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Chloropropanols such as 3-monochloropropane-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) have drawn increasing attention due to their release from food contact paper and their potential carcinogenic effects. In this study, the effects were investigated of water extraction conditions on release of chloropropanols from food contact paper, and the extraction efficiencies of chloropropanols by water extract and migration method were compared. Cold water was found to be more severe than hot water for extraction of chloropropanols, with the highest water extraction value obtained at 23°C. Two hours of extraction was sufficient as the chloropropanols can be fully extracted from food contact paper within a short period of time. Increase of temperature in the range of 10°C–60°C had little impact on release of chloropropanols, however, the extraction of chloropropanols decreased when high temperatures (80°C or above) were applied due to volatilisation losses. Hence, attention should be paid when choosing extract conditions representing the worst-case scenario. The water extraction value using EN 645 method gives higher results compared to migration test described in GB 31604.1 and GB 5009.156, suggesting that the water extract method was probably more severe. For migration test, aqueous-based simulants were found to be more conservative than oil-based simulants, suggesting the conventional experiment conditions applicable for compliance test of chloropropanols migration can be simplified and optimised. [ABSTRACT FROM AUTHOR]

A pre-column derivatization method for the sensitive determination of aliphatic amines using the labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) followed by HPLC with fluorescence detection and APCI/MS identification in positive-ion mode has been developed. The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent was replaced by the 1,2-benzo-3,4-dihydrocarbazole functional group, which resulted in a sensitive fluorescence derivatizing reagent, BCEOC, that could easily and quickly label amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+H]+ with APCI/MS in positive-ion mode. The collision induced dissociation of the protonated molecular ion formed characteristic fragment ions at m/z 264.1, m/z 246.0 and m/z 218.1, corresponding to the cleavages of CH2CH2O-CO, CH2CH2-OCO, and N-CH2CH2O bonds. Studies on derivatization conditions demonstrated that excellent derivatization yields close to 100% were observed with a 3 to 4-fold molar reagent excess in acetonitrile solvent, in the presence of borate buffer (pH 9.0) at 40°C for 10 min. In addition, the detection responses for BCEOC derivatives were compared with those obtained with CEOC and FMOC as labeling reagents. The ratios IBCEOC/ICEOC and IBCEOC/IFMOC were, respectively, 1.40-2.76 and 1.36-2.92 for fluorescence responses (here, I was the relative fluorescence intensity). Separation of the amine derivatives had been optimized on an Eclipse XDB-C8 column. Detection limits calculated from an 0.10 pmol injection, at a signal-to-noise ratio of 3, were 18.65-38.82 fmol (injection volume 10 µL) for fluorescence detection. The relative standard deviations for intraday determination (n=6) of standard amine derivatives (50 pmol) were 0.0063-0.037% for retention times and 3.36-6.93% for peak areas. The mean intra- and inter-assay precision for all amines were <5.4% and 5.8%, respectively. The recoveries of amines ranged from 96 to 113%. Excellent linear responses were observed with correlation coefficients of >0.9994. The established method provided a simple and highly sensitive technique for the quantitative analysis of trace amounts of aliphatic amines from biological and natural environmental samples. [ABSTRACT FROM AUTHOR]

Thermal paper poses a significant challenge to latent print development as it tends to change color when traditional fingerprint development formulations are applied to it. In this study, the optimal components of ninhydrin, 1,2-indanedione, 1,8-diazafluoren-9-one ( DFO), and 5-methylthioninhydrin (5- MTN) for yielding clear fingerprints on thermal paper were determined by systematically adjusting the relative amounts of the reagents, polar solvents, and the nonpolar diluent petroleum ether, followed by validation on text-printed thermal paper. Specifically, 3.0% ethyl acetate as the polar solvent in petroleum ether was found to be the optimal combination; the optimal dilution ratios of ninhydrin, DFO, and 5- MTN original solutions with petroleum ether were 1 to 2, 11, and 7, respectively. The optimal concentration of 1,2-indanedione in petroleum ether was 0.125 g/L, with a string of 0.5% ethyl acetate in petroleum ether. [ABSTRACT FROM AUTHOR]

Abstract: We revisit an old Russian paper by V.V. Dynnik, R. Heinrich and E.E. Sel’kov (1980a,b) describing: “A mathematical model of carbohydrate energy metabolism. Interaction between glycolysis, the Krebs cycle and the H-transporting shuttles at varying ATPases load”. We analyse the model mathematically and calculate the control coefficients as a function of ATPase loads. We also evaluate the structure of the metabolic network in terms of elementary flux modes. We show how this model can respond to an ATPase load as well as to the glucose supply. We also show how this simple model can help in understanding the articulation between the major blocks of energetic metabolism, i.e. glycolysis, the Krebs cycle and the H-transporting shuttles. [Copyright &y& Elsevier]

Abstract: 1,2-Indanedione treated fingerprints deposited on two substrates (thermal and carbonless paper) were swabbed and tested to determine the effect of the chemical on PCR-STR DNA typing. Samples from 10 post-treatment intervals were analyzed. Two extraction methods, Chelex® and Qiamp, were used to determine the effect of extraction procedure on the quality of the DNA profiles. The LCN DNA samples were concentrated using Microcon® 100 and amplified using the Profiler Plus amplification kit. 1,2-Indanedione did not adversely affect the DNA profiles obtained from the treated fingerprints. Partial DNA profiles were obtained at all post-development time frames. Both extraction methods produced comparable profiles although more “drop-ins” were observed with the Qiamp method. More “drop-outs” occurred in the DNA profiles from samples deposited on the thermal substrate compared with carbonless substrate. [Copyright &y& Elsevier]

Over the years, some activist groups have targeted cosmetics as possible human health threats, claiming that cosmetic ingredients are not adequately tested for safety and may pose risks to consumers. The groups allege that industry practices related to safety testing are flawed, that there is little government oversight, and that cosmetics contain cancer-causing chemicals and other toxicants. A critical review of the scientific data related to these claims indicates the following: (1) Industry has the primary responsibility to ensure that all ingredients, preservatives, and coformulants used in products are safe for their intended uses. (2) The U.S. Food and Drug Administration (FDA) has regulatory oversight of the cosmetic industry. Its authority includes the banning or restriction of ingredients for safety reasons. (3) The Cosmetic Ingredient Review (CIR), an independent, scientific review board, critically evaluates chemical ingredients used in cosmetics and publishes the results of its findings in the peer-reviewed literature. (4) Health-related allegations about cosmetic ingredients are generally based on the results of high-dose laboratory testing in animals and have little relevance for humans. As true now as when Paracelsus said it in the 16th century, “It is the dose that makes the poison.” (5) The health-related allegations involving specific chemicals (e.g., phthalates, parabens, and 1,3-butadiene) fail to consider important scientific studies and recent regulatory conclusions about these chemicals, which have found that they are not hazardous. (6) Animal and human physiology differ in crucial ways, further invalidating simplistic attempts to extrapolate rodent testing to human health risks. The cosmetic industry should be encouraged to publish more of its toxicity studies and safety evaluations, which would aid in dispelling the uncertainty that some consumers have about cosmetic safety. [ABSTRACT FROM AUTHOR]

Woollins reagent was found to act as a highly chemoselective reagent for the reduction of a wide range of 1,4-enediones and 1,4-ynediones in methanol to afford the corresponding saturated 1,4-diketones in good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

The presented paper investigates the creation of chitosan-based composites on the surface of chemically modified poly-D-lactic acid (PDLA). PDLA was dissolved in chloroform and cast into a glass dish until the complete evaporation of the solvent. The surface of the created PDLA films was modified with 1,6-hexanediamine and glutaraldehyde for the creation of free aldehyde side groups. Composite layers of chitosan (CH) were deposited on the surface of the modified films. The mechanical properties of the composite films were investigated using a dynamometer. The surface morphology of the created composite films was studied with Scanning electron microscopy (SEM). Sessile drop method was used to determine the surface free energy of the created chitosan-based composite layers. [ABSTRACT FROM AUTHOR]

From 15 May to 15 December 1994, 2943 patients suspected of having contact dermatitis (1955 women, 988 men) were patch tested with methyldibromoglutaronitrile 0.3%, 0.1% and .05% pet. 119 patients (4.0% women, 4.1% men, 3.8%) proved to be allergic. 71% of the reactions were considered to be relevant. In 2/3 of the patients, causative products were cosmetics, in 1/3 moistened toilet tissues. Testing with methyldibromoglutaronitrile at lower concentrations 0.05% and 0.1%) and with commercial allergens (Euxyl® K 400 and methyldibromoglutaronitrile, both containing methyldibromoglutaronitrile 0.1%), resulted in a number of false-negative reactions. All preservatives in the European standard series had lower scores than the 4% positive reactions to methyldibromoglutaronitrile (formaldehyde 2.0%. MCI/MI (Kathon® CG) 3.2% parabens, 1.0% quaternium-15 1.3%). It is concluded that methydibromoglutaronitrile (present in the commercial preservative Euxyl® K 400) is an important contact allergen in the Netherlands in cosmetics and moistened toilet tissues. It should be added to cosmetics series and to proctological series. The optimal test concentration is unknow, but may be 0.3%. pet. Th concentration of 0.1% methyldibromoglutaronitrile in the currently available commercial allergens appears to be too low, resulting in a number of false-negative reactions. [ABSTRACT FROM AUTHOR]

The development of 1,8-naphthalimide derivatives as cell probes, DNA targeting agents, and anti-tumor drugs is one of the research hotspots in the field of medicine. Naphthalimide compounds are a kind of DNA embedder, which can change the topological structure of DNA by embedding in the middle of DNA base pairs, and then affect the recognition and action of topoisomerase on DNA. Aminofide and mitonafide are the first 2 drugs to undergo clinical trials. They have good DNA insertion ability, can embed DNA double-stranded structure, and induce topoisomerase II to cut part of pBR322DNA, but not yet entered the market due to their toxicity. In this paper, the design and structure-activity relationship of mononaphthalimide and bisaphthalimide compounds were studied, and the relationship between the structure of naphthalimide and anti-tumor activity was analyzed and discussed. It was found that a variety of structural modifications were significant in improving anti-tumor activity and reducing toxicity. [ABSTRACT FROM AUTHOR]

In this paper, we define a new type of open sets called co-Lindelöf open set (coL-open). Moreover, we obtain several results about co-Lindelöf open sets and study the relation among open set, coc-open set and coL-open. Furthermore, we define separation axioms via coLopen and prove some related results. [ABSTRACT FROM AUTHOR]

Three relatively new reagents for developing latent fingermarks on porous substrates, 1,2-indandione (IND), 5-methylthioninhydrin (5-MTN), and lawsone, are compared with the more widely used ninhydrin and 1,8-diazofluoren (DFO). Developed latent fingermark visualization on 10 different substrates comprising colored papers, cardboard, and cellophane rather than conventional printer and writing/notepad paper is assessed using latent fingermark deposits from 48 donors. Results show improved fluorescent fingermark visualization using IND compared with DFO on a range of colored cardboards and thick white paper, thus extending the range of substrates known to yield improved visualization with IND. Adding zinc chloride to IND failed to yield any further improvement in fluorescent fingermark visualization. 5-MTN (with and without zinc chloride posttreatment) showed no improvement in visualization compared with ninhydrin and DFO although visible fingermarks were developed. Lawsone produced fluorescent visible fingermarks only with white substrates, which were inferior to those produced with DFO. [ABSTRACT FROM AUTHOR]

A thin film of poly-([IrCl(cod)(NHC-onbe)] n-(propyl-onbe) m) (onbe=oxanorbornene) coated on filter paper reacts quantitatively with CO to yield 1,5-cyclooctadiene, the unpleasant smell of which can be detected by the human olfactory system with very high sensitivity. Odorless, but toxic CO is thus 'translated' into the distinct smell of 1,5-cyclooctadiene. Based on malodorogenic sensing it is possible to smell the presence of CO. [ABSTRACT FROM AUTHOR]

Point-of-care testing (POCT) technology allows scientists to monitor and diagnose diseases at the patient site, much faster than classical lab-based methods. Herein, a rapid, simple, and sensitive 3D printed microfluidic device integrated with smartphone-based on-chip detection is described for POCT quantification of urinary uric acid. The device includes two circular inputs each connected to a microliter-scale chamber, separated by an integrated porous membrane, located between the sample and reagent chambers. The microfluidic device was fabricated from a transparent photopolymer using a 3D printer, in a single run. The concentration of uric acid was determined based on a chromogenic reaction in which ferrous ion, produced via the reduction of ferric ion by the analyte, complexed with 1,10-phenanthroline, and the color was recorded by a smartphone. Response surface methodology including a central composed design was utilized to evaluate the experimental parameters and subsequent introduction of a multivariate model to describe the experimental conditions. Under the optimum conditions, the calibration curve was linear over the concentration range of 30–600 mg L−1. The limit of detection was determined to be 10.5 mg L−1. The microfluidic device was successfully utilized for the recovery and quantification of uric acid in the urine, with recoveries ranging from 91.7 to 99.7%. A microfluidic device was 3D printed for the determination of uric acid levels in urine. The device was coupled with a smartphone-based colorimetric method. Response surface methodology including central composed design was used to optimize experimental variables. This device shows promise for the evaluation of renal and kidney function. [ABSTRACT FROM AUTHOR]

Copyright of Bankarstvo Magazine is the property of Association of Serbian Banks and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Occupational contact allergy to 1,2-benzisothiazolin-3-one (1,2-BIT. Proxel®) is analysed. This compound is widely used in industry as a preservative in water-based solutions such as pastes, paints and cutting oils. The optimal concentration for patch testing proved to be 0.4 g/1 (0.04%) in water. In 4 out of 17 patients (23%) at occupational risk (painters, paper-hangers), contact allergy to 1,2-BIT was found. Of 556 consecutive dermatological patients without clear occupational risk, 10 (1.8%) showed positive patch tests to 1.2-BIT in 3 patients 1,2-BIT contact allergy was related to domestic paper-hanging. Although the chemical structure of 1,2-BIT shows some analogy with the preservative Kathon® CG, true cross-sensitivity was found to be unlikely. [ABSTRACT FROM AUTHOR]

This paper investigates the optimal tracking performance based on the codec, colored noise, and bandwidth constraints in the network time‐delay systems. Choosing the optimal two‐degree‐of‐freedom compensator and the dominant expression of the system optimal tracking performance is obtained after Youla parameterization by using the coprime factorizations method and spectral decomposition technology. The result shows that the tracking performance of the system is determined by the nonminimum phase zero and unstable pole of the controlled plant. Moreover, codec, colored noise, and bandwidth constraints can also significantly impact the performance. Finally, two simulation examples prove the accuracy of the theory. [ABSTRACT FROM AUTHOR]

Supramolecular gels with metal ion-responsiveness are an important kind of smart materials due to their potential application in environmental monitoring. In this study, a novel l -glutamine-contained 1,8-naphthalimide derivative (NDG) has been designed and synthesized as an organogelator. NDG could self-assemble into stable supramolecular organogels in different kind of solvents, and the gelation process showed bright blue aggregation-induced emission (AIE). The self-assembly behavior, morphology and structure of NDG gels were thoroughly studied by various techniques. Interestingly, the obtained NDG organogel exhibited a fluorescence "turn-off" response for Fe3+ and formed a stable metallogel NDG -Fe3+. The detection limit (LOD) of NDG in diluted solution and gel states for Fe3+ was calculated to be 30.8 nM and 11.5 nM, respectively, indicating high sensitivity. In addition, the blue fluorescence emission of the gel system was restored in the presence of ascorbic acid and then quenched again with oxygen, which showed reversible fluorescence sensing effect and employed as a logic gate at the molecular level. Furthermore, xerogel-based film of NDG emitted strong blue emission and could be utilized as paper-based chemosensor to detect Fe3+. And also, the NDG gel had potential application in fluorescence display material. [Display omitted] • A l -glutamine-contained 1,8-naphthalimide gelator was synthesized with AIE effect. • The organogel exhibited a fluorescence response for Fe3+ by gel-gel transition. • The gel system was potentially constructed as a molecular logic gate. • Paper-based gel film was used in Fe3+ recognition and as display material. [ABSTRACT FROM AUTHOR]

Abstract: The aryl hydrocarbon receptor (AHR) participates in a wide range of critical cellular events in response to endogenous signals or xenobiotic chemicals. Hence, it is important that AHR levels and activity themselves be well controlled in target tissues. The AHR is essentially ubiquitous in its distribution in mammalian tissues. However, levels of the receptor vary widely across different tissues and among different cell types. AHR levels and activity are modulated by exposure to the receptor''s own ligands and are influenced by other xenobiotic chemicals. Many different factors impinge on AHR levels and AHR activity. These factors may alter responsiveness of downstream pathways, thereby affecting normal physiologic functions as well as responses to toxic environmental chemicals such as dioxins. Our commentary appraises the current literature on factors that regulate AHR levels/activity and attempts to identify fruitful strategies towards discovery of key pathways by which AHR levels are modulated in response to endogenous signals and in response to xenobiotic chemicals. An extraordinarily large number of agents alter the level or activity of the AHR. We have not yet entered an age of enlightenment sufficient to achieve true understanding of the interplay of mechanisms that regulate AHR expression in space and in time. [Copyright &y& Elsevier]

In this paper, a cyclotetrasiloxane modified with epoxy resin was synthesized via hydrosilylation with 1, 3, 5, 7-tetramethylcyclotetrasiloxane (D4H) and 4-vinyl-1-cyclohexane 1, 2-epoxide (VCHO). The structure of tetramethylcyclotetrasiloxane modified with cyclohexane epoxide (D4H–VCHO) was characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). The effects of feeding methods, feeding ratios, catalyst dosages, reaction temperature and reaction time on the products were investigated. After 4-h reaction with 8 ppm catalyst at 90 °C, D4H–VCHO was obtained with an epoxy value of 0.521 and a refractive index of 1.4920. Then, with 4-methylhexahydrophthalic anhydride as a curing agent and tetrabutylammonium bromide as a catalyst, the obtained D4H–VCHO was cured at 90 °C for 1 h and then 120 °C for another hour. The cured products showed high light transmittance, strong thermal stability, suitable hardness and low water absorption. The glass transition temperature of cured materials was 151.6 °C, indicating the improvement of flexibility. In addition, the introduction of epoxy groups greatly enhanced the adhesion of silicone resins to substrates. The results demonstrated that the epoxy-modified silicone materials could be applied as LED packaging materials. [ABSTRACT FROM AUTHOR]

A vertex subset S of a graph G = (V , E) is a [ 1 , 2 ] -dominating set if each vertex of V ∖ S is adjacent to either one or two vertices in S. The minimum cardinality of a [ 1 , 2 ] -dominating set of G , denoted by γ [ 1 , 2 ] (G) , is called the [ 1 , 2 ] -domination number of G. In this paper, the [ 1 , 2 ] -domination and the [ 1 , 2 ] -total domination numbers of the generalized Petersen graphs P (n , 2) are determined. [ABSTRACT FROM AUTHOR]

Several notions on soft topology are studied and their basic properties are investigated by using the concept of soft pre open sets and soft pre closure operator which are derived from the basics of soft set theory established by Molodtsov [1]. In this paper we introduce some soft separation axioms called Soft pre R0 and soft pre R1 in soft topological spaces which are defined over an initial universe with a fixed set of parameters. Many characterizations and properties of these spaces have been demonstrated. Necessary and sufficient conditions for a soft topological space to be a soft pre Ri space for i = 0, 1 were also presented. Furthermore, the concept of functions with soft pre closed graph and soft pre cluster set are defined. Many results on these two concepts are proved. Also, it is proved that a function has a soft pre closed graph if and only if its soft pre cluster set is degenerate. ©2022 All rights reserved. [ABSTRACT FROM AUTHOR]

In this paper, diamine monomers with ether bonds in the main chain are selected for molecular structure design, and four polyamide-imide (PAI) materials are prepared by the acyl chloride method. A diamine monomer containing an ether group can reduce the friction coefficient and improve the wear performance of PAI material. The wear mechanism of PAI material can also change due to ether linkages. PAI synthesized using m -phenylenediamine without an ether bond has the highest friction coefficient and abrasion loss, and the wear mechanism is mainly adhesive wear. With the increase of the number of ether bonds in the diamine monomer structure, the friction coefficient of the material decreases from 0.5445 to 0.4216 (22.57 %). The abrasion loss of the PAI material synthesized using 4,4′-diaminodiphenyl ether is the smallest, which is 84.4 % lower than m -phenylenediamine. The wear mechanism is abrasive wear and slight adhesion wear. With the increase of the number of ether bonds, the heat r esistance of PAI decreases slightly, while the hydrophobic property increases and the water absorption decreases. To summarise, PAI material synthesized using 4,4′-diaminodiphenyl ether has a low friction coefficient, the best wear resistance, the highest tensile strength and elongation at break, and the best comprehensive properties of the materials reported here. A diamine monomer containing an ether group can reduce the friction coefficient and improve the wear performance of PAI material, and the wear mechanism of the PAI material can also change due to ether linkages. [ABSTRACT FROM AUTHOR]

Hydrazine (N 2 H 4), as a highly reducing agent and reactive base, is extensively utilized in chemical, pharmaceutical and agriculture fields. However, the high toxicity of N 2 H 4 poses significant risks to human health and can lead to severe ecological contamination. Consequently, it is of significant to develop a tool for the detection of N 2 H 4 in the environment fields and in vivo. Herein, three 1,8-naphthalimide-triphenylamine-based red-emitting fluorescence probes (TSY-1 , TSY-2 and TSY-3) have been developed for the detection of N 2 H 4 in actual water sample and in vivo by coupling of 1,8-naphthalimide derivatives with the electron-withdrawing groups (1,3-indandione, malononitrile, and 2-benzothiazolethonitrile) through a N 2 H 4 responsive C C bond. Significant fluorescence quenching of three probes was observed on account of the responses toward N 2 H 4. The detection limits of TSY-1 , TSY-2 and TSY-3 for N 2 H 4 were calculated to be 0.2 μM, 0.4 μM and 54 μM, respectively. Utilizations of probe-based test paper strips to qualitatively detect N 2 H 4 in actual water sample by "naked-eye" colorimetry were demonstrated. Additionally, quantitative determination of N 2 H 4 in actual water samples was successfully achieved by the smartphone-based standard curves. Additionally, the applications of TSY-1 , TSY-2 and TSY-3 in fluorescence imaging N 2 H 4 in vivo are also demonstrated. [Display omitted] • Three red emitting probes are developed for high selective and sensitive detection of N 2 H 2 in water of wide pH range. • Probe-based test paper strips for "naked-eye" detection of N 2 H 4 level in real-world water samples are obtained. • Determination of N 2 H 4 in real-world water samples is achieved by the smartphone-based approach. • Applications of the three probes in fluorescence imaging of N 2 H 4 in vivo are demonstrated. [ABSTRACT FROM AUTHOR]

Environmental concerns from global warming and climate change demand carbon dioxide separation from post-combustion gases. Important parameters are involved in choosing the suitable solvent for carbon dioxide separation, including the reaction rate of carbon dioxide and the solvent. In this paper, the kinetics of carbon dioxide (CO2) absorption in aqueous solutions of Monoethanolamine (MEA) + 1,3-Diaminopropane (DAP), a diamine containing two primary amino group, was developed. The measurements were performed in a stirred cell with a horizontal gas-liquid interface in the temperature range of 313.15–333.15 K and aqueous solutions of 10 wt% MEA + 5 wt% DAP and 12.5 wt% MEA + 2.5 wt% DAP. Experiments were conducted in an isothermal batch reactor with a horizontal gas-liquid interface under pseudo-first-order conditions, enabling the determination of the overall kinetic rate constant from the pressure drop method. Second-order reaction rate constants of CO2 absorption in amine solutions were estimated using the calculated initial absorption rate. It was found that the rate constants in MEA+ DAP solutions were greater than in MEA solutions which means that DAP increases the reaction rate. [ABSTRACT FROM AUTHOR]

It is a well-known fact that by changing the 1,3-dipolar cycloaddition (1,3- DC) reaction mechanism from concerted to stepwise, the stereospecificity is lost; since in synthesizing the required heterocyclic molecules that reaction is a requisite, it is important to study the concertedness of that reaction. Several papers on this subject have already stated that the existence of electron withdrawing groups ( EWG) or electron donor groups ( EDG) on dipole or dipolarophile leads to a high-energy differentiation between the dipole HOMO and dipolarophile LUMO (or vice versa) as well as the emergence of an intermediate in the reaction pathway. This paper seeks answering the question of when an EWG on dipole and an EDG on dipolarophile could be a factor in making the reaction mechanism stepwise, and does repositioning of functional groups in replacing dipole and dipolarophile switches the reaction mechanism from stepwise into concerted or vice versa? [ABSTRACT FROM AUTHOR]