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performance theory

Xinlu Zhang, Su Zhang, Jinjer Huang, Kaibo Ni
We first investigate the polarization coexistence and switching between the orthogonal π- and σ-polarization states in a free running optical bistability Tm,Ho:LLF laser. The output performances of the optical bistability Tm,Ho:LLF laser is numerically simulated, based on a new rate equation theory model taking into account the influences of polarization-dependent gain and losses. The simulation results show the polarization coexistence and switching of output laser in the process of decreasing pump power...
July 9, 2018: Optics Express
Zhaoyuan Yu, Zhichao Jin, Meng Duan, Ruopeng Bai, Yixin Lu, Yu Lan
A combination of theoretical and experimental studies were performed to explore the mechanism, regioselectivity, and enantioselectivity of phosphine-catalyzed [3+2] annulation between allenoates and acrylate or imine. Using density functional theory computations, we predicted that the enantioselective determining step is the nucleophilic addition of acrylate or imine to the catalyst-activated allenoate. In the key step, we proposed two hydrogen bonding interaction models (intermolecular H-bond model and intramolecular H-bond model)...
August 16, 2018: Journal of Organic Chemistry
Lacey B Robinson, Carlos A Camargo
Acid suppressant medications, such as proton pump inhibitors and histamine-2 receptor antagonists, are used often and throughout the lifespan. These medications have been linked to the development of a variety of allergic diseases. Areas covered: This review discusses prior studies investigating the association between acid suppressant medication exposure and the development of allergic diseases. We performed a thorough literature search to identify potentially relevant studies for inclusion. In summary, exposure to these medications prenatally, in childhood and in adulthood may increase the risk of allergic diseases...
August 16, 2018: Expert Review of Clinical Immunology
Louise A Horrigan
Laboratory practical programs are expected to fulfill many roles in the learning process, including the development of laboratory skills and problem-solving skills. However, little is known about the role of laboratory practical classes in the conceptual learning of physiology. Therefore, the main aims of this study were to identify some of the threshold concepts in physiology and to explore the role of our laboratory practical program in helping students to tackle these concepts. An online questionnaire gathered opinions from students on the value of the laboratory classes in helping them to learn...
September 1, 2018: Advances in Physiology Education
A J C Varandas
The complete basis set (CBS) limit is secluded in calculations of electronic structure, and hence CBS extrapolation draws immediate attention. Of the highest importance is the extremely slow-convergent correlation energy as obtained both from Møller-Plesset perturbation theory (MP2) and the gold standard coupled cluster singles, doubles, and perturbative triples method [CCSD(T)], both picked as the focal point. Because today's massive electronic structure calculations demand schemes for CBS extrapolation from the lowest rungs of the hierarchical staircase, the focus is also on how minimal and subminimal basis sets can help in the endeavour...
August 16, 2018: Physical Chemistry Chemical Physics: PCCP
John M Neuhaus, Charles E McCulloch, Ross D Boylan
The timing and frequency of the measurement of longitudinal outcomes in databases may be associated with the value of the outcome. Such visit processes are termed outcome dependent, and previous work showed that conducting standard analyses that ignore outcome-dependent visit times can produce highly biased estimates of the associations of covariates with outcomes. The literature contains several classes of approaches to analyze longitudinal data subject to outcome-dependent visit times, and all of these are based on simplifying assumptions about the visit process...
August 15, 2018: Statistics in Medicine
Bahlol Rahimi, Hamed Nadri, Hadi Lotfnezhad Afshar, Toomas Timpka
BACKGROUND:  One common model utilized to understand clinical staff and patients' technology adoption is the technology acceptance model (TAM). OBJECTIVE:  This article reviews published research on TAM use in health information systems development and implementation with regard to application areas and model extensions after its initial introduction. METHOD:  An electronic literature search supplemented by citation searching was conducted on February 2017 of the Web of Science, PubMed, and Scopus databases, yielding a total of 492 references...
July 2018: Applied Clinical Informatics
Massimiliano Zanin, Juan Manuel Tuñas, Ernestina Menasalvas
Owing to the complexity of the human body, most diseases present a high interpersonal variability in the way they manifest, i.e. in their phenotype, which has important clinical repercussions-for instance, the difficulty in defining objective diagnostic rules. Here we explore the hypothesis that signs and symptoms used to define a disease should be understood in terms of the dispersion (as opposed to the average) of physical observables. To that end, we propose a computational framework, based on complex networks theory, to map groups of subjects to a network structure, based on their pairwise phenotypical similarity...
August 2018: Journal of the Royal Society, Interface
Xiao-Ming Ai, Li-Chen Ho, Lu-Lu Han, Jin-Jing Lu, Xiong Yue, Nian-Yin Yang
The extensive performance of splenectomy worldwide for patients suffered from splenic trauma has given rise to high risks of postoperative complications, which has been attracting increasing attention in recent years. Nowadays the spleen is regarded as a versatile organ of the human body, invested with various excellent properties. The spleen has been recognized to take a great part in lipid metabolism. While removal of the spleen intends to alter lipid values, especially with an elevated LDL, splenic autotransplantation is able to normalize these lipid alterations...
August 16, 2018: Lipids in Health and Disease
Thomas P Fay, Lachlan P Lindoy, David E Manolopoulos
Radical pair recombination reactions are normally described using a quantum mechanical master equation for the electronic and nuclear spin density operator. The electron spin state selective (singlet and triplet) recombination processes are described with a Haberkorn reaction term in this master equation. Here we consider a general spin state selective electron transfer reaction of a radical pair and use Nakajima-Zwanzig theory to derive the master equation for the spin density operator, thereby elucidating the relationship between non-adiabatic reaction rate theory and the Haberkorn reaction term...
August 14, 2018: Journal of Chemical Physics
Filip Formalik, Michael Fischer, Justyna Rogacka, Lucyna Firlej, Bogdan Kuchta
The adequate choice of the interaction model is essential to reproduce qualitatively and estimate quantitatively the experimentally observed characteristics of materials or phenomena in computer simulations. Here we present the results of a benchmarking of density-functional theory calculations of rigid and flexible metal-organic frameworks (MOFs). The stability of these systems depends on the dispersion interactions. We compare the performance of two functionals, Perdew-Burke-Ernzerhof (PBE) and PBE designed for solids, with and without the dispersion corrections (D2 and TS), in reproducing the high-accuracy low-temperature X-ray and neutron diffraction data for both groups of MOFs...
August 14, 2018: Journal of Chemical Physics
Yuchong Zhang, Arjun Valiya Parambathu, Walter G Chapman
Modified inhomogeneous statistical associating fluid theory (iSAFT) density functional theory is extended to dendrimer molecules in solvents of varying quality. The detailed structures of isolated dendrimers in implicit solvent are calculated and have a semi-quantitative agreement with simulation results available in the literature. The dendrimers form dense-core structures under all conditions, while their radius of gyration follows different scaling laws. Factors that affect the quality of the solvent are systematically studied in the explicit solvent case...
August 14, 2018: Journal of Chemical Physics
Alexander A Doinikov, Benjamin Dollet, Philippe Marmottant
The subject of the present theoretical study is the dynamics of a cavitation bubble in a spherical liquid-filled cavity surrounded by an infinite elastic solid. Two objectives are pursued. The first is to derive equations for the velocity and pressure fields throughout the liquid filling the cavity and equations for the stress and strain fields throughout the solid medium surrounding the cavity. This derivation is based on the results of our previous paper [A. A. Doinikov et al., Phys. Rev. E 97, 013108 (2018)10...
July 2018: Physical Review. E
Adelina Voukadinova, Mónika Valiskó, Dirk Gillespie
Classical density functional theory (DFT) is a useful tool to compute the structure of the electrical double layer because it includes ion-ion correlations due to excluded-volume effects (i.e., steric correlations) and ion screening effects (i.e., electrostatic correlations beyond the electrostatic mean-field potential). This paper systematically analyzes the accuracies of three different electrostatic excess free-energy functionals, as compared to Monte Carlo (MC) simulations of the planar electrical double layer, over a large parameter space...
July 2018: Physical Review. E
Chuan-Lei Yang, Xiang-Huan Zu, He-Chun Wang, Yin-Yan Wang
Aimed at the problem of exhaust gas recirculation (EGR) performance evaluation and optimal EGR rate determination of turbocharged diesel engines, an optimized decision-making method, based on grey theory and entropy weight, was proposed. The internal combustion pressure, fuel consumption rate, NOX , CO and smoke were selected as the decision-making targets and the initial decision-making model was established based on the traditional grey decision-making theory. According to the characteristics and optimization requirements of EGR, the optimal compromise between combustion and emission performance is proposed to transform into decision-making target weighting problem, then an optimized subjective weighting method based on expert scoring and grey relational analysis is proposed...
June 2018: Royal Society Open Science
Shengli Ding, Ruijie Li, Yufei Luo, Anhong Dang
In wireless optical communication systems, the coherent detection scheme suffers severe performance degradation due to the phase fluctuation and polarization offset. To deal with such challenges, we propose a polarization coherent optical communication scheme with adaptive polarization control (PCPC), where the transmitted continuous-wave light is split into two paths-the binary phase shift keying modulated signal light and the reference light-which are orthogonally polarized and combined before being sent to free space...
July 1, 2018: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Reza Ghafarian Shirazi, Frank Neese, Dimitrios A Pantazis
A test set of twelve aryl carbenes (AC12) is compiled with the purpose of establishing their adiabatic singlet-triplet energy splittings using correlated wave function based methods. The set covers both singlet and triplet ground state aryl carbenes, as well as a range of magnitudes for the ground state to excited state gap. The performance of coupled cluster methods is examined with respect to the reference wave function, the basis set, and a number of additional methodological parameters that enter the calculation...
August 15, 2018: Journal of Chemical Theory and Computation
Mònica Castellà-Creus, Pilar DELGado-Hito, Isabel Andrés-Martínez, Maria-Eulàlia Juvé-Udina
AIM: To understand the individualization process of the standardized care plan that nurses design for hospitalized patients. BACKGROUND: To apply the nursing process, it is advisable to use standardized care plans to standardize the diagnosis, planning and assessment stages. However, the fundamental element of this methodology is the individualization of the care plan. DESIGN: A qualitative study, framed within the constructivist paradigm and applying the Grounded Theory method, in accordance with Strauss and Corbin's approach...
August 14, 2018: Journal of Advanced Nursing
Bao Yang, Chenlong Yang, Yilin Sun, Jiang Du, Pinan Liu, Guijun Jia, Wang Jia, Yazhuo Zhang, Jisheng Wang, Yulun Xu, Shuo Wang
BACKGROUND: Mixed gangliocytoma-pituitary adenoma is an extremely rare tumor occurring in the sellar region, histologically composed of both gangliocytic and pituitary adenomatous architectures. The histogenesis of these tumors remains unknown, and the diagnosis, treatment, and prognosis are yet to be fully understood. METHODS: We retrospectively reviewed the clinical, radiological, and histopathological profiles from a series of 20 patients with sellar mixed gangliocytoma-pituitary adenomas...
August 14, 2018: Acta Neurochirurgica
Wenhan Zhou, Xuhai Liu, Xuemin Hu, Shengli Zhang, Chunyi Zhi, Bo Cai, Shiying Guo, Xiufeng Song, Zhi Li, Haibo Zeng
Identifying heterostructures with tunable band alignments remains a difficult challenge. Here, based on bond-orbital theory, we propose a series of new BN/BX (X = P, As, Sb) lateral heterostructures (LHS). Our first principles calculations reveal that the LHS interlines have a substantial impact on the electronic properties. Importantly, we start with the chemical concepts, such as bond length and strength as well as orbital overlap interaction, in an attempt to thoroughly investigate the electronic properties, namely the band offset, the band gap (Eg) and the state of the energy level...
August 15, 2018: Nanoscale
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