Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.124
Filtrar
1.
Nature ; 563(7732): E29, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30237480

RESUMEN

Four incorrect figure citations in this Letter have been corrected online.

2.
Nature ; 560(7719): 466-470, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30135529

RESUMEN

The inversion of inhomogeneous physical states has great technological importance; for example, active noise reduction relies on the emission of an inverted sound wave that interferes destructively with the noise of the emitter1, and inverting the evolution of a spin system by using a magnetic-field pulse enables magnetic resonance tomography2. In contrast to these examples, inversion of a distribution of ferromagnetic or ferroelectric domains within a material is surprisingly difficult: field poling creates a single-domain state, and piece-by-piece inversion using a scanning tip is impractical. Here we report inversion of entire ferromagnetic and ferroelectric domain patterns in the magnetoelectric material Co3TeO6 and the multiferroic material Mn2GeO4, respectively. In these materials, an applied magnetic field reverses the magnetization or polarization, respectively, of each domain, but leaves the domain pattern intact. Landau theory indicates that this type of magnetoelectric inversion is universal across materials that exhibit complex ordering, with one order parameter holding the memory of the domain structure and another setting its overall sign. Domain-pattern inversion is only one example of a previously unnoticed effect in systems such as multiferroics, in which several order parameters are available for combination. Exploring these effects could therefore advance multiferroics towards new levels of functionality.

4.
Nano Lett ; 17(5): 2865-2870, 2017 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-28350468

RESUMEN

Constructing quantum devices comprises various challenging tasks, especially when concerning their nanoscale geometry. For quantum color centers, the traditional approach is to fabricate the device structure after the nondeterministic placement of the centers. Reversing this approach, we present the controlled generation of quantum centers in silicon carbide (SiC) by focused proton beam in a noncomplex manner without need for pre- or postirradiation treatment. The generation depth and resolution can be predicted by matching the proton energy to the material's stopping power, and the amount of quantum centers at one specific sample volume is tunable from ensembles of millions to discernible single photon emitters. We identify the generated centers as silicon vacancies through their characteristic magnetic resonance signatures and demonstrate that they possess a long spin-echo coherence time of 42 ± 20 µs at room temperature. Our approach hence enables the fabrication of quantum hybrid nanodevices based on SiC platform, where spin centers are integrated into p-i-n diodes, photonic cavities, and mechanical resonators.

5.
Br J Dermatol ; 177(1): 229-237, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28028810

RESUMEN

BACKGROUND: In extramammary Paget disease (EMPD), Paget cells are sometimes detected outside the clinical border (subclinical extension). However, the spreading pattern of Paget cells in subclinical extension remains unclear. In addition, the macroscopic appearances of lesions accompanied by subclinical extension are totally unknown. OBJECTIVES: To characterize the spreading pattern of Paget cells as well as the macroscopic appearance of lesions of EMPD with subclinical extension. METHODS: Nineteen patients with primary anogenital EMPD underwent mapping biopsies and excisional surgeries; biopsy samples were then taken at the periphery of well-demarcated lesions. Samples were transparentized and subjected to whole-mount immunostaining with anticytokeratin 7 antibody to label Paget cells. The histological border was evaluated in three dimensions by two-photon microscopy. The shape and location of the histological border were compared with those of the clinical border. RESULTS: In 21 samples taken at the lesion where subclinical extension was not shown by mapping biopsy, the shape and location of the histological border were almost identical to those of the clinical border. However, two samples exhibited small foci of Paget cells outside the clinical border, showing subclinically extended satellite lesions. In the two samples taken at the lesions where subclinical extension was shown by mapping biopsy, a continuous arrangement of Paget cells extending beyond the clinical border was identified. Subclinically extended Paget cells were detected solely outside hypopigmented patches with erythema. CONCLUSIONS: In EMPD, at least two patterns of subclinical extension exist: continuous and satellite lesions. Subclinical extension might exist preferentially outside hypopigmented patches with erythema.


Asunto(s)
Neoplasias del Ano/patología , Enfermedad de Paget Extramamaria/patología , Neoplasias Cutáneas/patología , Neoplasias Urogenitales/patología , Adulto , Anciano , Anciano de 80 o más Años , Dermoscopía/métodos , Femenino , Humanos , Hipopigmentación/patología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Enfermedad de Paget Extramamaria/cirugía , Fotones , Cuidados Preoperatorios , Neoplasias Cutáneas/cirugía
6.
Ultrasound Obstet Gynecol ; 50(6): 781-787, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27943496

RESUMEN

OBJECTIVES: Cervical pregnancy (CP) is a rare type of ectopic pregnancy. While methotrexate (MTX) is generally the first-line method of choice for clinically stable women, there is still no consensus on the most appropriate treatment for this abnormal pregnancy. The aim of this study was to investigate the efficacy of a single local MTX injection under transvaginal ultrasound guidance for the initial treatment of CP and to assess post-treatment fertility. METHODS: We reviewed retrospectively 15 patients with CP treated with local MTX injection under transvaginal ultrasound guidance. In all patients, the serum human chorionic gonadotropin (hCG) levels were monitored and the gestational sac was evaluated using ultrasonography after treatment. Magnetic resonance imaging (MRI) was performed as necessary. We evaluated the patients' clinical characteristics and clinical course after treatment, the efficacy of the treatment and the post-treatment fertility in patients desiring subsequent pregnancy. RESULTS: The median estimated gestational age at the time of MTX injection was 6 + 2 (range, 5 + 2 to 11 + 0) weeks. All 15 patients were treated successfully, without the need for blood transfusion or surgical procedures; however, three patients required an additional local MTX injection due to a poor decline in serum hCG level following the initial injection, while one patient required uterine artery embolization due to persistent vaginal bleeding and an enlarging gestational sac with blood vessels visible on contrast-enhanced MRI. The mean time following initial MTX injection for hCG normalization was 43.8 (95% CI, 33.3-54.3) days and for resumption of menses was 68.4 (95% CI, 51.9-84.9) days. Seven of the 10 women desiring subsequent pregnancy following treatment had uneventful pregnancy, one became pregnant but miscarried spontaneously at 8 weeks of gestation, one was treated by laparoscopic surgery after diagnosis of a tubal pregnancy and one did not conceive. CONCLUSIONS: A single, ultrasound-guided, local MTX injection is apparently effective for the treatment of CP without the need for concomitant procedures or surgical intervention. Furthermore, this conservative technique both preserves fertility and allows for the possibility of subsequent uneventful pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Abortivos no Esteroideos/administración & dosificación , Cuello del Útero/diagnóstico por imagen , Metotrexato/administración & dosificación , Embarazo Ectópico/diagnóstico por imagen , Embarazo Ectópico/tratamiento farmacológico , Ultrasonografía Intervencional , Adulto , Cuello del Útero/patología , Femenino , Fertilidad , Humanos , Embarazo , Embarazo Ectópico/patología , Estudios Retrospectivos , Resultado del Tratamiento
7.
J Periodontal Res ; 50(4): 500-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25223277

RESUMEN

BACKGROUND AND OBJECTIVE: Endoplasmic reticulum (ER) stress is the cell response that activates the unfolded protein response (UPR) pathway in a variety of conditions, such as inflammation and bone metabolism. The UPR may be associated with the pathogenesis of periodontal disease because the disease is inflammatory in nature, and alveolar bone resorption is a characteristic feature of the disease. However, the relationship between ER stress and alveolar bone resorption observed in periodontal disease remains elusive. MATERIAL AND METHODS: C57BL/6 mice were orally administered Porphyromonas gingivalis, a representative periodontopathic bacterium, in the presence or absence of a chemical chaperone, 4-phenylbutyrate (4-PBA). The gene expression of UPR-related molecules and cytokines in gingival tissues were analyzed using real-time polymerase chain reaction, and alveolar bone resorption and osteoclast numbers were evaluated histologically. The in vitro effect of 4-PBA on the differentiation of mouse bone marrow cells induced by receptor activator of nuclear factor-κB ligand in the presence of macrophage colony-stimulating factor was analyzed. RESULTS: The gene expression levels of UPR-related molecules and proinflammatory cytokines and alveolar bone resorption were significantly increased in P. gingivalis-administered mice. UPR-related gene expression and alveolar bone resorption were significantly suppressed by the administration of 4-PBA. However, no effect of 4-PBA was observed for proinflammatory cytokine expression in gingival tissues. Osteoclastic differentiation of bone marrow cells was also suppressed by 4-PBA with a concomitant reduction in the gene expression of cathepsin K and tartrate-resistant alkaline phosphatase genes. CONCLUSION: ER stress induced by oral administration of P. gingivalis is involved in alveolar bone resorption independent of inflammatory cytokines in mice.


Asunto(s)
Pérdida de Hueso Alveolar/microbiología , Estrés del Retículo Endoplásmico/fisiología , Periodontitis/microbiología , Pérdida de Hueso Alveolar/patología , Animales , Células de la Médula Ósea/efectos de los fármacos , Catepsina K/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/análisis , Modelos Animales de Enfermedad , Encía/química , Encía/efectos de los fármacos , Mediadores de Inflamación/análisis , Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Chaperonas Moleculares/farmacología , Osteoclastos/efectos de los fármacos , Osteoclastos/patología , Fenilbutiratos/farmacología , Porphyromonas gingivalis/fisiología , Ligando RANK/farmacología , Fosfatasa Ácida Tartratorresistente/efectos de los fármacos , Respuesta de Proteína Desplegada/fisiología
10.
Br J Dermatol ; 170(5): 1048-55, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24372073

RESUMEN

BACKGROUND: There have been extensive studies regarding which types of T lymphocytes are involved in psoriasis vulgaris (PV). However, it has remained unclear which types of T lymphocytes might directly contribute to psoriasiform epidermal and vascular hyperplasia. OBJECTIVES: To understand the role of T-cell receptor (TCR)Vα24+ invariant natural killer (iNK)T cells in the development of PV. METHODS: Seventeen patients were enrolled in this study. Using biopsy samples of PV plaques, TCRVα24(+) iNKT cells were investigated regarding their cytokine production to understand their roles in development of disease. RESULTS: The number of interferon (IFN)-γ+ iNKT cells correlated with the length of the psoriasiform hyperplasia rete ridge and the Psoriasis Area and Severity Index. IFN-γ+ iNKT cells in psoriatic skin exhibited higher C-C chemokine receptor (CCR)5 expression, and the amount of C-C chemokine ligand (CCL)5, a ligand for CCR5, was increased in capillary veins of psoriasis plaques. CCR5+ iNKT-cell numbers significantly correlated with the number of capillary vein endothelial cells expressing CCL5 in PV. Furthermore, the number of CCL5+ capillary veins correlated with the maximum rete ridge length. CONCLUSIONS: IFN-γ/CCR5 expression in iNKT cells and CCL5 expression in vessels of dermal papillae correlate with the development of psoriasiform hyperplasia and microabscess. We propose that these iNKT cells may become useful targets for development of novel therapeutic approaches to PV.


Asunto(s)
Quimiocina CCL5/metabolismo , Interferón gamma/inmunología , Células T Asesinas Naturales/inmunología , Psoriasis/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Adulto , Anciano , Capilares/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Pharmacogenomics J ; 13(1): 52-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21987091

RESUMEN

Functional single-nucleotide polymorphisms (SNPs) in inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) (rs28493229) and caspase-3 (CASP3) (rs113420705; formerly rs72689236) are associated with susceptibility to Kawasaki's disease (KD). To evaluate the involvement of these 2 SNPs in the risk for intravenous immunoglobulin (IVIG) unresponsiveness, we investigated 204 Japanese KD patients who received a single IVIG dose of 2 g kg(-1) (n=70) or 1 g kg(-1) daily for 2 days (n=134). The susceptibility allele of both SNPs showed a trend of overrepresentation in IVIG non-responders and, in combined analysis of these SNPs, patients with at least 1 susceptible allele at both loci had a higher risk for IVIG unresponsiveness (P=0.0014). In 335 prospectively collected KD patients who were treated with IVIG (2 g kg(-1)), this 2-locus model showed a more significant association with resistance to initial and additional IVIG (P=0.011) compared with individual SNPs. We observed a significant association when all KD patients with coronary artery lesions were analyzed with the 2-locus model (P=0.0031). Our findings strongly suggest the existence of genetic factors affecting patients' responses to treatment and the risk for cardiac complications, and provide clues toward understanding the pathophysiology of KD inflammation.


Asunto(s)
Caspasa 3/genética , Vasos Coronarios/patología , Inmunoglobulinas Intravenosas/administración & dosificación , Síndrome Mucocutáneo Linfonodular/genética , Síndrome Mucocutáneo Linfonodular/patología , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Alelos , Pueblo Asiatico/genética , Niño , Vasos Coronarios/enzimología , Resistencia a Medicamentos , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Síndrome Mucocutáneo Linfonodular/enzimología , Polimorfismo de Nucleótido Simple , Estudios Prospectivos
14.
Clin Radiol ; 68(1): e21-6, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23146553

RESUMEN

AIM: To analyse the correlation between computed tomography (CT) findings of small lung adenocarcinomas and the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society Classification of Lung Adenocarcinoma. MATERIALS AND METHODS: A retrospective review of 300 lung adenocarcinoma lesions (size ≤20 mm) after surgical resection in 295 consecutive patients was performed. Tumours were defined as air-containing type if the ratio of the maximum dimension of the tumour on mediastinal windows to the maximum dimension of the tumour on lung windows was ≤50%, and as solid-density type if the ratio was >50%. The incidence between CT findings (air bronchogram, vascular involvement, pleural tags, notches, and spiculation) and pathological findings were investigated. RESULTS: Of the 142 air-containing lesions, 114 were adenocarcinoma in situ (AIS), 28 were minimally invasive adenocarcinoma (MIA), and none of the lesions were invasive adenocarcinoma. Of the 158 solid-density lesions, 30 were AIS, 24 were MIA, and 104 were invasive adenocarcinoma. Notches and pleural tags were commonly observed in cases of invasive adenocarcinoma (p < 0.05). CONCLUSIONS: In the air-containing type of small lung adenocarcinomas, AIS and MIA were observed but no cases of invasive adenocarcinoma were found. The presence of notches and pleural tags were a significant factor in invasive adenocarcinoma.


Asunto(s)
Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/patología , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Adenocarcinoma/clasificación , Adenocarcinoma del Pulmón , Adulto , Anciano , Anciano de 80 o más Años , Aire , Broncografía , Femenino , Humanos , Neoplasias Pulmonares/clasificación , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Carga Tumoral
15.
J Chem Phys ; 138(7): 074904, 2013 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-23445032

RESUMEN

Phase transition from body-centered-cubic spheres to cylinders in a diblock copolymer melt under an external electric field is investigated by means of real-space dynamical self-consistent field theory. Different phase transition kinetic pathways and different cylindrical domains arrangements of the final phase are observed depending on the strength and direction of the applied electric field. Various transient states have been identified depending on the electric field being applied along [111], [100], and [110] directions. The electric field should be above a certain threshold value in order the transition to occur. A "dynamic critical exponent" of the transition is found to be about 3/2, consistent with other order-order transitions in diblock copolymers under electric field.

18.
Artículo en Inglés | MEDLINE | ID: mdl-24050076

RESUMEN

Vibrio cholerae O139 is an etiology of cholera in Thailand. We determined to prepare a rapid test to detect V cholerae O139 using an immunochromatographic method to be used for surveillance and use in community laboratories. We conjugated murine monoclonal antibodies specific to the lipopolysaccharide of V. cholerae O139 with colloidal gold particles. The sensitivity of the test was determined using 10-fold dilutions of V. cholerae O139. The lowest number of bacterial cells detected by the test was 10(6) cfu/ml. The specificity was determined using 51 isolates of pure cultures, including V. cholerae serogroups O1, O139, and non-O1/non-O139 and other enteric bacteria; 27 rectal swab specimens and 100 specimens of enriched alkaline peptone water, 50 of which contained V. cholerae O1 and the other did not contain V. cholerae O1. The rapid test showed specificity to V cholerae O139 and no cross reaction with V cholerae O1, V. cholerae non-O1/ non-O139, and other enteric bacteria. The test is rapid, simple and easy to use.


Asunto(s)
Heces/microbiología , Vibriosis/diagnóstico , Vibrio cholerae O139/inmunología , Cromatografía de Afinidad , ADN Bacteriano/análisis , Sensibilidad y Especificidad , Serotipificación , Tailandia , Factores de Tiempo , Vibriosis/inmunología
19.
Front Oncol ; 13: 1214977, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37483497

RESUMEN

Objectives: To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC). Methods: In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC. Results: Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types. Conclusions: A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

20.
Phys Rev Lett ; 108(7): 077204, 2012 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-22401248

RESUMEN

The olivine compound Mn(2)GeO(4) is shown to feature both a ferroelectric polarization and a ferromagnetic magnetization that are directly coupled and point along the same direction. We show that a spin spiral generates ferroelectricity, and a canted commensurate order leads to weak ferromagnetism. Symmetry suggests that the direct coupling between the ferromagnetism and ferroelectricity is mediated by Dzyaloshinskii-Moriya interactions that exist only in the ferroelectric phase, controlling both the sense of the spiral rotation and the canting of the commensurate structure. Our study demonstrates how multicomponent magnetic structures found in magnetically frustrated materials like Mn(2)GeO(4) provide a new route towards functional materials that exhibit coupled ferromagnetism and ferroelectricity.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA