Low energy Si+, SiCH5+, or C+ beam injections to silicon substrates during chemical vapor deposition with dimethylsilane.

We found that the atomic-concentration-ratio of carbon to silicon (C/Si ratio) in silicon carbide (SiC) films formed by thermal chemical vapor deposition (CVD) was much greater than 1 when the source gas for CVD was dimethylsilane (DMS). Thus, we tried to change carbon-inclusion levels in the film by injecting some ion beams into a depositing SiC film during the CVD process with DMS. Three ion beams, i.e., Si+, SiCH5+, or C+ ions were injected to depositing SiC films. The energy of Si+, SiCH5+, and C+ ions was 110 eV. The temperature of the substrate was 800 °C. X-ray diffraction of the deposited films showed that 3C-SiC was included in all three samples. X-ray photoelectron spectroscopy (XPS) showed that the C/Si ratio of the obtained SiC film increased significantly following the Si+ or C+ ion beam irradiations. The XPS measurements also showed that the C/Si ratio of the SiC film obtained by injecting SiCH5+ beam during thermal CVD with DMS was lower than that of the SiC film formed by thermal CVD with DMS alone.

Feasibility and learning curve for robotic surgery in a small hospital: A retrospective cohort study.

Robotic surgery rates, typified by the use of the da Vinci Surgical System, have increased in recent years. However, robotic surgery is mostly performed in large hospitals and has not been fully implemented in small hospitals. Therefore, we aimed to verify the feasibility of robotic surgery in small hospitals and verify the number of cases in which perioperative preparation for robotic surgery is stable by creating a learning curve in small hospitals. Forty robot-assisted rectal cancer surgeries performed in large and small hospitals by a surgeon with extensive experience in robotic surgery were validated. Draping and docking times were recorded as perioperative preparation times. Unexpected surgical interruptions, intraoperative adverse events, conversion to laparoscopic or open surgery, and postoperative complications were recorded. Cumulative sum analysis was used to derive the learning curve for perioperative preparation time. Draping times were significantly longer in the small hospital group (7 vs 10 minutes, P = .0002), while docking times were not significantly different (12 vs 13 minutes, P = .098). Surgical interruptions, intraoperative adverse events, and conversions were not observed in either group. There were no significant differences in the incidence of severe complications (25% [5/20] vs 5% [1/20], P = .184). In the small hospital group, phase I of the draping learning curve was completed in 4 cases, while phase I of the docking learning curve was completed in 7 cases. Robotic surgery is feasible for small hospitals, and the preoperative preparation time required for robotic surgery stabilizes relatively early.

Low-energy Ar+ ion-beam-induced chemical vapor deposition of silicon dioxide films using tetraethyl orthosilicate.

This study was conducted to determine whether the simultaneous injections of Ar+ ions and tetraethyl orthosilicate (TEOS) to a substrate are able to fabricate a film on the substrate. The Ar+ ion energy was 100 eV. After the injections, we found a film deposited on the substrate. Following the analyses of the film with X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, it was found that the deposited film was silicon dioxide (SiO2). We conclude that the low-energy Ar+ ion-beam-induced deposition method using TEOS is useful for the growth of SiO2 films.

Simultaneous colonic metastasis of advanced gastric cancer: a case report.

BACKGROUND: Although distant metastasis in gastric cancer can be present at the time of the initial diagnosis, colonic metastasis is extremely rare. This report describes a case of simultaneous colonic metastasis of advanced gastric cancer. CASE PRESENTATION: The patient was a 78-year-old woman with nausea and epigastric pain. Upper gastrointestinal endoscopy revealed an advanced invasive ulcerative tumor in the lesser curvature of the stomach extending from the anterior to the middle portion. Colonoscopy revealed a 4-mm polyp-like lesion in the mid-transverse colon; therefore, a polypectomy was performed. Both gastric and colonic tumors showed poorly differentiated adenocarcinoma with signet ring cell carcinoma. After providing informed consent, the patient underwent a total gastrectomy. Histologic examination showed similar morphologic features of both gastric and colonic tumors. Immunohistochemistry staining showed that these tumor cells were positive for cytokeratin (CK) 7 and negative for CK20. CONCLUSIONS: This was an extremely rare case of simultaneous colonic metastasis of advanced gastric cancer. Because missed metastasis can result in a poorer prognosis, we propose a systemic search including colonoscopy for patients with advanced gastric cancer, especially cases involving poorly differentiated adenocarcinoma or signet ring cell carcinoma.

[A Case of Descending Colon Cancer with Distant Metastasis That Was Controlled Severe Side Effects of Chemotherapy and Achieved Long-Term CR].

A 69-year-old male patient with descending colon cancer with para-aortic lymph node metastasis underwent surgery to resect the primary tumor. After the surgery mFOLFOX6 plus panitumumab was introduced. Because 2 times drug-induced lung disease and Stevens Johnson syndrome were occurred, changes in chemotherapy regimen were required. 18 months after administration, complete response was achieved. The chemotherapy was discontinued 48 months after administration. He is alive without recurrence for 32 months after completion of treatment.

Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions.

Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field-induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices.

Changes in AMPKα and Ubiquitin Ligases in Myocyte Reverse Remodeling after Surgical Ventricular Reconstruction in rats with ischemic cardiomyopathy.

BACKGROUND: The change in myocardial protein degradation systems after ventricular unloading has been unknown. We aimed to evaluate the anti-hypertrophic protein adenosine monophosphate-activated protein kinase (AMPK) and two major protein degradation systems (ubiquitin proteasome system and autophagy) in a model of surgical ventricular reconstruction (SVR) in rats with ischemic cardiomyopathy. METHODS AND RESULTS: Rats were randomized into the following groups: sham/sham (control group), myocardial infarction (MI)/sham (sham group) and MI/SVR (SVR group), with an interval of 4 weeks. Two (early, n = 5 for each) and 28 days (late, n = 5 for each) after SVR, ventricular size, and wall stress were assessed. Myocyte area, protein expression of AMPKα and autophagy markers, and gene expression of ubiquitin ligases (Atrogin-1 and Murf-1) were evaluated in the late phase. In the early phase, left ventricular dimensions and wall stress were smaller in the SVR group than in the sham group, whereas they were comparable in the late period. Myocyte area in the SVR group was reduced to the value in the control group, while it was larger in the sham group than in the control group. Total-AMPKα, p-AMPKα, and AMPKα phosphorylation rates were higher, and Atrogin-1 and Murf-1 were lower in the SVR group than in the sham group, while the autophagy markers were not different between the groups. p-AMPKα had strong negative correlations with myocyte area, Atrogin-1, and Murf-1. CONCLUSIONS: In myocyte reverse remodeling after SVR, AMPKα phosphorylation increased in association with reduced gene expression of ubiquitin ligases.

Effects of trehalose on recurrence of remodeling after ventricular reconstruction in rats with ischemic cardiomyopathy.

Recurrence of left ventricular (LV) remodeling after surgical ventricular reconstruction (SVR) for ischemic cardiomyopathy has been reported to be partially attributed to autophagy. We aimed to examine the effects of trehalose, an autophagy inducer, on the recurrence of LV remodeling after SVR. After SVR in rats with ICM, trehalose was orally administered. The changes in LV end-diastolic dimension (LVEDD) and fractional shortening (FS) were evaluated. The activation of myocardial autophagy was also estimated by autophagy markers: microtubule-associated light chain 3 II (LC3-II) and p62; the former usually increases and the latter decreases if autophagy is activated. Significant LV reverse remodeling was observed early after SVR. On the other hand, the 28th postoperative day SVR + trehalose was associated with smaller LVEDD and better FS than SVR alone (LVEDD, P = 0.043; FS, P < 0.01). LC3-II increased comparably in both groups, while p62 was significantly lower in the SVR + trehalose group than in the SVR alone group (P < 0.01). In conclusion, trehalose attenuated the recurrence of LV remodeling and changed autophagy markers after SVR in rats with ICM. Trehalose may be a candidate for adjuvant therapy to retain the effects of SVR.

Autophagy during left ventricular redilation after ventriculoplasty: Insights from a rat model of ischemic cardiomyopathy.

OBJECTIVES: Myocardial autophagy has been recognized as an important factor in heart failure. It is not known whether changes in ventricular geometry by left ventriculoplasty influence autophagy in ischemic cardiomyopathy. We hypothesized that myocardial autophagy plays an important role in left ventricular (LV) redilation after ventriculoplasty. METHODS: Four weeks after ligation of the left anterior descending artery, ventriculoplasty or sham operation was performed. The animals were euthanized at 2 days (early) or 28 days (late) after the second operation. Ventricular autophagy was evaluated by protein expression of microtubule-associated protein light chain 3 II, an autophagosome marker. Cardiomyocyte area was assessed by histologic examination. LV function was evaluated by echocardiography. To examine the implications of autophagy, an autophagy inhibitor (3-methyladenine) was injected intraperitoneally for 3 weeks before sacrifice. RESULTS: The LV was reduced in size early and redilated late after ventriculoplasty. LV systolic function was improved early and later worsened after ventriculoplasty. Light chain 3 II expression decreased early after ventriculoplasty and increased in the late period. Myocyte area increased from the early to late stage after ventriculoplasty. Autophagic inhibition exaggerated the increased myocyte hypertrophy and LV redilation. CONCLUSIONS: In a rat model of myocardial infarction, autophagy decreased early after ventriculoplasty and increased again during LV redilation. These results provide new insights into the mechanism underlying the late failure of ventriculoplasty.

Effects of dynamic supported standing training in a patient with pusher behavior: a case report.

BACKGROUND: The effects of task-specific and voluntary exercise in upright positions for pusher behavior remain unclear. In this report, we aimed to describe the effects of dynamic supported standing training using a modified standing frame to correct the alignment in a patient with severe pusher behavior. CASE DESCRIPTION: A 76-year-old man with cardioembolic ischemic stroke demonstrated pusher behavior. The patient underwent 3 days of dynamic supported standing training using a modified standing frame. The Scale for Contraversive Pushing, the Burke Lateropulsion Scale, and the Trunk Control Test were used to assess changes. OUTCOMES: Immediate improvements in sitting balance were observed after the intervention, and the effects persisted to 8 days later. CONCLUSION: Dynamic supported standing training using a modified standing frame may improve pusher behavior with short-term training. The collapsed posture of the patient in the present case was corrected using the modified standing frame. This neutral standing position could have a positive effect on motor learning with respect to holding one's posture.

Low-energy Ar+ and N+ ion beam induced chemical vapor deposition using hexamethyldisilazane for the formation of nitrogen containing SiC and carbon containing SiN films.

We proposed an experimental methodology for producing films on substrates with an ion beam induced chemical vapor deposition (IBICVD) method using hexamethyldisilazane (HMDS) as a source material. In this study, both HMDS and ion beam were simultaneously injected onto a Si substrate. We selected Ar+ and N+ as the ion beam. The energy of the ion beam was 101 eV. Temperature of the Si substrate was set at 540 °C. After the experiments, films were found to be deposited on the substrates. The films were then analyzed by Fourier transform infrared (FTIR) spectroscopy, stylus profilometer, X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). The FTIR and XPS results showed that silicon carbide films containing small amount of nitrogen were formed when Ar+ ions were injected in conjunction with HMDS. On the other hand, in the cases of N+ ion beam irradiation, silicon nitride films involving small amount of carbon were formed. It was noted that no film deposition was observed when HMDS alone was supplied to the substrates without any ion beam injections.

Recent progress in the development of high-performance bonded magnets using rare earth-Fe compounds.

Permanent magnets, and particularly rare earth magnets such as Nd-Fe-B, have attracted much attention because of their magnetic properties. There are two well-established techniques for obtaining sintered magnets and bonded Nd-Fe-B magnets. Powder metallurgy is used to obtain high-performance anisotropic sintered magnets. To produce bonded magnets, either melt-spinning or the hydrogenation, disproportionation, desorption, and recombination process is used to produce magnet powders, which are then mixed with binders. Since the development of Nd-Fe-B magnets, several kinds of intermetallic compounds have been reported, such as Sm2Fe17Nx and Sm(Fe,M)12 (M: Ti, V, etc.). However, it is difficult to apply a liquid-phase sintering process similar to the one used for Nd-Fe-B sintered magnets in order to produce high-performance Sm-Fe-based sintered magnets because of the low decomposition temperature of the compound and the lack of a liquid grain boundary phase like that in the Nd-Fe-B system. Therefore, bonded magnets are useful in the production of bulk magnets using these Sm-Fe-based compounds. This article reviews recent progress in our work on the development of high-performance bonded magnets using Nd2Fe14B and Sm2Fe17Nx compounds.

Amine modification of calcium phosphate by low-pressure plasma for bone regeneration.

Regeneration of large bone defects caused by trauma or tumor resection remains one of the biggest challenges in orthopedic surgery. Because of the limited availability of autograft material, the use of artificial bone is prevalent; however, the primary role of currently available artificial bone is restricted to acting as a bone graft extender owing to the lack of osteogenic ability. To explore whether surface modification might enhance artificial bone functionality, in this study we applied low-pressure plasma technology as next-generation surface treatment and processing strategy to chemically (amine) modify the surface of beta-tricalcium phosphate (ß-TCP) artificial bone using a CH4/N2/He gas mixture. Plasma-treated ß-TCP exhibited significantly enhanced hydrophilicity, facilitating the deep infiltration of cells into interconnected porous ß-TCP. Additionally, cell adhesion and osteogenic differentiation on the plasma-treated artificial bone surfaces were also enhanced. Furthermore, in a rat calvarial defect model, the plasma treatment afforded high bone regeneration capacity. Together, these results suggest that amine modification of artificial bone by plasma technology can provide a high osteogenic ability and represents a promising strategy for resolving current clinical limitations regarding the use of artificial bone.

Identification of fragment ions produced by the decomposition of tetramethyltin and the production of low-energy Sn+ ion beam.

Tetramethyltin was decomposed in an ion source and the fragment ions produced were identified using a low-energy mass-selected ion beam machine. Dominant fragment ions were found to be H+, CH2+, and Sn+. Subsequently, fragment ions were mass-selected. The mass spectrum of the selected ions indicated that only a single peak appeared at the mass number of 120 u, being suggestive of the presence of 120Sn+ ions. The ion energy was set at the range of 20-100 eV. The Sn+ ion beam was irradiated to a Si substrate, and a film was then found deposited on the substrate after the ion beam irradiation. An X-ray diffraction measurement showed that the film obtained was metallic Sn. Then, the Sn+ ion beam was irradiated to a quartz crystal microbalance substrate. We found that most of the irradiated Sn+ ions were adhered to the substrate, at the ion energy levels of 25 and 58 eV, producing the Sn film, whereas a 107 eV Sn+ beam caused a significant proportion of Sn atoms in the film to detach from the substrate, probably due to sputtering.

Creation of magnetic skyrmions by surface acoustic waves.

Non-collinear and non-coplanar spin textures, such as chiral domain walls1 and helical or triangular spin structures2,3, bring about diverse functionalities. Among them, magnetic skyrmions, particle-like non-coplanar topological spin structures characterized by a non-zero integer topological charge called the skyrmion number (Nsk), have great potential for various spintronic applications, such as energy-saving, non-volatile memory and non-von Neumann devices4-7. Current pulses can initiate skyrmion creation in thin-film samples8-10 but require relatively large current densities, which probably causes Joule heating. Moreover, skyrmion creation is localized at a specific position in the film depending on the sample design. Here, we experimentally demonstrate an approach to skyrmion creation employing surface acoustic waves (SAWs); in asymmetric multilayers of Pt/Co/Ir, propagating SAWs induce skyrmions in a wide area of the magnetic film. Micromagnetic simulations reveal that inhomogeneous torque arising from both SAWs and thermal fluctuations creates magnetic textures, with pair structures consisting of a Néel skyrmion-like and an antiskyrmion-like structure. Subsequently, such pairs transform to a Néel skyrmion due to the instability of the antiskyrmion-like structure in a system with interfacial Dzyaloshinskii-Moriya interaction. Our findings provide a tool for efficient manipulation of topological spin objects without heat dissipation and over large areas, given that the propagation length of SAWs is of the order of millimetres.

Nonlocal accumulation, chemical potential, and Hall effect of skyrmions in Pt/Co/Ir heterostructure.

Magnetic skyrmion is a swirling topological spin texture behaving as an individual particle. It shows a gyro-motion similarly to that of a charged particle under a magnetic field, being led to the transverse shift to the electric current, i.e., skyrmion Hall effect. With the open boundaries of a sample, this results in an accumulation of skyrmions on one side and their depletion on the other side. Here we demonstrate experimentally that this effect propagates non-locally over tens of micrometers even where the electric current is absent, when the narrow wires bridge bar-shaped Pt/Co/Ir heterostructure thin film systems. This nonlocality can be understood in terms of the "chemical potential" gradient for the skyrmion bubble induced by the skyrmion Hall effect in the nonequilibrium steady state under the electric current. The present result shows that the skyrmion Hall effect acts as the skyrmion pump and the thermodynamic concepts can be applied to the aggregate of skyrmion bubbles.

Magnetic and magnetic inverse spin Hall effects in a non-collinear antiferromagnet.

The spin Hall effect (SHE)1-5 achieves coupling between charge currents and collective spin dynamics in magnetically ordered systems and is a key element of modern spintronics6-9. However, previous research has focused mainly on non-magnetic materials, so the magnetic contribution to the SHE is not well understood. Here we show that antiferromagnets have richer spin Hall properties than do non-magnetic materials. We find that in the non-collinear antiferromagnet10 Mn3Sn, the SHE has an anomalous sign change when its triangularly ordered moments switch orientation. We observe contributions to the SHE (which we call the magnetic SHE) and the inverse SHE (the magnetic inverse SHE) that are absent in non-magnetic materials and that can be dominant in some magnetic materials, including antiferromagnets. We attribute the dominance of this magnetic mechanism in Mn3Sn to the momentum-dependent spin splitting that is produced by non-collinear magnetic order. This discovery expands the horizons of antiferromagnet spintronics and spin-charge coupling mechanisms.

Publisher Correction: Magnetic and magnetic inverse spin Hall effects in a non-collinear antiferromagnet.

In this Letter, the formatting of some of the crystallographic axes was incorrect. This has been corrected online.

Synthetic ferrimagnet nanowires with very low critical current density for coupled domain wall motion.

Domain walls in ferromagnetic nanowires are potential building-blocks of future technologies such as racetrack memories, in which data encoded in the domain walls are transported using spin-polarised currents. However, the development of energy-efficient devices has been hampered by the high current densities needed to initiate domain wall motion. We show here that a remarkable reduction in the critical current density can be achieved for in-plane magnetised coupled domain walls in CoFe/Ru/CoFe synthetic ferrimagnet tracks. The antiferromagnetic exchange coupling between the layers leads to simple Néel wall structures, imaged using photoemission electron and Lorentz transmission electron microscopy, with a width of only ~100 nm. The measured critical current density to set these walls in motion, detected using magnetotransport measurements, is 1.0 × 1011 Am-2, almost an order of magnitude lower than in a ferromagnetically coupled control sample. Theoretical modelling indicates that this is due to nonadiabatic driving of anisotropically coupled walls, a mechanism that can be used to design efficient domain-wall devices.

Relationship of white matter lesions and severity of pushing behavior after stroke.

[Purpose] The relationship between white matter lesions (WMLs) and pushing behavior (PB) is still poorly understood. The purpose of this study was to investigate whether damage from WMLs affects the functional outcome of PB after acute stroke. [Subjects and Methods] In total, 37 patients were included. PB was assessed using the standardized Scale for Contraversive Pushing (SCP). Stroke types were classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), or lacunar syndrome using the Bamford classification. WML severity was categorized into four groups using the Fazekas visual scale. Thereafter, patients were divided into 4 groups according to the stroke type and/or presence of WMLs. The SCP, Trunk Control Test (TCT), Stroke Impairment Assessment Set (SIAS), and Barthel Index were the outcome measures. [Results] The SCP and TCT in patients with PACI without WMLs were better than those in patients with TACI with or without WMLs. Regarding SCP, TCT, and SIAS, patients with TACI had poorer values compared with PACI, regardless of WML severity. Barthel Index efficiency was not significantly different between the groups. [Conclusion] Our results suggest that moderate to severe WMLs and PACI had a relationship with PB severity and truncal balance.