Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 118(49)2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34845017

RESUMO

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here, we analyze functional recovery using community data on seven plant characteristics (traits) of 1,016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits, we enhance understanding of the mechanisms of succession, assess ecosystem recovery, and use these insights to propose successful forest restoration strategies. Wet and dry forests diverged markedly for several traits that increase growth rate in wet forests but come at the expense of reduced drought tolerance, delay, or avoidance, which is important in seasonally dry forests. Dry and wet forests showed different successional pathways for several traits. In dry forests, species turnover is driven by drought tolerance traits that are important early in succession and in wet forests by shade tolerance traits that are important later in succession. In both forests, deciduous and compound-leaved trees decreased with forest age, probably because microclimatic conditions became less hot and dry. Our results suggest that climatic water availability drives functional recovery by influencing the start and trajectory of succession, resulting in a convergence of community trait values with forest age when vegetation cover builds up. Within plots, the range in functional trait values increased with age. Based on the observed successional trait changes, we indicate the consequences for carbon and nutrient cycling and propose an ecologically sound strategy to improve forest restoration success.


Assuntos
Conservação dos Recursos Naturais , Florestas , Modelos Biológicos , Clima Tropical
2.
Clin Oral Investig ; 28(6): 336, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38795258

RESUMO

OBJECTIVE: Stress distribution assessment by finite elements analysis in poly(etheretherketone) (PEEK) implant and abutment as retainers of single crowns in the anterior region. MATERIALS AND METHODS: Five 3D models were created, varying implant/abutment manufacturing materials: titanium (Ti), zirconia (Zr), pure PEEK (PEEKp), carbon fiber-reinforced PEEK (PEEKc), glass fiber-reinforced PEEK (PEEKg). A 50 N load was applied 30o off-axis at the incisal edge of the upper central incisor. The Von Mises stress (σvM) was evaluated on abutment, implant/screw, and minimum principal stress (σmin) and maximum shear stress (τmax) for cortical and cancellous bone. RESULTS: The abutment σvM lowest stress was observed in PEEKp group, being 70% lower than Ti and 74% than Zr. On the implant, PEEKp reduced 68% compared to Ti and a 71% to Zr. In the abutment screws, an increase of at least 33% was found in PEEKc compared to Ti, and of at least 81% to Zr. For cortical bone, the highest τmax values were in the PEEKp group, and a slight increase in stress was observed compared to all PEEK groups with Ti and Zr. For σmin, the highest stress was found in the PEEKc. Stress increased at least 7% in cancellous bone for all PEEK groups. CONCLUSION: Abutments and implants made by PEEKc concentrate less σvM stress, transmitting greater stress to the cortical and medullary bone. CLINICAL RELEVANCE: The best stress distribution in PEEKc components may contribute to decreased stress shielding; in vitro and in vivo research is recommended to investigate this.


Assuntos
Benzofenonas , Coroas , Dente Suporte , Análise do Estresse Dentário , Análise de Elementos Finitos , Cetonas , Teste de Materiais , Polietilenoglicóis , Polímeros , Titânio , Zircônio , Cetonas/química , Polietilenoglicóis/química , Humanos , Zircônio/química , Titânio/química , Fibra de Carbono/química , Projeto do Implante Dentário-Pivô , Incisivo , Materiais Dentários/química , Implantes Dentários para Um Único Dente , Osso Cortical , Vidro/química , Planejamento de Prótese Dentária
3.
Molecules ; 29(14)2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39065006

RESUMO

Inulin is a carbohydrate that belongs to fructans; due to its health benefits, it is widely used in the food and pharmaceutical industries. In this research, cabuya (Agave americana) was employed to obtain inulin by pulsed electric field-assisted extraction (PEFAE) and FTIR analysis confirmed its presence. The influence of PEFAE operating parameters, namely, electric field strength (1, 3 and 5 kV/cm), pulse duration (0.1, 0.2 and 0.5 ms), number of pulses (10,000, 20,000 and 40,000) and work cycle (20, 50 and 80%) on the permeabilization index and energy expenditure were tested. Also, once the operating conditions for PEFAE were set, the temperature for conventional extraction (CE) and PEFAE were defined by comparing extraction kinetics. The cabuya meristem slices were exposed to PEFAE to obtain extracts that were quantified, purified and concentrated. The inulin was isolated by fractional precipitation with ethanol to be characterized. The highest permeabilization index and the lowest energy consumption were reached at 5 kV/cm, 0.5 ms, 10,000 pulses and 20%. The same extraction yield and approximately the same amount of inulin were obtained by PEFAE at 60 °C compared to CE at 80 °C. Despite, the lower amount of inulin obtained by PEFAE in comparison to CE, its quality was better because it is mainly constituted of inulin of high average polymerization degree with more than 38 fructose units. In addition, TGA analyses showed that inulin obtained by PEFAE has a lower thermal degradation rate than the obtained by CE and to the standard.


Assuntos
Agave , Inulina , Inulina/química , Inulina/isolamento & purificação , Agave/química , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade , Temperatura
4.
J Prosthet Dent ; 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36841707

RESUMO

STATEMENT OF PROBLEM: Rehabilitation with wide-diameter reduced-length implants has become popular for patients with minimal vertical bone. However, a consensus on the benefits of this approach is lacking. PURPOSE: The purpose of this systematic review with meta-analysis was to evaluate the influence of wide compared with regular diameter on the clinical performance of short (<10 mm) and extrashort (≤6 mm) dental implants used for rehabilitations with single crowns, fixed partial dentures, or both, in the posterior region. MATERIAL AND METHODS: A search in 6 databases was conducted to select randomized controlled trials (RCTs) and nonrandomized controlled trials (N-RCTs). Five meta-analyses were performed, where the risk ratio (RR) was evaluated. The certainty of evidence was evaluated, and the risk of bias was determined from the Joanna Briggs Institute checklist. RESULTS: Fourteen articles were included, 272 wide- and 478 regular-diameter implants. One study presented a low, 3 an unclear, and 11 a high risk of bias. Meta-analyses showed no statistical difference: implant survival, short dental implants in N-RCTs (up to 1 year - RR 1.01 [0.98; 1.03], 1 to 5 years - RR 1.01 [0.94; 1.08], more than 5 years - RR 1.01 [0.97; 1.06]), extrashort dental implants in N-RCTs (RR 1.04 [0.90; 1.20]), RCTs (RR 1.05 [0.88; 1.25]); implant success in N-RCTs (RR 1.01 [0.97; 1.05]); prosthesis success in N-RCTs (RR 1.01 [0.97; 1.05]). CONCLUSIONS: Short and extrashort dental implants with a wide and regular diameter appear to be clinically appropriate options for implant-supported posterior restorations, with high survival, success, and prosthesis success rates.

5.
J Prosthet Dent ; 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35864024

RESUMO

STATEMENT OF PROBLEM: Implant-supported single crowns are more prone to screw loosening than splinted prostheses. Therefore, the locking taper system, which has a screwless abutment, may perform better when associated with this type of rehabilitation. However, systematic reviews on this system are lacking. PURPOSE: The purpose of this systematic review was to evaluate the clinical performance and complications of single crowns retained by the locking taper system. MATERIAL AND METHODS: This systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under CRD42020189921. An electronic search was made in 5 databases and 3 other sources up to February 2021 to select prospective clinical studies evaluating the performance of single crowns retained by the locking taper system by using the outcomes implant survival, success rate, complications, marginal bone loss (MBL), and prosthesis success rate. Four meta-analyses grouped according to the follow-up intervals were performed. The risk of bias of the selected studies was evaluated by using the RoB 2 checklist for randomized controlled trials (RCTs) and Downs and Black for uncontrolled studies. RESULTS: Twelve studies were included: 9 prospective cohort studies and 3 RCTs. A survival rate of 99% (98% to 99%) and a success rate of 97% (92% to 99%) after 5 years were found. Of the total, 2.6% biological and 2.9% prosthetic complications were described. The prosthesis success rate was 97% (96% to 98%) after 5 years. An average of -0.73 mm (-0.93 to -0.52) was found for the MBL after 5 years. The risk-of-bias assessment showed 2 RCTs with high risk and 1 RCT with low risk of bias. Among uncontrolled studies, 2 were classified as poor and 7 as fair. CONCLUSIONS: Single crowns retained by locking taper implants can be safely indicated based on the high survival and success rates achieved in the long term, the maintenance of bone level stability over time, and the low incidence of complications.

6.
J Prosthet Dent ; 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35931572

RESUMO

STATEMENT OF PROBLEM: Evidence regarding the retention system for a mandibular overdenture is important for treatment planning. However, the clinical performance of stud and ball attachments for mandibular overdenture retainers is unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to compare the clinical performance and self-reported patient outcomes of ball and stud attachments as mandibular overdenture retainers. MATERIAL AND METHODS: Randomized (RCTs) and nonrandomized (N-RCTs) controlled clinical trials were selected based on the eligibility criteria. The risk of bias was assessed by using the Cochrane Collaboration Tools, and the certainty of the evidence (COE) by using the grades of recommendation, assessment, development, and evaluation (GRADE) workshop approach. Meta-analyses according to the follow-up period were performed for implant survival, prosthetic maintenance and complications, bleeding on probing (BoP), marginal bone loss (MBL), satisfaction, and oral health-related quality of life (OHRQoL). RESULTS: Thirteen RCTs and 4 N-RCTs were included. Twelve studies presented a high risk of bias. The stud demonstrated a lower risk ratio (RR) (P<.001) for maintenance and complications concerning the need for matrix activation (RR 7.12 [2.65, 19.15]) (very low COE) and new overdentures (RR 2.47 [1.02, 5.96]) (moderate COE), ranging from 1 to 5 years of follow-up. Mean difference (MD) for MBL after 1 (MD 0.40 [0.28, 0.52]; P<.001) and 5 years (MD 0.18 [0.16, 0.20]; P<.001) was higher for ball attachments than that for stud (very low COE) attachments. Stud attachments also improved satisfaction (P<.001) when compared with ball attachments (very low COE). Implant survival rate (high COE), BoP (very low COE), and OHRQoL (low COE) were similar for the attachments. CONCLUSIONS: Stud and ball attachments are clinically appropriate options as mandibular overdenture retainers and are capable of restoring OHRQoL. Nevertheless, the stud showed greater improvement in satisfaction and less prosthetic aftercare and MBL.

7.
Molecules ; 27(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408511

RESUMO

The production and use of eco-friendly corrosion inhibitors allows valuable compounds contained in plant waste to be identified and repurposed while reducing the use of polluting synthetic substances. Pectin extracted from Tahiti limes (Citrus latifolia) and King mandarin (Citrus nobilis L.) in addition to natural gums-xanthan gum and latex from the "lechero" plant (Euphorbia laurifolia)-were used to create an eco-friendly corrosion inhibitor. The optimal extraction conditions for pectin were determined from different combinations of pH, temperature, and time in a 23 factorial design and evaluated according to the obtained pectin yield. The highest pectin extraction yields (38.10% and 41.20% from King mandarin and lime, respectively) were reached at pH = 1, 85 °C, and 2 h. Extraction of pectic compounds was confirmed using Fourier-transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry analyses. Subsequently, a simplex-centroid mixture design was applied to determine the formulation of extracted pectin and natural gums that achieved the highest corrosion inhibitor effect (linear polarization and weight loss methods in NACE 1D-196 saline media using API-5LX52 carbon steel). Impedance spectroscopy analysis showed that the addition of xanthan gum to pectin (formulation 50% pectin-50% xanthan gum) improved the corrosion inhibitor effect from 29.20 to 78.21% at 400 ppm due to higher adsorption of inhibitory molecules on the metal surface.


Assuntos
Citrus , Aço , Carbono/química , Corrosão , Equador , Pectinas/química , Aço/química
8.
Sensors (Basel) ; 21(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915879

RESUMO

Triathlon has become increasingly popular in recent years. In this discipline, maximum oxygen consumption (VO2max) is considered the gold standard for determining competition cardiovascular capacity. However, the emergence of wearable sensors (as Stryd) has drastically changed training and races, allowing for the more precise evaluation of athletes and study of many more potential determining variables. Thus, in order to discover factors associated with improved running efficiency, we studied which variables are correlated with increased speed. We then developed a methodology to identify associated running patterns that could allow each individual athlete to improve their performance. To achieve this, we developed a correlation matrix, implemented regression models, and created a heat map using hierarchical cluster analysis. This highlighted relationships between running patterns in groups of young triathlon athletes and several different variables. Among the most important conclusions, we found that high VO2max did not seem to be significantly correlated with faster speed. However, faster individuals did have higher power per kg, horizontal power, stride length, and running effectiveness, and lower ground contact time and form power ratio. VO2max appeared to strongly correlate with power per kg and this seemed to indicate that to run faster, athletes must also correctly manage their power.


Assuntos
Corrida , Atletas , Análise por Conglomerados , Marcha , Humanos , Consumo de Oxigênio
9.
Sensors (Basel) ; 20(21)2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33182357

RESUMO

BACKGROUND: The running segment of a triathlon produces 70% of the lower limb injuries. Previous research has shown a clear association between kinematic patterns and specific injuries during running. METHODS: After completing a seven-month gait retraining program, a questionnaire was used to assess 19 triathletes for the incidence of injuries. They were also biomechanically analyzed at the beginning and end of the program while running at a speed of 90% of their maximum aerobic speed (MAS) using surface sensor dynamic electromyography and kinematic analysis. We used classification tree (random forest) techniques from the field of artificial intelligence to identify linear and non-linear relationships between different biomechanical patterns and injuries to identify which styles best prevent injuries. RESULTS: Fewer injuries occurred after completing the program, with athletes showing less pelvic fall and greater activation in gluteus medius during the first phase of the float phase, with increased trunk extension, knee flexion, and decreased ankle dorsiflexion during the initial contact with the ground. CONCLUSIONS: The triathletes who had suffered the most injuries ran with increased pelvic drop and less activation in gluteus medius during the first phase of the float phase. Contralateral pelvic drop seems to be an important variable in the incidence of injuries in young triathletes.


Assuntos
Traumatismos em Atletas/prevenção & controle , Marcha , Aprendizado de Máquina , Corrida/lesões , Adolescente , Atletas , Fenômenos Biomecânicos , Eletromiografia , Humanos
10.
Molecules ; 25(21)2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33139590

RESUMO

Inulin is a polysaccharide of fructose widely used in the food and pharmaceutical industry due to its physicochemical properties and technological applications. Inulin from jicama (Smallanthus sonchifolius) and cabuya (Agave americana) was obtained. The steps for inulin obtention were: raw material preparation, extraction and purification. The extraction conditions were determined using a random design with three levels of stirring speed (0, 130 and 300 rpm), and a 32 factorial experimental design with three levels of temperature (40, 60 and 80 °C) and solid:liquid ratio (1:2, 1:3 and 1:5 S:L). The results showed that the best extractions conditions for jicama were 130 rpm, 75 °C, 1:5 S:L and 25 min; while for cabuya were 80 °C, 300 rpm, 1:5 S-L and 100 min. The weight average molecular weight of inulin from jicama and cabuya were 5799.9 and 4659.75 g/mol, respectively. The identity of the obtained inulin from jicama and cabuya were confirmed by infrared (IR) and Raman spectroscopy. In addition, scanning electron microscopy, differential scanning calorimetry and thermogravimetry analyses were performed to characterize both inulins.


Assuntos
Agave/química , Asteraceae/química , Frutanos/química , Frutanos/isolamento & purificação
11.
J Cell Sci ; 130(23): 4013-4027, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29061881

RESUMO

Cadherin-based intercellular adhesions are essential players in epithelial homeostasis, but their dynamic regulation during tissue morphogenesis and remodeling remain largely undefined. Here, we characterize an unexpected role for the membrane-anchored metalloproteinase MT2-MMP in regulating epithelial cell quiescence. Following co-immunoprecipitation and mass spectrometry, the MT2-MMP cytosolic tail was found to interact with the zonula occludens protein-1 (ZO-1) at the apical junctions of polarized epithelial cells. Functionally, MT2-MMP localizes in the apical domain of epithelial cells where it cleaves E-cadherin and promotes epithelial cell accumulation, a phenotype observed in 2D polarized cells as well as 3D cysts. MT2-MMP-mediated cleavage subsequently disrupts apical E-cadherin-mediated cell quiescence resulting in relaxed apical cortical tension favoring cell extrusion and re-sorting of Src kinase activity to junctional complexes, thereby promoting proliferation. Physiologically, MT2-MMP loss of function alters E-cadherin distribution, leading to impaired 3D organoid formation by mouse colonic epithelial cells ex vivo and reduction of cell proliferation within intestinal crypts in vivo Taken together, these studies identify an MT2-MMP-E-cadherin axis that functions as a novel regulator of epithelial cell homeostasis in vivo.


Assuntos
Caderinas/metabolismo , Homeostase/fisiologia , Mucosa Intestinal/metabolismo , Metaloproteinase 15 da Matriz/metabolismo , Junções Aderentes/metabolismo , Caderinas/genética , Movimento Celular/fisiologia , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Humanos , Junções Intercelulares/metabolismo , Junções Íntimas/metabolismo
12.
J Strength Cond Res ; 33(5): 1347-1353, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29019867

RESUMO

Williams, CC, Gdovin, JR, Wilson, SJ, Cazas-Moreno, VL, Eason, JD, Hoke, EL, Allen, CR, Wade, C, and Garner, JC. The effects of various weighted implements on baseball swing kinematics in collegiate baseball players. J Strength Cond Res 33(5): 1347-1353, 2019-The purpose of this study was to investigate the effects of different warm-up (WU) devices on bat swing parameters including maximal resultant velocity (MRV), resultant velocity at ball contact (RVBC), time difference between MRV and RVBC, bat angle at MRV, bat angle at RVBC, and perceptual differences of each WU implement used by National Collegiate Athletic Association Division-I baseball players. Fifteen varsity baseball players completed 1 experimental session during fall training. Retroreflective markers were placed on the bat and tee to measure basic bat kinematics during the swing. Participants completed a general calisthenics WU before being counter-balanced into 1 of 4 WU conditions: standard bat (SB) (33 in/30 oz), fungo (10.6 oz), weighted gloves with SB (weighted gloves) (55.6 oz) and donut with SB (donut) (55.6 oz). Each participant was asked to perform their normal on-deck routine over a 2-minute period, finishing with 5 practice swings with the designated condition. After completion of the WU, a 1-minute rest period (simulating normal game conditions) was given to allow each participant to get set to perform 5 maximal swings with a SB. Five, 1 × 4 (group × condition) repeated measures analysis of variance examined the aforementioned variables. There were no significant differences in MRV, RVBC, time difference between MRV and RVBC, and bat angle at MRV and RVBC between all WU conditions. If presented with the current options, athletes should choose the WU implement with which they are most comfortable using before an at-bat situation.


Assuntos
Beisebol/fisiologia , Equipamentos Esportivos/normas , Universidades , Exercício de Aquecimento/fisiologia , Adolescente , Atletas , Fenômenos Biomecânicos , Humanos , Masculino , Descanso/fisiologia , Adulto Jovem
13.
Ecol Appl ; 28(2): 373-384, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29171902

RESUMO

Mixed tree plantings and natural regeneration are the main restoration approaches for recovering tropical forests worldwide. Despite substantial differences in implementation costs between these methods, little is known regarding how they differ in terms of ecological outcomes, which is key information for guiding decision making and cost-effective restoration planning. Here, we compared the early ecological outcomes of natural regeneration and tree plantations for restoring the Brazilian Atlantic Forest in agricultural landscapes. We assessed and compared vegetation structure and composition in young (7-20 yr old) mixed tree plantings (PL), second-growth tropical forests established on former pastures (SGp), on former Eucalyptus spp. plantations (SGe), and in old-growth reference forests (Ref). We sampled trees with diameter at breast height (DBH) 1-5 cm (saplings) and trees at DBH > 5 cm (trees) in a total of 32 20 × 45 m plots established in these landscapes. Overall, the ecological outcomes of natural regeneration and restoration plantations were markedly different. SGe forests showed higher abundance of large (DBH > 20 cm) nonnative species, of which 98% were resprouting Eucalyptus trees, than SGp and PL, and higher total aboveground biomass; however, aboveground biomass of native species was higher in PL than in SGe. PL forests had lower abundance of native saplings and lianas than both naturally established second-growth forests, and lower proportion of animal dispersed saplings than SGe, probably due to higher isolation from native forest remnants. Rarefied species richness of trees was lower in SGp, intermediate in SGe and Ref and higher in PL, whereas rarefied species richness of saplings was higher in SG than in Ref. Species composition differed considerably among regeneration types. Although these forests are inevitably bound to specific landscape contexts and may present varying outcomes as they develop through longer time frames, the ecological particularities of forests established through different restoration approaches indicate that naturally established forests may not show similar outcomes to mixed tree plantings. The results of this study underscore the importance that restoration decisions need to be based on more robust expectations of outcomes that allow for a better analysis of the cost-effectiveness of different restoration approaches before scaling-up forest restoration in the tropics.


Assuntos
Recuperação e Remediação Ambiental , Florestas , Agricultura , Biodiversidade , Brasil , Clima Tropical
15.
J Strength Cond Res ; 32(1): 237-243, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28777246

RESUMO

Allen, CR, Fu, Y-C, Cazas-Moreno, V, Valliant, MW, Gdovin, JR, Williams, CC, and Garner, JC. Effects of jaw clenching and jaw alignment mouthpiece use on force production during vertical jump and isometric clean pull. J Strength Cond Res 32(1): 237-243, 2018-This study examined the effects of jaw clenching, a self-adapted, jaw-repositioning mouthpiece on force production during maximum countermovement vertical jump and maximum isometric midthigh clean pull assessments in an attempt to determine any ergogenic effect attributable to clenching, jaw-repositioning mouthpiece use, or the combination of both. Thirty-six male subjects performed vertical jump and isometric clean pull assessments from a force platform under various mouthpiece and clench conditions. A 3 × 2 (mouthpiece × clench) repeated-measures analysis of variance was conducted to analyze each of the following force production variables for both assessments: peak force, normalized peak force, and rate of force development. In addition, jump height was analyzed for the vertical jump. Results revealed improvements in peak force (F1,35 = 15.84, p ≤ 0.001, (Equation is included in full-text article.)= 0.31), normalized peak force (F1,35 = 16.28, p ≤ 0.001, (Equation is included in full-text article.)= 0.32), and rate of force development (F1,35 = 12.89, p = 0.001, (Equation is included in full-text article.)= 0.27) during the isometric clean pull assessment when participants maximally clenched their jaw, regardless of mouthpiece condition. There were no statistically significant differences in jump height, peak force, normalized peak force, or rate of force development during the vertical jump for any treatment condition. This study supports previous research demonstrating that the implementation of remote voluntary contractions such as jaw clenching can lead to concurrent activation potentiation and a resulting ergogenic effect during activities involving and requiring high-force production.


Assuntos
Contração Isométrica/fisiologia , Arcada Osseodentária/fisiologia , Protetores Bucais , Força Muscular/fisiologia , Coxa da Perna/fisiologia , Adolescente , Adulto , Humanos , Masculino , Músculo Esquelético/fisiologia , Adulto Jovem
16.
Radiology ; 285(1): 147-156, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28582632

RESUMO

Purpose To correlate multiparametric magnetic resonance (MR) imaging and quantitative digital histopathologic analysis (DHA) of the prostate. Materials and Methods This retrospective study was approved by the local institutional review board and was HIPAA compliant. Forty patients (median age, 60 years; age range, 44-71 years) who underwent prostate MR imaging consisting of T2-weighted and diffusion-weighted (DW) MR imaging along with subsequent robot-assisted radical prostatectomy gave informed consent to be included. Whole-mount tissue specimens were obtained with a patient-specific mold, and DHA was performed to assess the lumen, epithelium, stroma, and epithelial nucleus. These DHA images were registered with MR images and were correlated on a per-voxel basis. The relationship between MR imaging and DHA was assessed by using a linear mixed-effects model and the Pearson correlation coefficient. Results T2-weighted MR imaging, apparent diffusion coefficient (ADC) of DW imaging, and high-b-value DW imaging were significantly related to specific DHA parameters (P < .01). For instance, lumen density (ie, the percentage area of tissue components) was associated with T2-weighted MR imaging (slope = 0.36 ± 0.05 [standard error], γ = 0.35), ADC (slope = 0.47 ± 0.05, γ = 0.50), and high-b-value DW imaging (slope = -0.44 ± 0.05, γ = -0.44). Differences between regions harboring benign tissue and those harboring malignant tissue were observed at MR imaging and DHA (P < .01). Gleason score was significantly associated with MR imaging and DHA parameters (P < .05). For example, it was positively related to high-b-value DW imaging (slope = 0.21 ± 0.16, γ = 0.18) and negatively related to lumen density (slope = -0.19 ± 0.18, γ = -0.35). Conclusion Overall, significant associations were observed between MR imaging and DHA, regardless of prostate anatomy. © RSNA, 2017 Online supplemental material is available for this article.


Assuntos
Histocitoquímica/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Próstata , Neoplasias da Próstata , Adulto , Idoso , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Estudos Retrospectivos
17.
J Urol ; 197(2): 327-334, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27582434

RESUMO

PURPOSE: Multiparametric magnetic resonance imaging and fusion biopsy detect more high risk prostate cancer and less low risk prostate cancer than systematic biopsy. However, there remains a small subset of patients in whom systematic biopsy captures higher grade disease than fusion biopsy. We sought to identify potential mechanisms of the failure of fusion biopsy in the detection of clinically significant prostate cancer. MATERIALS AND METHODS: We reviewed a prospectively maintained database of patients who underwent multiparametric magnetic resonance imaging followed by fusion biopsy and systematic biopsy from 2007 to 2014. In patients in whom disease was upgraded to clinically significant disease (Gleason 7 or greater) by systematic biopsy over fusion biopsy, independent re-review of magnetic resonance imaging, archived biopsy imaging and whole mount pathology as well as needle coordinate mapping were performed. Multivariate logistic regression analysis was done to determine predictors of upgrading by systematic biopsy. RESULTS: Disease was upgraded based on systematic biopsy over fusion biopsy in 135 of 1,003 patients (13.5%), of whom only 62 (6.2%) were upgraded to intermediate (Gleason 7) and high risk (Gleason 8 or greater) prostate cancer (51 or 5.1% and 11 or 1.1%, respectively). On multivariate analysis lower prostate specific antigen (p <0.001), higher magnetic resonance imaging prostate volume (p <0.001) and a lower number of target cores (p = 0.001) were predictors of upgrading by systematic biopsy. Main mechanisms of under grading by fusion biopsy included multiparametric magnetic resonance imaging reader oversight, presence of magnetic resonance imaging invisible cancer, fusion biopsy technique error and intralesion Gleason heterogeneity. CONCLUSIONS: Magnetic resonance imaging and fusion biopsy rarely missed clinically significant prostate cancer as only 62 of 1,003 cases (6.2%) were upgraded to clinically significant disease by systematic biopsy. Imaging and biopsy techniques are continually refined. Further studies will help clarify mechanisms of fusion biopsy failure and the patient populations that benefit from systematic biopsy in addition to fusion biopsy.


Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Imageamento por Ressonância Magnética/métodos , Próstata/patologia , Neoplasias da Próstata/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neoplasias da Próstata/diagnóstico por imagem , Estudos Retrospectivos
18.
J Cell Sci ; 127(Pt 17): 3768-81, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24994937

RESUMO

Cell-cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier strength. We identify the Ig superfamily member EMMPRIN (also known as basigin) as a coordinator of forces at endothelial junctions. EMMPRIN localization at junctions correlates with endothelial junction strength in different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased junction permeability. Lack of EMMPRIN alters the localization and function of VE-cadherin (also known as cadherin-5) by decreasing both actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin (also known as junction plakoglobin) and Nm23 (also known as NME1), a nucleoside diphosphate kinase, thereby locally providing ATP to fuel the actomyosin machinery. These results provide a novel mechanism for the regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly.


Assuntos
Actomiosina/metabolismo , Trifosfato de Adenosina/biossíntese , Basigina/metabolismo , Células Endoteliais/citologia , Nucleosídeo NM23 Difosfato Quinases/metabolismo , gama Catenina/metabolismo , Animais , Adesão Celular/fisiologia , Membrana Celular/metabolismo , Células Cultivadas , Proteínas do Citoesqueleto/biossíntese , Endotélio Vascular/metabolismo , Junções Intercelulares/metabolismo , Camundongos
19.
Opt Express ; 22(13): 15346-51, 2014 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-24977794

RESUMO

We propose and experimentally demonstrate a scalable and reconfigurable optical scheme to generate high order UWB pulses. Firstly, various ultra wideband doublets are created through a process of phase-to-intensity conversion by means of a phase modulation and a dispersive media. In a second stage, doublets are combined in an optical processing unit that allows the reconfiguration of UWB high order pulses. Experimental results both in time and frequency domains are presented showing good performance related to the fractional bandwidth and spectral efficiency parameters.

20.
Anat Rec (Hoboken) ; 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39096041

RESUMO

Dynamic camouflage is the capacity to rapidly change skin color and pattern, often for the purpose of background-matching camouflage. Summer flounder (Paralichthys dentatus) are demersal fish with an exceptional capacity for dynamic camouflage, but with eyes that face away from the substrate, it is unknown if this behavior is mediated by vision. Past studies have shown that summer flounder skin can match the pattern (i.e., spatial detail) of substrate with a high degree of precision, and for that to be achieved using sight, one testable assumption is that the resolution of vision must match the degree of detail produced in color-change performance. To test this, approaches in morphology and behavior were used to estimate visual acuity, which is the capacity of the visual system to resolve static spatial detail. Using image processing techniques, we then compared the degree of spatial detail from a relevant substrate with what may be detectable by summer flounder spatial vision. The morphological and behavioral estimates of visual acuity were calculated as 3.62 cycles per degree (CPD) ± 0.8 (s.d.) and 4.06 CPD ± 0.4 (s.d.), respectively. These estimates fall within a range of acuities known among other flatfishes and appear adequate for detecting the spatial information needed for background-matching camouflage, though only at close distances. These data provide new knowledge about summer flounder visual acuity and suggest the capacity of flounder vision to support dynamic camouflage of the skin.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA