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1.
Nat Commun ; 9(1): 4414, 2018 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-30356051

RESUMEN

Plastic deformation of metallic glasses (MGs) has long been considered to be confined to nanoscale shear bands, but recently an affected zone around the shear band was found. Yet, due to technical limitations, the shear-band affected zone (SBAZ), which is critical for understanding shear banding and design of ductile MGs, has yet to be precisely identified. Here, by using magnetic domains as a probe with sufficiently high sensitivity and spatial resolution, we unveil the structure of SBAZs in detail. We demonstrate that shear banding is accompanied by a micrometer-scale SBAZ with a gradient in the strain field, and multiple shear bands interact through the superimposition of SBAZs. There also exists an ultra-long-range gradual elastic stress field extending hundreds of micrometers away from the shear band. Our findings provide a comprehensive picture on shear banding and are important for elucidating the micro-mechanisms of plastic deformation in glasses.

2.
Eye (Lond) ; 31(5): 698-707, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28085140

RESUMEN

PurposeThe purpose of the study was to investigate nailfold microvascular morphology in exfoliation syndrome with or without glaucoma (XFS/XFG) compared with primary open-angle glaucoma (POAG) and control subjects using nailfold capillary videomicroscopy.Patients and methodsWe used a JH-1004 capillaroscope to perform nailfold capillary videomicroscopy on the fourth and fifth digit of the non-dominant hand. We enrolled 56 XFS/XFG patients, 87 POAG patients, and 75 control subjects. Masked observers graded the videos for hemorrhages, avascular zones ≥200 microns (µm), and degree of microvascular tortuosity on a four-point subjective scale. Multivariable odds ratios, 95% confidence intervals and P-for trends for assessing the relation between morphological changes and POAG or XFS/XFG were obtained from logistic regression analyses. We also assessed this relation with XFS/XFG compared with POAG in multivariable models.ResultsAfter adjusting for multiple covariates, nailfold hemorrhages, avascular zones ≥200 µm, and higher degree of vascular tortuosity were more common in XFS/XFG vs controls (P-for trend ≤0.0001) and in POAG vs controls (P-for trend ≤0.01). For each 100 capillaries, the number of hemorrhages was similar (P-for trend=0.91) between XFS/XFG and POAG patients; however, there were more avascular zones per 100 capillaries with borderline significance (P-for trend=0.04) in the XFS/XFG group. XFS/XFG patients had more tortuosity than POAG patients; specifically, having a tortuosity score ≥1.5 was associated with a 4.4-fold increased odds of XFS/XFG (95% confidence interval: 1.5-13.3) relative to a tortuosity score <1.0 (P-for trend=0.005).ConclusionA high degree of nailfold capillary tortuosity is a distinct non-ocular feature associated with XFS/XFG compared with either POAG or controls.


Asunto(s)
Capilares/diagnóstico por imagen , Síndrome de Exfoliación/diagnóstico , Microcirculación/fisiología , Uñas/irrigación sanguínea , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Síndrome de Exfoliación/fisiopatología , Femenino , Glaucoma de Ángulo Abierto/diagnóstico , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Masculino , Angioscopía Microscópica , Microscopía por Video , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
3.
Genet Mol Res ; 14(2): 4505-12, 2015 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-25966223

RESUMEN

Lung cancer is a complex polygenic disease and many genetic factors are involved in the development of the disease. As one of the most important and widely studied families of microRNA, let-7 appears to play an important role in initiation and progression of lung cancer. Any small changes in miRNA level or its target point can cause significant changes in gene function. In this study, we examined whether a single-nucleotide polymorphism in the promoter region of the let-7 family (rs10877887) is associated with the susceptibility to and prognosis of lung adenocarcinoma cancer. A hospital-based case-control research model was used in our study. The single-nucleotide polymorphism was genotyped in 69 lung cancer patients and 75 healthy controls by direct sequencing. The correlation between rs10877887 genotypes and the susceptibility to lung cancer was evaluated using an unconditional logistic regression model. Populations with the CT+CC genotype had a significantly increased AC risk compared to those with the TT genotype (CT+CC vs TT: P = 0.043, OR = 2.032, 95%CI = 1.018-4.054). Furthermore, the risk effect was greater in subgroups of females over 60 years old (CT+CC vs TT: OR = 6.857, 95%CI = 1.425-33.008, P = 0.012), and the C allele were confirmed to be a risk factor related to lung cancer in these females (P = 0.012). The single-nucleotide polymorphism rs10877887 in the promoter region of the let-7 family was found to be responsible for the susceptibility to lung adenocarcinoma cancer in Chinese individuals. This association was significantly stronger in females who were more than 60 years old.


Asunto(s)
Adenocarcinoma/genética , Predisposición Genética a la Enfermedad , Neoplasias Pulmonares/genética , MicroARNs/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Adenocarcinoma del Pulmón , Anciano , Pueblo Asiatico/genética , Estudios de Casos y Controles , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Familia de Multigenes , Factores de Riesgo
4.
Eye (Lond) ; 26(8): 1122-30, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22678051

RESUMEN

PURPOSE: To examine the effects of caffeinated coffee consumption on intraocular pressure (IOP), ocular perfusion pressure (OPP), and ocular pulse amplitude (OPA) in those with or at risk for primary open-angle glaucoma (POAG). METHODS: We conducted a prospective, double-masked, crossover, randomized controlled trial with 106 subjects: 22 with high tension POAG, 18 with normal tension POAG, 20 with ocular hypertension, 21 POAG suspects, and 25 healthy participants. Subjects ingested either 237 ml of caffeinated (182 mg caffeine) or decaffeinated (4 mg caffeine) coffee for the first visit and the alternate beverage for the second visit. Blood pressure (BP) and pascal dynamic contour tonometer measurements of IOP, OPA, and heart rate were measured before and at 60 and 90 min after coffee ingestion per visit. OPP was calculated from BP and IOP measurements. Results were analysed using paired t-tests. Multivariable models assessed determinants of IOP, OPP, and OPA changes. RESULTS: There were no significant differences in baseline IOP, OPP, and OPA between the caffeinated and decaffeinated visits. After caffeinated as compared with decaffeinated coffee ingestion, mean mm Hg changes (± SD) in IOP, OPP, and OPA were as follows: 0.99 (± 1.52, P<0.0001), 1.57 (± 6.40, P=0.0129), and 0.23 (± 0.52, P<0.0001) at 60 min, respectively; and 1.06 (± 1.67, P<0.0001), 1.26 (± 6.23, P=0.0398), and 0.18 (± 0.52, P=0.0006) at 90 min, respectively. Regression analyses revealed sporadic and inconsistent associations with IOP, OPP, and OPA changes. CONCLUSION: Consuming one cup of caffeinated coffee (182 mg caffeine) statistically increases, but likely does not clinically impact, IOP and OPP in those with or at risk for POAG.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Cafeína/efectos adversos , Estimulantes del Sistema Nervioso Central/efectos adversos , Café/efectos adversos , Glaucoma de Ángulo Abierto/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Presión Intraocular/efectos de los fármacos , Adulto , Anciano , Anciano de 80 o más Años , Bebidas , Estudios Cruzados , Método Doble Ciego , Femenino , Gonioscopía , Humanos , Masculino , Persona de Mediana Edad , Hipertensión Ocular/fisiopatología , Estudios Prospectivos , Tonometría Ocular
5.
Appl Opt ; 34(21): 4266-8, 1995 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-21052255

RESUMEN

The magneto-optic Q-switched operation of a neodymium-doped bismuth germinate crystal (Nd:BGO) laser that is end pumped by a cw 500-mW laser diode is reported. The crystal is a new host for Nd lasers. Here it acts as a magneto-optic modulator as well as a laser medium. A pulse energy of 2 µJ with a FWHM of 100 ns has been obtained. The device operates at a repetition rate of 1 kHz, and the fluctuation of the shot-to-shot intensity is less than ±1%.

6.
Shanghai Kou Qiang Yi Xue ; 3(2): 90-1, 1994 Jun.
Artículo en Chino | MEDLINE | ID: mdl-15160150

RESUMEN

The four enamel pieces,which are from one bovine tooth,are treated individually by 2.7% NaF gel(pH4),2.7% NaF gel(pH7),1%NaF gel (pH7.0) and the control group gel.The fluoride amount in enamel pieces is measured by fluoride electrode.The aim of present study is to observe the changer of enamel intake of fluoride amount when the pH and fluoride concentration varies.In results the most fluoride amount in enamel pieces treated by 2.7% NaF gel(pH4) is measured.The more fluoride amount is measured in group of 2.7%NaF gel(pH7) than 1% NaF gel (pH7).The Results show lower pH and higher fluoride concentration can increase more fluoride amount in enamel.

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