Despite the industrial significance of grain boundary serration for improving creep resistance and retarding crack propagation, the mechanism of grain boundary serration during hot deformation is ...still unclear. The results of several studies indicated that increased inhomogeneity of the stored energy under high-stress deformation suppressed grain boundary serration. Thus, traditional strain-induced boundary migration, in which the stored energy difference between adjacent grains acts as the driving force for grain boundary serration, must be modified for hot deformation. The experimental results of this study suggested that dissociated grain boundary dislocations from lattice dislocations, rather than the elastic energy of the lattice dislocations, cause the nucleation of serrated grain boundaries. Grain boundary sliding on the serrated grain boundary asymmetrically generated an elastic energy field and an accommodated serrated grain boundary. The presence of an elastic energy field was predicted by dislocation climbing and statically distributed dislocations near the elastic energy field. Since the asymmetrically deformed serrated grain boundary exhibited sub-migration behavior in the elastic energy field, it was concluded that the applied shear stress (applied by grain boundary sliding) on the serrated grain boundary dominated the growth of serrated grain boundaries until dynamic recrystallization occurred.
•Movement of grain boundary dislocations dissociated from lattice dislocations nucleates grain boundary serration.•Elastic strain field generated by Grain boundary sliding acts as driving force for growth of serrated grain boundary.•Formation of low-angle boundary weaken driving force for growth of serrated grain boundary.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder, featuring social communication deficit and repetitive/restricted behaviors as common symptoms. Its prevalence has continuously ...increased, but, till now, there are no therapeutic approaches to relieve the core symptoms, particularly social deficit. In previous studies, abnormal function of the glutamatergic neural system has been proposed as a critical mediator and therapeutic target of ASD-associated symptoms. Here, we investigated the possible roles of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in autism symptoms using two well-known autistic animal models, Cntnap2 knockout (KO) mice and in utero valproic acid-exposed ICR (VPA) mice. We found that Cntnap2 KO mice displayed decreased glutamate receptor expression and transmission. Contrarily, VPA mice exhibited increased glutamate receptor expression and transmission. Next, we investigated whether AMPAR modulators (positive-allosteric-modulator for Cntnap2 KO mice and antagonist for VPA mice) can improve autistic symptoms by normalizing the aberrant excitatory transmission in the respective animal models. Interestingly, the AMPAR modulation specifically ameliorated social deficits in both animal models. These results indicated that AMPAR-derived excitatory neural transmission changes can affect normal social behavior. To validate this, we injected an AMPAR agonist or antagonist in control ICR mice and, interestingly, these treatments impaired only the social behavior, without affecting the repetitive and hyperactive behaviors. Collectively, these results provide insight into the role of AMPARs in the underlying pathophysiological mechanisms of ASD, and demonstrate that modulation of AMPAR can be a potential target for the treatment of social behavior deficits associated with ASD.
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•The cryogenic impact toughness of binary Al-Mg alloys generally decreases by increasing the Mg content.•Larger grain structure and more large acicular Al6(Fe,Mn) precipitates ...(>10 µm) can degrade the cryogenic impact toughness of an Al-Mg alloy.•Improved planar anisotropy (Δr) and weaker texture are observed in more ductile Al-Mg alloys of smaller Mg level.•More Brass, S, and Copper-oriented grains are developed with some Goss orientation reduction by increasing Mg level in Al alloys.
In this study, the Mg and temperature effects on cryogenic impact toughness of Al-Mg alloys are investigated. Cryogenic Charpy impact tests are conducted for several Al-Mg alloys: AA5083 (=reference), Al-6 Mg, Al-8 Mg, and Al-8.5 Mg. The temperature range is – 196 ˚C to 100 ˚C. In all Al-Mg alloys, the impact toughness is improved at higher temperatures. The Al-6 Mg alloy exhibits the largest impact toughness, whereas the lowest impact toughness is observed in AA5083 over the temperature range. Beyond the Mg content of 6 wt%, the impact toughness of Al-Mg alloys decreases with increasing Mg. The planar anisotropy (Δr) is low in Al-Mg alloys of higher impact toughness. The largest amounts of coarse inclusions (>10 µm) are present in the AA5083, providing favorable cracking sites and thereby its poor impact toughness. The grain size and intergranular Mg segregation do not appear to influence the toughness of Al-Mg alloys. Weaker texture in the most ductile Al-6 Mg appears beneficial to gain more homogeneous deformation and lower Δr. Brass {110} 〈112〉, S {123} 〈634〉, and Copper {112} 〈111〉 textures evolve at the expense of a Goss {110} 〈001〉 weakening by increasing the Mg level. This texture evolution illustrates the toughness degradation of Al-Mg alloys of higher Mg levels.
Fiber‐type solid‐state supercapacitors (FSSCs) are gaining traction as wearable energy storage devices, given their adaptability akin to traditional fibers. Carbon nanotube fibers (CNTFs) generated ...via a liquid crystalline (LC) wet‐spinning process demonstrate outstanding electrical conductivity, mechanical strength, and flexibility. However, their intrinsic “defect‐free” sp2 carbon surface restricts immediate FSSC application, limited by lower specific surface area and scant pseudocapacitive sites. This study develops LC‐spun CNTFs with inherent electrochemical activity, eliminating the need for post‐processing or additional active materials, a requirement typically essential in most previous research. This advancement arises from the wet‐spinning of functionalized CNTs from a LC solution with an exceptionally high concentration of 160 mg mL−1, facilitated by the manipulation of the LC phase transition range. The resultant CNTFs exhibit a refined internal structure, yielding an electrical conductivity of 1.9 MS m−1 and a mechanical strength of 0.93 GPa. Simultaneously, they demonstrate inherent electrical energy storage capabilities with a specific capacitance of 139.4 F g−1 and a volumetric capacitance of 192.4 F cm−3 at 0.5 A g−1. This innovation signifies a step forward in the potential for mass production without the burden of additional materials and steps.
A high‐performance, fiber‐type, solid‐state supercapacitor is developed using functionalized CNTFs, which are fabricated by the wet‐spinning of their liquid crystal phase. These fibers not only possess exceptional physical properties but also exhibit inherent electrochemical activity. The active‐material‐free energy storage device in this study underscores the potential for efficient mass production of fiber‐type energy storage electrodes.
Portevin-Le Chatelier (PLC) effect arises with increasing the Mg content in Al–Mg alloys. Due to the PLC effect, instability in plasticity and negative strain rate sensitivity (nSRS) are encountered ...during the metalworking process of the Al–Mg alloys, which reduce the ductility and formability of the materials. Herein, torsion tests are performed on the Al–Mg alloys with high Mg content to determine the effect of Mg content and processing parameters on the PLC and nSRS effects. Analyses of the flow curves and deformed microstructures reveal that the Mg content and processing parameters affect the dynamic strain aging and PLC effects in Al–Mg alloys. In some combinations of Mg content, temperature, and strain rate, the PLC effect is weakened and nSRS is not observed because the appropriate selection of Mg content and temperature can lower the stacking fault energy of Al–Mg alloy.
The escalating use of security cameras has resulted in a surge in images requiring analysis, a task hindered by the inefficiency and error-prone nature of manual monitoring. In response, this study ...delves into the domain of anomaly detection in CCTV security footage, addressing challenges previously encountered in analyzing videos with complex or dynamic backgrounds and long sequences. We introduce a three-stage deep learning architecture designed to detect abnormalities in security camera videos. The first stage employs a pre-trained convolutional neural network to extract features from individual video frames. Subsequently, these features are transformed into time series data in the second stage, utilizing a blend of bidirectional long short-term memory and multi-head attention to analyze short-term frame relationships. The final stage leverages relative positional embeddings and a custom Transformer encoder to interpret long-range frame relationships and identify anomalies. Tested on various open datasets, particularly those with complex backgrounds and extended sequences, our method demonstrates enhanced accuracy and efficiency in video analysis. This approach not only improves current security camera analysis but also shows potential for diverse application settings, signifying a significant advancement in the evolution of security camera monitoring and analysis technologies.
Autism spectrum disorder (ASD) is a group of pervasive developmental disorders with core symptoms such as sociability deficit, language impairment, and repetitive/restricted behaviors. Although ...worldwide prevalence of ASD has been increased continuously, therapeutic agents to ameliorate the core symptoms especially social deficits, are very limited. In this study, we investigated therapeutic potential of donepezil for ASD using valproic acid-induced autistic animal model (VPA animal model). We found that prenatal exposure of valproic acid (VPA) induced dysregulation of cholinergic neuronal development, most notably the up-regulation of acetylcholinesterase (AChE) in the prefrontal cortex of affected rat and mouse offspring. Similarly, differentiating cortical neural progenitor cell in culture treated with VPA showed increased expression of AChE in vitro. Chromatin precipitation experiments revealed that acetylation of histone H3 bound to AChE promoter region was increased by VPA. In addition, other histone deacetyalse inhibitors (HDACIs) such as trichostatin A and sodium butyrate also increased the expression of AChE in differentiating neural progenitor cells suggesting the essential role of HDACIs in the regulation of AChE expression. For behavioral analysis, we injected PBS or donepezil (0.3 mg/kg) intraperitoneally to control and VPA mice once daily from postnatal day 14 all throughout the experiment. Subchronic treatment of donepezil improved sociability and prevented repetitive behavior and hyperactivity of VPA-treated mice offspring. Taken together, these results provide evidence that dysregulation of ACh system represented by the up-regulation of AChE may serve as an effective pharmacological therapeutic target against autistic behaviors in VPA animal model of ASD, which should be subjected for further investigation to verify the clinical relevance.
A culture-based colony counting method is the most widely used analytical technique for monitoring bioaerosols in both indoor and outdoor environments. However, this method requires several days for ...colony formation. In this study, our goal was fast monitoring (Sampling: 3 min, Detection: < 1 min) of indoor bioaerosol concentrations with ATP bioluminescence assay using a bioaerosol sampler. For this purpose, a novel hand-held electrostatic rod-type sampler (110 mm wide, 115 mm long, and 200 mm tall) was developed and used with a commercial luminometer, which employs the Adenosine triphosphate (ATP) bioluminescence method. The sampler consisted of a wire-rod type charger and a cylindrical collector, and was operated with an applied voltage of 4.5 kV and a sampling flow rate of 150.7 lpm. Its performance was tested using Staphylococcus epidermidis which was aerosolized with an atomizer. Bioaerosol concentrations were measured using ATP bioluminescence method with our sampler and compared with the culture-based method using Andersen cascade impactor under controlled laboratory conditions. Indoor bioaerosol concentrations were also measured using both methods in various indoor environments. A linear correlation was obtained between both methods in lab-tests and field-tests. Our proposed sampler with ATP bioluminescence method may be effective for fast monitoring of indoor bioaerosol concentrations.
An explicit analytical model for long-channel double-gate junctionless transistors is presented in each operation mode: 1) full depletion; 2) partial depletion; and 3) accumulation. The proposed ...model calculates potentials, electric fields, mobile charges, and drain current without any implicit function or special functions. The results obtained with the proposed model agree well with the results obtained with a 2-D technology computer-aided design simulation in all modes of operation and for various device structures. Furthermore, a physical insight is provided into reducing variability using the threshold voltage model.
Imbalance in excitatory/inhibitory signal in the brain has been proposed as one of the main pathological features in autism spectrum disorders, although the underlying cellular and molecular ...mechanism is unclear yet. Because excitatory/inhibitory imbalance can be induced by aberration in glutamatergic/GABAergic neuronal differentiation, we investigated the mechanism of dysregulated neuronal differentiation between excitatory and inhibitory neurons in the embryonic and postnatal brain of prenatally valproic acid-exposed rat offspring, which is often used as an animal model of autism spectrum disorders. Transcription factor Pax6, implicated in glutamatergic neuronal differentiation, was transiently increased in embryonic cortex by valproate exposure, which resulted in the increased expression of glutamatergic proteins in postnatal brain of offspring. Chromatin immunoprecipitation showed increased acetylated histone binding on
Pax6
promoter region, which may underlie the transcriptional up-regulation of Pax6. Other histone deacetylase (HDAC) inhibitors including TSA and SB but not valpromide, which is devoid of HDAC inhibitor activity, induced Pax6 up-regulation. Silencing Pax6 expression in cultured rat primary neural progenitor cells demonstrated that up-regulation of Pax6 plays an essential role in valproate-induced glutamatergic differentiation. Blocking glutamatergic transmission with MK-801 or memantine treatment, and to a lesser extent with MPEP treatment, reversed the impaired social behaviors and seizure susceptibility of prenatally valproate-exposed offspring. Together, environmental factors may contribute to the imbalance in excitatory/inhibitory neuronal activity in autistic brain by altering expression of transcription factors governing glutamatergic/GABAergic differentiation during fetal neural development, in conjunction with the genetic preload.
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