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• Mass transfer across a gas–liquid interface of acoustic cavitation is investigated. • Time-averaged Sherwood number is decreased with sound pressure amplitude. • Time-averaged Sherwood number can be negative value due to area and shell effect. • The instantaneous Sherwood number is varied in the range of O (101) ∼ O (102). In the present study, mass transfer across a gas–liquid interface of acoustic cavitation bubble is numerically investigated. The volume of fluid (VOF) method coupled with a continuous species transfer model is used to simulate the bubble dynamic behavior and mass transfer across the gas–liquid interface. Chemical species are transferred repeatedly between the liquid and gas phases in accordance with the bubble oscillation, and the chemical species are transferred into the bubble during an expansion phase, and to the outside of bubble during a compression phase. Time-averaged Sherwood number is decreased with an amplitude of sound pressure due to area effect and shell effect , and its value becomes negative at high pressure amplitude. Meanwhile, the instantaneous Sherwood number is largely varied in accordance with the bubble oscillation, and its magnitude becomes O (101) ∼ O (102). [ABSTRACT FROM AUTHOR]

Recent regenerative studies using human pluripotent stem cells (hPSCs) have developed multiple kidney-lineage cells and organoids. However, to further form functional segments of the kidney, interactions of epithelial and interstitial cells are required. Here we describe a selective differentiation of renal interstitial progenitor-like cells (IPLCs) from human induced pluripotent stem cells (hiPSCs) by modifying our previous induction method for nephron progenitor cells (NPCs) and analyzing mouse embryonic interstitial progenitor cell (IPC) development. Our IPLCs combined with hiPSC-derived NPCs and nephric duct cells form nephrogenic niche- and mesangium-like structures in vitro. Furthermore, we successfully induce hiPSC-derived IPLCs to differentiate into mesangial and erythropoietin-producing cell lineages in vitro by screening differentiation-inducing factors and confirm that p38 MAPK, hypoxia, and VEGF signaling pathways are involved in the differentiation of mesangial-lineage cells. These findings indicate that our IPC-lineage induction method contributes to kidney regeneration and developmental research. [Display omitted] • A selective induction method for renal IPC-like cells from hiPSCs was established • Co-culture of hiPSC-derived IPLCs and NPCs form mesangium-like structures in vitro • hiPSC-derived IPLCs develop mesangial and EPO-producing cell lineages in vitro • Crucial roles of p38 MAPK signaling in mesangial-lineage development were revealed Tsujimoto et al. establish the selective induction of renal interstitial progenitor-like cells (IPLCs) from hiPSCs. These IPLCs form mesangium-like structures when combined with hiPSC-derived nephron progenitor cells and selectively differentiate into mesangial and EPO-producing cells in vitro , revealing crucial roles of p38 MAPK, VEGF, and hedgehog signaling in interstitial development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Largest reactor pressure vessel steel embrittlement database available includes test reactor and surveillance data. • Machine learning model for accurate prediction of embrittlement with low errors and large applicability domain. • Well-calibrated uncertainty estimates for informing uncertainty quantification on new predictions. • Use machine learning model to assess physical trends, construct embrittlement curves, and predict alloy life extension behavior. An essential aspect of extending safe operation of the world's active nuclear reactors is understanding and predicting the embrittlement that occurs in the steels that make up the Reactor pressure vessel (RPV). In this work we integrate state of the art machine learning methods using ensembles of neural networks with unprecedented data collection and integration to develop a new model for RPV steel embrittlement. The new model has multiple improvements over previous machine learning and hand-tuned efforts, including greater accuracy (e.g., at high-fluence relevant for extending the life of present reactors), wider domain of applicability (e.g., including a wide-range of compositions), uncertainty quantification, and online accessibility for easy use by the community. These improvements provide a model with significant new capabilities, including the ability to easily and accurately explore compositions, flux, and fluence effects on RPV steel embrittlement for the first time. Furthermore, our detailed comparisons show our approach improves on the leading American Society for Testing and Materials (ASTM) E900-15 standard model for RPV embrittlement on every metric we assessed, demonstrating the efficacy of machine learning approaches for this type of highly demanding materials property prediction. [ABSTRACT FROM AUTHOR]

• Bubble fragmentation in a stirred vessel is categorized into three types: collision with a blade, boundary layer ahead of blade, and vortex-induced viscous shear stress. • Six-types fragmentation was observed according to the interaction between trailing vortices and bubble. • The bubble is fragmented by a single trailing vortex according to the two mechanisms: a trailing vortex cuts-off and a rotational flow of trailing vortex. • The bubble can be fragmented by several trailing vortices at the gap between them. We investigated the mechanism of single-bubble fragmentation during mechanical stirring under different trailing vortex conditions. Experiments and numerical simulations using the LES-VOF method were carried out under different bubble sizes and locations of bubble injection. We found that the following three phenomena can cause bubble fragmentation: collision with impeller blade; shear stress in the boundary layer ahead of the impeller blade; and interaction between trailing vortices and the bubble. In the last case, the mechanism of fragmentation can be categorized into six types, which are determined by the relationship between the bubble behavior and the trailing vortices. Thus, we clarified the relationship between trailing vortices and bubble fragmentation for the first time in a stirred vessel. [ABSTRACT FROM AUTHOR]

Several authors have reported the occurrence of extraforaminal L5 nerve root compression between lumbosacral transitional vertebrae (LSTV) and sacral ala, but reports on a lesion caused by an intervertebral osteophyte on the ventral and contralateral side of a unilateral abnormality by LSTV are hardly available. A 67-year-old woman presented with pain along the distribution of the L5 nerve root; straight leg raise test, femoral nerve stretch test, and Kemp test were positive on the left. Following plain radiographs, computerized tomography, magnetic resonance imaging, and selective nerve root block, an osteophyte bridging the L5 and S1 vertebral bodies in the ventral side was identified compressing the L5 nerve root. On account of resistance to conservative therapy and the delicate position of the lesion, surgical treatment was performed by an anterior decompression. Subsequently, the patient attained adequate relief from pain and could walk normally. We herein present a very rare case of extraforaminal L5 nerve root compression caused by an intervertebral osteophyte on the ventral and contralateral side of a unilateral abnormality by LSTV, which was managed by anterior decompression. [ABSTRACT FROM AUTHOR]

Abstract A series of Fe-3 to 18 at.% Cr binary ferritic alloys were neutron irradiated side by side, in the Advanced Test Reactor (ATR) at a temperature of ∼320 °C to a dose of ∼1.8 dpa. Three types of features that form under irradiation are relevant: (i) solute clusters; (ii) α′ precipitates; and, (iii) dislocation loops. The size and number density of the precipitates and loops were measured by transmission electron microscopy (TEM) and compared to previous atom probe tomography (APT) observations. The loop density systematically decreases with increasing Cr, while the number of α′ precipitates increase at 9Cr and above. A major objective of this work is to estimate the dispersed barrier obstacle strength factors (α j) for loops, clusters and α′ precipitates, based on the combined microstructural observations and corresponding irradiation hardening measurements. Standard dispersed barrier-hardening models and computationally derived superposition rules were least square fit to determine the α j. The optimized hardening predictions are in very good agreement with experiment if mixed linear sum and root square sum superposition rules are used. Five increments of 168 h isochronal anneals of the 6Cr alloy between 300 and 400 °C coarsened the loops, while 300 h anneals of the 18Cr at 500 and 600 °C coarsened and dissolved the α′ precipitates, respectively, consistent with the Fe-Cr phase diagram. [ABSTRACT FROM AUTHOR]

Highlights • Bubbles move behind the impeller blade due to pressure distribution. • Most bubbles in an unbaffled stirred vessel are fragmented in the trailing vortices. • The fragmented bubbles are transported by the trailing vortices, the core of which traps the bubble. • Smaller and more complicated bubbles are generated with increasing the impeller rotation rate. • More bubbles are agglomerated near the shaft with increasing the impeller rotation rate due to pressure distribution. Abstract The present study investigated the mechanism of small bubble breakup in an unbaffled vessel stirred by a 4-blade paddle impeller. Bubbles were injected underneath the rotating blades. Numerical simulation and experimental observations were performed to investigate the related phenomena. The Volume of Fluid (VOF) method was utilized to simulate a gas-liquid multiphase flow. The injected bubbles were broken behind the impeller blade, where they were transported due to a decreasing pressure gradient caused by the impeller rotation. At the behind of the blade, bubbles were elongated and fragmented due to the trailing vortices developing from the rear surface of blade. The fragmented bubbles were entrapped at the cores of trailing vortices, and then floated up in the space where the trailing vortices became weak. The size of the broken bubbles was dependent on the impeller rotation rate. [ABSTRACT FROM AUTHOR]

Introduction Reports of hypertrophic spinal pachymeningitis associated with human T-cell lymphotrophic virus-1 (HTLV-1) infection and Sjogren’s syndrome in the English literature are still very rare. Presentation of case We hereby present a case of a 78-year-old female with a history of lower extremity weakness after a fall, which fully resolved after conservative treatment. However, the symptoms recurred 4 years later, and the patient became unable to walk. The patient had no superficial or deep sensation below the level of T9, and she also had urinary retention. Magnetic resonance imaging showed that hypertrophic dura mater was compressing the spinal cord from T2 to T10. Blood testing revealed increased anti-HTLV-1 antibody, rheumatoid factor, elevation of anti-SS-A antibody and antinuclear antibody. The cerebrospinal fluid contained markedly elevated levels of total protein and cell numbers. Biopsy of the labial gland of the lip revealed chronic sialadenitis. Discussion In collaboration with a neurologist, we diagnosed this patient with hypertrophic spinal pachymeningitis associated with HTLV-1 infection and Sjogren’s syndrome. We performed laminectomy at the affected spinal levels, resected the thickened dura, and maintained the patient on steroid therapy. The patient attained a marked recovery; she could walk with a cane and her urinary retention was improved. Conclusion For the management of HSP associated with HTLV-1 and SS, we recommend surgical decompression with subsequent prolonged steroid therapy and prolonged close monitoring to achieve a good long-term outcome. [ABSTRACT FROM AUTHOR]

Summary The in vitro derivation and propagation of spermatogonial stem cells (SSCs) from pluripotent stem cells (PSCs) is a key goal in reproductive science. We show here that when aggregated with embryonic testicular somatic cells (reconstituted testes), primordial germ cell-like cells (PGCLCs) induced from mouse embryonic stem cells differentiate into spermatogonia-like cells in vitro and are expandable as cells that resemble germline stem cells (GSCs), a primary cell line with SSC activity. Remarkably, GSC-like cells (GSCLCs), but not PGCLCs, colonize adult testes and, albeit less effectively than GSCs, contribute to spermatogenesis and fertile offspring. Whole-genome analyses reveal that GSCLCs exhibit aberrant methylation at vulnerable regulatory elements, including those critical for spermatogenesis, which may restrain their spermatogenic potential. Our study establishes a strategy for the in vitro derivation of SSC activity from PSCs, which, we propose, relies on faithful epigenomic regulation. [ABSTRACT FROM AUTHOR]

Recent trends in the aluminum industry toward increasing the recycling rate of aluminum alloys have led to difficulties in controlling the formation of intermetallic compounds (IMCs). The up-to-date investigations have revealed that ultrasonic irradiation is a promising tool to refine and modify the intermetallic compounds formed in the melt before or during casting, and the reported mechanisms include ultrasound-assisted nucleation and fragmentation of compounds. This work presents results concerning the modification effect of ultrasound on model Al 3 Zr compounds with emphasis on the effect of vibration amplitudes. The results reveal that needle-like Al 3 Zr compounds can be significantly modified to thicker shape when amplitude increases from 38 µm to 48 µm, and then change to more rounded shape with the further increase of amplitude. Theoretical consideration and numerical simulation show that in addition to the above-mentioned mechanisms, cavitation-induced heat generation and mircrojet-driven mass transfer are also of prime importance in controlling the morphology and growth of IMCs. • A wide range of ultrasound vibration amplitude is examined. • Needle-like Al 3 Zr compounds can be significantly modified to more rounded shape when amplitude increases. • Behavior of cavitation bubble near compound particle is simulated numerically. • Cavitation-induced heat generation and microjet-driven mass transfer play a prominent role in controlling the morphology and growth of primary Al 3 Zr compounds. [ABSTRACT FROM AUTHOR]

Riparian vegetation exerts significant effects on the flow structure and the geomorphology of rivers. While it provides a rich wildlife habitat as well as a protection from bank erosion, vegetation can increase the risk of flood inundation by reducing the carrying capacity of flood. A proper balance between flood control and riparian eco-diversity is therefore indispensable for better riparian management. In the present study, the effect of vegetation configuration on turbulent flows in a rectangular open channel, especially on the resulting flow resistance, has been investigated both experimentally and numerically. The laboratory experiments are conducted for two types of vegetation configurations, where vegetation is established either continuously or in a discrete way along the centerline of the flume. A regular array of emergent circular cylinders of diameter 3 mm with the stem-to-stem centerline spacing of 3 cm is used as a laboratory model for vegetation. The applicability of a basic large-eddy simulation (LES) method together with a canopy model is critically examined against the experimental data. A great agreement between the present three-dimensional LES results and the experimental data is achieved in the continuous case. On the other hand, the LES is found to fail in reproducing the streamwise variation of the mean flow structures accurately in the discrete case. This failure is mainly due to the arrangement of a uniform distribution of the drag coefficient required in the canopy model. The LES is applied to flows with a wide variety of vegetation configurations to examine the relationship between the presence of vegetation and the resulting flow resistance. It is found that, in most cases, the flow resistance solely depends on the total volume of vegetation, irrespective of the configuration details in the streamwise direction. However, shifting vegetation toward the side wall achieves a considerable drag reduction. This is partly because the primary velocity is decreased with approaching the side wall and partly because the lateral mixing is suppressed by the presence of the side wall. [ABSTRACT FROM AUTHOR]

Formation of a high density of Mn–Ni–Si nanoscale precipitates in irradiated Cu-free and Cu-bearing reactor pressure vessel steels could lead to severe unexpected embrittlement. Models long ago predicted that these precipitates, which are not treated in current embrittlement prediction models, would emerge only at high fluence. However, the mechanisms and variables that control Mn–Ni–Si precipitate formation, and their detailed characteristics, have not been well understood. High flux irradiations of six steels with systematic variations in Cu and Ni contents were carried out at ∼295 °C to high and very high neutron fluences of ∼1.3 × 10 20 and ∼1.1 × 10 21 n cm −2 . Atom probe tomography shows that significant mole fractions of Mn–Ni–Si-dominated precipitates form in the Cu-bearing steels at ∼1.3 × 10 20 n cm −2 , while they are only beginning to develop in Cu-free steels. However, large mole fractions of these precipitates, far in excess of those found in previous studies, are observed at 1.1 × 10 21 n cm −2 at all Cu contents. At the highest fluence, the precipitate mole fractions primarily depend on the alloy Ni, rather than Cu, content. The Mn–Ni–Si precipitates lead to very large increases in measured hardness, corresponding to yield strength elevations of up to almost 700 MPa. [ABSTRACT FROM AUTHOR]

The resistance to transcription factor-mediated reprogramming into pluripotent stem cells is one of the distinctive features of cancer cells. Here we dissect the profiles of reprogramming factor binding and the subsequent transcriptional response in cancer cells to reveal its underlying mechanisms. Using clear cell sarcomas (CCSs), we show that the driver oncogene EWS/ATF1 misdirects the reprogramming factors to cancer-specific enhancers and thereby impairs the transcriptional response toward pluripotency that is otherwise provoked. Sensitization to the reprogramming cue is observed in other cancer types when the corresponding oncogenic signals are pharmacologically inhibited. Exploiting this oncogene dependence of the transcriptional "stiffness," we identify mTOR signaling pathways downstream of EWS/ATF1 and discover that inhibiting mTOR activity substantially attenuates the propagation of CCS cells in vitro and in vivo. Our results demonstrate that the early transcriptional response to cell fate perturbations can be a faithful readout to identify effective therapeutics targets in cancer cells. [Display omitted] • Driver oncogenic signals impede transcriptional responses to reprogramming TFs • Reprogramming TFs are misdirected by oncogenic signals to bind cancer cell enhancers • A screening platform based on the oncogene dependence of the impediment is developed • The screening identifies mTOR signaling as a therapeutic target in CCS In general, cancer cells are resistant to reprogramming. Ito et al. show that this is due to misdirection of reprogramming factors by oncogenic driver signals. Exploiting this finding, they established a novel screening platform that identifies mTOR signaling as a potential therapeutic target in CCS. [ABSTRACT FROM AUTHOR]