse root fractures. The expansion of knowledge related to root fractures since that time has been exponential, with major contributions from Scandinavia and several other countries.Case reports
Accompanying the historical review are two case reports with histology of root fracture healing by (a) calcified tissue and (b) dense fibrous connective tissue. The role of the pulp and the periodontal ligament in the repair process is described and the clinical significance discussed with particular emphasis to diagnosis and orthodontic management. 相似文献84.
M.A. Adibelli A.H. Ozcan K. Kismet S. Erel B. Kilicoglu A. Gollu 《Acta chirurgica Belgica》2013,113(5):578-580
Purpose: To evaluate the effect of PVP-I liposome hydrogel on intraperitoneal postoperative adhesions. Material and Methods: Thirty Wistar-Albino male rats were randomly divided into three groups. After midline laparotomy, a 1 cm2 area of the caecum was abraded with a sterile gauze until subserosal haemorrhage had developed. A 1 χ 1 cm patch of peritoneum located opposite of caecal abrasion was completely dissected. In group 1 (control group, C) adhesion induction was performed and nothing was applied to the wounds. In group 2 and 3, PVP-I solution (3%) (group 2, PI) and PVP-I liposome hydrogel (group 3, PIL) were applied to the caecal abrasion areas and peritoneal defects. Adhesions were classified according to a classification system based on the evaluation of the appearance, extent and strength of the adhesions on postoperative 21st day.Results: There was no significant difference of the adhesion scores between the groups (U1 = 45, p > 0.05; U2 = 48, p > 0.05; U3 = 47.5, p > 0.05).Conclusions: We found that PVP liposome hydrogel did not influence postoperative intraabdominal adhesions and should be further explored for its potential use in various intraabdominal procedures. 相似文献
85.
上皮样血管内皮瘤(epithelioid hemangioendothelioma,EHE)是一种病因及发病机制不明,累及单个或多个器官的血管源性肿瘤,具有低至中度恶性潜能,呈慢性进行性发展过程.肝脏是EHE受累的常见器官之一.Ishak等[1]在1984年首次报道了肝上皮样血管内皮瘤(hepatic epithelioid hemangioendothelioma,HEHE),此后相关报道逐渐增多.影像学检查是诊断HEHE常用的手段之一,如螺旋X线计算机断层摄影术(CT)、磁共振成像(MRI)、核医学检查等,但存在一定的局限性.我们在此报道1例病史长达17年的HEHE患者的肝脏CT灌注特点及其在HEHE诊断中的价值. 相似文献
86.
Gurcan Dogukan Arslan Dilek Guven Mehmet Demir Abdurrahman Alpaslan Alkan Delil Ozcan 《Indian journal of ophthalmology》2021,69(5):1189
Purpose:The aim of this study was to evaluate the structural and functional changes occurring in patients with branch retinal vein occlusion (BRVO) according to the distance of the affected arteriovenous (AV) crossing to the centers of the fovea and optic disc by optic coherence tomography angiography (OCTA).Methods:Forty-five patients with unilateral BRVO and 45 age- and sex-matched healthy controls were included in this retrospective observational study. Images of the macula (3 mm × 3 mm) and affected AV crossing sites were obtained by OCTA. The fovea-AV crossing distance (FAVD), optic disc-AV crossing distance (DAVD), and optic disc-fovea distance (DFD) were measured.Results:The FAVD/DFD ratio was positively correlated with the vessel density in the superficial and deep affected hemifields (r = 0.430, P < 0.05 and r = 0.308, P < 0.05, respectively) and negatively correlated with the superficial foveal avascular zone and logarithm of the minimum angle of resolution (logMAR) visual acuity (r = –0.412, P < 0.05 and r = –0.356, P < 0.05, respectively). The DAVD/DFD ratio was not correlated with the logMAR visual acuity, superficial FAZ area or vessel densities in the affected hemifield (all P > 0.05).Conclusion:The affected AV crossing site that was further away from the fovea had better visual acuity and quantitative microvascular parameters in the affected hemifields. However, this correlation was not observed for the distance between the affected AV crossing site and the optic disc. 相似文献
87.
88.
Muhammet Fuat Ozcan Omer Dizdar Nazmiye Dincer Serdar Balcı Gulnur Guler Bahri Gok Gokhan Pektas Mehmet Metin Seker Sercan Aksoy Cagatay Arslan Suayib Yalcin Mevlana Derya Balbay 《Urologic oncology》2013,31(8):1709-1715
PurposeExcision repair cross-complementation group 1 enzyme (ERCC1) plays a key role in the removal of platinum induced DNA adducts and cisplatin resistance. Prognostic role of ERCC1 expression in the neoadjuvant setting in bladder cancer has not been reported before. We evaluated the prognostic role of ERCC1 expression in bladder cancer receiving platinum-based neoadjuvant chemotherapy.Materials and methodsThirty-eight patients with muscle invasive bladder cancer who received neoadjuvant platinum-based chemotherapy were included. Clinical and histopathologic parameters along with immunohistochemical ERCC1 staining were examined and correlated with response rates and survival.ResultsPathologic complete response rates were similar between patients with low and high ERCC1 expression. Median disease-free survival (DFS) was 9.3 vs. 20.5 months (P = 0.186) and median overall survival (OS) was 9.3 vs. 26.7 months (P = 0.058) in patients with high ERCC1 expression compared with those with low expression, respectively. In multivariate Cox regression analysis: pathological complete response (pCR) after chemotherapy (hazard ratio (HR) 0.1, 95% CI 0.012–0.842, P = 0.034) and high ERCC1 expression (HR 3.7, 95% CI 1.2–11.2, P = 0.019) were significantly associated with DFS. Patient age (>60 vs. ≤60 years) (HR 3.4, 95% CI 1.2–9.4, P = 0.018), the presence of pCR (HR 0.11, 95% CI 0.014–0.981, P = 0.048) and high ERCC expression (HR 6.1, 95 CI 1.9–19.9, P = 0.002) were significantly associated with OS.ConclusionsOur results showed that high ERCC1 expression was independently associated with shorter disease-free and overall survival in patients with bladder cancer who received neoadjuvant platinum-based chemotherapy. ERCC1 may represent a potential predictive marker for platinum-based treatment in bladder cancer. 相似文献
89.
90.
目的研究生脉注射液治疗急性心肌梗死后心源性休克的临床疗效。方法选取2015年6月—2016年8月十堰市太和医院治疗的急性心肌梗死后心源性休克患者164例,随机分为对照组和治疗组,每组各82例,对照组给予常规治疗,治疗组在对照组的基础上静脉滴注生脉注射液,60 m L加入5%葡萄糖溶液250~500 m L,1次/d。两组均连续治疗7 d。治疗后,观察两组患者临床疗效,同时比较血清心肌肌钙蛋白I(c Tn I)、钙调蛋白(Ca M)及其基因表达,心功能指标左心室内压最大上升速率(dp/dtmax)、左心室内压最大下降速率(-dp/dtmax)、左室射血分数(LVEF)、舒张末期室间隔厚度(IVST)、左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、心脏指数(CI),及肺毛细血管楔压(PCWP)、心率(HR)、收缩压(SBP)、舒张压(DBP)、脉压(PP)和尿量(UV)的变化。结果治疗后,对照组和治疗组总有效率分别为60.97%和74.39%,两组总有效率比较差异有统计学意义(P0.05)。两组c Tn I、Ca M、c Tn I-m RNA和Ca MKII-m RNA均较治疗前显著降低,同组治疗前后差异有统计学意义(P0.05),且治疗组上述指标降低更明显,两组比较差异有统计学意义(P0.05)。两组±dp/dtmax、LVEF和CI均升高、LVEDD增大,IVST和LVESD均缩小(P0.05),且治疗组上述指标改善更明显(P0.05)。两组患者PCWP和HR均降低,SBP和DBP均升高,PP增大,UV增多(P0.05),且治疗组上述指标改善更明显(P0.05)。治疗组并发症中室间隔穿孔、急性肾衰竭和心律失常和死亡率明显低于对照组,两组比较差异具有统计学意义(P0.05)。结论生脉注射液治疗急性心肌梗死后心源性休克疗效显著,纠正急性心肌梗死时心肌"钙超载"现象,明显增强心脏泵血功能,具有一定的临床推广应用价值。 相似文献