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91.
Layered double hydroxide (LDH) containing different metal constituents (Zn, Co, and Ni) was intercalated with different organic anions and has been used as fillers in low-density polyethylene (LDPE), and its thermal and flammability behavior was evaluated. The best thermal stability (∆T0.5 = 21 °C) was obtained with the LDPE-Ni/Al-dodecyl sulfate (4 wt %) nanocomposite. Addition of hydrophobic LDHs systematically decreases the enthalpy of melting and crystallization compared to the neat polymer. In LDPE-Co/Al-dodecyl sulfate (2 wt %) nanocomposite, the melting and crystallization enthalpies declined by about 45 J/g, indicating a good interaction of the filler with the polymer matrix. A reduction of 20% of the flammability for the LDPE-Ni/Al-stearate (4 wt %) nanocomposite was obtained. On the other hand, Zn–Co LDH as filler in LDPE nanocomposite did not affect effectively the same property. In an innovative study, results indicate that different metal constituents and interlayer anion of LDH as filler can change thermal and flammability properties of the polymer nanocomposite. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48737. 相似文献
92.
Florenza Lüder Ripoli Annika Mohr Susanne Conradine Hammer Saskia Willenbrock Marion Hewicker-Trautwein Silvia Hennecke Hugo Murua Escobar Ingo Nolte 《International journal of molecular sciences》2016,17(5)
Mammary neoplasms are the tumors most affecting female dogs and women. Formalin-fixed, paraffin-embedded (FFPE) tissues are an invaluable source of archived biological material. Fresh frozen (FF) tissue is considered ideal for gene expression analysis. However, strategies based on FFPE material offer several advantages. Branched-DNA assays permit a reliable and fast workflow when analyzing gene expression. The aim of this study was to assess the comparability of the branched-DNA assay when analyzing certain gene expression patterns between FF and FFPE samples in canine mammary tumors. RNA was isolated from 109 FFPE samples and from 93 FF samples of different canine mammary tissues. Sixteen (16) target genes (Tp53; Myc; HMGA1; Pik3ca; Mcl1; MAPK3; FOXO3; PTEN; GATA4; PFDN5; HMGB1; MAPK1; BRCA2; BRCA1; HMGA2; and Her2) were analyzed via branched-DNA assay (b-DNA). ACTB, GAPDH, and HPRT1 were used as data normalizers. Overall, the relative gene expression of the two different origins of samples showed an agreement of 63%. Still, care should be taken, as FFPE specimens showed lower expression of the analyzed targets when compared to FF samples. The fact that the gene expression in FFPE proved to be lower than in FF specimens is likely to have been caused by the effect of storage time. ACTB had the best performance as a data normalizer. 相似文献
93.
Silvia Gomez Joop A. Peters Jan C. van der Waal Wuzong Zhou Thomas Maschmeyer 《Catalysis Letters》2002,82(1-2):1-5
Platinum particles (<1.5 nm) have been shown to behave as bases in their interaction with -alumina. FTIR spectra of adsorbed pyridine probe molecules showed that the acid strength of the -alumina was decreased by the presence of (<1.5 nm) Pt particles. Ammonium chloride treatment converts the primary Pt clusters to H
x
Pt
y
Cl
z
intermediates that de-anchor from the support. Consequently, agglomeration to 8 nm Pt particles was observed following treatment in hydrogen at a relatively mild temperature. For the treated catalyst the IR data of absorbed pyridine show a 3 cm-1 increase relative to the original Pt/-Al2O3 catalyst, indicating a strengthening of the acidity. Changes in the Pt particle size were confirmed by FTIR spectroscopy of CO absorbed onto the Pt particles before and after treatment. Consecutive CO and pyridine probe adsorption demonstrated the electronic interplay between the Pt particles and the support. Pyridine adsorption onto the -alumina support of a Pt/Al2O3 catalyst pre-dosed with CO produces a nearly 40 cm-1 lowering of the CO peak position, indicative of CO bond weakening. In the case of CO adsorbed onto a catalyst pre-dosed with pyridine, a shift in the pyridine IR spectrum was only observed from the original highly dispersed catalyst. 相似文献
94.
Synthesis of Novel Niobium Aluminide-Based Composites 总被引:5,自引:0,他引:5
Daniel E. Garcia Silvia Schicker Jorn Bruhn Rolf Janssen Nils Claussen 《Journal of the American Ceramic Society》1997,80(9):2248-2252
A reactive sintering process has been used to produce almost fully dense composites with interpenetrating networks of NbAl3 and Al2 O3 . The process involves the reaction synthesis of niobium aluminides and Al2 O3 from compacts of intensively milled aluminum and Nb2 O5 powder mixtures. During carefully controlled heating under an inert atmosphere, the oxide reduction by aluminum to form niobium aluminides and Al2 O3 proceeds at temperatures below the melting point of aluminum. At temperatures of >1000°C, the reaction-formed niobium aluminides and Al2 O3 sinter. The present paper discusses processing parameters, such as attrition milling, the heating cycle, and the metal:ceramic ratio in the starting mixture, that control microstructure development and mechanical properties. 相似文献
95.
Cristhiane Caroline Ferrari Silvia Pimentel Marconi Germer José Maurício de Aguirre 《Drying Technology》2013,31(2):154-163
The purpose of this work was to study the effects of spray-drying conditions on the physicochemical characteristics of blackberry powder using a central composite rotatable design. Inlet air temperature (140–180°C) and maltodextrin concentration (5–25%) were employed as independent variables. Moisture content, hygroscopicity, anthocyanin retention, color, powder morphology, and particle size were analyzed. A higher inlet air temperature significantly increased the hygroscopicity of the powder, decreased its moisture content, and led to the formation of larger particles with smooth surfaces. Powders produced with higher maltodextrin concentrations were less hygroscopic, slightly lighter and less red, and had a lower moisture content. Anthocyanin retention was mainly affected by drying temperature due to the heat sensitivity of the pigment. The optimal processing conditions were an inlet air temperature of 140–150°C and maltodextrin concentration of 5–7%. Overall, these results indicate that good quality powders can be obtained by spray drying, with potential applications for the food industry. 相似文献
96.
Giuseppe Spoto Silvia Bordiga Domenica Scarano Adriano Zecchina 《Catalysis Letters》1992,13(1-2):39-44
In this note an exchange procedure of the acidic protons of H-ZSM5 by CuI ions through reaction with CuCl in the gas phase is described. In the so obtained CuI-ZSM5 exchanged zeolite the CuI ions are in well defined configuration and form with NO mono and di-nitrosyl complexes of high structural and spectroscopic quality. The CuI(NO)2 species are transformed at RT into CuII(NO)X (X=O– and/or NO
2
–
) species which could represent an intermediate in NO decomposition. 相似文献
97.
Silvia Carra Germano Gaudenzi Alessandra Dicitore Davide Saronni Maria Celeste Cantone Alice Plebani Anna Ghilardi Maria Orietta Borghi Leo J. Hofland Luca Persani Giovanni Vitale 《International journal of molecular sciences》2021,22(6)
Medullary thyroid carcinoma (MTC) is a tumor deriving from the thyroid C cells. Vandetanib (VAN) and cabozantinib (CAB) are two tyrosine kinase inhibitors targeting REarranged during Transfection (RET) and other kinase receptors and are approved for the treatment of advanced MTC. We aim to compare the in vitro and in vivo anti-tumor activity of VAN and CAB in MTC. The effects of VAN and CAB on viability, cell cycle, and apoptosis of TT and MZ-CRC-1 cells are evaluated in vitro using an MTT assay, DNA flow cytometry with propidium iodide, and Annexin V-FITC/propidium iodide staining, respectively. In vivo, the anti-angiogenic potential of VAN and CAB is evaluated in Tg(fli1a:EGFP)y1 transgenic fluorescent zebrafish embryos by analyzing the effects on the physiological development of the sub-intestinal vein plexus and the tumor-induced angiogenesis after TT and MZ-CRC-1 xenotransplantation. VAN and CAB exert comparable effects on TT and MZ-CRC-1 viability inhibition and cell cycle perturbation, and stimulated apoptosis with a prominent effect by VAN in MZ-CRC-1 and CAB in TT cells. Regarding zebrafish, both drugs inhibit angiogenesis in a dose-dependent manner, in particular CAB shows a more potent anti-angiogenic activity than VAN. To conclude, although VAN and CAB show comparable antiproliferative effects in MTC, the anti-angiogenic activity of CAB appears to be more relevant. 相似文献
98.
Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands 下载免费PDF全文
Dr. Silvia Pace Dr. Giandomenico Brogin Dr. Maria Antonietta Stasi Dr. Teresa Riccioni Franco Borsini Dr. Francesca Capocasa Dr. Francesco Manera Carlo Tallarico Dr. Pietro Grossi Dr. Federica Vacondio Dr. Michele Bassi Dr. Francesca Bartoccini Dr. Simone Lucarini Dr. Giovanni Piersanti Prof. Giorgio Tarzia Walter Cabri Dr. Patrizia Minetti 《ChemMedChem》2015,10(7):1149-1152
Inhibition of adenosine A2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A2AR (Ki=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours). 相似文献
99.
Yikai Chen Yang Tan Silvia Tessarini Sanjay Sampath 《Journal of Thermal Spray Technology》2013,22(2-3):110-115
Spray parameters play an important role on the microstructure and properties of plasma-sprayed coatings. Parameters such as spray distance, plasma gas flow and current, raster speed, and spray angle all can be varied. In this paper, an integrated study to investigate the effects and influences of spray angle on properties of yttria-stabilized zirconia coatings was carried out with spray angles of 60°, 75°, and 90° (to the substrate surface). In situ coating property sensor based on beam curvature measurements was used to measure the evolving stress and elastic moduli of the resultant coatings and combined with other characterization tools for thermo-physical property and microstructure analysis, such as laser flash and scanning electron microscopy. The results indicate that the coating with 60° spray angle had the lowest thermal conductivity and more compliant structure. This study seeks to understand the mechanism for this effect and will provide important insight into parametric sensitivities on complex spray parts. 相似文献
100.
Andrea Brenna Silvia Beretta Riccardo Uglietti Luciano Lazzari MariaPia Pedeferri Marco Ormellese 《腐蚀工程科学与技术》2017,52(4):253-260
The criterion used to verify the cathodic protection condition of a structure is based on structure-to-electrolyte potential measurement, which can include an ohmic drop contribution. Among the available techniques, the use of potential probes with internal reference electrode and of corrosion coupons with a so-called soil-access tube represents the most appropriate way to measure the IR-free potential, eliminating the ohmic drop contribution. An alternative is represented by on-off technique if equalising, galvanic or stray currents are not present. Laboratory tests have been carried out in soil-simulating solution on cathodically protected carbon steel in order to evaluate the effectiveness of off-potential for the assessment of cathodic protection. Instant-off potential is not reliable in overprotection condition; moreover, the accuracy of the measurement is strongly influenced by the presence of external current as galvanic or equalising currents. The effect of low-pass filter in the data acquisition system on the potential reading is discussed. 相似文献