Human umbilical artery smooth muscle exhibits a 2-apb- sensitive capacitative contractile response evoked by vasoactive substances and exprsses mrnas for stim,orai and trpc channelsa

After depletion of intracellular Ca²⁺ stores the capacitative response triggers an extracellular Ca²⁺ influx through store-operated channels (SOCs) which refills these stores. Our objective was to explore if human umbilical artery smooth muscle presented this response and if it was involved in the mechanism of serotonin- and histamine-induced contractions. Intracellular Ca²⁺ depletion by a Ca²⁺-free extracellular solution followed by Ca²⁺ readdition produced a contraction in artery rings which was inhibited by the blocker of Orai and TRPC channels 2-aminoethoxydiphenyl borate (2-APB), suggesting a capacitative response. In presence of 2-APB the magnitude of a second paired contraction by serotonin or histamine was significantly less than a first one, likely because 2-APB inhibited store refilling by capacitative Ca²⁺ entry. 2-APB inhibition of sarcoplasmic reticulum Ca²⁺ release was excluded because this blocker did not affect serotonin force development in a Ca²⁺-free solution. The PCR technique showed the presence of mRNAs for STIM proteins (1 and 2), for Orai proteins (1, 2 and 3) and for TRPC channels (subtypes 1, 3, 4 and 6) in the smooth muscle of the human umbilical artery. Hence, this artery presents a capacitative contractile response triggered by stimulation with physiological vasoconstrictors and expresses mRNAs for proteins and channels previously identified as SOCs.     

C.E.R.A. once every 4 weeks in patients with chronic kidney disease not on dialysis: The ARCTOS extension study

C.E.R.A., a continuous erythropoietin receptor activator is approved for the treatment of anemia in patients with chronic kidney disease (CKD). The ARCTOS (administration of C.E.R.A. in CKD patients to treat anemia with a twice‐monthly schedule) phase 3 study demonstrated the efficacy and safety of C.E.R.A. in correcting anemia when administered once every 2 weeks (Q2W) subcutaneously in patients with CKD not on dialysis. We assessed the feasibility and long‐term safety of converting patients who responded to treatment with C.E.R.A. Q2W to C.E.R.A. once every 4 weeks (Q4W) during a 24‐week extension period. After the core ARCTOS study period (28 weeks), 296 patients entered the 24‐week extension period. At week 29, patients who responded to C.E.R.A. Q2W during the core period were rerandomized to receive subcutaneous C.E.R.A. Q2W or Q4W. Patients in the comparator arm could receive darbepoetin alfa once weekly or Q2W. Dosage was adjusted to maintain hemoglobin (Hb) between 11 and 13 g/dL. Mean Hb levels remained stable in all groups, and were comparable at the end of the extension period (mean [standard deviation], C.E.R.A. Q2W, 11.92 [0.90] g/dL; C.E.R.A. Q4W, 11.70 [0.86] g/dL; darbepoetin alfa, 11.89 [0.98] g/dL). Mean within‐patient standard deviation values for Hb were also comparable in all groups (0.66, 0.62, and 0.65 g/dL for C.E.R.A. Q2W, C.E.R.A. Q4W and darbepoetin alfa, respectively). All treatments were well tolerated. Subcutaneous C.E.R.A. Q4W is safe and effective in maintaining stable Hb levels in patients with CKD not on dialysis following correction with subcutaneous C.E.R.A. Q2W.     

Analytical separation for the TE and TM modes of a two-concentric-core optical fibre

This paper describes the determination of the analytical solution for the TE and TM modes of a two-concentric-core fibre. This fibre, in contrast to the multi-clad one, has a layer where it is assumed that guided modes exist. Based on techniques which are already known and with the aid of computational analytic support, separation of the dispersion equation for the modes TE and TM is achieved.     

Metformin and colorectal cancer

Colorectal cancer (CRC) is one of the main causes of cancer-related mortality in the developed world despite recent developments in detection and treatment. Several epidemiological studies indicate that metformin, a widely prescribed antidiabetic drug, exerts a protective effect on different cancers including CRC. Furthermore, a recent double-blind placebo-controlled, randomized trial showed that metformin significantly decreased colorectal adenoma recurrence. Studies exploring the mechanism of action of metformin in cells derived from different types of cancers reported many effects including respiratory chain complex 1 inhibition, Akt phosphorylation inhibition, ATP depletion, PKA activation and Wnt signaling inhibition. However, many of these results were obtained employing metformin at concentrations several fold higher than those achieved in target tissues in diabetic patients receiving therapeutic recommended doses of metformin. In contrast, recent studies obtained with metformin at concentrations compatible with those detected in human intestines revealed that metformin elicit responses that target β-catenin, PI3K/Akt, E-cadherin, p120-catenin and focal adhesion kinase which are key molecules and signaling pathways associated to colorectal cancer development. This brief review revisit several know aspects as well as novel ones on the effects of metformin on cancer cells.     

Phased‐array transducers for damage detection in aircraft structures*

The work outlined in this paper is a part of a wider effort aimed at the development of a built‐in system for real‐time damage detection in aircraft structures. The objective of this study was to show the feasibility of applying low‐frequency phased‐array transducers for damage detection in metallic structures with bonded repairs and, also, in structures made of composite materials. This paper is divided into two main portions: a component dedicated to the monitoring of crack growth under a simulated composite repair and a part describing an introductory study done for composite panels monitoring. The data acquisition system is also described. The results of the study described in this paper indicate that a low‐frequency, built‐in phased‐array system can successfully estimate the length of a crack growing under a bonded repair. Satisfactory results of monitoring simulated defects in composite structures are presented, as well.     

Enhancement of nisin production in milk by conjugal transfer of the protease‐lactose plasmid pLP712 to the wild strain Lactococcus lactis UQ2

Lactococcus lactis UQ2 is a wild nisin A producer isolated from a Mexican cheese that grows poorly in milk. Conjugal matings with L. lactis NCDO712 to transfer the Lac+ Prt+ plasmid pLP712 and selection with nisin and lactose yielded L. lactis NCDO712 NisA+. Naturally rifampicin resistant L. lactis UQ2Rif was isolated to provide an additional selective marker. The identity of a transconjugant L. lactis UQ2Rif Lac+ was confirmed by RAPD‐PCR fingerprinting, nisA PCR amplification, nisin production, presence of pLP712 and phospho‐β‐galactosidase activity. This strain performed well in milk and synthesised 200 IU/mL nisin, 40 times more than the original strain.     

Effect of substrate rotation speed on structure and properties of Al-doped ZnO thin films prepared by rf-sputtering

Al-doped ZnO (AZO) thin films were deposited on glass substrates by rf-sputtering at room temperature. The effects of substrate rotation speed (ω_S) on the morphological, structural, optical and electrical properties were investigated. SEM transversal images show that the substrate rotation produces dense columnar structures which were found to be better defined under substrate rotation. AFM images show that the surface particles of the samples formed under substrate rotation are smaller and denser than those of a stationary one, leading to smaller grain sizes. XRD results show that all films have hexagonal wurtzite structure and preferred c-axis orientation with a tensile stress along the c-axis. The average optical transmittance was above 90% in UV-Vis region. The lowest resistivity value (8.5×10^?3 Ω·cm) was achieved at ω_S=0 r/min, with a carrier concentration of 1.8×10²⁰ cm^?3, and a Hall mobility of 4.19 cm²/(V·s). For all other samples, the substrate rotation induced changes in the carrier concentration and Hall mobility which resulted in the increasing of electrical resistivity. These results indicate that the morphology, structure, optical and electrical properties of the AZO thin films are strongly affected by the substrate rotation speed.     

Electrochemical incineration of oxalic acid: Reactivity and engineering parameters

Mass transfer measurements were carried out to test a disk-shaped parallel-plate electrochemical cell, based on a new design. The impinging-jet-cell concept, confined between parallel plates, was adapted to a configuration with one central inlet and several peripheral exit sections, leading to more effective hydrodynamics within the cell. Measurements of mass transfer coefficient were performed using the limiting diffusion current technique based on ferro-cyanide ion oxidation, and overall mass transfer coefficients were correlated to Reynolds numbers ranging from 30 to 200.  A comparison with literature on similar devices showed higher mass transfer coefficients can be obtained in the cell described in the present work. From the mass transfer standpoint, this type of cell could be a valuable tool in electrochemical wastewater treatment applications.  The electrochemical oxidation of oxalic acid was tested at different anode materials (Pb/PbO₂, boron-doped diamond, Ti/Pt and Ti/IrO₂–Ta₂O₅), showing that the new cell design enables limitations usually encountered with conventional batch cells to be overcome. However, the nature of the anode material remains an important parameter for the elimination of organic substrates.