SEM, scanning electron microscope

SEM,扫描电子显微镜
  • 文章类型: Journal Article
    眼科手术和COVID-19患者中最常见的疾病是真菌性眼部感染,这可能会导致炎症和干眼症,并可能导致眼部发病。两性霉素B滴眼液通常用于治疗眼部真菌感染。乳铁蛋白是一种具有广谱抗微生物活性的铁结合糖蛋白,用于治疗干眼症,结膜炎,和眼部炎症。然而,不良的房水稳定性和过度的鼻泪管引流阻碍了这些药物的效率。这项研究的目的是检查两性霉素B的作用,作为抗白色念珠菌的抗真菌药,镰刀菌,还有黄曲霉,和乳铁蛋白,作为抗炎和抗干眼症,当共负载三嵌段聚合物PLGA-PEG-PEI纳米颗粒包埋在P188-P407眼科热敏凝胶中时。通过双乳液溶剂蒸发法制备纳米颗粒。优化后的配方显示粒径(177.0±0.3nm),多分散指数(0.011±0.01),ζ电位(31.9±0.3mV),和包封%(90.9±0.5),改善了离体药代动力学参数和离体角膜穿透性,与药物溶液相比。共聚焦激光扫描显示了氟标记的纳米颗粒的有价值的渗透。刺激试验(Draize试验),原子力显微镜,细胞培养和动物试验,包括组织病理学分析,揭示了纳米颗粒在减少炎症迹象和根除兔真菌感染方面的优越性。不会对兔子的眼球造成任何伤害。纳米颗粒表现出良好的药效学特征和持续释放曲线,并且在体外或体内既无细胞毒性也无刺激性。开发的配方可能为治疗眼部问题提供一种新的安全的纳米技术,比如炎症和真菌感染.
    The most prevalent conditions among ocular surgery and COVID-19 patients are fungal eye infections, which may cause inflammation and dry eye, and may cause ocular morbidity. Amphotericin-B eye drops are commonly used in the treatment of ocular fungal infections. Lactoferrin is an iron-binding glycoprotein with broad-spectrum antimicrobial activity and is used for the treatment of dry eye, conjunctivitis, and ocular inflammation. However, poor aqueous stability and excessive nasolacrimal duct draining impede these agens\' efficiency. The aim of this study was to examine the effect of Amphotericin-B, as an antifungal against Candida albicans, Fusarium, and Aspergillus flavus, and Lactoferrin, as an anti-inflammatory and anti-dry eye, when co-loaded in triblock polymers PLGA-PEG-PEI nanoparticles embedded in P188-P407 ophthalmic thermosensitive gel. The nanoparticles were prepared by a double emulsion solvent evaporation method. The optimized formula showed particle size (177.0 ± 0.3 nm), poly-dispersity index (0.011 ± 0.01), zeta-potential (31.9 ± 0.3 mV), and entrapment% (90.9 ± 0.5) with improved ex-vivo pharmacokinetic parameters and ex-vivo trans-corneal penetrability, compared with drug solution. Confocal laser scanning revealed valuable penetration of fluoro-labeled nanoparticles. Irritation tests (Draize Test), Atomic force microscopy, cell culture and animal tests including histopathological analysis revealed superiority of the nanoparticles in reducing signs of inflammation and eradication of fungal infection in rabbits, without causing any damage to rabbit eyeballs. The nanoparticles exhibited favorable pharmacodynamic features with sustained release profile, and is neither cytotoxic nor irritating in-vitro or in-vivo. The developed formulation might provide a new and safe nanotechnology for treating eye problems, like inflammation and fungal infections.
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  • 文章类型: Journal Article
    未经授权:在常规牙科实践中,牙本质超敏反应是影响成人的常见口腔疾病。虽然有多种治疗方法,没有单一的方法可以有效消除牙本质过敏并为患者提供完全的缓解。因此,本研究仅使用二极管激光并结合各种脱敏牙膏进行评估牙本质小管的闭塞,使用扫描电子显微镜。
    UNASSIGNED:这项体外研究由五组组成,其中在拔除的牙齿上准备宫颈腔,然后应用17%的EDTA。然后用Novamin牙膏处理空洞,前精氨酸牙膏,二极管激光器,并分别组合。然后进行SEM分析,并使用tukey的多重事后分析对获得的结果进行统计学分析,以进行组内和组间比较。
    UNASSIGNED:二极管激光和脱敏剂联合治疗组牙本质小管闭塞优于其他组(P<0.05)。
    UNASSIGNED:与脱敏型牙膏相比,使用二极管激光在治疗牙本质小管闭塞方面具有额外的益处。
    UNASSIGNED: In regular dental practice, dentinal hypersensitivity is a common oral condition affecting the adult population. Although a variety of treatment procedures are available, there is no single method that proved to be potent in eliminating dentine hypersensitivity and providing patients with complete relief. Hence the present study performed to estimate the occlusion of dentinal tubules using a diode laser alone and in combination with various desensitizing toothpaste, using the scanning electron microscope.
    UNASSIGNED: This in-vitro study consisted of five groups wherein cervical cavities were prepared on the extracted teeth followed by the application of 17% EDTA. The cavities were then treated with Novamin toothpaste, pro-arginine toothpaste, diode laser, and in combinations respectively. Then SEM analysis was done and the results obtained were statistically analyzed using tukey\'s multiple post hoc analysis for intra and inter group comparisons.
    UNASSIGNED: The groups which were treated with a combination of diode laser and the desensitizing agent showed statistically significant (P < 0.05) better dentinal tubule occlusion than other groups.
    UNASSIGNED: The use of a diode laser has an added benefit in treating dentinal tubule occlusion when compared to desensitizing kinds of toothpaste.
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  • 文章类型: Journal Article
    紫色非硫细菌(PNSB)对于生物炼制应用以创建生物分子感兴趣,但是由于底物和生物质分离成本,它们的生产成本是昂贵的。这项研究利用燃料合成废水(FSW)作为一种低成本的富含碳的基质来生产单细胞蛋白(SCP),并使用这种基质来研究PNSB生物膜的形成,以实现更有效的生物质-液体分离。在这项研究中,PNSB生长在Ca,Mg,S,P,和使用绿色阴影作为生物膜支持材料的N缺乏培养基。在这些营养条件中,只有氮缺乏和控制(营养充足)条件显示生物膜形成。尽管对照的总生物量增长是缺氮条件的1.5倍,总体最高,缺氮条件下的总生物膜生物量是对照的2.5倍,占生产总生物量的49%。这四个生物质样品的总蛋白质含量相似,范围从35.0±0.2%到37.2±0.0%。在缺镁条件下(仅悬浮生物量),蛋白质含量最高,为44.7±1.3%,但生长速率低。总的来说,营养充足的条件对于整体蛋白质生产率是最佳的,并且以悬浮生长为主导,但是在需要固定生长系统来实现具有成本效益的收获的地方,缺乏N的条件提供了一种有效的手段来最大化生物膜的产生而不牺牲蛋白质含量。
    Purple non-sulphur bacteria (PNSB) are of interest for biorefinery applications to create biomolecules, but their production cost is expensive due to substrate and biomass separation costs. This research has utilized fuel synthesis wastewater (FSW) as a low-cost carbon-rich substrate to produce single-cell protein (SCP) and examines PNSB biofilm formation using this substrate to achieve a more efficient biomass-liquid separation. In this study, PNSB were grown in Ca, Mg, S, P, and N-deficient media using green shade as biofilm support material. Among these nutrient conditions, only N-deficient and control (nutrient-sufficient) conditions showed biofilm formation. Although total biomass growth of the control was 1.5 times that of the N-deficient condition and highest overall, the total biofilm-biomass in the N-deficient condition was 2.5 times greater than the control, comprising 49% of total biomass produced. Total protein content was similar between these four biomass samples, ranging from 35.0 ± 0.2% to 37.2 ± 0.0%. The highest protein content of 44.7 ± 1.3% occurred in the Mg-deficient condition (suspended biomass only) but suffered from a low growth rate. Overall, nutrient sufficient conditions are optimal for overall protein productivity and dominated by suspended growth, but where fixed growth systems are desired for cost-effective harvesting, N-deficient conditions provide an effective means to maximize biofilm production without sacrificing protein content.
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  • 文章类型: Journal Article
    这项研究评估了包封的德氏乳杆菌亚种的活力。储存和体外胃肠道运输过程中巧克力中的保加利亚。还评估了胃肠道运输过程中的类黄酮含量和短链脂肪酸(SCFA)的产生。封装的德氏乳杆菌亚种。在4°C和25°C下储存120天后,保加利亚在巧克力>7个日志中存活良好,在体外胃肠运输过程中。通过体外胃肠道消化和结肠发酵释放SCFA表明,益生菌巧克力可能是肠道微生物群的极好营养来源。含有70%可可的巧克力中的益生菌产生显著(P<0.05)更多的乙酸,丙酸,异丁酸,丁酸和异戊酸比含45%可可。德氏乳杆菌亚种对特定多酚的生物转化结果。保加利亚表明巧克力多酚可以被益生菌用于代谢。这些发现证实,巧克力可以成功地用德氏乳杆菌亚种强化。保加利亚封装,以改善巧克力的健康促进特性。
    This study evaluated the viability of encapsulated Lactobacillus delbrueckii subsp. bulgaricus in chocolate during storage and in-vitro gastrointestinal transit. Flavonoid contents and short chain fatty acids (SCFAs) production during gastrointestinal transit were also assessed. Encapsulated L. delbrueckii subsp. bulgaricus survived well in chocolates >7 logs both after 120 days of storage at 4 °C and 25 °C, and during in-vitro gastrointestinal transit. The release of SCFAs through in-vitro gastrointestinal digestion and colonic fermentation revealed that probiotic-chocolates could be an excellent source of nutrients for the gut microbiota. Encapsulated probiotic in chocolates with 70% cocoa produced significantly (P < 0.05) more acetic, propionic, isobutyric, butyric and isovaleric acids than that with 45% cocoa. The bioconversion results of a specific polyphenol by L. delbrueckii subsp. bulgaricus exhibited that chocolate polyphenols could be utilized by probiotics for their metabolism. These findings confirmed that chocolate could be successfully fortified with L. delbrueckii subsp. bulgaricus encapsulation to improve health promoting properties of chocolates.
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  • 文章类型: Journal Article
    由于自我修复能力有限,大型骨缺损修复是一个具有挑战性的临床问题。精心设计的骨填充产品应具有诱导组织向内生长并促进新血管形成和新骨形成的能力。葛根素已经在临床上使用了很长时间,最近发现它能够促进成骨。本研究旨在探讨以葛根素为基础的药物/递送组合植入物促进大型骨缺损修复。
    将葛根素掺入聚(乳酸-羟基乙酸共聚物)/β-磷酸钙(PLGA/TCP,PT)采用低温快速成型技术形成多孔PLGA/TCP/葛根素(PTP)复合支架。体外分析了其结构和降解。然后我们采用大鼠颅骨临界尺寸缺损模型来评估PTP支架的效力。MC3T3-E1细胞和EA.Hy926个细胞用于研究其潜在机制。
    PTP支架继承了PT支架在结构、机械,和生物降解,同时葛根素从PTP支架中稳定持续释放,并在体外持续5个月。植入后8周,PTP支架在支架的大孔和支架内部引发了新的骨形成,并伴随着降解材料。其潜在机制揭示了PTP支架通过刺激血管内皮生长因子(VEGF)和骨形态发生蛋白2(BMP-2)的表达促进血管生成和成骨,从而诱导血管浸润和募集修复细胞。
    富含葛根素的多孔PTP支架是一种有前途的局部递送系统,可持续释放葛根素,通过协同血管生成和成骨作用促进缺损修复。
    PTP支架为大型骨缺损修复提供了潜在的药物/设备组合医疗植入物,这也为“老药”葛根素提供了新的创新应用。
    UNASSIGNED: Large bone defect repair is a challenging clinical problem due to limited self-repair ability. A well-designed bone filling product should possess the ability to induce tissue in-growth and facilitate neovascularization and new bone formation. Puerarin has been used in clinics for a long time, and recently it was found to be able to promote osteogenesis. This study aimed to investigate a puerarin-based drug/delivery combination implant for promoting large bone defect repair.
    UNASSIGNED: Puerarin was incorporated into the poly (lactic-co-glycolic acid)/β-calcium phosphate (PLGA/TCP, PT) to form a porous PLGA/TCP/Puerarin (PTP) composite scaffold by low-temperature rapid prototyping technology. Its structural and degradation were analyzed in vitro. Then we employed a rat calvarial critical size defect model to assess the potency of the PTP scaffold. MC3T3-E1 cells and EA. hy 926 ​cells were used to investigate the underlying mechanism.
    UNASSIGNED: PTP scaffold inherited all advantages of PT scaffold in structural, mechanical, and biodegradation, meanwhile puerarin stably and continuously released from PTP scaffold and lasted for 5 months in vitro. At 8 weeks after implantation, the PTP scaffold triggered new bone formation in the macro-pores of the scaffold and inside the scaffold accompanied by the degrading materials. The underlying mechanism revealed that the PTP scaffold induced vascular infiltration and recruit repair cells through stimulating vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) expressions to promote angiogenesis and osteogenesis.
    UNASSIGNED: Puerarin-enriched porous PTP scaffold was a promising local delivery system with sustained release of puerarin for facilitating defect repair through getting synergistic angiogenic and osteogenic effects.
    UNASSIGNED: The PTP scaffold presents a potential drug/device combination medical implant for large bone defect repair, which also provides a new and innovative application for the \"old drug\" puerarin.
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  • 文章类型: Journal Article
    巴豆(Prunoi)叶积累了几种二萜,并具有各种药理活性。本研究旨在准备,表征和评估通过混合plaunotol(PL)或plaunoi提取物(PE)与环糊精(CD)制备的包合物的抗菌活性,包括α-CD,β-CD,γ-CD,和羟丙基-β-环糊精(HP-β-CD)。使用SEM对包合物进行了表征,XRD,DSC,和FT-IR,并评价其水溶性和热稳定性。进一步评价具有HP-β-CD的PL和PE冻干复合物对引起痤疮的细菌的抗菌活性。PL的最低抑菌浓度(MIC)和最低杀菌浓度(MBC),PE,使用琼脂稀释法评估的包合物表明,包合物的MIC和MBC值低于单独的PL或PE。有趣的是,用棋盘法测试后,复合物与克林霉素具有协同活性。使用琼脂孔扩散法评估含有包合复合物和克林霉素的水凝胶的抗菌活性。结果表明,水凝胶对细菌生长有明显的抑制作用。总之,制备的含HP-β-CD的PL或PE固体分散体可通过增加药物溶解度来增强抗菌活性。含有PL或PE复合物和克林霉素的水凝胶可以被认为是治疗寻常痤疮的候选物。
    Croton stellatopilosus (Plaunoi) leaves accumulate several diterpenes and possess various pharmacological activities. The present study aimed to prepare, characterize and assess the antibacterial activity of inclusion complexes prepared by mixing plaunotol (PL) or plaunoi extract (PE) with cyclodextrins (CD), including α-CD, β-CD, γ-CD, and hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexes were characterized using SEM, XRD, DSC, and FT-IR and evaluated for aqueous solubility and thermal stability. The PL and PE lyophilized complexes with HP-β-CD were further evaluated for their antibacterial activity against acne-causing bacteria. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of PL, PE, and the inclusion complexes evaluated using the agar dilution method revealed that the MIC and MBC values of the inclusion complexes were lower than those of PL or PE alone. Interestingly, the complexes had a synergistic activity with clindamycin after testing with checkerboard assay. The hydrogel containing the inclusion complex and clindamycin were assessed for antibacterial activity using the agar well diffusion method. The results indicated that the hydrogels showed significant inhibition of bacterial growth. In conclusion, the prepared solid dispersion of PL or PE with HP-β-CD could enhance antibacterial activity by increasing the drug solubility. The hydrogels containing PL or PE complex and clindamycin could be considered as a candidate for the treatment of acne vulgaris.
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  • 文章类型: Journal Article
    纳米级定位在学术界和工业界都有许多应用。越来越多的应用需要具有长工作距离和纳米级分辨率的设备。摩擦惯性压电定位器,基于粘滑机制,实现纳米分辨率和厘米尺度的旅行。然而,复杂的预加载机制的要求,精密加工,和精确的组装增加了传统的摩擦惯性纳米定位器的成本。本文介绍了开源XYZ轴纳米定位系统的设计。利用基于磁铁的粘滑驱动机构,拟议的XYZ纳米定位器提供了几个优点,包括亚纳米分辨率,最大12公斤(水平)的有效载荷能力,紧凑的尺寸,低成本,易于组装;此外,该系统是无需调整的。性能测试验证了系统在扫描和步进操作模式下的精度。此外,共振谱肯定了机构的刚度和动力响应。此外,我们展示了这种纳米定位器在各种测量技术中的实际应用,包括扫描电子显微镜,测振法,和原子力显微镜。此外,我们介绍了与超高真空系统和其他现有系统兼容的纳米定位器设计的11种变体,3D打印,或黑客商业线性幻灯片。
    Nanoscale positioning has numerous applications in both academia and industry. A growing number of applications require devices with long working distances and nanoscale resolutions. Friction-inertia piezoelectric positioners, which are based on the stick-slip mechanism, achieve both nanometer resolution and centimeter-scale travel. However, the requirements of complex preload mechanism, precision machining, and precise assembly increase the cost of conventional friction-inertia nanopositioners. Herein we present the design of an open-source XYZ-axis nanopositioning system. Utilizing a magnet-based stick-slip driving mechanism, the proposed XYZ nanopositioner provides several advantages, including sub-nanometer resolution, a payload capacity of up to 12 kg (horizontal), compact size, low cost, and easy assembly; furthermore, the system is adjustment-free. The performance tests validate the precision of the system in both scanning and stepping operation modes. Moreover, the resonant spectra affirm the rigidity and dynamic response of the mechanism. In addition, we demonstrate the practical applications of this nanopositioner in various measurement techniques, including scanning electron microscopy, vibrometry, and atomic force microscopy. Furthermore, we present 11 variations of the nanopositioner designs that are either compatible with ultra-high-vacuum systems and other existing systems, 3D printable, or hacking commercial linear slides.
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  • 文章类型: Journal Article
    未经证实:有效诱导了耳斑点图,内耳的发育起源来自人类多能干细胞(hPSC),为耳部发育和感音神经性听力损失建模提供了一个强大的平台。然而,通过逐步分化方法,hPSC的耳谱系规范能力有限,因为成功的耳细胞分化的关键因素尚未被彻底研究。在这项研究中,我们开发了一种新的分化系统,涉及使用具有信号因子的三维(3D)漂浮培养物,通过hPSC的逐步分化产生耳细胞谱系。
    未经证实:我们在二维(2D)单层培养下将hPSC分化为前位细胞。然后,我们在成纤维细胞生长因子(FGF)的控制下,将诱导的前位细胞转移到3D漂浮培养物中,骨形态发生蛋白(BMP),维甲酸(RA)和WNT信号通路。我们使用免疫细胞化学评估了诱导细胞的特征,定量PCR(qPCR),人口平均,和单细胞RNA-seq(RNA-seq)分析。我们进一步研究了通过定义的转录因子的过表达使耳祖细胞向毛细胞分化的方法。
    UNASSIGNED:我们证明了hPSC衍生的前胎盘细胞在FGF2和RA的3D漂浮培养中获得了分化成后胎盘细胞的潜力。随后WNT信号的激活诱导耳胎盘细胞形成。通过单细胞RNA-seq(scRNA-seq)分析,我们在诱导的球体中鉴定出多个成簇的耳斑状细胞和耳囊标记阳性细胞.此外,诱导的耳细胞显示出通过转录因子ATOH1,POU4F3和GFI1的过表达产生毛细胞样细胞的潜力。
    UNASSIGNED:我们证明了FGF2、RA和WNT信号传导在3D环境中对于来自hPSC的耳谱系细胞的体外分化的关键作用。诱导的耳细胞具有分化成具有立体睫状束和尖端链状结构的内耳毛细胞的能力。该方案将用于感音神经性听力损失和人类内耳发育的体外疾病建模,从而有助于药物筛选和基于干细胞的再生医学。
    UNASSIGNED: Efficient induction of the otic placode, the developmental origin of the inner ear from human pluripotent stem cells (hPSCs), provides a robust platform for otic development and sensorineural hearing loss modelling. Nevertheless, there remains a limited capacity of otic lineage specification from hPSCs by stepwise differentiation methods, since the critical factors for successful otic cell differentiation have not been thoroughly investigated. In this study, we developed a novel differentiation system involving the use of a three-dimensional (3D) floating culture with signalling factors for generating otic cell lineages via stepwise differentiation of hPSCs.
    UNASSIGNED: We differentiated hPSCs into preplacodal cells under a two-dimensional (2D) monolayer culture. Then, we transferred the induced preplacodal cells into a 3D floating culture under the control of the fibroblast growth factor (FGF), bone morphogenetic protein (BMP), retinoic acid (RA) and WNT signalling pathways. We evaluated the characteristics of the induced cells using immunocytochemistry, quantitative PCR (qPCR), population averaging, and single-cell RNA-seq (RNA-seq) analysis. We further investigated the methods for differentiating otic progenitors towards hair cells by overexpression of defined transcription factors.
    UNASSIGNED: We demonstrated that hPSC-derived preplacodal cells acquired the potential to differentiate into posterior placodal cells in 3D floating culture with FGF2 and RA. Subsequent activation of WNT signalling induced otic placodal cell formation. By single-cell RNA-seq (scRNA-seq) analysis, we identified multiple clusters of otic placode- and otocyst marker-positive cells in the induced spheres. Moreover, the induced otic cells showed the potential to generate hair cell-like cells by overexpression of the transcription factors ATOH1, POU4F3 and GFI1.
    UNASSIGNED: We demonstrated the critical role of FGF2, RA and WNT signalling in a 3D environment for the in vitro differentiation of otic lineage cells from hPSCs. The induced otic cells had the capacity to differentiate into inner ear hair cells with stereociliary bundles and tip link-like structures. The protocol will be useful for in vitro disease modelling of sensorineural hearing loss and human inner ear development and thus contribute to drug screening and stem cell-based regenerative medicine.
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  • 文章类型: Journal Article
    UNASSIGNED:涂层-厚度相关的物理性质可以用物理气相沉积(PVD)氮化钛铝(TiAlN)陶瓷涂层刀具诱导不同的切削温度。最优TiAlN涂层厚度的测定重要是为了取得优越的涂层物理机能和下降Inconel718合金的切削温度。
    UNASSIGNED:本研究研究了Inconel718合金加工过程中涂层厚度对TiAlN涂层物理性能和切削温度的影响。还确定了最佳涂层厚度。
    未经批准:首先,直流电弧方法用于沉积厚度为1.6µm的PVDTi0.55Al0.45N涂层,2µm,2.5µm,和3μm,在硬质合金基材上。第二,用雷达图表征和估计了与涂层厚度相关的物理性质。第三,用PVDTiAlN涂层刀具切削Inconel718时,用刀屑摩擦系数分析了涂层厚度对涂层减摩性能的影响。测量了切屑中产生的最高切削温度和刀具本体的切削温度,以分析涂层的热障效应。最后,获得并研究了变形切屑的形貌和刀具-切屑接触面积,以确定涂层厚度对切削温度的影响。
    UNASSIGNED:刀屑摩擦系数和涂层热障效应受涂层厚度的影响。涂层厚度适中的Ti0.55Al0.45N涂层工具与Inconel718具有良好的减摩效果。Ti0.55Al0.45N涂层的热障效应与涂层厚度呈正相干。
    UNASSIGNED:确定最佳TiAlN涂层厚度为2μm,这导致优异的物理性能和降低Inconel718的切削温度。
    UNASSIGNED: Coating-thickness-dependent physical properties can induce different cutting temperatures with physical vapor deposition (PVD) titanium aluminum nitride (TiAlN) ceramic-coated tools. The determination of the optimal TiAlN coating thickness is important to obtain superior coating physical properties and decrease the cutting temperature of Inconel 718 alloy.
    UNASSIGNED: The present study investigates the effects of coating thickness on the physical properties of TiAlN coatings and the cutting temperature during the machining of Inconel 718 alloy. The optimal coating thickness is also determined.
    UNASSIGNED: First, the direct-current-arc method was utilized to deposit PVD Ti0.55Al0.45N coatings with thickness of 1.6 µm, 2 µm, 2.5 µm, and 3 µm, onto a cemented carbide substrate. Second, the coating-thickness-dependent physical properties were characterized and estimated with a radar chart. Third, the effects of coating thickness on coating antifriction were analyzed with the tool-chip friction coefficient when cutting Inconel 718 with PVD TiAlN coated tools. Both the maximum cutting temperature generated in the chip and the cutting temperature of the tool bodies were measured for analyzation of the thermal barrier effect of coating. Finally, the topographies of the deformed chip and tool-chip contact area were obtained and investigated to determine the effects of coating thickness on the cutting temperature.
    UNASSIGNED: The tool-chip friction coefficient and coating thermal barrier effect were affected by the coating thickness. Ti0.55Al0.45N coated tools with moderate coating thickness had fine antifriction effect with Inconel 718. The thermal barrier effect of Ti0.55Al0.45N coating was positively related to the coating thickness.
    UNASSIGNED: The optimal TiAlN coating thickness was determined as 2 μm, which resulted in superior physical properties and reduced the cutting temperature of Inconel 718.
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  • 文章类型: Journal Article
    尿路病原体在导尿管上形成生物膜,导致与抗微生物治疗耐药性相关的持续性和慢性感染。因此,本研究通过测定乳酸菌(LAB)对抗多药耐药(MDR)尿路病原体的抗生物膜能力,来控制生物膜相关尿路感染.从泡菜和发酵乳制品中获得20个LAB,并筛选了它们对MDR大肠杆菌U12(ECU12)的抗生物膜和抗菌作用。植物乳杆菌Y3(LPY3)(MT498405),表现出最高的抑制作用和生物膜的产生。用LPY3培养物预包被微量滴定板比共孵育更有效。与无细胞上清液(CFS)(31.2%)相比,用LPY3培养物预包被产生更高的抗生物膜作用,粘附率为14.5%。CFS的抗生物膜作用在高达100°C下是热稳定的,在pH4-6下具有更高的作用。用LPY3培养物预涂覆导尿管可降低附着在导尿管上的ECU12的CFU/cm2长达7天。同时,CFS降低ECU12CFU/cm2达4天。扫描电子显微镜证实,在用CFS治疗后,ECU12对导管的粘附性降低。因此,植物乳杆菌可作为预防剂和天然生物干预剂应用于医疗设备中以治疗尿路感染。
    Uropathogens develop biofilms on urinary catheters, resulting in persistent and chronic infections that are associated with resistance to antimicrobial therapy. Therefore, the current study was performed to control biofilm-associated urinary tract infections through assaying the anti-biofilm ability of lactic acid bacteria (LAB) against multidrug-resistant (MDR) uropathogens. Twenty LAB were obtained from pickles and fermented dairy products, and screened for their anti-biofilm and antimicrobial effects against MDR Escherichia coli U12 (ECU12). Lactobacillus plantarum Y3 (LPY3) (MT498405), showed the highest inhibitory effect and biofilm production. Pre-coating of a microtitre plate with LPY3 culture was more potent than co-incubation. Pre-coating with LPY3 culture generated a higher anti-biofilm effect with an adherence of 14.5% than cell free supernatant (CFS) (31.2%). Anti-biofilm effect of CFS was heat stable up to 100 °C with higher effect at pH 4-6. Pre-coating urinary catheter with LPY3 culture reduced the CFU/cm2 of ECU12 attached to the catheter for up to seven days. Meanwhile, CFS reduced the ECU12 CFU/cm2 for up to four days. Scanning electron microscope confirmed the reduction of ECU12 adherence to catheters after treatment with CFS. Therefore, Lactobacillus plantarum can be applied in medical devices as prophylactic agent and as a natural biointervention to treat urinary tract infections.
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