Band-driven switching of magnetism in a van der Waals magnetic semimetal.

Magnetic semimetals form an attractive class of materials because of the nontrivial contributions of itinerant electrons to magnetism. Because of their relatively low-carrier-density nature, a doping level of those materials could be largely tuned by a gating technique. Here, we demonstrate gate-tunable ferromagnetism in an emergent van der Waals magnetic semimetal Cr3Te4 based on an ion-gating technique. Upon doping electrons into the system, the Curie temperature (TC) sharply increases, approaching near to room temperature, and then decreases to some extent. This non-monotonous variation of TC accompanies the switching of the magnetic anisotropy, synchronously followed by the sign changes of the ordinary and anomalous Hall effects. Those results clearly elucidate that the magnetism in Cr3Te4 should be governed by its semimetallic band nature.

The Effect of Block Ratio and Structure on the Thermosensitivity of Double and Triple Betaine Block Copolymers.

AB-type and BAB-type betaine block copolymers composed of a carboxybetaine methacrylate and a sulfobetaine methacrylate, PGLBT-b-PSPE and PSPE-b-PGLBT-b-PSPE, respectively, were synthesized by one-pot RAFT polymerization. By optimizing the concentration of the monomer, initiator, and chain transfer agent, block extension with precise ratio control was enabled and a full conversion (~99%) of betaine monomers was achieved at each step. Two sets (total degree of polymerization: ~300 and ~600) of diblock copolymers having four different PGLBT:PSPE ratios were prepared to compare the influence of block ratio and molecular weight on the temperature-responsive behavior in aqueous solution. A turbidimetry and dynamic light scattering study revealed a shift to higher temperatures of the cloud point and micelle formation by increasing the ratio of PSPE, which exhibit upper critical solution temperature (UCST) behavior. PSPE-dominant diblocks created spherical micelles stabilized by PGLBT motifs, and the transition behavior diminished by decreasing the PSPE ratio. No particular change was found in the diblocks that had an identical AB ratio. This trend reappeared in the other set whose entire molecular weight approximately doubled, and each transition point was not recognizably impacted by the total molecular weight. For triblocks, the PSPE double ends provided a higher probability of interchain attractions and resulted in a more turbid solution at higher temperatures, compared to the diblocks which had similar block ratios and molecular weights. The intermediates assumed as network-like soft aggregates eventually rearranged to monodisperse flowerlike micelles. It is expected that the method for obtaining well-defined betaine block copolymers, as well as the relationship of the block ratio and the chain conformation to the temperature-responsive behavior, will be helpful for designing betaine-based polymeric applications.

Alternative Proximal Protection Method during Carotid Artery Stenting Using Combined Transbrachial and Transradial Artery Approaches.

Herein, we report a case of carotid artery stenting with proximal flow protection for severe stenosis of the left internal carotid artery using transbrachial and transradial artery approaches. Because an abdominal aortic aneurysm was present, we avoided the transfemoral approach. The procedure was successfully performed with a combination of an 8-Fr balloon guide catheter and microballoon catheter on separate axes. No complications such as pseudoaneurysm, thrombosis, or dissection were observed at the puncture site. The patient was discharged without complications and showed good outcomes at 3 months. This technique may offer a useful alternative for patients with severe stenosis who cannot be treated using a femoral artery approach.

Microbleed clustering in thalamus sign in CADASIL patients with NOTCH3 R75P mutation.

Background and objective: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebral microvascular disease characterized by the development of vascular dementia and lacunar infarctions. This study aimed to identify the genetic and clinical features of CADASIL in Japan. Methods: We conducted genetic analysis on a case series of patients clinically diagnosed with CADASIL. Clinical and imaging analyses were performed on 32 patients with pathogenic mutations in the NOTCH3 gene. To assess the presence of cerebral microbleeds (CMBs), we utilized several established rating scales including the Fazekas scale, Scheltens rating scale, and Microbleed Anatomical Rating Scale, based on brain MRI images. Results: Among the 32 CADASIL patients, 24 cases were found carrying the R75P mutation in NOTCH3, whereas the remaining eight cases had other NOTCH3 mutations (R75Q, R110C, C134F, C144F, R169C, and R607C). The haplotype analysis of the R75P mutation uncovered the presence of a founder effect. A brain MRI analysis revealed that cases with the R75P mutation had a significantly higher total number of CMBs, particularly in the thalamus when compared to patients with other NOTCH3 mutations. Among 15 out of 24 cases with the R75P mutation, we observed a notable clustering of CMBs in the thalamus, termed microbleed clustering in thalamus sign (MCT sign). Conclusion: We propose that the MCT sign observed in NOTCH3 R75P-related CADASIL patients may serve as a potentially characteristic imaging feature. This finding offers further insights into the interactions between genotypes and phenotypes between NOTCH3 and CADASIL.

Preparation of Water-Soluble Polyion Complex (PIC) Micelles with Random Copolymers Containing Pendant Quaternary Ammonium and Sulfonate Groups.

Cationic random copolymers (PCm) consisting of 2-(methacryloyloxy)ethyl phosphorylcholine (MPC; P) with methacroylcholine chloride (MCC; C) and anionic random copolymers (PSn) consisting of MPC and potassium 3-(methacryloyloxy)propanesulfonate (MPS; S) were prepared via a reversible addition-fragmentation chain transfer method. "m" and "n" represent the compositions (mol %) of the MCC and MPS units in the copolymers, respectively. The degrees of polymerization for the copolymers were 93-99. Water-soluble MPC unit contains a pendant zwitterionic phosphorylcholine group whose charges are neutralized in pendant groups. MCC and MPS units contain the cationic quaternary ammonium and anionic sulfonate groups, respectively. The stoichiometrically charge-neutralized mixture of a matched pair of PCm and PSn aqueous solutions resulted in the spontaneous formation of water-soluble PCm/PSn polyion complex (PIC) micelles. These PIC micelles have the MPC-rich surface and MCC/MPS core. These PIC micelles were characterized using 1H NMR, dynamic and static light scattering, and transmission electron microscopic measurements. The hydrodynamic radius of these PIC micelles depends on the mixing ratio of the oppositely charged random copolymers. The charge-neutralized mixture formed maximum-size PIC micelles.

Effect of Hydrophobicity and Salt on the Temperature Responsiveness of Polymeric Micelles Consisting of Hydrophobic and Sulfobetaine Chains.

The effect of the hydrophobicity of the core part and salt on the temperature responsiveness of polymeric micelles composed of sulfobetaine and hydrophobic blocks was investigated. Poly(sulfopropyl dimethylammonium propylacrylamide) (PSPP) was used as the sulfobetaine; poly(2-ethylhexyl acrylate) (PEHA), poly(n-butyl acrylate) (PnBA), poly(ethyl acrylate) (PEA), or poly(n-hexyl acrylate) (PnHA) was used as the hydrophobic polymer. Measurement of the transmittance revealed that the transition temperature of the sulfobetaine homopolymer could be controlled by adjusting the concentration, the degree of polymerization (DP), and the concentration of the added salt. The effect of the anionic species of the added salt due to the chemical structural properties of the sulfobetaine chain was consistent with the order of ionic species with strong structural destruction in the Hofmeister series. The temperature response and micelle formation behavior of the polymeric micelles according to the hydrophobicity of the core part and the preparation method were examined by static light scattering (SLS), fluorescence measurement with pyrene, dynamic light scattering (DLS), transmittance, and atomic force microscopy (AFM). Micelles that had EHA (solubility in water was 0.01 g/100 mL) as the core and did not show temperature responsiveness expressed temperature responsiveness at a lower hydrophobicity (solubility of nBA in water was 0.14 g/100 mL). nBA-b-SPP did not show temperature responsiveness due to the block ratio. However, when micelles were prepared by dialysis, smaller and more stable micelles could be formed in an equilibrium state, and temperature responsiveness was observed. Their transition temperature can be controlled by adjusting the ratio of the sulfobetaine blocks, the hydrophobicity of the core part, the concentration of the polymer aqueous solution, and the concentration of the added salt. Furthermore, like the sulfobetaine homopolymer, the effect depended on the anionic species of the added salt.

Enhancement of the Ivy Sign during an Ischemic Event in Moyamoya Disease.

We herein report a case of increased and expanded ipsilateral ivy sign paralleling the expansion of cerebral infarction in a patient with moyamoya disease. A 67-year-old woman visited our hospital with symptoms of left hemiplegia, left homonymous hemianopia, and left unilateral spatial neglect. Magnetic resonance imaging of the head showed cerebral infarction in the right parietal lobe. In addition, ivy signs were evident on fluid-attenuated inversion recovery imaging. These findings were enhanced by the expansion of cerebral infarction and disappeared once the ischemia resolved, implying hemodynamic changes. As a result of continuing medical treatment without antithrombotic therapy, the patient obtained a good outcome. Treatment for moyamoya disease in the acute phase is considered to require complex knowledge of multiple factors, such as the anatomical background of the individual patient and the progression grade of ischemia.

Layer-Number-Independent Two-Dimensional Ferromagnetism in Cr3Te4.

In a conventional magnetic material, a long-range magnetic order develops in three dimensions, and reducing a layer number weakens its magnetism. Here we demonstrate anomalous layer-number-independent ferromagnetism down to the two-dimensional (2D) limit in a metastable phase of Cr3Te4. We fabricated Cr3Te4 thin films by molecular-beam epitaxy and found that Cr3Te4 could host two distinct ferromagnetic phases characterized with different Curie temperatures (TC). One is the bulk-like "high-TC phase" showing room-temperature ferromagnetism, which is consistent with previous studies. The other is the metastable "low-TC phase" with TC ≈ 160 K, which exhibits a layer-number-independent TC down to the 2D limit in marked contrast with the conventional high-TC phase, demonstrating a purely 2D nature of its ferromagnetism. Such significant differences between two distinct phases could be attributed to a small variation in the doping level, making this material attractive for future ultracompact spintronics applications with potential gate-tunable room-temperature 2D ferromagnetism.

Spontaneous spin-valley polarization in NbSe2 at a van der Waals interface.

A proximity effect at a van der Waals (vdW) interface enables creation of an emergent quantum electronic ground state. Here we demonstrate that an originally superconducting two-dimensional (2D) NbSe2 forms a ferromagnetic ground state with spontaneous spin polarization at a vdW interface with a 2D ferromagnet V5Se8. We investigated the anomalous Hall effect (AHE) of the NbSe2/V5Se8 magnetic vdW heterostructures, and found that the sign of the AHE was reversed as the number of the V5Se8 layer was thinned down to the monolayer limit. Interestingly, the AHE signal of those samples was enhanced with the in-plane magnetic fields, suggesting an additional contribution to the AHE signal other than magnetization. This unusual behavior is well reproduced by band structure calculations, where the emergence of the Berry curvature along the spin-degenerate nodal lines in 2D NbSe2 by the in-plane magnetization plays a key role, unveiling a unique interplay between magnetism and Zeeman-type spin-orbit interaction in a non-centrosymmetric 2D quantum material.

COVID-19 with Rapid Progression to Hypoxemia Likely due to Imbalance between Ventilation and Blood Flow: A Case Report.

BACKGROUND: In COVID-19 pneumonia, cases of severe hypoxemia in the early stage and cases of sudden deterioration in respiratory status due to silent hypoxia leading to death, have been reported. CASE SUMMARY: A 70-year-old Japanese man with essential hypertension, dyslipidemia, chronic kidney disease and emphysema was hospitalized with the novel coronavirus disease. He had hypoxemia that was disproportionate to the severity of pneumonia indicated by computed tomography (CT), along with coagulation abnormalities. We speculated that there was a high possibility that he had developed ventilation and blood flow imbalance due to pulmonary intravascular coagulopathy (PIC) or hypoxic pulmonary vasoconstriction (HPV). In this case, early, short-term combination therapy with remdesivir, nafamostat mesylate and low-dose dexamethasone (Dex) was successful. CONCLUSION: In COVID-19 patients with multiple comorbidities who have hypoxemia and coagulation abnormalities that are disproportionate to the severity of pneumonia on CT, it is important to commence antiviral and anticoagulant therapy as soon as possible, followed by use of a low dose of Dex.

Plaque Protrusion in a Patient with Left Common Carotid Artery Stenting after Radiation Therapy: A Case Report.

Objective: We report a case of additional carotid artery stenting (CAS) for plaque protrusion occurring after initial CAS for radiation-induced common carotid artery (CCA) stenosis. Case Presentation: A 69-year-old man with a history of radiotherapy for laryngeal cancer presented to our hospital with sudden-onset right hemiparesis. Since vulnerable plaque of the left CCA was considered the embolic source for ischemic stroke, CAS was performed for left CCA stenosis. No perioperative complications were observed and the patient was discharged with a modified Rankin Scale score of 0. However, 1 month after CAS, cerebral embolism recurred. As protruding plaque was found on CTA, additional endovascular treatment was performed with intravascular ultrasonography. He was discharged without complications and showed a good outcome at 3 months. Conclusion: In CCA stenosis after radiotherapy, accelerated arteriosclerosis may cause drug-resistant cerebral embolism and plaque protrusion after CAS, making determination of the treatment strategy difficult. Appropriate treatment options need to be based on individual underlying diseases and plaque instability.

Complex Formation in the Sulfobetaine-Containing Entirely Ionic Block Copolymer/Ionic Homopolymer System and Their Temperature Responsivity.

The behavior of micelle formation in the sulfobetaine-containing entirely ionic block copolymer/ionic homopolymer system and its functional expression (temperature responsivity) were investigated. Poly(sulfopropyl dimethylammonium propylacrylamide) was used as the sulfobetaine, poly[3-(methacrylamido)propyl trimethylammonium chloride] was used as the cationic polymer, and poly(p-styrenesulfonic acid sodium salt) was used as the anionic polymer. The changes in transition temperature with the concentration and the behavior of micelle formation in the block-/cationic homopolymer and block-/anionic homopolymer system were compared and examined by transmittance, dynamic light scattering, atomic force microscopy, and 1H nuclear magnetic resonance. Only block-/cationic homopolymer systems with a core-shell (polyion complex-sulfobetaine) structure showed temperature responsivity of upper critical solution temperature type, and the responsiveness was dependent on the concentration. On the other hand, the block-/anionic homopolymer system had a core-shell structure at a concentration of 0.05 wt %, but temperature responsiveness was not observed at this concentration. At higher concentrations, electrostatic attraction caused the anionic homopolymer and block copolymer to interact as a whole, resulting in a loss of responsiveness. When the ionic homopolymer had a higher degree of polymerization than the sulfobetaine, it could not form a core-shell structure by interacting with the sulfobetaine and ionic polymer moieties of the block copolymer, thus resulting in the loss of responsiveness. The block-/ionic homopolymer system prepared by the reforming method through dialysis formed uniform and small micelles but lost responsiveness due to morphological stability and electrostatic interaction between the block copolymer and ionic homopolymer.

[A 74-year-old man who underwent carotid artery stenting with symptomatic right internal carotid artery stenosis with congenital agenesis of the left internal carotid artery].

A 74-year-old man visited our hospital with a 1-month history of awareness of wobbling while walking. Head MRI revealed fresh cerebral infarction in the territory of the right middle cerebral artery, and cervical carotid ultrasonography revealed severe stenosis at the origin of the right internal carotid artery. No left internal carotid artery could be confirmed, and no carotid canal was evident on CT of the head, suggesting congenital agenesis of the left internal carotid artery. Carotid artery stenting was performed for the stenosed right internal carotid artery that was refractory to medical treatment, obtaining a good outcome. Patients with congenital internal carotid artery agenesis show unique hemodynamics and anatomical features. Particularly in cases with cerebral infarction, an understanding of the etiology and complicated classification of disease types is needed, in addition to familiarity with comorbidities.

Microbleeds and clinical outcome in acute mild stroke patients treated with antiplatelet therapy: ADS post-hoc analysis.

BACKGROUND AND PURPOSE: In this post-hoc analysis using acute dual study dataset, the impacts of cerebral microbleeds (MBs) after mild stroke on clinical outcome were investigated. METHODS: The number of MBs on admission was categorized as 1) no MBs, 2) MBs 1-4, 3) MBs 5-9, and 4) MBs ≥ 10. The efficacy outcome was defined as neurological deterioration and stroke recurrence within 14 days. Safety outcomes included ICH and/or SAH as well as extracranial hemorrhages. RESULTS: Of the 1102 patients, 780 (71%) had no MBs on admission, while 230 (21%) had MBs 1-4, 48 (4%) had MBs 5-9, and 44 (4%) had MBs ≥ 10. The number of MBs was not associated with the neurological deterioration and/or stroke recurrence (p = 0.934), ICH and/or SAH (p = 0.743), and extracranial hemorrhage (p = 0.205). Favorable outcome was seem in 84% in the No MBs group, 83% in the MBs 1-4, 94% in the MBs 5-9, and 85% in the MBs ≥ 10 (p = 0.304). Combined cilostazol and aspirin therapy did not alter any rates of efficacy and safety outcomes among the no MBs, MBs 1-4, MBs 5-9, and MBs ≥ 10 groups compared to aspirin alone (all p > 0.05). By multivariate regression analysis, a history of ICH and diastolic blood pressure were the independent parameters to all of the MBs criteria (presence, MBs ≥ 5, and MBs ≥ 10). CONCLUSIONS: MBs did not alter the clinical outcome at 3 months of onset. Elevated diastolic blood pressure and a history of ICH were the essential parameters related to the MBs.

Spin-Orbit-Induced Ising Ferromagnetism at a van der Waals Interface.

Magnetocrystalline anisotropy, a key ingredient for establishing long-range order in a magnetic material down to the two-dimensional (2D) limit, is generally associated with spin-orbit interaction (SOI) involving a finite orbital angular momentum. Here we report strong out-of-plane magnetic anisotropy without orbital angular momentum, emerging at the interface between two different van der Waals (vdW) materials, an archetypal metallic vdW material NbSe2 possessing Zeeman-type SOI and an isotropic vdW ferromagnet V5Se8. We found that the Zeeman SOI in NbSe2 induces robust out-of-plane magnetic anisotropy in V5Se8 down to the 2D limit with a more than 2-fold enhancement of the transition temperature. We propose a simple model that takes into account the energy gain in NbSe2 in contact with a ferromagnet, which naturally explains our observations. Our results demonstrate a conceptually new magnetic proximity effect at the vdW interface, expanding the horizons of emergent phenomena achievable in vdW heterostructures.

Edinburgh Postnatal Depression Scale scores at 2-week post-partum may reflect those at 4-week post-partum: A single-center retrospective observational study.

AIM: Most Japanese institutions screen for post-partum depression (PPD) using the Edinburgh Postnatal Depression Scale (EPDS) at outpatient visits conducted at 2- and 4-week post-partum, but there are no published data on the usefulness of EPDS scores 2-week post-partum. In the present study, relationships between 2-week post-partum EPDS scores and 4-week post-partum EPDS scores were investigated to determine whether 2-week scores may facilitate early intervention in high-risk mothers. METHODS: A retrospective analysis of 451 deliveries from 2017 to 2019 was conducted at a single institution. EPDS scores were obtained using the Japanese EPDS 2- and 4-week post-partum, in conjunction with other perinatal data from medical records. RESULTS: In total, 334 of 451 mothers (74.1%) completed the EPDS at both 2- and 4-week post-partum and were included in the analysis. Of 48 who had higher scores 2-week post-partum, 21 (43.8%) continued to be at high risk of PPD. Of 284 who had lower scores 2-week post-partum, 9 (3.2%) transitioned to scores indicating high risk. Women considered high-risk 4-week post-partum tended to have exhibited higher scores 2-week post-partum. Women who had experienced more deliveries tended to exhibit lower scores, and psychiatric illness was strongly associated with higher EPDS scores (odds ratio 11.2, 95% confidence interval 3.7-33.8, P < 0.01). CONCLUSION: Two-week EPDS scores closely reflected 4-week scores, and may facilitate early intervention to prevent PPD. Primiparous mothers and those with a history of psychiatric illness should be followed-up closely.

Cilostazol Addition to Aspirin could not Reduce the Neurological Deterioration in TOAST Subtypes: ADS Post-Hoc Analysis.

BACKGROUND: Our previous trial acute dual study (ADS) reported that dual antiplatelet therapy (DAPT) using cilostazol and aspirin did not reduce the rate of short-term neurological worsening in non-cardioembolic stroke patients. Present post-hoc analysis investigated whether the impact of combined cilostazol and aspirin differed among stroke subtypes and factors associated with neurological deterioration and/or stroke recurrence. METHODS: Using the ADS registry, the rate of neurological deterioration, defined as clinical worsening and/or recurrent stroke, including transient ischemic attack was calculated. Stroke subtypes included large-artery atherosclerosis (LAA), small vessel occlusion (SVO), other determined etiology (Others), and undetermined etiology of stroke (Undetermined). RESULTS: Data of 1022 patients were analyzed. Deterioration was seen in 104 (10%) patients, and the rates were not markedly different between patients treated with DAPT vs. aspirin in any stroke subtypes: LAA, 19% vs. 11%, (p=0.192); SVO, 10% vs. 10% (p=1.000); Others, 6% vs. 6% (p=1.000); Undetermined, 11% vs. 8% (p=0.590). Diabetes mellitus was the independent factor associated with deterioration (odds ratio 4.360, 95% confidence interval 1.139-16.691, p=0.032) in the LAA group. Age (1.030 [1.004-1.057], p=0.026), systolic blood pressure (1.012 [1.003-1.022], p=0.010), and infarct size (2.550 [1.488-4.371], p=0.001) were associated with deterioration in SVO group, and intracranial stenosis/occlusion was associated with it in the Undetermined group (3.744 [1.138-12.318], p=0.030). CONCLUSIONS: Combined cilostazol and aspirin did not reduce the rate of short-term neurological deterioration in any clinical stroke subtype. The characteristics of patients whose condition deteriorates in the acute period may differ based on the stroke subtypes.

Collapse Behavior of Polyion Complex (PIC) Micelles upon Salt Addition and Reforming Behavior by Dialysis and Its Temperature Responsivity.

Temperature-responsive polyion complex (PIC) micelles were prepared by using two diblock copolymers composed of a sulfobetaine chain (poly(sulfopropyldimethylammonium propylacrylamide), PSPP) and ionic chains (poly(sodium styrenesulfonate), PSSNa, or poly(3-(methacrylamido)propyltrimethylammonium chloride), PMAPTAC). Because the core is PIC and the shell is sulfobetaine with UCST-type temperature response, the corona expands and contracts in response to temperature. To control the size and uniformity of the PIC micelles, the collapse of PIC micelles by salt addition and the reforming behavior by dialysis were investigated by transmittance, DLS, TEM, AFM, and 1H NMR measurements. Investigation of the ionic species dependence of the added salt in the collapse behavior of PIC micelles revealed that it was dependent on the anionic species, although no dependence on the cationic species was observed. Its effectiveness was in the order of I- > Br- > Cl- > F-, which is in agreement with the order of ionic species with strong structural destruction in the Hofmeister series. Heterogeneous and large PIC micelles were formed by the simple mixing method. They collapsed by salt addition and were reformed by the dialysis method to form uniform and smaller PIC micelles. This is considered to be because a uniform and smaller micelle is formed to reform in equilibrium state by dialysis. The temperature response of PIC micelles formed by the simple mixing method and PIC micelles reformed by dialysis showed nearly the same temperature-transmittance curves. These results indicate that the temperature response of PIC micelles is affected by the concentration rather than the hydrodynamic radius. Furthermore, the stability of PIC micelles was found to be affected by the concentration temperature (the temperature at the time of concentration).