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1.
IEEE Trans Pattern Anal Mach Intell ; 45(2): 2492-2504, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35254978

RESUMEN

The growth of videos in our digital age and the users' limited time raise the demand for processing untrimmed videos to produce shorter versions conveying the same information. Despite the remarkable progress that summarization methods have made, most of them can only select a few frames or skims, creating visual gaps and breaking the video context. This paper presents a novel weakly-supervised methodology based on a reinforcement learning formulation to accelerate instructional videos using text. A novel joint reward function guides our agent to select which frames to remove and reduce the input video to a target length without creating gaps in the final video. We also propose the Extended Visually-guided Document Attention Network (VDAN+), which can generate a highly discriminative embedding space to represent both textual and visual data. Our experiments show that our method achieves the best performance in Precision, Recall, and F1 Score against the baselines while effectively controlling the video's output length.

2.
Lymphology ; 55(3): 129-134, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36446400

RESUMEN

We have studied the lymphatic phenotypes of 2 mutations, known to cause abnormalities of lymphatics in humans, in mice. The Cx47 R260C mutation (variably penetrant in humans heterozygous for it and causing limb lymphedema) had an adult mouse phenotype of hyperplasia and increased lymph nodes only in homozygous condition but we did not find any anatomical phenotype in day 16.5 homozygous embryos. Mice harboring the Sos1 mutation E846K (causing Noonan's in man which occasionally shows lymphatic dysplasia) had no adult heterozygous phenotype in lymphatic vessel appearance and drainage (homozygotes are early embryonic lethals) while day 16.5 heterozygous embryos also had no detectable anatomical phenotype.


Asunto(s)
Enfermedades Linfáticas , Vasos Linfáticos , Proteína SOS1 , Animales , Humanos , Ratones , Heterocigoto , Homocigoto , Vasos Linfáticos/anomalías , Vasos Linfáticos/embriología , Mutación , Fenotipo , Linfedema/embriología , Linfedema/genética , Enfermedades Linfáticas/embriología , Enfermedades Linfáticas/genética , Proteína SOS1/genética , Conexinas/genética
3.
Lymphology ; 55(1): 33-35, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35896113

RESUMEN

A recent genome-wide association study (GWAS) looking for the genes determining fingerprint and palmar crease patterns disclosed one gene, among many others, which causes lymphedema (CELSR1) while others influencing tissue growth. Since digital fluid influences the height of the volar pads, influences of lymphedema on dermatoglyphics should be sought.


Asunto(s)
Dermatoglifia , Linfedema , Estudio de Asociación del Genoma Completo , Humanos , Linfedema/diagnóstico , Linfedema/genética , Piel
4.
Lymphology ; 55(4): 141-143, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-37553002

RESUMEN

New findings reopen the controversy about centrifugal vs. centripetal origin of the lymphatic system and support that the latter may be the predominant source of lymphatic endothelial cells from mesenchymal lymphangioblasts.

5.
Lymphology ; 54(2): 78-91, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34735753

RESUMEN

Connexin proteins form gap junctions controlling exchange of ions and small molecules between cells and play an important role in movement of lymph within lymphatic vessels. Connexin47 (CX47) is highly expressed in lymphatic endothelial cells and CX47 missense mutations, i.e., R260C, cosegregate with primary lymphedema in humans. However, studies utilizing CX47 knockout mice have failed to demonstrate any lymphatic anomalies. To unravel the lymphatic consequences of expressing a mutant CX47 protein, we used CRISPR technology to create a mouse carrying a Cx47 missense mutation (Cx47R259C) equivalent to the human CX47R260C missense mutation associated with human primary lymphedema. Intradermal Evans Blue dye injection identified a 2-fold increase in regional lymph nodes in homozygous Cx47R259C mice compared to wildtype, particularly in the jugular region (4.8 ± 0.4 and 2.0 ± 0.0, respectively, p<0.01). Associated lymphatic channels were increased in Cx47R259C mice and mesenteric lymph reflux occurred in homozygous Cx47R259C mice but not in wildtype. Contractility of superficial cervical lymphatics, assessed by pressure myography, was reduced in homozygous Cx47R259C mice compared to wildtype. In conclusion, our data are the first to demonstrate a role for the Cx47 protein in lymphatic anatomy and function. This phenotype is similar to that found with other valve deficient mouse mutants, e.g., in Foxc2. Of significance, this study is the first to use CRISPR technology to develop a pre-clinical model of primary lymphedema and demonstrates the importance of distinguishing between lack of and presence of mutant protein when developing clinically relevant animal models for translation of pre-clinical findings.


Asunto(s)
Vasos Linfáticos , Linfedema , Animales , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Conexinas/genética , Células Endoteliales/metabolismo , Células Endoteliales/patología , Humanos , Vasos Linfáticos/patología , Linfedema/patología , Ratones , Ratones Noqueados , Fenotipo , Mutación Puntual
7.
J Am Med Inform Assoc ; 28(9): 1834-1842, 2021 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-34279636

RESUMEN

OBJECTIVE: Rheumatic heart disease (RHD) affects an estimated 39 million people worldwide and is the most common acquired heart disease in children and young adults. Echocardiograms are the gold standard for diagnosis of RHD, but there is a shortage of skilled experts to allow widespread screenings for early detection and prevention of the disease progress. We propose an automated RHD diagnosis system that can help bridge this gap. MATERIALS AND METHODS: Experiments were conducted on a dataset with 11 646 echocardiography videos from 912 exams, obtained during screenings in underdeveloped areas of Brazil and Uganda. We address the challenges of RHD identification with a 3D convolutional neural network (C3D), comparing its performance with a 2D convolutional neural network (VGG16) that is commonly used in the echocardiogram literature. We also propose a supervised aggregation technique to combine video predictions into a single exam diagnosis. RESULTS: The proposed approach obtained an accuracy of 72.77% for exam diagnosis. The results for the C3D were significantly better than the ones obtained by the VGG16 network for videos, showing the importance of considering the temporal information during the diagnostic. The proposed aggregation model showed significantly better accuracy than the majority voting strategy and also appears to be capable of capturing underlying biases in the neural network output distribution, balancing them for a more correct diagnosis. CONCLUSION: Automatic diagnosis of echo-detected RHD is feasible and, with further research, has the potential to reduce the workload of experts, enabling the implementation of more widespread screening programs worldwide.


Asunto(s)
Aprendizaje Profundo , Cardiopatía Reumática , Niño , Diagnóstico Precoz , Ecocardiografía , Humanos , Tamizaje Masivo , Cardiopatía Reumática/diagnóstico por imagen , Adulto Joven
8.
Lymphology ; 54(4): 167-169, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35073620

RESUMEN

We have created a human chromosomal map of the location of known and candidate genes involved in primary lymphedema (PLE). This should facilitate further discovery and provide a basis for understanding microdeletions which cause lymphedema.


Asunto(s)
Linfangiogénesis , Linfedema , Cromosomas Humanos , Humanos , Linfangiogénesis/genética , Linfedema/genética
9.
IEEE Trans Pattern Anal Mach Intell ; 43(4): 1438-1444, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32248095

RESUMEN

Technological advances in sensors have paved the way for digital cameras to become increasingly ubiquitous, which, in turn, led to the popularity of the self-recording culture. As a result, the amount of visual data on the Internet is moving in the opposite direction of the available time and patience of the users. Thus, most of the uploaded videos are doomed to be forgotten and unwatched stashed away in some computer folder or website. In this paper, we address the problem of creating smooth fast-forward videos without losing the relevant content. We present a new adaptive frame selection formulated as a weighted minimum reconstruction problem. Using a smoothing frame transition and filling visual gaps between segments, our approach accelerates first-person videos emphasizing the relevant segments and avoids visual discontinuities. Experiments conducted on controlled videos and also on an unconstrained dataset of First-Person Videos (FPVs) show that, when creating fast-forward videos, our method is able to retain as much relevant information and smoothness as the state-of-the-art techniques, but in less processing time.

10.
Ecol Appl ; 29(6): e01951, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31188494

RESUMEN

Natural resource managers use data on the spatial range of species to guide management decisions. These data come from survey or monitoring efforts that use a wide variety of tools. Environmental DNA (eDNA) is a surveillance tool that uses genetic markers for detecting species and holds potential as a tool for large-scale monitoring programs. Two challenges of eDNA-based studies are uncertainties created by imperfect capture of eDNA in collection samples (e.g., water field samples) and imperfect detection of eDNA using molecular methods (e.g., quantitative PCR). Occurrence models can be used to address these challenges, thus we use an occurrence model to address two objectives: first, to determine how many samples were required to detect species using eDNA; second, to examine when and where to take samples. We collected water samples from three different habitat types in the Upper Mississippi River when both Bighead Carp and Silver Carp were known to be present based on telemetry detections. Each habitat type (backwater, tributary, and impoundment) was sampled during April, May, and November. Detections of eDNA for both species varied across sites and months, but were generally low, 0-19.3% of samples were positive for eDNA. Overall, we found that eDNA-based sampling holds promise to be a powerful monitoring tool for resource managers; however, limitations of eDNA-based sampling include different biological and ecological characteristics of target species such as seasonal habitat usage patterns as well as aspects of different physical environments that impact the implementation of these methods such as water temperature.


Asunto(s)
Carpas , Ecosistema , Animales , Ecología , Mississippi , Ríos
11.
Lymphology ; 51(2): 85-88, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30253460

RESUMEN

We performed whole exome sequencing in a family with FOXC2 mutation where the phenotype in one generation was strikingly more severe. Although there were 3 mutations shared by 2 fatal fetal hydrops cases and not the mildly affected mother, none of them were likely to be the cause of the marked phenotypic change.


Asunto(s)
Factores de Transcripción Forkhead/genética , Genes Modificadores , Hidropesía Fetal/genética , Linfedema/genética , Mutación , Factores de Edad , Edad de Inicio , Perfilación de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Hidropesía Fetal/diagnóstico , Lactante , Recién Nacido , Linfedema/diagnóstico , Linaje , Fenotipo , Polimorfismo de Nucleótido Simple , Secuenciación del Exoma
12.
Aliment Pharmacol Ther ; 47(11): 1440-1452, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29601644

RESUMEN

BACKGROUND: Novel treatments with superior benefit-risk profiles are needed to improve the long-term prognosis of patients with inflammatory bowel disease (IBD). Etrolizumab-a monoclonal antibody that specifically targets ß7 integrins-is currently under phase III clinical evaluation in IBD. AIM: This review summarises the available pharmacological and pharmacokinetic/pharmacodynamic data for etrolizumab to provide a comprehensive understanding of its mechanism of action (MOA) and pharmacological effects. METHODS: Published and internal unpublished data from nonclinical and clinical studies with etrolizumab are reviewed. RESULTS: Etrolizumab exerts its effect via a unique dual MOA that inhibits both leucocyte trafficking to the intestinal mucosa and retention within the intestinal epithelial layer. The gut-selectivity of etrolizumab results from its specific targeting of the ß7 subunit of α4ß7 and αEß7 integrins. Etrolizumab does not bind to α4ß1 integrin, which mediates lymphocyte trafficking to tissues including the central nervous system, a characteristic underlying its favourable safety with regard to progressive multifocal leucoencephalopathy. Phase I/II studies in patients with ulcerative colitis (UC) showed linear pharmacokinetics when etrolizumab was administered subcutaneously at 100 mg or higher once every 4 weeks. This dose was sufficient to enable full ß7 receptor occupancy in both blood and intestinal tissues of patients with moderate to severe UC. The phase II study results also suggested that patients with elevated intestinal expression of αE integrin may have an increased likelihood of clinical remission in response to etrolizumab treatment. CONCLUSION: Etrolizumab is a gut-selective, anti-ß7 integrin monoclonal antibody that may have therapeutic potential for the treatment of IBD.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacocinética , Fármacos Gastrointestinales/farmacocinética , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/metabolismo , Cadenas beta de Integrinas/metabolismo , Animales , Anticuerpos Monoclonales Humanizados/uso terapéutico , Ensayos Clínicos como Asunto/métodos , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Fármacos Gastrointestinales/uso terapéutico , Humanos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo
13.
Sensors (Basel) ; 16(12)2016 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-27929424

RESUMEN

In this paper, we present a monocular vision-based height estimation algorithm for terrain following flights. The impressive growth of Unmanned Aerial Vehicle (UAV) usage, notably in mapping applications, will soon require the creation of new technologies to enable these systems to better perceive their surroundings. Specifically, we chose to tackle the terrain following problem, as it is still unresolved for consumer available systems. Virtually every mapping aircraft carries a camera; therefore, we chose to exploit this in order to use presently available hardware to extract the height information toward performing terrain following flights. The proposed methodology consists of using optical flow to track features from videos obtained by the UAV, as well as its motion information to estimate the flying height. To determine if the height estimation is reliable, we trained a decision tree that takes the optical flow information as input and classifies whether the output is trustworthy or not. The classifier achieved accuracies of 80 % for positives and 90 % for negatives, while the height estimation algorithm presented good accuracy.

14.
Oper Dent ; 41(5): 520-530, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27351078

RESUMEN

The purpose of this study was to determine the enamel bond durability of three universal adhesives in different etching modes through fatigue testing. The three universal adhesives used were Scotchbond Universal, Prime&Bond Elect universal dental adhesive, and All-Bond Universal light-cured dental adhesive. A single-step self-etch adhesive, Clearfil S3 Bond Plus was used as a control. The shear bond strength (SBS) and shear fatigue strength (SFS) to human enamel were evaluated in total-etch mode and self-etch mode. A stainless steel metal ring with an internal diameter of 2.4 mm was used to bond the resin composite to the flat-ground (4000-grit) tooth surfaces for determination of both SBS and SFS. For each enamel surface treatment, 15 specimens were prepared for SBS and 30 specimens for SFS. The staircase method for fatigue testing was then used to determine the SFS of the resin composite bonded to the enamel using 10-Hz frequencies for 50,000 cycles or until failure occurred. Scanning electron microscopy was used to observe representative debonded specimen surfaces and the resin-enamel interfaces. A two-way analysis of variance and the Tukey post hoc test were used for analysis of the SBS data, whereas a modified t-test with Bonferroni correction was used for the SFS data. All adhesives in total-etch mode showed significantly higher SBS and SFS values than those in self-etch mode. Although All-Bond Universal in self-etch mode showed a significantly lower SBS value than the other adhesives, there was no significant difference in SFS values among the adhesives in this mode. All adhesives showed higher SFS:SBS ratios in total-etch mode than in self-etch mode. With regard to the adhesive systems used in this study, universal adhesives showed higher enamel bond strengths in total-etch mode. Although the influence of different etching modes on the enamel-bonding performance of universal adhesives was found to be dependent on the adhesive material, total-etch mode effectively increased the enamel bond strength and durability, as measured by fatigue testing.

15.
Appl Phys Lett ; 1082016.
Artículo en Inglés | MEDLINE | ID: mdl-27114615

RESUMEN

We have fabricated a wide-bandwidth, high dynamic range, low-noise cryogenic amplifier based on a superconducting kinetic inductance traveling-wave device. The device was made from NbTiN and consisted of a long, coplanar waveguide on a silicon chip. By adding a DC current and an RF pump tone we are able to generate parametric amplification using three-wave mixing. The devices exhibit gain of more than 15 dB across an instantaneous bandwidth from 4 to 8 GHz. The total usable gain bandwidth, including both sides of the signal-idler gain region, is more than 6 GHz. The noise referred to the input of the devices approaches the quantum limit, with less than 1 photon excess noise. Compared to similarly constructed four-wave mixing amplifiers, these devices operate with the RF pump at ~20 dB lower power and at frequencies far from the signal. This will permit easier integration into large scale qubit and detector applications.

16.
IEEE Comput Graph Appl ; 36(2): 24-35, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26960026

RESUMEN

In underwater environments, the scattering and absorption phenomena affect the propagation of light, degrading the quality of captured images. In this work, the authors present a method based on a physical model of light propagation that takes into account the most significant effects to image degradation: absorption, scattering, and backscattering. The proposed method uses statistical priors to restore the visual quality of the images acquired in typical underwater scenarios.

17.
Oper Dent ; 40(4): 379-95, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25706611

RESUMEN

The purpose of this study was to use shear bond strength (SBS) and shear fatigue limit (SFL) testing to determine the effect of phosphoric acid pre-etching of enamel and dentin prior to application of self-etch adhesives for bonding resin composite to these substrates. Three self-etch adhesives--1) G- ænial Bond (GC Corporation, Tokyo, Japan); 2) OptiBond XTR (Kerr Corp, Orange, CA, USA); and 3) Scotchbond Universal (3M ESPE Dental Products, St Paul, MN, USA)--were used to bond Z100 Restorative resin composite to enamel and dentin surfaces. A stainless-steel metal ring with an inner diameter of 2.4 mm was used to bond the resin composite to flat-ground (4000 grit) tooth surfaces for determination of both SBS and SFL. Fifteen specimens each were used to determine initial SBS to human enamel/dentin, with and without pre-etching with a 35% phosphoric acid (Ultra-Etch, Ultradent Products Inc, South Jordan, UT, USA) for 15 seconds prior to the application of the adhesives. A staircase method of fatigue testing (25 specimens for each test) was then used to determine the SFL of resin composite bonded to enamel/dentin using a frequency of 10 Hz for 50,000 cycles or until failure occurred. A two-way analysis of variance and Tukey post hoc test were used for analysis of SBS data, and a modified t-test with Bonferroni correction was used for the SFL data. Scanning electron microscopy was used to examine the area of the bonded restorative/tooth interface. For all three adhesive systems, phosphoric acid pre-etching of enamel demonstrated significantly higher (p<0.05) SBS and SFL with pre-etching than it did without pre-etching. The SBS and SFL of dentin bonds decreased with phosphoric acid pre-etching. The SBS and SFL of bonds using phosphoric acid prior to application of self-etching adhesives clearly demonstrated different tendencies between enamel and dentin. The effect of using phosphoric acid, prior to the application of the self-etching adhesives, on SBS and SFL was dependent on the adhesive material and tooth substrate and should be carefully considered in clinical situations.


Asunto(s)
Grabado Ácido Dental/métodos , Cementos Dentales , Ácidos Fosfóricos , Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/efectos de los fármacos , Análisis del Estrés Dental , Dentina/efectos de los fármacos , Humanos , Ensayo de Materiales , Ácidos Fosfóricos/farmacología , Resistencia al Corte
18.
Oper Dent ; 40(3): 322-35, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25706614

RESUMEN

A laboratory study was conducted to examine the wear of resin composite materials using both a localized and generalized wear simulation model. Twenty specimens each of seven resin composites (Esthet•X HD [HD], Filtek Supreme Ultra [SU], Herculite Ultra [HU], SonicFill [SF], Tetric EvoCeram Bulk Fill [TB], Venus Diamond [VD], and Z100 Restorative [Z]) were subjected to a wear challenge of 400,000 cycles for both localized and generalized wear in a Leinfelder-Suzuki wear simulator (Alabama machine). The materials were placed in custom cylinder-shaped stainless steel fixtures. A stainless steel ball bearing (r=2.387 mm) was used as the antagonist for localized wear, and a stainless steel, cylindrical antagonist with a flat tip was used for generalized wear. A water slurry of polymethylmethacrylate (PMMA) beads was used as the abrasive media. A noncontact profilometer (Proscan 2100) with Proscan software was used to digitize the surface contours of the pretest and posttest specimens. AnSur 3D software was used for wear assessment. For localized testing, maximum facet depth (µm) and volume loss (mm(3)) were used to compare the materials. The mean depth of the facet surface (µm) and volume loss (mm(3)) were used for comparison of the generalized wear specimens. A one-way analysis of variance (ANOVA) and Tukey post hoc test were used for data analysis of volume loss for both localized and generalized wear, maximum facet depth for localized wear, and mean depth of the facet for generalized wear. The results for localized wear simulation were as follows [mean (standard deviation)]: maximum facet depth (µm)--Z, 59.5 (14.7); HU, 99.3 (16.3); SU, 102.8 (13.8); HD, 110.2 (13.3); VD, 114.0 (10.3); TB, 125.5 (12.1); SF, 195.9 (16.9); volume loss (mm(3))--Z, 0.013 (0.002); SU, 0.026 (0.006); HU, 0.043 (0.008); VD, 0.057 (0.009); HD, 0.058 (0.014); TB, 0.061 (0.010); SF, 0.135 (0.024). Generalized wear simulation results were as follows: mean depth of facet (µm)--Z, 9.3 (3.4); SU, 12.8 (3.1); HU, 15.6 (3.2); TB, 19.2 (4.8); HD, 26.8 (6.5); VD, 29.1 (5.5); SF, 35.6 (8.4); volume loss (mm(3))--Z, 0.132 (0.049); SU, 0.0179 (0.042); HU, 0.224 (0.044); TB, 0.274 (0.065); HD, 0.386 (0.101); VD, 0.417 (0.076); SF, 0.505 (0.105). The ANOVA showed a significant difference among materials (p<0.001) for facet depth and volume loss for both localized and generalized wear. The post hoc test revealed differences (p<0.05) in localized and generalized wear values among the seven resin composites examined in this study. The findings provide valuable information regarding the relative wear characteristics of the materials in this study.


Asunto(s)
Resinas Compuestas/uso terapéutico , Alisadura de la Restauración Dental , Resinas Compuestas/normas , Humanos , Microscopía Electrónica de Rastreo , Dióxido de Silicio/normas , Dióxido de Silicio/uso terapéutico , Circonio/normas , Circonio/uso terapéutico
19.
Oper Dent ; 40(6): 603-13, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25405905

RESUMEN

The purpose of this study was to determine flexural properties and erosive wear behavior of provisional resin materials. Three bis-acryl base provisional resins-1) Protemp Plus (PP), 2) Integrity (IG), 3) Luxatemp Automix Plus (LX)-and a conventional poly(methylmethacrylate) (PMMA) resin, UniFast III (UF), were evaluated. A resin composite, Z100 Restorative (Z1), was included as a benchmark material. Six specimens for each of the four materials were used to determine flexural strength and elastic modulus according to ISO Standard 4049. Twelve specimens for each material were used to examine wear using a generalized wear simulation model. The test materials were each subjected to wear challenges of 25,000, 50,000, 100,000, and 200,000 cycles in a Leinfelder-Suzuki (Alabama) wear simulator. The materials were placed in custom cylinder-shaped stainless-steel fixtures, and wear was generated using a cylindrical-shaped flat-ended stainless-steel antagonist in a slurry of nonplasticized PMMA beads. Wear (mean facet depth [µm] and volume loss [mm(3)]) was determined using a noncontact profilometer (Proscan 2100) with Proscan and AnSur 3D software. The laboratory data were evaluated using two-way analysis of variance (ANOVA; factors: 1) material and 2) cycles) followed by Tukey HSD post hoc test (α=0.05). The flexural strength ranged from 68.2 to 150.6 MPa, and the elastic modulus ranged from 2.0 to 15.9 GPa. All of the bis-acryl provisional resins (PP, IG, and LX) demonstrated significantly higher values than the PMMA resin (UF) in flexural strength and elastic modulus (p<0.05). However, there was no significant difference (p>0.05) in flexural properties among three bis-acryl base provisional resins (PP, IG, and LX). Z1 demonstrated significantly (p<0.05) higher flexural strength and elastic modulus than the other materials tested. The results for mean facet wear depth (µm) and standard deviations (SD) for 200,000 cycles were as follows: PP, 22.4 (5.0); IG, 51.0 (6.5); LX, 63.7 (4.5); UF, 70.5 (8.0); and Z1, 7.6 (1.2). Volume loss (mm(3)) and SDs for 200,000 cycles were as follows: PP, 0.311 (0.049); IG, 0.737 (0.074); LX, 0.919 (0.053); UF, 1.046 (0.127); and Z1, 0.111 (0.017). The two-way ANOVA showed a significant difference among materials (p<0.001) and number of cycles for both facet depth and volume loss. The post hoc test revealed differences (p<0.05) in wear values among the tested materials examined in this study. The findings provide valuable information regarding the flexural properties and the relative wear behavior of the provisional resins examined in this study.


Asunto(s)
Resinas Acrílicas/química , Bisfenol A Glicidil Metacrilato/química , Resinas Compuestas/química , Alisadura de la Restauración Dental , Análisis del Estrés Dental , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Docilidad , Polimetil Metacrilato/química , Propiedades de Superficie
20.
Phys Rev Lett ; 113(18): 187002, 2014 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-25396390

RESUMEN

We have generated frequency combs spanning 0.5 to 20 GHz in superconducting λ/2 resonators at T=3 K. Thin films of niobium-titanium nitride enabled this development due to their low loss, high nonlinearity, low frequency dispersion, and high critical temperature. The combs nucleate as sidebands around multiples of the pump frequency. Selection rules for the allowed frequency emission are calculated using perturbation theory, and the measured spectrum is shown to agree with the theory. Sideband spacing is measured to be accurate to 1 part in 10(8). The sidebands coalesce into a continuous comb structure observed to cover at least several frequency octaves.

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