共表达分子伴侣蛋白提高III型普鲁兰水解酶在短小芽孢杆菌中的分泌表达及发酵优化

本研究旨在通过共表达分子伴侣蛋白以及优化发酵条件来提高III型普鲁兰水解酶(TK-PUL)在短小芽孢杆菌中的分泌表达水平。通过构建共表达TK-PUL和分子伴侣蛋白的多种重组短小芽孢杆菌,并以胞外酶活为指标对其进行筛选,确定最有利于TK-PUL分泌表达的分子伴侣蛋白及对应的重组短小芽孢杆菌。在此基础上采用单因素实验和响应面法优化重组短小芽孢杆菌的发酵条件。结果表明,共表达分子伴侣蛋白PrsA^(Ba)的重组短小芽孢杆菌的胞外酶活达到98.79 U/mL,提高了0.31倍。该重组短小芽孢杆菌的最佳培养基包括19.65 g/L葡萄糖、21.46 g/L酵母提取物、12.01 g/L MgCl_(2)·6H_(2)O、9.02 g/L脯氨酸、0.01 g/L FeSO4·7H_(2)O、0.01 g/L MnSO4·4H_(2)O、0.001 g/L ZnSO4·7H_(2)O。在发酵温度为35℃、起始发酵pH为7.0的条件下,该重组短小芽孢杆菌于最佳培养基中培养66 h时,其胞外酶活达到192.68 U/mL,提高了1.56倍。本研究通过共表达分子伴侣蛋白和发酵优化实现了TK-PUL在短小芽孢杆菌的高效分泌表达,为TK-PUL的应用提供了基础。

混合牙列期骨性III类错合与骨性I类错合基骨及牙弓对比研究

目的:通过测量混合牙列期骨性III类错合患者与骨性I类错合患者的锥形束计算机断层扫描(Cone beam computed tomography, CBCT),对比分析上下颌牙弓、基骨弓长度与宽度差异及协调性,以期为替牙期骨性III类错合畸形治疗提供参考依据。方法:选择替牙列期骨性III类错合与骨性I类错合各30例,通过Dolphin软件处理收集到的DICOM (Digital Imaging and Communications in Medicine)医学图像数据,行三维重建并测量上下颌牙弓、基骨弓的长度与宽度,计算同一牙段牙弓宽度与基骨弓宽度之间的差值,比较骨性III类与骨性I类错牙合畸形牙弓与基骨弓宽度差值的差异。结果:1) 骨性III类错合组上颌牙弓及基骨弓长度均小于骨性I类错合组,下颌基骨弓长度大于骨性I类错合组,且差异有统计学意义(P 0.05)。2) 骨性III类错合组下颌前段及中段基骨弓宽度大于骨性I类错合组,差异有统计学意义(P 0.05)。3) 骨性III类错合组上颌牙弓与基骨弓宽度的差值均大于骨性I类错合组,下颌牙弓与基骨弓宽度的差值均小于骨性I类错合组,其中上颌后段牙弓宽度与基骨弓宽度差值差异有统计学意义(P < 0.05)。结论:混合牙列期骨性III类错合存在牙弓、基骨弓不调,上颌可扩大基骨弓,下颌可扩大牙弓,以期改善牙弓与基骨弓的协调性。

基于NSGA-III算法求解柔性作业车间调度问题

针对多目标柔性作业车间调度问题,提出一种改进NSGA-Ⅲ算法,以完工时间、机器总负荷、瓶颈机器负荷为目标建立调度模型。首先,为提高种群的多样性,提出一种基于惩罚的边界相交距离定义关联操作中种群个体与参考向量之间的距离;其次,为提高环境选择的计算效率,利用基于惩罚的边界相交距离消除机制来保护个体,降低了个体保护策略的计算成本;最后,为避免种群陷入局部最优,在遗传算子中采用一种改进的变异策略。运用两个评价指标与NSGA-Ⅲ算法进行比较,其收敛性与多样性均由于NSGA-Ⅲ算法。同时在4个Kacem算例上进行测试得出改进NSGA-Ⅲ算法解的质量较高,最后通过实际的生产实例证明改进的NSGA-Ⅲ算法优于或等同于现存在的方法,也证明了该方法在解决多目标柔性作业车间调度难题上的可操作性。

Unlocking the potential of ultra-thin two-dimensional antimony materials:Selective growth and carbon coating for efficient potassium-ion storage

Antimony-based anodes have attracted wide attention in potassium-ion batteries due to their high theoretical specific capacities(∼660 mA h g^(-1))and suitable voltage platforms.However,severe capacity fading caused by huge volume change and limited ion transportation hinders their practical applications.Recently,strategies for controlling the morphologies of Sb-based materials to improve the electrochemical performances have been proposed.Among these,the two-dimensional Sb(2D-Sb)materials present excellent properties due to shorted ion immigration paths and enhanced ion diffusion.Nevertheless,the synthetic methods are usually tedious,and even the mechanism of these strategies remains elusive,especially how to obtain large-scale 2D-Sb materials.Herein,a novel strategy to synthesize 2D-Sb material using a straightforward solvothermal method without the requirement of a complex nanostructure design is provided.This method leverages the selective adsorption of aldehyde groups in furfural to induce crystal growth,while concurrently reducing and coating a nitrogen-doped carbon layer.Compared to the reported methods,it is simpler,more efficient,and conducive to the production of composite nanosheets with uniform thickness(3–4 nm).The 2D-Sb@NC nanosheet anode delivers an extremely high capacity of 504.5 mA h g^(-1) at current densities of 100 mA g^(-1) and remains stable for more than 200 cycles.Through characterizations and molecular dynamic simulations,how potassium storage kinetics between 2D Sb-based materials and bulk Sb-based materials are explored,and detailed explanations are provided.These findings offer novel insights into the development of durable 2D alloy-based anodes for next-generation potassium-ion batteries.

Soil Profile Concentration Distributions of Antimony and Bismuth across Southeastern Missouri (USA)

Recent research has suggested that increased industrial and technological utilization of antimony and bismuth necessitates greater research to determine the soil and water chemistry and the environmental risks associated with these elements. The near-total soil profile concentrations of antimony and bismuth were determined for key soil series across southeastern Missouri. The antimony concentrations ranged from 0.65 to 0.08 mg kg−1, whereas the bismuth soil profile concentrations ranged from 0.92 to 0.03 mg kg−1. Most pedons showed antimony concentrations ranging from 20 to 30 mg kg−1, whereas bismuth concentrations were commonly 10 to 20 mg kg−1. For soils having argillic horizons, antimony and bismuth concentrations were greater for the illuvial horizons than the eluvial horizons, whereas Entisols, Inceptisols, and one Vertisol showed rather uniform antimony and bismuth concentrations, features paralleling the soil texture distribution. Both antimony and bismuth showed significant correlations with iron.

Trace element compositions of pyrite and stibnite:implications for the genesis of antimony mineralization in the Yangla Cu skarn deposit,Northwestern Yunnan,China

The Yangla Cu skarn deposit is located in the central part of the Jinshajiang Suture Zone,southwest China,with a total reserve of 150 Mt Cu@1.03%.The newly discovered antimony orebodies at the depth of Yangla are strictly controlled by the stratum,structure,and lithology,which are lenticular and vein-like within the marble fracture zone,which can provide a window into multistage miner-alization and ore genesis at Yangla.Mineralization can be divided into three types,Cu–Pb–Zn(skarn)pyrite,galena,and sphalerite,Cu(porphyry)chalcopyrite and pyrite,and Sb(hydrothermal)stibnite and pyrite.The mineral assem-blages were stibnite+pyrite+calcite+quartz±minor scheelite in antimony ores.This study presents quantitative measurements of the trace element compositions of pyrite and stibnite from the Yangla antimony ores.Analysis of pyrite with electron probe microanalysis(EPMA)showed enrichment in Co,Ni,Sb,As,and Mo,and deficit in its S and Fe contents when compared to the stoichiometric con-centrations of S and Fe in pyrite.The Sb-related pyrite may belong to sedimentary-reworked genesis and may be modi-fied by hydrothermalfluids,thereby presenting a certain dif-ference(i.e.,crystal morphology,texture,and chemical com-position)compared to the skarn and porphyry Cu-related pyrite in the Yangla Cu skarn deposit.Analysis of stibnite with EPMA and inductively coupled plasma-mass spectrom-etry showed enrichment in As,Pb,Sn,Pb,Cu,and Zn,and presented much higher Sb contents and slightly lower S con-tents when compared to the stoichiometric concentrations of Sb and S in stibnite.Statistical analysis of the stibnite trace elements showed correlations for the elemental pairs Cu–Pb,As–Sb,and Sn–Pb,and the coupled substitution equations Sb^(3+)↔Cu^(+)+Pb^(2+),Sb^(3+)↔As^(3+),and Sn^(2+)↔Pb^(2+)may be the major factors governed the incorporating Cu,Pb,As and Sn within the stibnite.Moreover,this study preliminary shows that the antimony mineralization may belong to a car-bonate replacement hydrothermal genesis at Yangla.

III型胶原蛋白在乳腺癌中的研究进展

乳腺癌(Breast cancer, BC)于2020年在全球新增癌症病例成为了最常见癌症,且发病率逐年升高。胶原蛋白是构成细胞外基质(Extracellular Matrix, ECM)的主要成分,近年来的研究发现III型胶原蛋白(Collagen Type III, COLIII)在乳腺癌的发生、发展过程中发挥重要作用,并对肿瘤微环境(Tumor micro-environment, TME)的维持有重要意义。其中,癌症相关成纤维细胞(Cancer-associated fibroblasts, CAFs)在建立和重塑ECM结构中扮演关键角色,调控肿瘤细胞通过TME入侵的进程。但由于该体系庞大,通过分泌细胞因子和趋化因子与癌细胞相互作用的机制复杂,各成分及其亚型在癌症进展中的角色尚存争议。本文基于TME在乳腺恶性肿瘤中的研究现状以及作为ECM中重要成分的COLIII的性质结构、形态分布,分析COLIII通过改变ECM的机械力与刚度影响乳腺癌行为的机制,同时充分讨论特殊结构、来源的COLIII在微环境中的不同功能及作用方式,评估其应用于癌症治疗的可能性。

Target-induced Trivalent G-quadruplex/hemin DNAzyme for Colorimetric Detection of Hg^(2+) Based on an Exonuclease III Assisted Catalytic Hairpin Assembly

Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly formation of a trivalent G-quadruplex/hemin DNAzyme for colorimetric detection of Hg^(2+).A hairpin DNA(Hr)was designed with thymine-Hg^(2+)-thymine pairs that catalyzed by Exo III is prompted to happen upon binding Hg^(2+).A released DNA fragment triggers the catalytic assembly of other three hairpins(H1,H2,and H3)to form many trivalent G-quadruplex/hemin DNA enzymes for signal output.The developed sensor shows a dynamic range from 2 pM to 2μM,with an impressively low detection limit of 0.32 pM for Hg^(2+)detection.Such a sensor also has good selectivity toward Hg^(2+)detection in the presence of other common metal ions.This strategy shows the great potential for visual detection with portable type.

中青年视网膜静脉阻塞与同型半胱氨酸、抗凝血酶III相关研究

目的:研究分析中青年视网膜静脉阻塞(Retinal Vein Occlusion, RVO)患者同型半胱氨酸(Homocysteine, Hcy)及抗凝血酶III (Antithrombin III, AT-III)水平,两者是否作为致病危险因素参与RVO发病。分析视网膜中央静脉阻塞(CRVO)和视网膜分支静脉阻塞(BRVO)危险因素的差异,为治疗和预防该病提供客观依据。方法:1) 所有研究对象选自2021年10月至2023年12月期间就诊于内蒙古自治区人民医院眼科的年龄 P > 0.05)。三组患者之间在Hcy、AT-III、胆固醇(CHOL)、叶酸、维生素B12、D-二聚体(D-D)、纤维蛋白降解产物(FDP)水平差异均有统计学意义(P P P < 0.001)。结论:1) Hcy水平升高和AT-III活性缺乏为中青年CRVO和BRVO的危险因素。2) 相对于BRVO患者,CRVO组中Hcy水平升高和AT-III缺乏的值更为显著。

种植体支抗对快速扩弓后III类错颌患者上合骨A点的即刻变化影响研究

探讨种植体支抗对快速扩弓后III类错颌患者上合骨A点的即刻变化影响。方法 将受试者随机分为种植体支抗组和横腭杆组。对比分析不同组别治疗前后各项测量值的变化量以及所需治疗时间。结果 种植体支抗组的U1-Y, U6-Y, UL-EP, U1-SN各指标变化量与横腭杆组相比,差异具有统计学意义;反之,SNA, SNB, ANB各指标差异无统计学意义。在治疗时间上,种植体支抗组的结果与横腭杆组接近,差异不显著。结论 种植体支抗带来的即刻变化影响显著,有效改善了III类错颌患者的上合骨A点情况,而总体的治疗时间对比横腭杆组并无显著增加。这些建议种植体支抗应为快速扩弓后III类错颌患者的有效治疗手段。

锑氧化菌Pseudomonas sp.AO-1的分离鉴定及其对Sb(III)的氧化性能

采用抗性筛选法从锡矿山筛选出一株锑氧化菌,并利用分子生物学技术对其进行鉴定;考察了其氧化Sb()Ⅲ的性能和氧化次生矿物的特征.结果表明:锑氧化菌属于假单胞菌属(Pseudomonas),将其命名为Pseudomonas sp.AO-1(简称:AO-1);影响AO-1氧化Sb(Ⅲ)的因素主要有溶液pH值、溶解氧和铁锰氧化物(单质铁、FeCl_(3)和MnO_(2))等;AO-1在好氧和缺氧条件下均能氧化Sb(Ⅲ),好氧氧化Sb(Ⅲ)的米门常数Km和最大氧化速率Vmax值分别为393.05µmol/L和0.271µmol/(L·min),体现了较强的锑氧化性;AO-1和铁锰氧化物的耦合作用能促进Sb(Ⅲ)的氧化,且铁锰氧化物促进AO-1氧化Sb(Ⅲ)的速率依次为:FeCl_(3)>MnO_(2)>单质铁;AO-1和铁锰氧化物耦合氧化Sb(Ⅲ)生成含Sb(Ⅴ)的次生矿物,次生矿物会加速Sb(Ⅲ)的氧化以及影响锑在环境中的迁移转化.菌株AO-1的锑氧化性能良好,对于锑的生物化学转化和土壤微生物修复的应用有重要意义.

Adsorptive Removal of Antimony (III) Using Modified Montmorillonite: A Study on Sorption Kinetics

The adsorptive removal of antimony (III) has been successfully obtained on montmorillonite (MMT) and modified MMT from synthetic solution. The adsorption behavior of the modified and unmodified MMT has been investigated as a function of initial concentration of metal ion in the solution, pH of the solution and contact time using a batch extraction process. The optimized process can be applied for the adsorption, detection and estimation of antimony from 0.006 μg/ml (6.0 ppb) to 100.00 μg/ml (100.0 ppm) in aqueous solution. It has been observed that almost 99% of antimony (III) can be successfully extracted from a solution containing 100 μg/ml of the metal ion at pH 6.0 at 25?C ± 2?C. The investigation of the kinetics of sorption of antimony (III) on MMT/modified MMTshows intraparticle diffusion to be the rate limiting step during the initial stages of adsorption followed by chemisorption.

Sublethal Antimony (III) Exposure of Freshwater Swamp Shrimp (Macrobrachium Nipponense): Effects on Oxygen Consumption and Hepatopancreatic Histology

This study was an attempt to realize the effects of antimony on freshwater swamp shrimp (Macrobrachium nipponense). An experiment of this nature, which have not previously been carried out in this species. First, median lethal concentrations were determined in acute toxicity tests. The 96-h LC50 value was 6.748 (5.728-7.950) mg Sb/l for adult M. nipponense and 1.635 (1.271-2.103) mg Sb/l for juvenile M. nipponense. Juvenile M. nipponense were exposed to 4 different sublethal levels of antimony (0.1, 0.4, 0.8, and 1.2 mg Sb/l) over a 7-d test period and a 7-d recovery period. After 30 min (acute), there was an increase in the amount of oxygen consumed in all exposed groups. On days 3, 7, and 14, decreases in oxygen consumption were significant (p < 0.05) for the higher-exposure level groups (0.8 and 1.2 mg/l). Light microscopy investigations showed histopathological alterations in the hepatopancreas which correlated with exposure concentrations. The alterations included degenerative changes in the lumen, a reduction in the lumen volume, and injury to epithelial cells in the histoarchitecture of hepatopancreas.

重组III型人源化胶原蛋白修护贴敷料联合光子嫩肤对不适症状以及肤质改善的研究

评价重组III型人源化胶原蛋白修护贴敷料在光子嫩肤术后缓解不适症状以及对肤质改善的作用。方法 选择2022年7月—2023年2月于本医院门诊接受光子嫩肤治疗的120例患者,根据1:1简单随机分配原则把患者分为联合组与对照组各60例采用光子嫩肤治疗。联合组给予重组III型人源化胶原蛋白修护贴敷料联合光子嫩肤治疗,对照组用保湿贴敷料代替重组III型人源化胶原蛋白修护贴敷料,同样联合光子嫩肤治疗,两组都治疗观察4周。结果 1、联合组和对照组在术后第2、6、10天的不适症状评分均呈逐渐下降趋势,其中联合组改善程度更为明显。对光子术后即刻与术后第8天评分差值对比,联合组相较对照组具有统计学差异。2、首次进行光子术前,第二次光子术前,第三次光子术前,第12周结束对肤质情况信息录取。联合组和对照组,肤质均有所改善。第12周较光子术前改善对比,联合组改善更为明显,且P<0.05,差异有统计学意义。结论 1、重组III型人源化胶原蛋白修护贴敷料可明显缓解光子术后面部皮肤产生的不适症状,有良好的辅助治疗作用。2、重组III型人源化胶原蛋白修护贴敷料联合光子嫩肤能更好的改善肤质,起到肤质改善的作用。

DFR、抗凝血酶III概况及其在急性肺栓塞中的应用

急性肺栓塞是多种因素共同作用下发生的、可严重危及生命的一种疾病。因其临床表现、体征缺乏特异性,单一检测往往不足以满足诊断需要,误诊率及漏诊率大,病死率高。故在疾病初期采取何种有效的方式进行诊断已成为临床研究热题。D-二聚体为反映纤溶亢进的指标,纤维蛋白原为凝血的指标,DFR作为D-D与Fbg的比值,在一定程度上可以反映纤溶与凝血之间的平衡。抗凝血酶III具有显著的抗凝血作用,其水平下降影响机体抗凝作用,促进血栓形成。

Gartland III型伸直型儿童肱骨髁上骨折的治疗进展

Gartland III型伸直型儿童肱骨髁上骨折是临床上一种较为严重肘部骨折,常合并神经血管损伤,如果治疗不当,会导致严重的并发症,对患儿的身心健康造成不利的影响。由于其骨折端之间骨皮质完全断裂,有明显的侧方和(或)旋转移位,相对不稳定,所以闭合复位相对难度较大。本文将通过查阅近年来关于Gartland III型伸直型儿童肱骨髁上骨折治疗研究进展的相关文献作一综述,旨在加深对该型骨折临床特征的认识并系统阐述其诊治方式的发展现状,为临床决策提供科学依据。

Growth and Antimony Bioconcentration Characteristics of Wild Ramie(Boehmeria nivea)under Sb Stress in Different Valence States

[Objectives] To explore the effects of antimony(Sb) in different valence states on the growth and Sb bioconcentration and transfer of wild ramie(Boehmeria nivea). [Methods] A pot experiment was conducted to study the effects of Sb(Ⅲ) and Sb(Ⅴ) stress on plant height, biomass, leaf SPAD value, Sb contents in various organs, Sb bioconcentration and transfer factors, and other indexes. [Results] Both kinds of Sb treatments showed a trend of "first increasing and then decreasing" in plant height as Sb concentration increased. The plant heights in Sb(Ⅲ) treatments with a concentration lower than 1 000 mg/kg and Sb(Ⅴ) treatments with concentrations lower than 4 000 mg/kg were significantly higher than that of the control check(CK);and the Sb(Ⅲ) treatment of the high concentration(4 000 mg/kg) resulted in a significant decrease in plant height, while the 8 000 mg/kg Sb(Ⅴ) treatment still showed an increase in plant height, indicating that the toxicity of Sb(Ⅴ) to wild ramie was significantly lower than that of Sb(Ⅲ). The Sb(Ⅲ) treatments with a concentration lower than 2 000 mg/kg had little effect on the dry weight of the aboveground part, while the treatment with a higher concentration showed a significant decrease;and the dry weights in various concentrations of Sb(Ⅴ) treatments showed no significant differences, but they were significantly higher than the CK and corresponding concentration of Sb(Ⅲ) treatment. Both types of Sb stress could promote the increase of SPAD value in wild ramie leaves, and the performance was significantly higher than the CK. As the concentration of Sb treatment increased, the Sb content in both the aboveground and underground parts showed a significant increase;and the comparison of Sb content under corresponding concentrations of the two types of Sb treatments showed that in the aboveground part, Sb(Ⅲ) was higher than Sb(Ⅴ), while in the underground part, the opposite was true. The bioconcentration factor(BF) of Sb decreased with the increase of Sb treatment concentration overall, and the value of Sb(Ⅴ) was smaller than that of Sb(Ⅲ), but both kinds of Sb stress were significantly smaller than the CK. The transfer factor(TF) of Sb in wild ramie showed a trend of "increasing first and then decreasing" with the concentration of Sb treatment, and various treatments of Sb(Ⅲ) were higher than the CK, with significant differences, while among various treatments of Sb(Ⅴ), except treatment B3, the reduction of which was not significant, other Sb(Ⅴ) treatments showed significant decreases. Comparing the two types of Sb treatments, the BF and TF values of Sb in wild ramie under Sb(Ⅲ) treatments were higher than those under Sb(Ⅴ) treatments, and the TF reached a significant level, indicating that the Sb transport ability of wild ramie under Sb(Ⅲ) treatments was stronger. [Conclusions] This study provides a theoretical basis for the mining of wild ramie Sb restoration genes and the application of large-scale cultivation in ecological restoration.

Unraveling the influence of interface defects on antimony trisulfide solar cells

Antimony trisulfide(Sb_(2)S_(3)) solar cells suffer from large open circuit voltage deficits due to their intrinsic defects which limit the power conversion efficiency.Thus,it is important to elucidate these defects’ origin and defects at the interface.Here,we discover that sulfide radical defects have a significant impact on the performance of Sb_(2)S_(3)solar cells.Moreover,it has been illustrated that these defects at the CdS/Sb_(2)S_(3)interface can be reduced by optimizing the deposition process.A trap distribution model is used to quantify the defect density at the CdS/Sb_(2)S_(3)interface.It shows that the interface defects can be reduced by24% by improving the deposition process.This work reveals the importance of interface defects and guides the future optimization of Sb_(2)S_(3)solar cells.

Effects of Antimony Stress on Root Growth,Antimony Accumulation and Physiological Characteristics of Ramie(Boehmeria nivea(L.) Gaudich.)

[Objectives]This study was conducted to investigate the toxicity of heavy metal antimony(Sb) to ramie(Boehmeria nivea(L.) Gaudich.) and the tolerance response in ramie. [Methods] A pot experiment was conducted to study the effects of Sb stress on root growth and Sb accumulation and transport of the root system of cultivated ramie Zhongzhu No.1, as well as on the physiological characteristics of ramie leaves. [Results] The plant height and root dry weight and volume of Zhongzhu No.1 showed an effect of "promoting at low concentrations and inhibiting at high concentrations" with the increase of Sb concentration, and decreased significantly at the concentration of 4 000 mg/kg, but no obvious toxic growth symptoms were observed. The content of Sb in roots(289.7-508.6 mg/kg) and the root-shoot transfer factor(0.09-0.57) of Zhongzhu No.1 increased with the increase of soil Sb concentration, but the change of Sb bioconcentration factor in roots was opposite, indicating that high concentrations of Sb in soil could promote the absorption of Sb in roots and the transport of Sb to the aboveground part, but the Sb enrichment capacity of roots was relatively reduced with the increase of soil Sb. Sb stress had a certain impact on the physiological characteristics of ramie leaves. With the increase of Sb treatment concentration, MDA, POD and SOD showed a change trend of "first increasing and then decreasing", while CAT gradually increased, indicating that Sb stress caused changes in the physiological characteristics of ramie leaves, thereby affecting plant growth and development. [Conclusions] This study provides a theoretical basis for ecological restoration of ramie in mining areas.

Size matters:analyzing bank profitability and efficiency under the Basel III framework

The latest regulatory framework,which has been introduced globally in the form of Basel III,and its implementation in the legislation of the member states of the Euro-pean Union has generated much interest in the impact of regulation on the efficiency and profitability of banks.This study aims to examine the impact of the introduction of two major regulatory changes(Basel II and Basel III)on bank performance,in terms of bank size and bank-specific and macroeconomic variables.A two-stage empirical anal-ysis was conducted on a sample of 433 European commercial banks over the 2006–2015 period.In the first stage,relative efficiency was calculated using non-parametric data envelopment analysis.In the second stage,the generalized method of moments was used to examine the impact of bank-specific and macroeconomic variables as well as regulation on bank performance,that is,profitability and efficiency.Consider-ing bank size,the results show a diverse impact of regulation on bank performance.Regarding large-and medium-sized banks,regulation positively affects both efficiency and profitability,whereas,for small banks,it negatively affects performance.The results suggest that larger banks have skillfully adapted to the new regulatory environment.In contrast,small banks have problems with profitability and efficiency because the new regulatory framework has imposed additional administrative and regulatory burdens.This could result in future failure or mergers with larger banks,resulting in a higher concentration in the banking sector and increased systemic risk.Our results strongly suggest that regulation should not be implemented equally for all banks;that is,on a one size fits all terms.A distinction between small and large banks when introducing new regulatory frameworks should be made if a reasonable level of competition is to be preserved.