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Amal Abdelhamid, Meriem Jouini, Haifa Bel Haj Amor, Zeineb Mzoughi, Mehdi Dridi, Rafik Ben Said, Abderrahman Bouraoui
Phlorotannins, phenolic compounds produced exclusively by seaweeds, have been reported to possess various pharmacological properties. However, there have been few works on these compounds from Mediterranean seaweeds. In this study, we investigated the phytochemical analysis and pharmacological potential of phlorotannin-rich fractions from three brown seaweeds collected along the Tunisia coast: Cystoseira sedoides (PHT-SED), Cladostephus spongeosis (PHT-CLAD), and Padina pavonica (PHT-PAD). Phytochemical determinations showed considerable differences in total phenolic content (TPC) and phlorotannin content (PHT)...
January 18, 2018: Marine Biotechnology
Li Jiahong, Kong Dejun
Cr-Ni coatings with the mass ratios of 17% Cr-83% Ni, 20% Cr-80% Ni and 24% Cr-76% Ni were fabricated on H13 hot work mould steel using a laser cladding (LC). The surface-interface morphologies, chemical elements, surface roughness and phase composition of the obtained Cr-Ni coatings were analysed using a scanning electron microscope (SEM), energy disperse spectroscopy (EDS), atomic force microscope (AFM) and X-ray diffractometer (XRD), respectively. The friction-wear properties and wear rates of Cr-Ni coatings with the different mass ratios of Cr and Ni at 600 °C were investigated, and the worn morphologies and wear mechanism of Cr-Ni coatings were analysed...
January 15, 2018: Materials
Christopher E Sunday, Dmitry Veksler, Kin C Cheung, Yaw S Obeng
Traditional metrology has been unable to adequately address the needs of the emerging integrated circuits (ICs) at the nano scale; thus, new metrology and techniques are needed. For example, the reliability challenges in fabrication need to be well understood and controlled to facilitate mass production of through-substrate-via (TSV) enabled three-dimensional integrated circuits (3D-ICs). This requires new approaches to the metrology. In this paper, we use the microwave propagation characteristics to study the reliability issues that precede the physical damage caused by electromigration in the Cu-filled TSVs...
November 7, 2017: Journal of Applied Physics
Viphretuo Mere, Rakshitha Kallega, Shankar Kumar Selvaraja
We present a novel photonic wire-to-slot waveguide coupler in SOI. The phase matching between a wire and slot mode is achieved using a mode transformer. The architecture consists of a balanced 50/50 power splitter and a tunable phase matched taper combiner forming a slot waveguide. We show a theoretical wire-to-slot coupling efficiency of 99 % is achievable and experimentally, we demonstrate a coupling efficiency of 99 % in the 1550 nm band. Based on the coupling scheme, we also show excitation of a slot mode in a slotted ring resonator and verified the excitation through the thermo-optic response of the rings...
January 8, 2018: Optics Express
S Wolf, H Zwickel, C Kieninger, M Lauermann, W Hartmann, Y Kutuvantavida, W Freude, S Randel, C Koos
We demonstrate the generation of higher-order modulation formats using silicon-based inphase/quadrature (IQ) modulators at symbol rates of up to 100 GBd. Our devices exploit the advantages of silicon-organic hybrid (SOH) integration, which combines silicon-on-insulator waveguides with highly efficient organic electro-optic (EO) cladding materials to enable small drive voltages and sub-millimeter device lengths. In our experiments, we use an SOH IQ modulator with a π-voltage of 1.6 V to generate 100 GBd 16QAM signals...
January 8, 2018: Optics Express
Changyu Shen, Chuan Zhong, Dejun Liu, Xiaokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, John F Donegan
Small lateral forces (lower than 0.1 N) cannot normally be measured with conventional single-mode fiber-based sensors because of the high value of their Young modulus (>70  GPa). Here we demonstrate the measurement of lateral forces in the range from 0.2 to 1.4×10-3  N with a tilted fiber Bragg grating (TFBG) in conventional single-mode fiber pushed against the surface tension (ST) of a bead of water. The measured transmission changes of individual cladding mode resonances of the TFBG corresponding to these force values are of the order of 29 dB...
January 15, 2018: Optics Letters
Harald Ian Muri, Andon Bano, Dag Roar Hjelme
We report on characterization of an optical fiber-based multi-parameter sensor concept combining localized surface plasmon resonance (LSPR) signal and interferometric sensing using a double-clad optical fiber. The sensor consists of a micro-Fabry-Perot in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanorods on the facet of a cleaved double-clad optical fiber. The swelling degree of the hydrogel is measured interferometrically using the single-mode inner core, while the LSPR signal is measured using the multi-mode inner cladding...
January 11, 2018: Sensors
Mark Benzimra, Greg L Calligaro, Allan R Glanville
Despite induction immunosuppression and the use of aggressive maintenance immunosuppressive regimens, acute allograft rejection following lung transplantation is still a problem with important diagnostic and therapeutic challenges. As well as causing early graft loss and mortality, acute rejection also initiates the chronic alloimmune responses and airway-centred inflammation that predispose to bronchiolitis obliterans syndrome (BOS), also known as chronic lung allograft dysfunction (CLAD), which is a major source of morbidity and mortality after lung transplantation...
December 2017: Journal of Thoracic Disease
Zhengyong Liu, Lin Htein, Kang-Kuen Lee, Kin-Tak Lau, Hwa-Yaw Tam
This paper presents a sensitive and large dynamic range pressure sensor based on a novel birefringence microstructured optical fiber (MOF) deployed in a Sagnac interferometer configuration. The MOF has two large semicircle holes in the cladding and a rectangular strut with germanium-doped core in the center. The fiber structure permits surrounding pressure to induce large effective index difference between the two polarized modes. The calculated and measured group birefringence of the fiber are 1.49 × 10-4, 1...
January 8, 2018: Scientific Reports
Anand Mohan Shrivastav, Banshi D Gupta
We report the design, fabrication, and characterization of an optical fiber sensor based on the surface plasmon resonance (SPR) technique for the simultaneous determination of lead (Pb) and copper (Cu) metal ions in aqueous samples. Two cascade channels over a single optical fiber are fabricated by removing cladding from two well-separated regions of the fiber. SPR working as a transducing mechanism for the sensor is realized by coating thin films of copper and silver over unclad cores of channel I and channel II, respectively...
January 2018: Journal of Biomedical Optics
Tao Chen, Defu Liu, Fan Wu, Haojun Wang
To solve the lack of wear resistance of titanium alloys for use in biological applications, various prepared coatings on titanium alloys are often used as wear-resistant materials. In this paper, TiC bioinert coatings were fabricated on Ti6Al4V by laser cladding using mixed TiC and ZrO₂ powders as the basic pre-placed materials. A certain amount of CeO₂ powder was also added to the pre-placed powders to further improve the properties of the TiC coatings. The effects of CeO₂ additive on the phase constituents, microstructures and wear resistance of the TiC coatings were researched in detail...
December 31, 2017: Materials
Yoshito Yamada, Tim Langner, Ilhan Inci, Christian Benden, Macé Schuurmans, Walter Weder, Wolfgang Jungraithmayr
OBJECTIVES: Human leucocyte antigen (HLA) mismatch between donor and recipient has a differential impact on the outcome after transplant (Tx) among transplantable solid organs. Although the lung is considered a highly antigenic organ, the impact of HLA matching between the donor and the recipient has been shown to be heterogeneous on lung Tx outcome. To provide further evidence that HLA matching should be considered in the decision process prior to lung Tx, we evaluated the impact of donor/recipient HLA mismatch on the outcome after lung Tx at our institution...
January 2, 2018: Interactive Cardiovascular and Thoracic Surgery
Mei Ma, Shouwu Guo, Wenzhuo Shen
Tetravalent metal phosphates (M(HPO4)2, M=Zr, Sn, and Ti) have robust layered structure with the interlayer d-spacing over 7.5 Å, but show poor electric conductivity. On the other hand, single-atomic-layered reduced graphene oxide (rGO) sheets exhibit a high electric conductivity. In this work, the combination of rGO and M(HPO4)2 is explored for their potential as anode materials for lithium ion batteries (LIBs). Specifically, rGO/M(HPO4)2 composites are prepared, and their electrochemical performances are investigated systematically...
January 3, 2018: ACS Applied Materials & Interfaces
Liuyang Fang, Hua Yan, Yansong Yao, Peilei Zhang, Qiushi Gao, Yang Qin
The CrS/NbC Co-based self-lubricating composite coatings were successfully fabricated on Cr12MoV steel surface by laser clad Stellite 6, WS₂, and NbC mixed powders. The phase composition, microstructure, and tribological properties of the coatings ware investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS), as well as dry sliding wear testing. Based on the experimental results, it was found reactions between WS₂ and Co-based alloy powder had occurred, which generated solid-lubricant phase CrS, and NbC play a key role in improving CrS nuclear and refining microstructure of Co-based composite coating during laser cladding processing...
December 28, 2017: Materials
Paweł Kalinowski, Anna Krawulska
BACKGROUND Spinal pain affects approximately 45-56% of pregnant women. Kinesio taping (KT) involves application of flexible water-resistant elastic bands on the patient's body, resulting in painless and non-invasive stimulation. The aim of the study was to determine the influence of KT on reduction of low back pain in pregnant women. MATERIAL AND METHODS Kinesio Tex Gold tapes were applied using the muscular-ligament technique and Polovis Plus textile cladding blinded the sample. The starting position for the KT and placebo with lumbar spine flexion with rotation was in the opposite direction to the application...
December 26, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Satoshi Kimura, Toshiyasu Ogata, Junko Watanabe, Tooru Inoue, Yoshio Tsuboi
Purpose: Although many patients with cerebral large-artery disease (CLAD) show impaired cognitive performance, the risk factors remain unclear in this population. The objective of this study was to evaluate cognitive impairment and its risk factors in patients with CLAD. Methods: We recruited non-demented patients with CLAD from our hospital. CLAD was defined as occlusion or stenosis of over 50% in the carotid artery or middle cerebral artery. We collected patients' biographical data and vascular lesion and imaging data, including periventricular hyperintensity (PVH) and cerebral perfusion...
September 2017: ENeurologicalSci
Oleg V Ivanov, Fan Yang, Fei Tian, Henry Du
We investigate thin-core fiber-optic structures with film overlays that can be used for sensing applications. The structures are formed by a section of thin-core fibers (SM630 or SM450) spliced between standard SMF-28 fibers. The fibers are coated with overlays using the layer-by-layer assembly technology based on sequential alternating adsorption of polymer monolayers via electrostatic attraction. Transmission spectrum of the structures exhibits resonance dips caused by interaction between cladding modes. We measure the shifts of spectra with increasing thickness of the overlay and with pH value of the external medium...
December 11, 2017: Optics Express
Edgars Nitiss, Andrejs Tokmakovs, Kaspars Pudzs, Janis Busenbergs, Martins Rutkis
In this paper we describe the principles of operation as well as the fabrication and testing steps of an all-organic waveguide modulator. The modulator comprises an SU-8 core and an electro-optic host-guest polymer cladding. The polymer properties are tuned in order to achieve single mode operation. We used direct-write laser lithography in two steps for the preparation of the devices. The electro-optic coefficient of the polymer is estimated from observing the modulation of the device operated in push-pull mode...
December 11, 2017: Optics Express
Hung-Ying Chang, Yu-Chung Chang, Wen-Fung Liu
We present a novel two-dimensional fiber-optic inclinometer with high sensitivity by crisscrossing two etched chirped fiber Bragg gratings (CFBG) arrays. Each array is composed of two symmetrically-arranged CFBGs. By etching away most of the claddings of the CFBGs to expose the evanescent wave, the reflection spectra are highly sensitive to the surrounding index change. When we immerse only part of the CFBG in liquid, the effective index difference induces a superposition peak in the refection spectrum. By interrogating the peak wavelengths of the CFBGs, we can deduce the tilt angle and direction simultaneously...
December 15, 2017: Sensors
Marie-Alicia Malleville, Romain Dauliat, Aurélien Benoît, Baptiste Leconte, Dia Darwich, Rémi du Jeu, Raphaël Jamier, Kay Schuster, Philippe Roy
We report here on an experimental investigation of the temporal behavior of transverse mode instabilities into "fully aperiodic large-pitch fibers" (FA-LPFs) operated in high-power continuous-wave laser configuration. To ensure an effective transverse single-mode emission into FA-LPFs, a perfect index matching between the active core and the background cladding materials (Δn=0) is required. The original design of such fibers enables an effective transverse single-mode emission by strengthening the higher-order mode delocalization out of the gain region, even for high heat load levels, consequently leading to the improvement of the beam spatial quality...
December 15, 2017: Optics Letters
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