SB 268262

The effect of Sb-surfactant on GaInP CuPtB type ordering: assessment through dark field TEM and aberration corrected HAADF imaging.[Pubmed:28367549]

Phys Chem Chem Phys. 2017 Apr 12;19(15):9806-9810.

We report on the effect of Sb on the microstructure of GaInP layers grown by metal organic vapor phase epitaxy (MOVPE). These layers exhibit a CuPtB single variant ordering due to the intentional misorientation of the substrate (Ge(001) substrates with 6 degrees misorientation towards the nearest [111] axis). The use of Sb as a surfactant during the GaInP growth does not modify the type of ordering, but it is found that the order parameter (eta) decreases with increasing Sb flux. Dark field microscopy reveals a variation of the angle of the antiphase boundaries (APBs) with Sb amount. The microstructure is assessed through high angle annular dark field (HAADF) experiments and image simulation revealing Z-contrast loss in APBs due to the superposition of ordered domains.

Direct nucleation, morphology and compositional tuning of InAs1-x Sb x nanowires on InAs (111) B substrates.[Pubmed:28346221]

Nanotechnology. 2017 Apr 21;28(16):165601.

III-V ternary nanowires are interesting due to the possibility of modulating their physical and material properties by tuning their material composition. Amongst them InAs1-x Sb x nanowires are good candidates for applications such as Infrared detectors. However, this material has not been grown directly from substrates, in a large range of material compositions. Since the properties of ternaries are alterable by tuning their composition, it is beneficial to gain access to a wide range of composition tunability. Here we demonstrate direct nucleation and growth of InAs1-x Sb x nanowires from Au seed particles over a broad range of compositions (x = 0.08-0.75) for different diameters and surface densities by means of metalorganic vapor phase epitaxy. We investigate how the nucleation, morphology, solid phase Sb content, and growth rate of these nanowires depend on the particle dimensions, and on growth conditions such as the vapor phase composition, V/III ratio, and temperature. We show that the solid phase Sb content of the nanowires remains invariant towards changes of the In precursor flow. We also discuss that at relatively high In flows the growth mechanism alters from Au-seeded to what is referred to as semi In-seeded growth. This change enables growth of nanowires with a high solid phase Sb content of 0.75 that are not feasible via Au-seeded growth. Independent of the growth conditions and morphology, we report that the nanowire Sb content changes over their length, from lower Sb contents at the base, increasing to higher amounts towards the tip. We correlate the axial Sb content variations to the axial growth rate measured in situ. We also report spontaneous core-shell formation for Au-seeded nanowires, where the core is Sb-rich in comparison to the Sb-poor shell.

Differing Mechanisms of Death Induction by Fluorinated Taxane SB-T-12854 in Breast Cancer Cells.[Pubmed:28373418]

Anticancer Res. 2017 Apr;37(4):1581-1590.

BACKGROUND/AIM: Classical taxanes are routinely used in cancer therapy. In this study, mechanisms involved in death induction by the novel fluorine-containing taxane SB-T-12854 were investigated. MATERIALS AND METHODS: We employed breast cancer SK-BR-3, MCF-7 and T47D cell lines to assess activation of individual caspases, changes in the expression of proteins of the Bcl-2 family, and the release of pro-apoptotic factors from mitochondria into the cytosol after SB-T-12854 treatment. RESULTS: Caspase-2, -8, and -9 were activated in SK-BR-3 and MCF-7 cells. Only caspase-8 was activated in T47D cells. Caspase-7 and -6 were activated in all tested cells while caspase-3 was activated only in SK-BR-3 cells. Pro-apoptotic Bad protein seems to be important for cell death induction in all tested cells. Anti-apoptotic Bcl-2 and pro-apoptotic Bim, Bok, Bid and Bik seem to be also associated with cell death induction in some of the tested cells. The mitochondrial apoptotic pathway was significantly activated in association with the release of cytochrome c and Smac from mitochondria, but only in SK-BR-3 cells, not in MCF-7 and T47D cells. CONCLUSION: Cell death induced by SB-T-12854, in the tested breast cancer cells, differs regarding activation of caspases, changes in levels of pro-apoptotic and anti-apoptotic proteins of the Bcl-2 family and activation of the mitochondrial apoptotic pathway.

Critical evaluation of strategies for single and simultaneous determinations of As, Bi, Sb and Se by hydride generation inductively coupled plasma optical emission spectrometry.[Pubmed:28340714]

Talanta. 2017 May 15;167:217-226.

A systematic study of hydride generation (HG) of As, Bi, Sb and Se from solutions containing As(III), As(V), Bi(III), Sb(III), Sb(V), Se(IV) and Se(VI) was presented. Hydrides were generated in a gas-liquid phase separation system using a continuous flow vapor generation accessory (VGA) by mixing acidified aqueous sample, HCl and sodium borohydride reductant (NaBH4) solutions on-line. For detection, a simultaneous axially viewed inductively coupled plasma optical emission spectrometer (ICP-OES) was applied. Effects of the HCl concentration (related to sample and additional acid solutions) and type of the pre-reducing agents used for reduction of As(V), Sb(V) and Se(VI) into As(III), Sb(III) and Se(IV) on the analytical responses of As, Bi, Sb and Se were studied and discussed. Two compromised HG reaction conditions for simultaneous measurements of As+Bi+Sb (CC1) or As+Sb+Se (CC2) were established. It was found that choice of the pre-reductant prior to formation of the hydrides is critical in obtaining the dependable results of the analysis. Accordingly, for a As(III)+As(V)+Bi(III)+Sb(III)+Sb(V) mixture and using CC1, thiourea/thiourea-ascorbic acid interfered in Bi determination and hence, total As+Sb could be measured. If L-cysteine/L-cysteine-ascorbic acid were used, measurements of total Bi+Sb was possible in these HG reaction conditions. For a As(III)+As(V)+Sb(III)+Sb(V)+Se(IV)+Se(VI) mixture and using CC2, thiourea/thiourea-ascorbic acid and L-cysteine/L-cysteine-ascorbic acid influenced HG of Se but ensured total As+Sb determination. In contrast, heating a sample solution with HCl, although did not pre-reduce As(V) and Sb(V), assured quantitative reduction of Se(VI) to Se(IV). Finally, considering all favorable pre-reducing and HG conditions, methodologies for reliable determination of total As, Bi, Sb and Se by HG-ICP-OES were proposed. Strategies for single-, two- and three-element measurements were evaluated and validated, obtaining the detection limits (DLs) below 0.1ngg(-1) and precision typically in the range of 1.4-3.9% RSD.

Pharmacology of SB-273779, a nonpeptide calcitonin gene-related peptide 1 receptor antagonist.[Pubmed:11181905]

J Pharmacol Exp Ther. 2001 Mar;296(3):768-75.

Calcitonin gene-related peptide (CGRP), a potent vasodilatory and cardiotonic peptide, has a potential role for CGRP in diverse physiologic and pathophysiologic situations such as congestive heart failure, diabetes, migraine, and neurogenic inflammation. Although a peptide CGRP receptor antagonist, CGRP(8-37,) is available, its utility presents significant limitations for these indications. Here, we describe the properties of SB-(+)-273779 [N-methyl-N-(2-methylphenyl)-3-nitro-4-(2-thiazolylsulfinyl)nitrobenzanilide], a selective nonpeptide antagonist of CGRP(1) receptor. SB-(+)-273779 inhibited (125)I-labeled CGRP binding to SK-N-MC (human neuroblastoma cells) and human cloned CGRP(1) receptor with K(i) values of 310 +/- 40 and 250 +/-15 nM, respectively. SB-(+)-273779 also inhibited CGRP (3 nM)-activated adenylyl cyclase in these systems with IC(50) values of 390 +/-10 nM (in SK-N-MC) and 210 +/-16 nM (recombinant human CGRP receptors). Prolonged treatment (>30 min) of SK-N-MC cells with SB-(+)-273779 followed by extensive washing resulted in reduction in maximum CGRP-mediated adenylyl cyclase activity, suggesting that this compound has irreversible binding characteristics. In addition, SB-(+)-273779 antagonized CGRP-mediated 1) stimulation of intracellular Ca(2+) in recombinant CGRP receptors in HEK-293 cells, 2) inhibition of insulin-stimulated [(14)C]deoxyglucose uptake in L6 cells, 3) vasodilation in rat pulmonary artery, and 4) decrease in blood pressure in anesthetized rats. SB-(+)-273779 tested at 3 microM had no significant affinity for calcitonin, endothelin, angiotensin II, and alpha-adrenergic receptors under standard ligand binding assays. SB-(+)-273779 also did not inhibit forskolin and pituitary adenylate cyclase-activating polypeptide. These results suggest that SB-(+)-273779 is a valuable tool for studying CGRP-mediated functional responses in complex biological systems.