Dissipation and gas chromatographic method for the determination of profenofos residues in/on green pea and cucumber

Herein we report a novel, accurate and cost-effective gas chromatography method for the determination of average deposits of profenofos on green pea and cucumber following good agricultural practices. Additionally the risk assessment, dissipation and waiting period for profenofos were determined. The average initial deposits (2 h after spraying) of profenofos in/on green pea and cucumber were 3.41 and 3.62 mg kg⁻¹ respectively following two applications at a 10 day interval of profenofos 50EC formulation. Profenofos residues on both of the substrates were below the detection limit of 0.05 mg kg⁻¹ after 20 days at the recommended dosage. For risk assessment studies, the 20th day will be safe for consumers for consumption of green peas. The gas chromatography method was validated according to the SANTE guidelines using the various analytical parameters: linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable and can be extended for profenofos-based standardization of pesticide formulations for green pea/cucumber and their use as pesticides.     

Study of traces of elements on a universal laser photoionization spectrometer

A new complex laser analytical spectrometer operating synchronously in the atomic beam regime and in the flame regime is developed. Analytical potentialities of the spectrometer are demonstrated by the example of determining sodium and calcium content in standard solutions and aluminum alloys. Processes of thermal atomization of Ca and Na in vacuum and the effect of the basis of a sample on the element determined are studied. Efficient excitation via Rydberg states is realized for these elements. The contents of Ca and Na in aluminum alloys are determined at levels of 10^?2 and 10^?3%, respectively.     

Substituents effect on thermal electrocyclic reaction of dihydroazulene–vinylheptafulvene photoswitch: a DFT study to improve the photoswitch

Thermal cyclization for a series of substituted vinylheptafulvenes (VHFs) to dihydroazulenes (DHAs) was studied at PBE0 method of density functional theory in the gas phase and in the acetonitrile solvent (through PCM). Judicious control of the thermal reaction through substituent is quite necessary to design thermally robust DHA–VHF photoswitches. For most of the substituents, DHA was predicted thermodynamically stable over VHF except for amino (in gas phase and solvent) and hydroxyl (in acetonitrile), where DHA isomers were calculated thermally unstable compared to VHF. Activation barriers for thermal electrocyclic reaction in both media showed positive correlation with Taft’s σ _R values at positions 7 and 5, however, a negative correlation was observed at position 4 and 6. The latter unprecedented behavior is proposed to arise from the delocalization of negative charges on the seven membered ring. Activation barriers for amino-substituted VHFs were generally lower than expected from Taft’s σ _R. A fluoro group at the position 7 was quite effective in imparting very high activation barrier (31.73 kcal mol^?1) for the thermal cyclization in the gas phase. However, in the acetonitrile solvent, the highest activation barriers were observed for electron withdrawing CHO (28.10 kcal mol^?1) and NO₂ (28.13 kcal mol^?1) groups at positions 7.     

On size-biased Consul distribution

In this paper, a size-biased Consul distribution (SBCOND) is defined. Recurrence relations for central moments and the moments about origin are obtained. Different estimation methods for the parameters of the model are discussed. A comparative analysis is done among the three different estimation methods and the proposed model is compared with the generalized logarithmic series distribution (GLSD) and simple Consul distribution.     

In vivo study of laser irradiation of fractionated drug administration based mechanism for effective photodynamic therapy in rat liver

Up-regulation of stress-activated proteins in cancer cells plays a protective role against photodynamic induced apoptosis. Post photodynamic therapy extracted normal rat liver tissue usually shows a fraction of surviving cells, the photodynamic resistant cells, residing in the necrotic region. To treat these photo-dynamic resistant cells a technique has been proposed based on fractionated drug administration of diluted photosensitizer, keeping the net concentration (5 mg/kg) constant, and subsequently varying drug light interval (DLI). Flourescence measurements were made for the presence of photosensitizer in a tissue. For qualitative analysis both histological and morphological studies were made. Although preliminary aim of this approach was not achieved but there were some interesting observation made i.e. for higher dilution of photosensitizer there was a sharp boundary between necrotic and normal portion of tissue. An increase in the absorption coefficient (α) from 2.7 → 2.9 was observed as photosensitizer was diluted while the corresponding threshold dose (D _th) persistently decreases from (0.10 → 0.02) J/cm² when irradiated with a 635 nm laser fluence of 150 J/cm².     

Regio- and stereoselective functionalization of alkenes with emphasis on mechanistic insight and sustainability concerns

Alkene is an attractive substrate for chemists due to its easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. It reacts under ionic and free radical mechanisms including single electron transfer (SET). In this review, strategies used for C–C and C-heteroatom functionalization of alkene has been discussed with emphasis on the regio, stereoselectivity, mechanistic detail and sustainability aspects. These strategies mainly follow the free radical mechanism, and the highly reactive carbon radicals show uncontrollable regio- and stereoselectivities. Thus these strategies still need to be focused; especially in the asymmetric versions. The regio- and stereoselectivities of functionalization of alkenes have been highlighted and debated. In addition, the hazardous reagents such as Cl₂, Br₂ I₂, CO, peroxides, and benzene have also been discussed with the emphasis on their impact on the environment. Their plausible green alternatives have also been suggested, such as MX as halogen replacement; CO surrogates (formaldehyde etc.); sustainable aromatic solvents as benzene replacement. The non-green strategies relying on pre-formed silyl hydride and their green alternative strategies such as transfer hydrogenations have also been indicated. The applications of the functionalization of alkenes for the total synthesis of bioactive compounds have also been discussed in detail. In addition, future perspectives are also highlighted for further developments in the functionalization of alkenes.     

Characteristics of Periodontal Tissues in Prosthetic Treatment with Fixed Dental Prostheses

The objective of the present study was to investigate the effects of various types of fixed prostheses on periodontal tissues and explore the association of gingival biotype and gum recession in relation to prosthesis types. The study participants (N = 95) were divided into three groups based on the type of dental prosthesis: Group-I: cobalt-chrome (Co-Cr) ceramic prosthesis fabricated by the conventional method (n = 35); Group-II: consisted of patients with Co-Cr ceramic prostheses fabricated by a computer-aided design and computer aided manufacturing (CAD/CAM) technique (n = 30); and Group-III: zirconia-based prostheses fabricated by the CAD/CAM technique (n = 30). Following the use of prostheses, periodontal examinations were performed using the Community Periodontal Index (CPI) and Modified Approximal Plaque Index (MAPI). In addition, the gingival biotype was examined using a probe transparency method. The Statistical Package for the Social Sciences (SPSS), Version 20 (IBM Company, Chicago, IL, USA), was used to analyze the results, and the significance level was set at p = 0.05. It showed the MAPI results after the use of prosthetic rehabilitation for 12 months of periodontitis in 87.9% ± 15.4 of patients in Group-I, in 80.6% ± 17.97 in those in Group-II, and in 62.5% ± 21.4 in those in Group-III (p < 0.01). The CPI index results indicated a high prevalence of periodontal disease in all groups. The number of people with healthy periodontium constituted 17.1% of patients in Group-I, 24.2% in Group-II, and 37.1% in Group-III. Our study concluded that prosthetic treatment with periodontal diseases showed better outcomes while using dental prostheses fabricated by the CAD/CAM technique compared to the conventionally fabricated dental prostheses. The thin gingival biotype is more often associated with gingival recession than the thick biotype.     

Biocomputational Assessment of Natural Compounds as a Potent Inhibitor to Quorum Sensors in Ralstonia solanacearum

Ralstonia solanacearum is among the most damaging bacterial phytopathogens with a wide number of hosts and a broad geographic distribution worldwide. The pathway of phenotype conversion (Phc) is operated by quorum-sensing signals and modulated through the (R)-methyl 3-hydroxypalmitate (3-OH PAME) in R. solanacearum. However, the molecular structures of the Phc pathway components are not yet established, and the structural consequences of 3-OH PAME on quorum sensing are not well studied. In this study, 3D structures of quorum-sensing proteins of the Phc pathway (PhcA and PhcR) were computationally modeled, followed by the virtual screening of the natural compounds library against the predicted active site residues of PhcA and PhcR proteins that could be employed in limiting signaling through 3-OH PAME. Two of the best scoring common ligands ZINC000014762512 and ZINC000011865192 for PhcA and PhcR were further analyzed utilizing orbital energies such as HOMO and LUMO, followed by molecular dynamics simulations of the complexes for 100 ns to determine the ligands binding stability. The findings indicate that ZINC000014762512 and ZINC000011865192 may be capable of inhibiting both PhcA and PhcR. We believe that, after further validation, these compounds may have the potential to disrupt bacterial quorum sensing and thus control this devastating phytopathogenic bacterial pathogen.     

Potential Therapeutic Benefits of Honey in Neurological Disorders: The Role of Polyphenols

Honey is the principal premier product of beekeeping familiar to Homo for centuries. In every geological era and culture, evidence can be traced to the potential usefulness of honey in several ailments. With the advent of recent scientific approaches, honey has been proclaimed as a potent complementary and alternative medicine for the management and treatment of several maladies including various neurological disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and multiple sclerosis, etc. In the literature archive, oxidative stress and the deprivation of antioxidants are believed to be the paramount cause of many of these neuropathies. Since different types of honey are abundant with certain antioxidants, primarily in the form of diverse polyphenols, honey is undoubtedly a strong pharmaceutic candidate against multiple neurological diseases. In this review, we have indexed and comprehended the involved mechanisms of various constituent polyphenols including different phenolic acids, flavonoids, and other phytochemicals that manifest multiple antioxidant effects in various neurological disorders. All these mechanistic interpretations of the nutritious components of honey explain and justify the potential recommendation of sweet nectar in ameliorating the burden of neurological disorders that have significantly increased across the world in the last few decades.     

Correlation Between the Scaling Factor of the Yukawa Coupling and Cross Section for the e + e − → h h f f ¯ $e^{+} e^{-} \rightarrow hhf\overline {f}$ (f≠t) in Type-I 2HDM

International Journal of Theoretical Physics - The objective of this study is to correlate the scaling factor of the Standard Model (SM) like Higgs boson and the cross section ratio of the process...