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1.
Nat Commun ; 13(1): 6310, 2022 Oct 23.
Article in English | MEDLINE | ID: mdl-36274086

ABSTRACT

The observation of spinon excitations in the [Formula: see text] triangular antiferromagnet Ca3ReO5Cl2 reveals a quasi-one-dimensional (1D) nature of magnetic correlations, in spite of the nominally 2D magnetic structure. This phenomenon is known as frustration-induced dimensional reduction. Here, we present high-field electron spin resonance spectroscopy and magnetization studies of Ca3ReO5Cl2, allowing us not only to refine spin-Hamiltonian parameters, but also to investigate peculiarities of its low-energy spin dynamics. We argue that the presence of the uniform Dzyaloshinskii-Moriya interaction (DMI) shifts the spinon continuum in momentum space and, as a result, opens a zero-field gap at the Γ point. We observed this gap directly. The shift is found to be consistent with the structural modulation in the ordered state, suggesting this material as a perfect model triangular-lattice system, where a pure DMI-spiral ground state can be realized.

2.
Int J Oral Maxillofac Surg ; 50(8): 1113-1119, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33579625

ABSTRACT

A cross-sectional, nationwide survey was conducted in Japan to examine the relationship between tobacco smoking and oral diseases including implant failure. A questionnaire survey was sent to designated facilities by post, and 158 answered questions regarding implant loss. Smoking status, number of implant failures, and other related variables were collected from the participating dentists as secondary data. A total of 1966 patients who were treated with dental implants by participating dentists during the survey period were analysed. Among the total sample, 90 (5%) had early implant loss (≤12 months) and 153 (8%) had late implant loss (>12 months and ≤120 months). The number of pack-years was significantly higher in the total (early and late) implant loss group (31.2±15.9) than in the group with no implant loss (26.1±18.1) (P=0.026). In the multivariate analysis, the number of implants installed, smoking, and pack-years were significant factors for total implant loss. The adjusted odds ratio for implant failure for current smokers compared with never smokers was 2.07 (95% CI 1.19-3.62) for early implant loss and 1.48 (95% CI 0.92-2.37) for late implant loss. This study reaffirms that current smoking is associated with an increased risk of early implant loss, irrespective of the duration of smoking exposure.


Subject(s)
Dental Implants , Smokers , Cross-Sectional Studies , Dental Restoration Failure , Humans , Japan/epidemiology , Prevalence , Retrospective Studies , Surveys and Questionnaires
3.
J Phys Condens Matter ; 33(20)2021 Apr 28.
Article in English | MEDLINE | ID: mdl-33567414

ABSTRACT

TheH-Tphase diagram of Ni3V2O8is very rich and remains puzzling in a high magnetic field range. Through the state-of-the-art specific heat measurement in pulsed high field to 35 T and magnetocaloric effect measurement up to 45 T, we successfully construct the high-field phase diagram of Ni3V2O8for fields applied along thebaxis. The phase boundaries are corrected for previous results by magnetization and magneto-optical measurements. The resulting phase diagram shows that the high temperature incommensurate (HTI) phase develops well to high fields and low temperatures. In addition to the early reported C', C, low temperature incommensurate (LTI) and HTI phases, we explore a new magnetic ordered phase called HF1 in fields of 10-30 T. A multicritical point is also observed at 6 K and 8 T. Furthermore, the specific heat data reveal enhancements of the anomalies at ∼4 K, probably associated with a strong spin-lattice coupling in this frustrated multiferroic material.

4.
Phys Rev Lett ; 125(26): 267207, 2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33449724

ABSTRACT

The entire magnetization process of TlCuCl_{3} has been experimentally investigated up to 100 T employing the single-turn technique. The upper critical field H_{c2} is observed to be 86.1 T at 2 K. A convex slope of the M-H curve between the lower and upper critical fields (H_{c1} and H_{c2}) is clearly observed, which indicates that a particle-hole symmetry is broken in TlCuCl_{3}. By quantum Monte Carlo simulation and the bond-operator theory method, we find that the particle-hole symmetry breaking results from strong interdimer interactions.

5.
Nat Commun ; 10(1): 1059, 2019 03 05.
Article in English | MEDLINE | ID: mdl-30837479

ABSTRACT

Manipulating topological spin textures is a key for exploring unprecedented emergent electromagnetic phenomena. Whereas switching control of magnetic skyrmions, e.g., the transitions between a skyrmion-lattice phase and conventional magnetic orders, is intensively studied towards development of future memory device concepts, transitions among spin textures with different topological orders remain largely unexplored. Here we develop a series of chiral magnets MnSi1-xGex, serving as a platform for transitions among skyrmion- and hedgehog-lattice states. By neutron scattering, Lorentz transmission electron microscopy and high-field transport measurements, we observe three different topological spin textures with variation of the lattice constant controlled by Si/Ge substitution: two-dimensional skyrmion lattice in x = 0-0.25 and two distinct three-dimensional hedgehog lattices in x = 0.3-0.6 and x = 0.7-1. The emergence of various topological spin states in the chemical-pressure-controlled materials suggests a new route for direct manipulation of the spin-texture topology by facile mechanical methods.

6.
Nat Commun ; 10(1): 1229, 2019 03 15.
Article in English | MEDLINE | ID: mdl-30874548

ABSTRACT

Geometrical frustration and a high magnetic field are two key factors for realizing unconventional quantum states in magnetic materials. Specifically, conventional magnetic order can potentially be destroyed by competing interactions and may be replaced by an exotic state that is characterized in terms of quasiparticles called magnons, the density and chemical potential of which are controlled by the magnetic field. Here we show that a synthetic copper mineral, Cd-kapellasite, which comprises a kagomé lattice consisting of corner-sharing triangles of spin-1/2 Cu2+ ions, exhibits an unprecedented series of fractional magnetization plateaus in ultrahigh magnetic fields of up to 160 T. We propose that these quantum states can be interpreted as crystallizations of emergent magnons localized on the hexagon of the kagomé lattice.

8.
Phys Rev Lett ; 120(7): 077201, 2018 Feb 16.
Article in English | MEDLINE | ID: mdl-29542973

ABSTRACT

Fedotovite K_{2}Cu_{3}O(SO_{4})_{3} is a candidate of new quantum spin systems, in which the edge-shared tetrahedral (EST) spin clusters consisting of Cu^{2+} are connected by weak intercluster couplings forming a one-dimensional array. Comprehensive experimental studies by magnetic susceptibility, magnetization, heat capacity, and inelastic neutron scattering measurements reveal the presence of an effective S=1 Haldane state below T≅4 K. Rigorous theoretical studies provide an insight into the magnetic state of K_{2}Cu_{3}O(SO_{4})_{3}: an EST cluster makes a triplet in the ground state and a one-dimensional chain of the EST induces a cluster-based Haldane state. We predict that the cluster-based Haldane state emerges whenever the number of tetrahedra in the EST is even.

9.
Phys Rev Lett ; 118(7): 071803, 2017 Feb 17.
Article in English | MEDLINE | ID: mdl-28256869

ABSTRACT

We report on new results of a search for a two-photon interaction with axionlike particles (ALPs). The experiment is carried out at a synchrotron radiation facility using a "light shining through a wall (LSW)" technique. For this purpose, we develop a novel pulsed-magnet system, composed of multiple racetrack magnets and a transportable power supply. It produces fields of about 10 T over 0.8 m with a high repetition rate of 0.2 Hz and yields a new method of probing a vacuum with high intensity fields. The data obtained with a total of 27 676 pulses provide a limit on the ALP-two-photon coupling constant that is more stringent by a factor of 5.2 compared to a previous x-ray LSW limit for the ALP mass ≲0.1 eV.

11.
Sci Rep ; 7: 40585, 2017 01 12.
Article in English | MEDLINE | ID: mdl-28079159

ABSTRACT

Silencing of SOCS1 protein with shRNAi lentivirus (shR-SOCS1) led to partial reversion of the tumorigenic phenotype of B16F10-Nex2 melanoma cells. SOCS1 silencing inhibited cell migration and invasion as well as in vitro growth by cell cycle arrest at S phase with increased cell size and nuclei. Down-regulation of SOCS1 decreased the expression of epidermal growth factor receptor, Ins-Rα, and fibroblast growth factor receptors. The present work aimed at analyzing the SOCS1 cell signaling and expression of proteins relevant to tumor development. An RNA microarray analysis of B16F10-Nex2 melanoma cells with SOCS1 silenced by shRNAi-SOCS1 was undertaken in comparison with cells transduced with the empty vector. Among 609 differentially expressed genes, c-Kit, Met and EphA3 cytokine/tyrosine-kinase (TK) receptors were down regulated. A significant decrease in the expression of TK receptors, the phosphorylation of mediators of ERK1/2 and p38 pathways and STAT3 (S727) were observed. Subcutaneous immunization with shR-SOCS1-transduced viable tumor cells rendered protection against melanoma in a syngeneic model, with decreased expression of PD-L1 and of matrix metallo-proteinases (MMPs) and CD-10 in those cells. The present work shows the role of SOCS1 in murine melanoma development and the potential of SOCS1-silenced tumor cells in raising an effective anti-melanoma immune response.


Subject(s)
B7-H1 Antigen/metabolism , Disease Progression , Epithelial-Mesenchymal Transition , Immunity , Melanoma, Experimental/immunology , Melanoma, Experimental/pathology , Suppressor of Cytokine Signaling 1 Protein/metabolism , Animals , Bone Morphogenetic Protein Receptors, Type I/metabolism , Bone Morphogenetic Proteins/metabolism , CD8-Positive T-Lymphocytes/immunology , Cyclic AMP Response Element-Binding Protein/metabolism , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Neoplastic , Gene Silencing , Melanoma, Experimental/genetics , Melanoma-Specific Antigens/metabolism , Mice, Inbred C57BL , NF-kappa B/metabolism , Protective Agents/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Signal Transduction , Smad Proteins/metabolism , Transcription Factor AP-2/metabolism , Transcription, Genetic , Transforming Growth Factor beta/metabolism , Tumor Microenvironment , Up-Regulation/genetics
12.
Phys Rev Lett ; 112(24): 247201, 2014 Jun 20.
Article in English | MEDLINE | ID: mdl-24996104

ABSTRACT

Magnetization measurements and magnetotransmission spectroscopy of the solid oxygen α phase were performed in ultrahigh magnetic fields of up to 193 T. An abrupt increase in magnetization with large hysteresis was observed when pulsed magnetic fields greater than 120 T were applied. Moreover, the transmission of light significantly increased in the visible range. These experimental findings indicate that a first-order phase transition occurs in solid oxygen in ultrahigh magnetic fields, and that it is not just a magnetic transition. Considering the molecular rearrangement mechanism found in the O(2)-O(2) dimer system, we conclude that the observed field-induced transition is caused by the antiferromagnetic phase collapsing and a change in the crystal structure.

13.
Rev. andal. med. deporte ; 6(4): 139-145, dic. 2013. tab, ilus
Article in Spanish | IBECS | ID: ibc-118596

ABSTRACT

Objetivo. Analizar los efectos de un programa multidisciplinar de tratamiento de la obesidad (PMTO) sobre los factores de riesgo del Síndrome Metabólico (SM) en niños prepúberes, púberes y adolescentes de acuerdo con el género. Método. Participaron en el estudio 69 niños y adolescentes obesos entre 10 y 18 años de edad divididos en dos grupos: grupo de intervención (GI) (n = 37) y grupo control (GC) (n = 32). En el GI había 23 niñas, en el GC 14. El GI fue sometido a intervención multidisciplinar, con duración de 16 semanas. Se evaluaron parámetros antropométricos, aptitud cardiorrespiratoria y factores de riesgo para SM. Resultados. Se observó que el GI obtuvo reducción en la prevalencia de SM (- 35,8 % para género masculino y - 8,7 % para femenino), entre tanto se mantuvo el valor en las niñas del grupo GC y aumentó en los niños del GC (+ 11,1 %). En relación a dislipidemias, hubo una reducción en el GI para ambos géneros (- 7,2 % para el masculino; - 17,4 % para el femenino), y para el GC se observó aumento para el masculino (+ 22,2 %) y femenino (14,3 %). Las niñas del GI tuvieron mejoras significativas para las variables índice de masa corporal, circunferencia de cintura y cadera, y sensibilidad a la insulina, que no fueron observadas en el género masculino del GI, que presentaron aumento de masa magra. Conclusión. Los resultados del estudio muestran que 16 semanas de intervención multidisciplinar, basada en una terapia cognitivo-conductual, son suficientes para promover reducción de la prevalencia de SM y dislipidemias en niños y adolescentes obesos (AU)


Objetive. To analyze the effects of a multidisciplinary program of obesity treatment (PMTO) on risk factors for metabolic syndrome (MS) in children and adolescents at prepubertal, pubertal and adolescents stages according to gender. Method. he study included 69 obese children and adolescents aged 10 to 18 years. They were allocated to the intervention group (GI) (n = 37) and control group (GC) (n = 32). There were 23 girls in GI and 14 in GC. The GI was submitted to the multidisciplinary intervention, lasting 16 weeks. It was assessed anthropometric parameters, cardiorespiratory fitness and risk factor for MS. Results. We found that the GI achieved a reduction in the prevalence of MS (7.1 % for boys and 8.7 % for girls), and in GC a maintenance for girls and increasing for boys. For dyslipidemia, a reduction in GI for both genders (boys 78.6 % to 71.4 %; girls 82.6 % to 65.2 %), and increasing in GC for both genders. GI Girls had significant improvements for the variables, body mass index, waist circumference, hip circumference and insulin sensibility which was not observed in GI boys who increased lean body mass. Conclusion. The findings show that 16 weeks of multidisciplinary intervention based on cognitive behavioral therapy are sufficient to promote decreasing in the prevalence of MS and dyslipidemia in obese children and adolescents (AU)


Subject(s)
Humans , Male , Female , Child , Adolescent , Obesity/complications , Obesity/diagnosis , Obesity/therapy , Metabolic Syndrome/complications , Metabolic Syndrome/diagnosis , Gender and Health , Risk Factors , Behavior Therapy/methods , Cognitive Behavioral Therapy/methods , Obesity/diet therapy , Obesity/physiopathology , Sexual and Gender Disorders/complications , Sexual and Gender Disorders/diagnosis , Outcome and Process Assessment, Health Care , Evaluation of Results of Preventive Actions
14.
Rev Sci Instrum ; 81(4): 043701, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20441339

ABSTRACT

A high-speed polarizing microscope system combined with a 37 T pulse magnet has been developed. This system was applied to successfully visualize the field-induced collapse of charge-orbital ordering in a layered manganite La(1/2)Sr(3/2)MnO(4). Quantitative analyses of the obtained polarizing microscope images provided clear evidence of this transition in contrast to rather moderate changes in magnetization and magnetoresistance. The ability of this system to carry out quantitative analysis was further tested through the observation of Faraday rotation in a Tb(3)Ga(5)O(12) crystal. The Verdet constant determined from the polarizing images is in reasonable agreement with that in literature. Local intensity analyses of the images indicate that we can investigate magneto-optical signals within an accuracy of 0.85% in an area of 9.6 x 9.6 microm(2).

16.
Phys Rev Lett ; 102(21): 216402, 2009 May 29.
Article in English | MEDLINE | ID: mdl-19519118

ABSTRACT

We present a detailed quantum oscillation study of the Fermi surface of the recently discovered Yb-based heavy fermion superconductor beta-YbAlB4. We compare the data, obtained at fields from 10 to 45 T, to band structure calculations performed using the local density approximation. Analysis of the data suggests that f holes participate in the Fermi surface up to the highest magnetic fields studied. We comment on the significance of these findings for the unconventional superconducting properties of this material.

17.
Diabetes Res Clin Pract ; 83(3): 308-15, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19168253

ABSTRACT

The purpose of this study was to examine whether periodontal treatment incorporating topical antibiotic therapy affects on levels of glycohemoglobin (HbA1c) and serum high-sensitivity C-reactive protein (hs-CRP) in type 2 diabetic patients with periodontal disease, and to explore the relationship between CRP and glycemic control. The whole intervention group (n=32), which underwent anti-infectious periodontal treatment, showed only transient reduction in HbA1c levels without any change in hs-CRP, while the control group (n=17) did not show any changes in HbA1c or hs-CRP. Multiple regression analysis of all subjects revealed that BMI and change in hs-CRP correlated significantly with the reduction of HbA1c at 6 months after the periodontal treatment. Based on the results of multiple regression analysis, the intervention group was subdivided into two groups: those in which hs-CRP levels decreased (CRP-D group), and those in which hs-CRP levels unchanged or increased (CRP-N group) (n=16, respectively), and re-analysis was conducted based upon these subgroups. In the CRP-D subgroup, HbA1c was significantly reduced at the end of the study, but it did not decrease in the CRP-N subgroup. The decrease of HbA1c in the CRP-D subgroup following periodontal treatment was significantly greater than that in the CRP-N subgroup. BMI of each group remained unchanged in this study at the end of the study. Thus, the results suggested that periodontal treatment with topical antibiotics improves HbA1c through reduction of CRP, which may relate to amelioration of insulin resistance, in type 2 diabetic patients with periodontal disease.


Subject(s)
Anti-Infective Agents/therapeutic use , C-Reactive Protein/metabolism , Diabetes Mellitus, Type 2/complications , Glycated Hemoglobin/metabolism , Periodontal Diseases/blood , Periodontal Diseases/drug therapy , Adult , Aged , Dentition , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Female , Humans , Hypoglycemic Agents/therapeutic use , Male , Middle Aged , Treatment Outcome
18.
Braz. j. biol ; 67(4): 657-661, Nov. 2007. graf, tab
Article in English | LILACS | ID: lil-474189

ABSTRACT

Understanding the effects of metal contamination in the Amazon basin is important because of the potential impact on this region of high biodiversity. In addition, the significance of fish as the primary source of protein for the local human population (living either alongside the Amazon River or in the city of Manaus) highlights the need for information on the metal transfer through the food chain. Bioaccumulation of metals in fish can occur at significant rates through the dietary route, without necessarily resulting in death of the organism. The goal of this work was to expose an economic relevant species from the Amazon basin (tambaqui, Colossoma macropomum) to dietary cadmium (Cd) at concentrations of 0, 50, 100, 200, and 400 µg.g-1 dry food. Fish were sampled on days 15, 30, and 45 of the feeding trials. Tissues were collected for analysis of Cd concentration using graphite furnace atomic absorption spectrophotometry. Cd accumulation in the tissues occurred in the following order: kidney > liver > gills > muscle. Relative to other freshwater fish (e.g., rainbow trout, tilapia), tambaqui accumulated remarkably high levels of Cd in their tissues. Although Cd is known to affect Ca2+ homeostasis, no mortality or growth impairment occurred during feeding trials.


O entendimento dos efeitos da contaminação por metais na Bacia Amazônica é importante devido ao potencial impacto sobre esta região de elevada biodiversidade. Além disso, a relevância dos peixes como fonte primária de proteína para a população humana local (tanto nas comunidades ribeirinhas ao longo do rio Amazonas, quanto na cidade de Manaus), ressalta a necessidade de informação sobre a transferência de metais através da cadeia alimentar. Bioacumulação de metais em peixes pode ocorrer em taxas significativas através da dieta, sem necessariamente resultar na morte do indivíduo. O objetivo deste estudo foi expor cronicamente uma espécie de importância comercial nativa da Amazônia (tambaqui, Colossoma macropomum) a dietas enriquecidas com cádmio (Cd) em concentrações de 0, 50, 100, 200, and 400 µg.g-1 alimento seco. Os peixes foram amostrados nos dias 15, 30 e 45 do tratamento experimental. Os tecidos foram coletados para análise quanto a concentração de Cd por meio de espectrofotometria de absorção atômica acoplado a forno de grafite. O acúmulo de Cd nos tecidos ocorreu na seguinte ordem: rim > fígado > brânquias > músculo. Comparando-se com outras espécies de peixes de água doce (por exemplo, truta arco-íris, tilápia), o tambaqui acumulou níveis de Cd extremamente mais elevados em seus tecidos. Apesar do Cd ser conhecido por afetar a homeostase do Ca2+, não houve mortalidade ou retardo no crescimento durante os testes dietários.


Subject(s)
Animals , Humans , Cadmium/analysis , Diet , Fishes/metabolism , Water Pollutants, Chemical/analysis , Brazil , Cadmium/pharmacokinetics , Spectrophotometry, Atomic , Time Factors , Tissue Distribution , Water Pollutants, Chemical/pharmacokinetics
19.
Neuroscience ; 149(2): 256-62, 2007 Oct 26.
Article in English | MEDLINE | ID: mdl-17869007

ABSTRACT

We have recently found that a combination of ovariectomy (OVX) and chronic restraint stress causes cognitive dysfunction and reduces hippocampal CA3 neurons in female rats and that estrogen replacement suppresses the OVX/stress-induced behavioral and morphological changes. In this study, we examined the effect of Ginkgo biloba extract (EGb 761), a popular herbal supplement, on the cognitive dysfunction and neuromorphological change in OVX/stress-subjected rats. Female Fisher 344 rats were randomly divided into three groups: vehicle-treated OVX, EGb 761 (50 mg/kg) -treated OVX and vehicle-treated sham-operated control groups. Two months after ovariectomy, all animals received restraint stress for 21 days (6 h/day), and were then subjected to a novel object recognition test followed by morphological examination by Nissl staining. EGb 761 was orally administered once daily until the behavioral analysis was done. Treatment with EGb 761 improved memory impairment and neuronal loss of hippocampus in the OVX/stress-subjected group in the same ways as 17beta-estradiol. On the other hand, EGb 761 did not affect the loss of bone mineral density and increase in body weight after OVX, although 17beta-estradiol attenuated them. These results have important implications for neuroprotective and cognition enhancing effects of EGb 761 in postmenopausal women and suggest that the effects are mediated by a different mechanism from estrogen.


Subject(s)
Cognition Disorders/drug therapy , Ginkgo biloba/chemistry , Hippocampus/pathology , Neurons/pathology , Plant Extracts/pharmacology , Stress, Psychological/drug therapy , Animals , Bone Density/drug effects , Cell Count , Chronic Disease , Cognition Disorders/etiology , Cognition Disorders/psychology , Female , Organ Size/drug effects , Ovariectomy , Psychomotor Performance/drug effects , Psychomotor Performance/physiology , Rats , Rats, Inbred F344 , Recognition, Psychology/drug effects , Restraint, Physical , Stress, Psychological/pathology , Stress, Psychological/psychology , Uterus/drug effects , Weight Gain/drug effects
20.
Int Nurs Rev ; 54(2): 179-82, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17492992

ABSTRACT

AIM: To evaluate the clinical use of the Abilities Assessment Instrument (AAI) when used together with Mini Mental State Examination (MMSE) and Frontal Assessment Battery (FAB), thus examining the concurrent validity of the instrument. Also, to evaluate the effect of a learning program administered for elders with dementia. METHODS: Fourteen older people, who were afflicted with Alzheimer's disease or related dementias, were invited into a learning program. Measures were taken at baseline, at 3 months and 6 months to see the effects of the program. Instruments used in the study were the AAI, the MMSE and the FAB. FINDINGS: There were statistically significant differences measured by the Japanese version of the AAI in the subjects' abilities to perform the learning tasks between 3 and 6 months after intervention. No statistical significant differences were noted at any points in time measured by the MMSE or the FAB. CONCLUSION: The translated AAI promises to be a valid instrument for nurses' use in their day-to-day assessment of Japanese elders. The AAI appears also to be useful in learning programs with this population, and may have value as a screening tool.


Subject(s)
Dementia/diagnosis , Geriatric Assessment/methods , Nursing Assessment/methods , Activities of Daily Living , Aged , Aged, 80 and over , Dementia/rehabilitation , Disease Progression , Humans , Japan , Longitudinal Studies , Mass Screening/methods , Mass Screening/standards , Mental Status Schedule/standards , Nursing Assessment/standards , Nursing Evaluation Research , Patient Education as Topic/organization & administration , Psychometrics , Sensitivity and Specificity , Severity of Illness Index , Time Factors , Translating , Treatment Outcome
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