scholarly journals Vector Optical Beam with Controllable Variation of Polarization during Propagation in Free Space: A Review

2021 ◽  
Vol 11 (22) ◽  
pp. 10664
Author(s):  
Wen-Yue Wang ◽  
Tian-Yu Cheng ◽  
Zhen-Xu Bai ◽  
Shuo Liu ◽  
Jia-Qi Lü
Keyword(s):  
Free Space ◽  
Real Space ◽  
Spatial Spectrum ◽  
Optical Beam ◽  
Longitudinal Distribution ◽  
Laser Machining ◽  
Amplitude Difference ◽  
Optical Beams ◽  
Significant Attention

The vector optical beam with longitudinally varying polarization during propagation in free space has attracted significant attention in recent years. Compared with traditional vector optical beams with inhomogeneous distribution of polarization in the transverse plane, manipulating the longitudinal distribution of polarization provides a new dimension for the expansion of the applications of vector optical beams in volume laser machining, longitudinal detection, and in vivo micromanipulation. Two theoretical strategies for achieving this unique optical beam are presented in the way of constructing the longitudinally varying phase difference and amplitude difference. Relevant generation methods are reviewed which can be divided into the modulation of complex amplitude in real space and the filtering of the spatial spectrum. In addition, current problems and prospects for vector optical beams with longitudinally varying polarization are discussed.

scholarly journals Efficient Reversible Data Hiding Scheme for AMBTC-Compressed Images

2021 ◽  
Vol 11 (15) ◽  
pp. 6741
Author(s):  
Chia-Chen Lin ◽  
Thai-Son Nguyen ◽  
Chin-Chen Chang ◽  
Wen-Chi Chang
Keyword(s):  
Data Hiding ◽  
Free Space ◽  
Reversible Data Hiding ◽  
Secret Message ◽  
Embedding Capacity ◽  
Absolute Moment ◽  
Compressed Images ◽  
High Embedding Capacity ◽  
Significant Attention ◽  
Efficiency Rate

Reversible data hiding has attracted significant attention from researchers because it can extract an embedded secret message correctly and recover a cover image without distortion. In this paper, a novel, efficient reversible data hiding scheme is proposed for absolute moment block truncation code (AMBTC) compressed images. The proposed scheme is based on the high correlation of neighboring values in two mean tables of AMBTC-compressed images to further losslessly encode these values and create free space for containing a secret message. Experimental results demonstrated that the proposed scheme obtained a high embedding capacity and guaranteed the same PSNRs as the traditional AMBTC algorithm. In addition, the proposed scheme achieved a higher embedding capacity and higher efficiency rate than those of some previous schemes while maintaining an acceptable bit rate.

scholarly journals Synthesis of Novel Pyran Fragments to Incorporate into Peloruside Analogues

2021 ◽  
Author(s):  
◽  
Oliver Bayley
Keyword(s):  
Cell Division ◽  
Scale Up ◽  
Great Promise ◽  
Peloruside A ◽  
Bioactive Secondary Metabolite ◽  
Mycale Hentscheli ◽  
Significant Attention ◽  
Simple Carbohydrate

<p>Cancer is currently the second largest cause of death globally, leading to a high demand for new and effective chemotherapeutics. For years, natural products have been used as a source of new bioactive compounds; of particular interest in this context, as a source of new chemotherapeutics. One chemotherapeutic candidate which has attracted significant attention in synthetic and medicinal chemistry communities, is peloruside A. Peloruside A is a bioactive secondary metabolite isolated from the New Zealand marine sponge Mycale hentscheli. Since its discovery, peloruside A has shown great promise in cancer studies both in vivo and in vitro with effects observed even at nanomolar concentrations. These chemotherapeutic effects have been shown to occur by halting cell division at the G2/M checkpoint via microtubule stabilisation. Of particular interest is that this stabilisation occurs in a manner distinct from that of the already established taxane class of microtubule stabilising drugs. This means that peloruside A is able to offer both inhibition of cell division in Taxol® resistant cells and synergistic inhibition alongside the current taxane drugs. Since peloruside A is not abundantly available from its natural source, there is a strong incentive for the development of new synthetic strategies for peloruside A production. Unfortunately attempts at aquaculture and attempts at developing an industrial scale synthesis have both proven unsuccessful thus far. In an attempt to overcome some of the difficulties with the scale up of peloruside, analogues have been developed that are intended to have similar bioactivity to peloruside A but simpler, more concise, synthetic routes. These analogues will also enable further elucidation of the binding properties of peloruside A. This project focuses on the generation of a functionalised pyran fragment, starting from a simple carbohydrate, that may be incorporated into the proposed analogues.</p>

Coherent self-control of free space optical beams with integrated silicon photonic meshes

2021 ◽  
Author(s):  
Maziyar Milanizadeh ◽  
Fabio Toso ◽  
Giorgio Ferrari ◽  
Tigers Jonuzi ◽  
David A. B. Miller ◽  
...  
Keyword(s):  
Free Space ◽  
Self Control ◽  
Free Space Optical ◽  
Silicon Photonic ◽  
Optical Beams

Applications of Advanced Nanotechnology in Stem Cell Research

2021 ◽  
Vol 13 (2) ◽  
pp. 188-198
Author(s):  
Chih-Hui Yang ◽  
Shu-Ling Huang ◽  
Yi-Ting Wang ◽  
Chun-Ho Chang ◽  
Ya-Chi Tsai ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Research ◽  
Biomedical Applications ◽  
Academic Research ◽  
Review Article ◽  
Technical Problems ◽  
Biomedical Industry ◽  
Significant Attention

Nanotechnology gives rise to new breakthroughs and developments in various fields. The applications of advanced nanotechnology may resolve the current technical problems encountered in stem cell research. Nanotechnology has gained significant attention in both academic research and the biomedical industry in recent years. In this mini-review article, the progress of nanotechnology-aided stem cell studies has been surveyed, and the in vitro and in vivo applications of nanotechnology have been introduced. The in vitro studies are divided into three categories: isolation, detection, and regulation. The progress of in vivo studies and trends in biomedical applications have also been addressed.

scholarly journals Biocompatible Organic Coatings Based on Bisphosphonic Acid RGD-Derivatives for PEO-Modified Titanium Implants

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 229 ◽  
Author(s):  
Lyudmila V. Parfenova ◽  
Elena S. Lukina ◽  
Zulfia R. Galimshina ◽  
Guzel U. Gil’fanova ◽  
Veta R. Mukaeva ◽  
...  
Keyword(s):  
Titanium Implants ◽  
Biologically Active ◽  
Hybrid Molecules ◽  
Electrolytic Oxidation ◽  
Coated Surface ◽  
Plasma Electrolytic ◽  
Chemical Cross Linking ◽  
Significant Attention

Currently, significant attention is attracted to the problem of the development of the specific architecture and composition of the surface layer in order to control the biocompatibility of implants made of titanium and its alloys. The titanium surface properties can be tuned both by creating an inorganic sublayer with the desired morphology and by organic top coating contributing to bioactivity. In this work, we developed a composite biologically active coatings based on hybrid molecules obtained by chemical cross-linking of amino acid bisphosphonates with a linear tripeptide RGD, in combination with inorganic porous sublayer created on titanium by plasma electrolytic oxidation (PEO). After the addition of organic molecules, the PEO coated surface gets nobler, but corrosion currents increase. In vitro studies on proliferation and viability of fibroblasts, mesenchymal stem cells and osteoblast-like cells showed the significant dependence of the molecule bioactivity on the structure of bisphosphonate anchor and the linker. Several RGD-modified bisphosphonates of β-alanine, γ-aminobutyric and ε-aminocaproic acids with BMPS or SMCC linkers can be recommended as promising candidates for further in vivo research.

High bitrate free-space communicator using automatic nonlinear all-optical beam tracking

2005 ◽  
Author(s):  
Alexander E. Dudelzak ◽  
Alexander S. Kuzhelev ◽  
Daniel Gratton ◽  
Louis Hotte ◽  
Yoshinori Arimoto
Keyword(s):  
Free Space ◽  
Optical Beam ◽  
All Optical ◽  
Beam Tracking

scholarly journals Voxel-Based Imaging of Translocator Protein 18Kda (TSPO) in High-Resolution PET

2013 ◽  
Vol 33 (3) ◽  
pp. 348-350 ◽  
Author(s):  
Ji Hyun Ko ◽  
Yuko Koshimori ◽  
Romina Mizrahi ◽  
Pablo Rusjan ◽  
Alan A Wilson ◽  
...  
Keyword(s):  
Relative Equilibrium ◽  
Compartment Model ◽  
Graphical Analysis ◽  
Translocator Protein ◽  
Proof Of Concept ◽  
Tissue Compartment ◽  
Potential Biomarker ◽  
Translocator Protein 18 Kda ◽  
Significant Attention

In vivo imaging of translocator protein 18 kDa (TSPO) has received significant attention as potential biomarker of microglia activation. Several radioligands have been designed with improved properties. Our group recently developed an 18F-labeled TSPO ligand, [18F]-FEPPA, and confirmed its reliability with a 2-tissue compartment model. Here, we extended, in a group of healthy subjects, its suitability for use in voxel-based analysis with the newly proposed graphical analysis approach, Relative-Equilibrium-Gjedde-Patlak (REGP) plot. The REGP plot successfully replicated the total distribution volumes estimated by the 2-tissue compartment model. We also showed its proof-of-concept in a patient with possible meningioma showing increased [18F]-FEPPA total distribution volume.

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