Gingivo-buccal oral squamous cell carcinoma (OSCC-GB), an anatomical and clinical subtype of head and neck squamous cell carcinoma (HNSCC), is prevalent in regions where tobacco-chewing is common. ...Exome sequencing (n=50) and recurrence testing (n=60) reveals that some significantly and frequently altered genes are specific to OSCC-GB (USP9X, MLL4, ARID2, UNC13C and TRPM3), while some others are shared with HNSCC (for example, TP53, FAT1, CASP8, HRAS and NOTCH1). We also find new genes with recurrent amplifications (for example, DROSHA, YAP1) or homozygous deletions (for example, DDX3X) in OSCC-GB. We find a high proportion of C>G transversions among tobacco users with high numbers of mutations. Many pathways that are enriched for genomic alterations are specific to OSCC-GB. Our work reveals molecular subtypes with distinctive mutational profiles such as patients predominantly harbouring mutations in CASP8 with or without mutations in FAT1. Mean duration of disease-free survival is significantly elevated in some molecular subgroups. These findings open new avenues for biological characterization and exploration of therapies.
Polypyrrole (PPy) is embedded in polyvinyl alcohol (PVA) matrix to give a homogeneous composite solution by dispersing PPy in PVA solution. Scanning electron microscopic (SEM) study on the film ...prepared from the composite solution shows uniform distribution of nearly spherical shaped PPy grains of average diameter of 20 nm. The X-ray diffraction (XRD), UV–visible and Fourier transform infra-red (FTIR) spectroscopic characterizations of the composite film are carried out for structural and optical properties. The enhanced thermal stability of the PPy–PVA composite film is confirmed by thermogravimetric analysis (TGA). XRD shows signature of amorphous nature for PVA along with some crystallinity arising for PPy. UV–visible absorption spectrum shows two absorption peaks for π–π* and polaronic transition; FTIR spectrum suggests cross linking between PPy and PVA. Studies on sensing of the PPy–PVA composite film for ethanol, ammonia, toluene, chloroform and acetone vapors at room temperature (300 K) are done for comparison. The composite film shows best response among all these vapors towards ethanol requiring smallest response time.
•Fabrication of superhydrophobic aluminum alloy surfaces by chemical etching followed by organic molecule passivation.•The formation of flake-like micro-nanostructure morphology of the low surface ...energy aluminum stearate on aluminum.•The complementary corrosion studies by polarization resistance and electrochemical impedance spectroscopy (EIS).•The modulus of impedanceis found to be 70 times larger for the superhydrophobic surfaces compared with the as-received aluminum alloy surface.
Superhydrophobic aluminum alloy surfaces are obtained by chemical etching using 1M NaOH solution followed by passivation using 0.01M ethanolic stearic acid (SA) solution. The formation of low surface energy aluminum stearate takes place during the passivation process between stearic acid and hydroxyl group-terminated aluminum alloy surfaces. A schematic model of the SA passivation process on the OH terminated Al-surfaces is presented in this work. The flake-like micro-nanostructure morphology of the low surface energy aluminum stearate increases the water contact angle by more than 150°, demonstrating the superhydrophobic properties. The corrosion current density reduces and polarization resistance increases systematically with increasing passivation time. The polarization resistance, calculated from the Tafel curve of the superhydrophobic surfaces prepared by stearic acid passivation for 60min, is determined to be 137 times larger than that of the as-received aluminum alloy substrate. Similarly, the modulus of impedance, as-determined from electrochemical impedance spectroscopy (EIS), is found to be 70 times larger for the superhydrophobic surfaces compared with the as-received aluminum alloy surface. These results demonstrate that the superhydrophobic aluminum alloy surfaces created by chemical etching followed by passivation have superior corrosion resistance properties than the as-receive aluminum alloy substrate.
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•Superhydrophobic copper surfaces by a one-step electrochemical modification process in an ethanolic stearic acid solution.•Analysis of the corrosion properties of as-received, ...hydrophobic and superhydrophobic copper surfaces.•The corrosion resistance of the superhydrophobic surface is found to be 1220kΩcm2 as compared to as-received bare copper surface 1kΩcm2.
Superhydrophobic copper surfaces have been prepared by a one-step electrochemical modification process in an ethanolic stearic acid solution. In this work, the corrosion properties of hydrophobic copper surface and superhydrophobic copper surfaces were analyzed by means of electrochemical analyses and compared with that of as-received bare copper substrate. The decrease of corrosion current density (icorr) as well as the increase of polarization resistance (Rp) obtained from potentiodynamic polarization curves revealed that the superhydrophobic film on the copper surfaces improved the corrosion resistance performance of the copper substrate.
•3% and 5% Ni doped ZnO nanoparticles are grown by a ball milling technique.•3% doped ZnO nanoparticles exhibit room temperature high magnetic moment that changes with milling time.•Optical and ...magnetic properties of doped ZnO nanoparticles are correlated well.•Mechanism of the magnetic interaction is quantitatively analyzed using a bound magnetic polar model.•Direct correlation between the defects in doped ZnO and magnetic moment is demonstrated.
We report on the room temperature ferromagnetism in the Zn1−xNixO (x=0, 0.03 and 0.05) nanoparticles (NPs) synthesized by a ball milling technique. X-ray diffraction analysis confirms the single crystalline, wurtzite ZnO structure for the 3% Ni doped ZnO NPs for higher milling time. HRTEM lattice image and SAED pattern show that the doped NPs are single crystalline with a d-spacing of 2.47Å corresponding to the (101) plane. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the presence of Ni ions inside the ZnO matrix with 2+ valance state. Room temperature magnetic measurements exhibit the hysteresis loop with saturation magnetization (Ms) of 1.6–2.56 (emu/g) and coercive field (Hc) of 260Oe. Micro-Raman studies illustrate doping/disorder induced additional Raman modes at ∼547, 574cm−1 in addition to 437cm−1 peak of pure ZnO. Photoluminescence (PL) spectra and UV–vis absorption measurements demonstrate some modification in the band edge emission and absorption characteristics, respectively. PL spectra also show defect related strong visible emission, which is believed to play a significant role in the FM ordering. These observations highlight the effect of changing defect density on the observed ferromagnetic moment values for the as synthesized Zn1−xNixO NPs. Magnetic interaction is quantitatively analyzed and explained using a bound magnetic polaron model and expected to arise from the intrinsic exchange interaction of Ni ions and OV, Zni defects. Systemic studies on the structural, magnetic, and optical properties reveal that both the nature of the defects as well as Ni2+ ions are significant ingredients behind attaining high moment as well as high ordering temperature in Ni doped ZnO NPs.
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•Fibrillar structure of pure PANI and PANI doped with sulphonic acids (SA) are synthesized by interfacial polymerization.•A comparative study on the structural, morphological and ...dielectric properties of undoped and doped PANI are studied.•The charge transport properties are studied based on the dielectric and AC conductivity.•The charge transport mechanisms in the composites are discussed.
Present work is primarily emphasized on the study of dielectric properties of sulphonic acids (SA) incorporated polyaniline (PANI). SA's function as dopants as well as surfactants for PANI. The PANI and PANI-SA samples are prepared by interfacial technique. The three composites prepared with three SA's (camphor sulphonic acid (CSA), dodecylbenzene sulphonic acid (DBSA) and polystyrene sulfonic acid (PSSA)) are characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), field effect scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA) and differential thermogram (DTG) prior to dielectric studies. The results of PANI not incorporated with SA are also shown for comparison. XRD shows enhancement of crystallinity on SA doping. FTIR confirms the molecular structure with enhanced oxidation states on SA doping. FESEM shows fibrillar morphology with reduced fiber diameter from 86 nm in pure PANI to minimum of 50 nm in one of the composites. TGA and DTG results show better thermal stability on SA doping. The dielectric and AC conductivity measurements of the undoped and dopedPANI are studied inthe frequency range of 42 kHz - 2 MHz and in the temperature range of 300 K–330 K. The dielectric constant for all the PANI composites increases with increase in temperature which indicates increase in mobility of the electric dipoles in the polymers. The dielectric constant for DBSA doped PANI is nearly 5000 which is much higher in context to interfacially polymerized nanofibres compared to that of undoped PANI where this value is about 800. Electric modulus studies show relaxation peaks in imaginary modulus spectra which ascertains about the type of relaxation process. The AC conductivity of the composites is found to be much higher than that of undoped PANI. The electrical conductivity increases with increase of temperature. This is suggested to be caused due to the activated trapped charge carriers.
Monodispersive silica nanoparticles have been synthesized via the Stöber process and further functionalized by adding fluorinated groups using fluoroalkylsilane in an ethanolic solution. In this ...process, six different sizes of fluorinated silica nanoparticles of varying diameter from 40 to 300 nm are prepared and used to deposit thin films on aluminum alloy surfaces using spin coating processes. The functionalization of silica nanoparticles by fluorinated group has been confirmed by the presence C–F bonds along with Si–O–Si bonds in the thin films as analyzed by Fourier transform infrared spectroscopy (FTIR). The surface roughnesses as well as the water contact angles of the fluorinated silica nanoparticle containing thin films are found to be increased with the increase of the diameter of the synthesized fluorinated silica nanoparticles. The thin films prepared using the fluorinated silica nanoparticles having a critical size of 119 ± 12 nm provide a surface roughness of ∼0.697 μm rendering the surfaces superhydrophobic with a water contact angle of 151 ± 4°. The roughness as well as the water contact angle increases on the superhydrophobic thin films with further increase in the size of the fluorinated silica nanoparticles in the films.
Various surface characterization techniques were used to study the modified surface chemistry of superhydrophobic aluminum alloy surfaces prepared by immersing the substrates in an aqueous solution ...containing sodium hydroxide and fluoroalkyl-silane (FAS-17) molecules. The creation of a rough micronanostructure on the treated surfaces was revealed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) and infrared reflection absorption spectroscopy (IRRAS) confirmed the presence of low surface energy functional groups of fluorinated carbon on the superhydrophobic surfaces. IRRAS also revealed the presence of a large number of OH groups on the hydrophilic surfaces. A possible bonding mechanism of the FAS-17 molecules with the aluminum alloy surfaces has been suggested based on the IRRAS and XPS studies. The resulting surfaces demonstrated water contact angles as high as ∼166° and contact angle hystereses as low as ∼4.5°. A correlation between the contact angle, rms roughnesses, and the chemical nature of the surface has been elucidated.
A four-element dual-band MIMO configuration consisting of split-ring resonator (SRR)-loaded inverted L-monopole antenna elements is realised. In the proposed antenna, the lower-frequency mode of the ...unloaded MIMO configuration merges with one SRR-induced antenna resonance. This leads to antenna operation around 2.93 GHz with wide impedance bandwidth (IBW) of 35.21%, encompassing the lower WLAN, worldwide interoperability for microwave access, wireless fidelity, fourth generation (4G)-long-term evolution and sub-6 GHz 5G bands. Furthermore, due to SRR loading, the proposed MIMO antenna exhibits a resonance at 5.68 GHz (IBW 6.86%), covering the upper WLAN band. Minimum inter-element isolation of 14 dB is achieved, in spite of the compact total area ($0.103\lambda _0^2 $0.103λ02, λ0 = highest operating wavelength) and the presence of inter-connected ground plane. Both the working bands exhibit directional radiation patterns with average gain $ \approx 4\, {\rm dBi}$≈4dBi. Experiments on the fabricated antenna prototype confirm that the simulated and measured S-parameters, radiation patterns (envelope-correlation coefficient, channel capacity loss and total active reflection coefficient) are in good agreement.
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