Sensing metrics of a dual-cavity single-gate MOSHEMT

Dastidar Ananya,Patra Tapas Kumar,Mohapatra Sushanta Kumar,Braim Mona,Alodhayb Abdullah N. 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.6

This paper presents the simulation study of the impact of dielectric modulation on the characteristics of a single-gate singlecavity and a single-gate dual-cavity AlGaN/GaN heterostructure for biomolecule detection. The drain current, which is used as a sensing metric to carry out the device’s sensitivity analysis, is afected by dependent variables, such as cavity design, various biomolecules, and charges. The drain current sensitivity with HfO2 as the gate dielectric has been found to be 0.22 for cavity length of 40 nm each which decreased by 23% and 41% when cavity lengths are 30 nm and 25 nm, respectively. For 75%, 50%, and 25% fll percentage, the drain current sensitivity is observed to be 3.19, 0.75, and 0.54, respectively, establishing the applicability of the device for biosensing applications.

Debt Financing with Limited Liability and Quantity Competion

Krishnendu Ghosh Dastidar 서울대학교 경제연구소 1999 Seoul journal of economics Vol.12 No.3

In this paper we extend some results of Brander and Lewis (1986). In particular, we show that their main theorem, as it is stated, is not true. We provide the correct and extended version of that result and also discuss how this approach can be used to probe into some well known Industrial Organisation results.

Income Distribution and Structural Transformation: Empirical Evidence from Developed and Developing Countries

Ananya G,Dastidar 서울대학교 경제연구소 2012 Seoul journal of economics Vol.25 No.1

The process of structural transformation forms the very basis of economic growth and development. This paper analyses the implications of alternate patterns of structural change for changes in the overall distribution of income within an economy. An empirical analysis is carried out based on evidence from seventy-eight developing and transition economies and developed countries. The estimated results from a fixed effects panel data model, indicate the existence of substantial differences as well as important similarities between developed and developing country experience with respect to structural change and associated changes in income inequality.

Bioremediation of Binary System of Reactive Red 120 Dye and Cr(III) Using Aspergillus tamari and Statistical Validation of Response

Arpita Ghosh,Manisha Ghosh Dastidar,T. R. Sreekrishnan,Pradipta Patra 한국대기환경학회 2019 Asian Journal of Atmospheric Environment (AJAE) Vol.13 No.4

The efficiency of Aspergillus tamarii (isolated from sludge of a textile industry) was investigated to remediate the synthetic solutions of reactive red 120 (RR120) dye and chromium(III) separately. Also, parallel studies were conducted on the bioremediation of binary system of chromium(III) and RR120 dye in different ratios. The study was conducted to find the potential of the A. tamarii for removing chromium(III) and color from solutions containing only chromium or only RR120 dye or both and the effect of RR120 and chromium on the growth of the strain were observed. Maximum dye removal 81 mg/L was observed from 100 mg/L RR120 dye solution at pH 5 up to 50 hours. Maximum chromium removal 88.3 mg/L was observed from 100 mg/L chromium (III) solution at pH 5 up to 50 hours. In previous studies, A. tamarii was used as a bioremediator for removing different chromium complex dyes. The removal of chromium(III) and color were compared from solutions of synthetic mixtures and chromium complex dyes. The response of bioremediation study was validated using multiple regression analysis.

In vitro and in vivo antidiarrhoeal activity of epigallocatechin 3-gallate: a major catechin isolated from indian green tea

Bandyopadhyay, Durba,Dutta, Pradeep Kumar,Dastidar, Sujata G,Chatterjee, Tapan Kumar Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.2

Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of $25\;{\mu}g/ml$ whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at $10\;{\mu}g/ml$ level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at $50\;{\mu}g/ml$ level of EGCG. Only four strains were inhibited at $100\;{\mu}g/ml$. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG ($500\;{\mu}g/ml$ and $1,000\;{\mu}g/ml$) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.

In vitro and in vivo antidiarrhoeal activity of epigallocatechin 3-gallate: amajor catechin isolated from indian green tea

Durba Bandyopadhyay,Pradeep Kumar Dutta,Sujata G Dastidar,Tapan Kumar Chatterjee 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.2

Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of 25 μg/ml whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at 10 μg/ml level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at 50 μg/ml level of EGCG. Only four strains were inhibited at 100 μg/ml. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG (500 μg/ ml and 1,000 μg/ml) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum. Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of 25 μg/ml whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at 10 μg/ml level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at 50 μg/ml level of EGCG. Only four strains were inhibited at 100 μg/ml. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG (500 μg/ ml and 1,000 μg/ml) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.

Comparative study on simultaneous leaching of nutrients during bioleaching of heavy metals from sewage sludge using indigenous iron and sulphur oxidising microorganisms

Pathak, A.,Singh, P.,Dhama, P.,Dastidar, M.G.,Kim, D.J.,Heyes, G. Maney Publishing 2014 Canadian metallurgical quarterly Vol.53 No.1

The present study investigated the changes in nutrient profile of sewage sludge during bioleaching in a batch mode of operation. The study identified the optimum bioleaching period at which maximum solubilisation of metals is achieved while maintaining the fertilising property of the bioleached sludge. The bioleaching experiments were performed using anaerobically digested sewage sludge by employing indigenous iron and sulphur oxidising microorganisms. The results showed that bioleaching using sulphur oxidising microorganisms is comparatively advantageous due to the higher solubilisation of heavy metals. However, despite its high potential in solubilisation of heavy metals from the sludge, the bioleaching process resulted in the undesirable dissolution/loss of sludge bound nutrients (nitrogen and phosphorus), thus making the sludge less attractive for land application as a fertiliser. After 16 days of bioleaching about 45% of the nitrogen and 34% of the phosphorus were leached from the sludge using indigenous iron oxidising microorganisms, whereas about 78% of the nitrogen and 56% of the phosphorus were leached using indigenous sulphur oxidising microorganisms. The findings indicated that the fertilising property of the sewage sludge can be maintained by conducting the process for a shorter duration of time (up to 10 days). The optimum bioleaching period was 10 days where about 85%Cu, 71%Ni, 91%Zn and 61%Cr were solubilised from the sludge while the loss of nitrogen and phosphorus was only 56 and 51% respectively, by using sulphur oxidising microorganisms. The heavy metals remaining in the bioleached sludge were mostly in the residual fraction ensuring the safe disposal of bioleached sludge for land application as a fertiliser.

Phytochemical isoflavones against diabetic foot bacteria

Mazumdar, Kaushiki,Dutta, Noton Kumar,Dastidar, Sujata G.,Motohashi, Noboru,Shirataki, Yoshiaki Kyung Hee Oriental Medicine Research Center 2004 Oriental pharmacy and experimental medicine Vol.4 No.4

Wound swabs and pus samples were collected from diabetic foot ulcers, and control pus samples from non-diabetic cases. In 144 diabetic cases screened, Pseudomonas aeruginosa was isolated from 78 cases, in which 10.59% of the isolates were multidrug resistant (MDR), whereas the 60 control cases were not MDR. The isolated bacteria were decreasingly resistant to 6 clinically administrated antimicrobics such as ceftazidime, gentamicin, ciprofloxacin, tobramycin, piperacillin and amikacin. Therefore, it is demanded that new and more effective antimicrobials of phytochemical origins are sought after. Among 11 isoflavones (YS11-YS21) isolated from Sophora and Euchresta (Leguminosae; pea plant family), 2 (YS19 and YS21) prominently exhibited the high antibacterial activity both in vitro and in vivo. By the preliminary results, the object of this paper is to evaluate the in vitro antibacterial effect of YS19 and YS21 on the clinically isolated bactera of Ps. Aeruginosa in hospitals. All the isolates were sensitive to YS19 and YS21 and for both, minimum inhibitory concentration (MIC) values ranged from $2\;to\;50\;{\mu}g/mL$. The $MIC_{90}$ values of YS19 and YS21 were $50\;{\mu}g/mL$. It is suggested that these isoflavones might consist a basis phytochemical prevention and therapy for diabetic foot infections caused by pseudomonads.

Assessment of antibacterial activity of the cardiovascular drug nifedipine

Pal, Tapas,Dutta, Noton Kumar,Mazumdar, Kaushiki,Dasgupta, Asish,L., Jeyaseeli,Dastidar, Sujata G. Kyung Hee Oriental Medicine Research Center 2006 Oriental pharmacy and experimental medicine Vol.6 No.2

The cardiovascular drug nifedipine exhibited significant in vitro and in vivo antibacterial activity against 331 strains of bacteria belonging to three Gram-positive and twelve Gram-negative genera. The minimum inhibitory concentration of the drug, as determined both by agar and broth dilution methods, was seen to range from $25\;-\;200\;{\mu}g/ml$ against most test bacteria, including several pathogenic ones, in the in vitro studies. Nifedipine was bacteriostatic in action. in vivo studies with this drug showed that it could offer statistically significant protection (P < 0.001) to mice challenged with a virulent bacterium. Therefore, nifedipine has the potential of an antibacterial agent, which may be developed after further pharmacological studies.

Anti-Salmonella activity of a flavonone from Butea frondosa bark in mice

Mishra, Uma Shankar,Dutta, Noton Kumar,Mazumdar, Kaushiki,Mahapatra, Santosh Kumar,Chakraborty, Pronobesh,Dastidar, Sujata G Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.4

Butea frondosa has been used traditionally as a topical formulation in the treatment of many diseases and disorders. Two compounds [BF-1 (crystalline flavonol quercetin) and BF-2 (tannin) from ethyl acetate fraction of ethanolic extract] were isolated from the bark of Butea frondosa. The stereostructures of the compounds were determined on the basis of chemical and physicochemical evidence. BF-1 and BF-2 were screened in vitro for possible antibacterial property against 112 bacteria comprising 3 genera of Gram-positive and 12 genera of Gram-negative types. It was found that both BF-1 and BF-2 exhibited inhibitory activity against several bacteria. Most of these strains were inhibited by BF-1 at $50-200\;{\mu}g/ml$, while BF-2 ($MIC_{50}$ $400\;{\mu}g/ml$) was much less active. The bacteria could be arranged in the decreasing order of sensitivity towards BF-1 in the following manner: S. aureus, Bacillus spp., Salmonella spp., Vibrio spp., Shigella spp., E. coli and Pseudomonas spp. The $MIC_{50}$ of the compound was $50\;{\mu}g/ml$ while the $MIC_{90}$ was $100\;{\mu}g/ml$. The decreasing order of sensitivity towards BF-2 was V. cholerae, Bacillus spp., S. aureus, V. parahaemolyticus, Salmonella spp. and Proteus spp. BF-1 was bactericidal in action. In vivo studies with this extract showed that it could offer statistically significant protection (p < 0.01) to mice challenged with a virulent bacterium. The inhibitory activity of Butea frondosa against Gram-positive and Gram-negative bacteria indicates its usefulness in the treatment of common bacterial infections. The potentiality of BF-1 as an antibacterial agent may be confirmed further by pharmacological studies.