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https://www.readbyqxmd.com/read/28454482/effects-of-environmental-factors-and-metallic-electrodes-on-ac-electrical-conduction-through-dna-molecule
#1
S Abdalla, A Obaid, F M Al-Marzouki
BACKGROUND: Deoxyribonucleic acid (DNA) is one of the best candidate materials for various device applications such as in electrodes for rechargeable batteries, biosensors, molecular electronics, medical- and biomedical-applications etc. Hence, it is worthwhile to examine the mechanism of charge transport in the DNA molecule, however, still a question without a clear answer is DNA a molecular conducting material (wire), semiconductor, or insulator? The answer, after the published data, is still ambiguous without any confirmed and clear scientific answer...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28454479/in-situ-immobilization-on-the-silica-gel-surface-and-adsorption-capacity-of-poly-n-4-carboxyphenyl-methacrylamide-on-toxic-metal-ions
#2
Elina Yanovska, Irina Savchenko, Dariusz Sternik, Olga Kychkiruk, Lidiya Ol'khovik, Iana Buriachenko
In situ immobilization of poly[N-(4-carboxyphenyl)methacrylamide] has been performed on silica gel surface. Infrared (IR) and mass spectroscopies as well as thermogravimetry (TG) analysis have been used to elucidate the structure of immobilized polymer. An adsorption capacity of the synthesized composite towards Cu(II), Pb(II), Mn(II), Fe(III), Co(II), and Ni(II) ions has been estimated. Adsorption activity to microquantities of Pb(II), Cu(II), and Ni(II) in a neutral aqueous medium has been observed.
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28454477/in-situ-analysis-of-oxygen-vacancies-and-band-alignment-in-hfo2-tin-structure-for-cmos-applications
#3
Da-Peng Xu, Lin-Jie Yu, Xu-Dong Chen, Lin Chen, Qing-Qing Sun, Hao Zhu, Hong-Liang Lu, Peng Zhou, Shi-Jin Ding, David Wei Zhang
The density of oxygen vacancies characterization in high-k/metal gate is significant for semiconductor device fabrication. In this work, a new approach was demonstrated to detect the density of oxygen vacancies by in situ x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurement. Moreover, the band alignment of the structure with optical band gap measured by spectroscopic ellipsometry (SE) and valence band offset by UPS were reported. The specific areal density of oxygen vacancies in high-k dielectric of HfO2/TiN was obtained by fitting the experiment data to be 8...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28454440/ffj-3-inhibits-pkm2-protein-expression-via-the-pi3k-akt-signaling-pathway-and-activates-the-mitochondrial-apoptosis-signaling-pathway-in-human-cancer-cells
#4
Dengyun Li, Xiaoli Wei, Mingming Ma, Huina Jia, Yu Zhang, Wenyi Kang, Tianxiao Wang, Xiaoyan Shi
Pyruvate kinase isoenzyme M2 (PKM2) has previously been identified as a tumor biomarker and potential therapeutic target for the treatment of cancer. In the present study, FFJ-3, a structurally modified version of mollugin, an extract of the Traditional Chinese herbal medicine Rubia tinctorum (madder) was used in order to determine the anticancer activity of the compound and investigate the potential mechanisms underlying this effect in human cancer cells. The results of the present study revealed that FFJ-3 inhibited the survival of HepG2 human hepatoma cells, MCF-7 human breast cancer cells and A549 human lung adenocarcinoma cells using the MTT assay...
April 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454428/the-regulation-of-proteins-associated-with-the-cytoskeleton-by-hepatitis-b-virus-x-protein-during-hepatocarcinogenesis
#5
Fanyun Kong, Hongjuan You, Renxian Tang, Kuiyang Zheng
Hepatocellular carcinoma (HCC) is a major malignant disease worldwide, and chronic hepatitis B virus (HBV) infection is one of the primary causes for this type of cancer. Hepatitis B virus X protein (HBx) is a non-structural protein encoded by the viral genome that has significant effects on the pathogenesis of HCC. With the development of high-throughput assays and technologies, the abnormal HBx-induced expression of certain cellular proteins with assorted biological functions has been investigated. These target proteins identified by various methods include specific proteins associated with the cellular cytoskeleton, which contribute to HBx-induced hepatocarcinogenesis...
April 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454295/nima-related-kinase-2-regulates-hepatocellular-carcinoma-cell-growth-and-proliferation
#6
Xiao-Bo Lai, Yu-Qiang Nie, Hong-Li Huang, Ying-Fei Li, Chuang-Yu Cao, Hui Yang, Bo Shen, Zhi-Qiang Feng
NIMA-related kinase 2 (Nek2) is often upregulated in human cancer and is important in regulating the cell cycle and gene expression, and maintaining centrosomal structure and function. The present study aimed to investigate the expression pattern, clinical significance, and biological function of Nek2 in hepatocellular carcinoma (HCC). mRNA and protein levels of Nek2 were examined in HCC and corresponding normal liver tissues. The MTT and soft agar colony formation assays, and flow cytometry were employed to assess the roles of Nek2 in cell proliferation and growth...
March 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454259/intentional-marginal-resection-of-periosteal-osteosarcoma-in-combination-with-neoadjuvant-chemotherapy-a-report-of-two-cases-and-a-review-of-the-literature
#7
Yu Chen, Song-Feng Xu, Ming Xu, Xiu-Chun Yu
A wide resection of the tumor with or without chemotherapy is the treatment of choice for periosteal osteosarcoma (PO) of the extremities, however, post-operative limb function and quality of life could be compromised. The present study reports two cases of 14-year-old boys who presented with progressively enlarging masses in their right knee regions. Computed tomography and magnetic resonance imaging scans indicated a fusiform space-occupying mass encircling the bone cortex, with stippled calcification. A diagnosis of PO was suspected...
March 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454212/reciprocal-regulation-between-micrornas-and-epigenetic-machinery-in-colorectal-cancer
#8
Feng Wang, Yanlei Ma, Huamin Wang, Huanlong Qin
Epigenetics encompasses changes in DNA methylation, histone and chromatin structure, and non-coding RNAs, specifically microRNA (miRNA) expression. Recent advances in the rapidly evolving field of colorectal cancer (CRC) epigenetics have revealed a complicated network of reciprocal interconnections between miRNAs and other epigenetic machinery. On the one hand, miRNA expression may be regulated by epigenetic mechanisms including DNA methylation and histone modifications. However, miRNAs may affect the epigenetic machinery by directly targeting its enzymatic components...
March 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454171/depth-resolution-enhancement-of-terahertz-deconvolution-by-autoregressive-spectral-extrapolation
#9
Junliang Dong, Alexandre Locquet, D S Citrin
This Letter presents a method for enhancing the depth resolution of terahertz deconvolution based on autoregressive (AR) spectral extrapolation. The terahertz frequency components with a high signal-to-noise ratio (SNR) are modeled with an AR process, and the missing frequency components in the regions with low SNRs are extrapolated based on the AR model. In this way, the entire terahertz frequency spectrum of the impulse response function, corresponding to the material structure, is recovered. This method, which is verified numerically and experimentally, is able to provide a "quasi-ideal" impulse response function and, therefore, greatly enhances the depth resolution for characterizing optically thin layers in the terahertz regime...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454168/laser-waveform-control-of-extreme-ultraviolet-high-harmonics-from-solids
#10
Yong Sing You, Mengxi Wu, Yanchun Yin, Andrew Chew, Xiaoming Ren, Shima Gholam-Mirzaei, Dana A Browne, Michael Chini, Zenghu Chang, Kenneth J Schafer, Mette B Gaarde, Shambhu Ghimire
Solid-state high-harmonic sources offer the possibility of compact, high-repetition-rate attosecond light emitters. However, the time structure of high harmonics must be characterized at the sub-cycle level. We use strong two-cycle laser pulses to directly control the time-dependent nonlinear current in single-crystal MgO, leading to the generation of extreme ultraviolet harmonics. We find that harmonics are delayed with respect to each other, yielding an atto-chirp, the value of which depends on the laser field strength...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454155/efficient-terahertz-anti-reflection-properties-of-metallic-anti-dot-structures
#11
Kumar Neeraj, Samiran Choudhury, Debanjan Polley, Rakhi Acharya, Jaivardhan Sinha, Anjan Barman, Rajib Kumar Mitra
We report the use of micrometer-sized copper (Cu) anti-dot structures as a novel terahertz (THz) anti-reflection coating (ARC) material and their superior performance over conventionally used metallic (Cu) thin films. Cu anti-dot structures of two different thicknesses (7 and 10 nm) with varying anti-dot diameters (100, 200, and 300 μm, inter-anti-dot separation fixed at 100 μm) are deposited on silicon substrates by RF magnetron sputtering and e-beam evaporation. The anti-reflection performance of these samples is studied in the frequency range of 0...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454153/akhmediev-breathers-and-peregrine-solitary-waves-in-a-quadratic-medium
#12
Fabio Baronio
I investigate the formation of optical localized nonlinear structures, evolving upon a non-zero background plane wave in a dispersive quadratic medium. I show the existence of quadratic Akhmediev breathers and Peregrine solitary waves in the regime of cascading second-harmonic generation. This finding opens a novel path for the excitation of extreme rogue waves and for the description of modulation instability in quadratic nonlinear optics.
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454144/automatic-focusing-for-multisectional-objects-in-digital-holography-using-the-structure-tensor
#13
Zhenbo Ren, Ni Chen, Edmund Y Lam
Determining the axial position of the recorded object in digital holography is a crucial step for image reconstruction. When multiple discrete sections of a three-dimensional object are overlapping each other, this issue becomes more challenging. In this Letter, an autofocusing algorithm using the structure tensor and its eigenvalues is proposed. This method can extract the focal distance of each section for a multi-sectional object irrespective of whether the sections are overlapping or not. We validate the applicability of the proposed technique with synthesized and experimental data using two types of holographic systems...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454136/laser-writing-of-nonlinear-optical-properties-in-silver-doped-phosphate-glass
#14
E O Smetanina, B Chimier, Y Petit, A Royon, T Cardinal, L Canioni, G Duchateau
The formation of both local second- and third-harmonic generations (SHG and THG) induced by a train of femtosecond laser pulses in silver-doped phosphate glasses is addressed. Based on modeling calculations, including various diffusion and kinetic processes, THG is shown to result from the formation of silver clusters. The latter organize into a ring-shape structure, leading to the emergence of a static electric field. By breaking the glass centro-symmetry, this field gives rise to a local effective second-order susceptibility, inducing SHG...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454132/broadband-single-mode-single-polarization-passive-fully-aperiodic-large-pitch-fibers
#15
Rémi du Jeu, Romain Dauliat, Dia Darwich, Aurélien Benoit, Raphaël Jamier, Kay Schuster, Philippe Roy
Two evolutions of fully aperiodic large-pitch fiber designs employing few stress-applying parts are presented. The induced elasto-optic stress discriminates the two orthogonal polarization modes (LP<sub>01x</sub> and LP<sub>01y</sub>) of the fundamental mode, selectively delocalizing one of them into the cladding via a suitable coupling to one or several cladding modes. This ensures the propagation of a single linear polarization mode. For the largest core dimensions, however, the applied stress can strongly influence the intensity distributions of core modes, and a tailored design process must thwart this...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454127/sn-based-waveguide-p-i-n-photodetector-with-strained-gesn-ge-multiple-quantum-well-active-layer
#16
Yu-Hui Huang, Guo-En Chang, Hui Li, H H Cheng
We report on Sn-based p-i-n waveguide photodetectors (WGPD) with a pseudomorphic GeSn/Ge multiple-quantum-well (MQW) active layer on a Ge-buffered Si substrate. A reduced dark-current density of 59  mA/cm<sup>2</sup> was obtained at a reverse bias of 1 V due to the suppressed strain relaxation in the GeSn/Ge active layer. Responsivity experiments revealed an extended photodetection range covering the O, E, S, C, and L telecommunication bands completely due to the bandgap reduction resulting from Sn-alloying...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28454106/different-patterns-of-age-related-central-olfactory-decline-in-men-and-women-as-quantified-by-olfactory-fmri
#17
Brittany Martinez, Prasanna Karunanayaka, Jianli Wang, Michael J Tobia, Megha Vasavada, Paul J Eslinger, Qing X Yang
Age-related olfactory decline, or presbyosmia, is a prevalent condition with potentially devastating consequences on both quality of life and safety. Despite clear evidence for this decline, it is unknown whether presbyosmia is sex-dependent and also whether it is due to central or peripheral olfactory system deterioration. Therefore, the goals of this study were to investigate the neurofunctional substrate of olfactory decline and examine its relationship to age and sex in thirty-seven (18 women, 19 men) healthy older participants using olfactory functional MRI (fMRI)...
April 8, 2017: Oncotarget
https://www.readbyqxmd.com/read/28454078/new-complexes-of-cu-ii-with-dipicolinate-and-pyridyl-based-ligands-an-experimental-and-dft-approach
#18
Florencia Luzardo, Natalia Álvarez, Carlos Kremer, Andrea S S de Camargo, Jorge S Gancheff
The three novel mononuclear copper(II) complexes with dipicolinate and pyridyl-based ligands [Cu(dipic)(L)(OH2)] (L=4-picoline, vinylpyridine, 4-styrylpyridine; dipic(2-)=dipicolinate) were afforded and structurally characterized. X-ray diffraction studies accounted for slight distorted square-pyramidal structures in which the dianion dipic(2-) acts as a tridentate ligand in a mer-fashion, the N-donor species occupy an in-plane position, and a water molecule was detected apically coordinated. To assess the effect of the nature of the pyridyl-substituent (para position) on electronic properties, other complexes were also synthesized: [Cu(dipic)(py)(OH2)], [{Cu(dipic)(OH2)}2(μ-pyz)] and [{Cu(dipic)(OH2)}(μ-pypy){Cu(dipic)}] (py=pyridine, pyz=pyrazine, pypy=(E)-1,2-bis(pyridine-4-yl)ethane)...
April 8, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28454074/photocatalytic-degradation-of-dye-using-ceo2-scb-composite-catalysts
#19
Duangdao Channei, Auppatham Nakaruk, Sukon Phanichphant
The main task of the present work is to enhance the photocatalytic degradation efficiency of methylene blue (MB) by using CeO2/sugarcane bagasse (SCB) composite catalysts. Homogeneous precipitation method was used to synthesis CeO2-SCB composite catalysts by adding SCB powder to precursor solution of Ce base-metal. The structural analytical data indicated the pure cubic fluorite structure of CeO2. Morphological images revealed the coating of CeO2 layer on high surface area of SCB core-shell. The chemical analysis presented spectrum of the Ce 3d in CeO2/SCB sample existed in the form of the Ce(3+) and Ce(4+) mixed- valence states...
April 22, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28454073/low-temperature-raman-spectra-of-the-2-%C3%AE-methylbenzylamino-5-nitropyridine-crystal
#20
G S Pinheiro, M N G Ferreira Júnior, A O Dos Santos, P T C Freire, J A Lima, C E S Nogueira, L P Cardoso, J N Sherwood, C M R Remédios
The polar organic 2-(α-methylbenzylamino)-5-nitropyridine crystal (MBANP) has been studied by Raman spectroscopy at low temperatures (from 300 to 10K). The effect of temperature change on the vibrational spectrum is discussed with the aid of DFT calculations. The behavior of the Raman spectra indicates that MBANP molecules present a different conformation at low temperatures associated with the rotation of the phenyl and pyridine rings. Temperature-dependent X-ray measurements and differential scanning calorimetry (DSC) analysis were utilized as complementary techniques to investigate the structural stability of MBANP crystal...
April 20, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
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