1,212 research outputs found

    The N-Terminus of Apolipoprotein A-V Adopts a Helix-Bundle Molecular Architecture

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    Previous studies of recombinant full-length human apolipoprotein A-V (apoA-V) provided evidence of the presence of two independently folded structural domains. Computer-assisted sequence analysis and limited proteolysis studies identified an N-terminal fragment as a candidate for one of the domains. C-Terminal truncation variants in this size range, apoA-V(1-146) and apoA-V(1-169), were expressed in Escherichia coli and isolated. Unlike full-length apoA-V or apoA-V(1-169), apoA-V(1-146) was soluble in neutral-pH buffer in the absence of lipid. Sedimentation equilibrium analysis yielded a weight-average molecular weight of 18811, indicating apoA-V(1-146) exists as a monomer in solution. Guanidine HCl denaturation experiments at pH 3.0 yielded a one-step native to unfolded transition that corresponds directly with the more stable component of the two-stage denaturation profile exhibited by full-length apoA-V. On the other hand, denaturation experiments conducted at pH 7.0 revealed a less stable structure. In a manner similar to that of known helix bundle apolipoproteins, apoA-V(1-146) induced a relatively small enhancement in 8-anilino-1-naphthalenesulfonic acid fluorescence intensity. Quenching studies with single-Trp apoA-V(1-146) variants revealed that a unique site predicted to reside on the nonpolar face of an amphipathic R-helix was protected from quenching by KI. Taken together, the data suggest the 146 N-terminal residues of human apoA-V adopt a helix bundle molecular architecture in the absence of lipid and, thus, likely exist as an independently folded structural domain within the context of the intact protein

    Adaptive Impedance Tuning Network using Genetic Algorithm: ITuneGA

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    Adaptive impedance tuning algorithms are used to preserve the link quality of mobile phones under fluctuating user conditions. It is highly desirable to correct the complex impedance mismatch with high convergence rate. Presented here, is a novel technique for correcting impedance mismatch in adaptive impedance tuning network by exploiting the relationships among the genetic algorithm’s coefficient values derived from the matching network parameters. Simulation results demonstrate that the proposed impedance tunable algorithm (ITuneGA) outperforms conventional GA and LMS, with its fast convergence speed and high accuracy. The robustness of ITuneGA has been verified by using Pi-networks with two and four tuning elements. ITuneGA corrects antenna impedance mismatches and reduces the reflected power, thereby significantly improving the quality of the signal

    Approximate Solution of the effective mass Klein-Gordon Equation for the Hulthen Potential with any Angular Momentum

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    The radial part of the effective mass Klein-Gordon equation for the Hulthen potential is solved by making an approximation to the centrifugal potential. The Nikiforov-Uvarov method is used in the calculations. Energy spectra and the corresponding eigenfunctions are computed. Results are also given for the case of constant mass.Comment: 12 page

    Notes on some plant collections from Bachok and several forest reserves in Kelantan

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    A botanical survey of Bachok and various forest reserves at Jeram Linang, Jeram Pasu and Bukit Bakar was part of an expedition from 14–20 June 2008 carried out by the IOES (Institute of Ocean and Earth Sciences) University of Malaya to survey and prepare an inventory of the biodiversity of the coastal region around Bachok, Kelantan. A total of 54 species from 30 families, consisting of seashore and mangrove plants were identified from the coastal area of Bachok and Semerak; while 89 species of flowering plants representing 44 families, a single gymnosperm, Agathis borneensis (Araucariaceae); and 15 genera and 23 species of mosses (from 10 families) were recorded in the three forest reserves. Several of the species collected were rarely found outside Kelantan. Satu survei tumbuhan di Bachok dan beberapa hutan simpanan termasuk Jeram Linang, Jeram Pasu dan Bukit Bakar, Kelantan adalah sebahagian ekspedisi survei biodiversiti kawasan pantai di sekitar Bachok Kelantan oleh IOES (Institute of Ocean and Earth Sciences) Universiti Malaya pada 14–20 Jun 2008. Sejumlah 54 spesies daripada 30 famili tumbuhan pantai dan bakau dikenalpasti dari kawasan pantai Bachok dan Semerak; sedangkan 89 spesies tumbuhan berbunga (mewakili 44 famili), satu gimnosperma, Agathis borneensis (Araucariaceae); serta 15 genera dan 23 spesies daripada 10 famili lumut sejati telah direkodkan di kawasan sekitar Jeram Linang, Jeram Pasu dan Hutan Lipur Bukit Bakar. Beberapa spesies yang dikutip adalah jarang ditemui di luar Kelantan

    Denosumab, raloxifene, romosozumab and teriparatide to prevent osteoporotic fragility fractures: a systematic review and economic evaluation

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    Background Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture. Objectives The objectives were to evaluate the clinical effectiveness, safety and cost-effectiveness of non-bisphosphonates {denosumab [Prolia®; Amgen Inc., Thousand Oaks, CA, USA], raloxifene [Evista®; Daiichi Sankyo Company, Ltd, Tokyo, Japan], romosozumab [Evenity®; Union Chimique Belge (UCB) S.A. (Brussels, Belgium) and Amgen Inc.] and teriparatide [Forsteo®; Eli Lilly and Company, Indianapolis, IN, USA]}, compared with each other, bisphosphonates or no treatment, for the prevention of fragility fracture. Data sources For the clinical effectiveness review, nine electronic databases (including MEDLINE, EMBASE and the World Health Organization International Clinical Trials Registry Platform) were searched up to July 2018. Review methods A systematic review and network meta-analysis of fracture and femoral neck bone mineral density were conducted. A review of published economic analyses was undertaken and a model previously used to evaluate bisphosphonates was adapted. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years for a simulated cohort of patients with heterogeneous characteristics. This was done for each non-bisphosphonate treatment, a strategy of no treatment, and the five bisphosphonate treatments previously evaluated. The model was populated with effectiveness evidence from the systematic review and network meta-analysis. All other parameters were estimated from published sources. An NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net monetary benefit was estimated using non-parametric regression. A probabilistic sensitivity analysis and scenario analyses were used to assess uncertainty. Results Fifty-two randomised controlled trials of non-bisphosphonates were included in the clinical effectiveness systematic review and an additional 51 randomised controlled trials of bisphosphonates were included in the network meta-analysis. All treatments had beneficial effects compared with placebo for vertebral, non-vertebral and hip fractures, with hazard ratios varying from 0.23 to 0.94, depending on treatment and fracture type. The effects on vertebral fractures and the percentage change in bone mineral density were statistically significant for all treatments. The rate of serious adverse events varied across trials (0–33%), with most between-group differences not being statistically significant for comparisons with placebo/no active treatment, non-bisphosphonates or bisphosphonates. The incremental cost-effectiveness ratios were > £20,000 per quality-adjusted life-year for all non-bisphosphonate interventions compared with no treatment across the range of QFracture and FRAX scores expected in the population eligible for fracture risk assessment. The incremental cost-effectiveness ratio for denosumab may fall below £30,000 per quality-adjusted life-year at very high levels of risk or for high-risk patients with specific characteristics. Raloxifene was dominated by no treatment (resulted in fewer quality-adjusted life-years) in most risk categories. Limitations The incremental cost-effectiveness ratios are uncertain for very high-risk patients. Conclusions Non-bisphosphonates are effective in preventing fragility fractures, but the incremental cost-effectiveness ratios are generally greater than the commonly applied threshold of £20,000–30,000 per quality-adjusted life-year. Study registration This study is registered as PROSPERO CRD42018107651. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 29. See the NIHR Journals Library website for further project information

    A high-flux source of polarization-entangled photons from a periodically-poled KTP parametric downconverter

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    We have demonstrated a high-flux source of polarization-entangled photons using a type-II phase-matched periodically-poled KTP parametric downconverter in a collinearly propagating configuration. We have observed quantum interference between the single-beam downconverted photons with a visibility of 99% and a measured coincidence flux of 300/s/mW of pump. The Clauser-Horne-Shimony-Holt version of Bell's inequality was violated with a value of 2.711 +/- 0.017.Comment: 7 pages submitted to Physical Review

    Dickson Charge Pump Rectifier using Ultra-Low Power (ULP) Diode for BAN Applications

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    High power consumption and small battery size severely limit the operating time of devices in Body Area Network (BAN). Radio Frequency (RF) harvesting system can be one of the ways to solve this constraint. Rectifier converts ambient RF into direct current (DC). In a conventional rectifier circuit, Schottky diodes have been considered as an attractive candidate due to their low forward voltage drop and fast switching speed. However, Schottky diodes are not properly modelled in Complementary Metal Oxide Semiconductor (CMOS) technologies which restrict their usefulness in low -cost applications, where high integration levels are desired. Thus, an efficient model of Schottky diode in an integrated circuit (IC) domain is needed. For this reason, Ultra-Low Power (ULP) diode has been proposed in the IC rectifier designs. The performance of ULP diode was compared with diode-connected MOSFET based on Dickson topology and Villard voltage multiplier in 130nm Silterra process technology. The correlation of the design parameters to the performance of voltage rectifier was analysed. The results show that the efficiency of the voltage multiplier has successfully increased more than double based on the optimisation of the design parameters

    A bizarre case of accessory larynx in an infant with OEIS syndrome

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    We report a bizarre case of accessory larynx in an infant with OEIS syndrome (omphalocele, cloacal exstrophy, imperforated anus & spinal defects). This is the first reported case in literature of a duplicate accessory larynx which is a mirror image of the true larynx. A congenital duplication of the larynx is a rare anomaly and can present in various forms. In this case, the infant presented with recurrent lung infection and inability to wean off oxygen. Scope revealed severe laryngomalacia in addition to the accessory larynx. Hence, supraglottoplasty was done with aim to resolve the lung and airway problem

    Emotional valence and arousal affect reading in an interactive way: neuroimaging evidence for an approach-withdrawal framework

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    A growing body of literature shows that the emotional content of verbal material affects reading, wherein emotional words are given processing priority compared to neutral words. Human emotions can be conceptualised within a two-dimensional model comprised of emotional valence and arousal (intensity). These variables are at least in part distinct, but recent studies report interactive effects during implicit emotion processing and relate these to stimulus-evoked approach-withdrawal tendencies. The aim of the present study was to explore how valence and arousal interact at the neural level, during implicit emotion word processing. The emotional attributes of written word stimuli were orthogonally manipulated based on behavioural ratings from a corpus of emotion words. Stimuli were presented during an fMRI experiment while 16 participants performed a lexical decision task, which did not require explicit evaluation of a word's emotional content. Results showed greater neural activation within right insular cortex in response to stimuli evoking conflicting approach-withdrawal tendencies (i.e., positive high-arousal and negative low-arousal words) compared to stimuli evoking congruent approach vs. withdrawal tendencies (i.e., positive low-arousal and negative high-arousal words). Further, a significant cluster of activation in the left extra-striate cortex was found in response to emotional than neutral words, suggesting enhanced perceptual processing of emotionally salient stimuli. These findings support an interactive two-dimensional approach to the study of emotion word recognition and suggest that the integration of valence and arousal dimensions recruits a brain region associated with interoception, emotional awareness and sympathetic functions
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