Estimation of Average Grain Size from Microstructure Image Using a Convolutional Neural Network.

In this study, the average grain size was evaluated from a microstructure image using a convolutional neural network. Since the grain size in a microstructure image can be directly measured and verified in the original image, unlike the chemical composition or mechanical properties of material, it is more appropriate to validate the training results quantitatively. An analysis of microstructure images, such as grain size, can be performed manually or using image analysis software; however, it is expected that the analysis would be simpler and faster with machine learning. Microstructure images were created using a phase-field simulation, and machine learning was carried out with a convolutional neural network model. The relationship between the microstructure image and the average grain size was not judged by classification, as the goal was to have different results for each microstructure using regression. The results showed high accuracy within the training range. The average grain sizes of experimental images with explicit grain boundary were well estimated by the network. The mid-layer image was analyzed to examine how the network understood the input microstructure image. The network seemed to recognize the curvatures of the grain boundaries and estimate the average grain size from these curvatures.

Closure of oroantral fistula: a review of local flap techniques.

Oroantral fistula (OAF), also termed oroantral communication, is an abnormal condition in which there is a communicating tract between the maxillary sinus and the oral cavity. The most common causes of this pathological communication are known to be dental implant surgery and extraction of posterior maxillary teeth. The purpose of this article is to describe OAF; introduce the approach algorithm for the treatment of OAF; and review the fundamental surgical techniques for fistula closure with their advantages and disadvantages. The author included a thorough review of the previous studies acquired from the PubMed database. Based on this review, this article presents cases of OAF patients treated with buccal flap, buccal fat pad (BFP), and palatal rotational flap techniques.

The Neck and Posterior Fossa Combined Penetrating Injury: A Case Report.

Here we report a case of penetrating neck injury to the posterior fossa that was shown, using high-resolution computed tomography (HRCT) and digital subtraction angiography (DSA), to involve no vascular injury. A 54-year-old man was brought to the emergency department after a penetrating injury to the left side of the posterior neck and occipital area with a knife. He was in an intoxicated state and could not communicate readily. On initial examination, his vital signs were stable and there was no active bleeding from the penetrating site. Because of concern about possible injury to adjacent vessels, we performed HRCT and DSA sequentially, and identified that the blade of the knife had just missed the arteriovenous structures in the neck and posterior fossa. The patient was then transferred to the operating room where the knife was gently removed. Further careful exploration was performed through the penetrating wound, and we confirmed that there were no major injuries to the vessels and neural structures. Postoperative computed tomography revealed that there was minimal hemorrhage in the left cerebellar hemisphere. The patient made a full recovery without any neurologic deficit. In this case, HRCT is a suitable tool for the initial overall evaluation. For the evaluation of vascular injury, DSA can be a specific and accurate tool. Mandatory exploration widely used for penetrating injuries. After careful preoperative evaluation and interpretation, simple withdrawal of material can be a choice of treatment.

High-durable AgNi nanomesh film for a transparent conducting electrode.

Uniform metal nanomesh structures are promising candidates that may replace of indium-tin oxide (ITO) in transparent conducting electrodes (TCEs). However, the durability of the uniform metal mesh has not yet been studied. For this reason, a comparative analysis of the durability of TCEs based on pure Ag and AgNi nanomesh, which are fabricated by using simple transfer printing, is performed. The AgNi nanomesh shows high long-term stability to oxidation, heat, and chemicals compared with that of pure Ag nanomesh. This is because of nickel in the AgNi nanomesh. Furthermore, the AgNi nanomesh shows strong adhesion to a transparent substrate and good stability after repeated bending.

Emission rates of air pollutants from portable gas ranges and nitrogen dioxide exposure assessment in restaurants.

It is important to characterize the emission of air pollutants and suggest an optimum ventilation rate, because the use of portable gas ranges is widespread in houses and restaurants in Korea. Source emission tests were conducted to characterize the emissions of nitrogen oxide (NOx = NO + NO2), carbon monoxide (CO), carbon dioxide (CO2), formaldehyde (HCHO) and total volatile organic compounds (TVOCs) from portable gas ranges in steady-state using a well-mixed chamber. The ranges of emission rates of air pollutants from portable gas ranges were 0.55-0.94 mg/h for NO, 0.35-1.08 mg/h for NO2, 1.21-1.63 mg/h for NOx 1.39-4.21 mg/h for CO, 2430-2970 mg/h for CO2 and 0-0.12 mg/h for TVOCs. The required mean and maximum ventilation rates to control the air pollutants from portable gas ranges was 2.70 m3/h and 3.13 m3/h on the basis of the NO2 emission rate, respectively. The mean concentrations of food service worker and customer exposures to NO2 by use of portable gas ranges in restaurants were 48.2 +/- 21.5 ppb and 64.7 +/- 31.5 ppb, respectively.

Dissemination of transferable AmpC-type beta-lactamase (CMY-10) in a Korean hospital.

To determine dissemination and genotype of AmpC beta-lactamases and an extended-spectrum beta-lactamase among clinical isolates of Enterobacteriaceae, we performed antibiotic susceptibility testing, pI determination, induction test, plasmid profiles, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing. Among the 51 clinical isolates collected from a university hospital in Korea, six isolates were resistant to cephamycins. All six isolates produced a plasmid-encoded AmpC-type beta-lactamase, CMY-10. Five strains also produced one or more other beta-lactamases: SHV-12, an extended-spectrum beta-lactamase (five isolates); TEM-1, a class A beta-lactamase (two isolates); and a chromosomal AmpC beta-lactamase (one isolate, a strain of Enterobacter aerogenes, which produced all four of the beta-lactamases that were identified). One of six isolates produced only CMY-10. ERIC-PCR analysis revealed that dissemination of CMY-10 and SHV-12 was due to a clonal outbreak of a resistant strain and to the interspecies spread of resistance to cephamycins and broad-spectrum beta-lactams in Korea. CMY-10 beta-lactamase genes that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized from six clinical isolates. A sequence identical to the common regions in In6, In7, and a novel integron from pSAL-1 was found upstream from blaCMY-10 gene at nucleotides 1-71. A total of 15 nucleotides (I-15) or 18 nucleotides (I-18) between position 71 and 72 were inserted into the blaCMY-10 gene. The blaCMY-10 gene might be inserted into a sul1-type complex integron by I-15 or I-18.