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Shenhe Fu, Jianying Zhou, Yongyao Li, Lev Shemer, Ady Arie
We report on the theoretical and experimental study of the generation of propagating waveguide modes on the water surface. These propagating modes are modulated in the transverse direction in a manner that satisfies boundary conditions on the walls of the water tank. It is shown that the propagating modes possess both anomalous and normal dispersion regimes, in contrast to the extensively studied zero mode that, in the case of deep water, only has normal dispersion with a fixed frequency independent dispersion coefficient...
April 7, 2017: Physical Review Letters
Wanzhuo Ma, Tianshu Wang, Yan Zhang, Peng Liu, Yuwei Su, Qingsong Jia, Mingzhe Bi, Peng Zhang, Huilin Jiang
We propose and experimentally demonstrate a widely tunable mode-locked thulium-doped fiber laser. The laser can operate at both continuous-wave and mode-locked states at different pump power levels. A classic nonlinear polarization rotation structure is employed to obtain the passive mode-locked laser. A birefringence Lyot filter as a fiber comb filter is used to expand the tuning range. Thanks to the filtering component, the tuning range of the continuous-wave laser can reach 127 nm (1823-1950 nm). The tuning ranges of the single-wavelength and dual-wavelength mode-locked lasers are 94 nm (1835-1929 nm) and 87 nm (1831-1918 nm), respectively, with a 3...
April 20, 2017: Applied Optics
Shuhei Hatanaka, Kazuhiko Sugiyama, Masatoshi Mitaki, Masatoshi Misono, Sergey N Slyusarev, Masao Kitano
We phase lock an octave-spanning optical frequency comb, generated using a mode-locked titanium-sapphire laser and a photonic-crystal fiber, to a continuous-wave laser line-narrowed to a reference cavity. To phase lock the pulse-repetition frequency, the cavity length of the mode-locked laser is controlled by using a fast piezoelectric-actuated mirror of a servo bandwidth up to 80 kHz. The residual phase noise is 0.35 rad, and 89% of the power is concentrated to the carrier. To apply the system to optical frequency-ratio measurements and to evaluate the phase locking, a simultaneous frequency measurement of the beat between the other mode of the comb and another laser line-narrowed to a different resonance of the common reference cavity is demonstrated...
April 20, 2017: Applied Optics
Seyed Mohsen Izadyar, Mohammad Razaghi, Abdollah Hassanzadeh
In this paper, a theoretical model for a quantum dot semiconductor optical amplifier (QDSOA) is proposed. The dynamics of carriers in ground, excited, and continuum states and wetting layer are considered in this model. The effects of the second excited state (ES2) inclusion are investigated for the first time, to the best of our knowledge, in the proposed QDSOA model. Moreover, the inhomogeneous broadening effect due to size distribution of dots, and the homogeneous broadening effect of a single dot in the gain spectrum by grouping of dots based on their optical resonant frequency, are included in the model...
April 20, 2017: Applied Optics
Mingming Nie, Qiang Liu, Encai Ji, Xuezhe Cao, Fu Xing, Mali Gong
In this paper, we demonstrated a hybrid master oscillator power amplifier (MOPA) laser with high peak power and widely tunable pulse repetition frequency (PRF) and pulse duration. The first-stage solid-state amplifier was carefully designed to keep good beam quality and supply high gain simultaneously. The maximum peak power of 760 kW was achieved with average power of 42 W, PRF of 50 kHz, pulse duration of 1.1 ns, and near-diffraction limited beam quality. The MOPA laser covers a broad tunable temporal range with 1-100 ns for pulse duration and 50 kHz-1 MHz for PRF...
April 20, 2017: Applied Optics
Chuan Guo, Junwei Zuo, Qi Bian, Chang Xu, Qinshuang Zong, Yong Bo, Yu Shen, Nan Zong, Hongwei Gao, Yanyong Lin, Lei Yuan, Yang Liu, Dafu Cui, Qinjun Peng, Zuyan Xu
We demonstrate a compact, high-power, quasi-continuous-wave (QCW) end-pumped 1319 nm Nd:YAG slab amplifier laser with good beam quality. The laser is based on a QCW pulse Nd:YAG master oscillator and Nd:YAG slab amplifier with multi-pass zigzag architecture. The amplifier operates at a pulse repetition frequency of 500 Hz and pulse width of ∼105  μs, delivering a maximum output power of 51.5 W under absorbed pump power of 217.8 W and corresponding to an extraction efficiency of 14.2%. The beam quality factor is measured to be Mx2=1...
April 20, 2017: Applied Optics
Harilaos G Sandalidis, Alexander Vavoulas, Theodoros A Tsiftsis, Nicholas Vaiopoulos
Visible light communication (VLC) is a promising technology that meets illumination and information transmission requirements in an indoor environment. Because light waves convey energy, a VLC link may exploit that fact for energy harvesting purposes. In this context, a single light emitting diode lamp located at a close distance over a tablet or laptop PC can potentially offer simultaneous lighting, Internet access, and battery recharging without cables. The present study introduces this threefold role of VLC systems by properly adapting some energy harvesting receiver architectures recently launched for usage in RF communications...
April 20, 2017: Applied Optics
Shota Moyama, Kazuhiro Minami, Mihiro Yano, Masumi Okumura, Susumu Hayashi, Hiroshi Takayama, Akira Yorimoto
BACKGROUND AND OBJECTIVES: Arterial stiffness is a leading cause of cardiovascular disease (CVD), and it is considered to be affected by dietary intake. However, few studies have examined the relationship between major dietary patterns and brachial-ankle pulse wave velocity (baPWV) among Japanese middle-aged subjects. We studied whether major dietary patterns were associated with baPWV in this population. METHODS AND STUDY DESIGN: Between 2009 and 2012, 70 Japanese middle-aged subjects (39 men and 31 women) with no history of stroke, coronary heart disease, or cancer were studied...
May 2017: Asia Pacific Journal of Clinical Nutrition
Raimundo Jenner, Fernanda Fatureto-Borges, Valéria Costa-Hong, Heno F Lopes, Sandra H Teixeira, Elias Marum, Dante A M Giorgi, Fernanda M Consolim-Colombo, Luiz A Bortolotto, Geraldo Lorenzi-Filho, Eduardo M Krieger, Luciano F Drager
Whether sex influences the association of obstructive sleep apnea (OSA) with markers of cardiovascular risk in patients with hypertension is unknown. In this study, 95 hypertensive participants underwent carotid-femoral pulse wave velocity, 24-hour ambulatory blood pressure monitoring, echocardiogram, and polysomnography after a 30-day standardized treatment with hydrochlorothiazide plus enalapril or losartan. OSA was present in 52 patients. Compared with non-OSA patients, pulse wave velocity values were higher in the OSA group (men: 11...
April 21, 2017: Journal of Clinical Hypertension
Çetin Geçmen, Gamze Babür Güler, Suzan Hatipoğlu, Muzaffer Kahyaoğlu, Murat Çap, Servet İzci, Çağatay Önal, Emrah Erdoğan, Aykun Hakgör, Özkan Candan, Arzu Kalaycı, Tuba Unkun, İbrahim Akın İzgi
OBJECTIVE: Bicuspid aortic valve (BAV) is a complex developmental anomaly caused by abnormal aortic leaflet formation during valvulogenesis. The present study is an assessment of the effects of BAV disease on the ascending aorta and pulmonary artery (PA), and an evaluation of the consequences for systolic and diastolic functioning of the left and right ventricles. METHODS: Total of 66 patients were eligible for inclusion. Pulmonary artery maximum diameter (PAD) was obtained 1 cm distal to the pulmonary annulus...
April 2017: Türk Kardiyoloji Derneği Arşivi: Türk Kardiyoloji Derneğinin Yayın Organıdır
John M Davis, Grace Lin, Jae K Oh, Cynthia S Crowson, Sara J Achenbach, Terry M Therneau, Eric L Matteson, Richard J Rodeheffer, Sherine E Gabriel
BACKGROUND: Patients with rheumatoid arthritis (RA) have increased risk of heart failure with preserved ejection fraction. The development and progression of left ventricular dysfunction before onset of clinical heart failure are unknown. The objective of this study was to evaluate longitudinal changes in cardiac structure and function of patients with RA compared with persons in the general population. METHODS: A prospective longitudinal study of a population-based cohort of 160 patients with RA and a population-based cohort of 1391 persons without RA (non-RA cohort) was performed...
March 31, 2017: International Journal of Cardiology
Danielle Di Cavalcanti, Lucas V Alves, Geraldo J Furtado, Cleusa C Santos, Fabiana G Feitosa, Maria C Ribeiro, Paulo Menge, Izabelle M Lira, Joao G Alves
OBJECTIVE: To report the echocardiographic evaluation of 103 infants with presumed congenital Zika syndrome. METHODS: An observational retrospective study was performed at Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Recife, Brazil. 103 infants with presumed congenital Zika syndrome. All infants had microcephaly and head computed tomography findings compatible with congenital Zika syndrome. Zika IgM antibody was detected in cerebrospinal fluid samples of 23 infants...
2017: PloS One
Yu Liu, Jingfei Liu, Brett Z Fite, Josquin Foiret, Asaf Ilovitsh, J Kent Leach, Erik Dumont, Charles F Caskey, Katherine W Ferrara
Non-invasive, quantitative methods to assess the properties of biological tissues are needed for many therapeutic and tissue engineering applications. Magnetic resonance elastography (MRE) has historically relied on external vibration to generate periodic shear waves. In order to focally assess a biomaterial or to monitor the response to ablative therapy, the interrogation of a specific region of interest by a focused beam is desirable and transient MRE (t-MRE) techniques have previously been developed to accomplish this goal...
April 20, 2017: Physics in Medicine and Biology
Hirobumi Mineo, Yuichi Fujimura
Control of π-electrons in polycyclic aromatic hydrocarbons (PAHs) is one of the fundamental issues in optoelectronics for ultrafast optical switching devices. We have proposed an effective scenario for design of the generation of coherent ring currents in naphthalene (D2h), which is the smallest unit of planar PAHs. It has been demonstrated by using quantum chemical calculations and quantum optimal control (QOC) simulations that two types of ring currents, parallel and antiparallel ones, can be generated by resonance excitations by two linearly polarized lasers...
April 20, 2017: Journal of Physical Chemistry Letters
Kevin Mader, Richard Nauber, Vladimir Galindo, Hannes Beyer, Lars Buttner, Sven Eckert, Jurgen Czarske
Controllable magnetic fields can be used to optimize flows in technical and industrial processes involving liquid metals in order to improve quality and yield. However, experimental studies in magnetohydrodynamics (MHD) often involve complex, turbulent flows and require planar, two-component velocity measurements through only one acoustical access. We present the phased array ultrasound Doppler velocimeter (PAUDV) as a modular research platform for flow mapping in liquid metals. It combines the pulse wave Doppler method with the phased array technique to adaptively focus the ultrasound beam...
April 12, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Chen Li, Chanjuan Li, Wei Zhang, Ling Wang, Zhidong Wang, Yongji Wang, Jielai Xia
BACKGROUND: An ideal arterial pressure monitoring system for perioperative care is required to be accurate, noninvasive, continuous, and risk free. Although several continuous noninvasive arterial pressures (CNAP) are determined on the finger, a new wrist CNAP monitoring system was developed. This prospective study was designed as a randomized-controlled trial to assess its validity in comparison with invasive arterial pressure (IAP) monitoring. PATIENTS AND METHODS: Sixty patients undergoing elective surgery under general anesthesia were enrolled...
April 17, 2017: Blood Pressure Monitoring
Luisa Helena Maia Leite, Ariel Cohen, Franck Boccara
People living with human immunodeficiency virus (HIV) infection and receiving antiretroviral therapy now have the same life expectancy as the general population. However, they have a higher risk of atherosclerotic cardiovascular events because of a complex and polyfactorial vasculopathy, combining the effects of antiretroviral therapy, the HIV virus itself, immune activation, chronic inflammation and metabolic disturbances. Whether people living with HIV infection experience increased vascular aging compared with the general population remains controversial...
April 14, 2017: Archives of Cardiovascular Diseases
Chia-Hui Chang, Ya-Hui Hu, Yao-Chou Tsai, Che-Hsiung Wu, Shuo-Meng Wang, Lian-Yu Lin, Yen-Hung Lin, Fumitoshi Satoh, Kwan-Dun Wu, Vin-Cent Wu
The aim of this study was to show the effect of KCNJ5 mutational status on arterial stiffness in aldosterone-producing adenomas after adrenalectomy. Between February 2008 and January 2010, we prospectively enrolled 108 aldosterone-producing adenoma patients undergoing adrenalectomy. We conducted repeated measurements of pulse wave velocity at baseline, 6 months, and 12 months after adrenalectomy, grouped by KCNJ5 mutational status. Prognostic factors of arterial stiffness and risk for hypertension at 12 months after adrenalectomy were analyzed after propensity score matching in a 1:1 ratio...
March 16, 2017: Oncotarget
Mohammad Hasanzadeh, Fozieh Mokhtari, Nasrin Shadjou, Aziz Eftekhari, Ahad Mokhtarzadeh, Vahid Jouyban-Gharamaleki, Soltanali Mahboob
This study reports on the electropolymerization of a low toxic and biocompatible polymer with entitle poly arginine-graphene quantum dots (PARG-GQDs) as a novel strategy for surface modification of glassy carbon (GC) surface and preparation a new interface for biomedical application. The fabrication of PARG-GQDs on GCE was performed using Layer-by-layer regime. Scanning electron microscopy (SEM) was confirmed dispersion of GQDs on the surface of PARG which lead to increase of surface coverage of PARG. The redox behavior of prepared sensor was then characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CHA), square wave voltammetry (SWV), linear sweep voltammetry (LSV)...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
M S Krivokorytov, A Yu Vinokhodov, Yu V Sidelnikov, V M Krivtsun, V O Kompanets, A A Lash, K N Koshelev, V V Medvedev
The deformation and fragmentation of liquid metal microdroplets by intense subpicosecond Ti:sapphire laser pulses is experimentally studied with stroboscopic shadow photography. The experiments are performed at a peak intensity of 10^{14}W/cm^{2} at the target's surface, which produces shock waves with pressures in the Mbar range. As a result of such a strong impact, the droplet is transformed into a complex-shaped hollow structure that undergoes asymmetrical expansion and eventually fragments. The hollow structure of the expanding target is explained by the effects of cavitation and spallation that follow the propagation of the laser-induced shock wave...
March 2017: Physical Review. E
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