Mechanical behavior and correlation between dynamic fragility and dynamic mechanical properties of curaua fiber composites

In this study, the mechanical properties and physical–chemical characteristics of curaua composites were evaluated using tensile and short beam testing and dynamic mechanical analysis. Curaua/polyester composites with different pretreatment (washing and drying), fiber length (10–50 mm) and fiber volume fraction (%V_f) (11, 22, and 38 vol%) were studied. The results show that the composites produced using 50 mm long washed/dried fibers and %V_f of 38 vol% achieved better mechanical properties, such as tensile strength and modulus and short beam strength. Fragility index “m” of the composites increased upon curaua incorporation, which may be attributed to a reduction in polyester chemical interactions (due to fiber dwelling of the polyester network). The energy required in initiating the cooperative motion at the “ideal” glass transition temperature and the cooperative rearrangement regions (CRR) also increased upon curaua incorporation, since CRR is considered the subsystem of the sample and for higher fiber content the greater the molecular heterogeneity. Finally, the Angell fragility concept was successfully applied to polymer composite systems. POLYM. COMPOS., 35:1078–1086, 2014. © 2013 Society of Plastics Engineers     

tert‐Butylcarbamate‐Containing Histone Deacetylase Inhibitors: Apoptosis Induction,Cytodifferentiation, and Antiproliferative Activities in Cancer Cells

Herein we report novel pyrrole‐ and benzene‐based hydroxamates ( 8 , 10 ) and 2′‐aminoanilides ( 9 , 11 ) bearing the tert‐butylcarbamate group at the CAP moiety as histone deacetylase (HDAC) inhibitors. Compounds 8 b and 10 c selectively inhibited HDAC6 at the nanomolar level, whereas the other hydroxamates effected an increase in acetyl‐α‐tubulin levels in human acute myeloid leukemia U937 cells. In the same cell line, compounds 8 b and 10 c elicited 18.4 and 21.4 % apoptosis, respectively (SAHA: 16.9 %), and the pyrrole anilide 9 c displayed the highest cytodifferentiating effect (90.9 %). In tests against a wide range of various cancer cell lines to determine its antiproliferative effects, compound 10 c exhibited growth inhibition from sub‐micromolar (neuroblastoma LAN‐5 and SH‐SY5Y cells, chronic myeloid leukemia K562 cells) to low‐micromolar (lung H1299 and A549, colon HCT116 and HT29 cancer cells) concentrations. In HT29 cells, 10 c increased histone H3 acetylation, and decreased the colony‐forming potential of the cancer cells by up to 60 %.     

Tracer Dispersion in Stirred Tank Reactors: Asymptotic Properties and Mixing Characterization

This article addresses the characterization of dispersion and homogenization phenomena in stirred vessels through the analysis of dispersion curves that can be obtained experimentally by means of conductivity measurements. New insights on mixing conditions can be achieved from the analysis of the qualitative and asymptotic properties of tracer dispersion curves. The results obtained are interpreted in the context of the spectral approach to the advection‐diffusion equation. It is shown that any flow model aimed at reproducing the experimentally determined dispersion curves must be at least two‐dimensional. Convection‐enhanced dispersion associated with the spectral structure of the advection‐diffusion equation is addressed.     

Mn/Mg/Al-spinels as catalysts for SOx abatement: Influence of CeO2 incorporation and catalytic stability

Mg,Mn,Al-oxides with spinel structure, Al/(M²⁺ + Al) molar ratio of 0.25 and 0.50 and an Mn/Mg molar ratio of 0.30 have been evaluated as catalysts for SO_x removal under conditions similar to those found in FCC units. The best performance was that of the sample with the higher aluminium content. The incorporation of CeO₂ in this sample favored SO_x uptake for short reaction times as well as the reduction of the sulfated catalysts. When the regeneration was started at 530 °C, only H₂S was observed as reaction product, but when this step started at 650 °C, the release of SO₂ preceded that of H₂S, regardless of the chemical composition of the sample. As to the additive performance for successive reaction–regeneration cycles, the incorporation of CeO₂ produced a less efficient catalyst with regard to the removal of the SO₂ along the process, but with a higher regeneration efficiency and a lower formation of SO₂ as regeneration product.     

Annealing and crystallization kinetics of poly(lactic acid) pieces obtained by additive manufacturing

In this study, we investigated the influence of isothermal treatment of poly(lactic acid) (PLA) 3D printed samples at different crystallization temperatures. In this case, we analyzed the effect of each crystallization temperature on spherulites formation in printed PLA, affecting the final mechanical properties of pieces. For such, the thermomechanical properties, morphological structure, and crystallization kinetics were analyzed before and after thermal treatment. The 3D printed samples were heat treated at 80°C, 90°C, 100°C, 110°C, and 119°C. With annealing, we observed an improvement in the mechanical PLA properties; however, the exothermic crystallization peak was different for the samples. Pieces before annealing were found to have a low crystallinity index (Ic) of 2%–7%, and the pieces after annealing presented a considerable Ic (27%–34%). Annealing temperatures of 100°C, 110°C, and 119°C produced the fastest crystallization kinetics, while annealing temperatures of 80°C and 90°C resulted in the lowest crystallization kinetics for complete crystallization. After annealing, improvement in the flexural strength (34%–47%) and Young's modulus (26%–51%) for all annealed pieces occurred. The appropriate condition was observed at 100°C, which was the onset temperature of crystallization, owing to the combination of the shorter time of crystallization with the increased mechanical properties.     

Preparation,characterization, and antimicrobial activity of ferrocene-containing polymeric materials

Ferrocenyl(benzyl) imidazole (FcIm) and two related methyl-imidazolium salts (FcMIm⁺I^– and FcMIm⁺PF₆^–) were synthesized for their incorporation into plasticized PVC by solvent casting technique. The obtained materials were investigated for their thermal stability and, compared to pure polymer, films containing ionic ferrocene derivatives in 0.5% w/w loading were found slightly more stable. The pure ferrocene compounds showed antibacterial activity against Staphylococcus epidermis, but not against Escherichia coli, with a maximum for FcMIm⁺PF₆^– salt. After incorporation into PVC polymer, antibacterial activity against S. epidermis was observed (by disk diffusion test) only for PVC/FcMIm⁺PF₆^– (5% w/w) film, from which a release of 14.6% of the ferrocenilimidazolium cation in aqueous medium was measured after 24 hr.     

Trajectories of resilience, resistance, and distress during ongoing terrorism: The case of Jews and Arabs in Israel.

This is the 1st longitudinal examination of trajectories of resilience and resistance (rather than ill-being) among a national sample under ongoing threat of mass casualty. The authors interviewed a nationally representative sample of Jews and Arabs in Israel (N = 709) at 2 times during a period of terrorist and rocket attacks (2004?2005). The resistance trajectory, exhibiting few or no symptoms of traumatic stress and depression at both time points, was substantially less common (22.1%) than has previously been documented in studies following single mass casualty events. The resilience trajectory, exhibiting initial symptoms and becoming relatively nonsymptomatic, was evidenced by 13.5% of interviewees. The chronic distress trajectory was documented among a majority of participants (54.0%), and a small proportion of persons were initially relatively symptom-free but became distressed (termed delayed distress trajectory; 10.3%). Less psychosocial resource loss and majority status (Jewish) were the most consistent predictors of resistance and resilience trajectories, followed by greater socioeconomic status, greater support from friends, and less report of posttraumatic growth. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure and morphology of solution blended poly(vinylidene fluoride)/montmorillonite nanocomposites

Nanocomposites based on poly(vinylidene fluoride) were prepared with montmorillonite by solution blending. The samples were characterized by small angle X‐ray scattering, wide angle X‐ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Different crystallization conditions, that is, evaporation of the solvent and coprecipitation with two different antisolvents, H₂O or supercritical CO₂ (scCO₂), were tested and their influence on the resulting structure and morphology of the samples were studied. Coprecipitation with scCO₂ induced an ordinate crystalline framework and an intercalated morphology of clay, with a consequent large improvement in modulus. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Microsatellite Instability: From the Implementation of the Detection to a Prognostic and Predictive Role in Cancers

Microsatellite instability (MSI) has been identified in several tumors arising from either germline or somatic aberration. The presence of MSI in cancer predicts the sensitivity to immune checkpoint inhibitors (ICIs), particularly PD1/PD-L1 inhibitors. To date, the predictive role of MSI is currently used in the selection of colorectal cancer patients for immunotherapy; moreover, the expansion of clinical trials into other cancer types may elucidate the predictive value of MSI for non-colorectal tumors. In clinical practice, several assays are used for MSI testing, including immunohistochemistry (IHC), polymerase chain reaction (PCR) and next-generation sequencing (NGS). In this review, we provide an overview of MSI in various cancer types, highlighting its potential predictive/prognostic role and the clinical trials performed. Finally, we focus on the comparison data between the different assays used to detect MSI in clinical practice.     

What Are the Biomarkers for Immunotherapy in SCLC?

Small-cell lung cancer (SCLC) is an aggressive malignancy that exhibits a rapid doubling time, a high growth fraction, and the early development of widespread metastases. The addition of immune checkpoint inhibitors to first-line chemotherapy represents the first significant improvement of systemic therapy in several decades. However, in contrast to its effects on non-SCLC, the advantageous effects of immunotherapy addition are modest in SCLC. In particular, only a small number of SCLC patients benefit from immune checkpoint inhibitors. Additionally, biomarkers selection is lacking for SCLC, with clinical trials largely focusing on unselected populations. Here, we review the data concerning the major biomarkers for immunotherapy, namely, programmed death ligand 1 expression and tumour mutational burden. Furthermore, we explore other potential biomarkers, including the role of the immune microenvironment in SCLC, the role of genetic alterations, and the potential links between neurological paraneoplastic syndromes, serum anti-neuronal nuclear antibodies, and outcomes in SCLC patients treated with immunotherapy.