Organic photodetectors: Role of multiple donor-acceptor interfaces

Satyajit Sahu,Amlan J. Pal 한국물리학회 2007 Current Applied Physics Vol.7 No.2

We have fabricated photodetectors based on electronaccepting and electron-donating organic materials. Multiple heterojunctionsular scale. By keeping the total thickness of the devices the same, we have studied the performance of the photodetectors as a function ofthe number of such molecular-level interfaces. The results showed that the number of donoracceptor interfaces enhanced exciton dis-sociation but, at the same time, hindered charge transport by introducing energy barriers. We have shown that a trade-o between thetwo eects existed at an optimum number of donoracceptor interfaces, where the device showed better photodetector performance.

Effect of Citrus aurantium var amara on weight change in mice

Satyajit Dey Sarker,Bohlol Habibi,Tohid Sharifi,Solmaz Asnaashari,Lutfun Nahar,Abbas Delazar 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.3

Citrus aurantium var. amara L., commonly known as ‘bitter orange’ or ‘sour orange’, of the family Rutaceae, has traditionally been used in the treatment of various ailments, and it possesses different types of pharmacological properties. As a part of our on-going studies on the plants from the Iranian flora, the extract of C. aurantium var. amara has been studied for its weight loss properties using the mice model. While the Sep-Pak fraction, 20% methanol (MeOH) in water, of the hydro-methanolic extract of the peels of C. aurantium var. amara fruits, when injected intraperitoneal (i.p.) at a dose of 10 mg/kg, significantly decreased the level of weight gain of the mice in comparison with control the group (P < 0.01), the Sep-Pak fraction 80% MeOH in water decreased the initial weight of mice by 0.44% in six weeks. The administration of the total extract (10 and 20 mg/kg, i.p.), and the Sep-Pak fractions, 40% and 60% MeOH in water (10 mg/kg, i.p.) did not show any significant change of weight of the test mice. Of the two active fractions, the 80% MeOH in water fraction did not show any noticeable adverse effects on mice, and was therefore analysed by reversed-phase preparative high performance liquid chromatography resulting in the isolation and identification of four major components, two coumarins, meranzin hydrate (1) and bergamottin (2), and two flavonoids, xanthomicrol 5,4’-di-methyl ether (tangeritin, 3) and hymenoxin 5,7-di-methyl ether (nobiletin, 4). Citrus aurantium var. amara L., commonly known as ‘bitter orange’ or ‘sour orange’, of the family Rutaceae, has traditionally been used in the treatment of various ailments, and it possesses different types of pharmacological properties. As a part of our on-going studies on the plants from the Iranian flora, the extract of C. aurantium var. amara has been studied for its weight loss properties using the mice model. While the Sep-Pak fraction, 20% methanol (MeOH) in water, of the hydro-methanolic extract of the peels of C. aurantium var. amara fruits, when injected intraperitoneal (i.p.) at a dose of 10 mg/kg, significantly decreased the level of weight gain of the mice in comparison with control the group (P < 0.01), the Sep-Pak fraction 80% MeOH in water decreased the initial weight of mice by 0.44% in six weeks. The administration of the total extract (10 and 20 mg/kg, i.p.), and the Sep-Pak fractions, 40% and 60% MeOH in water (10 mg/kg, i.p.) did not show any significant change of weight of the test mice. Of the two active fractions, the 80% MeOH in water fraction did not show any noticeable adverse effects on mice, and was therefore analysed by reversed-phase preparative high performance liquid chromatography resulting in the isolation and identification of four major components, two coumarins, meranzin hydrate (1) and bergamottin (2), and two flavonoids, xanthomicrol 5,4’-di-methyl ether (tangeritin, 3) and hymenoxin 5,7-di-methyl ether (nobiletin, 4).

Extracts of Centaurea bornmuelleri and Centaurea huber-morathii inhibit the growth of coloncancer cells in vitro

Satyajit Dey Sarker,,Mohammad Shoeb,,Sezgin Celik,Marcel Jaspars,,Lutfun Nahar,,Paul Kong-Thoo-Lin,Stephen M MacManus 경희대학교 융합한의과학연구소 2007 Oriental Pharmacy and Experimental Medicine Vol.7 No.4

Plants from the genus Centaurea (C.) (Family: Asteraceae alt. Compositae), widely distributed in Asia, Europe and North America, have traditionally been used in the treatment of various ailments. As a part of our on-going studies on the plants from the genus C. for their phytochemistry and biological activities, extracts of the seeds of Turkish endemic C. species, C. bornmuelleri and C. huber-morathii, were tested for their cytotoxicity towards the CaCo2 colon cancer cell line as well as for the toxicity towards the brine shrimps, using the MTT and the brine shrimp lethality assays, respectively. Among the extracts, the MeOH extract of these plants showed significant toxicity towards the brine shrimps (LD50 = 55.2×10-2 and 42.4×10-2 mg/ml, respectively). The MeOH extract of both C. species also inhibited the growth of CaCo2 colon cancer cells in the MTT assay (IC50 = 29.9 and 33.0 g/ml, respectively). As the most prominent activities in both assays were observed with the MeOH extracts, it can be assumed that the compound(s) responsible for these activities are polar in nature.

Computer-Interfaced Blpolar Pulse Conductivlty Detector for Capollary Systems

Satyajit Kar,Purnendu K. Dasgupta,Hanghui Liu,Hoon, Hwang 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

Identifying the Critical Risk Factors for Road Crashes based on Large-Scale Safety Audits in India

Satyajit Mondal,Ashutosh Pandey,Ankit Gupta,Agnivesh Pani 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.11

Road transportation is considered one of the most essential factors for the growth of a country. Due to the exponential growth in population and fast urbanization, the existing roadway facilities are facing a huge surge in vehicle growth. But this development is also accompanied by the concerning growth of road crashes. To mitigate road crashes, one needs to identify the potential risk factors involved with them. This requires detailed accident data, which is sometimes difficult to acquire and in addition, there is a high probability of accidents in many places due to various hazardous situations, but there may not be an accident record yet. Road Safety Audit is an alternative approach that can overcome these obstacles. Hence, the present study has attempted to highlight various risk factors involved with road crashes for four different road facilities type, viz. Straight, intersection, curve, and road with culvert and flyovers (RCF) by conducting the Road Safety Audit for 216 black spots. Analytic Hierarchy Process (AHP) was performed on the data collected from the audit process to determine the weightage of involvement of each factor in road crashes and identify the most significant ones.

In Vitro Propagation of Trichosanthus Dioica Roxb. for Nutritional Security

Satyajit Saurabh,Dinesh Prasad,Ambarish S. Vidyarthi 한국작물학회 2017 Journal of crop science and biotechnology Vol.20 No.2

The pointed gourd (Trichosanthes dioica Roxb.) is an important cucurbit reported for its medicinal value, therapeutic potential, and as a popular delicacy (especially in Indian cuisine). Being nutritive and desirous, it has potential to feed the nations and addresses their nutritional security and economic prosperity. The plant is usually vegetatively propagated and cultivated for fruits during summer and rainy seasons. The limited supply of planting material, limits cultivation and production. The present study was in anticipation for direct organogenesis, callus induction, and somatic embryo formation from leaf and node explants of T. dioica Roxb. In this study, the MS medium supplemented with 0.5 mg/L BA and 0.5 mg/L 2,4-D was found to be most efficient for callus induction, followed by 0.5 mg/L Kn and 0.5 mg/L 2,4-D. The embryogenic callus was developed by sub-culturing of node callus in the same media. The scanning electron microscopic (SEM) analysis revealed the presence of embryogenic cell clusters having globular embryos, which were found irresponsive to develop further. Through direct organogenesis, the node explants have responded to produce true-to-type plants for propagation. It was observed that MS supplemented with 1.0 mg/L BA was efficient for shoot proliferation, and 0.5 mg/L IAA was found more efficient for root development. Notably, the plant remains unexplored in its potential for improvement involving molecular breeding and tissue culture. These results may be effective to produce genetically stable plants on a large scale and aid the genetic improvement of pointed gourds.

Higher Prevalence of Metabolic Syndrome in Child-adolescent Patients with Bipolar Disorder

Satyajit Mohite,Hanjing Wu,Shiva Sharma,Luca Lavagnino,Cristian P. Zeni,Terrence T. Currie,Jair C. Soares,Teresa A. Pigott 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.2

Objective: Previous studies have indicated a convergent and bidirectional relationship between metabolic syndrome (MetS) and bipolar disorder (BD). As most of these studies focused mainly on adults diagnosed with BD, our study aims to investigate and characterize metabolic disturbances in child-adolescents diagnosed with BD. Methods: We retrospectively examined the medical records of psychiatric hospitalizations with admitting diagnosis of BD in child-adolescents (age < 18 years). Body mass index (BMI), lipid profile, fasting blood glucose, and blood pressure were primary variables. National Cholesterol Education Program criteria were used to define MetS. Reference group data was obtained from the National Health and Nutrition Examination Survey study. Statistical analyses included t tests, chi-square tests, and Fisher’s exact tests. Results: We identified 140 child-adolescent patients with BD (mean age = 15.12 ± 1.70 years, 53% male). MetS was significantly more common in BD compared to the reference group: 14% (95% confidence interval [95% CI] 8−20) vs. 6.7% (95% CI 4.1−9.2), p = 0.001 with no significant difference by sex. MetS components were higher in the BD group, particularly BMI ≥ 95% (25% vs. 11.8%, p < 0.001) and high blood pressure (17% vs. 8%, p = 0.05). Moreover, female patients had lower odds of high blood pressure (odds ratio = 0.24 [95% CI 0.08−0.69], p = 0.005). Conclusion: Compared with the general child-adolescent population, the prevalence of MetS was significantly higher in patients with BD of same age. This reiterates the notion of an increased risk of MetS in patients diagnosed with BD; and thus, further exploration is warranted.

Bankruptcy and Unemployment in Optimal Wage Employment Contracts

Ghosh Satyajit 서울대학교 경제연구소 1989 Seoul journal of economics Vol.2 No.2

Optimal wage employment contracts under asymmetric information have shown that, if the firm is risk neutral and has the informational advantage over the risk averse workers, the second best contract prescribes underemployment if and only if the workers view leisure as an inferior good, and overemployment if and only if leisure is a normal good. In this paper it is shown that if leisure is a normal good and that if the firm wants to avoid bankruptcy, the optimal layoff contract, with optimal severance payment, may prescribe unemployment. A stronger unemployment result is obtained in the absence of severance pay. Finally, it is shown that, if the contracts specify both the working hours and the number of empolyed workers, the optimal contract may exhibit unemployment with respect to both the number of workers and the working hours, provided few technological preconditions are satisfied.

Extracts of Centaurea bornmuelleri and Centaurea huber-morathii inhibit the growth of colon cancer cells in vitro

Sarker, Satyajit Dey,Shoeb, Mohammad,Celik, Sezgin,Jaspars, Marcel,Nahar, Lutfun,Kong-Thoo-Lin, Paul,MacManus, Stephen M Kyung Hee Oriental Medicine Research Center 2007 Oriental pharmacy and experimental medicine Vol.7 No.4

Plants from the genus Centaurea (C.) (Family: Asteraceae alt. Compositae), widely distributed in Asia, Europe and North America, have traditionally been used in the treatment of various ailments. As a part of our on-going studies on the plants from the genus C. for their phytochemistry and biological activities, extracts of the seeds of Turkish endemic C. species, C. bornmuelleri and C. huber-morathii, were tested for their cytotoxicity towards the CaCo2 colon cancer cell line as well as for the toxicity towards the brine shrimps, using the MTT and the brine shrimp lethality assays, respectively. Among the extracts, the MeOH extract of these plants showed significant toxicity towards the brine shrimps ($LD_{50}=55.2{\times}10^{-2}\;and\;42.4{\times}10^{-2}mg/ml$, respectively). The MeOH extract of both C. species also inhibited the growth of CaCo2 colon cancer cells in the MTT assay ($IC_{50}$=29.9 and 33.0 g/ml, respectively). As the most prominent activities in both assays were observed with the MeOH extracts, it can be assumed that the compound(s) responsible for these activities are polar in nature.

Evaluation of Antitumor and Antioxidant Activity of Sargassum tenerrimum against Ehrlich Ascites Carcinoma in Mice

Patra, Satyajit,Muthuraman, Meenakshi Sundaram,Prabhu, A.T.J. Ram,Priyadharshini, R. Ramya,Parthiban, Sujitha Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

Context: In the last half century, discovering, developing and introducing of clinical agents from marine sources have seen great successes, with examples including the anti-cancer compound trabectedin. However, with increasing need for new anticancer drugs, further exploration for novel compounds from marine organism sources is strongly justified. Objective: The major aim of this study was to evaluate the antitumor and antioxidant potential of Sargassum tenerrimum J.Agardh (Sargassaceae) on Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Materials and Methods: An ethanol extract of S. tenerrimum (EEST) from whole algae was used to evaluate cytotoxicity followed by in vivo assessment of toxicity, using biochemical parameters including hepatic and non-hepatic enzymes. Antioxidant properties were examined in animals bearing EAC treated with daily oral administration of 100-300 mg/kg extract suspension. Results: Antitumor effects of EEST in EAC bearing mice was observed with LD50 1815 mg/kg. Parameters like body weight, tumor volume, packed cell volume, tumor cell count, mean survival time and increase in life span in animals in the EAC bearing animals treated with EEST 300 mg/kg was comparable with control group. Significant differences were also seen with changes in total protein content, hepatic enzymes contents, MDA level, and free radical scavenging enzymes in untreated vs. EEST treated group animals. Conclusions: Evaluation of antioxidant enzymes and hepatic enzymes in the EAC animal model treated with EEST exhibited similar effects as the positive control drug 5-flurouracil. S. tenerrimum extracts contain effective antioxidants with significant antitumor activity.