Preparation of CdS/BiOCl/Bi₂O₃ double composite system for visible light active photocatalytic applications

Chakraborty, Ashok Kumar,Ganguli, Sumon,Bera, Sandipan,Lee, Wan In Elsevier 2018 Journal of photochemistry and photobiology Chemist Vol.364 No.-

<P><B>Abstract</B></P> <P>An efficient visible-light-harvesting (λ ≥ 420 nm) three component system heterojunction photocatalyst, CdS/BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> was prepared by anchoring of CdS nanoparticles on the surface of BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite. The effect of CdS nanoparticles on the surface of BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite photocatalyst had been justified in enhancing photocatalytic activity towards the degradation of organic pollutants in gas as well as aqueous phase. With the loading of CdS on to the BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> heterojunction composite photocatalyst, the photocatalytic activity of the CdS/BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite structure has been appreciably improved for the decomposition of 2-propanol (IPA) in gas phase and salicylic acid (SA) in aqueous phase under visible light irradiation (λ ≥ 420 nm). The amount of loading of CdS nanoparticles was optimized to 2 mol% CdS/BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB>. Compare to bare BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> photocatalyst, CdS/BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> heterojunction demonstrated 2 times decomposition of IPA in gas phase and 1.8 times of SA in aqueous phase after 120 min. of visible light irradiation. At the same time, with this composition the evolution of CO<SUB>2</SUB> from degradation of IPA was 1.9 times higher than that of BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite. The enhanced photocatalytic efficiency is deduced from the electron (eˉ) and hole (h<SUP>+</SUP>) transfer among the component semiconductor nanoparticles Bi<SUB>2</SUB>O<SUB>3</SUB>, BiOCl and CdS due to their relative energy band positions. Several experimental evidences were also provided to confirm the electron-hole transfer among the semiconductors and a mechanistic way has been proposed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CdS has been successfully anchored on to the surface of BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite photocatalyst. </LI> <LI> CdS/BiOCl/Bi<SUB>2</SUB>O<SUB>3</SUB> composite photocatalyst demonstrated higher absorption towards visible light. </LI> <LI> Recombination of photoexcited electrons (e<SUP>−</SUP>) and holes (h<SUP>+</SUP>) has been effectively inhibited. </LI> <LI> Photoinduced hole (h<SUP>+</SUP>) and hydroxyl radical (OH) has been experimentally proved. </LI> <LI> Photocatalytic activity has been remarkably enhanced under visible light. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

RICARDIAN EQUIVALENCE : FURTHER EVIDENCE

CHAKRABORTY, ATREYA,FARAH, ABDIKARIM M . 한국국제경제학회 1996 International Economic Journal Vol.10 No.3

Micro-Environmental Signature of The Interactions between Druggable Target Protein, Dipeptidyl Peptidase-IV, and Anti-Diabetic Drugs

Chakraborty, Chiranjib,Mallick, Bidyut,Sharma, Ashish Ranjan,Sharma, Garima,Jagga, Supriya,Doss, C George Priya,Nam, Ju-Suk,Lee, Sang-Soo Royan Institute 2017 Cell journal (Yakhteh) Vol.19 No.1

<P><B>Objective</B></P><P> Druggability of a target protein depends on the interacting micro-environment between the target protein and drugs. Therefore, a precise knowledge of the interacting micro-environment between the target protein and drugs is requisite for drug discovery process. To understand such micro-environment, we performed in silico interaction analysis between a human target protein, Dipeptidyl Peptidase-IV (DPP-4), and three anti-diabetic drugs (saxagliptin, linagliptin and vildagliptin). </P><P><B>Materials and Methods</B></P><P> During the theoretical and bioinformatics analysis of micro-environmental properties, we performed drug-likeness study, protein active site predictions, docking analysis and residual interactions with the protein-drug interface. Micro-environmental landscape properties were evaluated through various parameters such as binding energy, intermolecular energy, electrostatic energy, van der Waals’+H-bond+desolvo energy (E<SUB>VHD</SUB>) and ligand efficiency (LE) using different in silico methods. For this study, we have used several servers and software, such as Molsoft prediction server, CASTp server, AutoDock software and LIGPLOT server. </P><P><B>Results</B></P><P> Through micro-environmental study, highest log P value was observed for linagliptin (1.07). Lowest binding energy was also observed for linagliptin with DPP-4 in the binding plot. We also identified the number of H-bonds and residues involved in the hydrophobic interactions between the DPP-4 and the anti-diabetic drugs. During interaction, two H-bonds and nine residues, two H-bonds and eleven residues as well as four H-bonds and nine residues were found between the saxagliptin, linagliptin as well as vildagliptin cases and DPP-4, respectively. </P><P><B>Conclusion</B></P><P>Our in silico data obtained for drug-target interactions and micro-environmental signature demonstrates linagliptin as the most stable interacting drug among the tested anti-diabetic medicines.</P>

Effect of Space Charge Density and High Voltage Breakdown of Surface Modified Alumina Reinforced Epoxy Composites

Chakraborty, Himel,Sinha, Arijit,Chabri, Sumit,Bhowmik, Nandagopal The Korean Institute of Electrical and Electronic 2013 Transactions on Electrical and Electronic Material Vol.14 No.3

The incorporation of 90 nm alumina particles into an epoxy matrix to form a composite microstructure is described in present study. It is shown that the use of ultrafine particles results in a substantial change in the behavior of the composite, which can be traced to the mitigation of internal charges when a comparison is made with conventional $Al_2O_3$ fillers. A variety of diagnostic techniques have been used to augment pulsed electro-acoustic space charge measurement to provide a basis for understanding the underlying physics of the phenomenon. It would appear that, when the size of the inclusions becomes small enough, they act cooperatively with the host structure and cease to exhibit interfacial properties. It is postulated that the $Al_2O_3$ particles are surrounded by high charge concentrations. Since $Al_2O_3$ particles have very high specific areas, these regions allow limited charge percolation through $Al_2O_3$ filled dielectrics. The practical consequences of this have also been explored in terms of the electric strength exhibited. It would appear that there was a window in which real advantages accumulated from the nano-formulated material. An optimum filler loading of about 0.5 wt.% was indicated.

Exploring the neural mechanisms of aversion to bitter gourd phytochemicals in insects using Drosophila

Chakraborty Rusha,Thakur Tamanna Singh,Chauhan Riti,Manzar Zeba,Das Gaurav,Mitra Aniruddha 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Bitter gourd (Momordica charantia L.) has compounds that repel insect pests. Unlike conventional pesticides, these compounds are eco-friendly and beneficial for human health. However the mechanisms by which these compounds repel insects and affect their physiology remains poorly known. Here we used Drosophila melanogaster (Meigen) to address these issues. We tested a wild strain, and a laboratory bred Canton S strain. Bitter gourd extract reduced the viability of developing flies, but did not affect survival in adults. Flies avoided bitter gourd extract in a food choice assay, and consumed a significantly low amount of food mixed with bitter gourd – indicating that it acts as an antifeedant. Transgenic flies with impaired aversive taste sensitive neurons showed a reduced aversion towards bitter gourd extract showing that these compounds act through the bitter sensitive gustatory neurons. Finally, flies also retained the memory of consuming bitter gourd extract for at least 24 hours, suggesting an additional cognitive mechanism for long term aversion. Our study provides the first evidence of bitter gourd compounds acting as antifeedants and also as potent reinforcers of aversive memory in drosophilids. We suggest that flies can be used to understand the physiological and neural mechanisms underlying the mode of action of other such phyto-extracts with the goal of developing potent but less harmful pest control formulations.

Spirituality bestowing self-transcendence amid COVID-19 through slow fashion

Chakraborty Swagata,Sadachar Amrut 한국마케팅과학회 2023 Journal of Global Fashion Marketing Vol.14 No.3

We proposed and tested a conceptual model exploring how (i) COVID-stress evokes spirituality; (ii) COVID-stress and spirituality engender positive attitude toward the different dimensions of slow fashion (i.e. equity, authenticity, functionality, localism, and exclusivity) as a symbol of self-transcendence and (iii) spirituality mediates the relationships between COVID-stress and the different dimensions of slow fashion. We conducted an online survey in Amazon Mechanical Turk (n = 317) and analyzed the data through structural equation modeling. (i) COVID-stress positively influences spirituality; (ii) both COVID-stress and spirituality positively influ- ence attitude toward slow fashion in terms of equity, authenticity, localism, and exclusivity; (iii) spirituality mediates the relationships between COVID-stress and all the dimensions of slow fashion except for functionality. Due to the fast-changing situations amid the pandemic and the uneven severity of the pandemic globally, a cross-sectional study may have limited the scope for capturing nuances of retail consumer behavior. In summary, we suggest that the consumption of slow fashion apparel as a symbol of self- transcendence may help consumers cope with COVID-stress in the hope of building spiritual ties with a higher power through the process of ethical consumption amid the pandemic.

Absence of 185delAG and 6174delT Mutations among Breast Cancer Patients of Eastern India

Chakraborty, Abhijit,Banerjee, Debolina,Basak, Jayasri,Mukhopadhyay, Ashis Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females, pushing the cervical cancer to the second position. Most of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in two tumor suppressor genes BRCA1 and BRCA2. Alterations in these genes have been reported in different populations, some of which are population-specific mutations showing founder effects. Two specific mutations in the BRCA1 (185delAG) and BRCA2 (6174delT) genes have been reported to be of high prevalence in different populations. The aim of this study was to estimate the carrier frequency of 185delAG and 6174delT mutations in eastern Indian breast cancer patients. Materials and Methods: We selected 231 histologically confirmed breast cancer patients from our tertiary cancer care center in eastern India. Family history was obtained by interview or a self-reported questionnaire. The presence of the mutation was investigated by allele specific duplex/multiplex-PCR on genomic DNA extracted from peripheral blood. Results: A total of 231 patients (age range: 26-77 years), 130 with a family history and 101 without were screened. The two founder mutations 185delAG in BRCA1 and 6174delT in BRCA2 were not found in any of the subjects. This was confirmed by molecular analysis. Conclusions: Our findings suggest that these BRCA mutations may not have a strong recurrent effect on breast cancer among the eastern Indian population. The contribution of these founder mutations to breast cancer incidence is probably low and could be limited to specific subgroups. This may be particularly useful in establishing further pre-screening strategies.

Electromagnetic Interference Reflectivity of Nanostructured Manganese Ferrite Reinforced Polypyrrole Composites

Chakraborty, Himel,Chabri, Sumit,Bhowmik, Nandagopal The Korean Institute of Electrical and Electronic 2013 Transactions on Electrical and Electronic Material Vol.14 No.6

Nano-size manganese ferrite reinforced conductive polypyrrole composites reveal a core-shell structure by in situ polymerization, in the presence of dodecyl benzene sulfonic acid as the surfactant and dopant, and iron chloride as the oxidant. The structure and magnetic properties of manganese ferrite nano-fillers were measured, by using X-ray diffraction and vibrating sample magnetometer. The morphology, microstructure, and conductivity of the composite were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, and four-wire technique. The microwave-absorbing properties of composites reinforcement dispersed in resin coating with the coating thickness of 1.2 nm were investigated, by using vector network analyzers, in the frequency range of 8~12 GHz. A reflection loss of -8 dB was observed at 10.5 GHz.

SOME RESULTS ON THE UNIQUE RANGE SETS

Chakraborty, Bikash,Kamila, Jayanta,Pal, Amit Kumar,Saha, Sudip Korean Mathematical Society 2021 대한수학회지 Vol.58 No.3

In this paper, we exhibit the equivalence between different notions of unique range sets, namely, unique range sets, weighted unique range sets and weak-weighted unique range sets under certain conditions. Also, we present some uniqueness theorems which show how two meromorphic functions are uniquely determined by their two finite shared sets. Moreover, in the last section, we make some observations that help us to construct other new classes of unique range sets.

Some pharmacological findings of non therapeutic importance of an Ayurvedic preparation Chandanasav

Chakraborty, Sharmila,Rajia, Sultana,Choudhuri, M. Shahabuddin Kabir,Hossain, M. Faruk,Sattar, Mafruhi,Shrestha, Tripti Kyung Hee Oriental Medicine Research Center 2006 Oriental pharmacy and experimental medicine Vol.6 No.2

Chandanasav is an Ayurvedic preparation slightly reduced the gastrointestinal motility at the 15 min time interval. It increased the latent period of castor oil induced diarrhoea, slightly decreased number of stool count and lowered the purging index values. Chandanasav significantly reduced the onset and increased the duration of pentobarbital induced sleeping time. No significant analgesic effect was observed from the hot plate study Thus it may have mild constipating and central nervous system depressant activity without any effect on peripheral nervous system.