299 research outputs found
Camera stabilizer
In the world of videography and cinematography, visible camera shake is a common thing. Visible camera shake usually is caused by the movement of the camera operator when using a camera. Camera stabilizer is a device used by many people to reduce or remove the visible camera shake to create better quality videos. Most camera stabilizers available in the global market uses advanced technologies that can stabilize a camera very easily. However, the use of advance technologies has caused a spike in the price of these camera stabilizers. There are very little to none option when it comes to a low-cost camera stabilizer available in the market. This project main purpose is to design and fabricate a low-cost camera stabilizer that would be affordable to more people from different walk of life. The low-cost camera stabilizer will use simple mechanism to stabilize a camera instead of advance technologies that are used on most high cost camera stabilizers. The result shows that this low-cost camera stabilizers were able to stabilize a camera and reduce the visible camera shake using the balancing mechanism
Effect of Multiple Quantum Well Periods on Structural Properties and Performance of Extended Short-Wavelength Infrared LEDs
We present research on the role of multiple quantum well periods in extended short-wavelength infrared InGaAs/InAsPSb type-I LEDs. The fabricated LEDs consisted of 6, 15, and 30 quantum well periods, and we evaluated the structural properties and device performance through a combination of theoretical simulations and experimental characterization. The strain and energy band offset was precisely controlled by carefully adjusting the composition of the InAsPSb quaternary material, achieving high valence and conduction band offsets of 350 meV and 94 meV, respectively. Our LEDs demonstrated a high degree of relaxation of 94-96 %. Additionally, we discovered that the temperature-dependent dark current characterization attributed to generation-recombination and trap-assign tunneling, with trap-assign tunneling being more dominant at lower current injections. Electroluminescence analysis revealed that the predominant emission mechanism of the LEDs originated from localized exciton and free exciton radiative recombination, which the 30 quantum wells LED exhibited the highest contribution of the localized exciton/free exciton radiative recombination. We observed that increasing the quantum well periods from 6 to 15 led to an increase in the 300 K electroluminescence intensity of the LED. However, extending the quantum well period to 30 resulted in a decline in emission intensity due to the degradation of the epitaxial film quality
Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification
The present study was aimed to investigate the effects of curcumin, a representative chemopreventive phytochemical with pronounced antioxidant and anti-inflammatory properties, on activation of Nrf2 and expression of its target protein heme oxygenase-1 (HO-1) in mouse skin in vivo and in cultured murine epidermal cells. Treatment of mouse epidermal JB6 cells with curcumin resulted in the induction of HO-1 expression, and this was abrogated in cells transiently transfected with Nrf2 siRNA. While curcumin treatment increased protein expression of Nrf2, it did not alter the steady-state level of the Nrf2 mRNA transcript. Treatment of cells with curcumin stabilized Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of this transcription factor. Tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the alpha,beta-unsaturated carbonyl group, failed to induce HO-1 expression as well as nuclear translocation of Nrf2 and its binding to the antioxidant/electrophile response elements. Cells transfected with a mutant Keap1 protein in which cysteine 151 (Cys151) is replaced by serine exhibited marked reduction in curcumin-induced Nrf2 transactivation. Mass spectrometric analysis revealed that curcumin binds to Keap1 Cys151, supporting that this amino acid is a critical target for curcumin modification of Keap1, which facilitates the liberation of Nrf2. Thus, it is likely that the alpha,beta-unsaturated carbonyl moiety of curcumin is essential for its binding to Keap1 and stabilization of Nrf2 by hampering ubiquitination and proteasomal degradation.
Factors Associated with HIV-1 Proviral DNA Loads in Patients with Undetectable Plasma RNA Load
To evaluate factors associated with human immunodeficiency virus type 1 (HIV-1) proviral DNA load, we conducted a cross-sectional study of 36 chronically HIV-1-infected individuals with undetectable plasma viral RNA. We used real-time polymerase chain reaction to determine the number of HIV-1 proviral DNA copies per 106 peripheral blood mononuclear cells. The mean level of plasma viral RNA when the CD4+ T cell count was above 500 cells/ĀµL without highly active antiretroviral therapy (HAART) was significantly associated with proviral DNA load at the time of undetectable plasma HIV RNA with HAART. Strategies to reduce the level of plasma viral RNA when patients' CD4+ T cell counts are above 500 cells/ĀµL without HAART could help reduce HIV-1 proviral DNA load
Performance evaluation of the HepB Typer-Entecavir kit for detection of entecavir resistance mutations in chronic hepatitis B
Background/AimsMolecular diagnostic methods have enabled the rapid diagnosis of drug-resistant mutations in hepatitis B virus (HBV) and have reduced both unnecessary therapeutic interventions and medical costs. In this study we evaluated the analytical and clinical performances of the HepB Typer-Entecavir kit (GeneMatrix, Korea) in detecting entecavir-resistance-associated mutations.MethodsThe HepB Typer-Entecavir kit was evaluated for its limit of detection, interference, cross-reactivity, and precision using HBV reference standards made by diluting high-titer viral stocks in HBV-negative human serum. The performance of the HepB Typer-Entecavir kit for detecting mutations related to entecavir resistance was compared with direct sequencing for 396 clinical samples from 108 patients.ResultsUsing the reference standards, the detection limit of the HepB Typer-Entecavir kit was found to be as low as 500 copies/mL. No cross-reactivity was observed, and elevated levels of various interfering substances did not adversely affect its analytical performance. The precision test conducted by repetitive analysis of 2,400 replicates with reference standards at various concentrations showed 99.9% agreement (2398/2400). The overall concordance rate between the HepB Typer-Entecavir kit and direct sequencing assays in 396 clinical samples was 99.5%.ConclusionsThe HepB Typer-Entecavir kit showed high reliability and precision, and comparable sensitivity and specificity for detecting mutant virus populations in reference and clinical samples in comparison with direct sequencing. Therefore, this assay would be clinically useful in the diagnosis of entecavir-resistance-associated mutations in chronic hepatitis B
Janus-faced Sestrin2 controls ROS and mTOR signalling through two separate functional domains
Sestrins are stress-inducible metabolic regulators with two seemingly unrelated but physiologically important functions: reduction of reactive oxygen species (ROS) and inhibition of the mechanistic target of rapamycin complex 1 (mTORC1). How Sestrins fulfil this dual role has remained elusive so far. Here we report the crystal structure of human Sestrin2 (hSesn2), and show that hSesn2 is twofold pseudo-symmetric with two globular subdomains, which are structurally similar but functionally distinct from each other. While the N-terminal domain (Sesn-A) reduces alkylhydroperoxide radicals through its helixāturnāhelix oxidoreductase motif, the C-terminal domain (Sesn-C) modified this motif to accommodate physical interaction with GATOR2 and subsequent inhibition of mTORC1. These findings clarify the molecular mechanism of how Sestrins can attenuate degenerative processes such as aging and diabetes by acting as a simultaneous inhibitor of ROS accumulation and mTORC1 activation
Simultaneous detection and subtyping of porcine endogenous retroviruses proviral DNA using the dual priming oligonucleotide system
The purpose of this study was to develop a multiplex PCR that can detect porcine endogenous retrovirus (PERV) proviral genes (pol, envA, envB, envC) and porcine mitochondrial DNA, using a dual priming oligonucleotide (DPO) system. The primer specifically detected the PERV proviral genes pol, envA, envB, envC, and porcine mitochondrial DNA only in samples of pig origin. The sensitivity of the primer was demonstrated by simultaneous amplification of all 5 target genes in as little as 10 pg of pig DNA containing PERV proviral genes and mitochondrial DNA. The multiplex PCR, when applied to field samples, simultaneously and successfully amplified PERV proviral genes from liver, blood and hair root samples. Thus, the multiplex PCR developed in the current study using DPO-based primers is a rapid, sensitive and specific assay for the detection and subtyping of PERV proviral genes
Intravascular Papillary Endothelial Hyperplasia (Masson's Hemangioma) of the Liver: A New Hepatic Lesion
Intravascular papillary endothelial hyperplasia (Masson's hemangioma) is a disease characterized by exuberant endothelial proliferation within the lumen of medium-sized veins. In 1923, Masson regarded this disease as a neoplasm inducing endothelial proliferation, however, now it is considered to be a reactive vascular proliferation following traumatic vascular stasis. The lesion has a propensity to occur in the head, neck, fingers, and trunk. Occurrence within the abdominal cavity is known to be very rare, and especially in the liver, there has been no reported case up to date. The authors have experienced intravascular papillary endothelial hyperplasia of the liver in a 69-yr-old woman, and report the case with a review of the literature
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