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71.
Shinsuke Kikuchi Lihua Chen Kevin Xiong Yukihiro Saito Nobuyoshi Azuma Gale Tang Michael Sobel Thomas N. Wight Richard D. Kenagy 《Journal of vascular surgery》2018,67(5):1556-1570.e9
Objective
Venous valves are essential but are prone to injury, thrombosis, and fibrosis. We compared the behavior and gene expression of smooth muscle cells (SMCs) in the valve sinus vs nonvalve sites to elucidate biologic differences associated with vein valves.Methods
Tissue explants of fresh human saphenous veins were prepared, and the migration of SMCs from explants of valve sinus vs nonvalve sinus areas was measured. Proliferation and death of SMCs were determined by staining for Ki67 and terminal deoxynucleotidyl transferase dUTP nick end labeling. Proliferation and migration of passaged valve vs nonvalve SMCs were determined by cell counts and using microchemotaxis chambers. Global gene expression in valve vs nonvalve intima-media was determined by RNA sequencing.Results
Valve SMCs demonstrated greater proliferation in tissue explants compared with nonvalve SMCs (19.3% ± 5.4% vs 6.8% ± 2.0% Ki67-positive nuclei at 4 days, respectively; mean ± standard error of the mean, five veins; P < .05). This was also true for migration (18.2 ± 2.7 vs 7.5 ± 3.0 migrated SMCs/explant at 6 days, respectively; 24 veins, 15 explants/vein; P < .0001). Cell death was not different (39.6% ± 16.1% vs 41.5% ± 16.0% terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, respectively, at 4 days, five veins). Cultured valve SMCs also proliferated faster than nonvalve SMCs in response to platelet-derived growth factor subunit BB (2.9 ± 0.2-fold vs 2.1 ± 0.2-fold of control, respectively; P < .001; n = 5 pairs of cells). This was also true for migration (6.5 ± 1.2-fold vs 4.4 ± 0.8-fold of control, respectively; P < .001; n = 7 pairs of cells). Blockade of fibroblast growth factor 2 (FGF2) inhibited the increased responses of valve SMCs but had no effect on nonvalve SMCs. Exogenous FGF2 increased migration of valve but not of nonvalve SMCs. Unlike in the isolated, cultured cells, blockade of FGF2 in the tissue explants did not block migration of valve or nonvalve SMCs from the explants. Thirty-seven genes were differentially expressed by valve compared with nonvalve intimal-medial tissue (11 veins). Peptide-mediated inhibition of SEMA3A, one of the differentially expressed genes, increased the number of migrated SMCs of valve but not of nonvalve explants.Conclusions
Valve compared with nonvalve SMCs have greater rates of migration and proliferation, which may in part explain the propensity for pathologic lesion formation in valves. Whereas FGF2 mediates these effects in cultured SMCs, the mediators of these stimulatory effects in the valve wall tissue remain unclear but may be among the differentially expressed genes discovered in this study. One of these genes, SEMA3A, mediates a valve-specific inhibitory effect on the injury response of valve SMCs. 相似文献72.
73.
脊索瘤是临床少见的原发性低度恶性骨肿瘤,源自残留的胚胎脊索或迷走的脊索组织,好发于中轴骨,具有局部侵袭性、复发率高、预后差,以及对放射治疗和药物化疗不敏感等特点,使其临床治疗存在巨大挑战。位于活动节段的脊柱脊索瘤由于脊柱特有的解剖学特点而具有其独特特点,本文通过回顾近年国内外相关文献,对脊索瘤生物学行为特点进行概述,以期为脊索瘤治疗提供新的思路。 相似文献
74.
75.
K B Raja G P Smith T J Peters 《Clinica chimica acta; international journal of clinical chemistry》1981,117(1):33-41
A new rapid assay for inorganic pyrophosphatase has been developed and the procedure optimised for measurement of the enzyme in human neutrophils. Kinetic studies showed that the activity was optimal at pH 8.0 and was activated by Mg2+. No neutral or acid pyrophosphatase was detected. Neutrophils were homogenised in isotonic sucrose and, after low speed centrifugation the intracellular localization of pyrophosphatase was determined by analytical subcellular fractionation with sucrose density gradient centrifugation. Pyrophosphatase was shown to have a dual localization to mitochondria and cytosol. No activity could be attributed to either the endoplasmic reticulum or alkaline phosphatase-containing granules (phosphasomes). Inhibitor studies clearly show that the cytosolic and mitochondrial pyrophosphatases are due to distinct enzymes. Neutrophils were isolated from control subjects, patients with chronic granulocytic leukaemia and subjects in the third trimester of pregnancy. The specific activity (mU/mg protein) of pyrophosphatase, in contrast to that of alkaline phosphatase was similar in the three groups. Levamisole, a potent inhibitor of alkaline phosphatase had no effect on pyrophosphatase activity, confirming that this activity is not attributable to neutrophil alkaline phosphatase. 相似文献
76.
77.
为了有效、准确地检测霍乱弧菌,在某地水样泻患者的粪便中分离4株O139霍乱弧菌,经对分离株的生物学特性、血清学及药物敏感性进行研究,并与O1群霍乱弧菌进行比较。结果表明,O139霍乱弧菌具有O1群同样的生化特性,但不与O1群霍乱弧菌抗血清凝集,仅与O139霍乱弧菌抗血清在玻片上呈强凝集,试管凝集滴度为1:640~1:2560,所有菌株都使鸡红细胞凝集,对羊红细胞溶血的作用可变。所有菌株对霍乱O1群特异的mukherjee's噬菌体有抗性,对O/129多粘菌素B等药物耐药;而对红霉素、环丙氟哌酸等抗生素敏感。O139与O1群霍乱弧菌的不同特征,可作为鉴别的参考依据,但由于观察的菌株尚少,有待进一步研究。 相似文献
78.
丙型肝炎病毒核心蛋白反式激活基因HCTP4启动子序列的确定及转录活性的鉴定 总被引:1,自引:0,他引:1
目的:研究丙型肝炎病毒(HCV)核心蛋白(core)反式激活基因HCTP4基因序列表达的调控机制。方法:选取翻译起始密码子ATG上游44l bp的DNA序列为启动子序列,应用聚合酶链反应技术(PCR),以肝母细胞瘤细胞系HepG2基因组DNA为模板,扩增该启动子DNA片段,将其克隆至pCAT3中,构建pCAT3-HCTP4-promoter报告基因表达载体,以该质粒转染HepG2细胞,用酶联免疫吸附方法(ELISA)检测报告基因编码产物氯霉素乙酰转移酶(CAT)的表达活性。结果:发现质粒pCAT3-HCTP4-promoter能够指导CAT的表达,吸光度(A值)是pCAT3对照质粒的5倍。结论:本研究克隆的启动子DNA序列具有转录活性,这一结果为研究HCTP4的调节机制,进一步阐明丙型肝炎病毒核心蛋白的作用机制奠定了基础。 相似文献
79.
小肠恶性肿瘤病因学研究进展 总被引:1,自引:0,他引:1
小肠恶性肿瘤较罕见,近年随着胶囊内镜、双气囊小肠镜的应用,其发病率呈不断上升的趋势。饮食和生活习惯、肥胖和身高、职业、癌前疾病等多种危险因素在小肠恶性肿瘤的发生中起重要作用。此外,分子遗传学亦对其发生发挥了一定的作用。本文就此作一综述。 相似文献
80.
目的本研究旨在通过检测中国西北人群白血病患者和健康对照组中CD38基因184位点的基因型分布特点,探讨CD38基因多态性与中国西北人群白血病易感的相关性,揭示白血病患者CD38基因多态性与白血病不同生物学特征的相关性以及对其预后的影响。方法采用病例对照设计,包含100例患者,100例正常对照,采用聚舍酶链反应一限制性片段长度多态性技术(PCR-RFLP)检测cD38基因184住点的多态性,应用x2检验和精确概率法比较各基因型频率在病例组与对照组之间的差异。结果白血病组与对照组相比,GG、GC、CC基因型频率无统计学差异(P=0.072)。初诊时WBC〉50×109/L、Hb〈100g/L、LDH〉450、脾脏肿大、伴有Ph染色体异常的患者与对照组GG、GC、CC基因型比较差异有统计学意义(P〈O.05)。结论CD38基因184位点多态性可能与白血病的发病风险无关,GG、GC变异基因型可能与白血病患者主要生物学特征有关。 相似文献