722 research outputs found
Spectrophotometric estimation of nitro tyrosine by azo-coupling reaction
3-Nitrotyrosine has been identified using techniques like immunohistochemistry, HPLC, GCMS to demonstrate as a relevant biomarker in various disorders such as neurological, cardiovascular and others. Estimation of 3-NT by spectrophotometric method has been performed to measure 3-NT over decades. However none of the above methods have been translated to diagnose the diseases, but pathological conditions. Therefore here is an attempt to develop a method to be employed as a diagnostic tool. Current work is focussed on including preparation of 3-NT and further to derivatives using β-Napthol to yield diazotised product. All these intermediates of diazotized products have been characterized by ESI MS and the final colored dye was measured spectrophotometrically which exhibits λ max at 551 nm. The dye has been measured and compared with the direct measurement of 3-NT. The sensitivity of measurement of 3-NT increases by 10 fold, by and large we can estimate 20 μM concentration of 3-NT
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Computational estimation of scene structure through texture gradient cues
Analyzing the depth structure implied in two-dimensional images is one of the most active research areas in computer vision. Here, we propose a method of utilizing texture within an image to derive its depth structure. Though most approaches for deriving depth from a single still image utilize luminance edges and shading to estimate scene structure, relatively little work has been done to utilize the abundant texture information in images. Our new approach begins by analyzing the two cues of local spatial frequency and orientation distributions of the textures within an image, which are used to compute the local slant information across the image. The slant and frequency information are merged to create a unified depth map, providing an important channel for image structure information that can be combined with other available cues. The capabilities of the algorithm are illustrated for a variety of images of planar and curved surfaces under perspective projection, in most of which the depth structure is effortlessly perceived by human observers. Since these operations are readily implementable in neural hardware in early visual cortex, they therefore represent a model of the human perception of the depth structure of images from texture gradient cues
Sandifer syndrome: the mis-interpretable disorder
Sandifer syndrome (SS), a movement disorder which is characterised by spasmodic torsional dystonia with back arching and rigid opisthotonic posturing, negatively impacting predominantly the neck, back, and upper extremities. Symptomatic gastro-esophageal reflux disease, esophagitis, or the presence of a hiatal hernia are all associated with Sandifer syndrome. The cause of Sandifer syndrome being uncertain, lifestyle adjustments and modifications highlights as the appropriate mode of treatment. To treat the condition and help relax the baby after feeding, dietary changes or medications can be administered. The case report of a patient with Sandifer Syndrome is considered for observation. Upon arrival, the child was stable, and an Electro-encephalogram (EEG) test revealed nothing abnormal. The child was taking several Anti-epileptic drugs (AED’s), which were stopped in favour of Sodium valproate and Pyridoxine. An opinion from a Gastro-enterologist was sought in light of the epilepsy and possible Gastro-esophageal reflux disease (GERD), and they suggested a milk scan. Rantac was then started, and breastfeeds were thickened. Milk can indicate mild GERD and a reduction in episode frequency. So, sodium valproate was discontinued. Haemodynamically stable child was discharged from the hospital with Pyridoxine and Carnisure. Studies shows most cases of SS improve over time, within the first 24 months in general.
A domino palladium catalysis: Synthesis of 7-methyl-5 H -dibenzo[ a, c ][7] annulen-5-ones
A domino Pd-catalyzed reaction of 1-(2-bromophenyl)ethanones for the synthesis of novel 7-methyl-5H-dibenzo[a,c][7]annulen-5-ones, a carbon core structure present in colchicinoid natural products, is presented. The reaction is proposed to proceed via intermolecular homobiaryl coupling and intramolecular aldol condensatio
Formation of bi-aryls via a domino palladium catalysis
Synthesis of bi-aryls via a domino Pd-catalyzed reaction of 1-(2-bromophenyl)-2-methylpropan-1-ones/(2-bromophenyl)(cyclohexyl)methanones is presented. The mechanism of the reaction is believed to proceed through a five membered palladacycle that combines with a second molecule of halo-arene to yield the bi-aryls. This method is quite successful to deliver highly sterically crowded bi-aryls with dense functionalities on the aromatic rings
Palladium-catalyzed selective α-arylation of ortho -bromoacetophenones
Synthesis of 1-(2-bromophenyl)-2-phenylethanones via an intermolecular Pd-catalyzed α-arylation of 1-(2-bromophenyl)ethanones is presented. The method relies on selective C-H activation (α-arylation) of relatively more reactive external iodo-arenes as coupling partners without affecting the bromo-substituent. Moreover, the scope and generality of the method has been well studied by employing the reaction with iodo-arenes as coupling partners bearing electron-withdrawing, simple, and electron-donating groups on the aromatic ring
Interferon-γ Added During Bacillus Calmette-Guerin Induced Dendritic Cell Maturation Stimulates Potent T(h)1 Immune Responses
Dendritic cells (DC) are increasingly prepared in vitro for use in immunotherapy trials. Mature DC express high levels of surface molecules needed for T cell activation and are superior at antigen-presentation than immature DC. Bacillus Calmette-Guerin (BCG) is one of several products known to induce DC maturation, and interferon (IFN)-γ has been shown to enhance the activity of DC stimulated with certain maturation factors. In this study, we investigated the use of IFN-γ in combination with the powerful maturation agent, BCG. The treatment of immature DC with IFN-γ plus BCG led to the upregulation of CD54, CD80, and CD86 in comparison with BCG treatment alone. In MLR or recall immune responses, the addition of IFN-γ at the time of BCG-treatment did not increase the number of antigen-specific T cells but enhanced the development of IFN-γ-producing Th1 cells. In primary immune responses, on the other hand, BCG and IFN-γ co-treated DC stimulated higher proportions of specific T cells as well as IFN-γ secretion by these T cells. Thus the use of IFN-γ during BCG-induced DC maturation differentially affects the nature of recall versus naïve antigen-specific T-cell responses. IFN-γ co-treatment with BCG was found to induce IL-12 and, in some instances, inhibit IL-10 secretion by DC. These findings greatly enhance the potential of BCG-matured dendritic cells for use in cancer immunotherapy
Permanent His Bundle Pacing: Electrophysiological and Echocardiographic Observations From Long-Term Follow-Up
Background
Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. It is not known whether HBP can cause His-Purkinje conduction (HPC) disease. The aim of our study is to assess His bundle capture and its effect on left ventricular (LV) function in long-term follow-up and to determine HPC at the time of pulse generator change (GC) in patients with chronic HBP.
Methods
HB electrograms were recorded from the pacing lead at implant and GC. HBP QRS duration (QRSd), His-ventricular (HV) intervals, and HB pacing thresholds at GC were compared with implant measurements. HPC was assessed by pacing at cycle lengths of 700 ms, 600 ms, and 500 ms at GC. LV internal diameters, ejection fraction (EF), and valve dysfunction at baseline were compared with echocardiography during follow-up.
Results
GC was performed in 20 patients (men 13; age 74 ± 14 years) with HBP at 70 ± 24 months postimplant. HV intervals remained unchanged from initial implant (44 ± 4 ms vs 45 ± 4 ms). During HBP at 700 ms, 600 ms, and 500 ms (n = 17), consistent 1:1 HPC was present. HBP QRSd remained unchanged during follow-up (117 ± 20 ms vs 118 ± 23 ms). HBP threshold at implant and GC was 1.9 ± 1.1 V and 2.5 ± 1.2 V @ 0.5 ms. Despite high pacing burden (77 ± 13%), there was no significant change in LVEF (50 ± 14% at implant) during follow-up (55 ± 6%, P = 0.06).
Conclusions
HBP does not appear to cause new HPC abnormalities and is associated with stable HBP QRSd during long-term follow-up. Despite high pacing burden, HBP did not result in deterioration of left ventricular systolic function or cause new valve dysfunction
Polishing of CVD-Diamond Substrates Using Reactive Ion Etching
Multichip modules (MCM)have proved to be a viable packaging technology for achieving small size and high performance. By their nature, MCMs typically integrate multiple bare die into a module that can be the plastic or ceramic package. As a result, the MCMrequires an efficient mechanism for removing excess heat. Diamond with its excellent thermal conductivity, is the ideal choice as a substrate material for these applications. Chemical vapor deposited (CVD) diamond substrates makes possible the practical realization of a novel diamond based 3-D MCM. However, the diamond films grown by CVD technique are polycrystalline and have non-uniform filmroughness and randomly faceted crystals. These non-planar surfaces reduce the diamond\u27s thermal management efficiency. Therefore, itbecomes imperative that the asdeposited diamond films be polished for use inMCMs. Chemical assisted mechanical polishing (CAMP) technique has been developed at HiDEC,University of Arkansas. In this technique diamond is lapped against an alumina plate under a load in the presence of certain chemicals. Although CAMP technique reduces the lapping time considerably, stillnewer techniques must be developed to reduce polishing cost further. We are currently using reactive ion etching (RIE) to substantially reduce the polishing time. Preliminary studies using reactive ion etching showed etch rates of 500 - lOOOA/min at low pressures. These etched films showed a considerably higher polishing rate (using CAMP technique) than the nonetched films. Changes in the morphology and structure of the diamond films due to etching and polishing were characterized by scanning electron microscopy (SEM), Dektak profilometer and Raman spectroscopy. This paper presents a systematic study ofRIEand CAMP of CVD-diamond substrates
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