Modified cellular automaton simulation of metal additive manufacturing

Metal additive manufacturing (AM) technologies are attracting attentions not only as a fabrication process of complicated threedimensional parts but also as microstructure controlling processes. In powder bed fusion (PBF)-type AM, crystallographic texture can be controlled by scanning strategies of energy beam. To optimize microstructures, computer simulations for predicting microstructures play very important roles. In this work, we have developed simulation programs to explain the mechanism of the crystal orientation control. First, we simulated the shape of melt pool by analyzing the heat transfer using apparent heat conductivity when the penetration of laser beam through keyholes was taken into consideration because of the evaporation and accompanying convections. It was assumed that the primary crystal growth direction can be determined by the temperature gradient, and the crystals grow keeping the growth direction as generally recognized. The shapes of simulated melt pools agree well with experimental observations. The modified cellular automaton simulations successfully reproduced two typical textures with different preferential orientations along the building directions of (100) and (110) when the bidirectional scanning with and without a rotation of 90°, respectively, was accomplished between the layers.Kubo J., Koizumi Y., Ishimoto T., et al. Modified cellular automaton simulation of metal additive manufacturing. Materials Transactions 62, 864 (2021); https://doi.org/10.2320/matertrans.MT-M2021009

Pattern-recalling processes in quantum Hopfield networks far from saturation

As a mathematical model of associative memories, the Hopfield model was now well-established and a lot of studies to reveal the pattern-recalling process have been done from various different approaches. As well-known, a single neuron is itself an uncertain, noisy unit with a finite unnegligible error in the input-output relation. To model the situation artificially, a kind of 'heat bath' that surrounds neurons is introduced. The heat bath, which is a source of noise, is specified by the 'temperature'. Several studies concerning the pattern-recalling processes of the Hopfield model governed by the Glauber-dynamics at finite temperature were already reported. However, we might extend the 'thermal noise' to the quantum-mechanical variant. In this paper, in terms of the stochastic process of quantum-mechanical Markov chain Monte Carlo method (the quantum MCMC), we analytically derive macroscopically deterministic equations of order parameters such as 'overlap' in a quantum-mechanical variant of the Hopfield neural networks (let us call "quantum Hopfield model" or "quantum Hopfield networks"). For the case in which non-extensive number $p$ of patterns are embedded via asymmetric Hebbian connections, namely, $p/N \to 0$ for the number of neuron $N \to \infty$ ('far from saturation'), we evaluate the recalling processes for one of the built-in patterns under the influence of quantum-mechanical noise.Comment: 10 pages, 3 figures, using jpconf.cls, Proc. of Statphys-Kolkata VI

CENP-B box is required for de novo centromere chromatin assembly on human alphoid DNA

Centromere protein (CENP) B boxes, recognition sequences of CENP-B, appear at regular intervals in human centromeric α-satellite DNA (alphoid DNA). In this study, to determine whether information carried by the primary sequence of alphoid DNA is involved in assembly of functional human centromeres, we created four kinds of synthetic repetitive sequences: modified alphoid DNA with point mutations in all CENP-B boxes, resulting in loss of all CENP-B binding activity; unmodified alphoid DNA containing functional CENP-B boxes; and nonalphoid repetitive DNA sequences with or without functional CENP-B boxes. These four synthetic repetitive DNAs were introduced into cultured human cells (HT1080), and de novo centromere assembly was assessed using the mammalian artificial chromosome (MAC) formation assay. We found that both the CENP-B box and the alphoid DNA sequence are required for de novo MAC formation and assembly of functional centromere components such as CENP-A, CENP-C, and CENP-E. Using the chromatin immunoprecipitation assay, we found that direct assembly of CENP-A and CENP-B in cells with synthetic alphoid DNA required functional CENP-B boxes. To the best of our knowledge, this is the first reported evidence of a functional molecular link between a centromere-specific DNA sequence and centromeric chromatin assembly in humans

Upper limb muscle atrophy associated with in-hospital mortality and physical function impairments in mechanically ventilated critically ill adults : a two-center prospective observational study

Background: Lower limb muscle atrophy is often observed in critically ill patients. Although upper limb muscles can undergo atrophy, it remains unclear how this atrophy is associated with clinical outcomes. We hypothesized that this atrophy is associated with mortality and impairments in physical function. Methods: In this two-center prospective observational study, we included adult patients who were expected to require mechanical ventilation for > 48 h and remain in the intensive care unit (ICU) for > 5 days. We used ultrasound to evaluate the cross-sectional area of the biceps brachii on days 1, 3, 5, and 7 and upon ICU discharge along with assessment of physical functions. The primary outcome was the relationship between muscle atrophy ratio and in-hospital mortality on each measurement day, which was assessed using multivariate analysis. The secondary outcomes were the relationships between upper limb muscle atrophy and Medical Research Council (MRC) score, handgrip strength, ICU Mobility Scale (IMS) score, and Functional Status Score for the ICU (FSS-ICU). Results: Sixty-four patients (43 males; aged 70 ± 13 years) were enrolled. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was 27 (22–30), and in-hospital mortality occurred in 21 (33%) patients. The decreased cross-sectional area of the biceps brachii was not associated with in-hospital mortality on day 3 (p = 0.43) but was associated on days 5 (p = 0.01) and 7 (p < 0.01), which was confirmed after adjusting for sex, age, and APACHE II score. In 27 patients in whom physical functions were assessed, the decrease of the cross-sectional area of the biceps brachii was associated with MRC score (r = 0.47, p = 0.01), handgrip strength (r = 0.50, p = 0.01), and FSS-ICU (r = 0.56, p < 0.01), but not with IMS score (r = 0.35, p = 0.07) upon ICU discharge. Conclusions: Upper limb muscle atrophy was associated with in-hospital mortality and physical function impairments; thus, it is prudent to monitor it

扁桃体基底外側核に存在するSCOP/PHLPP1βによるマウス不安様行動の概日制御

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 多羽田 哲也, 東京大学教授 深田 吉孝, 東京大学教授 榎本 和生, 東京大学准教授 入江 直樹, 東京大学准教授 眞田 佳門University of Tokyo(東京大学

Variation in Courtship Ultrasounds of Three Ostrinia Moths with Different Sex Pheromones

Moths use ultrasounds as well as pheromones for sexual communication. In closely related moth species, variations in ultrasounds and pheromones are likely to profoundly affect mate recognition, reproductive isolation, and speciation. The European corn borer, Ostrinia nubilalis, and its Asian congeners, Ostrinia furnacalis and Ostrinia scapulalis, exhibit within-species and between-species variation in their pheromone communication. Recently, we reported ultrasound communication in O. furnacalis; however, variations in ultrasounds in the three congeners have not been addressed to date. Here we investigated features of ultrasound production and hearing in O. nubilalis and O. scapulalis, and compared them with those of O. furnacalis. As in O. furnacalis, males of O. nubilalis and O. scapulalis produced ultrasounds during courtship by rubbing specialized scales on the wings against scales on the thorax. The covering of these scales with nail polish muffled the sounds and significantly reduced mating success in O. nubilalis, showing the importance of ultrasound signaling in mating. The ultrasounds produced by O. nubilalis and O. scapulalis were similar, consisting of long trains of pairs of pulses with a main energy at 40 kHz, but distinctly different from the ultrasound produced by O. furnacalis, consisting of groups of pulses peaking at 50 kHz and with substantially more energy up to 80 kHz. Despite overall similarities, temporal features and patterns of amplitude modulation differed significantly among the geographic populations of O. nubilalis and O. scapulalis, which differed in pheromone type. In contrast, no significant difference in hearing was found among the three species with regard to the most sensitive frequencies and hearing threshold levels. The patterns of variations in the songs and pheromones well reflected those of the phylogenetic relationships, implying that ultrasound and pheromone communications have diverged concordantly. Our results suggest that concordant evolution in sexual signals such as courtship ultrasounds and sex pheromones occurs in moths

Continuous decrease in serum brain-derived neurotrophic factor (BDNF) levels in a neuropsychiatric syndrome of systemic lupus erythematosus patient with organic brain changes

In the present study, the authors reported on a case in neuropsychiatric syndromes of systemic lupus erythematosus (NPSLE) with irreversible organic brain changes. The authors also longitudinally investigated serum brain-derived neurotrophic factor (BDNF) levels in the patient. We found that serum BDNF levels in the NPSLE patient with irreversible organic brain change were consistently low, independent of the severity of psychiatric symptoms. Thus, the longitudinal measurement of serum BDNF levels might be useful in predicting the prognosis of NPSLE

Use of FDG-PET in Radiation Treatment Planning for Thoracic Cancers

Radiotherapy plays an important role in the treatment for thoracic cancers. Accurate diagnosis is essential to correctly perform curative radiotherapy. Tumor delineation is also important to prevent geographic misses in radiotherapy planning. Currently, planning is based on computed tomography (CT) imaging when radiation oncologists manually contour the tumor, and this practice often induces interobserver variability. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been reported to enable accurate staging and detect tumor extension in several thoracic cancers, such as lung cancer and esophageal cancer. FDG-PET imaging has many potential advantages in radiotherapy planning for these cancers, because it can add biological information to conventional anatomical images and decrease the inter-observer variability. FDG-PET improves radiotherapy volume and enables dose escalation without causing severe side effects, especially in lung cancer patients. The main advantage of FDG-PET for esophageal cancer patients is the detection of unrecognized lymph node or distal metastases. However, automatic delineation by FDG-PET is still controversial in these tumors, despite the initial expectations. We will review the role of FDG-PET in radiotherapy for thoracic cancers, including lung cancer and esophageal cancer

Osteoporosis Changes Collagen/Apatite Orientation and Young’s Modulus in Vertebral Cortical Bone of Rat

This study revealed the distinguished changes of preferential orientation of collagen and apatite and Young’s modulus in two different types of osteoporotic bones compared with the normal bone. Little is known about the bone material properties of osteoporotic bones; therefore, we aimed to assess material properties in osteoporotic bones. 66 female Sprague–Dawley rats were used. We analyzed the volumetric bone mineral density, collagen/apatite orientation, and Young’s modulus of fifth lumbar vertebral cortex for osteoporotic rats caused by ovariectomy (OVX), administration of low calcium and phosphate content (LCaP) diet, and their combination (OVX + LCaP), as well as sham-operated control. Osteocyte conditions were assessed by hematoxylin and eosin and immunohistochemical (matrix extracellular phosphoglycoprotein (MEPE) and dentin matrix protein 1 (DMP1)) staining. All osteoporotic animals showed bone loss compared with the sham-operated control. OVX improved craniocaudal Young’s modulus by enhancing collagen/apatite orientation along the craniocaudal axis, likely in response to the elevated stress due to osteoporotic bone loss. Conversely, LCaP-fed animals showed either significant bone loss or degraded collagen/apatite orientation and Young’s modulus. Osteocytes in LCaP and OVX + LCaP groups showed atypical appearance and MEPE- and DMP1-negative phenotype, whereas those in the OVX group showed similarity with osteocytes in the control group. This suggests that osteocytes are possibly involved in the osteoporotic changes in collagen/apatite orientation and Young’s modulus. This study is the first to demonstrate that osteoporosis changes collagen/apatite orientation and Young’s modulus in an opposite manner depending on the cause of osteoporosis in spite of common bone loss.Ozasa R., Ishimoto T., Miyabe S., et al. Osteoporosis Changes Collagen/Apatite Orientation and Young’s Modulus in Vertebral Cortical Bone of Rat. Calcified Tissue International, 104, 4, 449. https://doi.org/10.1007/s00223-018-0508-z

Quantitative ultrasound (QUS) axial transmission method reflects anisotropy in micro-arrangement of apatite crystallites in human long bones: A study with 3-MHz-frequency ultrasound

Anisotropic arrangement of apatite crystallites, i.e., preferential orientation of the apatite c-axis, is known to be an important bone quality parameter that governs the mechanical properties. However, noninvasive evaluation of apatite orientation has not been achieved to date. The present paper reports the potential of quantitative ultrasound (QUS) for noninvasive evaluation of the degree of apatite orientation in human bone for the first time. A novel QUS instrument for implementation of the axial transmission (AT) method is developed, so as to achieve precise measurement of the speed of sound (SOS) in the cortex (cSOS) of human long bone. The advantages of our QUS instrument are the following: (i) it is equipped with a cortical bone surface-morphology detection system to correct the ultrasound transmission distance, which should be necessary for AT measurement of long bone covered by soft tissue of non-uniform thickness; and (ii) ultrasound with a relatively high frequency of 3 MHz is employed, enabling thickness-independent cSOS measurement even for the thin cortex by preventing guide wave generation. The reliability of the proposed AT measurement system is confirmed through comparison with the well-established direct transmission (DT) method. The cSOS in human long bone is found to exhibit considerable direction-dependent anisotropy; the axial cSOS (3870 ± 66 m/s) is the highest, followed by the tangential (3411 ± 94 m/s) and radial (3320 ± 85 m/s) cSOSs. The degree of apatite orientation exhibits the same order, despite the unchanged bone mineral density. Multiple regression analysis reveals that the cSOS of human long bone strongly reflects the apatite orientation. The cSOS determined by the AT method is positively correlated with that determined by the DT method and sensitively reflects the apatite orientation variation, indicating the validity of the AT instrument developed in this study. Our instrument will be beneficial for noninvasive evaluation of the material integrity of the human long-bone cortex, as determined by apatite c-axis orientation along the axial direction.Ishimoto T., Suetoshi R., Cretin D., et al. Quantitative ultrasound (QUS) axial transmission method reflects anisotropy in micro-arrangement of apatite crystallites in human long bones: A study with 3-MHz-frequency ultrasound. Bone, 127, 82. https://doi.org/10.1016/j.bone.2019.05.034