A Key Metabolic Regulator of Bone and Cartilage Health

Elizabeth Pérez-Hernández,Jesús Javier Pastrana-Carballo,Fernando Gómez-Chávez,Ramesh C. Gupta,Nury Pérez-Hernández 대한내분비학회 2022 Endocrinology and metabolism Vol.37 No.4

Taurine, a cysteine-derived zwitterionic sulfonic acid, is a common ingredient in energy drinks and is naturally found in fish and other seafood. In humans, taurine is produced mainly in the liver, and it can also be obtained from food. In target tissues, such as the retina, heart, and skeletal muscle, it functions as an essential antioxidant, osmolyte, and antiapoptotic agent. Taurine is also involved in energy metabolism and calcium homeostasis. Taurine plays a considerable role in bone growth and development, and high-profile reports have demonstrated the importance of its metabolism for bone health. However, these reports have not been collated for more than 10 years. Therefore, this review focuses on taurine–bone interactions and covers recently discovered aspects of taurine’s effects on osteoblastogenesis, osteoclastogenesis, bone structure, and bone pathologies (e.g., osteoporosis and fracture healing), with due attention to the taurine–cartilage relationship.

Tailoring opto-electronic and interface properties via electrochemical doping in Poly(3-hexylthiophene)

V Vaibhav,Varade Ashish,P Anjaneyulu,Kumar Anup,K. P Ramesh 한국물리학회 2023 Current Applied Physics Vol.52 No.-

The thin films of electropolymerized poly(3-hexylthiophene) [e-P3HT] are simultaneously doped on the transparent indium tin oxide substrate via anodic oxidation. Distinctive doping levels are achieved by systematically de-doping the films in a reverse bias electrochemical process. Raman characterization shows the presence of doping-induced polarons. In the UV–Vis spectrum, two distinct absorption regions are found for P3HT suggesting the presence of doping-induced polarons and the Urbach calculations reveal a fine-tuning of bandgap with doping level. Further, the PL studies show exponential quenching in intensity due to charge transfer which can be precisely tuned by the doping level in the e-P3HT. The current-voltage measurements under the illumination of a 532 nm laser on a sandwich device with top contact of silver are also performed and it is found that an optimized doping level is essential to acquire the best photo response. Impedance spectroscopy on the devices and their equivalent circuit analysis reveals that in addition to the bulk system, doping can also vastly modify the interfacial properties. Our studies pave the direction to tailor and optimize different optoelectronic and interface-related properties of e-P3HT thin films via electrochemical doping for optimized optoelectronic devices and applied physics studies.

Development of open-set test in Marathi language for assessing speech identification performance of native children

S. B. Rathna Kumar,Udit Saxena,P. Phani Krishna,Abhijeet Ramesh Shinde,Ketaki Vinayak Borkar 한국언어재활사협회 2020 Clinical Archives of Communication Disorders Vol.5 No.2

Purpose: Speech identification score (SIS) testing has been used in every phase of the audiological test battery. We developed an open-set test in Marathi for assessing the speech identification performance of native children. Methods: The development of the test took place in three phases which included the development of word lists, recording of word lists, and SIS testing. The developed test consisted of four word-lists with each list consisting of 15 monosyllabic words in CVC structure and 10 disyllabic words in CVCV structure. The recording was performed in a sound-treated room where ambient noise levels were maintained as per the permissible levels. SIS testing was performed on a total of 90 children with normal hearing who were equally divided into three groups. Groups I, II, and III consisted of children in the range between 6 and 6.11 years, 7 and 7.11 years, and 8 and 8.11 respectively. Results: The data were subjected to one-way ANOVA and the results revealed no statistically significant difference (p>0.05) in SIS between three groups for each word list and between four word-lists for each group. The overall groups’ mean SIS were 99.15%, 98.97%, 99.06%, and 99.02% for four word-lists respectively, and were falling within the normal range (90 to 100%). Conclusions: Findings of the present study are in line with the findings of research reports on other Indian languages. The four word-lists developed in the present study were found to be equally difficult, reliable, and valid test materials in Marathi for assessing native children.

Enhanced properties of porous CoFe₂O₄–reduced graphene oxide composites with alginate binders for Li-ion battery applications

Kumar, P. Ramesh,Kollu, Pratap,Santhosh, Chella,Eswara Varaprasada Rao, K.,Kim, Do Kyung,Grace, Andrews Nirmala The Royal Society of Chemistry 2014 NEW JOURNAL OF CHEMISTRY Vol.38 No.8

<P>Porous CoFe<SUB>2</SUB>O<SUB>4</SUB> nanoclusters with different concentrations of graphene based composites were synthesized by a simple solvothermal process. The electrochemical properties of prepared CoFe<SUB>2</SUB>O<SUB>4</SUB>–reduced graphene oxide (rGO) composites were evaluated using polyvinylidene fluoride and Na-alginate as binder materials. The CoFe<SUB>2</SUB>O<SUB>4</SUB> + 20% rGO composite with alginate exhibited a high stable capacity of 1040 mA h g<SUP>−1</SUP> at 0.1 C (91 mA g<SUP>−1</SUP>) rate with excellent rate capability. The observed enhancement in electrochemical properties of the CoFe<SUB>2</SUB>O<SUB>4</SUB> + 20% rGO composite with alginate is due to the high stability and good transportation network while charging–discharging.</P> <P>Graphic Abstract</P><P>Porous CoFe<SUB>2</SUB>O<SUB>4</SUB> nanoclusters with different concentrations of graphene based composites were synthesized by a simple solvothermal process. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4nj00419a'> </P>

Catecholamine-Functionalized Reduced Graphene Oxide: A Scalable Carbon Host for Stable Cycling in Lithium–Sulfur Batteries

Ahad, Syed Abdul,Kumar, P. Ramesh,Kim, Joo-Hyung,Kim, Dong Jun,Ragupathy, P.,Kim, Do Kyung Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>The Lithium–Sulfur battery is a promising high performance battery candidate for large-scale application on account of its high theoretical specific capacity. However, it has come up short on delivering long cycle life mainly due to the formation of soluble polysulfides, which results in the loss of active material during redox processes. In this study, we prepared three different graphene oxide based carbon hosts − graphene oxide (GO), thermally reduced GO (t-rGO) and dopamine-assisted chemically reduced GO (c-rGO) − and investigated their physical and electrochemical properties as a sulfur cathode. We found significant absorbance of polysulfides on the c-rGO host, which provided stable discharge capacity of 601mAhg<SUP>−1</SUP> at 0.5C for up to 300 cycles. This stable cycling behavior is further identified by <I>in-situ</I> UV–vis spectroscopy and <I>ex-situ</I> X-ray photoelectron spectroscopy, confirming the minimization of polysulfide dissolution toward the electrolyte through the adsorption of polydopamine coating.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Anthropogenic disturbances shift diameter distribution of woody plant species in Shorea robusta Gaertn. (Sal) mixed forests of Nepal

Ramesh P. Sapkota,Peter D. Stahl,Urszula Norton 국립중앙과학관 2019 Journal of Asia-Pacific Biodiversity Vol.12 No.1

Assessing diameter distribution is an approach of observing regeneration strategies and impacts ofanthropogenic disturbances on forest structural attributes. In this study, we evaluated the differences indiameter distributions in highly disturbed, moderately disturbed, and undisturbed forest sites of BufferZone Community Forests (BZCFs), viz. Janajagaran BZCF, Musharni Mai BZCF, and Radha Krishna BZCF ofCentral Terai, Nepal. Weibull and gamma distributions were fitted to explain changes in frequency distribution of diameter data collected. We observed a significant decrease in species richness (overall:p < 0.001) and density of smallest diameter class (0e10 cm diameter at breast height) stems (overall:p < 0.001) with increasing disturbances. Similarly, increase in median diameters (p < 0.01) and parameters of Weibull’s and gamma distributions along gradients from undisturbed to highly disturbedforest sites (except between moderately disturbed and undisturbed sites of Musharni Mai BZCF) wereobserved. Bowley coefficient of skewness was lower in all highly disturbed sites of BZCFs showingreduction in right skewness of the distribution curves with disturbances. These results indicateanthropogenic disturbances shift diameter structure of forests stands, negatively affecting abundance ofsmall diameteresized woody species and shifting Shorea robusta mixed forests towards even-agedstands.

Epitaxial Multiferroic BiFeO3 Thin Films: Progress and Future Directions

Chu, Y. H.,Martin, L. W.,Zhan, Q.,Yang, P. L.,Cruz, M. P.,Lee, K.,Barry, M.,Yang, S. Y.,Ramesh, R. Taylor Francis 2007 Ferroelectrics Vol.354 No.1

<P> We write this article in honor of Professor Vitaly L. Ginzburg, truly the father of the field of ferroelectricity. This article serves as a review of the current state of research pertaining to multiferroic BiFeO3 thin films. In this review we will delve into details of the growth of BiFeO3 thin films and the use of piezoforce microscopy and x-ray reciprocal space mapping to characterize the crystal structure and domain structure of BiFeO3. We will also discuss the use of vicinal and asymmetric substrates to simplify the domain structure in BiFeO3. By simplifying the domain structure we can, in turn, control the ferroelectric switching mechanisms in BiFeO3. Finally we describe the basic ferroelectric properties of BFO films and discuss the critical issues needed to be solved in BiFeO3 films including leakage, complex domain structure, coercivity, and reliability. Such results are promising for continued exploration for detailed multiferroic-coupling studies in the magnetoelectric BiFeO3 system and BiFeO3, in turn, provides a model platform with which to realize the exciting possibility of electrically control magnetism.</P>

Speed Control of SR Drive Using FLC

P. Ramesh,P. Subbaiah 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.6

SRM drives might be used in distant viable applications owing to their simplicity and low cost. In this paper, the SRM Drive is described as that which is used for fuzzy modeling, estimation, prediction and control. A fuzzy-logic-based model is constructed from both static and real-time motor data, and from this model the rotor position is estimated and controlled. The system also incorporates fuzzy logic-based methods to provide a high robustness against noise. In addition, the method uses heuristic knowledge to choose the most desirable phase for angle estimation in order to minimize the effect of feedback error. It is also shown that, by using fuzzy logic, the drive control scheme offers a high robustness and reliability and be suited to a wide range of applications. Simulation results are presented to verify the proposed scheme by using in simulink /mat lab.

Interface control of bulk ferroelectric polarization.

Yu, P,Luo, W,Yi, D,Zhang, J X,Rossell, M D,Yang, C-H,You, L,Singh-Bhalla, G,Yang, S Y,He, Q,Ramasse, Q M,Erni, R,Martin, L W,Chu, Y H,Pantelides, S T,Pennycook, S J,Ramesh, R National Academy of Sciences 2012 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.109 No.25

<P>The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, the study of polar discontinuities at interfaces between complex oxides lies at the frontier of modern condensed matter research. Here we employ a combination of experimental measurements and theoretical calculations to demonstrate the control of a bulk property, namely ferroelectric polarization, of a heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, the control is achieved by exploiting the interfacial valence mismatch to influence the electrostatic potential step across the interface, which manifests itself as the biased-voltage in ferroelectric hysteresis loops and determines the ferroelectric state. A broad study of diverse systems comprising different ferroelectrics and conducting perovskite underlayers extends the generality of this phenomenon.</P>

Swiprosin-1 Regulates Cytokine Expression of Human Mast Cell Line HMC-1 through Actin Remodeling

Ramesh, T.P.,Kim, Young-Dae,Kwon, Min-Sung,Jun, Chang-Duk,Kim, Sang-Wook The Korean Association of Immunobiologists 2009 Immune Network Vol.9 No.6

Background: Swiprosin-1 was identified in human CD8+ lymphocytes, mature B cells and non-lymphonoid tissue. We have recently reported that swiprosin-1 is expressed in mast cells and up-regulated in both in vitro and in vivo. Methods: The expression of cytokines and swiprosin-1 were determined by by real time PCR and conventional PCR. Pharmacological inhibitors were treated to investigate potential mechanism of swiprosin-1 in mast cell activation. Actin content was evaluated by confocal microscopy and flow cytometry. Results: The swiprosin-1 augmented PMA/A23187-induced expression of cytokines and release of histamine. However, knock-down of swiprosin-1 showed only a modest effect on PMA/A23187-induced cytokine expression, suggesting that swiprosin-1 has gain-of-function characteristics. Swiprosin-1 was found in microvilli-like membrane protrusions and highly co-localized with F-actin. Importantly, either disruption of actin by cytochalasin B or inhibition of PI3 kinase, an enzyme involved in actin remodeling, by wortmannin blocked cytokine expression only in swiprosin-1-overexpressing cells. Conclusion: These results suggest that swiprosin-1 modulates mast cell activation potentially through actin regulation.