714 research outputs found
A Method of Analysis for Unequal Numbers of Replicates in a Factorial Experiment
9 pages, 1 article*A Method of Analysis for Unequal Numbers of Replicates in a Factorial Experiment* (Paik, U. B.) 9 page
A Generalized Procedure for Constructing Fractional Replicates
39 pages, 1 article*A Generalized Procedure for Constructing Fractional Replicates* (Paik, U. B.; Federer, W. T.) 39 page
On the Construction of Fractional Replicates with Special Reference to Saturated Designs
33 pages, 1 article*On the Construction of Fractional Replicates with Special Reference to Saturated Designs* (Paik, U. B.; Federer, W. T.) 33 page
MXene Analogue: A 2D Nitridene Solid Solution for High Rate Hydrogen Production
First published: 19 April 2022Electrocatalysts for high-rate hydrogen evolution reaction (HER) are crucial to clean fuel production. Nitrogen-rich 2D transition metal nitride, designated “nitridene”, has shown promising HER performance because of its unique physical/chemical properties. However, its synthesis is hindered by the sluggish growth kinetics. Here for the first time using a catalytic molten-salt method, we facilely synthesized a V−Mo bimetallic nitridene solid solution, V0.2Mo0.8N1.2, with tunable electrocatalytic property. The molten-salt synthesis reduces the growth barrier of V0.2Mo0.8N1.2 and facilitates V dissolution via a monomer assembly, as confirmed by synchrotron spectroscopy and ex situ electron microscopy. Furthermore, by merging computational simulations, we confirm that the V doping leads to an optimized electronic structure for fast protons coupling to produce hydrogen. These findings offer a quantitative engineering strategy for developing analogues of MXenes for clean energy conversions.Dr. Huanyu Jin, Dr. Huimin Yu, Dr. Haobo Li, Prof. Kenneth Davey, Dr. Taeseup Song, Prof. Ungyu Paik, Prof. Shi-Zhang Qia
Photoinduced 3D orientational order in side chain liquid crystalline azopolymers
We apply experimental technique based on the combination of methods dealing
with principal refractive indices and absorption coefficients to study the
photoinduced 3D orientational order in the films of liquid crystalline (LC)
azopolymers. The technique is used to identify 3D orientational configurations
of trans azobenzene chromophores and to characterize the degree of ordering in
terms of order parameters. We study two types of LC azopolymers which form
structures with preferred in-plane and out-of-plane alignment of
azochromophores, correspondingly. Using irradiation with the polarized light of
two different wavelengths we find that the kinetics of photoinduced anisotropy
can be dominated by either photo-reorientation or photoselection mechanisms
depending on the wavelength. We formulate the phenomenological model describing
the kinetics of photoinduced anisotropy in terms of the isomer concentrations
and the order parameter tensor. We present the numerical results for absorption
coefficients that are found to be in good agreement with the experimental data.
The model is also used to interpret the effect of changing the mechanism with
the wavelength of the pumping light.Comment: uses revtex4 28 pages, 10 figure
Final analysis of the international observational S-Collate study of peginterferon alfa-2a in patients with chronic hepatitis B
Background and aims Sustained off-treatment immune control is achievable in a proportion of patients with chronic hepatitis B treated with peginterferon alfa-2a. We evaluated on-treatment predictors of hepatitis B surface antigen (HBsAg) clearance 3 years after peginterferon alfa-2a treatment and determined the incidence of hepatocellular carcinoma. Methods A prospective, international, multicenter, observational study in patients with chronic hepatitis B who have been prescribed peginterferon alfa-2a (40KD) in a real-world setting. The primary endpoint was HBsAg clearance after 3 years' follow-up. Results The modified intention-to-treat population comprised 844 hepatitis B e antigen (HBeAg)positive patients (540 [64%] completed 3 years' follow-up), and 872 HBeAg-negative patients (614 [70%] completed 3 years' follow-up). At 3 years' follow-up, HBsAg clearance rates in HBeAg-positive and HBeAg-negative populations, respectively, were 2% (16/844) and 5% (41/872) in the modified intention-to-treat population and 5% [16/328] and 10% [41/ 394] in those with available data. In HBeAg-positive patients with data, Week 12 HBsAg levels <1500, 1500-20,000, and >20,000 IU/mL were associated with HBsAg clearance rates at 3 years' follow-up of 11%, 1%, and 5%, respectively (Week 24 predictability was similar). In HBeAg-negative patients with available data, a 6510% decline vs a <10% decline in HBsAg at Week 12 was associated with HBsAg clearance rates of 16% vs 4%. Hepatocellular carcinoma incidence was lower than REACH-B (Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B) model predictions. Conclusions Sustained off-treatment immune control is achieved with peginterferon alfa-2a in a real-world setting. HBsAg clearance 3 years after completion of peginterferon alfa-2a can be predicted on the basis of on-treatment HBsAg kinetics
Stabilizing entanglement autonomously between two superconducting qubits
Quantum error-correction codes would protect an arbitrary state of a
multi-qubit register against decoherence-induced errors, but their
implementation is an outstanding challenge for the development of large-scale
quantum computers. A first step is to stabilize a non-equilibrium state of a
simple quantum system such as a qubit or a cavity mode in the presence of
decoherence. Several groups have recently accomplished this goal using
measurement-based feedback schemes. A next step is to prepare and stabilize a
state of a composite system. Here we demonstrate the stabilization of an
entangled Bell state of a quantum register of two superconducting qubits for an
arbitrary time. Our result is achieved by an autonomous feedback scheme which
combines continuous drives along with a specifically engineered coupling
between the two-qubit register and a dissipative reservoir. Similar autonomous
feedback techniques have recently been used for qubit reset and the
stabilization of a single qubit state, as well as for creating and stabilizing
states of multipartite quantum systems. Unlike conventional, measurement-based
schemes, an autonomous approach counter-intuitively uses engineered dissipation
to fight decoherence, obviating the need for a complicated external feedback
loop to correct errors, simplifying implementation. Instead the feedback loop
is built into the Hamiltonian such that the steady state of the system in the
presence of drives and dissipation is a Bell state, an essential building-block
state for quantum information processing. Such autonomous schemes, broadly
applicable to a variety of physical systems as demonstrated by a concurrent
publication with trapped ion qubits, will be an essential tool for the
implementation of quantum-error correction.Comment: 39 pages, 7 figure
Decoherence in dc SQUID phase qubits
We report measurements of Rabi oscillations and spectroscopic coherence times
in an Al/AlOx/Al and three Nb/AlOx/Nb dc SQUID phase qubits. One junction of
the SQUID acts as a phase qubit and the other junction acts as a
current-controlled nonlinear isolating inductor, allowing us to change the
coupling to the current bias leads in situ by an order of magnitude. We found
that for the Al qubit a spectroscopic coherence time T2* varied from 3 to 7 ns
and the decay envelope of Rabi oscillations had a time constant T' = 25 ns on
average at 80 mK. The three Nb devices also showed T2* in the range of 4 to 6
ns, but T' was 9 to 15 ns, just about 1/2 the value we found in the Al device.
For all the devices, the time constants were roughly independent of the
isolation from the bias lines, implying that noise and dissipation from the
bias leads were not the principal sources of dephasing and inhomogeneous
broadening.Comment: 5 figures. Accepted to Physical Review
Immunohistochemical evaluation of human epidermal growth factor receptor 2 and estrogen and progesterone receptors in breast carcinoma in Jordan
INTRODUCTION: Although breast carcinoma (BC) is the most common malignancy affecting Jordanian females and the affected population in Jordan is younger than that in the West, no information is available on its biological characteristics. Our aims in this study are to evaluate the expression of estrogen receptor (ER) and progesterone receptor (PR) and Her-2/neu overexpression in BC in Jordan, and to compare the expression of these with other prognostic parameters for BC such as histological type, histological grade, tumor size, patients' age, and number of lymph node metastases. METHOD: This is a retrospective study conducted in the Department of Pathology at Jordan University of Science and Technology. A confirmed 91 cases of BC diagnosed in the period 1995 to 1998 were reviewed and graded. We used immunohistochemistry to evaluate the expression of ER, PR, and Her-2. Immunohistochemical findings were correlated with age, tumor size, grade and axillary lymph node status. RESULTS: Her-2 was overexpressed in 24% of the cases. The mean age of Her-2 positive cases was 42 years as opposed to 53 years among Her-2 negative cases (p = 0.0001). Her-2 expression was inversely related to ER and PR expression. Her-2 positive tumors tended to be larger than Her-2 negative tumors with 35% overexpression among T3 tumors as opposed to 22% among T2 tumors (p = 0.13). Her-2 positive cases tended to have higher rates of axillary metastases, but this did not reach statistical significance. ER and PR positive cases were seen in older patients with smaller tumor sizes. CONCLUSION: Her-2 overexpression was seen in 24% of BC affecting Jordanian females. Her-2 overexpression was associated with young age at presentation, larger tumor size, and was inversely related to ER and PR expression. One-fifth of the carcinomas were Her-2 positive and ER negative. This group appears to represent an aggressive form of BC presenting at a young age with large primary tumors and a high rate of four or more axillary lymph node metastases
The Interspersed Spin Boson Lattice Model
We describe a family of lattice models that support a new class of quantum
magnetism characterized by correlated spin and bosonic ordering [Phys. Rev.
Lett. 112, 180405 (2014)]. We explore the full phase diagram of the model using
Matrix-Product-State methods. Guided by these numerical results, we describe a
modified variational ansatz to improve our analytic description of the
groundstate at low boson frequencies. Additionally, we introduce an
experimental protocol capable of inferring the low-energy excitations of the
system by means of Fano scattering spectroscopy. Finally, we discuss the
implementation and characterization of this model with current circuit-QED
technology.Comment: Submitted to EPJ ST issue on "Novel Quantum Phases and Mesoscopic
Physics in Quantum Gases
- …