A BAYESIAN SDP MODEL FOR MULTI-RESERVOIR OPERATION

NIRMALA B,MUJUMDAR P.P 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Prospecting endophytic colonization in Waltheria indica for biosynthesis of silver nanoparticles and its antimicrobial activity

Nirmala, C.,Sridevi, M. Techno-Press 2022 Advances in nano research Vol.13 No.4

Endophytes ascertain a symbiotic relationship with plants as promoters of growth, defense mechanism etc. This study is a first report to screen the endophytic population in Waltheria indica, a tropical medicinal plant. 5 bacterial and 3 fungal strains in leaves, 3 bacterial and 1 yeast species in stems were differentiated morphologically and identified by biochemical and molecular methods. The phylogenetic tree of the isolated endophytes was constructed using MEGA X. Silver nanoparticles were biosynthesized from a rare endophytic bacterium Cupriavidus metallidurans isolated from the leaf of W. indica. The formation of silver nanoparticles was confirmed by UV-Visible spectrophotometer that evidenced a strong absorption band at 408.5 nm of UV-Visible range with crystalline nature and average particle size of 16.4 nm by Particle size analyzer. The Fourier Transform Infra-Red spectrum displayed the presence of various functional groups that stabilized the nanoparticles. X-ray diffraction peaks were conferred to face centered cubic structure. Transmission Electron Microscope and Scanning Electron Microscope revealed the spherical-shaped, polycrystalline nature with the presence of elemental silver analyzed by Energy Dispersive of X-Ray spectrum. Selected area electron diffraction also confirmed the orientation of AgNPs at 111, 200, 220, 311 planes similar to X-ray diffraction analysis. The synthesized nanoparticles are evaluated for antimicrobial activity against 7 bacterial and 3 fungal pathogens. A good zone of inhibition was observed against pathogenic bacteria than fungal pathogens. Thus the study could hold a key aspect in drug discovery research and other pharmacological conducts of human clinical conditions.

Preparation and Characterizations of Rosin Based Thin Films and Fibers.

Nirmala, R,Woo-il, Baek,Navamathavan, R,Kim, Hak Yong,Park, Soo-Jin American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.6

<P>In this study, we report the preparation and comparison of the rosin based thin films and electrospun fibers in terms of their formation and characterizations. Rosin in the form of thin films and fibers can be obtained via wet casting method and electrospinning process, respectively. Systematic experiments were performed to study the morphology, structure and thermal properties of the rosin thin films and electrospun fibers. Finally, in order to understand the accurate mass values of rosin in the different morphologies, we performed matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) spectroscopy. The rosin thin film prepared via wet casting method exhibited very smooth surfaces whereas the electrospun fibers were continuous without any beads over long distances. The MALDI-TOF data revealed that the most intense peak in the molecular weight of rosin components is about 302 for the rosin powder, thin film and fibers. On the other hand, some of the higher molecular component can also be observed for electrospun rosin fibers owing to the structural morphology. The present study demonstrated that the full structural characterization of the molecular species present in these different forms of rosin.</P>

Electrical Properties of Ultrafine Nylon-6 Nanofibers Prepared Via Electrospinning

Nirmala, R.,Jeong, Jin-Won,Oh, Hyun-Ju,Navamathavan, R.,El-Newehy, Mohamed,Al-Deyab, Salem S.,Kim, Hak-Yong 한국섬유공학회 2011 FIBERS AND POLYMERS Vol.12 No.8

We report on the preparation and electrical characterization of nylon-6 nanofibers via electrospinning technique. During electrospinning, the polymer solution became highly ionized and emerging out of the micro-tip syringe by forming mesh-like ultrafine nanofibers structure in between the main fibers. The resultant nylon-6 nanofibers were well-oriented with uniform structure. The diameter of the ultrafine nanofibers (7 to 40 nm) is one order less than those of main fibers (100 to 200 nm). The current-voltage (I-V) measurements revealed a linear curve with an occurrence of negative differential resistance (NDR) behavior. The existence of NDR region in the nylon-6 nanofibers can be attributed to the tunneling current through the ultrafine structures. The fabrication of nanofibers, in the form of ultrafine mesh-like form, is relatively fast and inexpensive, and it paves the way to build up of new dimension for nano device applications.

Role of autophagy in regulation of cancer cell death/apoptosis during anti-cancer therapy: focus on autophagy fl ux blockade

Nirmala Tilija Pun,장원준,정철호 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.5

Autophagy is a self-degradation process in whichthe cytoplasmic cargoes are delivered to the lysosomes fordegradation. As the cargoes are degraded/recycled, theautophagy process maintains the cellular homeostasis. Anticancertherapies induce apoptosis and autophagy concomitantly,and the induced autophagy normally prevents stressresponses that are being induced. In such cases, the inhibitionof autophagy can be a reasonable strategy to enhancethe effi cacy of anti-cancer therapies. However, recent studieshave shown that autophagy induced by anti-cancer drugscauses cell death/apoptosis induction, indicating a controversialrole of autophagy in cancer cell survival or death/apoptosis. Therefore, in the present review, we aimed to assessthe signaling mechanisms involved in autophagy and celldeath/apoptosis induction during anti-cancer therapies. Thisreview summarizes the process of autophagy, autophagy fl uxand its blockade, and measurement and interpretation ofautophagy fl ux. Further, it describes the signaling pathwaysinvolved in the blockade of autophagy fl ux and the role ofsignaling molecules accumulated by autophagy blockade incell death/apoptosis in various cancer cells during anti-cancertherapies. Altogether, it implies that factors such as typesof cancer, drug therapies, and characteristics of autophagyshould be evaluated before targeting autophagy for cancertreatment.

P-477 : Purification of recombinant HBsAg expressed in methylotrophic yeast Pichia pastoris

( Nirmala Bardiya ),( Yoon Mo Koo ) 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.2

Early Childhood Care and Education in Cambodia

Nirmala Rao,Veronica Pearson 육아정책연구소 2009 International Journal of Child Care and Education Vol.3 No.1

This paper analyses child care and education policy in Cambodia, a country where there is currently a strong commitment to Early Childhood Care and Education (ECCE). This is done by (i) providing an overview of national statistics related to the health and development of young Cambodian children and information about their access to ECCE programs; (ii) considering government policy, administrative structures, and funding for ECCE; and (iii) discussing the different models of preschool provision (state preschools, community preschools, home-based programs and private preschools) that are available. Recent initiatives and research findings are discussed and the implications of the analysis for policy development and young children’s well-being are considered.

Characterisation of bioresourced hydroxyapatite containing silver nanoparticles

Nirmala, R,Navamathavan, R,Afeesh, R,Park, H-M,Kang, H-S,Kim, H Y Informa UK (TaylorFrancis) 2012 Materials research innovations Vol.16 No.4

Electrospun nickel doped titanium dioxide nanofibers as an effective photocatalyst for the hydrolytic dehydrogenation of ammonia borane

Nirmala, R.,Kim, Hak Yong,Yi, Chuan,Barakat, Nasser A.M.,Navamathavan, R.,El-Newehy, Mohamed Elsevier 2012 International journal of hydrogen energy Vol.37 No.13

<P><B>Abstract</B></P><P>In this study, Ni-doped titanium dioxide (TiO<SUB>2</SUB>) electrospun nanofibers are introduced as novel material for dehydrogenation of ammonia borane (AB) complex. Hydrolysis experiments with introduced catalytic nanofibers are prevailed to rapidly release hydrogen from AB complex. Typically, Ni nanoparticles (NPs) behave as a catalyst, meanwhile the incorporation of nickel NPs lead to decrease in the electrons/holes recombination rate in TiO<SUB>2</SUB> which resulted in the increase of active ions in the solution to a rapid evolution of hydrogen gas at room temperature. The utilized physiochemical analyses indicate that the introduced Ni-doped TiO<SUB>2</SUB> nanofibers have a smooth surface and uniform diameters along their lengths. Under sunlight irradiation, the hydrogen production rate in case of utilizing Ni-doped TiO<SUB>2</SUB> nanofibers is rapidly increased compared to the pristine TiO<SUB>2</SUB> nanofibers, the maximum hydrogen equivalent in case of the doped nanofibers is 2.6 while the pristine one is 1.4. Both formulations exhibit almost equal low activity in daylight as the observed hydrogen equivalent is 0.4. Overall, this study proposes cheap, stable and effective material for AB dehydrogenation at room temperature.</P> <P><B>Highlights</B></P><P>► Novel Ni–TiO<SUB>2</SUB> photocatalyst is introduced for ammonia borane (AB) hydrolysis. ► A simple method to synthesis Ni-doped TiO<SUB>2</SUB> nanofibers for hydrogen production. ► High amount of hydrogen was produced by catalyst assisted hydrolysis. ► This is a cheap, stable and effective material for AB dehydrogenation. ► The introduced photocatalyst reveal good performance even at low content.</P>

Effect of Solvents on High Aspect Ratio Polyamide-6 Nanofibers via Electrospinning

Nirmala, R.,Panth, Hem Raj,Yi, Chuan,Nam, Ki-Taek,Park, Soo-Jin,Kim, Hak-Yong,Navamathavan, R. 한국고분자학회 2010 Macromolecular Research Vol.18 No.8

The effect of the solvent on the formation of high aspect ratio ultrafine fibers in polyamide-6 using an electrospinning technique was examined systematically. In this study, formic acid, dichloromethane, acetic acid, chlorophenol, hexafluoroisopropanol, and trifluoroacetic acid via single and mixed solvent system were used for the production of high aspect ratio nanofibers in polyamide-6. Formic acid and mixtures of formic acid/dichloromethane, formic acid/acetic acid, and formic acid/chlorophenol can lead to the very clear dissolution of polyamide-6, enabling their subsequent electrospinning to obtain high aspect ratio nanofibers. Formic acid was found to be the most suitable solvent system for obtaining high aspect ratio nanofibers in polyamide-6. The conductivity of polyamide-6 in formic acid was very high demonstrating an increasing level of free ions in solution. The average diameter of the high aspect ratio nanofibers was approximately one order of magnitude lower than that of main fibers. These findings suggest that the formation of high aspect ratio nanofibers relies strongly on the specific properties, such as the poly-electrolytic behavior of polyamide-6 in the solvent.