An extensive radiative transfer analysis of circumstellar SiO ‘thermal’ radio line emission from a large sample of M-type AGB stars has been performed. The sample contains 18 irregulars of type Lb (IRV), 7 and 34 semiregulars of type SRa and SRb (SRV), respectively, and 12 Miras. New observational material, which contains data in several SiO rotational lines in the ground vibrational state, is ...

In this study, we synthesized three analogous bent-core molecules, a hydrogen-bonded complex and a covalent-bonded compound with branched siloxane units (H-SiO and C-SiO, respectively) and a hydrogen-bonded complex with an alkyl unit (H-Alk), and investigated the effects of the hydrogen bonding and branched siloxane terminal units on their mesomorphic properties. The covalent-bonded compound C-...

OBJECTIVE To determine the feasibility of labeling human mesenchymal stem cells (hMSCs) with bifunctional nanoparticles and assessing their potential as imaging probes in the monitoring of hMSC transplantation. MATERIALS AND METHODS The T1 and T2 relaxivities of the nanoparticles (MNP@SiO(2)[RITC]-PEG) were measured at 1.5T and 3T magnetic resonance scanner. Using hMSCs and the nanoparticles,...

Context. Methanol masers are often found in linear distributions, and it has been hypothesized that these masers are tracing circumstellar accretion disks around young massive stars. However, recent observations in H2 emission have shown what appear to be outflows at similar angles to the maser distribution angles, not perpendicular as expected in the maser-disk scenario. Aims. The main motivat...

MgCl(2)-SiO(2)/TiCl(4) Ziegler-Natta catalysts for ethylene polymerization were prepared by impregnation of MgCl(2) on SiO(2) in heptane and further treatment with TiCl(4). MgCl(2)·nEtOH adduct solutions were prepared with various EtOH/MgCl(2) molar ratios for preparation of the MgCl(2)-supported and MgCl(2)-SiO(2)-supported catalysts in order to investigate the effect on polymerization perform...

this article contains the views of different scholars and their researches about allah verdi khan bridge. in this brief study two important points have been highlighted. first, who is the probable constructor of the bridge and what the references tell about it. secondly, the explanation about the grave mistakes of the foundation and completion dates of the bridge and thus argument about the exa...

Some peptide-based drugs, including oxytocin, vasopressin, ziconotide, pramlintide, nesiritide, and octreotide, contain one intramolecular disulfide bond. A novel and reusable monodispersed silica nanosphere-supported Pt(IV) complex (SiO₂@TPEA@Pt(IV)); TPEA: N-[3-(trimethoxysilyl)propyl]ethylenediamine) was synthesized via a four-step procedure and was used for the formation of intramolecular d...

BACKGROUND Silica (SiO₂) nanoparticles (NPs) are widely used in diverse industrial and biomedical applications. Their applicability depends on surface modifications, which can limit potential health problems. OBJECTIVE To assess the potential impact of SiO₂ NP exposure and NPs chemical modifications in allergic airway inflammation. METHODS Mice were sensitized by five repetitive intraperito...

Mesoporous and nonporous SiO(2) and Al(2)O(3) adsorbents were reacted with the fluoroquinolone carboxylic acid ofloxacin over a range of pH values (2-10) and initial concentrations (0.03-8 mM) to investigate the effects of adsorbent type and intraparticle mesopores on adsorption/desorption. Maximum ofloxacin adsorption to SiO(2) surfaces occurs slightly below the pK(a2) (pH 8.28) of the antibio...

the present study aimed to use a method for the synthesis of some 3, 4-dihydropyrimidin-2-(1h) - ones/thiones. the study tried to answer the question whether this reaction can be performed without solvent and with new catalyst or not. to find answer to the question, we described a novel protocol for the efficient synthesis of 3, 4-dihydropyrimidin-2-(1h)-one derivatives using aromatic aldehyde,...