Viewpoint switching in multiview videos using SP-frames

The distinguishing feature of multiview video lies in the interactivity, which allows users to select their favourite viewpoint. It switches bitstream at a particular view when necessary instead of transmitting all the views. The new SP-frame in H.264 is originally developed for multiple bit-rate streaming with the support of seamless switching. The SP-frame can also be directly employed in the viewpoint switching of multiview videos. Notwithstanding the guarantee of seamless switching using SP-frames, the cost is the bulky size of secondary SP-frames. This induces a significant amount of additional space or bandwidth for storage or transmission, especially for the multiview scenario. For this reason, a new motion estimation and compensation technique operating in the quantized transform (QDCT) domain is designed for coding secondary SP-frame in this paper. Our proposed work aims at keeping the secondary SP-frames as small as possible without affecting the size of primary SP-frames by incorporating QDCT-domain motion estimation and compensation in the secondary SP-frame coding. Simulation results show that the size of secondary SP-frames can be reduced remarkably in viewpoint switching. Index Terms — Multiview, viewpoint switching, SP-frame, QDCT-domain, motion estimatio

The Enhanced metastatic potential of hepatocellular carcinoma (HCC) cells with sorafenib resistance

Acquired resistance towards sorafenib treatment was found in HCC patients, which results in poor prognosis. To investigate the enhanced metastatic potential of sorafenib resistance cells, sorafenib-resistant (SorR) cell lines were established by long-term exposure of the HCC cells to the maximum tolerated dose of sorafenib. Cell proliferation assay and qPCR of ABC transporter genes (ABCC1-3) were first performed to confirm the resistance of cells. Migration and invasion assays, and immunoblotting analysis on the expression of epithelial to mesenchymal transition (EMT) regulatory proteins were performed to study the metastatic potential of SorR cells. The expression of CD44 and CD133 were studied by flow cytometry and the gene expressions of pluripotency factors were studied by qPCR to demonstrate the enrichment of cancer stem cells (CSCs) in SorR cells. Control (CTL) and SorR cells were also injected orthotopically to the livers of NOD-SCID mice to investigate the development of lung metastasis. Increased expressions of ABCC1-3 were found in SorR cells. Enhanced migratory and invasive abilities of SorR cells were observed. The changes in expression of EMT regulatory proteins demonstrated an activation of the EMT process in SorR cells. Enriched proportion of CD44+ and CD44+CD133 + cells were also observed in SorR cells. All (8/8) mice injected with SorR cells demonstrated lung metastasis whereas only 1/8 mouse injected with CTL cells showed lung metastasis. HCC cells with sorafenib resistance demonstrated a higher metastatic potential, which may be due to the activated EMT process. Enriched CSCs were also demonstrated in the sorafenib resistant cells. This study suggests that advanced HCC patients with acquired sorafenib resistance may have enhanced tumor growth or distant metastasis, which raises the concern of long-term sorafenib treatment in advanced HCC patients who have developed resistance of sorafenib. © 2013 Chow et al.published_or_final_versio

AluScan: a method for genome-wide scanning of sequence and structure variations in the human genome

<p>Abstract</p> <p>Background</p> <p>To complement next-generation sequencing technologies, there is a pressing need for efficient pre-sequencing capture methods with reduced costs and DNA requirement. The Alu family of short interspersed nucleotide elements is the most abundant type of transposable elements in the human genome and a recognized source of genome instability. With over one million Alu elements distributed throughout the genome, they are well positioned to facilitate genome-wide sequence amplification and capture of regions likely to harbor genetic variation hotspots of biological relevance.</p> <p>Results</p> <p>Here we report on the use of inter-Alu PCR with an enhanced range of amplicons in conjunction with next-generation sequencing to generate an Alu-anchored scan, or 'AluScan', of DNA sequences between Alu transposons, where Alu consensus sequence-based 'H-type' PCR primers that elongate outward from the head of an Alu element are combined with 'T-type' primers elongating from the poly-A containing tail to achieve huge amplicon range. To illustrate the method, glioma DNA was compared with white blood cell control DNA of the same patient by means of AluScan. The over 10 Mb sequences obtained, derived from more than 8,000 genes spread over all the chromosomes, revealed a highly reproducible capture of genomic sequences enriched in genic sequences and cancer candidate gene regions. Requiring only sub-micrograms of sample DNA, the power of AluScan as a discovery tool for genetic variations was demonstrated by the identification of 357 instances of loss of heterozygosity, 341 somatic indels, 274 somatic SNVs, and seven potential somatic SNV hotspots between control and glioma DNA.</p> <p>Conclusions</p> <p>AluScan, implemented with just a small number of H-type and T-type inter-Alu PCR primers, provides an effective capture of a diversity of genome-wide sequences for analysis. The method, by enabling an examination of gene-enriched regions containing exons, introns, and intergenic sequences with modest capture and sequencing costs, computation workload and DNA sample requirement is particularly well suited for accelerating the discovery of somatic mutations, as well as analysis of disease-predisposing germline polymorphisms, by making possible the comparative genome-wide scanning of DNA sequences from large human cohorts.</p

A base-stabilized silylene-promoted C(sp³)-H borylation and H₂ activation

Treatment of the amidinato amidosilylene [L{(Me3Si)2N}Si:] [1, L = PhC(NtBu)2] with a slight excess of borane-tetrahydrofuran complex [BH3·THF] in toluene at room temperature afforded the silylene-borane adduct [L{(Me3Si)2N}Si:→BH3] (2). A triflate substituent was introduced on the boron center by reacting 2 with methyl triflate [MeOTf] (OTf = OSO2CF3) in toluene at room temperature to form [L{(Me3Si)2N}Si:→BH2OTf] (3), with the elimination of CH4 gas. The intramolecular C(sp3)-H borylation and H2 elimination occurred by reacting complex 3 with 1 in refluxing toluene to form a C-B bond in the resulting silylene-boronium ion 5. Complex 5 activated H2 gas or NH3BH3 at room temperature to form silylene-borane adduct 2 and [L{(Me3Si)2N}Si-H]OTf. Additionally, the reaction of 5 with H2 was studied through density functional theory calculations.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Accepted versionThis work is supported by an ASTAR SERC PSF grant (1421200081), the Ministry of Education, Academic Research Fund Tier 1 (RG 121/17), and the National Research Foundation Singapore NRF-ANR (NRF2018-NRF-ANR026 Si-POP)

Theoretical examination of competitive β-radical-induced cleavages of N-C

Selective cleavages of N-CThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Charge transfer reactions between gas-phase hydrated electrons, molecular oxygen and carbon dioxide at temperatures of 80-300 K

(VLID)4795251Version of recor

Reductions of Oxygen, Carbon Dioxide, and Acetonitrile by the Magnesium(II)/Magnesium(I) Couple in Aqueous Media: Theoretical Insights from a Nano-Sized Water Droplet

Reductions of O₂, CO₂, and CH₃CN by the half-reaction of the Mg­(II)/Mg­(I) couple (Mg²⁺ + e^– → Mg^+•) confined in a nanosized water droplet ([Mg­(H₂O)₁₆]^•+) have been examined theoretically by means of density functional theory based molecular dynamics methods. The present works have revealed many intriguing aspects of the reaction dynamics of the water clusters within several picoseconds or even in subpicoseconds. The reduction of O₂ requires an overall doublet spin state of the system. The reductions of CO₂ and CH₃CN are facilitated by their bending vibrations and the electron-transfer processes complete within 0.5 ps. For all reactions studied, the radical anions, i.e., O₂^•–, CO₂^•–, and CH₃CN^•–, are initially formed on the cluster surface. O₂^•– and CO₂^•– can integrate into the clusters due to their high hydrophilicity. They are either solvated in the second solvation shell of Mg²⁺ as a solvent-separated ion pair (ssip) or directly coordinated to Mg²⁺ as a contact-ion pair (cip) having the ¹η-[MgO₂]^•+ and ¹η-[MgOCO]^•+ coordination modes. The ¹η-[MgO₂]^•+ core is more crowded than the ¹η-[MgOCO]^•+ core. The reaction enthalpies of the formation of ssip and cip of [Mg­(CO₂)­(H₂O)₁₆]^•+ are −36 ± 4 kJ mol^–1 and −30 ± 9 kJ mol^–1, respectively, which were estimated based on the average temperature changes during the ion–molecule reaction between CO₂ and [Mg­(H₂O)₁₆]^•+. The values for the formation of ssip and cip of [Mg­(O₂)­(H₂O)₁₆]^•+ are estimated to be −112 ± 18 kJ mol^–1 and −128 ± 28 kJ mol^–1, respectively. CH₃CN^•– undergoes protonation spontaneously to form the hydrophobic [CH₃CN, H]^•. Both CH₃CN and [CH₃CN, H]^• cannot efficiently penetrate into the clusters with activation barriers of 22 kJ mol^–1 and ∼40 kJ mol^–1, respectively. These results provide fundamental insights into the solvation dynamics of the Mg²⁺/Mg^•+ couple on the molecular level

Formation of n -&gt; pi(+)interaction facilitating dissociative electron transfer in isolated tyrosine-containing molecular peptide radical cations

Contains fulltext : 225052.pdf (publisher's version ) (Closed access

Hydration Leads to Efficient Reactions of the Carbonate Radical Anion with Hydrogen Chloride in the Gas Phase

The carbonate radical anion CO₃^•– is a key intermediate in tropospheric anion chemistry. Despite its radical character, only a small number of reactions have been reported in the literature. Here we investigate the gas-phase reactions of CO₃^•– and CO₃^•–(H₂O) with HCl under ultrahigh vacuum conditions. Bare CO₃^•– forms OHCl^•– with a rate constant of 4.2 × 10^–12 cm³ s^–1, which corresponds to an efficiency of only 0.4%. Hydration accelerates the reaction, and ligand exchange of H₂O against HCl proceeds with a rate of 2.7 × 10^–10 cm³ s^–1. Quantum chemical calculations reveal that OHCl^•– is best described as an OH^• hydrogen bonded to Cl^–, while the ligand exchange product is Cl^–(HCO₃^•). Under tropospheric conditions, where CO₃^•–(H₂O) is the dominant species, Cl^–(HCO₃^•) is efficiently formed. These reactions must be included in models of tropospheric anion chemistry

Infrared Spectroscopy of SizeSelected Hydrated Carbon Dioxide Radical Anions CO2.-(H2O)n (n=2-61) in the C-O Stretch Region

Understanding the intrinsic properties of the hydrated carbon dioxide radical anions CO2.-(H2O)n is relevant for electrochemical carbon dioxide functionalization. CO2.-(H2O)n (n=2-61) is investigated by using infrared action spectroscopy in the 1150-2220cm-1 region in an ICR (ion cyclotron resonance) cell cooled to T=80K. The spectra show an absorption band around 1280cm-1, which is assigned to the symmetric C-O stretching vibration s. It blueshifts with increasing cluster size, reaching the bulk value, within the experimental linewidth, for n=20. The antisymmetric C-O vibration as is strongly coupled with the water bending mode 2, causing a broad feature at approximately 1650cm-1. For larger clusters, an additional broad and weak band appears above 1900cm-1 similar to bulk water, which is assigned to a combination band of water bending and libration modes. Quantum chemical calculations provide insight into the interaction of CO2.- with the hydrogenbonding network.(VLID)4466113Version of recor