disinfection

消毒
  • 文章类型: Journal Article
    Introduction.冷等离子体经常用于消除微生物污染物的目的。在最优条件下,它可以作为治疗各种疾病的血浆药物,包括白色念珠菌引起的感染,一种机会性病原体,可以在免疫系统较弱的个体中过度生长。差距声明。迄今为止,对冷等离子体处理的白色念珠菌的分子研究较少。研究目标。该研究旨在填补在理解白色念珠菌对冷等离子体处理的分子响应方面的空白。方法论。该项目涉及测试冷等离子体发生器,以确定其对白色念珠菌浮游细胞的抗菌效果。此外,在不同的治疗持续时间(1,3和5分钟)使用RNA测序研究细胞转录组学反应。结果。结果表明,我们的冷等离子体有效地消除了白色念珠菌。冷等离子体处理导致重要途径的大幅下调,如“核苷酸代谢”,\'DNA复制和修复\',\'细胞生长\',“碳水化合物代谢”和“氨基酸代谢”。这表明白色念珠菌的细胞周期停滞以保持不利条件下的能量消耗。然而,白色念珠菌适应其GSH抗氧化系统以应对活性氧引起的氧化应激,活性氮和其他自由基。该处理可能导致细胞致病性降低,因为许多毒力因子被下调。结论。该研究证明了冷等离子体处理的白色念珠菌的主要受影响途径,为白色念珠菌对冷等离子体处理的分子响应提供有价值的见解。这些发现有助于理解冷等离子体的抗菌效率及其在微生物学领域的潜在应用。
    Introduction. Cold plasma is frequently utilized for the purpose of eliminating microbial contaminants. Under optimal conditions, it can function as plasma medicine for treating various diseases, including infections caused by Candida albicans, an opportunistic pathogen that can overgrow in individuals with weakened immune system.Gap Statement. To date, there has been less molecular study on cold plasma-treated C. albicans.Research Aim. The study aims to fill the gap in understanding the molecular response of C. albicans to cold plasma treatment.Methodology. This project involved testing a cold plasma generator to determine its antimicrobial effectiveness on C. albicans\' planktonic cells. Additionally, the cells\' transcriptomics responses were investigated using RNA sequencing at various treatment durations (1, 3 and 5 min).Results. The results show that our cold plasma effectively eliminates C. albicans. Cold plasma treatment resulted in substantial downregulation of important pathways, such as \'nucleotide metabolism\', \'DNA replication and repair\', \'cell growth\', \'carbohydrate metabolism\' and \'amino acid metabolism\'. This was an indication of cell cycle arrest of C. albicans to preserve energy consumption under unfavourable conditions. Nevertheless, C. albicans adapted its GSH antioxidant system to cope with the oxidative stress induced by reactive oxygen species, reactive nitrogen species and other free radicals. The treatment likely led to a decrease in cell pathogenicity as many virulence factors were downregulated.Conclusion. The study demonstrated the major affected pathways in cold plasma-treated C. albicans, providing valuable insights into the molecular response of C. albicans to cold plasma treatment. The findings contribute to the understanding of the antimicrobial efficiency of cold plasma and its potential applications in the field of microbiology.
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  • 文章类型: Journal Article
    “可行但不可培养”(VBNC)状态和细菌抗生素耐药性(BAR)的存在都对饮用水的安全构成了重大威胁。然而,有限的数据明确说明了细菌VBNC状态在BAR维持和繁殖中的作用.这里,两株耐药大肠埃希菌K12菌株的VBNC状态诱导和复苏,一个携带多药耐药质粒(RP4大肠杆菌),另一个具有染色体突变(RIF大肠杆菌)的特征是使它们经受不同剂量的UV/氯。结果表明,诱导,复苏,VBNCARB的相关机制表现出基于抗性决定因素的变化。与RIF大肠杆菌相比,RP4大肠杆菌表现出更高的进入VBNC状态的易感性。,大多数VBNC状态和复苏的RP4大肠杆菌保留了原始抗生素耐药性。同时,在VBNC状态下观察到rpoB基因的反向突变,并通过高剂量的UV/氯处理诱导回收的RIF大肠杆菌菌株,导致利福平抗性的丧失。根据RT-qPCR结果,赋予外排泵的ARG似乎在RP4大肠杆菌的VBNC状态形成中起着更重要的作用,并且rpoS基因的下调提高了该携带质粒的ARB进入休眠状态的速度。至于RIF大肠杆菌,VBNC状态的诱导应该由一般应激反应的组合来调节,SOS响应,严格的回应,和TA系统。最重要的是,这项研究强调,ARB可以成为VBNC状态在紫外线/氯处理,在某些情况下,他们传播ARGs的能力。重要的是,与染色体突变介导的ARB相比,VBNC和携带多重耐药质粒的复苏状态ARB都会带来更严重的健康风险.我们的研究提供了有关饮用水系统中VBNC状态与BAR传播之间关系的见解。
    The presence of \"viable but nonculturable\" (VBNC) state and bacterial antibiotic resistance (BAR) both pose significant threats to the safety of drinking water. However, limited data was available that explicitly addressed the contribution of bacterial VBNC state in the maintenance and propagation of BAR. Here, the VBNC state induction and resuscitation of two antibiotic-resistant Escherichia coli K12 strains, one carrying multidrug-resistant plasmid (RP4 E. coli) and the other with chromosomal mutation (RIF E. coli) were characterized by subjecting them to different doses of UV/chlorine. The results illustrated that the induction, resuscitation, and associated mechanisms of VBNC ARB exhibit variations based on resistance determinants. RP4 E. coli exhibited a higher susceptibility to enter VBNC state compared to the RIF E. coli., and most VBNC state and resuscitated RP4 E. coli retained original antibiotic resistance. While, reverse mutation in the rpoB gene was observed in VBNC state and recovered RIF E. coli strains induced by high doses of UV/chlorine treatment, leading to the loss of rifampicin resistance. According to RT-qPCR results, ARGs conferring efflux pumps appeared to play a more significant role in the VBNC state formation of RP4 E. coli and the down-regulation of rpoS gene enhanced the speed at which this plasmid-carrying ARB entered into the dormant state. As to RIF E. coli, the induction of VBNC state was supposed to be regulated by the combination of general stress response, SOS response, stringent response, and TA system. Above all, this study highlights that ARB could become VBNC state during UV/chlorine treatments and retain, in some cases, their ability to spread ARGs. Importantly, compared with chromosomal mutation-mediated ARB, both VBNC and resuscitated state ARB that carries multidrug-resistant plasmids poses more serious health risks. Our study provides insights into the relationship between the VBNC state and the propagation of BAR in drinking water systems.
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  • 文章类型: Journal Article
    Objective: To evaluate the disinfection effect of high-energy pulse ultraviolet disinfection equipment in medical institution settings. Methods: The disinfection effect was evaluated through field tests and laboratory tests. Among them, 135 high-frequency contact points were selected from nine departments in the field test. Samples were collected before and after disinfection, and the disinfection effects of 75% alcohol wipes wiping disinfection, high-energy pulse ultraviolet disinfection robot disinfection and high-energy pulse ultraviolet handheld disinfection instrument were compared. In the laboratory test, 30 infected areas of the simulated test table were exposed to vertical ultraviolet irradiation and the bacterial-killing rate before and after disinfection was calculated. Results: In the field test, the bacteria-killing rates of 75% alcohol wipes, high-energy pulse ultraviolet disinfection robot and high-energy pulse ultraviolet handheld disinfection instrument were 94.99%, 91.53% and 95.94%, respectively, and the difference was statistically significant. The disinfection effect of the high-energy pulse ultraviolet handheld disinfection instrument was better than that of the high-energy pulse ultraviolet disinfection robot (P values <0.05). In the laboratory test, the killing log value of Staphylococcus aureus and Escherichia coli on the carrier were both greater than 3.00. In the simulated field test, the killing log value of Staphylococcus aureus on the surface samples were 4.99. Conclusion: Both the high-energy pulse ultraviolet handheld disinfection instrument and the high-energy pulse ultraviolet disinfection robot have good disinfection effects, which are similar to the disinfection effects of conventional 75% alcohol wipes.
    目的: 评价医疗机构场景下高能脉冲紫外线消毒设备消毒效果。 方法: 分别通过现场试验和实验室试验进行消毒效果评价。其中,现场试验选择9个科室135个高频接触点位,消毒前后采样,比较75%酒精湿巾擦拭消毒、高能脉冲紫外消毒机器人消毒和高能脉冲紫外手持消毒仪消毒效果;实验室试验将模拟试验桌面的30个染菌区块置于紫外线垂直照射下,计算消毒前后细菌杀灭率。 结果: 现场试验中75%酒精湿巾擦拭、高能脉冲紫外消毒机器人和高能脉冲紫外手持消毒仪细菌杀灭率分别为94.99%、91.53%和95.94%,差异有统计学意义,其中高能脉冲紫外手持消毒仪的消毒效果好于高能脉冲紫外消毒机器人(P<0.05)。实验室试验中高能脉冲紫外手持消毒仪对染菌载体上金黄色葡萄球菌和大肠杆菌的杀灭对数值均>3.00,模拟现场试验中高能脉冲紫外手持消毒仪对物体表面样本上金黄色葡萄球菌的杀灭对数值为4.99。 结论: 高能脉冲紫外手持消毒仪和高能脉冲紫外消毒机器人消毒效果均较好,与常规75%酒精湿巾擦拭消毒效果相近。.
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  • 文章类型: English Abstract
    超声诊断和治疗易于执行,花费的时间很少。由于其非侵入性,它在临床实践中被广泛使用,实时,和动态特性。在超声诊断和治疗过程中,探针可能会与皮肤接触,粘膜,甚至身体的无菌部分。然而,使用后难以对探头进行有效的实时消毒,并且经常重复使用,导致探针携带多种致病菌的可能性。目前,国内外探针的加工方法主要包括探针清洗、探头消毒,和物理隔离(使用探头盖或护套)。然而,每种方法都有其局限性,不能完全防止超声诊断和治疗引起的探头污染和感染。例如,当避孕套被用作探针鞘时,安全套破损率相对较高。保鲜膜或冷冻袋的切割和固定涉及复杂的程序并且难以执行。一次性塑料手套容易脱落并造成污染,因此不符合无菌原则。此外,一次性塑料手套的成像效果差。因此,迫切需要探索新材料,以制造不仅可以紧紧包裹超声探头的探头盖,还有助于实现有效保护和快速重用。基于物理障碍的概念,在这项研究中,我们开发了一种热密封系统,用于快速重复使用超声探头。该系统使用热封装置使保护膜收缩,使其紧贴超声探头表面,允许快速重复使用探针,同时降低医院感染的风险。目的设计超声探头快速复用热封系统,并验证其在超声探头快速复用中的应用效果。
    1)通过整合医学和工程方法,设计和测试了用于快速重复使用超声探头的热封系统。该系统包括保护膜(多层共挤出聚烯烃热收缩膜)和热密封装置,其中包括加热丝组件,鼓风机,一个光电开关,温度传感器,控制和驱动电路板,等。根据热收缩原理,快速加热配有热收缩膜的超声探头,膜将紧密包裹在放置在热封机顶部的超声探头周围。超声探头在热收缩过程完成后准备使用。在探头表面安装温度传感器,测试系统的隔热性能。该系统的操作程序如下:将覆盖有保护膜的超声探头放置在保护通风口上方的一定空间中,由光电开关检测;加热装置在设定温度值下,用恒定的热风流量对热收缩膜进行加热。然后,探针被旋转,使得热收缩膜将快速地缠绕在超声探针周围。热收缩完成后,探头可以直接使用。2)采用便利抽样方法,麻醉和围手术期医学部的90名患者,以西安交通大学第一附属医院为研究对象。所有患者均在超声引导下进行动脉穿刺。受试者分为3组,每组30名患者。使用临床上常用的三种方法对三组探针进行处理,并在使用前在穿刺部位周围进行水溶性荧光标记。在实验组中,探头用热封系统处理。执行用于快速重复使用超声探头的热密封系统的标准操作程序以覆盖超声探头并形成物理屏障以防止探头污染。有两个对照组。对照组1使用含双链季铵盐的消毒湿巾反复擦拭探头表面10-15次,然后探针一旦干涸就可以使用了。在对照组2中,使用一次性保护套覆盖探针的前端,并用螺纹将护套的手柄端绑住。使用前后探针表面的水溶性荧光标记(反映探针表面的菌落残基)和重复使用时间(即,从第一次使用结束到第二次使用开始的时间)在实验组和两个对照组之间进行。
    1)超声探头内部的温度低于40℃,用于快速重复使用的热封系统不影响超声探头的性能。2)热封系统组中的重复使用时间,表示为(中位数[P25,P75]),是(8.00[7.00,10.00])s,显著低于消毒擦拭组(95.50[8.00,214.00])s和保护套组(25.00[8.00,51.00])s,差异有统计学意义(P<0.05)。使用后,在热封系统组或保护护套组中的探针上均未发现荧光残留物。热封系统组的荧光残留量明显低于消毒湿巾组,差异有统计学意义(χ2=45.882,P<0.05)。
    本研究中设计和开发的热收缩膜可以根据设备的尺寸进行切割和修剪。当薄膜被加热时,它收缩并紧紧地包裹在设备上,形成坚固的保护层。随着超声波探头快速重复使用的热封系统,实现了热收缩膜与加热装置的半自动连接,减少了耗时和复杂的手工操作。此外,缩短了平均重用时间,系统易于使用,这有助于提高超声探头的重复使用和操作效率。热封系统减少了探针表面上的菌落残留,并在探针上形成有效的物理屏障。在研究中没有探针被损坏。超声探头快速重复使用的热封系统可作为超声探头加工的一种新方法。
    UNASSIGNED: Ultrasound diagnosis and treatment is easy to perform and takes little time. It is widely used in clinical practice thanks to its non-invasive, real-time, and dynamic characteristics. In the process of ultrasound diagnosis and treatment, the probe may come into contact with the skin, the mucous membranes, and even the sterile parts of the body. However, it is difficult to achieve effective real-time disinfection of the probes after use and the probes are often reused, leading to the possibility of the probes carrying multiple pathogenic bacteria. At present, the processing methods for probes at home and abroad mainly include probe cleaning, probe disinfection, and physical isolation (using probe covers or sheaths). Yet, each approach has its limitations and cannot completely prevent probe contamination and infections caused by ultrasound diagnosis and treatment. For example, when condoms are used as the probe sheath, the rate of condom breakage is relatively high. The cutting and fixing of cling film or freezer bags involves complicated procedures and is difficult to perform. Disposable plastic gloves are prone to falling off and causing contamination and are hence not in compliance with the principles of sterility. Furthermore, the imaging effect of disposable plastic gloves is poor. Therefore, there is an urgent need to explore new materials to make probe covers that can not only wrap tightly around the ultrasound probe, but also help achieve effective protection and rapid reuse. Based on the concept of physical barriers, we developed in this study a heat sealing system for the rapid reuse of ultrasound probes. The system uses a heat sealing device to shrink the protective film so that it wraps tightly against the surface of the ultrasound probe, allowing for the rapid reuse of the probe while reducing the risk of nosocomial infections. The purpose of this study is to design a heat sealing system for the rapid reuse of ultrasound probes and to verify its application effect on the rapid reuse of ultrasound probes.
    UNASSIGNED: 1) The heat sealing system for the rapid reuse of ultrasound probes was designed and tested by integrating medical and engineering methods. The system included a protective film (a multilayer co-extruded polyolefin thermal shrinkable film) and a heat sealing device, which included heating wire components, a blower, a photoelectric switch, temperature sensors, a control and drive circuit board, etc. According to the principle of thermal shrinkage, the ultrasound probe equipped with thermal shrinkable film was rapidly heated and the film would wrap closely around the ultrasound probe placed on the top of the heat sealing machine. The ultrasound probe was ready for use after the thermal shrinkage process finished. Temperature sensors were installed on the surface of the probe to test the thermal insulation performance of the system. The operation procedures of the system are as follows: placing the ultrasound probe covered with the protective film in a certain space above the protective air vent, which is detected by the photoelectric switch; the heating device heats the thermal shrinkable film with a constant flow of hot air at a set temperature value. Then, the probe is rotated so that the thermal shrinkable film will quickly wrap around the ultrasound probe. After the heat shrinking is completed, the probe can be used directly. 2) Using the convenience sampling method, 90 patients from the Department of Anesthesiology and Perioperative Medicine, the First Affiliated Hospital of Xi\'an Jiaotong University were included as the research subjects. All patients were going to undergo arterial puncture under ultrasound guidance. The subjects were divided into 3 groups, with 30 patients in each group. Three measures commonly applied in clinical practice were used to process the probes in the three groups and water-soluble fluorescent labeling was applied around the puncture site before use. In the experimental group, the probes were processed with the heat sealing system. The standard operating procedures of the heat sealing system for rapid reuse of ultrasonic probes were performed to cover the ultrasonic probe and form a physical barrier to prevent probe contamination. There were two control groups. In control group 1, disinfection wipes containing double-chain quaternary ammonium salt were used to repeatedly wipe the surface of the probe for 10-15 times, and then the probe was ready for use once it dried up. In the control group 2, a disposable protective sheath was used to cover the front end of the probe and the handle end of the sheath was tied up with threads. Comparison of the water-soluble fluorescent labeling on the surface of the probe (which reflected the colony residues on the surface of the probe) before and after use and the reuse time (i.e., the lapse of time from the end of the first use to the beginning of the second use) were made between the experimental group and the two control groups.
    UNASSIGNED: 1) The temperature inside the ultrasound probe was below 40 ℃ and the heat sealing system for rapid reuse did not affect the performance of the ultrasound probe. 2) The reuse time in the heat sealing system group, as represented by (median [P25, P75]), was (8.00 [7.00, 10.00]) s, which was significantly lower than those of the disinfection wipe group at (95.50 [8.00, 214.00]) s and the protective sleeve group at (25.00 [8.00, 51.00]) s, with the differences being statistically significant (P<0.05). No fluorescence residue was found on the probe in either the heat sealing system group or the protective sheath group after use. The fluorescence residue in the heat sealing system group was significantly lower than that in the disinfection wipes group, showing statistically significant differences (χ 2=45.882, P<0.05).
    UNASSIGNED: The thermal shrinkable film designed and developed in this study can be cut and trimmed according to the size of the equipment. When the film is heated, it shrinks and wraps tightly around the equipment, forming a sturdy protective layer. With the heat sealing system for rapid reuse of ultrasonic probes, we have realized the semi-automatic connection between the thermal shrinkable film and the heating device, reducing the amount of time-consuming and complicated manual operation. Furthermore, the average reuse time is shortened and the system is easy to use, which contributes to improvements in the reuse and operation efficiency of ultrasound probes. The heat sealing system reduces colony residues on the surface of the probe and forms an effective physical barrier on the probe. No probes were damaged in the study. The heat sealing system for rapid reuse of ultrasonic probes can be used as a new method to process the ultrasonic probes.
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  • 文章类型: Journal Article
    目的:消毒剂的消毒效果因具体情况而异。本研究旨在探讨商业过氧化氢的消毒效率,二氧化氯,和氯消毒剂在真实的现场表面,并为精确消毒提供数据。
    方法:采用模拟现场消毒和现场消毒方法定量评价过氧化氢的消毒效率,二氧化氯,和二氯异氰尿酸钠.log10生物指标的减少,大肠杆菌(ATCC8099)和金黄色葡萄球菌(ATCC6538),已计算。接下来,确定了食品生产和加工车间和生物安全实验室表面上天然细菌的减少。
    结果:评估的3种商业消毒剂对大肠杆菌和金黄色葡萄球菌有效,减少超过3.00log10菌落形成单位/毫升测试15分钟与3.5%过氧化氢的暴露时间,100毫克/升二氧化氯,和250mg/L二氯异氰尿酸钠。使用10.5%的过氧化氢,暴露时间为30分钟,食品生产和加工车间的自然负荷降低了90%以上。在生物安全2级实验室中,通过在60分钟的暴露时间下500mg/L的二氧化氯和在60分钟的暴露时间下450mg/L的二氯异氰尿酸钠实现相同的消毒水平。
    结论:本研究为食品工业和生物安全实验室的表面精确消毒提供了参考。
    OBJECTIVE: The disinfection efficiency of disinfectants differs in specific conditions. This study aimed to investigate the disinfection efficiency of commercial hydrogen peroxide, chlorine dioxide, and chlorine disinfectant on real field surfaces and provide data for precise disinfection.
    METHODS: Simulated field disinfection and field disinfection methods were conducted to quantitatively evaluate the disinfection efficiency of hydrogen peroxide, chlorine dioxide, and sodium dichloroisocyanurate. The log10 reduction of biological indicators, Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538), was calculated. Next, the reduction in natural bacteria on the surfaces of a food production and processing workshop and a biosafety laboratory was determined.
    RESULTS: The 3 commercial disinfectants evaluated were effective against E coli and S aureus, with a reduction of more than 3.00 log10 colony-forming units/mL tested for an exposure time of 15 minutes with 3.5% hydrogen peroxide, 100 mg/L chlorine dioxide, and 250 mg/L sodium dichloroisocyanurate. The natural load in the food production and processing workshop decreased by more than 90% using 10.5% hydrogen peroxide with an exposure time of 30 minutes. The same disinfection level in the biosafety level 2 laboratory was achieved by 500 mg/L chlorine dioxide at an exposure time of 60 minutes and 450 mg/L sodium dichloroisocyanurate at 60 minutes.
    CONCLUSIONS: This study provides a reference for precise disinfection of surfaces in the food industry and biosafety laboratories.
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  • 文章类型: Journal Article
    水传播病原体总是对公众健康构成相当大的威胁。群体感应(QS)系统有助于协调细菌的生长和代谢。然而,细菌通过群体感应对各种消毒技术的反应和调节机制尚不清楚。这项研究研究了氯化和臭氧化对铜绿假单胞菌QS信号缺乏突变体的生物膜和浮游细胞的灭活作用。细胞计数和活力评估表明,氯和臭氧的联合消毒对于在暴露后10分钟内灭活浮游铜绿假单胞菌最有效。此外,微流控芯片培养表明,喹诺酮类药物信号的分泌增强了生物膜的消毒抗性。消毒暴露显着改变了野生型菌株和QS信号缺乏突变体的基因表达。此外,QS系统触发了多层基因表达程序,作为对消毒剂暴露的响应性保护,包括氧化应激,核糖体合成,和细菌的营养吸收。这些见解扩大了我们对细菌QS对消毒的反应的理解,有希望的潜在策略,以实现有效的消毒过程。
    Waterborne pathogens invariably present considerable threats to public health. The quorum sensing (QS) system is instrumental in coordinating bacterial growth and metabolisms. However, the responses and regulatory mechanisms of bacteria to various disinfection technologies through quorum sensing are still unclear. This study examines the inactivation effect of chlorination and ozonation on biofilms and planktonic cells of QS signaling-deficient mutants of Pseudomonas aeruginosa. Cell counting and viability assessment revealed that the combined disinfection of chlorine and ozone was the most effective for inactivating planktonic P. aeruginosa within 10 min of exposure. Additionally, microfluidic chip culture demonstrated that the secretion of quinolone signals escalated biofilms\' disinfection resistance. Disinfection exposure significantly altered the gene expression of wild-type strains and QS signaling-deficient mutants. Moreover, the QS system triggered multilayered gene expression programs as a responsive protection to disinfectant exposure, including oxidative stress, ribosome synthesis, and the nutrient absorption of bacteria. These insights broaden our understanding of bacterial QS in response to disinfection, promising potential strategies toward efficient disinfection processes.
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  • 文章类型: Journal Article
    联合下水道溢流(CSO)将微生物污染物引入接收水体,从而对公众健康构成风险。本研究系统地研究了选择大肠杆菌(E。大肠杆菌)作为目标微生物污染物。与UV、PAA,和UV/H2O2工艺。增加PAA用量大大提高了消毒效率,而浊度和有机物阻碍了失活性能。单线态氧(1O2),羟基(·OH)和有机自由基(RO·)有助于大肠杆菌的失活,·OH和RO·起着突出的作用。细胞内活性氧的变化,丙二醛,酶活性,大肠杆菌细胞的DNA含量和生化成分表明,UV/PAA主要引起细胞内分子的氧化损伤,而不是细胞膜脂质的损伤。因此有效地限制了大肠杆菌的再生长。此外,UV/PAA工艺在消毒实际原始公民社会组织方面表现突出,在反应4分钟后实现总细菌的2.90-log失活。这些结果突出了UV/PAA工艺在CSO消毒中的实际适用性和有效性。
    Combined sewer overflows (CSOs) introduce microbial contaminants into the receiving water bodies, thereby posing risks to public health. This study systematically investigated the disinfection performance and mechanisms of the combined process of ultraviolet and peracetic acid (UV/PAA) in CSOs with selecting Escherichia coli (E. coli) as a target microbial contaminant. The UV/PAA process exhibited superior performance in inactivating E. coli in simulated CSOs compared with UV, PAA, and UV/H2O2 processes. Increasing the PAA dosage greatly enhanced the disinfection efficiency, while turbidity and organic matter hindered the inactivation performance. Singlet oxygen (1O2), hydroxyl (•OH) and organic radicals (RO•) contributed to the inactivation of E. coli, with •OH and RO• playing the prominent role. Variations of intracellular reactive oxygen species, malondialdehyde, enzymes activities, DNA contents and biochemical compositions of E. coli cells suggested that UV/PAA primarily caused oxidative damage to intracellular molecules rather than the damage to the lipids of the cell membrane, therefore effectively limited the regrowth of E. coli. Additionally, the UV/PAA process displayed an outstanding performance in disinfecting actual raw CSOs, achieving a 2.90-log inactivation of total bacteria after reaction for 4 min. These results highlighted the practical applicability and effectiveness of the UV/PAA process in the disinfection of CSOs.
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  • 文章类型: Journal Article
    鲜切农产品通常是在标准化的消毒过程下生产的,在即食阶段不可用。目前,化学消毒剂用于洗涤,但其消毒功效有限。在这项研究中,UV-C(1.03kJ/m2)与通常认为安全的有机酸(GRAS)结合使用,包括柠檬酸,苹果酸,乙酸,和乳酸(LA),洗涤被大肠杆菌O157:H7和鼠伤寒沙门氏菌污染的生菜和樱桃番茄。结果表明,在单一治疗方法中,LA是最有效的治疗方法,病原体减少和交叉污染发生率为2.0-2.3logCFU/g和28-35%,分别。与UV-C结合后,4种GRAS酸的消毒效果和防交叉污染能力明显提高。在联合治疗中,通过LA-UV实现了最高的病原体减少(2.5-2.7logCFU/g)和最低的交叉污染发生率(11-15%).抗坏血酸的分析,叶绿素,番茄红素,抗氧化能力,和ΔE表明,单一或组合处理都不会对质量性能产生负面影响。这些结果为即食阶段的新鲜农产品安全性改善提供了潜在的障碍技术。
    Fresh-cut produce is usually produced under standardized disinfection processes, which are unavailable at the ready-to-eat stage. Currently, chemical sanitizers are used for washing, but their disinfection efficacy is limited. In this study, UV-C (1.03 kJ/m2) was combined with organic acids that are generally recognized as safe (GRAS), including citric, malic, acetic, and lactic acids (LAs), to wash lettuce and cherry tomatoes that are contaminated with Escherichia coli O157:H7 and Salmonella Typhimurium. The results showed that LA was the most effective treatment among the single treatments, with a pathogen reduction and cross-contamination incidence of 2.0-2.3 log CFU/g and 28-35%, respectively. After combining with UV-C, the disinfection efficacy and cross-contamination prevention capacity of the four GRAS acids significantly improved. Among the combination treatments, the highest pathogen reduction (2.5-2.7 log CFU/g) and the lowest cross-contamination incidence (11-15%) were achieved by LA-UV. The analyses of ascorbic acid, chlorophyll, lycopene, antioxidant capacity, and ΔE indicated that neither the single nor combination treatments negatively affected the quality properties. These results provide a potential hurdle technology for fresh produce safety improvement at the ready-to-eat stage.
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  • 文章类型: Journal Article
    尽管传统的纳滤(NF)膜在水处理中得到了广泛的应用,它面临着对新兴污染物选择性不足的挑战,低渗透性和不可持续的污垢控制。在这里,一种新型的电活性金属-有机框架/碳纳米管膜是通过容易和绿色纳米气泡介导的非溶剂诱导相分离(NIPS)策略构建的超快抗生素去除。它的渗透性高3倍至100倍(101.3-105.7L·h-1·m-2·bar-1),而不损害对常见抗生素(四环素,诺氟沙星,磺胺甲恶唑,磺胺二甲嘧啶)比大多数商业和最先进的NF膜。分离机制是由于具有三维互连网络的松散选择层和具有独特的孔筛分和电荷性质的UiO-66/CNT的协同作用。对于抗生素和重金属复合污染的修复,它还具有优异的抗生素选择性,具有较高的NaCl/四环素分离因子194和CuCl2/四环素分离因子316。同时,它具有有效的防污,抗菌和电动自清洁能力,这使得可持续的污染控制和消毒过程短,低能源和化学消耗。此外,UiO-66/CNTs膜在废水回收中的潜在应用通过稳定的抗生素排斥来证明,有效的通量恢复和长期稳定性超过260小时。这项研究将提供有用的见解,通过先进的NF膜从水中去除新出现的污染物。
    Although conventional nanofiltration (NF) membrane is widely applied in water treatment, it faces the challenges of insufficient selectivity toward emerging contaminants, low permeability and non-sustainable fouling control. Herein, a novel electroactive metal-organic frameworks/carbon nanotubes membrane was constructed by facile and green nanobubbles-mediated non-solvent-induced phase separation (NIPS) strategy for ultrafast antibiotics removal. It presented 3-fold to 100-fold higher permeability (101.3-105.7 L·h-1·m-2·bar-1) without compromising rejection (71.8 %-99.3 %) of common antibiotics (tetracycline, norfloxacin, sulfamethoxazole, sulfamethazine) than most commercial and state-of-the-art NF membranes. The separation mechanism was due to the synergy of loose selective layer with three-dimensional interconnected networks and UiO-66/CNTs with unique pore sieving and charge property. It also presented excellent antibiotics selectivity with high NaCl/tetracycline separation factor of 194 and CuCl2/tetracycline separation factor of 316 for remediation of antibiotics and heavy metal combined pollution. Meanwhile, it possessed efficient anti-fouling, antibacterial and electro-driven self-cleaning ability, which enabled sustainable fouling control and disinfection with short process, low energy and chemical consumption. Furthermore, potential application of UiO-66/CNTs membrane in wastewater reclamation was demonstrated by stable antibiotics rejection, efficient flux recovery and long-term stability over 260 h. This study would provide useful insights into removal of emerging contaminants from water by advanced NF membrane.
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  • 文章类型: Journal Article
    原位过氧化氢(H2O2)应用于消毒和氧化过程。从水和氧气中光产生H2O2,避免依赖有机化学品,并可能实现比电化学方法更小尺寸或更低成本的反应器。在超纯水中,我们之前展示了一种新型的双光纤系统,该系统将发光二极管(LED)与金属有机框架(MOF)催化剂涂覆的光纤(POF-MIL-101(Fe))和基于O2的中空膜纤维耦合,并实现了显着的H2O2产率,308±1.4mMh-1催化剂-g-1。为了在任何地方生产H2O2,我们试图了解常见水质参数的影响。H2O2的产生不受添加钠的影响,钾,氢氧化物,硫酸根或硝酸根离子。在宽pH范围(4-10)内具有一致的性能,即使在pH10下也保持232±3.5mMh-1催化剂-g-1的高生产率,这通常不利于H2O2的光生产。氯离子产生次氯酸,消耗原位产生的H2O2。铁基MOF催化剂上的磷酸盐吸附阻止了H2O2的产生。由于原位甲酸,无机碳物质抑制了H2O2的产生。使用大气水获得了令人鼓舞的结果(即,冷凝水),速率达到288±6.1mMh-1催化剂-g-1,与超纯水相当。这强调了大气水是一种可变的替代品,几乎所有建筑空调系统都有,或者可以克服地理限制,特别是在获得纯净水资源具有挑战性的地区,提供具有成本效益的解决方案。使用大气水的双纤维反应器可随时随地高效生产H2O2。
    In-situ hydrogen peroxide (H2O2) finds applications in disinfection and oxidation processes. Photoproduction of H2O2 from water and oxygen, avoids reliance upon organic chemicals, and potentially enables smaller-sized or lower-cost reactors than electrochemical methods. In ultrapure water, we previously demonstrated a novel dual-fiber system coupling a light emitting diode (LED) with a metal-organic framework (MOF) catalyst-coated optical fiber (POF-MIL-101(Fe)) and O2-based hollow-membrane fibers and achieved a remarkable H2O2 yield, 308 ± 1.4 mM h-1 catalyst-g-1. To enable H2O2 production anywhere we sought to understand the impacts of common water quality parameters. The production of H2O2 was not affected by added sodium, potassium, hydroxide, sulfate or nitrate ions. There was consistent performance over a wide pH range (4-10), maintaining a high production rate of 232 ± 3.5 mM h-1 catalyst-g-1 even at pH 10, a condition typically unfavorable for H2O2 photoproduction. Chloride ions produced hypochlorous acid, consuming in-situ produced H2O2. Phosphate adsorption on the iron-based MOF catalysts blocked H2O2 production. Inorganic carbon species inhibited H2O2 production due to in-situ formic acid. Encouraging results were obtained using atmospheric water (i.e., condensate), with rates reaching 288 ± 6.1 mM h-1 catalyst-g-1, comparable to ultrapure water. This underscores atmospheric water as a variable alternative, available in nearly all building air conditioning systems or could overcome geographical constraints, particularly in regions where obtaining pure water resources is challenging, offering a cost-effective solution. The dual-fiber reactor using atmospheric water enables high-efficiency H2O2 production anytime and anywhere.
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