Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet.

Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn1.4Pt0.9Pd0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

Nonreciprocal Phonon Propagation in a Metallic Chiral Magnet.

The phonon magnetochiral effect (MChE) is the nonreciprocal acoustic and thermal transports of phonons caused by the simultaneous breaking of the mirror and time-reversal symmetries. So far, the phonon MChE has been observed only in a ferrimagnetic insulator Cu_{2}OSeO_{3}, where the nonreciprocal response disappears above the Curie temperature of 58 K. Here, we study the nonreciprocal acoustic properties of a room-temperature ferromagnet Co_{9}Zn_{9}Mn_{2} for unveiling the phonon MChE close to room temperature. Surprisingly, the nonreciprocity in this metallic compound is enhanced at higher temperatures and observed up to 250 K. This clear contrast between insulating Cu_{2}OSeO_{3} and metallic Co_{9}Zn_{9}Mn_{2} suggests that metallic magnets have a mechanism to enhance the nonreciprocity at higher temperatures. From the ultrasound and microwave-spectroscopy experiments, we conclude that the magnitude of the phonon MChE of Co_{9}Zn_{9}Mn_{2} mostly depends on the Gilbert damping, which increases at low temperatures and hinders the magnon-phonon hybridization. Our results suggest that the phonon nonreciprocity could be further enhanced by engineering the magnon band of materials.

Low-Field Bi-Skyrmion Formation in a Noncentrosymmetric Chimney Ladder Ferromagnet.

The real-space spin texture and the relevant magnetic parameters were investigated for an easy-axis noncentrosymmetric ferromagnet Cr_{11}Ge_{19} with Nowotny chimney ladder structure. Using Lorentz transmission electron microscopy, we report the formation of bi-Skyrmions, i.e., pairs of spin vortices with opposite magnetic helicities. The quantitative evaluation of the magnetocrystalline anisotropy and Dzyaloshinskii-Moriya interaction (DMI) proves that the magnetic dipolar interaction plays a more important role than the DMI on the observed bi-Skyrmion formation. Notably, the critical magnetic field value required for the formation of bi-Skyrmions turned out to be extremely small in this system, which is ascribed to strong easy-axis anisotropy associated with the characteristic helix crystal structure. The family of Nowotny chimney ladder compounds may offer a unique material platform where two distinctive Skyrmion formation mechanisms favoring different topological spin textures can become simultaneously active.

Electrochemical microdevices for rapid and on-site determination of the minimum inhibitory concentration of antibiotics.

A tool for rapid selection of appropriate antibiotics may be useful to maximize the benefits of their effectiveness against severe infectious diseases. In this study, we propose a microdevice that works with surface tension-driven sample introduction and impedance measurements for on-site, rapid estimation of suitable antibiotics.

Thermal Generation of Spin Current in an Antiferromagnet.

The longitudinal spin Seebeck effect has been investigated for a uniaxial antiferromagnetic insulator Cr(2)O(3), characterized by a spin-flop transition under magnetic field along the c axis. We have found that a temperature gradient applied normal to the Cr(2)O(3)/Pt interface induces inverse spin Hall voltage of spin-current origin in Pt, whose magnitude turns out to be always proportional to magnetization in Cr(2)O(3). The possible contribution of the anomalous Nernst effect is confirmed to be negligibly small. The above results establish that an antiferromagnetic spin wave can be an effective carrier of spin current.

Inflammatory histopathogenesis of nasopalatine duct cyst: a clinicopathological study of 41 cases.

OBJECTIVE: The aim of this study is to characterize immunohistochemical profiles of lining epithelia of nasopalatine duct cyst (NPC) as well as to correlate those findings with their clinicopathological features to understand the histopathogenesis of NPC. MATERIALS AND METHODS: Forty-one surgical specimens from NPC were examined for clinical profiles and expression of keratin-7, 13, MUC-1, and P63 by immunohistochemistry, compared to radicular cyst (RC) and maxillary sinusitis. RESULTS: Nasopalatine duct cyst was clinically characterized by male predominant occurrence: 44% of the cases involved tooth roots, and 70% with inflammatory backgrounds. Lining epithelia of NPCs without daughter cysts were immunohistochemically distinguished into three layers: a keratin 7-positive (+) ciliated cell layer in the surface, a keratin-13+ middle layer, and a MUC-1+/P63+ lower half, indicating that they were not respiratory epithelia, and the same layering pattern was observed in RC. However, those immunolocalization patterns of the main cyst lining with daughter cyst were exactly the same as those of daughter cyst linings as well as duct epithelia of mucous glands. CONCLUSIONS: Two possible histopathogenesis of NPC were clarified: one was inflammatory cyst like RC and the other was salivary duct cyst-like mucocele.

Particle-size dependent structural transformation of skyrmion lattice.

Magnetic skyrmion is a topologically protected particle-like object in magnetic materials, appearing as a nanometric swirling spin texture. The size and shape of skyrmion particles can be flexibly controlled by external stimuli, which suggests unique features of their crystallization and lattice transformation process. Here, we investigated the detailed mechanism of structural transition of skyrmion lattice (SkL) in a prototype chiral cubic magnet Cu2OSeO3, by combining resonant soft X-ray scattering (RSXS) experiment and micromagnetic simulation. This compound is found to undergo a triangular-to-square lattice transformation of metastable skyrmions by sweeping magnetic field (B). Our simulation suggests that the symmetry change of metastable SkL is mainly triggered by the B-induced modification of skyrmion core diameter and associated energy cost at the skyrmion-skyrmion interface region. Such internal deformation of skyrmion particle has further been confirmed by probing the higher harmonics in the RSXS pattern. These results demonstrate that the size/shape degree of freedom of skyrmion particle is an important factor to determine their stable lattice form, revealing the exotic manner of phase transition process for topological soliton ensembles in the non-equilibrium condition.

Propagation dynamics of spin excitations along skyrmion strings.

Magnetic skyrmions, topological solitons characterized by a two-dimensional swirling spin texture, have recently attracted attention as stable particle-like objects. In a three-dimensional system, a skyrmion can extend in the third dimension forming a robust and flexible string structure, whose unique topology and symmetry are anticipated to host nontrivial functional responses. Here we experimentally demonstrate the coherent propagation of spin excitations along skyrmion strings for the chiral-lattice magnet Cu2OSeO3. We find that this propagation is directionally non-reciprocal and the degree of non-reciprocity, as well as group velocity and decay length, are strongly dependent on the character of the excitation modes. These spin excitations can propagate over a distance exceeding 50 µm, demonstrating the excellent long-range ordered nature of the skyrmion-string structure. Our combined experimental and theoretical analyses offer a comprehensive account of the propagation dynamics of skyrmion-string excitations and suggest the possibility of unidirectional information transfer along such topologically protected strings.

Cementum-periodontal ligament complex regeneration using the cell sheet technique.

BACKGROUND AND OBJECTIVE: In the present study we evaluated if a multilayered human periodontal ligament cell sheet could reconstruct the physiological architecture of a periodontal ligament-cementum complex. MATERIAL AND METHODS: Human periodontal ligament cells were isolated and then cultured in dishes coated with a temperature-responsive polymer to allow cell detachment as a cell sheet. In the control group, human periodontal ligament cells were cultured in Dulbecco's modified Eagle's minimal essential medium containing 10% fetal bovine serum and 1% antibiotics. In the experimental group, human periodontal ligament cells were cultured in Dulbecco's modified Eagle's minimal essential medium and osteodifferentiation medium containing dexamethasone, ascorbic acid and beta-glycerophosphate. After 3 wk, scanning electron microscopy was carried out, in addition to staining for alkaline phosphatase activity and for calcium (using the Von Kossa stain). Then human periodontal ligament cell sheets were multilayered and placed onto dentin blocks. The constructs were transplanted subcutaneously into the back of immunodeficient rats. At 1 and 6 wk after transplantation, the animals were killed. Demineralized tissue sections were stained using hematoxylin and eosin, and Azan, and then analyzed. RESULTS: After 3 wk of culture in osteodifferentiation medium, human periodontal ligament cells produced mineral-like nodules and also showed positive staining for alkaline phosphatase, calcium (Von Kossa) and mRNA expression of type I collagen. By contrast, in the control group only weak alkaline phosphatase staining was observed, the Von Kossa stain was negative and there was no mRNA expression of type I collagen. Six weeks after transplantation with human periodontal ligament cells cultured in osteodifferentiation medium, most of the dentin surfaces showed a newly immature cementum-like tissue formation and periodontal ligament with perpendicular orientation inserted into the newly deposited cementum-like tissue. CONCLUSION: This study suggests that the multilayered temperature-responsive culture system can be used as a novel strategy for periodontal regeneration. The human periodontal ligament cell sheet technique may be applicable for regeneration of the clinical periodontal ligament-cementum complex.

Multiple-q noncollinear magnetism in an itinerant hexagonal magnet.

Multiple-q spin order, i.e., a spin texture characterized by a multiple number of coexisting magnetic modulation vectors q, has recently attracted attention as a source of nontrivial magnetic topology and associated emergent phenomena. One typical example is the triple-q skyrmion lattice state stabilized by Dzyaloshinskii-Moriya interactions in noncentrosymmetric magnets, while the emergence of various multiple-q states of different origins is expected according to the latest theories. Here, we investigated the magnetic structure of the itinerant polar hexagonal magnet Y3Co8Sn4, in which several distinctive mechanisms favoring multiple-q states are allowed to become active. Small-angle neutron-scattering experiments suggest the formation of incommensurate triple-q magnetic order with an in-plane vortex-like spin texture, which can be most consistently explained in terms of the novel four-spin interaction mechanism inherent to itinerant magnets. The present results suggest a new route to realizing exotic multiple-q orders and that itinerant hexagonal magnets, including the R 3 M 8Sn4 family with wide chemical tunability, can be a unique material platform to explore their rich phase diagrams.

Cephalometric evaluation after two-stage palatoplasty combined with a Hotz plate: a comparative study between the modified Furlow and Widmaier-Perko methods.

The effects on craniofacial growth of two different soft palate repair techniques in two-stage palatoplasty were investigated. This was a retrospective, cross-sectional cohort study of 68 children with non-syndromic, complete unilateral cleft lip and palate. Thirty-four patients were treated with the modified Furlow method (F-group) and the remaining 34 with the Widmaier-Perko method (P-group). Craniofacial growth was assessed by analyzing 12 angular and 12 linear measurements on lateral cephalograms. Composite facial diagrams from the two groups were compared with those of a control non-cleft group. Angular and linear measurements did not differ significantly between the two groups, implying that the craniofacial morphology was not affected by the difference in soft palate repair technique. However, small differences in anterior nasal spine and posterior nasal spine were found in cleft patients compared with controls. These findings suggest that the modified Furlow and Widmaier-Perko methods have a similar impact on craniofacial growth. Considering speech function, the modified Furlow method provides better craniofacial growth and speech function. However, the long-term effects of both methods on craniofacial growth after growth cessation remain to be determined.

Plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) and soluble TNF receptors in patients with anorexia nervosa.

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine with numerous immunological and metabolic activities. To study the role of TNF-alpha on the pathophysiology of anorexia nervosa and its complications, plasma concentrations of TNF-alpha, 2 soluble TNF receptors (sTNF-RI and sTNF-RII), and leptin were measured in 20 female patients with anorexia nervosa (AN) and 20 age-matched normal women (N). Plasma TNF-alpha concentrations in AN were significantly higher than those in N (4.1 +/- 0.6 pg/mL vs. 1.6 +/- 0.1 pg/mL; P < 0.01). Although no significant difference was observed in plasma sTNF-RI concentrations between the two groups, plasma sTNF-RII concentrations in AN were significantly higher than those in N (2094.0 +/- 138.5 pg/mL vs. 1569.5 +/- 84.0 pg/mL; P < 0.01). Plasma concentrations of TNF-alpha and sTNF-RII after treatment of 8 anorectic patients were not different from those before treatment, although body fat mass and plasma leptin concentrations significantly increased after treatment. Plasma TNF-alpha concentrations were not related to body fat mass in anorectic patients. These results suggest that the adipose tissue may not be the immediate source of TNF-alpha in anorectic patients and that TNF-alpha may contribute to the pathophysiology of immunological and metabolic abnormalities in anorexia nervosa.

Decrease in level of APG-2, a member of the heat shock protein 110 family, in murine brain following systemic administration of kainic acid.

APG-2 belongs to the heat shock protein 110 family. Although kainic acid (KA)-induced seizures are known to elicit expression of inducible heat shock protein 70 (HSP70) in the brain, no investigation has been carried out on the APG-2 level after excitatory amino acid-induced seizures. By means of an immunoblot assay, we determined the levels of HSP70 and APG-2 in discrete brain structures of mice after a single intraperitoneal injection of KA or N-methyl-D-aspartic acid (NMDA). APG-2 level was significantly decreased in frontal cortex, hippocampus, and striatum three days after the administration of KA, while HSP70 level was increased in these regions following the administration. In any of these regions, APG-2 levels were returned to the control levels 10 days after the administration. However, no significant changes were observed in levels of both HSP70 and APG-2 in hypothalamus, midbrain, medulla-pons, and cerebellum of the mice. By contrast, NMDA administration did not significantly affect both levels in any of the regions examined. These findings indicate that the transient decrease in APG-2 expression is one of the intracellular events elicited by signals peculiar to KA, but not by those peculiar to NMDA, in telencephalon of murine brain.

Phospholipid-deacylating enzymes of rat small intestinal mucosa.

1. Two phospholipase activities, provisionally designated as phospholipase activity I and phospholipase activity II, were found to be present in the mucosal homogenates of rat small intestine. These phospholipase activities were present in the membraneous particle fraction and were characterized in this study without further purification, using phosphatidylcholine as a substrate. Phospholipase activity I was assayed at pH 5.9 in the absence of deoxycholate, whereas phospholipase activity II was assayed at pH 9.4 in the presence of deoxycholate. Phospholipase activity I was more easily inactivated by heat treatment and trypsin digestion than phospholipase activity II. Both phospholipase activities were inhibited by diisopropyl-fluorophosphate but not by SH-binding reagents. 2. Phospholipase activity I had a pH optimum at 5.9. A sigmoid curve was obtained when the amount of the enzyme preparation was plotted against the phospholipase activity I. The unusually low activity found at low enzyme concentrations was enhanced by addition of the heat-inactivated enzyme preparation to a level where a linear relationship was found between the amount of enzyme and the activity. The effector present in the enzyme preparation was tentatively identified as fatty acid(s). The addition of oleic acid or linoleic acid to the incubation mixture enhanced the phospholipase activity I. At 1 mM levels of these fatty acids the highest activity was obtained when 1.5 mM phosphatidylcholine was used as a substrate. 3. The phospholipase activity II increased on addition of deoxycholate. In the presence of 5 mM deoxycholate, a pH optimum was found at 9.6. It was found that the maximal extent of hydrolysis of phosphatidylcholine in the incubation mixture was dependent on the concentration of deoxycholate. This indicates that deoxycholate facilitates the action of phospholipase activity II, presumably by forming deoxycholate-phosphatidylcholine mixed micelles. Phospholipase activity II was found to deacylate specifically the 2-acyl moiety of phospholipids.

Leptin in women with eating disorders.

The aim of the present study was to determine the factors controlling leptin secretion and to clarify the role of leptin in eating disorders. The subjects were 152 eating-disordered women with different fat mass, eating behavior, and endocrine abnormalities and 24 age-matched control subjects. The body fat mass, eating behavior score, and plasma leptin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), triiodothyronine (T3), free thyroxine (T4), insulin, and cortisol levels were evaluated for each subject. In patients with eating disorder, logarithmic values for leptin were significantly correlated with the body fat mass (r = .828, P < .001), eating behavior score (r = .777, P < .001), and LH (r = .465, P < .001), FSH (r = .440, P < .001), T3 (r = .572, P < .001), insulin (r = .410, P < .001), and cortisol (r = -.389, P < .001) levels. After adjusting for fat mass, the partial correlations of log leptin with LH, FSH, insulin, and cortisol were not statistically significant, but log leptin remained correlated with T3 (r = .390, P < .01). Stepwise regression analysis showed that the body fat mass and eating behavior score were significant determinants of leptin levels. These results suggest that eating behavior, as well as the body fat mass, is the control factor for leptin secretion in eating disorders.

Plasma estrogens in the assessment of fetoplacental function.

A retrospective study has been undertaken to assess the diagnostic value of plasma estriol (E3) determinations, as compared with determinations of other biochemical parameters, in predicting the outcome of pregnancy. The normal levels of plasma unconjugated and total E3 were determined on weekly samples obtained during the third trimester of 258 normal pregnancies. Weekly concurrent specimens of plasma and 24-hour urine collections were obtained from 17 high-risk pregnancies associated with hypertension, intrauterine growth retardation and diabetes. Determination of plasma unconjugated and total E3 were made along with human placental lactogen (HPL), urinary E3, and other biophysical parameters such as the oxytocin challenge test, non-stressed test, ultrasonography, etc. The results of plasma E3 were not reported nor used for the clinical management of the patient. The data suggests that weekly plasma determinations were of little value in the assessment of feto-placental status. Some observations on the extent of variability of plasma E3 are discussed.

Functional expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors precedes the development of cholinergic phenotype in embryonic rat septal cells in culture.

We examined the development of cholinergic neuronal functions and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) responses in cultured embryonic rat septal cells. Choline acetyltransferase activity was increased from 4 to 6 days in culture and reached a plateau at day 8. Acetylcholine release was increased from 6 to 8 days in culture. AMPA-induced increase in intracellular Ca(2+) level was observed at 3 days in culture and most of the AMPA-responsive cells coincided with high-K(+) responsive cells. These results suggest that cholinergic neurons develop their neuronal functions about 8 days under cultured conditions, and functional expression of AMPA receptors precedes the cholinergic functional development.

Cold pain prolongs gastric emptying of liquid but not solid meal: an electrical impedance tomography (EIT) study.

Stressful stimuli are reported to affect gastric emptying. However, methods for measuring gastric emptying are, in themselves, stressful. Electrical impedance tomography (EIT) is a method for measuring gastric emptying noninvasively. We used EIT to measure gastric emptying of liquid and solid meals to determine the effect of cold pain stress on gastric emptying. EIT (DAS-01P APT system; University of Sheffield, UK) was carried out in six healthy women (age, 21.6 +/- 0.4 [mean +/- SD] years) who had ingested a liquid (potage, 263 g; 139 kcal) or solid (beef patty, 205 g; 435 kcal) test meal. Cold pain stimuli consisted of repeated immersions of the subject's non-dominant hand into ice water (4 degrees C) for 1 min, with a 15-s recovery period between immersions, for a total of 20 min. For the control stimulus, water at 37 degrees C was used. The cold pain stimulus was applied immediately after the ingestion of a test meal. All studies were carried out randomly in each subject at intervals of more than 1 week. With cold pain, the half emptying time of the liquid meal was significantly greater than that with the control stimulus (47.6 +/- 26.1 min vs 28.1 +/- 10.8 min, P < 0.05). For the solid meal, the half emptying time did not differ between stimuli (101.9 +/- 44.8 min with cold pain vs 92.6 +/- 30.5 min with control stimulus). There were no significant differences in lag time between the liquid and solid meals. Cold pain stress delayed gastric emptying of liquid but not solid meals.

Three-dimensional computerized tomography angiography in patients with hyperacute intracerebral hemorrhage.

OBJECT: The authors confirm the usefulness of extravasation detected on three-dimensional computerized tomography (3D-CT) angiography in the diagnosis of continued hemorrhage and establishment of its cause in patients with acute intracerebral hemorrhage (ICH). METHODS: Thirty-one patients with acute ICH in whom noncontrast and 3D-CT angiography had been performed within 12 hours of the onset of hemorrhage and in whom conventional cerebral angiographic studies were obtained during the chronic stage were prospectively studied. Noncontrast CT scanning was repeated within 24 hours of the onset of ICH to evaluate hematoma enlargement. Findings indicating extravasation on 3D-CT angiography, including any abnormal area of high density on helical CT scanning, were observed in five patients; three of these demonstrated hematoma enlargement on follow-up CT studies. Thus, specificity was 60% (three correct predictions among five positives) and sensitivity was 100% (19 correct predictions among 19 negatives). Evidence of extravasation on 3D-CT angiography indicates that there is persistent hemorrhage and correlates with enlargement of the hematoma. Regarding the cause of hemorrhage, five cerebral aneurysms were visualized in four patients, and two diagnoses of moyamoya disease and one of unilateral moyamoya phenomenon were made with the aid of 3D-CT angiography. Emergency surgery was performed without conventional angiography in one patient who had an aneurysm, and it was clipped successfully. CONCLUSIONS: Overall, 3D-CT angiography was found to be valuable in the diagnosis of the cause of hemorrhage and in the detection of persistent hemorrhage in patients with acute ICH.

Reduction of hyponatremia in a schizophrenic with polydipsia-hyponatremia syndrome by surgical intervention.

In a chronic schizophrenic with polydipsia-hyponatremia syndrome, we observed physiological data consecutively before and after a successful LAPIDES vesicostomy for his bladder retention. Although his polydipsia was unchanged, frequency of hyponatremia was significantly reduced after the operation. We found that bladder retention might be one of the factors relevant to the prediction of hyponatremia from diurnal weight gain.