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Prevalence of Staphylococcus aureus and antibiotic resistant Staphylococcus aureus in public transport in Bratislava, Slovakia 斯洛伐克布拉迪斯拉发公共交通中金黄色葡萄球菌和耐药金黄色葡萄球菌的流行情况
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0007
A. Medveďová, Romana Györiová
Abstract There is evidence that the transmission of Staphylococcus aureus and methicillin-resistant S. aureus between the community and environmental surfaces still exists. Even the means of this transmission remain uncertain, the public transport system may serve as a potential source of different bacteria, and the contact with contaminated public surfaces may increase the risk for bacterial diseases emergence. This study aimed to investigate S. aureus contamination on Bratislava’s public transport vehicles. Forty samples of hand-touched surfaces were collected during December 2015 and March 2017 by using surface sampling method. S. aureus was detected in all analysed swabs. Simultaneously, antibiotic resistance of S. aureus from swabs was evaluated. Of 40 samples, only 23 % did not contain S. aureus resistant to some of 10 analysed antibiotics. On the other hand, the severe prevalence of highly resistant S. aureus to penicillin, methicillin, ampicillin, and cefoxitin was confirmed. 15 % of isolates displayed resistance to at least three antimicrobial classes. The amount of S. aureus was not significantly influenced by the lines or by the analysed surface (grabs rails or on-board stop buttons). However, there was a statistically significant effect of year period, both between samples from December and March and between samples from the same month but different year. The study confirmed the widespread occurrence of resistant S. aureus in public transport vehicles in Bratislava, Slovakia.
有证据表明,金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌在社区和环境表面之间的传播仍然存在。即使这种传播途径仍不确定,公共交通系统也可能是不同细菌的潜在来源,与受污染的公共表面接触可能增加出现细菌性疾病的风险。本研究旨在调查布拉迪斯拉发公共交通车辆的金黄色葡萄球菌污染情况。2015年12月至2017年3月,采用表面采样法采集手触表面样本40份。所有拭子均检出金黄色葡萄球菌。同时对拭子金黄色葡萄球菌的耐药性进行评估。在40个样本中,只有23%的样本不含对所分析的10种抗生素中的一些具有耐药性的金黄色葡萄球菌。另一方面,证实了对青霉素、甲氧西林、氨苄西林和头孢西丁高度耐药的金黄色葡萄球菌的严重流行。15%的分离株显示出对至少三种抗菌素类的耐药性。金黄色葡萄球菌的数量不受线路或分析表面(抓轨或车上停止按钮)的显著影响。然而,无论是12月和3月的样本之间,还是同月不同年份的样本之间,年份的影响都具有统计学意义。该研究证实,在斯洛伐克布拉迪斯拉发的公共交通工具中广泛存在耐药金黄色葡萄球菌。
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引用次数: 1
Electrolytic colouring of anodized aluminium on tin basis 锡基阳极氧化铝的电解着色
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0002
Barbora Šopová, M. Zemanová
Abstract The aim of the study was to find parameters of electrolytic colouring on tin basis to form uniform black coatings on anodized aluminium. A two steps electrolytic process consisting of aluminium anodization in a sulphuric acid electrolyte and colouring in tin acidic electrolyte was used. Among parameters influencing the colouring process, AC colouring voltage, composition of the counter electrode and agitation of the colouring electrolyte were studied. Spectrocolorimetry was applied to analyse the quality of the colouring. Thickness of the coloured and sealed anodized specimens was also evaluated. Optimal parameters for uniform colouring of anodized specimens were found. Unfortunately, colouring electrolyte on tin basis is susceptible to oxidation which negatively influences the colouring.
摘要本研究的目的是寻找锡基电解着色的参数,以在阳极氧化铝上形成均匀的黑色涂层。采用两步电解工艺,包括在硫酸电解液中进行铝阳极氧化和在锡酸性电解液中着色。在影响着色过程的参数中,研究了交流着色电压、对电极的组成和着色电解质的搅拌。采用分光光度法对色素的质量进行了分析。着色和密封阳极氧化试样的厚度也进行了评估。找到了阳极氧化试样均匀着色的最佳参数。不幸的是,以锡为基础的着色电解质容易被氧化,这对着色产生负面影响。
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引用次数: 0
Trichoderma atroviride: an isolate from forest environment with secondary metabolites with high antimicrobial potential 萎缩木霉:一个来自森林环境的具有高抗菌潜力的次级代谢产物的分离物
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0008
J. Víglaš, P. Olejníková
Abstract This work was focused on the characterization of novel isolate of Trichoderma atroviride O1, found in the forest around the village of Zázrivá (the Northern Slovakia, region Orava). The isolate was identified by sequencing its internal transcribed spacer (ITS) region of rDNA. T. atroviride O1 stimulated the development of lateral roots of model plant Lepidium sativum. Simultaneously, the isolate has proved its high mycoparasitic potential as it displayed the ability to attack colonies of phytopathogenic fungi (Alternaria alternata, Fusarium culmorum, Botrytis cinerea). This isolate produced secondary metabolites, which were isolated and tested for the antimicrobial activity against gram-positive bacteria Staphylococcus epidermidis and Staphylococcus aureus. The growth of these bacteria was suppressed to 10 % and 40 %, respectively. The suppression of the growth of two Candida species was also strong (10 % growth). However, growth parameters of three phytopathogenic fungi (Alternaria alternata, Botrytis cinerea and Fusarium culmorum) were less affected (75 % growth in comparison with the control). Attempts were made to characterize secondary metabolites isolated from T. atroviride O1. Known peptaibols, 20—21 amino acid long, but also shorter peptides, were detected by MALDI-TOF mass spectrometry. Thus, this study demonstrates the plant growth promotion, strong mycoparasitic potential and antimicrobial activity of the isolate T. atroviride O1, which could be in part ascribed to the production of secondary metabolites. This isolate does have a potential in the biocontrol in eco-farming. Further study, particularly, the identification of produced secondary metabolites, is needed.
摘要这项工作的重点是在Zázrivá村(斯洛伐克北部,奥拉瓦地区)周围的森林中发现的新分离的萎缩性木霉O1的特征。通过对其rDNA的内部转录间隔区(its)进行测序来鉴定该分离物。T.atroviride O1刺激了模式植物Lepidium sativum侧根的发育。同时,该分离株已证明其具有很高的真菌寄生潜力,因为它显示出攻击植物病原真菌(Alternaria alternata、Fusarium tumorum、Botrytis cinerea)菌落的能力。该分离物产生次级代谢产物,分离并测试其对革兰氏阳性菌表皮葡萄球菌和金黄色葡萄球菌的抗菌活性。这些细菌的生长分别被抑制到10%和40%。对两种念珠菌的生长也有很强的抑制作用(10%的生长)。然而,三种植物病原真菌(Alternaria alternata、Botrytis cinerea和Fusarium culmorum)的生长参数受到的影响较小(与对照相比生长75%)。尝试鉴定从T.atroviride O1中分离的次级代谢产物。通过MALDI-TOF质谱法检测到已知的蛋白胨,20-21个氨基酸长,但也有较短的肽。因此,本研究证明了分离物T.atroviride O1的植物生长促进作用、强大的分枝寄生潜力和抗菌活性,这在一定程度上可归因于次级代谢产物的产生。这种分离物在生态农业的生物防治中确实具有潜力。需要进一步研究,特别是鉴定产生的次级代谢产物。
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引用次数: 2
Recombinant human erythropoietin separation using a cation-exchange multimodal adsorbent 用阳离子交换多模态吸附剂分离重组人促红细胞生成素
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0015
Marta Ostrihoňová, Jana Adamíková, T. Molnár, M. Antošová, M. Polakovič
Abstract This work deals with the capture of human recombinant erythropoietin (rhEPO) from a mixture of proteins in a concentrated postcultivation supernatant. Cation-exchange multimodal adsorbent Capto MMC ImpRes was selected as potential chromatographic separation material. Its equilibrium properties were investigated in batch adsorption experiments. The effect of pH in the range of 5.5—7.5 and NaCl concentration in the range of 0—300 mM on the adsorption of rhEPO and contaminant proteins was examined. Optimal conditions found in these equilibrium experiments were applied to rhEPO adsorption in a chromatographic column. Several experiments were carried out at different elution conditions to optimize the rhEPO yield and selectivity.
摘要:本工作涉及从浓缩培养后上清中的混合蛋白中捕获人重组红细胞生成素(rhEPO)。选择阳离子交换多模态吸附剂Capto MMC ImpRes作为潜在的色谱分离材料。通过间歇吸附实验研究了其平衡性能。考察了pH在5.5 ~ 7.5范围内、NaCl浓度在0 ~ 300 mM范围内对rhEPO和污染物蛋白吸附的影响。在这些平衡实验中找到的最佳条件适用于rhEPO在色谱柱上的吸附。在不同的洗脱条件下,对rhEPO的收率和选择性进行了优化。
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引用次数: 0
Sewage sludge as a source of triclosan-resistant bacteria 污水污泥是耐三氯生细菌的来源
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0006
Kristína Lépesová, Monika Krahulcová, T. Mackuľak, L. Bírošová
Abstract Subinhibitory concentrations of antibiotics and biocides in wastewaters and sewage sludge have a great impact on the development of antibiotic resistance and its spread among bacteria. The aim of this work was to determine the occurrence of coliform bacteria and enterococci resistant to biocide triclosan in samples of sewage sludge. Subsequently, isolated strains of coliform bacteria were identified and characterized in terms of their antibiotic susceptibility and ability to form a biofilm. Occurrence of the studied bacteria was monitored in three samples of stabilized sludge from three different wastewater treatment plants (Vrakuňa, Petržalka, and Senec). The number of triclosan-resistant coliforms was the highest in the sludge sample from the wastewater treatment plant in Senec and the lowest in the sludge sample from the wastewater treatment plant in Petržalka. Triclosan-resistant Enterococcus spp. were not found in any sample of stabilized sludge. Most isolates were identified as Citrobacter freundii and Serratia spp. Triclosan-resistant isolates showed also resistance to antibiotics and the majority of them were strong biofilm producers.
摘要废水和污泥中抗生素和杀菌剂的亚抑制浓度对抗生素耐药性的发展及其在细菌中的传播有很大影响。本研究的目的是测定污水污泥样品中大肠菌群和对杀菌剂三氯生耐药肠球菌的发生情况。随后,对分离的大肠菌群菌株进行了鉴定,并根据其抗生素敏感性和形成生物膜的能力进行了表征。在三个不同污水处理厂(Vrakuňa, Petržalka和Senec)的三个稳定污泥样本中监测所研究细菌的发生情况。耐三氯生大肠菌群数量以Senec污水处理厂的污泥样品最多,Petržalka污水处理厂的污泥样品最少。稳定污泥样品中未发现三氯生耐药肠球菌。大多数分离株鉴定为弗氏柠檬酸杆菌和沙雷氏菌,耐三氯生的分离株对抗生素也有耐药性,大多数是强生物膜产生菌。
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引用次数: 4
Analysis of C3 fraction splitting system performance by mathematical modeling in MATLAB environment MATLAB环境下C3馏分裂解系统性能的数学建模分析
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0018
Miroslav Variny, Patrik Furda, N. Kováč, O. Mierka
Abstract Propane-propylene mixture splitting by industrial conventional rectification incorporating a heat pump for energy intensity decrease was modeled in the Matlab environment. The constructed model was verified by comparing its results with operational data of a real C3 fraction splitting unit. As documented, increased product quality can be obtained at zero additional costs due to specific features of the system design. Process capacity and product purity limitations have to be considered in future C3 fraction production increase plans. Further compressor and its driving unit design features have to be incorporated in the calculation model to reliably assess the C3 fraction processing costs and provide a reliable tool for process operation optimization.
摘要在Matlab环境中,对采用热泵进行工业常规精馏以降低能量强度的丙烷-丙烯混合物裂解进行了建模。通过将所构建的模型的结果与实际C3馏分分离装置的运行数据进行比较,验证了所构建的模式。如文件所示,由于系统设计的特定特点,可以在零额外成本的情况下提高产品质量。在未来C3馏分增产计划中,必须考虑工艺能力和产品纯度限制。必须在计算模型中纳入进一步的压缩机及其驱动单元设计特征,以可靠地评估C3馏分处理成本,并为工艺操作优化提供可靠的工具。
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引用次数: 2
Electrical conductivity of low-temperature sodium-potassium cryolite melts 低温钠钾冰晶石熔体的电导率
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0004
Emília Kubiňáková, J. Híveš, V. Danielik, Andrea Červenková, Michaela Benköová
Abstract Electrical conductivity of NaF-KF-AlF3 melts with different ratios of sodium fluoride and potassium fluoride was measured using a pyrolytic boron nitride tube-type cell with constant distance of electrodes. Molar cryolite ratios MR = (n(NaF) + n(KF))/n(AlF3) varied from 1.5 to 1.2 (with a step 0.1) in the temperature range of (675—900) °C. AC-techniques with a sine wave signal with small amplitude in the high frequency range were applied. Electrolyte resistance was obtained from nonlinear regression analysis according to equivalent circuit. Concentration and temperature dependency of electrical conductivity was described and defined. Experimental data were compared with literary sources and regression equations.
摘要采用电极间距不变的热解氮化硼管式电池,测量了不同氟化钠和氟化钾比例的NaF-KF-AlF3熔体的电导率。在(675-900)°C的温度范围内,分子冰晶石比MR=(n(NaF)+n(KF))/n(AlF3)在1.5至1.2之间变化(步长为0.1)。应用了在高频范围内具有小振幅的正弦波信号的交流技术。根据等效电路,通过非线性回归分析得到电解质电阻。描述并定义了电导率的浓度和温度依赖性。实验数据与文献资料和回归方程进行了比较。
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引用次数: 2
Bis(3-methylsalicylato)bis(picolinamide)copper(II) complex — preparation, spectral properties and supposed structure 双(3-甲基水杨酸酯)双(吡啶酰胺)铜(II)配合物的制备、光谱性质和假设结构
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0014
S. Matejová, Miroslava Puchoňová, Dominika Hrindová, V. Jorík, M. Mazúr, D. Valigura
Abstract Blue methylsalicylatocopper(II) complex with picolinamide Cu(3-Mesal)2(pnia)2 has been prepared and characterized by elemental analysis and spectral methods. Based on the infrared spectra, monodentate coordination of 3-methylsalicylate anion has been assumed and the coordination variability of the anion has been shown. By determination and refinement of the unit cell from powder diffraction data, the existence of a monomeric Cu(II) complex can be anticipated. EPR spectrum of the complex is in good agreement with these results. The g-factors fulfil the relation g|| > g┴ > 2.0023, which is consistent with the dx2 – y2 ground electronic state and indicates coordination sphere of distorted tetragonal symmetry {CuN2O2O2´} for the central copper(II) ions.
摘要制备了甲基水杨酸-生育铜(II)与吡啶甲酰胺Cu(3-甲基水杨酸)2(pnia)2的蓝色配合物,并用元素分析和光谱方法对其进行了表征。基于红外光谱,假定3-甲基水杨酸根阴离子为单齿配位,并显示了阴离子的配位变异性。通过从粉末衍射数据中测定和细化晶胞,可以预期单体Cu(II)络合物的存在。配合物的EPR谱与这些结果基本一致。g因子满足关系式g||>g┴ > 2.0023,这与dx2–y2基态一致,表明中心铜(II)离子的配位球为扭曲的四方对称{CuN2O2O2´}。
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引用次数: 0
Magnetic composites based on NR and strontium ferrite 基于NR和铁氧体锶的磁性复合材料
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0010
J. Kruželák, Andrea Kvasničáková, R. Dosoudil, I. Hudeč
Abstract Two types of composites based on natural rubber (NR) and strontium ferrite were tested in this study. Composites of the first type were prepared by incorporation of strontium ferrite in the concentration range ranging from 0 to 100 phr (parts per hundred rubber) into pure NR based rubber matrix, while with those of the second type, strontium ferrite was dosed in the same concentration level into NR based rubber batch with constant amount of carbon black — 25 phr. For rubber matrices cross-linking, a standard sulfur based curing system was used. This work is focused on the effect of magnetic filler content on physico-mechanical, magnetic and thermo-physical properties of composite materials. Subsequently, the cross-link density and the structure of the formed sulfidic cross-links were examined. The results showed that the cross-link density of both types of composites increased with the increasing content of magnetic filler, while the structure of the sulfidic cross-links was almost not influenced by the amount of strontium ferrite. Tensile strength of rubber composites with pure rubber matrix was slightly improved by the incorporation of ferrite, while in case of composites based on a carbon black batch, the incorporation of magnetic filler resulted in the decrease of this characteristic. The presence of magnetic filler in both types of composites leads to a significant increase of the remanent magnetic induction.
本文对两种基于天然橡胶(NR)和锶铁氧体的复合材料进行了试验研究。第一种类型的复合材料是通过在纯NR基橡胶基体中掺入浓度范围为0-100phr(每百橡胶份数)的锶铁氧体来制备的,而对于第二种类型的材料,将相同浓度水平的锶铁素体掺入具有恒定量的炭黑-25phr的NR基橡胶批次中。对于橡胶基质交联,使用标准的硫基固化体系。研究了磁性填料含量对复合材料物理力学、磁学和热学性能的影响。随后,对交联密度和所形成的硫化交联的结构进行了检查。结果表明,两种类型的复合材料的交联密度都随着磁性填料含量的增加而增加,而硫化交联的结构几乎不受锶铁氧体含量的影响。铁氧体的加入略微提高了纯橡胶基橡胶复合材料的抗拉强度,而在炭黑基复合材料的情况下,磁性填料的加入导致了这一特性的降低。两种类型的复合材料中都存在磁性填料,导致残余磁感应显著增加。
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引用次数: 1
Use of zeolites for macronutrients removal from wastewater 沸石在去除废水中大量营养物质中的应用
IF 0.8 Q4 CHEMISTRY, MULTIDISCIPLINARY Pub Date : 2019-04-01 DOI: 10.2478/acs-2019-0021
B. Urminská, J. Derco, Ronald Zakhar, Adriana Korpicsová
Abstract Natural or synthetic zeolites have unique physical, chemical and structural properties that predetermine their use in many processes, including wastewater treatment. This study presents the results of our preliminary research in the field of nitrogen and phosphorus removal using adsorption and adsorptive ozonation with natural and modified zeolites. Iron-modified zeolite was the most efficient for the removal of ammonium nitrogen by adsorption. Phosphorus removal efficiency using adsorption was relatively low and natural zeolite was not suitable for the phosphorus removal at all. Ozone had no significant impact on the removal efficiency. Regeneration of loaded zeolites with ozone has also been studied. This method was partly efficient but it needs be further examined.
摘要天然或合成沸石具有独特的物理、化学和结构特性,这些特性决定了它们在许多工艺中的用途,包括废水处理。本研究介绍了我们在天然和改性沸石吸附和吸附臭氧化脱氮除磷领域的初步研究结果。铁改性沸石对氨氮的吸附去除效果最好。吸附除磷效率相对较低,天然沸石根本不适合除磷。臭氧对去除效率没有显著影响。还研究了负载沸石与臭氧的再生。这种方法在一定程度上是有效的,但还需要进一步研究。
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引用次数: 4
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Acta Chimica Slovaca
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