Effect of addition of chitosan to self-etching primer:antibacterial activity and push-out bond strength to radicular dentin

The purpose of this study was to evaluate the antibacterial activity of a modified self-etching primer incorporating chitosan and whether this modification affected the bond strength to radicular dentin.A modified self-etching primer was prepared by adding chitosan solutions at 0.03%,0.06%,0.12% and 0.25%（W/W） to RealSeal selfetching primer.RealSeal primer without chitosan was used as the control.The antibacterial activity of the modified self-etching primer was evaluated using the direct contact test against Enterococcus faecalis.The bonding ability of the RealSeal system to radicular dentin was evaluated using the push-out bond strength test.The modes of failure were examined under a stereomicroscope.Data were analyzed using analysis of variance（ANOVA） and Tukey’s test,with a P-value 〈 0.05 indicating statistical significance.The results showed that the antibacterial properties of the freshly prepared and aged modified self-etching primer incorporating chitosan exhibited potent antibacterial effect against Enterococcus faecalis compared with the unmodified primer.The RealSeal system with the aged modified self-etching primer incorporating chitosan showed no significant differences in the bond strength as compared with the control（P = 0.99）.The findings suggest that modified self-etching primer incorporating chitosan is a promising antibacterial primer which does not adversely affect the bond strength of the RealSeal system to radicular dentin.

An in-situ self-etching enabled high-power electrode for aqueous zinc-ion batteries

Sluggish storage kinetics is considered as the main bottleneck of cathode materials for fast-charging aqueous zinc-ion batteries(AZIBs).In this report,we propose a novel in-situ self-etching strategy to unlock the Palm tree-like vanadium oxide/carbon nanofiber membrane(P-VO/C)as a robust freestanding electrode.Comprehensive investigations including the finite element simulation,in-situ X-ray diffraction,and in-situ electrochemical impedance spectroscopy disclosed it an electrochemically induced phase transformation mechanism from VO to layered Zn_(x)V_(2)O_5·nH_(2)O,as well as superior storage kinetics with ultrahigh pseudocapacitive contribution.As demonstrated,such electrode can remain a specific capacity of 285 mA h g^(-1)after 100 cycles at 1 A g^(-1),144.4 mA h g^(-1)after 1500 cycles at 30 A g^(-1),and even 97 mA h g^(-1)after 3000 cycles at 60 A g^(-1),respectively.Unexpectedly,an impressive power density of 78.9 kW kg^(-1)at the super-high current density of 100 A g^(-1)also can be achieved.Such design concept of in-situ self-etching free-standing electrode can provide a brand-new insight into extending the pseudocapacitive storage limit,so as to promote the development of high-power energy storage devices including but not limited to AZIBs.

Effect of Multiple Coatings of One-step Self-etching Adhesive on Microtensile Bond Strength to Primary Dentin

Objective To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin.Methods Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each.In group 1,each tooth was hemisected into two halves.One half was assigned to control subgroup 1,which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing.In group 2,the teeth were also hemisected into two halves.One half was assigned to control subgroup 2,which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer.Microtensile bond strength was immediately tested after specimen preparation.Results When the adhesive was applied three times before light curing,the bond strength of the experimental subgroup 1(n=33,57.49±11.61 MPa) was higher than that of the control subgroup 1(n=31,49.71±11.43 MPa,P<0.05).When using the technique of applying multiple layers of adhesive with light curing each successive layer,no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2(P>0.05).Conclusion Multiple coatings of one-step self-etching adhesive can increase the immediate bond strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

Effect of Saliva Contamination on Shear Bond Strength of Orthodontic Brackets When Using a Self-Etch Primer

The effect of saliva contamination on the shear bond strength of orthodontic brackets, at various stages of the bonding procedure using a new self-etch primer was studied. The samples were divided into 4 groups according to 4 different enamel surface conditions: Group A: dry; Group B: saliva contamination before priming; Group C: saliva contamination after priming, and Group D: saliva contamination before and after priming. Stainless steel brackets were bonded in each test group with a light-cured composite resin (TransbondXT 3M). The shear bond strength was determined in the first 30 min after bonding. The analysis of variance indicated that the shear bond strengths of the 4 groups were significantly different (F=11.89, P<0.05). Tukey HSD tests indicated that contamination both before and after the application of the acid-etch primer resulted in a significantly lower (=4.6±1.7 MPa) shear bond strength than either the control group (=8.8±1.9 MPa) or the groups where contamination occurred either before (=7.9±2.0 MPa) or after (=6.9±1.5 MPa) the application of the primer. It was concluded that the new acid-etch primer could maintain adequate shear bond strength if contamination occurred either before or after the application of the primer. On the other hand, contamination both before and after the application of the primer could significantly reduce the shear bond strength of orthodontic brackets.

Multiple Coatings can Improve the Bond Durability of One-step Self-etching Adhesive to Primary Dentin

Objective To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin. Methods Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instruc- tions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaC1 containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis. Results When the adhesive was applied three times before light curing, the bond strength of the ex- perimental subgroup 1 was significantly higher than that of the control subgroup 1 （47.46__＋13.91 vs. 38.12＋11.21 MPa, P〈O.05）. When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup （39.40＋8.87 vs. 40.87-＋9.33 MPa, P〉O.05）. Conclusion Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

A Study of the Impact of the Dissemination of Ancient Chinese Primer Classic in the United States

Carrying the roots of Chinese civilization to its origins,the Chinese Primer classic has received considerable attention in the international community’s cultural diffusion.The spread of the Chinese Primer class studies in the United States,aided by missionaries such as E.C.Bridgeman,Samuel Wells Williams,and William Alexander Parsons Martin,sinologists such as Witter Bynner and David Hinton,has been characterized by unidirectionality,permeability,and pluralism.

笋用林3种竹笋夜蛾多重PCR鉴定技术的建立与应用

【目的】建立鉴定竹笋夜蛾物种的多重PCR技术,用于浙江省笋用竹的3种竹笋夜蛾幼虫的物种鉴定。【方法】针对COI基因的变异区设计物种特异性多重PCR引物;优化影响多重PCR反应的参数,建立鉴定竹笋夜蛾的多重PCR技术;采用标准DNA模板评价多重PCR技术的敏感性和特异性;利用多重PCR技术对林间采集的竹笋夜蛾幼虫进行物种鉴定。【结果】针对3种竹笋夜蛾COI基因的变异区设计了3条物种特异性多重PCR引物,与通用引物LCO1490配合使用,扩增竹笋基夜蛾、竹笋禾夜蛾和笋秀夜蛾COI基因片段,大小分别为290、390和590 bp。优化后的多重PCR鉴定技术的反应体系为:2×HotStart Taq PCR预混试剂10μL,10μmol·L^(-1)的引物LCO1490、JYE290、HYE390和QTYE590各0.5μL,DNA模板1μL,加ddH2O补足20μL。优化后的多重PCR鉴定技术的反应条件为:94℃预变性5 min;94℃变性30 s,59℃退火30 s,72℃延伸30 s;72℃下延伸10 min,循环数为35。多重PCR鉴定技术对笋秀夜蛾的最低检出限为0.01 ng·μL^(-1),对竹笋禾夜蛾和竹笋基夜蛾的最低检出限低于0.001 ng·μL^(-1)。林间样品鉴定结果表明,所有38份DNA都能扩增出明显的特异性条带,鉴定成功率100%;经测序验证,本研究的技术鉴定的物种与经COI基因序列鉴定的物种一致。【结论】研究建立了浙江省笋用竹的夜蛾的多重PCR鉴定技术,能够快速高效鉴定浙江省笋用林内竹笋夜蛾幼虫的物种,该技术具有鉴定周期短、灵敏度高、特异性强、准确度高等优点。

国产飞机蒙皮底漆工艺适应性研究

为了验证国产飞机蒙皮底漆的工艺适应性,从壶装寿命、基材适用性、固化性能、底漆相容性以及面漆相容性等方面对该底漆展开了工艺研究。经过验证,国产飞机蒙皮底漆工艺性能够很好地适应现有民机材料施工要求。试验结果可以为该底漆的涂装工艺提供施工技术指导,具有重要的工程实践意义。

基于转录组测序的浙江楠EST-SSR分子标记开发

浙江楠是我国重要的珍稀濒危植物,开展浙江楠SSR位点分布特征及分子标记开发,可为浙江楠的资源评价和保护利用提供科学依据。研究基于高通量测序技术获得浙江楠转录组数据,利用生物信息学方法分析浙江楠转录组SSR位点,开发浙江楠SSR分子标记。结果表明,在浙江楠转录组中共获得116 582个SSR位点,SSR的发生频率为42.38%,平均距离为1.56 kb。浙江楠SSR位点以单核苷酸(63.42%)和二核苷酸重复(25.58%)为主,核苷酸优势基元优势重复基元排前三位的是A/T、AG/CT、AT/AT;SSR重复基元以10~20次重复为主,占总数的64.3%;SSR序列长度在10~646 bp之间,超过20 bp的SSR位点占SSR总数的29.05%,表明浙江楠转录组SSR位点具有较高的多态性。挑选96对SSR引物进行多态性检测,72对引物能够扩增出条带,扩增成功率为75%,最终开发到35对引物在浙江楠可检测到较高的遗传变异,丰富了楠属现有SSR分子标记。

应用PRIMER软件进行浮游植物群落结构的多元统计分析

根据青岛近海进行的一次添加营养盐的围隔实验数据,采用专业软件PRIMER中的多元统计分析方法,进行了浮游植物群落结构的变化研究。结果表明,虽然由于本实验中浮游植物的生长受到Si的限制,硅藻类群不占明显的优势,使得优势种随时间的变化不明显,没有出现明显的群落演替,但用PRIMER软件的聚类分析(Clustering)和多维尺度转换排序(MDS)分析表明,添加营养盐后浮游植物群落结构有较明显的变化,同时,PRIMER软件的相异系数(ANOSIM)分析也表明,在同时添加N、P的围隔内,浮游植物群落结构变化较只添加P的围隔中的变化显著。这显示了PRIMER软件在分析浮游植物群落结构变化和评价水域富营养化中的应用前景。

燕麦全基因组SSR位点鉴定及多态性标记开发

【目的】了解燕麦基因组SSR位点分布情况并开发燕麦全基因组SSR标记,为燕麦皮裸基因克隆、遗传图谱构建、群体多样性分析等提供科学的参考依据。【方法】利用已公布的“三分三”裸燕麦参考基因组,通过TBtools软件对燕麦全基因组的SSR位点进行检索并利用EXCEL和SPSS软件对检索数据分析其分布特征。根据检索结果设计引物,在构建的F_(2)遗传群体中小规模进行非变性聚丙烯酰胺凝胶电泳验证,并克隆测序其有效性与真实性。【结果】在燕麦基因组中,SSR数量众多,类型丰富。全基因组共检索到828138个SSR位点,SSR平均密度为78.16个/Mb,平均距离为12.90 kb。单、双、三核苷酸重复类型占主导优势。基元重复次数主要集中在5次和6次,A/T、AG/CT和AAC/GTT重复基元为优势基元。燕麦基因组SSR位点呈现中度多态性,长度变化范围为11-1587 bp。并由此开发设计52对多态性引物在试验材料中进行扩增验证,在构建的遗传群体中均具有多态性。【结论】在“三分三”裸燕麦参考基因组中开发SSR引物有效可行,可以用于后续进一步试验研究。

多元统计软件PRIMER在张网渔具种类选择性研究中的运用

本文根据2014年秋季青岛斋堂岛海域双桩竖杆张网的网囊网目选择性试验数据,运用PRIMER软件中的相似性分析、非参数多维标度分析和相似性百分比分析模块分析了张网渔具种类选择性。试验采用平行作业法,以传统网具(2a=16mm的菱形目网囊)作为对照网,设计了网目尺寸(2a)为30和35mm的菱形目网囊(以30D和35D表示)和网目尺寸(2a)为20、30和35mm的方形目网囊(以20S、30S和35S表示),进行选择性实验。研究显示:(1)35D、30S和35S渔获组成与对照网存在显著性差异,其余各网之间差异不显著。(2)改良后的试验网具能有效释放舒氏海龙;除20S组外,其余各试验网对方氏云鳚亦有较好的释放效果。(3)方形目网囊较相同尺寸的菱形目网囊具有更好的种类选择性;对相同网目形状的试验网囊进行比较,种类选择性随网目尺寸的增大而增大。(4)综合分析不同网具的渔获物组成和规格,在斋堂岛海域秋季小黄鱼、带鱼渔汛期,推荐使用30mm方形目网囊;方氏云鳚渔汛期,推荐使用20mm方形目网囊进行捕捞作业。研究结果表明,运用多元统计软件PRIMER进行张网渔具种类选择性分析虽然存在待完善之处,但该方法为本领域研究提供了有益参考。

适于多物种的通用尾巴序列设计及通用体系的建立

【目的】荧光毛细管电泳由于其检测通量高、分辨率高等优点,被广泛应用于个体鉴定、品种鉴定、物种鉴定等多种应用场景中。尾巴序列为荧光毛细管电泳平台的广泛应用提供了高效的解决方案。为解决已有尾巴序列无法满足多物种使用需求,本研究基于编码转译技术开发高效的通用尾巴序列(universal tailed-sequence,UTS)设计工具。基于此工具设计通用尾巴序列,构建适合多作物的通用型PCR体系和程序,提高荧光电泳通量和灵活性。【方法】基于编码转译技术开发高效的通用尾巴序列设计工具,并对3755个常用汉字进行编码转译,并设置序列GC含量、发卡结构及同源引物二聚体退火温度等筛选条件得到符合条件的UTS。使用BLAST工具对通用尾巴序列设计工具生成的UTS在多种生物基因组上进行同源性评估,并在玉米、番茄、辣椒、西瓜等作物上进行实验评估,构建物种通用型实验体系及程序。【结果】通过设计工具编码转译并筛选共得到7436833个高质量的候选UTS,占所有字组的52.74%。挑选6个UTS在20个作物基因组上的BLAST结果显示其与M13相比具有更好的特异性。通过对通用引物扩增程序进行优化,使通用引物在多个物种上的扩增成功率达到或超过95%,并具有较强的稳定性。【结论】利用编码转译技术开发通用尾巴序列,并为其搭配物种通用型扩增体系和程序,提供一种通量高、成本低的荧光电泳通用检测方法。

DNA Extraction and ISSR Primer Screening of Camellia chekiangoleosa

[Objective] The aim was to screen out simple methods of DNA extraction and effective ISSR primers suitable to all germplasm materials of Camellia chekiangoleosa.[Method] The modified CTAB method was used in the extraction of the genomic DNA,50 ISSR primers from other Camellia plants were used in the ISSR-PCR amplification for 20 germplasm materials from 10 populations in Fujian,Zhejiang,Jiangxi and Anhui Province.[Result] Pure DNA could be obtained rapidly by using the improved CTAB method,and the 20 selected effective primers had rich polymorphism,clear bands and good repeatability.337 DNA bands were obtained,of which 281 bands were polymorphic,accounting for 83.4% of the total amplified bands.And 16.85 bands could be amplified with a primer,averagely.[Conclusion] The selected 20 primers could be effectively applied to ISSR analysis of the germplasm resources of C.chekiangoleosa in Zhejiang.

利用软件Primer Premier 5.0进行PCR引物设计的研究

目的 运用PrimerPremier 5 0软件设计PCR引物 ,并且检验所设计引物的PCR扩增效率和特异性。方法 运用PrimerPremier 5 0软件设计 16对猪和犬的PCR扩增引物 ,通过PCR扩增后进行琼脂糖凝胶电泳检测实验结果。结果 在所设计的 16对引物中有 8对PCR扩增特异性好且效率高 ,成功率 5 0 %。但是 ,其中早期设计引物 12对只有 4对成功 ,后期设计引物 4对全部成功。结论 从引物设计的过程中可以看到一种趋势 -后期引物设计的成功率远远高于早期。这表明我们在引物设计方面正在逐步成熟 。

Designing Primers for H5 and H7 Subtypes of Avian Influenza Virus and Multiplex RT-PCR Amplification

[Objective] The research aimed to design primers that are suitable for detecting H5 and H7 subtypes of avian influenza virus （AIV） ; [Method] DNAStar was used to analyze the homology of the sequences of H5 and H7 subtypes of AIV accessed in GenBank, and design primers（ by Primer Premier 5.0） on high homologous region of these sequences, and then amplified by RT-PCR. [Result] The multiplex RT-PCR amplification, agarose gel electrophoresis and sequencing results showed that the self-designed primers are successful for detecting AIV. [Conclusion] It is feasible to rapidly diagnose AIV through this method.

广西道地药材肉桂及阴香的DNA分子鉴定研究

建立一种能够准确鉴别肉桂及阴香的特异性聚合酶链式反应方法,以保障肉桂用药的安全性和有效性。通过对比分析肉桂及阴香的psbA-trnH序列差异找到特异性单核苷酸多态性位点,设计特异性引物,通过优化退火温度、循环次数,评估不同聚合酶种类和不同基因扩增仪等扩增条件对不同来源的肉桂及阴香进行特异性扩增,根据特异性扩增条带进行鉴别。结果表明退火温度为54℃,循环次数为35次时,肉桂经肉桂特异性引物扩增后在100~200 bp处出现特异性条带,阴香无条带;退火温度为56℃,循环次数为40次时,阴香经阴香引物扩增后在200~300 bp处出现特异性条带,肉桂无条带。该研究所建立的特异性PCR方法可以快速准确鉴别出肉桂及阴香,为控制肉桂的质量安全提供参考。

利用MPprimer设计引物并优化扩增条件以提高多重PCR效率的实验研究

多重PCR技术广泛应用于多个研究领域,其中引物设计及扩增条件是提高多重PCR实验效率的关键因素.为探讨优化多重PCR实验的方法,以小鼠5个看家基因为研究对象,使用实验室新近开发的MPprimer程序设计多重PCR引物,并通过改变多种反应条件来优化多重PCR实验.结果表明,MPprimer程序能够设计出理想的多重PCR引物,并且通过对退火温度及延伸时间进行优化,可显著提高多重PCR实验效率,对于提高基因表达的规模化检测能力具有积极的促进作用.

Screening of SSR Core Primers for Purity Identification of Pepper(Capsicum) Hybrids

[Objective] This study aimed to screen a set of SSR core primers suitable for purity identification of pepper （Capsicum） hybrids. [Method] DNA fingerprint of 100 pepper hybrids was analyzed using 17 SSR primers. [Result] According to the polymorphism and heterozygosity, Hpms1-214, Es395 and Hpmsl-5 were determined as three preferred core primers for purity identification of pepper hybrids. By using these three preferred core primers, 97 pepper hybrids （accounting for 97%） had heterozygous band pattern with at least one primer. Es330, Es363, Epms923, Es120 and Es64 were determined as candidate core primers for purity identification of pepper hybrids. Specific primers of 14 varieties were obtained, which could be used to further screen parent-complementary primers of each pepper hybrid. [Con- clusion] This study laid the foundation for constructing standard DNA fingerprints for purity identification of pepper hybrids.

Primer Screening on Germplasm Resources of Mallotus oblongiolus by ISSR Molecular Marker

[ Objective] To provide effective primers for the rapid and accurate ISSR analysis of the germplasm materials of Mallotus oblongiolus （Miq.） Muello-Arg.. [Method] The modified CTAB method was used in the extraction of the genomic DNA. 99 ISSR primers were used in the ISSR-PCR amplification for 20 germplasm materials from 10 populations in Hainan Island, so that some primers, which were suitable to all gerplasm materials of M. oblongiolu, could be selected. [ Result] 15 effective primers with characteristics of rich polymorphism, clear bands, and good repeatability were selected from 99 test primers. The 15 primers selected were used in the ISSR-PCR amplification for 66 germplasm materials of M. oblongiolus. From all of which the abundant and distinct DNA fingerprintings could be obtained. 286 DNA bands were obtained, and of which 231 bands were polymorphic, which amounted to 80.77% of the total bands amplified. And 19.1 bands could be obtained with each primer, averagely. [ Conclusion] The 15 primers selected could be effectively applied to ISSR analysis of the germplasm resources of M. oblongiolus.