2,940 research outputs found

    Surface Modification of TiO2 Nanoparticles with Phenyltrimethoxysilane in Dye-sensitized Solar Cells

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    Phenyltrimethoxysilane (PTMS) was anchored onto the sensitized TiO2 nanoparticles. This insulating molecular layer effectively inhibited the charge recombination at the interface of TiO2/electrolyte in the dye sensitized solar cells (DSCs) without sacrificing the dye-loading capacity of the nanocrystalline TiO2. DSCs using PTMS-modified TiO2 exhibited a short-circuit current (J(SC)) of 15.9 mA/cm(2), an open-circuit voltage (V-OC) of 789 mV, and a fill factor (FE) of 68.2%, yielding an overall conversion efficiency (eta) of 8.55% under 100 mW/cm(2) illumination. The resulting cell efficiency was improved by similar to 10% as compared with the reference cell.X1133Ysciescopu

    Technical performance and diagnostic utility of the new Elecsys (R) neuron-specific enolase enzyme immunoassay

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    This international multicenter study was designed to evaluate the technical performance of the new double-monoclonal, single-step Elecsys neuron-specific enolase (NSE) enzyme immunoassay (EIA) and to assess its utility as a sensitive and specific test for the diagnosis of small-cell lung cancer (SCLC). Intra and interassay coefficients of variation, determined in five control or serum specimens in six laboratories, ranged from 0.7 to 5.3 (interlaboratory median: 1.3%) and from 1.3 to 8.5 (interlaboratory median: 3.4%), respectively. Laboratory-to-laboratory comparability was excellent with respect to recovery and interassay coefficients of variation. The test was linear between 0.0 and 320 ng/ml (highest measured concentration). There was a significant correlation between NSE concentrations measured using the Elecsys NSE and the established Cobas Core NSE EIA II in all subjects (n=723) and in patients with lung cancer (n=333). However, NSE concentrations were systematically lower (approximately 9%) with the Elecsys NSE than with the comparison test. Based on a specificity of 95% in comparison with the group suffering from benign lung diseases (n=183), the cutoff value for the discrimination between malignant and benign conditions was set at 21.6 ng/ml. NSE was raised in 73.4% of SCLC patients (n=188) and was significantly higher (p<0.01) in extensive (87.8%) as opposed to limited disease (56.7%). NSE was also elevated in 16.0% of the cases with non-small cell lung cancer (NSCLC, n=374). It is concluded that the Elecsys NSE EIA is a reliable and accurate diagnostic procedure for the measurement of NSE in serum samples. The special merits of this new assay are the wide measuring range (according to manufacturers declaration up to 370 ng/ml) and a short incubation time of 18 min

    Current THD and Output Voltage Ripple Characteristics of Flyback PFC Converters with LED Lamp and Nonlinear RL Loads

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    This study analysed the characteristics of total harmonic distortion (THD) and output voltage ripple in a flyback PFC converter circuit under two different loads, which are the LED lamp modules and nonlinear RL loads. The converter was designed to step down the AC input voltage (90 V-265 V) to a DC output voltage of 80 V DC for both loads, each with an output power of 16 W. The main objectives were to observe and assess current THD and output voltage ripple for both loads using two different capacitances of the output capacitor, which are 2400 μF and 6 μF, respectively. The results demonstrated that using smaller capacitors (6 μF), it increased output voltage ripple, which it increased for the LED lamp load from 10% to 25% and for the nonlinear RL load it increased from 15% to 70%. However, with the same smaller capacitors (6 μF), it reduced current THD for both loads, which for the LED lamp load it reduced from 12% to 10.3%, and for the nonlinear RL load it reduced from 13.7% to 8.3%. From these results, with 2400 μF of the output capacitor, it provided better performance in terms of current THD and output voltage ripple for both load types.

    Current THD and Output Voltage Ripple Characteristics of Flyback PFC Converters with LED Lamp and Nonlinear RL Loads

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    This study analysed the characteristics of total harmonic distortion (THD) and output voltage ripple in a flyback PFC converter circuit under two different loads, which are the LED lamp modules and nonlinear RL loads. The converter was designed to step down the AC input voltage (90 V-265 V) to a DC output voltage of 80 V DC for both loads, each with an output power of 16 W. The main objectives were to observe and assess current THD and output voltage ripple for both loads using two different capacitances of the output capacitor, which are 2400 μF and 6 μF, respectively. The results demonstrated that using smaller capacitors (6 μF), it increased output voltage ripple, which it increased for the LED lamp load from 10% to 25% and for the nonlinear RL load it increased from 15% to 70%. However, with the same smaller capacitors (6 μF), it reduced current THD for both loads, which for the LED lamp load it reduced from 12% to 10.3%, and for the nonlinear RL load it reduced from 13.7% to 8.3%. From these results, with 2400 μF of the output capacitor, it provided better performance in terms of current THD and output voltage ripple for both load types.

    Anodic-oxide-induced intermixing in GaAs-AlGaAs quantum-well and quantum-wire structures

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    Anodic oxides of GaAs were shown to enhance the intermixing in GaAs-AlGaAs quantum wells (QW) during rapid thermal processing. Proximity of the anodic oxide to the QW has been shown to influence the photoluminescence (PL) energy shift due to intermixing. Anodic oxide induced intermixing has been used to enhance quantum-wire PL in the structures grown on V-groove patterned GaAs substrates. This has been attributed to enhanced lateral confinement in these structures. Injection of defects such as group-III vacancies or interstitials was considered to be driving force for the intermixing.published_or_final_versio

    SMARCB1 Gene Therapy Using a Novel Tumor-Targeted Nanomedicine Enhances Anti-Cancer Efficacy in a Mouse Model of Atypical Teratoid Rhabdoid Tumors

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    Sang-Soo Kim,1,2 Manish Moghe,1 Antonina Rait,1 Kathryn Donaldson,1 Joe B Harford,2 Esther H Chang1 1Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, USA; 2SynerGene Therapeutics, Inc, Potomac, MD, USACorrespondence: Esther H Chang, Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road N.W., Research Building E420, Washington, DC, 20057, USA, Email [email protected]: Atypical teratoid rhabdoid tumor (ATRT) is a deadly, fast-growing form of pediatric brain cancer with poor prognosis. Most ATRTs are associated with inactivation of SMARCB1, a subunit of the chromatin remodeling complex, which is involved in developmental processes. The recent identification of SMARCB1 as a tumor suppressor gene suggests that restoration of SMARCB1 could be an effective therapeutic approach.Methods: We tested SMARCB1 gene therapy in SMARCB1-deficient rhabdoid tumor cells using a novel tumor-targeted nanomedicine (termed scL-SMARCB1) to deliver wild-type SMARCB1. Our nanomedicine is a systemically administered immuno-lipid nanoparticle that can actively cross the blood-brain barrier via transferrin receptor-mediated transcytosis and selectively target tumor cells via transferrin receptor-mediated endocytosis. We studied the antitumor activity of the scL-SMARCB1 nanocomplex either as a single agent or in combination with traditional treatment modalities in preclinical models of SMARCB1-deficient ATRT.Results: Restoration of SMARCB1 expression by the scL-SMARCB1 nanocomplex blocked proliferation, and induced senescence and apoptosis in ATRT cells. Systemic administration of the scL-SMARCB1 nanocomplex demonstrated antitumor efficacy as monotherapy in mice bearing ATRT xenografts, where the expression of exogenous SMARCB1 modulates MYC-target genes. scL-SMARCB1 demonstrated even greater antitumor efficacy when combined with either cisplatin-based chemotherapy or radiation therapy, resulting in significantly improved survival of ATRT-bearing mice.Conclusion: Collectively, our data suggest that restoring SMARCB1 function via the scL-SMARCB1 nanocomplex may lead to therapeutic benefits in ATRT patients when combined with traditional chemoradiation therapies. Keywords: lipid nanoparticle, nanodelivery, SMARCB1, gene therapy, atypical teratoid rhabdoid tumo

    Modeling and improving the output power of terahertz master-oscillator power-amplifier quantum cascade lasers

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    A model based on carrier rate equations is proposed to evaluate the gain saturation and predict the dependence of the output power of a terahertz master-oscillator power-amplifier quantum cascade laser (THz-MOPA-QCL) on the material and structure parameters. The model reveals the design rules of the preamplifier and the power extractor to maximize the output power and the wall-plug efficiency. The correction of the model is verified by its agreement with the experiment results. The optimized MOPA devices exhibit single-mode emission at ∼ 2.6 THz with a side mode suppression ratio of 23 dB, a pulsed output power of 153 mW, a wall-plug efficiency of 0.22%, and a low divergence angle of ∼6°×16°, all measured at an operation temperature of 77 K. The model developed here is helpful for the design of MOPA devices and semiconductor optical amplifiers, in which the active region is based on intersubband transitions

    Orbital textures and charge density waves in transition metal dichalcogenides

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    Low-dimensional electron systems, as realized naturally in graphene or created artificially at the interfaces of heterostructures, exhibit a variety of fascinating quantum phenomena with great prospects for future applications. Once electrons are confined to low dimensions, they also tend to spontaneously break the symmetry of the underlying nuclear lattice by forming so-called density waves; a state of matter that currently attracts enormous attention because of its relation to various unconventional electronic properties. In this study we reveal a remarkable and surprising feature of charge density waves (CDWs), namely their intimate relation to orbital order. For the prototypical material 1T-TaS2 we not only show that the CDW within the two-dimensional TaS2-layers involves previously unidentified orbital textures of great complexity. We also demonstrate that two metastable stackings of the orbitally ordered layers allow to manipulate salient features of the electronic structure. Indeed, these orbital effects enable to switch the properties of 1T-TaS2 nanostructures from metallic to semiconducting with technologically pertinent gaps of the order of 200 meV. This new type of orbitronics is especially relevant for the ongoing development of novel, miniaturized and ultra-fast devices based on layered transition metal dichalcogenides

    Blow-up profile of rotating 2D focusing Bose gases

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    We consider the Gross-Pitaevskii equation describing an attractive Bose gas trapped to a quasi 2D layer by means of a purely harmonic potential, and which rotates at a fixed speed of rotation Ω\Omega. First we study the behavior of the ground state when the coupling constant approaches a_a\_* , the critical strength of the cubic nonlinearity for the focusing nonlinear Schr{\"o}dinger equation. We prove that blow-up always happens at the center of the trap, with the blow-up profile given by the Gagliardo-Nirenberg solution. In particular, the blow-up scenario is independent of Ω\Omega, to leading order. This generalizes results obtained by Guo and Seiringer (Lett. Math. Phys., 2014, vol. 104, p. 141--156) in the non-rotating case. In a second part we consider the many-particle Hamiltonian for NN bosons, interacting with a potential rescaled in the mean-field manner a_NN2β1w(Nβx),with--a\_N N^{2\beta--1} w(N^{\beta} x), with wapositivefunctionsuchthat a positive function such that \int\_{\mathbb{R}^2} w(x) dx = 1.Assumingthat. Assuming that \beta < 1/2andthat and that a\_N \to a\_*sufficientlyslowly,weprovethatthemanybodysystemisfullycondensedontheGrossPitaevskiigroundstateinthelimit sufficiently slowly, we prove that the many-body system is fully condensed on the Gross-Pitaevskii ground state in the limit N \to \infty$

    International Veterinary Epilepsy Task Force consensus report on epilepsy definition, classification and terminology in companion animals

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    Dogs with epilepsy are among the commonest neurological patients in veterinary practice and therefore have historically attracted much attention with regard to definitions, clinical approach and management. A number of classification proposals for canine epilepsy have been published during the years reflecting always in parts the current proposals coming from the human epilepsy organisation the International League Against Epilepsy (ILAE). It has however not been possible to gain agreed consensus, “a common language”, for the classification and terminology used between veterinary and human neurologists and neuroscientists, practitioners, neuropharmacologists and neuropathologists. This has led to an unfortunate situation where different veterinary publications and textbook chapters on epilepsy merely reflect individual author preferences with respect to terminology, which can be confusing to the readers and influence the definition and diagnosis of epilepsy in first line practice and research studies. In this document the International Veterinary Epilepsy Task Force (IVETF) discusses current understanding of canine epilepsy and presents our 2015 proposal for terminology and classification of epilepsy and epileptic seizures. We propose a classification system which reflects new thoughts from the human ILAE but also roots in former well accepted terminology. We think that this classification system can be used by all stakeholders
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