Ureidosulfocoumarin Derivatives As Selective and Potent Carbonic Anhydrase IX and XII Inhibitors

Owing to severe allergic reactions (anaphylaxis) and resistance exhibited by sulfonamide-based carbonic anhydrase (CA) inhibitors, non-classical or non-sulfonamide CA inhibitors are gaining increased attention by medicinal chemists. In this context, we report the design and synthesis of 30 new non-sulfonamide sulfocoumarin derivatives as CA inhibitors. They were investigated against hCA I and II (cytosolic isozymes) as well as hCA IX and XII (transmembrane, tumor-associated enzymes). All compounds showed prominent selectivity for the tumor-associated isoenzymes hCA IX and XII over the cytosolic isoenzymes hCA I and II. Among all synthesized compounds, 1-(2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)-3-(o-tolyl)urea( 5 j )and1-(3-fluorophenyl)-3-(8-methoxy-2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)urea( 5 q )were found to be more potent and to have better inhibition constant values against hCA IX than the standard acetazolamide (AAZ), with K_i values of 23.6 and 23.3 nM, respectively. All other compounds were found to be active under K_i=920 nM against hCA IX and XII.This study provides a new perspective for the future development of non-sulfonamide derivatives as selective CA inhibitors.     

Fabrication of an a-IGZO thin film transistor using selective deposition of cobalt by the self-assembly monolayer (SAM) process

Interest in transparent oxide thin film transistors utilizing ZnO material has been on the rise for many years. Recently, however, IGZO has begun to draw more attention due to its higher stability and superior electric field mobility when compared to ZnO. In this work, we address an improved method for patterning an a-IGZO film using the SAM process, which employs a cost-efficient micro-contact printing method instead of the conventional lithography process. After a-IGZO film deposition on the surface of a SiO2-layered Si wafer, the wafer was illuminated with UV light; sources and drains were then patterned using n-octadecyltrichlorosilane (OTS) molecules by a printing method. Due to the low surface energy of OTS, cobalt was selectively deposited on the OTS-free a-IGZO surface. The selective deposition of cobalt electrodes was successful, as confirmed by an optical microscope. The a-IZGO TFT fabricated using the SAM process exhibited good transistor performance: electric field mobility (micro(FE)), threshold voltage (V(th)), subthreshold slope (SS) and on/off ratio were 2.1 cm2/Vs, 2.4 V, 0.35 V/dec and 2.9 x 10(6), respectively.     

Synthesis of multi-walled carbon nanotube/polyhedral oligomeric silsesquioxane nanohybrid by utilizing click chemistry

A new hybrid material consisting of a polyhedral oligomeric silsesquioxane (POSS) and carbon nanotube (CNT) was synthesized by a simple and versatile approach entailing click coupling between azide moiety-functionalized POSS and alkyne-functionalized multi-walled CNTs. This approach provides a simple and convenient route to efficiently functionalize a wide variety of nanoscale nanostructure materials on the surface of CNTs.     

Influence of High Amplitude Mould Vibration on the Morphology of Silicon in the Al-Si Alloy (A308)

Silicon - Today’s casting industries strive to produce high-quality cast components in an efficient, cost-effective, eco-friendly, and sustainable way. To achieve this, with an indigenously...     

Intrinsic and Interdiffusion in Cu-Sn System

Solid-solid diffusion couples assembled with disks of copper, tin and intermetallics (Cu₃Sn and Cu₆Sn₅) were employed to investigate the Kirkendall effect in the copper-tin system at the temperature of 200 °C. In the Cu(99.9%)/Sn diffusion couple, inert alumina particles used as markers were identified in the Cu₆Sn₅ phase, while microvoids were observed at the Cu/Cu₃Sn interface. The Cu(99.9%)/Sn and Cu(99.9%)/Cu₆Sn₅ diffusion couples annealed at 200 °C for 10 days were analyzed for intrinsic diffusion coefficients of Cu and Sn in the Cu₆Sn₅ and Cu₃Sn phases, respectively with due consideration of changes in molar volume. Interdiffusion, integrated and effective interdiffusion coefficients were also calculated for the intermetallic phases. Diffusion couples annealed at 125-400 °C for various times were analyzed for the kinetic parameters such as growth rate constants and activation energies for the formation of Cu₃Sn and Cu₆Sn₅ phases. Uncertainties in the calculated intrinsic diffusivities of Cu and Sn arise mainly from the non-planar morphologies of the interfaces and the non-planar distribution of the markers. Intrinsic diffusion coefficients based on average locations of the marker plane indicate that Cu is the faster diffusing component than Sn in both the Cu₃Sn and Cu₆Sn₅ phases.     

In vitro biological and tribological properties of transparent magnesium aluminate (Spinel) and aluminum oxynitride (ALON<Superscript>®</Superscript>)

The purpose of this first generation investigation is to evaluate the in vitro cytotoxicity, cell-materials interactions and tribological performance of Spinel and ALON^® transparent ceramics for potential wear resistant load bearing implant applications. Besides their non-toxicity, the high surface energy of these ceramics significantly enhanced in vitro cell-materials interactions compared to bioinert commercially pure Ti as control. These transparent ceramics with high hardness in the range of 1334 and 1543 HV showed in vitro wear rate of the order of 10^?6 mm³ Nm^?1 against Al₂O₃ ball at a normal load of 20 N.     

Wafer-scale self-assembled plasmonic thin films

Plasmonic films have become important for many applications including photonics, energy conversion, and chemical sensing, but the fabrication of these films often requires special equipment, great care, and skill. Colloidal metal nanoparticles offer an alternative as they have been shown to self-assemble into highly-ordered monolayer films by the simple and inexpensive technique of drop casting. Using this technique, we fabricated wafer-scale films of highly-ordered 6 nm Au nanoparticles and evaluated them as candidates for plasmonic applications. These colloidal films were found to support uniform and high-quality plasmon modes over the entire area of the wafer. A combination of microscopy and spectroscopy was used to evaluate and correlate the structural and optical qualities of the films. Electron and atomic force microscopy showed that the nanoscale structure of the films was compact and highly ordered, with few defects or bilayers. Spectroscopic ellipsometry showed that the majority of the film was optically quite uniform with some bilayer patches and voids. These were subsequently confirmed by microscopy. Optical analysis of the thin film showed a prominent plasmon resonance band across the entire wafer. The plasmon frequency was quite insensitive to the presence of voids or bilayers. The width of the plasmon band was more sensitive to bilayers, however, and was found to be as much as 15% wider than in monolayer regions. These results indicate that self-assembled colloidal thin films should be suitable for large-scale plasmonic applications.     

Probing Site Symmetry Around Eu3+ in Nanocrystalline ThO2 Using Time Resolved Emission Spectroscopy

ThO₂:Eu³⁺ nanoparticles were synthesized at 300°C by combustion route using urea as a fuel and characterized by thermogravimetric/differential thermal analysis, X‐ray diffraction, transmission electron microscopy, and photoluminescence techniques. To investigate the effect of annealing temperature, as synthesized powder were heated further at 500°C, 700°C, and 900°C. It was observed that extent of asymmetry around Eu³⁺ at 700°C/900°C is very high as compared to as‐prepared or 500°C annealed sample. Based on the time resolved emission spectroscopic investigations, it was inferred that two different types of Eu³⁺ ions were present in the ThO₂ nanoparticles. In ThO₂ structure, Eu³⁺ ions occupy two sites; cubic (O_h) and noncubic (<C_2v) as can be confirmed from our emission studies. Short‐lived species T₁ (~1.3–3.4 ms) predominates at higher annealing temperature arises because of Eu³⁺ ions occupying noncubic (<C_2v) sites without inversion symmetry, whereas long‐lived species T₂ (~4.6–6.6 ms) can be ascribed to Eu³⁺ ions occupying cubic sites (O_h) with inversion symmetry.     

Fabrication and characterization of in situ synthesized iron oxide‐modified polyimide nanoweb by needleless electrospinning

A series of poly(amic acid) (PAA) solutions were prepared by sol–gel condensation of 4,4′‐oxydianiline (ODA) and 4,4′‐oxydiphthalic anhydride (ODPA), containing various wt % (5, 10, 15) of an iron oxide precursor, that is, tris(acetylacetonato)iron(III) complex. The resulting PAA solutions were electrospun at 78 kV and collected as webs of nonwoven nanofibers of diameter ～60–70 nm and subsequently converted to iron oxide‐modified polyimide (PI) nanofibers by slow thermal imidization. Aminopropyl triethoxysilane (APTES) and tetraethoxyorthosilicate (TEOS) were used as coupling agent and silica precursor, respectively, to enhance the compatibility between organic polymer matrix and inorganic moieties. SEM images reveal smooth and defect‐free surface morphologies of the nanofibers. Superparamagnetic properties of the nanofibers were revealed by vibrating sample magnetometer (VSM). FT‐infrared spectroscopy (IR), powder XRD, thermogravimetric analysis, and differential scanning calorimetry were employed to systematically characterize material structural properties, thermal stabilities, etc. Nanowebs showed excellent thermal stability around 446°C, with a glass transition temperature around 270°C. The above study demonstrates a good example for fabrication of highly thermally stable bead‐free nanofiber webs by needleless electrospinning. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40432.     

Photovoltaics literature survey (No. 110)

In order to help keep readers up‐to‐date in the field each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including IEEE Transactions on Electron Devices, Journal of Applied Physics, Applied Physics Letters, Progress in Photovoltaics and Solar Energy Materials and Solar Cells. To assist the reader, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Santosh Shrestha at s.shrestha@unsw.edu.au .