Contact effects in organic thin-film transistor sensors

Contact effects in organic thin-film transistors (OTFTs) sensors are here investigated specifically respect to the gate field-induced sensitivity enhancement of more than three orders of magnitude seen in a DHα6T OTFT sensor exposed to 1-butanol vapors. This study shows that such a sensitivity enhancement effect is largely ascribable to changes occurring to the transistor channel resistance. Effects, such as the changes in contact resistance, are seen to influence the low gate voltage regime where the sensitivity is much lower.     

Densification of Oxide Nanoparticle Thin Films by Irradiation with Visible Light

A technique is presented that allows for altering of the physical characteristics of films of TiO₂ nanoparticles by exposure to visible light. In this technique, dye‐sensitized oxide nanoparticles are deposited on a substrate by dip‐coating. Photodissociation of the organic ligand layer leads to cross‐linking of the nanoparticles. Consequently, irradiated films have a decreased porosity, an increased index of refraction and an increased hydrophobicity. Films irradiated with green light are compared to films irradiated with UV light. Within experimental error, visible‐ and UV‐illumination induces the same changes in the films. The mechanism of surfactant elimination in dye‐sensitized oxide particles is discussed, patterning is demonstrated, and prospective applications of the technique are considered.     

Occurrence of urolithins,gut microbiota ellagic acid metabolites and proliferation markers expression response in the human prostate gland upon consumption of walnuts and pomegranate juice

Epidemiology supports the important role of nutrition in prostate cancer (PCa) prevention. Pomegranate juice (PJ) exerts protective effects against PCa, mainly attributed to PJ ellagitannins (ETs). Our aim was to assess whether ETs or their metabolites ellagic acid and urolithins reach the human prostate upon consumption of ET‐rich foods and to evaluate the effect on the expression of three proliferation biomarkers. Sixty‐three patients with BPH or PCa were divided into controls and consumers of walnuts (35 g walnuts/day) or pomegranate (200 mL PJ/day) for 3 days before surgery. Independently of the ETs source, the main metabolite detected was urolithin A glucuronide, (3,8‐dihydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) (up to 2 ng/g) together with the traces of urolithin B glucuronide, (3‐hydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) and dimethyl ellagic acid. The small number of prostates containing metabolites was likely caused by clearance of the compounds during the fasting. This was corroborated in a parallel rat study and thus the presence of higher quantities of metabolites at earlier time points cannot be discarded. No apparent changes in the expression of CDKN1A, MKi‐67 or c‐Myc were found after consumption of the walnuts or PJ. Our results suggest that urolithin glucuronides and dimethyl ellagic acid may be the molecules responsible for the beneficial effects of PJ against PCa.     

Hydraulic/partitioning tracer tomography for DNAPL source zone characterization: small-scale sandbox experiments

Dense nonaqueous phase liquids (DNAPL) are prevalent at a large number of sites throughout the world. The variable release history, unstable flow, and geologic heterogeneity make the spatial distribution of DNAPLs complex. This causes difficulties in site remediation contributing to long-term groundwater contamination for decades to centuries. We present laboratory experiments to demonstrate the efficacy of Sequential Successive Linear Estimator (SSLE) algorithm that images DNAPL source zones. The algorithm relies on the fusion of hydraulic and partitioning tracer tomography (HPTT) to derive the best estimate of the K heterogeneity, DNAPL saturation (S(N)) distribution, and their uncertainty. The approach is nondestructive and can be applied repeatedly. Results from our laboratory experiments show that S(N) distributions compare favorably with DNAPL distributions observed in the sandbox but not so with local saturation estimates from core samples. We also found that the delineation of K heterogeneity can have a large impact on computed S(N) distributions emphasizing the importance of accurate delineation of hydraulic heterogeneity.     

Aggregation of Alcohols Ethoxylates in n-Heptane

The solubility and aggregation process of polyethoxylated non-ionic surfactants, of general formula C _i H_2i+1–(O–CH₂–CH₂) _j –OH with i = 6, 8, 10 and j = 3–6 (C _i EO _j ), in heptane were studied. The aggregation of C _i EO _j surfactants in heptane was investigated by using methylene blue (MB) as an absorption probe. In solutions of MB in the presence of these surfactants in heptane, at concentrations larger than the re-dissolution concentration, the UV bands associated to free MB (A ₁) and MB–EO complex (A ₂) were detected. The ratio of these intensities A ₂/A ₁, was used to study the kinetics of the complex formation in pure surfactant. The value of A ₂/A ₁ depends on the surfactant structure and the media wherein MB is dissolved, being larger in the pure surfactant than in heptane solutions. These results are explained in terms of solvent effect and aggregate structures on the complex formation.

Preparation,alumina-pillaring and oxidation catalytic performances of synthetic Ni-saponite

Synthetic saponite containing Ni²⁺ as octahedral cations has been prepared by a simple hydrothermal procedure, and has been intercalated with Al₁₃-polycations. The catalytic performance of the pillared solids in the epoxidation of (Z)-cyclooctene and the oxidation of cyclohexanone in the presence of benzonitrile, Baeyer–Villiger reaction, using hydrogen peroxide (70%) as a clean oxidant have been studied. For comparison, Mg-saponite was synthesized under the same conditions and tested for the same reaction.     

Synthesis,characterization and compared reactivity of asymmetrical ansa-metallocenes

Rac and meso ansa-zirconocenes [Zr{1-Me₂Si(3-R-(η⁵-C₉H₅))(3-R′-(η⁵-C₉H₅))}Cl₂] (R = Et, R′ = H; R = Pr, R′ = H; and R = Et, R′ = Pr) 4–9 have been prepared by the reaction of ZrCl₄ with the corresponding dilithiated derivatives from the ligands {1-Me₂Si(3-R-(η⁵-C₉H₅))(3-R′-(η⁵-C₉H₅))} (R = Et, R′ = H 1; R = Pr, R′ = H 2; and R = Et, R′ = Pr 3) in diethyl ether/toluene at ?78 °C. The molecular structure of rac [Zr{1-Me₂Si(3-Et-(η⁵-C₉H₅))(3-Pr-(η⁵-C₉H₅))}Cl₂] 8 has been determined by single crystal X-ray diffraction studies, which show a pseudotetrahedral environment formed by the two chlorine ligands and two η⁵-coordinated indenyl ligands. The activity in homogeneous and heterogeneous polymerization is compared and discussed.     

Modification with Organometallic Compounds Improves Crossing of the Blood–Brain Barrier of [Leu5]‐Enkephalin Derivatives in an In Vitro Model System

Enkephalin peptides are thought to be suitable vectors for the passage of the blood–brain barrier (BBB). Modifications that do not alter the amino acid sequence are often used to improve the permeation through living membrane systems. As a new type of modification we introduce organometallic compounds, in particular ferrocene carboxylic acid. Derivatives of [Leu⁵]enkephalin were synthesised and labelled with organometallic compounds by using solid‐phase synthesis techniques. All new metal–peptide bioconjugates were comprehensively characterised by HPLC, NMR spectroscopy and mass spectrometry and found to be at least 95 % pure. For the first time, permeation coefficients in a BBB model for organometal–peptide derivatives were determined in this work. The uptake and localisation of fluorescein‐labelled enkephalins was monitored by fluorescence microscopy on three cancer cell lines. Octanol/H₂O partition coefficients of the compounds were measured by HPLC. The introduction of the organometallic moiety enhances the uptake into cells and the permeation coefficient of [Leu⁵]‐enkephalin. This could be due to an increase in lipophilicity caused by the organometallic label. The metal–peptide conjugates were found to be nontoxic up to mM concentrations. The low cytotoxicity encourages further experiments that could take advantage of the selectivity of enkephalin derivatives for opioid receptors.     

Combined Treatment with Dif1stat<Superscript>®</Superscript> and Diet Reduce Plasma Lipid Indicators of Moderate Hypercholesterolemia More Effectively than Diet Alone: A Randomized Trial in Parallel Groups

An open-labeled randomized trial with parallel groups was carried out to study the effects of Dif1stat^® (Monascus purpureus–Linear aliphatic alcohols–Niacin) in the treatment of primary moderate hypercholesterolemia. The trial lasted 8 months. The patients, males and females, were assigned to two groups: A (#130), treated with diet, and B (#110) submitted to diet + Dif1stat^®. After 4 months, group A did not show significant changes in Total cholesterol (TC), LDL-cholesterol (LDLC), HDL-cholesterol (HDLC) or non-HDL-cholesterol (non-HDLC). The same group, showed a reduction in TC (–22%), LDLC (–30%) and non-HDLC (–27%) after 8 months (P ≤ 0.001). After 4 months, TC (–21.3%), LDLC (–29%), and non-HDLC (–26%) were significantly lowered in group B (P ≤ 0.001). In group B, TC, LDLC and non-HDLC showed a further reduction after 8 months: –29.4, –38 and –37%, respectively (P ≤ 0.001). Even triglycerides (TG) decreased significantly (–33%) (P ≤ 0.001). After 8 months, group B showed a significant reduction of TG (–33%) (P ≤ 0.001), when compared to group A. Some safety parameters were significantly reduced in both groups: AST and γ-GT in group A after 4 and 8 months, as well as ALT, AST and γ-GT in group B after 8 months (P ≤ 0.001). Dif1stat^®, given with a suitable diet, was well tolerated in the long-term and induced an anti-atherogenic plasma lipid and lipoprotein profile, in patients with moderate hypercholesterolemia.     

Arch-Free flow in aerated silo discharge of cohesive powders

Arching can occur during silo discharge of cohesive powders. In general this happens when the outlet size is not wide enough. Flow aid devices, such as aeration pads, are commonly used in the industry to achieve proper flow of cohesive materials. However, no design criteria are presently available for such kind of devices and, in particular, for the intensity of aeration to be used to avoid arching. Aim of this paper is the evaluation of the limiting aeration condition to produce the collapse of established arches and the minimum aeration rate necessary for no arching discharge flow. Experimental tests are carried out in an aerated flat bottom silo. The measured quantities are the aeration rate at arch collapse and the arch size. Powder permeability is characterized by fluidization experiments. A simplified model is proposed to assess on the prevailing physical phenomena and predictively evaluate the minimum aeration rate to determine no arching discharge flow.