scholarly journals Detecting and Quantifying Polyhaloaromatic Environmental Pollutants by Chemiluminescence-Based Analytical Method

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3365
Author(s):  
Ben-Zhan Zhu ◽  
Miao Tang ◽  
Chun-Hua Huang ◽  
Li Mao
Keyword(s):  
Analytical Method ◽  
Degradation Kinetics ◽  
Environmental Pollutants ◽  
Environmental Implications ◽  
Future Studies ◽  
System A ◽  
Quinoid Structure ◽  
Fenton System ◽  
Generating System ◽  
H2o2 System

Polyhaloaromatic compounds (XAr) are ubiquitous and recalcitrant in the environment. They are potentially carcinogenic to organisms and may induce serious risks to the ecosystem, raising increasing public concern. Therefore, it is important to detect and quantify these ubiquitous XAr in the environment, and to monitor their degradation kinetics during the treatment of these recalcitrant pollutants. We have previously found that unprecedented intrinsic chemiluminescence (CL) can be produced by a haloquinones/H2O2 system, a newly-found ●OH-generating system different from the classic Fenton system. Recently, we found that the degradation of priority pollutant pentachlorophenol by the classic Fe(II)-Fenton system could produce intrinsic CL, which was mainly dependent on the generation of chloroquinone intermediates. Analogous effects were observed for all nineteen chlorophenols, other halophenols and several classes of XAr, and a novel, rapid and sensitive CL-based analytical method was developed to detect these XAr and monitor their degradation kinetics. Interestingly, for those XAr with halohydroxyl quinoid structure, a Co(II)-mediated Fenton-like system could induce a stronger CL emission and higher degradation, probably due to site-specific generation of highly-effective ●OH. These findings may have broad chemical and environmental implications for future studies, which would be helpful for developing new analytical methods and technologies to investigate those ubiquitous XAr.

scholarly journals Bactericidal activity of a superoxide anion-generating system. A model for the polymorphonuclear leukocyte.

1979 ◽  
Vol 149 (1) ◽  
pp. 27-39 ◽  
Author(s):  
H Rosen ◽  
S J Klebanoff
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Bactericidal Activity ◽  
Parent Strain ◽  
Carotenoid Pigments ◽  
Bacterial Killing ◽  
Oxidase System ◽  
System A ◽  
Presence And Absence ◽  
Generating System

The acetaldehyde-xanthine oxidase system in the presence and absence of myeloperoxidase (MPO) and chloride has been employed as a model of the oxygen-dependent antimicrobial systems of the PMN. The unsupplemented xanthine oxidase system was bactericidal at relatively high acetaldehyde concentrations. The bactericidal activity was inhibited by superoxide dismutase (SOD), catalase, the hydroxyl radical (OH.) scavengers, mannitol and benzoate, the singlet oxygen (1O2) quenchers, azide, histidine, and 1,4-diazabicyclo[2,2,2]octane (DABCO) and by the purines, xanthine, hypoxanthine, and uric acid. The latter effect may account for the relatively weak bactericidal activity of the xanthine oxidase system when purines are employed as substrate. A white, carotenoid-negative mutant strain of Sarcina lutea was more susceptible to the acetaldehyde-xanthine oxidase system than was the yellow, carotenoid-positive parent strain. Carotenoid pigments are potent 1O2 quenchers. The xanthine oxidase system catalyzes the conversion of 2,5-diphenylfuran to cis-dibenzoylethylene, a reaction which can occur by a 1O2 mechanism. This conversion is inhibited by SOD, catalase, azide, histidine, DABCO, xanthine, hypoxanthine, and uric acid but is only slightly inhibited by mannitol and benzoate. The addition of MPO and chloride to the acetaldehyde-xanthine oxidase system greatly increases bactericidal activity; the minimal effective acetaldehyde concentration is decreased 100-fold and the rate and extent of bacterial killing is increased. The bactericidal activity of the MPO-supplemented system is inhibited by catalase, benzoate, azide, DABCO, and histidine but not by SOD or mannitol. Thus, the acetaldehyde-xanthine oxidase system which like phagocytosing PMNs generates superoxide (O.2-) and hydrogen peroxide, is bactericidal both in the presence and absence of MPO and chloride. The MPO-supplemented system is considerably more potent; however, when MPO is absent, bactericidal activity is observed which may be mediated by the interaction of H2O2 and O.2- to form OH. and 1O2.

scholarly journals Yet Another Intelligent Code-Generating System: A Flexible and Low-Cost Solution

2018 ◽  
Vol 33 (5) ◽  
pp. 940-965 ◽  
Author(s):  
João Fabrício Filho ◽  
Luis Gustavo Araujo Rodriguez ◽  
Anderson Faustino da Silva
Keyword(s):  
Low Cost ◽  
System A ◽  
Generating System

scholarly journals Photonic crystals obtained by soap-free emulsion terpolymerization

2014 ◽  
Vol 12 (1) ◽  
pp. 126-130
Author(s):  
Edina Rusen ◽  
Aurel Diacon ◽  
Alexandra Mocanu
Keyword(s):  
Homogeneous Nucleation ◽  
Water Solubility ◽  
Gel Permeation Chromatography ◽  
Nucleation Mechanism ◽  
Hydroxyethyl Methacrylate ◽  
System A ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Nucleation Mechanisms ◽  
Generating System

AbstractThis paper presents the use of soap-free emulsion terpolymerization to obtainphotonic crystals (PCs). Monodisperse latexes resulted from the polymerization of styrene (ST) with 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) at different compositions defined as system A, B and C respectively. The water solubility of the macroradicals determined different nucleation mechanisms in all three cases. The micellar nucleation mechanism was more predominant for generating system A, whereas the homogeneous nucleation was specific for system C. For system B, both nucleation mechanisms werepossible with the same probability. The latexes and the resulted PCs were characterized by optical microscopy (OM), dynamic light scattering (DLS), gel permeation chromatography (GPC) and UV-VIS spectroscopy.

The orexin system: a potential player in the pathophysiology of absence epilepsy?

2021 ◽  
Vol 19 ◽  
Author(s):  
Roberta Celli ◽  
Gilles Van Luijtelaar
Keyword(s):  
Somatosensory Cortex ◽  
Molecular Mechanisms ◽  
Recent Literature ◽  
Absence Epilepsy ◽  
Experimental Animals ◽  
Future Studies ◽  
Protein Levels ◽  
System A ◽  
Cortical Circuit

Background : Absence epilepsy is characterized by the presence of spike-and-wave discharges (SWDs) at the EEG generated within the cortico-thalamo-cortical circuit. The molecular mechanisms involved in the pathophysiology of absence epilepsy are only partially known. WAG/Rij rats older than 2-3 months develop spontaneous SWDs, and they are sensitive to anti-absence medications. Hence, WAG/Rij rats are extensively used as a model for absence epilepsy with predictive validity. Objective : To examine the possibility that the orexin system, which supports the wake status in experimental animals and humans, plays a role in the pathophysiology of absence seizures. Methods : The perspective grounds its method on recent literature along with measurements of orexin receptor type-1 (OX1) protein levels in the thalamus and somatosensory cortex of WAG/Rij rats and non-epileptic Wistar control rats at two ages (25 days and 6-7 months). OX1 protein levels were measured by immunoblotting. Results : The analysis of the current literature suggests that the orexin system might be involved in the pathophysiology of absence epilepsy and might be targeted by therapeutic intervention. Experimental data are in line with this hypothesis showing that OX1 protein levels were reduced in the thalamus and somatosensory cortex of symptomatic WAG/Rij rats (6-7 months of age) with respect to non-epileptic controls, whereas these differences were not seen in pre-symptomatic, 25 days-old WAG/Rij rats. Conclusions : This might pave the way to future studies on the involvement of the orexinergic system in the pathophysiology of SWDs associated with absence epilepsy and its comorbidities.

Influence of Plasma Torch Nozzle Design on Plasma Arc Analyzed with Finite Element Method

2015 ◽  
Vol 1095 ◽  
pp. 751-755
Author(s):  
Hai Yan Wang ◽  
Yi Jiang ◽  
Yuan Peng Xia ◽  
Yun Li Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plasma Torch ◽  
Plasma Arc ◽  
Direction Parallel ◽  
System A ◽  
Welding Torch ◽  
Large Pressure ◽  
Generating System ◽  
Element Method

Plasma torch is one of the most important parts for plasma arc generating system. A design of orifices in a nozzle would decide the properties of plasma arc. However, mechanisms of orifice to plasma arc are seldom discussed. In this paper, the plasma arc with two assistant orifices were analyzed by finite element method. It was concluded that the plasma arc would be further compressed in the direction parallel to two assistant orifices, but expand perpendicular to assistant orifices. Through the constriction of two assistant orifices, the shape of the plasma arc would be elliptical other than circular of the oridinary plasma arc. The torch design with two assistant orifices could be available to many fields such as plasma arc welding, especially to a welding torch with a large pressure chamber.

scholarly journals Comparison of the degradation of molecular and ionic ibuprofen in a UV/H2O2 system

2018 ◽  
Vol 77 (9) ◽  
pp. 2174-2183 ◽  
Author(s):  
Rongkui Su ◽  
Liyuan Chai ◽  
Chongjian Tang ◽  
Bo Li ◽  
Zhihui Yang
Keyword(s):  
Quantum Yield ◽  
Rate Constant ◽  
Degradation Rate ◽  
Molecular Form ◽  
Degradation Kinetics ◽  
Dominant Role ◽  
Radical Scavenging ◽  
Operating Conditions ◽  
Direct Photolysis ◽  
H2o2 System

Abstract The advanced oxidation technologies based on •OH can effectively degrade the pharmaceutical and personal care products under operating conditions of normal temperature and pressure. In this study, direct photolysis of ibuprofen (IBU) is slow due to the relatively low molar extinction coefficient and quantum yield. Compared to direct photolysis, the degradation kinetics of IBU was significantly enhanced in the UV/H2O2 system, mainly by •OH radical mediated oxidation. In the UV/H2O2 system, the degradation rate of ionic IBU was slightly faster than that of the molecular form. Kinetic analysis showed that the second-order reaction rate constant of ionic IBU (5.51 × 109 M−1 s−1) was higher than that of the molecular form (3.43 × 109 M−1 s−1). The pseudo first-order rate constant for IBU degradation (kobs) increased with increasing H2O2 dosage. kobs can be significantly decreased in the presence of natural organic matter (NOM), which is due to (i) NOM radical scavenging effects (dominant role) and (ii) UV absorption. The degradation of IBU was inhibited by HCO3–, which was attributed to its scavenging effect. Interestingly, when NO3– was present in aqueous solution, a slight increase in the degradation rate was observed, which was due to NO3– absorbing photons to generate •OH at a low quantum yield. No obvious effects were observed when SO42 and Cl− were present.

Immobilisation of Iron-Containing Materials onto Supporting Materials in Heterogeneous Fenton System: A Review

2014 ◽  
Vol 955-959 ◽  
pp. 569-580 ◽  
Author(s):  
Juan Chen
Keyword(s):  
Surface Area ◽  
Heterogeneous Fenton ◽  
Chemical Route ◽  
Advantages And Disadvantages ◽  
System A ◽  
Fenton Catalyst ◽  
Heterogeneous Fenton Catalyst ◽  
Supporting Materials ◽  
Fenton System

The purpose of this review is to aim a summary of the development in the use of different supports for the immobilisation of a heterogeneous Fenton catalyst, which areiron-containing materials. Various anchors and immobilisation methods that are universally employed to the remediation of wastewater are considered. Commonly, the immobilisation of a heterogeneous Fenton catalyst onto supportive material has chiefly been approved through one of two major routes; chemical route physical route or physical route. The advantages and disadvantages of various immobilisation methods to obtain a gigantic surface area iron-containing materials support is considered too.

Mahalanobis Taguchi system: a review

2015 ◽  
Vol 32 (3) ◽  
pp. 291-307 ◽  
Author(s):  
Elham Ghasemi ◽  
Abdollah Aaghaie ◽  
Elizabeth A. Cudney
Keyword(s):  
Pattern Recognition ◽  
Multivariate Analysis ◽  
Design Of Experiments ◽  
Case Studies ◽  
Design Methodology ◽  
Future Research ◽  
Content Type ◽  
Future Studies ◽  
System A ◽  
Selection Of

Purpose – The purpose of this paper is to present and analyze the current literature related to developing and improving the Mahalanobis-Taguchi system (MTS) and to present the shortcomings related to this method for future research. Design/methodology/approach – In this paper, articles in the literature are classified to give an overview on the MT strategy. For this purpose, 46 articles are considered for classification from 2000 to 2013 on the basis of: MTS contribution area, description of the issue, and results. Findings – In this paper a review on the concepts and operations of the MTS was provided as a new method in the field of pattern recognition, multivariable diagnosis, and forecasting. A large number of studies were performed in recent years consisting of developing MTS and MTS case studies. The analysis of the articles showed the fields of MTS which had more potential for future studies and developing. The comparison of the MTS to other methods and the selection of the normal group for constructing the Mahalanobis space have received the most attention by researchers. In addition, several studies concentrated on the use of other methods instead of design of experiments, finding applications for multiclass MTS and finding an alternative for the SN ratio. Originality/value – This paper contains the publications in the field of MTS chronologically and shows different areas for developing and case studies. It will be useful to researchers and professionals who are interested in pattern recognition, multivariate analysis, and forecasting.

scholarly journals ENVIRONMENTAL IMPLICATIONS ON THE HEALTH AND BEHAVIOUR OF THE TRAFFIC FORCE

2021 ◽  
Vol 03 (01) ◽  
pp. 33-39
Author(s):  
Basharat Ali ◽  
◽  
Umer Zafar ◽  
Muhammad Atif ◽  
◽  
...  
Keyword(s):  
Skin Diseases ◽  
Environmental Pollutants ◽  
Sampling Technique ◽  
Working Environment ◽  
Environmental Implications ◽  
Traffic Police ◽  
Multi Stage ◽  
Stress Oxidative ◽  
Surrounding Areas ◽  
And Behavior

The police hold a unique position in the society; Traffic Wardens play a very significant role in controlling the traffic system especially in the metropolitan and surrounding areas despite several limitations. The traffic police have the task which is more vital in the recent past, due to enormous growth in the numbers of various kinds of automobiles and road use. Traffic is managed by traffic police, who spent two thirds of their duty hours amidst of polluted working environment. Environmental pollutants have various adverse health consequences from minor to most important harmful fetal effects like prenatal disorders, infant mortality, respiratory disorders, allergy, malignancies, cardiovascular disorders, increase in stress oxidative, endothelial dysfunction, mental disorders, and various other harmful effects. Present study focused on the environmental implications on the health and behavior of the traffic force in District Faisalabad. Multi-stage sampling technique was used for data collection, while random sampling technique was used at all stages. Sampled shows that traffic warden faced many environmental pollutions borne diseases i.e. cough (76.7%), breath difficulty (51.3%), wheezing (5.3%), Running Nose (7.3%), Throat Irritation (40.0%), Throat diseases (33.3%), skin diseases (30.7%), viral hepatitis (21.3%), Congestion (16.0%) etc. Key words: Pollution, Environment, Health, Behavior, Traffic force, Disorder

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