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https://www.readbyqxmd.com/read/29786443/an-experimental-study-of-the-structural-effect-on-the-nanosecond-nonlinear-optical-response-of-o-doped-polycyclic-aromatic-hydrocarbons-pahs
#1
Ioannis Papadakis, Zoi Bouza, Aristeidis Stathis, Ioannis Orfanos, Stelios Couris, Tanja Miletić, Davide Bonifazi
The nonlinear optical response of some O-doped PAHs is systematically investigated in the present work aiming to understand the influence of structural effects on their nonlinear optical response. In that view, the third-order nonlinear optical properties of these PAHs were measured under 4 ns, visible (532 nm) and infrared (1064 nm) laser excitation. The O-doped PAHs were found exhibiting large saturable absorption and negative sign nonlinear refraction under visible excitation, both increasing with the addition of naphtalene units and with the number of O-atoms...
May 22, 2018: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/29785961/trajectories-of-childhood-blood-pressure-and-adult-left-ventricular-hypertrophy-the-bogalusa-heart-study
#2
Tao Zhang, Shengxu Li, Lydia Bazzano, Jiang He, Paul Whelton, Wei Chen
This longitudinal study aims to characterize longitudinal blood pressure (BP) trajectories from childhood and examine the impact of level-independent childhood BP trajectories on adult left ventricular hypertrophy (LVH) and remodeling patterns. The longitudinal cohort consisted of 1154 adults (787 whites and 367 blacks) who had repeated measurements of BP 4 to 15 times from childhood (4-19 years) to adulthood (20-51 years) and assessment of echocardiographic LV dimensions in adulthood. Model-estimated levels and linear slopes of BP at childhood age points were calculated in 1-year intervals using the growth curve parameters and their first derivatives, respectively...
May 21, 2018: Hypertension
https://www.readbyqxmd.com/read/29785958/association-between-hypertensive-disorders-in-pregnancy-and-particulate-matter-in-the-contiguous-united-states-1999-2004
#3
Tao Xue, Tong Zhu, Weiwei Lin, Evelyn O Talbott
Hypertensive disorders in pregnancy harm both maternal and infant health and have been linked to ambient particulate matter. However, existing studies are restricted to a local scale and remain inconsistent. A large-scale study is required to enrich the epidemiological evidence and explore the potential sources of the inconsistency. Making use of US birth certificates (1999-2004), and monitoring data from the environmental protection agency air quality networks, we associated hypertensive disorders in pregnancy with maternal exposure to fine particles or coarse particles using logistic regression analysis after adjusting for many covariates among >5 million subjects in the contiguous United States...
May 21, 2018: Hypertension
https://www.readbyqxmd.com/read/29785936/an-objective-parameter-to-classify-voice-signals-based-on-variation-in-energy-distribution
#4
Boquan Liu, Evan Polce, Jack Jiang
OBJECTIVES: The purpose of this paper is to introduce an iterative nonlinear weighted method based on the variation in spectral energy distribution present in a voice signal to differentiate between four voice types: type 1 voice signals are nearly periodic, type 2 voice signals have strong modulations and subharmonics, type 3 signals are chaotic, and type 4 signals are dominated by stochastic noise. STUDY DESIGN: A total of 135 voice signal samples of the sustained vowel /a/ were obtained from the Disordered Voice Database and then individually categorized into the appropriate voice types based on the classification system described in Sprecher et al (2010)...
May 18, 2018: Journal of Voice: Official Journal of the Voice Foundation
https://www.readbyqxmd.com/read/29785609/evaluation-of-focei-and-saem-estimation-methods-in-population-pharmacokinetic-analysis-using-nonmem-%C3%A2-across-rich-medium-and-sparse-sampling-data
#5
Waroonrat Sukarnjanaset, Thitima Wattanavijitkul, Sutep Jarurattanasirikul
BACKGROUND AND OBJECTIVES: First-order conditional estimation with interaction (FOCEI) is one of the most commonly used estimation methods in nonlinear mixed effects modeling, while the stochastic approximation expectation maximization (SAEM) is the newer estimation algorithm. This work aimed to compare the performance of FOCEI and SAEM methods when using NONMEM® with the classical one- and two-compartment models across rich, medium, and sparse data. METHODS: One- and two-compartment models of the previous studies were used to simulate data in three scenarios: rich, medium, and sparse data...
May 21, 2018: European Journal of Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/29785547/analysis-of-factors-affecting-outcomes-of-pregnancy-complicated-by-echinococcus-an-algorithm-for-approach-and-management
#6
Sebahattin Celik, Ozan Okyay, Erbil Karaman, Özlem Z Sert, Numan Cim, Tuba Y Okyay
PURPOSE: The management of hydatid disease (HD) co-occurring with pregnancy remains a challenge for physicians. We aimed to determine factors that were related to fetal and maternal outcomes in HD complicated pregnancies and then develop an approach/treatment algorithm. METHOD: All patients at the participating hospitals were first analyzed to determine whether they had HD. Only patients diagnosed with HD during the course of their pregnancy were included. Certain cyst-related factors (diameter, localization, increase in size, and viability) and certain pregnancy-related factors (treatments, gestational week, maternal co-morbidities, and delivery type) were investigated...
May 21, 2018: Archives of Gynecology and Obstetrics
https://www.readbyqxmd.com/read/29785337/modelling-the-growth-of-the-brown-frog-rana-dybowskii
#7
Qing Tong, Xiao-Peng Du, Zong-Fu Hu, Li-Yong Cui, Hong-Bin Wang
Well-controlled development leads to uniform body size and a better growth rate; therefore, the ability to determine the growth rate of frogs and their period of sexual maturity is essential for producing healthy, high-quality descendant frogs. To establish a working model that can best predict the growth performance of frogs, the present study examined the growth of one-year-old and two-year-old brown frogs ( Rana dybowskii ) from metamorphosis to hibernation (18 weeks) and out-hibernation to hibernation (20 weeks) under the same environmental conditions...
2018: PeerJ
https://www.readbyqxmd.com/read/29784998/polarization-insensitive-frequency-conversion-for-an-atom-photon-entanglement-distribution-via-a-telecom-network
#8
Rikizo Ikuta, Toshiki Kobayashi, Tetsuo Kawakami, Shigehito Miki, Masahiro Yabuno, Taro Yamashita, Hirotaka Terai, Masato Koashi, Tetsuya Mukai, Takashi Yamamoto, Nobuyuki Imoto
Long-lifetime quantum storages accessible to the telecom photonic infrastructure are essential to long-distance quantum communication. Atomic quantum storages have achieved subsecond storage time corresponding to 1000 km transmission time for a telecom photon through a quantum repeater algorithm. However, the telecom photon cannot be directly interfaced to typical atomic storages. Solid-state quantum frequency conversions fill this wavelength gap. Here we report on the experimental demonstration of a polarization-insensitive solid-state quantum frequency conversion to a telecom photon from a short-wavelength photon entangled with an atomic ensemble...
May 21, 2018: Nature Communications
https://www.readbyqxmd.com/read/29784968/ultranarrow-bandwidth-filter-based-on-a-thermal-eit-medium
#9
Gang Wang, Yu-Sheng Wang, Emily Kay Huang, Weilun Hung, Kai-Lin Chao, Ping-Yeh Wu, Yi-Hsin Chen, Ite A Yu
We present high-contrast electromagnetically-induced-transparency (EIT) spectra in a heated vapor cell of single isotope 87 Rb atoms. The EIT spectrum has both high resonant transmission up to 67% and narrow linewidth of 1.1 MHz. We get rid of the possible amplification resulted from the effects of amplification without population inversion and four-wave mixing. Therefore, this high transmitted light is not artificial. The theoretical prediction of the probe transmission agrees well with the data and the experimental parameters can be derived reasonably from the model...
May 21, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29784965/broadband-electrically-tunable-third-harmonic-generation-in-graphene
#10
Giancarlo Soavi, Gang Wang, Habib Rostami, David G Purdie, Domenico De Fazio, Teng Ma, Birong Luo, Junjia Wang, Anna K Ott, Duhee Yoon, Sean A Bourelle, Jakob E Muench, Ilya Goykhman, Stefano Dal Conte, Michele Celebrano, Andrea Tomadin, Marco Polini, Giulio Cerullo, Andrea C Ferrari
Optical harmonic generation occurs when high intensity light (>1010  W m- 2 ) interacts with a nonlinear material. Electrical control of the nonlinear optical response enables applications such as gate-tunable switches and frequency converters. Graphene displays exceptionally strong light-matter interaction and electrically and broadband tunable third-order nonlinear susceptibility. Here, we show that the third-harmonic generation efficiency in graphene can be increased by almost two orders of magnitude by controlling the Fermi energy and the incident photon energy...
May 21, 2018: Nature Nanotechnology
https://www.readbyqxmd.com/read/29784428/abrupt-change-in-ecological-systems-inference-and-diagnosis
#11
REVIEW
Zak Ratajczak, Stephen R Carpenter, Anthony R Ives, Christopher J Kucharik, Tanjona Ramiadantsoa, M Allison Stegner, John W Williams, Jien Zhang, Monica G Turner
Abrupt ecological changes are, by definition, those that occur over short periods of time relative to typical rates of change for a given ecosystem. The potential for such changes is growing due to anthropogenic pressures, which challenges the resilience of societies and ecosystems. Abrupt ecological changes are difficult to diagnose because they can arise from a variety of circumstances, including rapid changes in external drivers (e.g., climate, or resource extraction), nonlinear responses to gradual changes in drivers, and interactions among multiple drivers and disturbances...
May 18, 2018: Trends in Ecology & Evolution
https://www.readbyqxmd.com/read/29782679/mos-2-negative-capacitance-field-effect-transistors-with-subthreshold-swing-below-the-physics-limit
#12
Xingqiang Liu, Renrong Liang, Guoyun Gao, Caofeng Pan, Chunsheng Jiang, Qian Xu, Jun Luo, Xuming Zou, Zhenyu Yang, Lei Liao, Zhong Lin Wang
The Boltzmann distribution of electrons induced fundamental barrier prevents subthreshold swing (SS) from less than 60 mV dec-1 at room temperature, leading to high energy consumption of MOSFETs. Herein, it is demonstrated that an aggressive introduction of the negative capacitance (NC) effect of ferroelectrics can decisively break the fundamental limit governed by the "Boltzmann tyranny". Such MoS2 negative-capacitance field-effect transistors (NC-FETs) with self-aligned top-gated geometry demonstrated here pull down the SS value to 42...
May 21, 2018: Advanced Materials
https://www.readbyqxmd.com/read/29782534/linear-and-nonlinear-causal-relationship-between-energy-consumption-and-economic-growth-in-china-new-evidence-based-on-wavelet-analysis
#13
Junsheng Ha, Pei-Pei Tan, Kim-Leng Goh
The energy-growth nexus has important policy implications for economic development. The results from many past studies that investigated the causality direction of this nexus can lead to misleading policy guidance. Using data on China from 1953 to 2013, this study shows that an application of causality test on the time series of energy consumption and national output has masked a lot of information. The Toda-Yamamoto test with bootstrapped critical values and the newly proposed non-linear causality test reveal no causal relationship...
2018: PloS One
https://www.readbyqxmd.com/read/29782500/the-human-snail-transmission-environment-shapes-long-term-schistosomiasis-control-outcomes-implications-for-improving-the-accuracy-of-predictive-modeling
#14
David Gurarie, Nathan C Lo, Martial L Ndeffo-Mbah, David P Durham, Charles H King
INTRODUCTION: Schistosomiasis is a chronic parasitic trematode disease that affects over 240 million people worldwide. The Schistosoma lifecycle is complex, involving transmission via specific intermediate-host freshwater snails. Predictive mathematical models of Schistosoma transmission have often chosen to simplify or ignore the details of environmental human-snail interaction in their analyses. Schistosome transmission models now aim to provide better precision for policy planning of elimination of transmission...
May 21, 2018: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/29782415/measuring-transcutaneous-oxygenation-to-validate-the-duration-required-to-achieve-electrode-equilibration
#15
Nathaniel Chiang, Jitendra K Jain, Jamie Sleigh, Thodur Vasudevan
OBJECTIVE: The transcutaneous oxygenation measurement (TCOM) system is useful in assessing tissue viability. There are no clear recommendations regarding the duration required for the electrode to equilibrate and reliably evaluate tissue oxygenation values. The objective of this study was to validate the duration required to achieve electrode equilibration in a clinical setting. METHODS: Minute-by-minute recordings using TCOM (TCOM3; Radiometer Medical ApS, Brønshøj, Copenhagen) were obtained for 82 limbs in 50 participants...
June 2018: Advances in Skin & Wound Care
https://www.readbyqxmd.com/read/29781613/rational-design-of-the-first-lead-tin-fluorooxoborates-mb2o3f2-m-pb-sn-containing-flexible-two-dimensional-b6o12f6-%C3%A2-single-layers-with-widely-divergent-second-harmonic-generation-effects
#16
Min Luo, Fei Liang, Yunxia Song, Dan Zhao, Ning Ye, Zheshuai Lin
Molecular engineering design is a productive strategy on atomic-scale to optimize crystal structure and develop new-functional materials. Herein, the first lead/tin fluorooxoborates, MB2O3F2 (M=Pb, Sn), were rationally designed by employing the nonlinear optical crystal Sr2Be2B2O7 (SBBO) as a parent model. Compared with the rigid [Be6B6O15]∞ double layers in SBBO, MB2O3F2 have flexible two-dimensional [B6O12F6]∞ single layer, which not only keeps the NLO-favorable layered structure but also overcomes the structural instability issues of SBBO...
May 21, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29781478/perfect-balance-harmony-in-ba-2-no-3-oh-3-a-beryllium-free-nitrate-as-a-uv-nonlinear-optical-material
#17
Xuehua Dong, Ling Huang, Qingyu Liu, Hongmei Zeng, Zhien Lin, Dingguo Xu, Guohong Zou
A promising UV nonlinear optical material, beryllium-free nitrate Ba2NO3(OH)3, has been synthesized via modified high-temperature solid state reactions in a self-made high-pressure apparatus which exhibits a perfect balance of a large second harmonic generation coefficient, an appropriate birefringence for phase matching, a short UV absorption cutoff edge and physicochemical stabilities.
May 21, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29781174/derivative-estimation-for-longitudinal-data-analysis-examining-features-of-blood-pressure-measured-repeatedly-during-pregnancy
#18
Andrew J Simpkin, Maria Durban, Debbie A Lawlor, Corrie MacDonald-Wallis, Margaret T May, Chris Metcalfe, Kate Tilling
Estimating velocity and acceleration trajectories allows novel inferences in the field of longitudinal data analysis, such as estimating change regions rather than change points, and testing group effects on nonlinear change in an outcome (ie, a nonlinear interaction). In this article, we develop derivative estimation for 2 standard approaches-polynomial mixed models and spline mixed models. We compare their performance with an established method-principal component analysis through conditional expectation through a simulation study...
May 20, 2018: Statistics in Medicine
https://www.readbyqxmd.com/read/29780523/enantiopure-distorted-ribbon-shaped-nanographene-combining-two-photon-absorption-based-upconversion-and-circularly-polarized-luminescence
#19
Carlos M Cruz, Irene R Márquez, Inês F A Mariz, Victor Blanco, Carlos Sánchez-Sánchez, Jesús M Sobrado, José A Martín-Gago, Juan M Cuerva, Ermelinda Maçôas, Araceli G Campaña
Herein we describe a distorted ribbon-shaped nanographene exhibiting unprecedented combination of optical properties in graphene-related materials, namely upconversion based on two-photon absorption (TPA-UC) together with circularly polarized luminescence (CPL). The compound is a graphene molecule of ca. 2 nm length and 1 nm width with edge defects that promote the distortion of the otherwise planar lattice. The edge defects are an aromatic saddle-shaped ketone unit and a [5]carbohelicene moiety. This system is shown to combine two-photon absorption and circularly polarized luminescence and a remarkably long emission lifetime of 21...
April 28, 2018: Chemical Science
https://www.readbyqxmd.com/read/29780431/mathematical-modelling-of-bacterial-meningitis-transmission-dynamics-with-control-measures
#20
Joshua Kiddy K Asamoah, Farai Nyabadza, Baba Seidu, Mehar Chand, Hemen Dutta
Vaccination and treatment are the most effective ways of controlling the transmission of most infectious diseases. While vaccination helps susceptible individuals to build either a long-term immunity or short-term immunity, treatment reduces the number of disease-induced deaths and the number of infectious individuals in a community/nation. In this paper, a nonlinear deterministic model with time-dependent controls has been proposed to describe the dynamics of bacterial meningitis in a population. The model is shown to exhibit a unique globally asymptotically stable disease-free equilibrium ℰ 0 , when the effective reproduction number ℛ VT ≤ 1, and a globally asymptotically stable endemic equilibrium ℰ 1 , when ℛ VT > 1; and it exhibits a transcritical bifurcation at ℛ VT = 1...
2018: Computational and Mathematical Methods in Medicine
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