Qualitative analysis of growth mechanism of polycrystalline InAs thin films grown by molecular beam epitaxy

Agrawal, Arpana,Tchoe, Youngbin,Kim, Heehun,Park, Joon Young Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.462 No.-

<P><B>Abstract</B></P> <P>The mechanism of surfaces/interfaces and precise control of growth morphology is a key parameter for any specific device application. Herein, we report on a qualitative growth study of molecular beam epitaxy-grown polycrystalline InAs thin films on a lattice-mismatched Si(1 0 0) substrate using atomic force microscopy. The height-height correlation function (HHCF) and power spectral density function (PSDF) were employed to analyze the surface structures. Clear oscillatory behavior in the HHCF for sufficiently larger lateral distances suggests a mound-like morphology, which was confirmed by the existence of a characteristic frequency peak in the PSDF. The growth mechanism is described qualitatively by the Schwoebel barrier (roughening) effect coupled with the Mullins diffusion model (smoothing effect).</P> <P><B>Highlights</B></P> <P> <UL> <LI> HHCF and PSDF were employed to analyze the surface structures. </LI> <LI> Oscillatory behavior in HHCF for larger lateral distances suggests mound-like morphology. </LI> <LI> Existence of characteristic frequency peak in the PSDF further supports mound-like structure. </LI> <LI> Growth mechanism is well explained by the Schwoebel barrier effect coupled with the Mullins diffusion model. </LI> </UL> </P>

Physicochemical and pharmacokinetic evaluation of rosuvastatin loaded nanostructured lipid carriers: influence of long- and medium-chain fatty acid mixture

Varsha Pokharkar,Arpana Patil‑Gadhe,Gursheen Kaur 한국약제학회 2018 Journal of Pharmaceutical Investigation Vol.48 No.4

Combination of long and medium chain lipids show different behavior in-vivo and contribute differently for bioavailability. Aim of the present study was to evaluate the effect of long chain- (LCFA) and medium-chain (MCFA) fatty acid lipids on the bioavailability of rosuvastatin from rosuvastatin loaded nanostructured lipid carrier (RNLC). Lauric acid and capryol-90™ were selected as MCFA whereas stearic acid and oleic acid were chosen as LCFA. RNLC was prepared using melt-emulsification– ultrasonication method using different combinations of MCFA and LCFA. Non-ionic, non-toxic MYS-25 was used as stabilizing agent. RNLC showed entrapment efficiency of 85–92% denoting it to be beneficial for prolonged release of drug after oral administration. Zeta potential of −26.79 mV signifies particle stability through the repulsive forces which prevents aggregation upon storage. In-vivo oral pharmacokinetic study demonstrated six to ninefold improvement in the bioavailability of rosuvastatin (RSVS) in the form of RNLC than RSVS-Aqueous dispersion. A 1.5-fold increase in bioavailability was observed when RNLC was prepared with LCFA solid lipid and MCFA liquid lipid combination as compared to RNLC prepared using only MCFA as both solid and liquid lipid. Use of LCFA and MCFA combination was found to be superior as lipid mixture for the RNLC.

Consequences of Water Induced Disasters to Livelihood Activities in Nepal

( Anup Gurung ),( Arpana Karki ),( Rahul Karki ),( Rajesh Bista ),( Sang Eun Oh ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.2

BACKGROUND: The changes in the climatic conditions have brought potentially significant new challenges, most critical are likely to be its impact on local livelihoods, agriculture, biodiversity and environments. Water induced disasters such as landslides, floods, erratic rain etc., are very common in developing countries which lead to changes in biological, geophysical and socioeconomic elements. The extent of damages caused by natural disasters is more sever in least developing countries. However, disasters affect women and men differently. In most of the cases women have to carry more burden as compared to their male counterpart during the period of disasters, METHODS AND RESULTS: This study examines the impact of disasters on the local livelihood especially agriculture and income generating activities of women in three districts of Nepal. The study uses the primary data collected following an exploratory approach, based on an intensive field study. The general findings of the study revealed that women had to experience hard time as compared to their male counterpart both during and after the disaster happen. Women are responsible for caring their children, collecting firewood, fetching water, collecting grass for livestock and performing household chores. Whereas, men are mainly involved in out-migration and remained out-side home most of the time. After the disaster occurred, most of the women had to struggle to support their lives as well as had to work longer hours than men during reconstruction period. Nepal follows patriarchal system and men can afford more leisure time as compared to women. During the disaster period, some of the households lost their agricultural lands, livestock and other properties. These losses created some additional workload to women respondent, however at the same time; they learn to build confidence, self-respect, self-esteem, and self-dependency. Although Nepal is predominantly agriculture, majority of the farmers are at subsistence level. In addition, men and women have different roles which differ with the variation in agro-production systems. Moreover women are extensively involved in agricultural activities though their importances were not recognized. Denial of land ownership and denial of access to resources as well as migration of male counterparts are some of the major reasons for affecting the agricultural environments for women in Nepal. CONCLUSION: The shelter reconstruction program has definitely brought positive change in women`s access to decision making. The gradual increase in number of women respondent in access to decision making in different areas is a positive change and this has also provided them with a unique opportunity to change their gendered status in society. Furthermore, the exodus out-flow of male counterparts accelerated the additional burden and workload on women.

Valence and conduction band offset measurements in Ni0.07Zn0.93O/ZnO heterostructure

Tanveer Ahmad Dar,Arpana Agrawal,Pankaj Misra,Lalit M. Kukreja,Pranay Kumar Sen,Pratima Sen 한국물리학회 2014 Current Applied Physics Vol.14 No.2

We report valence and conduction band offset measurements in a pulsed laser deposited Ni0.07Zn0.93O/ ZnO heterostructure using X-ray photoelectron spectroscopy, valence band spectroscopy and ultraviolet visible spectroscopy. Neglecting the strain effect, the valence band offset was estimated to be 0.32 eV and the conduction band offset comes out to be 0.23 eV. Ratio between conduction band and valence band offset is 0.72. Core level shifting due to Ni doping has also been explained. Magnetotransport study of Ni0.07Zn0.93O film reveals that the charge carriers might be spin polarized at the interface of the heterojunction.

Consequences of Water Induced Disasters to Livelihood Activities in Nepal

Gurung, Anup,Karki, Arpana,Karki, Rahul,Bista, Rajesh,Oh, Sang-Eun The Korean Society of Environmental Agriculture 2012 한국환경농학회지 Vol.31 No.2

BACKGROUND: The changes in the climatic conditions have brought potentially significant new challenges, most critical are likely to be its impact on local livelihoods, agriculture, biodiversity and environments. Water induced disasters such as landslides, floods, erratic rain etc., are very common in developing countries which lead to changes in biological, geophysical and socioeconomic elements. The extent of damages caused by natural disasters is more sever in least developing countries. However, disasters affect women and men differently. In most of the cases women have to carry more burden as compared to their male counterpart during the period of disasters. METHODS AND RESULTS: This study examines the impact of disasters on the local livelihood especially agriculture and income generating activities of women in three districts of Nepal. The study uses the primary data collected following an exploratory approach, based on an intensive field study. The general findings of the study revealed that women had to experience hard time as compared to their male counterpart both during and after the disaster happen. Women are responsible for caring their children, collecting firewood, fetching water, collecting grass for livestock and performing household chores. Whereas, men are mainly involved in out-migration and remained out-side home most of the time. After the disaster occurred, most of the women had to struggle to support their lives as well as had to work longer hours than men during reconstruction period. Nepal follows patriarchal system and men can afford more leisure time as compared to women. During the disaster period, some of the households lost their agricultural lands, livestock and other properties. These losses created some additional workload to women respondent, however at the same time; they learn to build confidence, self-respect, self-esteem, and self-dependency.Although Nepal is predominantly agriculture, majority of the farmers are at subsistence level. In addition, men and women have different roles which differ with the variation in agro-production systems. Moreover women are extensively involved in agricultural activities though their importances were not recognized. Denial of land ownership and denial of access to resources as well as migration of male counterparts are some of the major reasons for affecting the agricultural environments for women in Nepal. CONCLUSION: The shelter reconstruction program has definitely brought positive change in women's access to decision making. The gradual increase in number of women respondent in access to decision making in different areas is a positive change and this has also provided them with a unique opportunity to change their gendered status in society.Furthermore, the exodus out-flow of male counterparts accelerated the additional burden and workload on women.

Increased Cellular NAD+ Level through NQO1 Enzymatic Action Has Protective Effects on Bleomycin-Induced Lung Fibrosis in Mice

오기수,이수빈,Anjani Karna,김형진,AiHua Shen,Arpana Pandit,이승훈,양세훈,소홍섭 대한결핵및호흡기학회 2016 Tuberculosis and Respiratory Diseases Vol.79 No.4

Background: Idiopathic pulmonary fibrosis is a common interstitial lung disease; it is a chronic, progressive, and fatal lung disease of unknown etiology. Over the last two decades, knowledge about the underlying mechanisms of pulmonary fibrosis has improved markedly and facilitated the identification of potential targets for novel therapies. However, despite the large number of antifibrotic drugs being described in experimental pre-clinical studies, the translation of these findings into clinical practices has not been accomplished yet. NADH:quinone oxidoreductase 1 (NQO1) is a homodimeric enzyme that catalyzes the oxidation of NADH to NAD+ by various quinones and thereby elevates the intracellular NAD+ levels. In this study, we examined the effect of increase in cellular NAD+ levels on bleomycin-induced lung fibrosis in mice. Methods: C57BL/6 mice were treated with intratracheal instillation of bleomycin. The mice were orally administered with β-lapachone from 3 days before exposure to bleomycin to 1-3 weeks after exposure to bleomycin. Bronchoalveolar lavage fluid (BALF) was collected for analyzing the infiltration of immune cells. In vitro, A549 cells were treated with transforming growth factor β1 (TGF-β1) and β-lapachone to analyze the extracellular matrix (ECM) and epithelialmesenchymal transition (EMT). Results: β-Lapachone strongly attenuated bleomycin-induced lung inflammation and fibrosis, characterized by histological staining, infiltrated immune cells in BALF, inflammatory cytokines, fibrotic score, and TGF-β1, α-smooth muscle actin accumulation. In addition, β-lapachone showed a protective role in TGF-β1–induced ECM expression and EMT in A549 cells. Conclusion: Our results suggest that β-lapachone can protect against bleomycin-induced lung inflammation and fibrosis in mice and TGF-β1–induced EMT in vitro, by elevating the NAD+/NADH ratio through NQO1 activation.

Molecular fossils “pseudogenes” as functional signature in biological system

Rajesh Kumar Singh,Divya Singh,Arpana Yadava,Akhileshwar Kumar Srivastava 한국유전학회 2020 Genes & Genomics Vol.42 No.6

Pseudogenes have been known as non-functional molecular relics developed from inactivated genomic mutations while evolution. However, they have a various function at distinct molecular stages (DNA, RNA and protein) in different biological events including in cancer and associated with parental-gene-dependently and parental-gene independently. The interactions of pseudogenes with ancestor genes or other genes alter in their sequences and transcriptional processes. Pseudogene of RNA sequences have multiple functions in post-transcriptional activities as antisense RNAs, endogenous small-interference RNAs, and competing endogenous RNAs. Moreover, it also plays vital roles in controlling of its parent genes and other pseudogenes transcribing into RNA. Pseudogene transcripts make small interfering RNA or decline cellular miRNA level. The current review focuses on pseudogene functional signature in human genome by regulating the gene expression.

Review : Cisplatin-induced Kidney Dysfunction and Perspectives on Improving Treatment Strategies

( Gi Su Oh ),( Hyung Jin Kim ),( Ai Hua Shen ),( Su Bin Lee ),( Dipendra Khadka ),( Arpana Pandit ),( Hong Seob So ) 대한전해질학회 2014 Electrolytes & Blood Pressure Vol.12 No.2

Cisplatin is one of the most widely used and highly effective drug for the treatment of various solid tumors; however, it has dose-dependent side effects on the kidney, cochlear, and nerves. Nephrotoxicity is the most well-known and clinically important toxicity. Numerous studies have demonstrated that several mechanisms, including oxidative stress, DNA damage, and inflammatory res-ponses, are closely associated with cisplatin-induced nephrotoxicity. Even though the establishment of cisplatin-induced nephrotoxicity can be alleviated by diuretics and pre-hydration of patients, the prevalence of cisplatin nephrotoxi- city is still high, occurring in approximately one-third of patients who have under- gone cisplatin therapy. Therefore it is imperative to develop treatments that will ameliorate cisplatin-nephrotoxicity. In this review, we discuss the mechanisms of cisplatin-induced renal toxicity and the new strategies for protecting the kidneys from the toxic effects without lowering the tumoricidal activity.

Increased Cellular NAD⁺ Level through NQO1 Enzymatic Action Has Protective Effects on Bleomycin-Induced Lung Fibrosis in Mice

Oh, Gi-Su,Lee, Su-Bin,Karna, Anjani,Kim, Hyung-Jin,Shen, AiHua,Pandit, Arpana,Lee, SeungHoon,Yang, Sei-Hoon,So, Hong-Seob The Korean Academy of Tuberculosis and Respiratory 2016 Tuberculosis and Respiratory Diseases Vol.79 No.4

Background: Idiopathic pulmonary fibrosis is a common interstitial lung disease; it is a chronic, progressive, and fatal lung disease of unknown etiology. Over the last two decades, knowledge about the underlying mechanisms of pulmonary fibrosis has improved markedly and facilitated the identification of potential targets for novel therapies. However, despite the large number of antifibrotic drugs being described in experimental pre-clinical studies, the translation of these findings into clinical practices has not been accomplished yet. NADH:quinone oxidoreductase 1 (NQO1) is a homodimeric enzyme that catalyzes the oxidation of NADH to $NAD^+$ by various quinones and thereby elevates the intracellular $NAD^+$ levels. In this study, we examined the effect of increase in cellular $NAD^+$ levels on bleomycin-induced lung fibrosis in mice. Methods: C57BL/6 mice were treated with intratracheal instillation of bleomycin. The mice were orally administered with ${\beta}$-lapachone from 3 days before exposure to bleomycin to 1-3 weeks after exposure to bleomycin. Bronchoalveolar lavage fluid (BALF) was collected for analyzing the infiltration of immune cells. In vitro, A549 cells were treated with transforming growth factor ${\beta}1$ (TGF-${\beta}1$) and ${\beta}$-lapachone to analyze the extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT). Results: ${\beta}$-Lapachone strongly attenuated bleomycin-induced lung inflammation and fibrosis, characterized by histological staining, infiltrated immune cells in BALF, inflammatory cytokines, fibrotic score, and TGF-${\beta}1$, ${\alpha}$-smooth muscle actin accumulation. In addition, ${\beta}$-lapachone showed a protective role in TGF-${\beta}1$-induced ECM expression and EMT in A549 cells. Conclusion: Our results suggest that ${\beta}$-lapachone can protect against bleomycin-induced lung inflammation and fibrosis in mice and TGF-${\beta}1$-induced EMT in vitro, by elevating the $NAD^+$/NADH ratio through NQO1 activation.

Increased Cellular NAD⁺ Level through NQO1 Enzymatic Action Has Protective Effects on Bleomycin-Induced Lung Fibrosis in Mice

( Gi-su Oh ),( Su-bin Lee ),( Anjani Karna ),( Hyung-jin Kim ),( Aihua Shen ),( Arpana Pandit ),( Seunghoon Lee ),( Sei-hoon Yang ),( Hong-seob So ) 대한결핵 및 호흡기학회 2016 Tuberculosis and Respiratory Diseases Vol.79 No.4

Background: Idiopathic pulmonary fibrosis is a common interstitial lung disease; it is a chronic, progressive, and fatal lung disease of unknown etiology. Over the last two decades, knowledge about the underlying mechanisms of pulmonary fibrosis has improved markedly and facilitated the identification of potential targets for novel therapies. However, despite the large number of antifibrotic drugs being described in experimental pre-clinical studies, the translation of these findings into clinical practices has not been accomplished yet. NADH:quinone oxidoreductase 1 (NQO1) is a homodimeric enzyme that catalyzes the oxidation of NADH to NAD⁺ by various quinones and thereby elevates the intracellular NAD+ levels. In this study, we examined the effect of increase in cellular NAD⁺ levels on bleomycin-induced lung fibrosis in mice. Methods: C57BL/6 mice were treated with intratracheal instillation of bleomycin. The mice were orally administered with モ-lapachone from 3 days before exposure to bleomycin to 1-3 weeks after exposure to bleomycin. Bronchoalveolar lavage fluid (BALF) was collected for analyzing the infiltration of immune cells. In vitro, A549 cells were treated with transforming growth factor β1 (TGF-β1) and モ-lapachone to analyze the extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT). Results: β-Lapachone strongly attenuated bleomycin-induced lung inflammation and fibrosis, characterized by histological staining, infiltrated immune cells in BALF, inflammatory cytokines, fibrotic score, and TGF-β1, α-smooth muscle actin accumulation. In addition, β-lapachone showed a protective role in TGF-β1-induced ECM expression and EMT in A549 cells. Conclusion: Our results suggest that β-lapachone can protect against bleomycin-induced lung inflammation and fibrosis in mice and TGF-β1-induced EMT in vitro, by elevating the NAD⁺/NADH ratio through NQO1 activation.