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Duplex stainless steels, known for their excellent corrosion resistance, are employed in a variety of chloride solutions-acidic, neutral, and alkaline-due to a stable passive film that forms on their surfaces. This study involved polarization tests, EIS (Electrochemical Impedance Spectroscopy) measurements, Mott-Schottky plots, and XPS (X-Ray Photoelectron Spectroscopy) analyses in both static and dynamic conditions across acidic (1NaCl + 0.1N HCl, pH 1.0), neutral (1N NaCl, pH 6.7), and alkaline (1N NaCl + 0.1N NaOH, pH 13.2) chloride solutions to confirm that duplex stainless steels exhibit similar passivation behavior (0.79 μA/cm 2 > i p > 0.2 μA/cm 2 and 590 kΩ·cm 2 < R p < 651 kΩ·cm 2 ). Regardless of the pH of the solution, p-type and n-type semiconductive properties were observed, but the balance of the semiconductive tendencies was different. Comparing passive films formed under dynamic conditions, through real-time HCl injection into a neutral chloride solution, with those formed under static conditions, revealed that both conditions yield similar structural and property characteristics in the films, as well as comparable electrochemical behaviors. These findings suggest that the passive film on the stainless steel surface adjusts to the environment and can be spontaneously repassivated in response to environmental changes.

Wire bonding, one of the methods for electrically connecting a semiconductor chip with a substrate, involves attaching thin metal wires to pads. It is the oldest electrical connection method that exhibits high compatibility with other processes. The metal wires used for electrical connection in wire bonding are mainly made of Au, Cu, and Ag. After the wire bonding, molding is performed using the epoxy molding compound (EMC). However, EMC inevitably contains ions such as halogen elements. In addition, it absorbs moisture due to its hydrophilicity, creating a corrosive environment with electrolytes. In this study, we evaluated the influence of hydrochloric acid concentration on corrosion behavior between Au or Cu bonding wires and sputtered Al bond pads. The electrochemical factors such as corrosion potential difference (ΔE), galvanic corrosion current density (i g ), and anodic and cathodic Tafel slopes were found to influence galvanic corrosion behavior. Galvanic corrosion tendency in first bond and second bond areas of PCB unit specimen was confirmed.

Dry canisters used in nuclear power plants can be subject to localized corrosion, including stress corrosion cracking. External and residual tensile stress can facilitate the occurrence of stress corrosion cracking. Residual stress can arise from welding and plastic deformation. Mitigation methods of residual stress depend upon the energy used and include laser peening, ultrasonic peening, ultrasonic nanocrystal surface modification, shot peening, or water jet peening. Among these, laser peening technology irradiates a continuous laser beam on the surface of metals and alloys at short intervals to add compressive residual stress as a shock wave is caused. This research studied the effect of laser peening with/without a thin aluminum layer on the corrosion properties of welded 304L stainless steel. The intergranular corrosion rate of the laser-peened specimen was a little faster than the rate of the non-peened specimen. However, laser peening enhanced the polarization properties of the cross-section of 304L stainless steel, while the properties of the surface were reduced by laser peening. This behavior was discussed on the basis of the microstructure and residual stress.

Objectives: This study investigated whether employing a phonological or semantic strategy elicited a better performance on a letter fluency task for people with Alzheimer's disease (AD)., Methods: Sixty participants with probable AD were extracted from the DementiaBank database. After applying exclusion criteria, 47 participants were included in the final analysis. We used phonological and semantic strategies to analyze participants' responses to the letter fluency task. The phonological strategy analysis was based on the number of switches and the mean cluster size, and the semantic strategy analysis was based on semantic relatedness, which quantified word-similarity change by adapting the concept of persistence length from analyses of DNA and protein structures. We employed Pearson correlation coefficients to determine whether any strategy indexes were significantly related to the number of correct responses and used stepwise multiple regression analyses to determine the best predictor., Results: Participants who relied on phonological strategy performed better on the letter fluency task. The number of correct responses was significantly positively correlated with phonological strategy but significantly negatively correlated with semantic strategy. The number of switches, mean cluster size, and semantic relatedness were all significant predictors, explaining 68.1% of the variance., Conclusion: Our results suggested that individuals with AD who engaged in phonological strategy performed better on the letter fluency task than those who relied on semantic strategy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Park, Yoo, Lim and Sung.)

The introduction of tensile residual stress has led to the induction of damage such as fatigue, corrosion fatigue, and stress corrosion cracking (SCC) in stainless steel in association with the influence of environments, components, surface defects, and corrosive factors during its use. Compressive residual stress can be achieved through various techniques. Among several methods, laser peening can be more attractive as it creates regularity on the surface with a high-quality surface finish. However, there is very little research on heavily peened surface and cross-section of stainless steel with very deep compressive residual stress. This work focused on welding and laser peening and the influence of Al coating on the microstructural changes in 304L stainless steel. The specimen obtained by laser peening had a very deep compressive residual stress of over 1 mm and was evaluated based on microstructural and hardness analysis. Therefore, a model for microstructural change by laser peening on welded 304L stainless steel was proposed.

Background: We investigated how two distinct mutations in SCN1A differentially affect electrophysiological properties of the patient-derived GABAergic neurons and clinical severities in two Dravet syndrome (DS) patients., Materials and Methods: We established induced pluripotent stem cells from two DS patients with different mutations in SCN1A and subsequently differentiated them into forebrain GABAergic neurons. Functionality of differentiated GABAergic neurons was examined by electrophysiological recordings., Results: DS-1 patient had a missense mutation, c.4261G > T [GenBank: NM&#95;006920.4] and DS-2 patient had a nonsense frameshift mutation, c.3576&#95;3580 del TCAAA [GenBank: NM&#95;006920.4]. Clinically, contrary to our expectations, DS-1 patient had more severe symptoms including frequency of seizure episodes and the extent of intellectual ability penetration than DS-2 patient. Electrophysiologic recordings showed significantly lower sodium current density and reduced action potential frequency at strong current injection (>60 pA) in GABAergic neurons derived from both. Intriguingly, unique genetic alterations of SCN1A differentially impacted electrophysiological impairment of the neurons, and the impairment's extent corresponded with the symptomatic severity of the donor from which the iPSCs were derived., Conclusion: Our results suggest the possibility that patient-derived iPSCs may provide a reliable in vitro system that reflects clinical severities in individuals with DS., (Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Many extracellular matrix proteins have positive influences on the adhesion, proliferation, and differentiation of stem cells into specific cell linages. Fibulin-1 (FBLN1), a member of a growing family of extracellular glycoproteins, contributes to the structure of the extracellular matrix. Here, we investigated the effect of FBLN1 on the ability of human nasal inferior turbinate-derived mesenchymal stem cells (hTMSCs) to undergo osteogenic differentiation. After we generated recombinant FBLN1, the characteristics of FBLN1-treated hTMSCs were evaluated using MTT assay, ALP and mineralization activities, and quantitative real-time PCR. FBLN1 significantly enhanced the adhesion activity (p < 0.001) and proliferation of hTMSCs (p < 0.05). The ALP and mineralization activities of cells were dramatically increased (p < 0.01) after 9 and 12 days of FBLN1 treatment, respectively. This indicated the ability of FBLN1 to induce hTMSCs to differentiate into osteoblasts. Furthermore, increasing the mRNA levels of osteogenic marker genes, such as a transcriptional coactivator with a PDZ-binding motif (TAZ), alkaline phosphatase (ALP), collagen type I (Col I), and osteocalcin (OCN), improved bone repair and regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2291-2298, 2017., (© 2017 Wiley Periodicals, Inc.)

Fibronectin (FN) contributes to cell adhesion, proliferation, and differentiation in various cell types. To enhance the activity of fibronectin at the sites of focal adhesion, we engineered a novel recombinant fibronectin (FNIII10) fragment connected to the peptide amphiphile sequence (PA), LLLLLLCCCGGDS. In this study, the effects of FNIII10-PA on rat mesenchymal stem cells (rMSCs) were compared with those of FNIII10. FNIII10-PA showed the prominent protein adhesion activity. In addition, FNIII10-PA showed a significantly higher effect on adhesion, proliferation, and differentiation of rMSCs than FNIII10. Taken together, the FNIII10-containing self-assembled sequence enhanced rMSCs adhesion, proliferation, and differentiation.

Dye sensitized solar cells (DSSC) with surface modified carbon fiber fabric (CF) counter electrodes were prepared and tested. Four different type of CF were used; carbon fiber (CF); carbon fiber etched with NaOH (ECF); carbon fiber with thermally deposited platinum (CFPt); and carbon fiber etched with NaOH followed by thermal deposition of platinum (ECFPt). For comparison, DSSC with thermally Pt deposited fluorine doped tin oxide (FTO/Pt) glass counter electrode was also prepared and tested. Scanning electron microscope (SEM) proved that surface morphology of the carbon fiber was roughened by the etching process and platinum deposition process. The I-V curves of each DSSC were measured under simulated light (1 Sun, AM 1.5) to get open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF) and efficiency (eta). Electrochemical impedance spectroscopy of each cell was measured also. It was found that higher efficiency is obtained in order of using ECFPt > CFPt > FTO/Pt > ECF > CF counter electrode.

Biometals need high corrosion resistance since metallic implants in the body should be biocompatible and metal ion release should be minimized. In this work, we designed three kinds of super stainless steel and adjusted the alloying elements to obtain different microstructures. Super stainless steels contain larger amounts of Cr, Mo, W, and N than commercial alloys. These elements play a very important role in localized corrosion and, thus, their effects can be represented by the "pitting resistance equivalent number (PREN)." This work focused on the behavior which can arise when the bare surface of an implant in the body is exposed during walking, heavy exercise, and so on. Among the experimental alloys examined herein, Alloy Al and 316L stainless steels were mildly cytotoxic, whereas the other super austenitic, duplex, and ferritic stainless steels were noncytotoxic. This behavior is primarily related to the passive current and pitting resistance of the alloys. When the PREN value was increased, the passivation behavior in simulated body solution was totally different from that in acidic chloride solution and, thus, the Cr(2)O(3)/Cr(OH)(3) and [Metal oxide]/[Metal + Metal oxide] ratios of the passive film in the simulated body solution were larger than those in acidic chloride solution. Also, the critical current density in simulated body solution increased and, thus, active dissolution may induce metal ion release into the body when the PREN value and Ni content are increased. This behavior was closely related to the presence of EDTA in the simulated body solution., ((c) 2007 Wiley Periodicals, Inc.)

We previously reported that protein kinase C (PKC) activation induced meiotic maturation (germinal vesicle breakdown, GVBD) of Rana dybowskii follicular oocytes cultured in vitro without hormone treatment. The experiments reported here were carried out to establish whether ovarian follicles ovulated in response to PKC activation during culture. A phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was used for PKC activation. TPA addition (10 microM) to cultured ovarian fragments induced ovulation and maturation of the oocytes similar to that seen following addition of frog pituitary homogenate (FPH, 0.05 pituitary/ml) or progesterone (0.5 microgram/ml). Such changes were not observed when ovarian fragments were treated with inactive phorbol ester. The time course of TPA-induced ovulation was similar to that produced by FPH-stimulated ovulation. Both TPA- and FPH-stimulated ovulation and maturation were blocked by treatment with cycloheximide, forskolin (an adenylate cyclase stimulator), and 1-(5-isoquinolinylsulfonyl)-2-methyl-piperazine (H-7; a PKC inactivator). FPH treatment markedly increased progesterone levels in the medium during ovarian fragment culture whereas TPA treatment failed to elevate progesterone levels. Thus, TPA treatment mimics FPH and progesterone in inducing ovulation and meiotic maturation in cultured amphibian ovarian fragments. The data strongly suggest that PKC plays an important role in regulating ovulation as well as in modulating amphibian oocyte maturation during follicular differentiation.