Search

Pork-cat syndrome can occur in children younger than 10 years. A history of contact with animals since infancy and history of severe atopic dermatitis, which can promote epicutaneous sensitization to animal serum albumin, may be helpful in diagnosis.

Extinction of strained chain-branching premixed flames with nonunity fuel and chain-carrier Lewis numbers is asymptotically analyzed by employing an NEF (Nearly Equidiffusional Flame) limit modified specifically for the Zel'dovich-Liñán two-step mechanism. The asymptotic chain-branching flame-structure analysis is carried out within the framework of the intermediate recombination regime, in which the recombination layer is asymptotically thicker than the inner chain-branching layer, but thinner than the outer convective-diffusive layer. In order to construct a consistent activation-energy asymptotics for the thinnest chain branching layer, thickness of the intermediate recombination-layer as well as deviation of the chain-carrier Lewis number from unity is scaled by the inverse square root of the chain-branching Zel'dovich number. Because the fuel is consumed only by the chain-branching reaction, characterized by a large chain-branching Zel'dovich number, the influences of nonunity fuel Lewis number on extinction with two-step chemistry is found to be qualitatively almost identical to that with overall one-step chemistry. Therefore, strained chain-branching flames can be extinguished by increasing the flow strain rate if the fuel Lewis number is sufficiently large. However, the chain-carrier Lewis number is found to be not capable of qualitatively influencing the extinction characteristics because the peak chain-carrier concentration tends to remain almost invariant with varying flow strain rate. Abrupt extinction is more readily observed for the faster recombination regime, for which the overall effective nonlinearity of the two-step mechanism becomes larger. Finally, the critical Lewis number boundary for extinction is predominantly dependent on the fuel Lewis number. Consequently, the overall extinction characteristics of strained chain-branching flames is found to be qualitatively similar to that found within the framework of the overall single-step activation-energy asymptotics. [ABSTRACT FROM AUTHOR]

This paper presents a circuit for detecting and protecting against short circuits in E-mode gallium nitride high-electron-mobility transistors (GaN HEMTs) and analyzes the protection performance of the circuit. GaN HEMTs possess fast switching characteristics that enable high efficiency and power density in power conversion devices. However, these characteristics also pose challenges in protecting against short circuits and overcurrent situations. The proposed method detects short-circuit events by monitoring an instantaneous drop in the DC bus voltage of a circuit with GaN HEMTs applied and uses a bandpass filter to prevent the malfunction of the short-circuit protection circuit during normal switching and ensure highly reliable operation. Using this method, the short-circuit detection time of E-mode GaN HEMTs can be reduced to 257 ns, successfully protecting the device without malfunctions even in severe short-circuit situations occurring at high DC link voltages. [ABSTRACT FROM AUTHOR]

Cohesin is an essential multiprotein complex that mediates sister chromatid cohesion critical for proper segregation of chromosomes during cell division. Cohesin is also involved in DNA double-strand break (DSB) repair. In mammalian cells, cohesin is involved in both DSB repair and the damage checkpoint response, although the relationship between these two functions is unclear. Two cohesins differing by one subunit (SA1 or SA2) are present in somatic cells, but their functional specificities with regard to DNA repair remain enigmatic. We found that cohesin-SA2 is the main complex corecruited with the cohesin-loading factor NIPBL to DNA damage sites in an S/G(2)-phase-specific manner. Replacing the diverged C-terminal region of SA1 with the corresponding region of SA2 confers this activity on SA1. Depletion of SA2 but not SA1 decreased sister chromatid homologous recombination repair and affected repair pathway choice, indicating that DNA repair activity is specifically associated with cohesin recruited to damage sites. In contrast, both cohesin complexes function in the intra-S checkpoint, indicating that cell cycle-specific damage site accumulation is not a prerequisite for cohesin's intra-S checkpoint function. Our findings reveal the unique ways in which cohesin-SA1 and cohesin-SA2 participate in the DNA damage response, coordinately protecting genome integrity in human cells.

Proper recognition and repair of DNA damage is critical for the cell to protect its genomic integrity. Laser microirradiation ranging in wavelength from ultraviolet A (UVA) to near-infrared (NIR) can be used to induce damage in a defined region in the cell nucleus, representing an innovative technology to effectively analyze the in vivo DNA double-strand break (DSB) damage recognition process in mammalian cells. However, the damage-inducing characteristics of the different laser systems have not been fully investigated. Here we compare the nanosecond nitrogen 337 nm UVA laser with and without bromodeoxyuridine (BrdU), the nanosecond and picosecond 532 nm green second-harmonic Nd:YAG, and the femtosecond NIR 800 nm Ti:sapphire laser with regard to the type(s) of damage and corresponding cellular responses. Crosslinking damage (without significant nucleotide excision repair factor recruitment) and single-strand breaks (with corresponding repair factor recruitment) were common among all three wavelengths. Interestingly, UVA without BrdU uniquely produced base damage and aberrant DSB responses. Furthermore, the total energy required for the threshold H2AX phosphorylation induction was found to vary between the individual laser systems. The results indicate the involvement of different damage mechanisms dictated by wavelength and pulse duration. The advantages and disadvantages of each system are discussed.

The asymptotic structure of stretched chain-branching premixed flames with unity Lewis numbers is analyzed with the Zel'dovich-Liñán two-step mechanism, including (I) temperature-sensitive autocatalytic chain-branching step and (II) first-order chain-recombination step with combustion heat release. Depending on the order-of-magnitude of the Damköhler number ratio between the branching and recombination reactions, three distinct asymptotic limits, namely the fast, intermediate and slow recombination regimes, emerge with their own distinct multi-layer asymptotic structures. Our attention is focused on the asymptotic chain-branching flame-structure analysis within the framework of the intermediate recombination regime, in which the recombination layer is asymptotically thicker than the branching layer, but thinner than the outer convective-diffusive layer. The multi-layer asymptotics, involving the Damköhler number asymptotics for the recombination layer and the activation-energy asymptotics for the branching layer, yields the chain-branching flame-structure solution. The calculation results reveal the unique characteristics of strained chain-branching flames. First, the chain-carrier concentration and temperature at the branching reaction sheet are found to be constant irrespective of the strain rate. The chain-carrier concentration increases as the recombination reaction becomes slower. Moreover, the chain-carrier concentration at the branching reaction sheet is found to be proportional to the laminar flame speed. However, no quasisteady extinction was observed in any calculation results because the branching-reaction rate manages to maintain its strength thanks to the invariant branching-layer temperature. It is worthwhile to note that the present two-step model for chain-branching flames is perhaps the simplest asymptotic model, involving the minimum number of kinetic parameters to properly describe the asymptotic structure without losing any physical essence. [ABSTRACT FROM AUTHOR]

Calcium silicate-based cement (CSC) is a pharmaceutical agent that is widely used in dentistry. This bioactive material is used for vital pulp treatment due to its excellent biocompatibility, sealing ability, and antibacterial activity. Its drawbacks include a long setting time and poor maneuverability. Hence, the clinical properties of CSC have recently been improved to decrease its setting time. Despite the widespread clinical usage of CSC, there is no research comparing recently developed CSCs. Therefore, the purpose of this study is to compare the physicochemical, biological, and antibacterial properties of four commercial CSCs: two powder–liquid mix types (RetroMTA® [RETM]; Endocem® MTA Zr [ECZR]) and two premixed types (Well-Root™ PT [WRPT]; Endocem® MTA premixed [ECPR]). Each sample was prepared using circular Teflon molds, and tests were conducted after 24 h of setting. The premixed CSCs exhibited a more uniform and less rough surface, higher flowability, and lower film thickness than the powder–liquid mix CSCs. In the pH test, all CSCs showed values between 11.5 and 12.5. In the biological test, cells exposed to ECZR at a concentration of 25% showed greater cell viability, but none of the samples showed a significant difference at low concentration (p > 0.05). Alkaline phosphatase staining revealed that cells exposed to ECZR underwent more odontoblast differentiation than the cells exposed to the other materials; however, no significant difference was observed at a concentration of 12.5% (p > 0.05). In the antibacterial test, the premixed CSCs showed better results than the powder–liquid mix CSCs, and ECPR yielded the best results, followed by WRPT. In conclusion, the premixed CSCs showed improved physical properties, and of the premixed types, ECPR exhibited the highest antibacterial properties. For biological properties, none of these materials showed significant differences at 12.5% dilution. Therefore, ECPR may be a promising material with high antibacterial activity among the four CSCs, but further investigation is needed for clinical situations. [ABSTRACT FROM AUTHOR]

Schisandra chinensis (Turcz.) Baill. has been traditionally used as a medicine for bronchial tube ailments in Northeast Asia. Recently, the demand for S. chinensis has increased for use as food and medicine because of the lignans found in its fruits. However, the species germplasm collection has rarely been studied to evaluate their phenotypic traits in Korea. In this study, 96 accessions of S. chinensis were collected in South Korea for two years to evaluate their phenotypes, and principal component analysis (PCA) and cluster analysis were conducted. Significant variations among the measured phenotypic traits were observed. The total bunch weight produced from a single tree ranged from 109 to 5844 g; the contents in schizandrin, gomisin A, and gomisin N—three types of lignan—were 2.2–14.5, 0.9–9.8, and 2.1–12.2 mg/g, respectively. Gomisin N positively correlated with flowering traits (flowering start, period, and peduncle length) and leaf characteristics (leaf width and length). PCA and cluster analyses revealed four clusters among the 96 S. chinensis accessions. These results provide valuable information for systematic characterization of species germplasm collections and tools for further research. [ABSTRACT FROM AUTHOR]