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Márió Gyuris, László Hackler, Lajos I Nagy, Róbert Alföldi, Eszter Rédei, Annamária Marton, Tibor Vellai, Nóra Faragó, Béla Ózsvári, Anasztázia Hetényi, Gábor K Tóth, Péter Sipos, Iván Kanizsai, László G Puskás
A series of novel curcuminoids were synthesised for the first time via a Mannich-3CR/organocatalysed Claisen-Schmidt condensation sequence. Structure-activity relationship (SAR) studies were performed by applying viability assays and holographic microscopic imaging to these curcumin analogues for anti-proliferative activity against A549 and H1975 lung adenocarcinoma cells. The TNFα-induced NF-κB inhibition and autophagy induction effects correlated strongly with the cytotoxic potential of the analogues. Significant inhibition of tumour growth was observed when the most potent analogue 44 was added in liposomes at one-sixth of the maximally tolerated dose in the A549 xenograft model...
May 26, 2017: Archiv der Pharmazie
Marjan Zakerin, Antonin Novak, Masaya Toda, Yves Emery, Filipe Natalio, Hans-Jürgen Butt, Rüdiger Berger
In this paper, we apply a digital holographic microscope (DHM) in conjunction with stroboscopic acquisition synchronization. Here, the temperature-dependent decrease of the first resonance frequency (S₁(T)) and Young's elastic modulus (E₁(T)) of silicon micromechanical cantilever sensors (MCSs) are measured. To perform these measurements, the MCSs are uniformly heated from T₀ = 298 K to T = 450 K while being externally actuated with a piezo-actuator in a certain frequency range close to their first resonance frequencies...
May 23, 2017: Sensors
Marco Dal Maschio, Joseph C Donovan, Thomas O Helmbrecht, Herwig Baier
We introduce a flexible method for high-resolution interrogation of circuit function, which combines simultaneous 3D two-photon stimulation of multiple targeted neurons, volumetric functional imaging, and quantitative behavioral tracking. This integrated approach was applied to dissect how an ensemble of premotor neurons in the larval zebrafish brain drives a basic motor program, the bending of the tail. We developed an iterative photostimulation strategy to identify minimal subsets of channelrhodopsin (ChR2)-expressing neurons that are sufficient to initiate tail movements...
May 17, 2017: Neuron
Manon Bardyn, Benjamin Rappaz, Keyvan Jaferzadeh, David Crettaz, Jean-Daniel Tissot, Inkyu Moon, Gerardo Turcatti, Niels Lion, Michel Prudent
BACKGROUND: Red blood cells collected in citrate-phosphate-dextrose can be stored for up to 42 days at 4 °C in saline-adenine-glucose-mannitol additive solution. During this controlled, but nevertheless artificial, ex vivo ageing, red blood cells accumulate lesions that can be reversible or irreversible upon transfusion. The aim of the present study is to follow several parameters reflecting cell metabolism, antioxidant defences, morphology and membrane dynamics during storage. MATERIALS AND METHODS: Five erythrocyte concentrates were followed weekly during 71 days...
May 2017: Blood Transfusion, Trasfusione del Sangue
Zengji Yue, Gaolei Xue, Juan Liu, Yongtian Wang, Min Gu
Holography has extremely extensive applications in conventional optical instruments spanning optical microscopy and imaging, three-dimensional displays and metrology. To integrate holography with modern low-dimensional electronic devices, holograms need to be thinned to a nanometric scale. However, to keep a pronounced phase shift modulation, the thickness of holograms has been generally limited to the optical wavelength scale, which hinders their integration with ultrathin electronic devices. Here, we break this limit and achieve 60 nm holograms using a topological insulator material...
May 18, 2017: Nature Communications
Jun-He Han, Ruo-Ping Li, Jun-Hui Liu, Fu-Sheng Hai, Ming-Ju Huang
We present two-step phase-shifting differential-recording digital holographic microscopy (TPD-DH in microscopy) for phase imaging of microscopic transparent elements. Two CCDs are employed to record two interferograms at two different defocusing distances. The interferograms on the two CCD cameras are shifted for a phase retarder 0 and π via an all-optics phase shifting unit. A novel algorithm is proposed to reconstruct both amplitude and phase distributions of the object wave from the recorded interferograms...
May 16, 2017: Scientific Reports
Martin Šiler, Petr Jákl, Oto Brzobohatý, Artem Ryabov, Radim Filip, Pavel Zemánek
Recent technological progress in a precise control of optically trapped objects allows much broader ventures to unexplored territory of thermal motion in non-linear potentials. In this work, we exploit an experimental set-up of holographic optical tweezers to experimentally investigate Brownian motion of a micro-particle near the inflection point of the cubic optical potential. We present two complementary views on the non-linear Brownian motion. On an ensemble of stochastic trajectories, we simultaneously determine (i) the detailed short-time position statistics and (ii) the long-distance first-passage time statistics...
May 10, 2017: Scientific Reports
Stephanie C Malek, Ho-Seok Ee, Ritesh Agarwal
We demonstrate reconfigurable phase-only computer-generated metasurface holograms with up to three image planes operating in the visible regime fabricated with gold nanorods on a stretchable polydimethylsiloxane substrate. Stretching the substrate enlarges the hologram image and changes the location of the image plane. Upon stretching, these devices can switch the displayed holographic image between multiple distinct images. This work opens up the possibilities for stretchable metasurface holograms as flat devices for dynamically reconfigurable optical communication and display...
May 10, 2017: Nano Letters
Longqing Cong, Prakash Pitchappa, Chengkuo Lee, Ranjan Singh
Controlling the phase of local radiation by using exotic metasurfaces has enabled promising applications in a diversified set of electromagnetic wave manipulation such as anomalous wavefront deflection, flat lenses, and holograms. Here, we theoretically and experimentally demonstrate an active phase transition in a micro-electromechanical system-based metadevice where both the phase response and the dispersion of the metamaterial cavity are dynamically tailored. The phase transition is determined by the radiative and the absorptive losses in a metal-insulator-metal cavity that obeys the coupled-mode theory...
May 4, 2017: Advanced Materials
Mohesh Moothanchery, Viswanath Bavigadda, Manojit Pramanik, Vincent Toal, Izabela Naydenova
Photoinduced shrinkage occurring in photopolymer layers during holographic recording was determined by phase shifting electronic speckle pattern interferometry. Phase maps were calculated from the changes in intensity at each pixel due to the phase differences introduced between object and reference beams. Shrinkage was then obtained from the changes in phase as recording proceeded. The technique allows for whole field measurement of the dimensional changes in photopolymers during holographic recording.
May 1, 2017: Optics Express
Soundararajan Vijayarathna, Yeng Chen, Jagat R Kanwar, Sreenivasan Sasidharan
Over the years a number of microscopy methods have been developed to assess the changes in cells. Some non-invasive techniques such as holographic digital microscopy (HDM), which although does not destroy the cells, but helps to monitor the events that leads to initiation of apoptotic cell death. In this study, the apoptogenic property and the cytotoxic effect of P. longifolia leaf methanolic extract (PLME) against the human cervical carcinoma cells (HeLa) was studied using light microscope (LM), holographic digital microscopy (HDM), scanning electron microscope (SEM) and transmission electron microscope (TEM)...
April 29, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Jason W Stafford, Bradley D Duncan, David J Rabb
Simultaneous range compression and aperture synthesis is experimentally demonstrated with a stepped linear frequency modulated waveform and holographic aperture ladar. The resultant three-dimensional (3D) data has high resolution in the aperture synthesis dimension and is recorded using a conventional low bandwidth focal plane array. Individual cross-range field segments are coherently combined using data driven registration and phase correction methods allowing range compression to be performed without the benefit of a coherent waveform...
May 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Olivier Flasseur, Corinne Fournier, Nicolas Verrier, Loïc Denis, Frédéric Jolivet, Anthony Cazier, Thierry Lépine
Lensless color microscopy (also called in-line digital color holography) is a recent quantitative 3D imaging method used in several areas including biomedical imaging and microfluidics. By targeting cost-effective and compact designs, the wavelength of the low-end sources used is known only imprecisely, in particular because of their dependence on temperature and power supply voltage. This imprecision is the source of biases during the reconstruction step. An additional source of error is the crosstalk phenomenon, i...
May 1, 2017: Applied Optics
Cesar G Tavera R, Manuel H De la Torre-I, Jorge M Flores-M, Ma Del Socorro Hernandez M, Fernando Mendoza-Santoyo, Manuel de J Briones-R, Jorge Sanchez-P
A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones...
May 1, 2017: Applied Optics
Lihan Guo, Xinke Wang, Peng Han, Wenfeng Sun, Shengfei Feng, Jiasheng Ye, Yan Zhang
A terahertz (THz) digital holographic imaging system is utilized to investigate natural dehydration processes in three types of biological tissues, including cattle, mutton, and pork. An image reconstruction algorithm is applied to remove the diffraction influence of THz waves and further improve clarity of THz images. From THz images of different biological specimens, distinctive water content as well as dehydration features of adipose and muscle tissues are precisely distinguished. By analyzing THz absorption spectra of these samples, temporal evolution characteristics of the absorbances for adipose and muscle tissues are described and compared in detail...
May 1, 2017: Applied Optics
Soumaya Kara Mohammed, Larbi Bouamama, Derradji Bahloul, Pascal Picart
This paper proposes a quality assessment of focusing criteria for imaging in digital off-axis holography. In the literature, several refocus criteria have been proposed in the past to get the best refocus distance in digital holography. As a general rule, the best focusing plane is determined by the reconstruction distance for which the criterion function presents a maximum or a minimum. To evaluate the robustness of these criteria, 13 criteria are compared with application on both amplitude and phase objects from off-axis holographic data...
May 1, 2017: Applied Optics
Meng Lyu, Caojin Yuan, Dayan Li, Guohai Situ
Typical methods of automatic estimation of focusing in digital holography calculate every single reconstructed frame to get a critical function and then ascertain the focal plane by finding the extreme value of that function. Here, we propose a digital holographic autofocusing method that computes the focused distance using the first longitudinal difference of the magnitude of the reconstructed image. We demonstrate the proposed method with both numerical simulations and optical experiments of amplitude-contrast and phase-contrast objects...
May 1, 2017: Applied Optics
A Vijayakumar, B Vinoth, Igor V Minin, Joseph Rosen, Oleg V Minin, Chau-Jern Cheng
In this study, we introduce what we believe is a novel holographic optical element called a chiral square Fresnel zone plate (CSFZP). The chirality is imposed on a square Fresnel zone plate (SFZP) using a nonclassical technique by rotating the half-period zones relative to one another. The rotation of the half-period zones, in turn, twists the side lobes of the diffraction pattern without altering the focusing properties inherent to a SFZP. As a consequence, the beam profile is hybrid, consisting of a strong central Gaussian focal spot with gradient force similar to that generated by a lens and twisted side lobes with orbital angular momentum...
May 1, 2017: Applied Optics
Ki-Hong Choi, Junkyu Yim, Sung-Wook Min
We propose the method that suppresses the defocus noise optically in the Fresnel incoherent correlation holographic system using a pinhole-polarizer (PP), which is made by punching a pinhole on the linear polarizer. The system configuration of this suggestion is based on the original system with optical-sectioning capability, which is realized by presenting the phase-pinhole on the phase-only spatial light modulator. In our system, the phase-pinhole is replaced with a PP. The replaced component is no longer programmable yet provides an affordable, simple, and light-efficient system configuration...
May 1, 2017: Applied Optics
Zhenxiang Zeng, Huadong Zheng, Yingjie Yu, Anand K Asundi, Sergiy Valyukh
Among the important features of holographic displays are the wide viewing angles and the full color of the reconstructed images. The present work focuses on achievement of both features. We propose an increased-viewing-angle full-color holographic display using two tiled phase-only spatial light modulators (SLMs), a 4f concave mirrors system, and a temporal-spatial multiplexing method. The 4f optical system consists of two concave mirrors and serves to increase the viewing angle. A temporal-spatial multiplexing synchronization control (TSMSC) method is developed to achieve a full-color image and to remove the color crosstalk of the image...
May 1, 2017: Applied Optics
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