Molecular Dynamics of Carbon Nanotubes Deposited on a Silicon Surface via Collision: Temperature Dependence

Saha, Leton C.,Mian, Shabeer A.,Kim, Hyo-Jeong,Saha, Joyanta K.,Matin, Mohammad A.,Jang, Joon-Kyung Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

We investigated how temperature influences the structural and energetic dynamics of carbon nanotubes (CNTs) undergoing a high-speed impact with a Si (110) surface. By performing molecular dynamics simulations in the temperature range of 100 - 300 K, we found that a low temperature CNT ends up with a higher vibrational energy after collision than a high temperature CNT. The vibrational temperature of CNT increases by increasing the surface temperature. Overall, the structural and energy relaxation of low temperature CNTs are faster than those of high temperature CNTs.

Replacement Value of Two Bangladeshi Varieties of Yellow Corn for Wheat in the Diet of Laying Chicken

Saha, P.K.,Chowdhury, S.D.,Das, S.C.,Saha, S.K. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.5

Two Bangladeshi varieties of yellow corn-'Barnali' and 'Khaibhutta' were chemically analysed and used in the diet of laying chicken to determine their replacement value for wheat. Both the new varieties of yellow corn were found to be good sources of energy and the CP contents were comparable to wheat. Forty two, 29-week old randomly selected Starcross Brown commercial pullets were assigned to 7 dietary treatments with 6 replicates, each being an experimental unit. Diets were formulated replacing wheat quantitatively by two varieties of yellow corn either 0, 50, 75 or 100 per cent from a wheat based control diet. The production performance of laying hens fed diets formulated with Barnali or Khaibhutta at different dietary levels during an experimental period of 16 weeks was satisfactory and comparable to wheat based diet. Except egg yolk colour, the other internal arid external egg quality characteristics at 8th and 16th weeks of the experiment did not differ significantly. The egg yolk colour improved significantly (p<0.01) by feeding both the new varieties of corn and the degree of pigmentation of yolk increased as the dietary levels of corn increased at the expense of wheat. Considering laying performance, the new varieties of yellow corn, Barnali or Khaibhutta can be used in layer diet as replacement of wheat. Such a replacement would better that wheat-based diet in terms of egg yolk pigmentation.

Antiinflammatory Evaluation of Leucas lavandulaefolia Rees. Extract

Saha, Kakali,Mukherjee, Pulok K.,Das, J.,Mandal, Subhash C.,Saha, B.P.,Pal, M. The Korean Society of Pharmacognosy 1996 Natural Product Sciences Vol.2 No.2

The antiinflammatory activity of the methanol extract of Leucas lavandulaefolia Rees was evaluated on different experimental models of inflammation in rats. The extract has been found to possess significant, inhibitory activity against carrageenin, histamine, serotonin, and dextran induced hind paw oedema in rats. The effect produced by extract was comparable to that of phenylbutazone and a prototype, nonsteroidal antiinflammatory agent.

Habitat complexity reduces prey vulnerability: An experimental analysis using aquatic insect predators and immature dipteran prey

Nabaneeta Saha,Goutam K. Saha,Gautam Aditya 한국응용곤충학회 2009 Journal of Asia-Pacific Entomology Vol.12 No.4

The effects of alternative prey and structural complexity of habitat on the selection of mosquito larvae by aquatic insect predators were evaluated in the laboratory. The water bugs Anisops bouvieri, Diplonychus (=Sphaerodema) rusticus, and D. annulatus, and the odonate nymphs, Ceriagrion coromandelianum and Brachydiplax chalybea chalybea, selected mosquito larvae based on their abundance relative to chironomid larvae and on the levels of habitat complexity. The effect of one prey species on the other was asymmetrical, as indicated through prey selectivity values. Compared to open habitat, the presence of macrophytes reduced the vulnerability of mosquito larvae while the effect was reverse in the presence of sediments. When both sediment and macrophytes were present in habitats, all the predators except D. annulatus consumed more mosquito larvae than chironomid larvae. The clearance rate, an indicator of predatory efficiency, varied among the predator species and habitat types. The results suggest that the outcome of the interactions between insect predators and mosquito immatures was context-dependent and that it was mediated by the presence of alternative controphic species and the habitat complexity. The effects of alternative prey and structural complexity of habitat on the selection of mosquito larvae by aquatic insect predators were evaluated in the laboratory. The water bugs Anisops bouvieri, Diplonychus (=Sphaerodema) rusticus, and D. annulatus, and the odonate nymphs, Ceriagrion coromandelianum and Brachydiplax chalybea chalybea, selected mosquito larvae based on their abundance relative to chironomid larvae and on the levels of habitat complexity. The effect of one prey species on the other was asymmetrical, as indicated through prey selectivity values. Compared to open habitat, the presence of macrophytes reduced the vulnerability of mosquito larvae while the effect was reverse in the presence of sediments. When both sediment and macrophytes were present in habitats, all the predators except D. annulatus consumed more mosquito larvae than chironomid larvae. The clearance rate, an indicator of predatory efficiency, varied among the predator species and habitat types. The results suggest that the outcome of the interactions between insect predators and mosquito immatures was context-dependent and that it was mediated by the presence of alternative controphic species and the habitat complexity.

Molecular Dynamics of Carbon Nanotubes Deposited on a Silicon Surface via Collision: Temperature Dependence

Leton C. Saha,Shabeer A. Mian,김효정,Mohammad A. Matin,Joyanta K. Saha,장준경 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

We investigated how temperature influences the structural and energetic dynamics of carbon nanotubes (CNTs) undergoing a high-speed impact with a Si (110) surface. By performing molecular dynamics simulations in the temperature range of 100 - 300 K, we found that a low temperature CNT ends up with a higher vibrational energy after collision than a high temperature CNT. The vibrational temperature of CNT increases by increasing the surface temperature. Overall, the structural and energy relaxation of low temperature CNTs are faster than those of high temperature CNTs.

Prognostic role of EGR1 in breast cancer: a systematic review

( Subbroto Kumar Saha ),( S. M. Riazul Islam ),( Tripti Saha ),( Afsana Nishat ),( Polash Kumar Biswas ),( Minchan Gil ),( Lewis Nkenyereye ),( Shaker El-sappagh ),( Saiful Islam ),( Ssang-goo Cho ) 생화학분자생물학회 2021 BMB Reports Vol.54 No.10

EGR1 (early growth response 1) is dysregulated in many cancers and exhibits both tumor suppressor and promoter activities, making it an appealing target for cancer therapy. Here, we used a systematic multi-omics analysis to review the expression of EGR1 and its role in regulating clinical outcomes in breast cancer (BC). EGR1 expression, its promoter methylation, and protein expression pattern were assessed using various publicly available tools. COSMIC-based somatic mutations and cBioPortal-based copy number alterations were analyzed, and the prognostic roles of EGR1 in BC were determined using Prognoscan and Kaplan-Meier Plotter. We also used bc-GenEx-Miner to investigate the EGR1 co-expression profile. EGR1 was more often downregulated in BC tissues than in normal breast tissue, and its knockdown was positively correlated with poor survival. Low EGR1 expression levels were also associated with increased risk of ER+, PR+, and HER2- BCs. High positive correlations were observed among EGR1, DUSP1, FOS, FOSB, CYR61, and JUN mRNA expression in BC tissue. This systematic review suggested that EGR1 expression may serve as a prognostic marker for BC patients and that clinicopathological parameters influence its prognostic utility. In addition to EGR1, DUSP1, FOS, FOSB, CYR61, and JUN can jointly be considered prognostic indicators for BC. [BMB Reports 2021; 54(10): 497-504]

Micellar Catalysis on 1,10-Phenanthroline Promoted Chromic Acid Oxidation of Ethane-1,2-diol in Aqueous Media at Room Temperature

Ghosh, Sumanta K.,Saha, Rumpa,Ghosh, Aniruddha,Basu, Ankita,Mukherjee, Kakali,Saha, Indrajit,Saha, Bidyut Korean Chemical Society 2012 대한화학회지 Vol.56 No.6

Under pseudo-first order conditions, the monomeric species of Cr(VI) was found to be kinetically active in the absence of phenanthroline (phen) whereas in the phen-promoted path, the Cr(VI)-phen complex undergoes a nucleophilic attack by etane-1,2-diol to form a ternary complex which subsequently experience a redox decomposition leading to hydroxy ethanal and Cr(III)-phen complex. The effect of the cationic surfactant (CPC), anionic surfactant (SDS) and neutral surfactant (TX-100) on the unpromoted and phen-promoted path have been studied. Micellar effects have been explained by considering the preferential partitioning of reactants between the micellar and aqueous phase. Combination of TX-100 and phenanthroline will be the ideal for chromic acid oxidation of ethane-1,2-diol in aqueous media.

Highly Sensitive Bendable and Foldable Paper Sensors Based on Reduced Graphene Oxide

Saha, Biswajit,Baek, Sangwoong,Lee, Junghoon American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.5

<P>Over the past decade, the demand for high-performance wearable sensors has increased because of their capability for interaction with humans. Such sensors have typically been prepared on conventional substrates, such as silicon, PDMS, and copper mesh. In this work, we propose a class of wearable sensors fabricated from reduced graphene oxide (rGO) patterned paper substrates (rGO-paper). These rGO-paper sensors are highly sensitive to various deformations and capable of measuring bending and folding angles as small as 0.2 degrees and 0.1 degrees, respectively. We have demonstrated the applicability of these high-performance rGO-paper sensors by patterning rGO on kirigamis that can detect pulse and the motion of knees, wrists, and fingers. Finally, paper rings lined with rGO sensors were used to control a robotic hand, and an rGO-paper keyboard was used to light LEDs.</P>

Recent Advancements in Calix[4]pyrrole‐Based Anion‐Receptor Chemistry

Saha, Indrajit,Lee, Jeong Tae,Lee, Chang‐,Hee WILEY‐VCH Verlag 2015 EUROPEAN JOURNAL OF ORGANIC CHEMISTRY Vol.2015 No.18

<P><B>Abstract</B></P><P>Calix[4]pyrroles and their congeners are conformationally flexible, nonplanar tetrapyrrolic macrocycles that can recognize anionic substrates. Although the mother calix[4]pyrrole was reported more than 100 years ago, anion recognition accompanied with conformational changes was first discovered in 1996. These compounds have shown preferential binding of halide anions such as fluoride and chloride as well as that of phosphate and carboxylate anions. Extensive efforts have been made to improve the affinity and selectivity. Continuous expansion of related research makes this easy‐to‐make macrocycle more promising. In this review, recent synthetic developments and the anion binding properties of newly developed calix[4]pyrroles are discussed and accomplishments to date are summarized. We hope that this review provides a seed for future developments in this area of chemistry.</P>

Examining cooperative binding of Sox2 on DC5 regulatory element upon complex formation with Pax6 through excess electron transfer assay

Saha, Abhijit,Kizaki, Seiichiro,De, Debojyoti,Endo, Masayuki,Kim, Kyeong Kyu,Sugiyama, Hiroshi Oxford University Press 2016 Nucleic acids research Vol.44 No.14

<P>Functional cooperativity among transcription factors on regulatory genetic elements is pivotal for milestone decision-making in various cellular processes including mammalian development. However, their molecular interaction during the cooperative binding cannot be precisely understood due to lack of efficient tools for the analyses of protein–DNA interaction in the transcription complex. Here, we demonstrate that photoinduced excess electron transfer assay can be used for analysing cooperativity of proteins in transcription complex using cooperative binding of Pax6 to Sox2 on the regulatory DNA element (DC5 enhancer) as an example. In this assay, <SUP>Br</SUP>U-labelled DC5 was introduced for the efficient detection of transferred electrons from Sox2 and Pax6 to the DNA, and guanine base in the complementary strand was replaced with hypoxanthine (I) to block intra-strand electron transfer at the Sox2-binding site. By examining DNA cleavage occurred as a result of the electron transfer process, from tryptophan residues of Sox2 and Pax6 to DNA after irradiation at 280 nm, we not only confirmed their binding to DNA but also observed their increased occupancy on DC5 with respect to that of Sox2 and Pax6 alone as a result of their cooperative interaction.</P>