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High Temperature Deformation Behavior of 8090 Al-Li Alloy

High temperature deformation behavior, especially the superplasticity of an 8090 Al-Li alloy, was studied within the recent framework of the internal variable theory of structural superplasticity. In this study, a series of load relaxation tests were conducted at various temperatures ranging from 200°C to 530°C to obtain the flow curves of log ε˙ versus log ε. The effect of grain size was also examined by varying the grain sizes through a proper thermomechanical treatment. The flow curves were found to be composite curves consisting of contributions from grain boundary sliding (GBS) and grain matrix deformation (GMD) at superplastic temperatures. The activation energy obtained for GMD was 124.9 kJ/mole in the temperature range from 470°C to 530°C, very similar to that for self-diffusion in pure Al

Intra-abdominal angiosarcoma developing in a capsule of a foreign body: report of a case with associated hemorrhagic diathesis

BACKGROUNDS: Angiosarcoma occurs very rarely in the gastrointestinal tract and can present great diagnostic difficulty, especially when it is associated with intraabdominal abscess or granulation tissue. CASE PRESENTATION: We report a case where the angiosarcoma was diagnosed after the occurrence of disseminated angiosarcoma and concurrent hemoperitoneum. The tumor developed in the fibrous capsule of a foreign body, which was possibly related to the previous appendectomy twenty years ago, and became a widely disseminated malignant neoplasm in the abdomen. After the operation, the patient's course was dominated by a fatal consumptive coagulapathy. Pathologic examination of the multiple intra-abdominal lesions showed the histological and immunohistological characteristics of the angiosarcoma. CONCLUSION: Even though angiosarcoma in the gastrointestinal tract is extremely rare, when dealing with intraabdominal abscess or the gastrointestinal bleeding in patients who have undergone surgery or radiation therapy in the past, the possibility of angiosarcoma should be considered. To make the definite diagnosis of angiosarcoma and to avoid the misdiagnosis of foreign body granuloma, thorough histological examination and immunohistochemical staining may be prerequisite

Alpha-tocopherol exerts protective function against the mucotoxicity of particulate matter in amphibian and human goblet cells

Exposure to particulate matter (PM) in ambient air is known to increase the risk of cardiovascular disorders and mortality. The cytotoxicity of PM is mainly due to the abnormal increase of reactive oxygen species (ROS), which damage cellular components such as DNA, RNA, and proteins. The correlation between PM exposure and human disorders, including mortality, is based on long-term exposure. In this study we have investigated acute responses of mucus-secreting goblet cells upon exposure to PM derived from a heavy diesel engine. To this end, we employed the mucociliary epithelium of amphibian embryos and human Calu-3 cells to examine PM mucotoxicity. Our data suggest that acute exposure to PM significantly impairs mucus secretion and results in the accumulation of mucus vesicles in the cytoplasm of goblet cells. RNA-seq analysis revealed that acute responses to PM exposure significantly altered gene expression patterns; however, known regulators of mucus production and the secretory pathway were not significantly altered. Interestingly, pretreatment with alpha-tocopherol nearly recovered the hyposecretion of mucus from both amphibian and human goblet cells. We believe this study demonstrates the mucotoxicity of PM and the protective function of alpha-tocopherol on mucotoxicity caused by acute PM exposure from heavy diesel engines

SENSING MECHANISM AND APPLICATION OF MECHANICAL STRAIN SENSOR: A MINI-REVIEW

This study reviews the potential of flexible strain sensors based on nanomaterials such as carbon nanotubes (CNTs), graphene, and metal nanowires (NWs). These nanomaterials have excellent flexibility, conductivity, and mechanical properties, which enable them to be integrated into clothing or attached to the skin for the real-time monitoring of various activities. However, the main challenge is balancing high stretchability and sensitivity. This paper explains the basic concept of strain sensors that can convert mechanical deformation into electrical signals. Moreover, this paper focuses on simple, flexible, and stretchable resistive and capacitive sensors. It also discusses the important factors in choosing materials and fabrication methods, emphasizing the crucial role of suitable polymers in high-performance strain sensing. This study reviews the fabrication processes, mechanisms, performance, and applications of stretchable strain sensors in detail. It analyzes key aspects, such as sensitivity, stretchability, linearity, response time, and durability. This review provides useful insights into the current status and prospects of stretchable strain sensors in wearable technology and human–machine interfaces

Effect of Technological Atmosphere of Fashion Store on Online Behavior Intention: Focusing on AIDMSAS Model

Since the 1960s in-store atmospheric stimuli (e.g. color, music, and scent) have been investigated in the fashion retailing literature by reason of the great influence on consumers\u27 emotion and purchase behavior. Moreover, to increase consumers\u27 positive emotion, the experience economy by Pine and Gilmore (1999) indicates the importance of consumers\u27 in-store experiences. Enhancing consumer experience often links to in-store design aspects. To maximize consumers\u27 experience, various retailers try to adopt technology such as digital display, touch screen, augmented reality space and 3D virtual model in an offline store. Entering the era of omni-channel as seamless integrated channel from multi-channel retail environment, this study is considerably significant in that in-store experience affect customers\u27 online behavior. Technology has steadily and rapidly developed, and the use of technology in fashion retail will likely continue to spread. However, there are only few studies on the effect of technological atmosphere of a store on consumer behavior. This study, therefore, aims to identify the influence of technological atmospheric fashion store on consumer behavior including online behavior intention and purchase intention. This research demonstrates the pivotal role of in-store technology application in that purchase enhancement or an effect of e-word-of-mouth by sharing one\u27s experience. Also, it can even redound to products at stores. Hence, from the practical standpoint, implementing innovative technology features enhances customers\u27 positive attitude toward stores and products as well as the online application intention

Glucose repression of the Escherichia coli sdhCDAB operon, revisited: regulation by the CRP·cAMP complex

Expression of the Escherichia coli sdhCDAB operon encoding the succinate dehydrogenase complex is regulated in response to growth conditions, such as anaerobiosis and carbon sources. An anaerobic repression of sdhCDAB is known to be mediated by the ArcB/A two-component system and the global Fnr anaerobic regulator. While the cAMP receptor protein (CRP) and Cra (formerly FruR) are known as key mediators of catabolite repression, they have been excluded from the glucose repression of the sdhCDAB operon. Although the glucose repression of sdhCDAB was reported to involve a mechanism dependent on the ptsG expression, the molecular mechanism underlying the glucose repression has never been clarified. In this study, we re-examined the mechanism of the sdhCDAB repression by glucose and found that CRP directly regulates expression of the sdhCDAB operon and that the glucose repression of this operon occurs in a cAMP-dependent manner. The levels of phosphorylated enzyme IIA(Glc) and intracellular cAMP on various carbon sources were proportional to the expression levels of sdhC-lacZ. Disruption of crp or cya completely abolished the glucose repression of sdhC-lacZ expression. Together with data showing correlation between the intracellular cAMP concentrations and the sdhC-lacZ expression levels in several mutants and wild type, in vitro transcription assays suggest that the decrease in the CRP·cAMP level in the presence of glucose is the major determinant of the glucose repression of the sdhCDAB operon