Research Interests:
Research Interests:
Estrogen has been found to exacerbate disease activity in murine lupus and to induce a lupus-like syndrome in nonspontaneously autoimmune mice. This has led to the consideration that estrogen may be a risk factor for the development of... more
Estrogen has been found to exacerbate disease activity in murine lupus and to induce a lupus-like syndrome in nonspontaneously autoimmune mice. This has led to the consideration that estrogen may be a risk factor for the development of systemic lupus erythematosus (SLE), and selective estrogen receptor modulators (SERM) may serve to ameliorate lupus activity. We evaluated the effects and mechanism of action of the SERM raloxifene in murine lupus. Effects of raloxifene on the development of lupus in NZB/W F1 mice were evaluated in the presence and absence of estrogen by assessing the serum DNA reactivity, glomerular IgG deposition and kidney damage, B cell maturation and selection, and activation status of marginal zone and follicular B cells. Compared to estradiol-treated mice, mice treated with estradiol and raloxifene had significantly lower serum anti-DNA antibody levels and less kidney damage. These effects of raloxifene were due, at least in part, to antagonism of the influence of estrogen on DNA-reactive B cells. Raloxifene was found to prevent estrogen-mediated suppression of autoreactive B cell elimination at the T1/T2 selection checkpoint, to reduce estrogen-induced CD40 overexpression on follicular B cells, making them less responsive to T cell costimulation, and to ameliorate estrogen-mediated CD22 downregulation on marginal zone B cells, thereby decreasing their responsiveness to B cell antigen receptor-mediated stimuli. Raloxifene suppressed estrogen-mediated effects on the survival, maturation, and activation of autoreactive B cells in NZB/W F1 mice.
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A nonaqueous reverse-phase liquid chromatographic (LC) method has been developed to determine elemental sulfur in pesticide formulations. Samples were extracted in 50 mL of stabilized tetrahydrofuran (THF) by gentle swirling while... more
A nonaqueous reverse-phase liquid chromatographic (LC) method has been developed to determine elemental sulfur in pesticide formulations. Samples were extracted in 50 mL of stabilized tetrahydrofuran (THF) by gentle swirling while sonicating for 1 min. A 5 microL aliquot was injected into the LC instrument equipped with a Vydac 218 TP 54 column. The mobile phase was methanol-acetonitrile-stabilized tetrahydrofuran (58.5 + 40 + 1.5). Sulfur was monitored at 280 nm. Retention time was approximately 5 min with total analysis time of 7 min. For 6 different products analyzed 12 times each, the coefficients of variations were all less than 3.5%. Purity of each sulfur peak was checked by using a photodiode array detector in the spectrum and absorbance ratio modes. No impurities were observed at the monitoring wavelength.
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Cis-acting type I elements regulate the initiation of DNA replication, replication fork movement, and transcription of the Tetrahymena thermophila rDNA minichromosome and are required for cell cycle-controlled replication and... more
Cis-acting type I elements regulate the initiation of DNA replication, replication fork movement, and transcription of the Tetrahymena thermophila rDNA minichromosome and are required for cell cycle-controlled replication and developmentally programmed gene amplification. Previous studies identified three in vitro single-stranded type I element binding activities that were proposed to play distinct roles in replication control. Here we describe the cloning of one of these genes, TIF1, and we provide evidence for its association with type I elements in vivo. Furthermore, we show that TIF1 interacts (in vitro and in vivo) with pause site elements (PSE), which co-localize with replication initiation and fork arrest sites, and are shown to be essential. The in vivo accessibility of PSE and type I elements to potassium permanganate suggests that origin regions are frequently unwound in native chromatin. TIF1 contains sequence similarity to the Solanum tuberosum single strand-specific transcription factor, p24, and a related Arabidopsis protein. Antisense inhibition studies suggest that TIF1 competes with other proteins for PSE and type I element binding. TIF1 displays a marked strand bias in vivo, discriminating between origin- and promoter-proximal type I elements. We propose that this bias selectively modulates the binding of a different subset of proteins to the respective regulatory elements.
Research Interests: Biological Chemistry, Biological Sciences, DNA, Mice, Animals, and 13 morePlasmids, Tetrahymena, Chromatin, CHEMICAL SCIENCES, Molecular cloning, DNA binding, Protozoan Proteins, Two-Dimensional Gel Electrophoresis, Amino Acid Sequence, Ribosomes, DNA binding proteins, Potassium Permanganate, and Molecular Sequence Data
How genetic and environmental factors interact in Parkinson disease is poorly understood. We have now compared the patterns of vulnerability and rescue of Caenorhabditis elegans with genetic modifications of three different genetic... more
How genetic and environmental factors interact in Parkinson disease is poorly understood. We have now compared the patterns of vulnerability and rescue of Caenorhabditis elegans with genetic modifications of three different genetic factors implicated in Parkinson disease (PD). We observed that expressing alpha-synuclein, deleting parkin (K08E3.7), or knocking down DJ-1 (B0432.2) or parkin produces similar patterns of pharmacological vulnerability and rescue. C. elegans lines with these genetic changes were more vulnerable than nontransgenic nematodes to mitochondrial complex I inhibitors, including rotenone, fenperoximate, pyridaben, or stigmatellin. In contrast, the genetic manipulations did not increase sensitivity to paraquat, sodium azide, divalent metal ions (Fe(II) or Cu(II)), or etoposide compared with the nontransgenic nematodes. Each of the PD-related lines was also partially rescued by the antioxidant probucol, the mitochondrial complex II activator, D-beta-hydroxybutyrate, or the anti-apoptotic bile acid tauroursodeoxycholic acid. Complete protection in all lines was achieved by combining d-beta-hydroxybutyrate with tauroursodeoxycholic acid but not with probucol. These results show that diverse PD-related genetic modifications disrupt the mitochondrial function in C. elegans, and they raise the possibility that mitochondrial disruption is a pathway shared in common by many types of familial PD.
Research Interests: Caenorhabditis elegans, Mitochondria, Biological Chemistry, Apoptosis, Alpha Synuclein, and 23 moreBiological Sciences, Antioxidants, Humans, Mutagenesis, Mutation, Copper, Animals, Biological, Genetic modification, Iron, Neurons, Paraquat, CHEMICAL SCIENCES, Time Factors, Pyrazoles, Thiazoles, Amino Acid Sequence, Oxygen Consumption, Ions, Parkinson Disease, Gene Expression Regulation, Immunoblotting, and Molecular Sequence Data
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Research Interests:
The objective of this study was to explore the possibility of a recurrent increase in the ovulation rate of Malpura sheep, a non-prolific breed, by immunization against inhibin-based peptide immunogens over a period of 3 years. Adult ewes... more
The objective of this study was to explore the possibility of a recurrent increase in the ovulation rate of Malpura sheep, a non-prolific breed, by immunization against inhibin-based peptide immunogens over a period of 3 years. Adult ewes (4–7 years of age) and weighing between 28 and 38kg were randomly allocated equally to three treatment groups. The immunization of the
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Research Interests:
Ultrathin (< 10 nm) zirconium oxide (ZrO2) films have been deposited at low temperature (150° C) on strained-Si on relaxed-Si0. 8Ge0. 2 substrates by microwave plasma enhanced chemical vapor deposition (PECVD). Interfacial and... more
Ultrathin (< 10 nm) zirconium oxide (ZrO2) films have been deposited at low temperature (150° C) on strained-Si on relaxed-Si0. 8Ge0. 2 substrates by microwave plasma enhanced chemical vapor deposition (PECVD). Interfacial and electrical properties of Al/ZrO2/strained-Si MOS capacitors have been characterized using capacitance–voltage (C–V) and conductance–voltage (G–V) techniques. It is observed that Dit ranges from 4.93× 1012 eV− 1 cm− 2 in (EC− 0.35) eV to 1.86× 1012 eV− 1 cm− 2 in (EC− 0.82) eV and decays slowly ...
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The physical model considered here is a lid-driven enclosure with bottom heating and top cooling conditions, and a heat generating circular body is placed at the center. The vertical walls of the cavity are kept thermally insulated, and... more
The physical model considered here is a lid-driven enclosure with bottom heating and top cooling conditions, and a heat generating circular body is placed at the center. The vertical walls of the cavity are kept thermally insulated, and the top lid moves at a constant speed. The steady two-dimensional governing equations for the physical problem are transformed in a dimensionless
Research Interests: Mechanical Engineering, Civil Engineering, Applied Mathematics, Computational Fluid Dynamics, Heat Transfer, and 13 moreFluid Dynamics, Finite Element, Mixed Convection, Fluid flow, Thermal Conductivity, Thermal Insulation, Drag Force, Nusselt Number, Galerkin Method, Physical Model, Reynolds Number, Transport Equation, and Parametric Study
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Research Interests:
In search of a new Prussian Blue analogue exhibiting fascinating magnetic properties, potassium manganese hexacyanoferrate, K0.2Mn0.66IIMn1.44III[Fe0.2IIFe0.8III(CN)6]O0.66(CH3COO)1.32], 7.6H2O, has been synthesized. This compound... more
In search of a new Prussian Blue analogue exhibiting fascinating magnetic properties, potassium manganese hexacyanoferrate, K0.2Mn0.66IIMn1.44III[Fe0.2IIFe0.8III(CN)6]O0.66(CH3COO)1.32], 7.6H2O, has been synthesized. This compound undergoes a paramagnetic to ferrimagnetic transition at 10K. Temperature and magnetic field-dependent magnetization studies of this compound have revealed different spin alignments below and above 3K. The nature of possible magnetic interactions between the nearest neighbor magnetic centers has been discussed in order to explore the origin of the observed magnetic interactions. Mössbauer spectroscopic study at different temperatures demonstrates the presence of both FeIII and FeII in low-spin states in this compound. Quantitative analysis of the FeIII and FeII ions, and their temperature dependence exhibits the existence of an electron transfer phenomenon between Mn and Fe ions [FeIII (t2g5, S=1/2)–CN–MnII (t2g3eg2, S=5/2)]⇔[FeII (t2g6, S=0)–CN–MnIII (t2g3eg1, S=2)]. This electron transfer has been remarkably enhanced in the magnetically ordered region.
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The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg... more
The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg rake angle, which appeared to have been made arbitrarily without any advantage. We have attempted to design a surgical drill bit with the objective of minimization of the drilling thrust and temperature and effective removal of bone chips. Our results showed that the presence of the chisel edge was mainly responsible for increasing the thrust force and the temperature developed. The effects of a constant feed rate and thrust on the peak temperature were also examined. The combined effect of the helix and the point angles on the rake angle which in turn determines the cutting efficiency was analyzed for various types of surgical bits. Based on our results and previously published data from the literature an optimized drill bit was designed with a split point, a point angle of 118 deg, a parabolic flute, and a helix angle of 36 deg and its performance was compared with other existing surgical drill bits. For drilling in compact bone, the new design decreased the thrust load by 45 percent an the peak temperature rise by 41 percent. Similar improvements were also recorded for drilling bone cement. The time of drilling a bone cortex was also significantly reduced and &quot;walking&quot; on the curved bone surface was eliminated and dimensional tolerance on hole sizes was improved. The new design is likely to reduce the time of surgery and also minimize the tissue damage.
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Research Interests:
Research Interests: Engineering, Magnetic Materials, Applied Physics, Nanocrystalline Material, Mathematical Sciences, and 12 morePhysical sciences, Magnetic Properties, Data storage, Iron, Thermal Stability, Thermal Decomposition, Magnetic Anisotropy, Nanostructured Material, Chemical Synthesis, Aspect Ratio, Fine Particles, and Magnetic Fluid
The main objective of this article is to study numerically a two-dimensional, steady and laminar viscous incompressible flow in a sinusoidal corrugated inclined enclosure. In this analysis, two vertical sinusoidal corrugated walls are... more
The main objective of this article is to study numerically a two-dimensional, steady and laminar viscous incompressible flow in a sinusoidal corrugated inclined enclosure. In this analysis, two vertical sinusoidal corrugated walls are maintained at a constant low temperature whereas a constant heat flux source whose length is varied from 20 to 80% of the total length of the enclosure is discretely embedded at the bottom wall. The Penalty finite element method has been used to solve the governing Navier–Stokes and energy ...
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Research Interests:
Research Interests:
Research Interests:
The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use... more
The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use of combination of surface temperature and NDVI which provides vegetation and moisture conditions simultaneously. Since drought stress effects on agriculture are closely linked to actual evapotranspiration, we used a vegetation temperature condition index (VTCI) which is more closely related to crop water status and holds a key place in real-time drought monitoring and assessment. In this study, NDVI and land surface temperature (T s) from MODIS 8-day composite data during cloud-free period (September–October) were adopted to construct an NDVI–T s space, from which the VTCI was computed. The crop moisture index (based on estimates of potential evapotranspiration and soil moisture depletion) was calculated to represent soil moisture stress on weekly basis for 20 weather monitoring stations. Correlation and regression analysis were attempted to relate VTCI with crop moisture status and crop performance. VTCI was found to accurately access the degree and spatial extent of drought stress in all years (2000, 2002, and 2004). The temporal variation of VTCI also provides drought pattern changes over space and time. Results showed significant and positive relations between CMI (crop moisture index) and VTCI observed particularly during prominent drought periods which proved VTCI as an ideal index to monitor terminal drought at regional scale. VTCI had significant positive relationship with yield but weakly related to crop anomalies. Duration of terminal drought stress derived from VTCI has a significant negative relationship with yields of major grain and oilseeds crops, particularly, groundnut.