X-RAY ASTRONOMY EXPERIMENT ON THE INDIAN SATELLITE IRS-P3

AGRAWAL P. C.,PAUL B.,RAO A. R.,SHAH M. R.,MCKERJEE K.,VARIA M. N.,YADAV J. S.,DEDHIA D. K.,MALKAR J. P.,SHAH P.,DAMLE S. V.,MARAR T. M. K.,SEETHA S. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of $98^{\circ}$ and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas ($90\%$ Ar + $10\%\;CH_4$) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of $2^{\circ}{\times}2^{\circ}$ defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 $cm^2$. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 $cm^2$ area placed 16 cm above the anode plane of a 32 cm$\times$32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

Emerging Technologies in the Treatment of Adult Spinal Deformity

Akshar V. Patel,Christopher A. White,John T. Schwartz,Nicholas L. Pitaro,Kush C. Shah,Sirjanhar Singh,Varun Arvind,Jun S. Kim,Samuel K. Cho 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Outcomes for adult spinal deformity continue to improve as new technologies become integrated into clinical practice. Machine learning, robot-guided spinal surgery, and patient-specific rods are tools that are being used to improve preoperative planning and patient satisfaction. Machine learning can be used to predict complications, readmissions, and generate postoperative radiographs which can be shown to patients to guide discussions about surgery. Robot-guided spinal surgery is a rapidly growing field showing signs of greater accuracy in screw placement during surgery. Patient-specific rods offer improved outcomes through higher correction rates and decreased rates of rod breakage while decreasing operative time. The objective of this review is to evaluate trends in the literature about machine learning, robot-guided spinal surgery, and patient-specific rods in the treatment of adult spinal deformity.

Glow discharge plasma-induced immobilization of heparin and insulin on polyethylene terephthalate film surfaces enhances anti-thrombogenic properties

Pandiyaraj, K.N.,Selvarajan, V.,Rhee, Y.H.,Kim, H.W.,Shah, S.I. Elsevier 2009 Materials science & engineering. C, Materials for Vol.29 No.3

Polyethylene terephthalate (PET) films were treated with DC glow discharge plasma followed by graft copolymerization with acrylic acid (AA) and polyethylene glycol (PEG). The obtained PET-PEG was coupled to heparin or insulin molecules. The surfaces were then characterized by contact angle measurements, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The surface energies of the modified PET films were estimated using contact angle measurements, and the changes in crystallinity of the plasma-modified PET film surfaces were investigated by X-ray diffraction (XRD) analysis. The blood compatibilities of the surface-modified PETs were examined by in vitro thrombus formation, whole blood clotting time, platelet contact and protein adsorption experiments. The results revealed that the contact angle value decreased and that the interfacial tension between the modified PET films and blood protein was drastically diminished compared to unmodified PET film. The XPS results showed that the PET-AA surface containing carboxylic acid and the immobilized PET surface containing both carboxylic acid and amino groups exhibited a hydrophilic character, and AFM results showed marked morphological changes after grafting of AA, PEG and biomolecule immobilization. Heparin and insulin-coupled PET surfaces exhibited much less platelet adhesion and protein adsorption than the other surface-modified PET film surfaces.

Loss of von Hippel-Lindau Protein (VHL) Increases Systemic Cholesterol Levels through Targeting Hypoxia-Inducible Factor 2α and Regulation of Bile Acid Homeostasis

Ramakrishnan, Sadeesh K.,Taylor, Matthew,Qu, Aijuan,Ahn, Sung-Hoon,Suresh, Madathilparambil V.,Raghavendran, Krishnan,Gonzalez, Frank J.,Shah, Yatrik M. American Society for Microbiology 2014 Molecular and cellular biology Vol.34 No.7

<P>Cholesterol synthesis is a highly oxygen-dependent process. Paradoxically, hypoxia is correlated with an increase in cellular and systemic cholesterol levels and risk of cardiovascular diseases. The mechanism for the increase in cholesterol during hypoxia is unclear. Hypoxia signaling is mediated through hypoxia-inducible factor 1α (HIF-1α) and HIF-2α. The present study demonstrates that activation of HIF signaling in the liver increases hepatic and systemic cholesterol levels due to a decrease in the expression of cholesterol hydroxylase CYP7A1 and other enzymes involved in bile acid synthesis. Specifically, activation of hepatic HIF-2α (but not HIF-1α) led to hypercholesterolemia. HIF-2α repressed the circadian expression of Rev-erbα, resulting in increased expression of E4BP4, a negative regulator of <I>Cyp7a1</I>. To understand if HIF-mediated decrease in bile acid synthesis is a physiologically relevant pathway by which hypoxia maintains or increases systemic cholesterol levels, two hypoxic mouse models were assessed, an acute lung injury model and mice exposed to 10% O<SUB>2</SUB> for 3 weeks. In both models, cholesterol levels increased with a concomitant decrease in expression of genes involved in bile acid synthesis. The present study demonstrates that hypoxic activation of hepatic HIF-2α leads to an adaptive increase in cholesterol levels through inhibition of bile acid synthesis.</P>

Effect of Oroxylum indicum on intestinal motility in rodents

Joshi, Shrikant V.,Gandhi, Tejal R.,Vyas, Bhavin A.,Shah, Payal D.,Patel, Paras K.,Vyas, Heta G. 경희한의학연구센터 2012 Oriental Pharmacy and Experimental Medicine Vol.12 No.4

Oroxylum indicum is traditional herbal medicine in India, China and Japan used for its anti-diarrhoeal/anti-dysenteric activity, also found to be active against experimentally induced (DNBS induced) inflammatory bowel disease in rats with potential reduction in diarrhoea. It promotes us to evaluate effects of Oroxylum indicum on intestinal motility, both in vitro and in vivo, in rodents. Flavonoids rich fraction of O. indicum was obtained and the effect of extract on contraction of acetylcholine, barium chloride and electrical field stimulation was studied on isolated rabbit ileum. Anti-diarrhoeal activities were investigated using castor oil and magnesium sulphate-induced diarrhoeal models in mice. Effect on intestinal motility was studied using gastrointestinal motility and antienteropooling assay methods. Antimicrobial activity of extract was evaluated using disc diffusion assay method. Extract inhibited the contractions induced by acetylcholine, barium chloride and electrical field stimulation. Verapamil potentiates inhibitory effect of extract. Extract showed significant and dose-dependent antidiarrhoeal effect devoid of altering gastrointestinal motility in normal animals. It also inhibited the microbial growth in disc diffusion assay method. Extract normalized intestinal motility altered by inflammatory stimulus and possesses antidiarrhoeal activity. Alteration of intestinal motility may involve modification in L-type $Ca^{2+}$ channels.

Hematological and biochemical reference intervals of wild-caught and inhouse adult Indian rhesus macaques (Macaca mulatta)

Niraj A. Shah,Laxit K. Bhatt,Rajesh J. Patel,Tushar M. Patel,Nayankumar V. Patel,Harshida G. Trivedi,Nilam R. Patel,Jitendra H. Patel,Satish D. Patel,Rajesh S. Sundar,Mukul R. Jain 한국실험동물학회 2022 Laboratory Animal Research Vol.38 No.4

Background: Nonhuman primates are used for research purposes such as studying diseases and drug discovery and development programs. Various clinical pathology parameters are used as biomarkers of disease conditions in biomedical research. Detailed reports of these parameters are not available for Indian-origin rhesus macaques. To meet the increasing need for information, we conducted this study on 121 adult Indian rhesus macaques (57 wild-sourced and 64 inhouse animals, aged 3–7 years). A total of 18 hematology and 18 biochemistry parameters were evaluated and reported in this study. Data from these parameters were statistically evaluated for significance amongst inhouse and wild-born animals and for differences amongst sexes. The reference range was calculated according to C28-A3 guidelines for reporting reference intervals of clinical laboratory parameters. Results: Source of the animals and sex appeared to have statistically significant effects on reference values and range. Wild-born animals reported higher WBC, platelets, neutrophils, RBC, hemoglobin, HCT, MCV, and total protein values in comparison to inhouse monkeys. Sex-based differences were observed for parameters such as RBCs, hemoglobin, HCT, creatinine, calcium, phosphorus, albumin, and total protein amongst others. Conclusions: Through this study, we have established a comprehensive data set of reference values and intervals for certain hematological and biochemical parameters which will help researchers in planning, conducting, and interpreting various aspects of biomedical research employing Indian-origin rhesus monkeys.

Comparative study on nano-crystalline titanium dioxide catalyzed photocatalytic degradation of aromatic carboxylic acids in aqueous medium

P.A. Joshi,V.G. Gandhi,M.K. Mishra,M.S. Rao,A. Kumar,D.O. Shah 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.2

The comparative study on titanium dioxide (TiO2) catalyzed photocatalytic degradation (PCD) of aqueous aromatic carboxylic acids (phthalic acid, o-nitrobenzoic acid, o-chlorobenzoic acid and benzoic acid) was carried out in the presence of UV radiation using air. The TiO2 catalyst, synthesized by sol–gel technique and calcined at 673 K, resulted ca. 100% anatase phase with 23 nm crystallite size and surface area of 37 m2/g. This catalyst was found to be efficient for PCD of phthalic acid, o-nitrobenzoic acid, ochlorobenzoic acid and benzoic acid in aqueous medium. However, the reactivity and degradation pathway of these carboxylic acids were observed to be greatly influenced by the substituent group present in the aromatic ring. The order of degradation of aromatic carboxylic acids was found to be phthalic acid > o-nitrobenzoic acid > o-chlorobenzoic acid > benzoic acid. The aromatic carboxylic acids having electron withdrawing groups such as –COOH, –NO2 and –Cl were comparatively more reactive for PCD than unsubstituted aromatic acid i.e., benzoic acid. The degradation of ortho substituted benzoic acids (having electron withdrawing groups) follows different mechanistic pathway than that of benzoic acid. Study of various operational parameters like effect of catalyst loading, initial concentration of phthalic acid and kinetics of phthalic acid PCD was also carried out in batch type photocatalytic reactor.

Spin Transport in Ge at Room Temperature

C. Shen,T. Trypiniotis,K. Y. Lee,S. N. Holmes,R. Mansell,M. K. Husain,V. Shah,H. Kurebayashi,I. Farrer,K. de Groot,D. R. Leadley,G. Bell,E. H. Parker,T. Whall,D. A. Ritchie,C. H. W. Barnes 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

Structural studies of Mn doped ZnO nanoparticles

B.N. Dole,V.D. Mote,V.R. Huse,Y. Purushotham,M.K. Lande,K. M. Jadhav,S.S. Shah 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Mn substituted ZnO nanoparticles with compositional formula Zn_(1-x)Mn_xO where x = 0.00, 0.04 and 0.08were synthesized by sol-gel route. All the samples sintered at 650 ℃ for 12 h in a furnace followed by furnace cooling up to room temperature. X-ray diffraction (XRD) studies shows the presence of hexagonal crystal structure as same as parent compound (ZnO) in all samples. The lattice parameters ‘a’ and ‘c’were determined from XRD data and found that they increase linearly with the Mn content, which suggests that doped Mn ions go to Zn sites. Grain size, X-ray density and Atomic packing fraction (APF)were evaluated using XRD data and found that grain size increases while X-ray density and Atomic packing fraction (APF) decreases with dopant concentration increases. The functional groups and chemical interactions of Mn substituted Zinc oxide samples were also determined at various peaks using FTIR data and observed the presence of function groups in the samples. Results of such an investigation presented in this paper.

Charge transport studies on chemically grown manganite based heterostructures

Keval Gadani,Khushal Sagapariya,K.N. Rathod,Hetal Boricha,Bhargav Rajyaguru,V.G. Shrimali,A.D. Joshi,K. Asokan,N.A. Shah,P.S. Solanki 한국물리학회 2019 Current Applied Physics Vol.19 No.4

In this communication, we have successfully fabricated mixed valent La0.7Ca0.3MnO3 (LCMO) manganite based (i) ZnO/LCMO/LAO and (ii) LMO/LCMO/LAO (LMO: LaMnO3–d thin layer; LAO: LaAlO3 substrate) thin film heterostructures using chemical solution deposition (CSD) method. 100 nm LCMO layer was initially grown on single crystalline (100) LAO substrate followed by the growth of 50 nm ZnO and LMO layers separately on the two different heterostructures. In the present study, upper layers of ZnO and LMO were intentionally prepared at 700 °C for 12 h under air environment, thereby some naturally created oxygen vacancies are expected to be present in their lattices. Presence of oxygen vacancies makes ZnO and LMO layers as n–type oxides in the heterostructures. Temperature dependent current–voltage (I–V) characteristics and interface resistivity (under different applied electric fields across interface only) were carried out to understand their charge transport behavior. A strong effect of electric field on the resistivity behavior has been observed due to a reasonable electrically polarizable (active) nature of ZnO and LMO thin layers. Zener double exchange (ZDE) polynomial law has been employed to understand various scattering processes as source of resistivity across, both, ZnO/ LCMO and LMO/LCMO interfaces. Transport properties and charge conduction mechanisms have been discussed and compared for both the interfaces in the context of interface state and barrier between electrically active layer and LCMO film. Also, power consumption criteria have been discussed in detail for the presently studied heterostructures for their practical device applications such as field effect devices, memory devices, read–write head devices or any other spintronic devices.