Magnetic ground state of the multiferroic hexagonal LuFeO3

Suresh, Pittala,Vijaya Laxmi, K.,Bera, A. K.,Yusuf, S. M.,Chittari, Bheema Lingam,Jung, Jeil,Anil Kumar, P. S. American Physical Society 2018 Physical Review B Vol.97 No.18

<P>The structural, electric, and magnetic properties of bulk hexagonal LuFeO3 are investigated. Single phase hexagonal LuFeO3 has been successfully stabilized in the bulk form without any doping by sol-gel method. The hexagonal crystal structure with P6(3)cm space group has been confirmed by x-ray-diffraction, neutron-diffraction, and Raman spectroscopy study at room temperature. Neutron diffraction confirms the hexagonal phase of LuFeO3 persists down to 6 K. Further, the x-ray photoelectron spectroscopy established the 3+ oxidation state of Fe ions. The temperature-dependent magnetic dc susceptibility, specific heat, and neutron-diffraction studies confirm an antiferromagnetic ordering below the Neel temperature (T-N) similar to 130 K. Analysis of magnetic neutron-diffraction patterns reveals an in-plane (ab-plane) 120 degrees antiferromagnetic structure, characterized by a propagation vector k = (0 0 0) with an ordered moment of 2.84 mu(B)/Fe3+ at 6 K. The 120 degrees antifferomagnetic ordering is further confirmed by spin-orbit coupling density functional theory calculations. The on-site coulomb interaction (U) and Hund's parameter (J(H)) on Fe atoms reproduced the neutron-diffraction Gamma(1) spin pattern among the Fe atoms. P-E loop measurements at room temperature confirm an intrinsic ferroelectricity of the sample with remnant polarization P-r similar to 0.18 mu(C) cm(2). A clear anomaly in the dielectric data is observed at similar to T-N revealing the presence of magnetoelectric coupling. A change in the lattice constants at T-N has also been found, indicating the presence of a strong magnetoelastic coupling. Thus a coupling between lattice, electric, and magnetic degrees of freedom is established in bulk hexagonal LuFeO3.</P>

Protective Effect of Pterocarpus santalinus onGalactosamine Induced Liver Damage

S. P. Dhanabal,G. Syamala,K. Elango,B. Suresh 한국생약학회 2006 Natural Product Sciences Vol.12 No.1

Pterocarpus santalinus Linn on acute hepatotoxicity induced in Wistar albino rats by a single dose ofGalactosamine (400 mg/kg). Suspensions of methanolic extract of heartwood of P. santalinus (200 and 400 mg/kg)in 0.3% Carboxy Methyl Cellulose (CMC) were administered p.o. to experimental animals and hepatoprotectiveactivity was monitored by estimating aspartate amino transferase (ASAT, GOT), alanine amino transferase(ALAT, GPT), alkaline phosphatase (ALP), total bilirubin (TB), lactate dehydrogenase (LDH), total cholesterolelevation of serum transaminases and alterations of biochemical parameters induced by hepatotoxin, andalleviated the degree of liver damage. The results were supported by histopathological studies of liver samplesshowing regeneration of hepatocytes in treated animals. Silymarin (25 mg/kg), a known hepatoprotective drug wasused for comparison. Based on the results obtained, it can be concluded that P. santalinus exerts hepatoprotectiveactivity and may serve as a useful adjuvant in several clinical conditions associated with liver damage.Keywords Pterocarpus santalinus

Endocrine Profiles of Oestrous Cycle in Buffalo: A Meta-analysis

Mondal, S.,Suresh, K.P.,Nandi, S. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.2

A meta-analysis was conducted to summarize the results of studies which have described the profiles of hormones during the oestrous cycle in buffalo using a fixed effect model and a random effect model. Plasma progesterone concentrations were lowest (0.30${\pm}$0.06 ng/ml) during the peri-oestrous phase and increased (p = 0.067) through the early luteal phase to a maximum concentration (1.94${\pm}$0.03 ng/ml) during the mid-luteal phase. Circulating plasma inhibin and estradiol concentrations were lowest (0.31${\pm}$0.01 and 11.04${\pm}$0.13 ng/ml) during the mid-luteal phase, increased through the late luteal phase to maximum concentrations (0.44${\pm}$0.02 and 22.48${\pm}$0.32 ng/ml) during the peri-oestrous phase. Plasma FSH concentrations were lowest during the early luteal phase and increased through the mid-luteal phase to a maximum concentration during the peri-oestrous phase. Peripheral prolactin concentrations were lowest during the late luteal phase and increased to a maximum concentration during the peri-oestrous phase which then declined (p = 0.716) during the early luteal phase. Peripheral plasma cortisol concentrations decreased from 2.68${\pm}$0.14 ng/ml during the early luteal phase to 1.43${\pm}$0.27 ng/ml during the mid-luteal phase (p<0.001) which then increased to 2.06${\pm}$0.17 ng/ml during the late luteal phase. Plasma $T_{5}$ concentrations decreased from the late luteal phase to the peri-oestrous phase (p<0.001) which then increased during the early luteal phase. $T_{4}$ concentrations increased from the late luteal phase to the peri-oestrous phase which then decreased during the early luteal phase.

Cytotoxicity, Apoptosis Induction and Anti-Metastatic Potential of Oroxylum indicum in Human Breast Cancer Cells

Kumar, D.R. Naveen,George, V. Cijo,Suresh, P.K.,Kumar, R. Ashok Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Despite clinical advances in anticancer therapy, there is still a need for novel anticancer metabolites, with higher efficacy and lesser side effects. Oroxylum indicum (L.) Vent. is a small tree of the Bignoniaceae family which is well known for its food and medicinal properties. In present study, the chemopreventive properties of O. indicum hot and cold non-polar extracts (petroleum ether and chloroform) were investigated with MDA-MB-231 (cancer cells) and WRL-68 (non-tumor cells) by XTT assay. All the extracts, and particularly the petroleum ether hot extract (PHO), exhibited significantly (P<0.05) higher cytotoxicity in MDA-MB-231 when compared to WRL-68 cells. PHO was then tested for apoptosis induction in estrogen receptor (ER)-negative (MDA-MB-231) and ER-positive (MCF-7) breast cancer cells by cellular DNA fragmentation ELISA, where it proved more efficient in the MDA-MB-231 cells. Further, when PHO was tested for anti-metastatic potential in a cell migration inhibition assay, it exhibited beneficial effects. Thus non-polar extracts of O. indicum (especially PHO) can effectively target ER-negative breast cancer cells to induce apoptosis, without harming normal cells by cancer-specific cytotoxicity. Hence, it could be considered as an extract with candidate precursors to possibly harness or alleviate ER-negative breast cancer progression even in advanced stages of malignancy.

Quantitative Assessment of the Relative Antineoplastic Potential of the n-butanolic Leaf Extract of Annona Muricata Linn. in Normal and immortalized Human Cell Lines

George, V. Cijo,Kumar, D.R. Naveen,Rajkumar, V.,Suresh, P.K.,Kumar, R. Ashok Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Natural products have been the target for cancer therapy for several years but there is still a dearth of information on potent compounds that may protect normal cells and selectively destroy cancerous cells. The present study was aimed to evaluate the cytotoxic potential of n-butanolic leaf extract of $Annona$ $muricata$ L. on WRL-68 (normal human hepatic cells), MDA-MB-435S (human breast carcinoma cells) and HaCaT (human immortalized keratinocyte cells) lines by XTT assay. Prior to cytotoxicity testing, the extract was subjected to phytochemical screening for detecting the presence of compounds with therapeutic potential. Their relative antioxidant properties were evaluated using the reducing power and $DPPH^*$radical scavenging assay. Since most of the observed chemo-preventive potential invariably correlated with the amount of total phenolics present in the extract, their levels were quantified and identified by HPLC analysis. Correlation studies indicated a strong and significant (P<0.05) positive correlation of phenolic compounds with free radical scavenging potential. The results revealed that the extract was moderately cytotoxic to normal cells with a mean IC50 value of 52.4 ${\mu}g$ when compared with those obtained for cancerous cells (IC50 values of 29.2 ${\mu}g$ for MDA-MB-435S and 30.1 ${\mu}g$ for HaCaT respectively). The study confirms the presence of therapeutically active antineoplastic compounds in the n-butanolic leaf extract of $Annona$ $muricata$. Isolation of the active metabolites from the extract is in prospect.

Deposition rate dependent phase/mechanical property evolution in zirconia and ceria-zirconia thin film by EB-PVD technique

Arunkumar, P.,Aarthi, U.,Sribalaji, M.,Mukherjee, B.,Keshri, Anup Kumar,Tanveer, Waqas Hassan,Cha, Suk-Won,Babu, K. Suresh Elsevier 2018 Journal of alloys and compounds Vol.765 No.-

<P><B>Abstract</B></P> <P>Pure zirconia (ZrO<SUB>2</SUB>) and ceria (16 mol%) stabilized zirconia (CeSZr) thin films were prepared by electron beam physical vapor deposition with varying deposition rates (1, 4 and 8 Å/s) in order to correlate the phase changes to the mechanical property. X-ray diffraction and Raman spectra results indicate the presence of mixed monoclinic and tetragonal phases in ZrO<SUB>2</SUB> film, but tetragonal phase dominated at lower deposition rate. However, irrespective of the deposition rate, cerium addition to ZrO<SUB>2</SUB> resulted in complete stabilization of tetragonal phase. Depending on the presence of dual (ZrO<SUB>2</SUB>) or single (CeSZr) phase, either surface cracks or well-connected grain structure was observed in SEM, respectively. Thus, CeSZr film showed a four-fold increase in hardness in comparison to ZrO<SUB>2</SUB>, which can be attributed to the complete stabilization of tetragonal phase that hinders the crack propagation along the grain. Plastic deformation of CeSZr film was found to be 1.80 × 10<SUP>−2</SUP> GPa, which is about ∼55% higher as compared to pure ZrO<SUB>2</SUB> film (8.04 × 10<SUP>−3</SUP> GPa). Thus, the development of CeSZr coating may lead to better surface protection of many components.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Zirconia and ceria (16 mol%) stabilized zirconia (CeSZr) films deposited by EB-PVD. </LI> <LI> ZrO2 thin film showed mixed tetragonal and cubic structure. </LI> <LI> CeSZr thin film formed with single phase tetragonal structure. </LI> <LI> CeSZr film exhibited a four-fold increase in hardness in comparison to ZrO2 film. </LI> <LI> Deposition rate and chemistry influence the mechanical property of films. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Drastic photocatalytic degradation of methylene blue dye by neodymium doped zirconium oxide as photocatalyst under visible light irradiation

Dhandapani, C.,Narayanasamy, R.,Karthick, S.N.,Hemalatha, K.V.,Selvam, S.,Hemalatha, P.,kumar, M. Suresh,Kirupha, S. Dinesh,Kim, Hee-Je Elsevier 2016 OPTIK -STUTTGART- Vol.127 No.22

<P><B>Abstract</B></P> <P>Nanocrystalline ZrO<SUB>2</SUB> and neodymium doped ZrO<SUB>2</SUB> (Nd–ZrO<SUB>2</SUB>) were successfully prepared by a polymer- assisted, sol-gel method and characterized by XRD, SEM, HRTEM, XPS and UV–vis techniques. X-Ray diffraction studies revealed the formation of highly crystalline structures of ZrO<SUB>2</SUB> and (Nd–ZrO<SUB>2</SUB>) samples. SEM images proved the evenly distributed nano - structured, spherically - shaped ZrO<SUB>2</SUB> particles of size 40nm, which was reduced to 20nm, when doped with neodymium. Light absorption properties of the nanoparticles were studied by UV–vis spectrophotometer. Nd - doped ZrO<SUB>2</SUB> was having a band gap of 2.8ev, while that of ZrO<SUB>2</SUB>, was 2.6ev. Thus, Nd substituted ZrO<SUB>2</SUB> effected substantial shifting of the absorption edge of zirconium oxide to red and resulting in the enhancement of visible light absorption The increase in band gap of Nd–ZrO<SUB>2</SUB> was resulted in an increasing light absorbtion tendency of Nd−ZrO<SUB>2</SUB>, which promoted the photocatalytic efficiency of it. XPS results confirmed substitution of Nd in ZrO<SUB>2</SUB>. Photocatalytic results for the degradation of methylene blue had indicated the fact that neodymium substitution dramatically enhanced the catalytic activity of zirconium oxide. This means that the neodymium − substituted zirconium oxide has the highest photocatalytic activity under visible light irradiation.</P>

Improved dielectric and AC conductivity properties of P(VDF-TrFE)-Nafion blends for high-temperature flexible capacitor applications

Thirmal C.,Mohan P. Nikhil,Suresh G.,Raju K.C. James,Vishwam T. 한국물리학회 2022 Current Applied Physics Vol.44 No.-

The free-standing poly (vinylidene fluoride-trifluoroethylene) [P(VDF-TrFe)] and P(VDF-TrFe)-Nafion blended films were fabricated using the casting method. The XRD and FTIR confirmed the electro-active β-phase of P (VDF-TrFe). The morphological changes were studied through SEM analysis of the blends. The dielectric and ac conductivity measurements were carried out as a function of temperature from 30 ◦C to 130 ◦C in the frequency range of 100 Hz - 1 MHz. The dielectric constant reveled a ferroelectric to paraelectric transition in all the samples with a decrease in the transition temperature of the blends. The temperature-dependent ac conductivity and power law analysis demonstrated the presence of a correlated barrier hoping mechanism with a change in the motional behavior in the blends. The blended films exhibited low dielectric loss and more stable dielecric properties with temperature in comparison to P(VDF-TrFe). These films demonstrated the potential to be used in high-temperature flexible capacitor applications.

Modeling and Forecasting Livestock Feed Resources in India Using Climate Variables

Suresh, K.P.,Kiran, G. Ravi,Giridhar, K.,Sampath, K.T. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.4

The availability and efficient use of the feed resources in India are the primary drivers to maximize productivity of Indian livestock. Feed security is vital to the livestock management, extent of use, conservation and productivity enhancement. Assessment and forecasting of livestock feed resources are most important for effective planning and policy making. In the present study, 40 years of data on crop production, land use pattern, rainfall, its deviation from normal, area under crop and yield of crop were collected and modeled to forecast the likely production of feed resources for the next 20 years. The higher order auto-regressive (AR) models were used to develop efficient forecasting models. Use of climatic variables (actual rainfall and its deviation from normal) in combination with non-climatic factors like area under each crop, yield of crop, lag period etc., increased the efficiency of forecasting models. From the best fitting models, the current total dry matter (DM) availability in India was estimated to be 510.6 million tonnes (mt) comprising of 47.2 mt from concentrates, 319.6 mt from crop residues and 143.8 mt from greens. The availability of DM from dry fodder, green fodder and concentrates is forecasted at 409.4, 135.6 and 61.2 mt, respectively, for 2030.

Combined in silico modeling and metabolomics analysis to characterize fed‐batch CHO cell culture

Selvarasu, Suresh,Ho, Ying Swan,Chong, William P. K.,Wong, Niki S. C.,Yusufi, Faraaz N. K.,Lee, Yih Yean,Yap, Miranda G. S.,Lee, Dong‐,Yup Wiley Subscription Services, Inc., A Wiley Company 2012 Biotechnology and bioengineering Vol.109 No.6

<P><B>Abstract</B></P><P>The increasing demand for recombinant therapeutic proteins highlights the need to constantly improve the efficiency and yield of these biopharmaceutical products from mammalian cells, which is fully achievable only through proper understanding of cellular functioning. Towards this end, the current study exploited a combined metabolomics and in silico modeling approach to gain a deeper insight into the cellular mechanisms of Chinese hamster ovary (CHO) fed‐batch cultures. Initially, extracellular and intracellular metabolite profiling analysis shortlisted key metabolites associated with cell growth limitation within the energy, glutathione, and glycerophospholipid pathways that have distinct changes at the exponential‐stationary transition phase of the cultures. In addition, biomass compositional analysis newly revealed different amino acid content in the CHO cells from other mammalian cells, indicating the significance of accurate protein composition data in metabolite balancing across required nutrient assimilation, metabolic utilization, and cell growth. Subsequent in silico modeling of CHO cells characterized internal metabolic behaviors attaining physiological changes during growth and non‐growth phases, thereby allowing us to explore relevant pathways to growth limitation and identify major growth‐limiting factors including the oxidative stress and depletion of lipid metabolites. Such key information on growth‐related mechanisms derived from the current approach can potentially guide the development of new strategies to enhance CHO culture performance. Biotechnol. Bioeng. 2012; 109:1415–1429. © 2012 Wiley Periodicals, Inc.</P>