Segurança do trabalho em unidades de beneficiamento de frutas e hortaliças.

bitstream/CNPDIA-2010/12628/1/CT102-2009.pd

Necessary Optimality Conditions for Higher-Order Infinite Horizon Variational Problems on Time Scales

We obtain Euler-Lagrange and transversality optimality conditions for higher-order infinite horizon variational problems on a time scale. The new necessary optimality conditions improve the classical results both in the continuous and discrete settings: our results seem new and interesting even in the particular cases when the time scale is the set of real numbers or the set of integers.Comment: This is a preprint of a paper whose final and definite form will appear in Journal of Optimization Theory and Applications (JOTA). Paper submitted 17-Nov-2011; revised 24-March-2012 and 10-April-2012; accepted for publication 15-April-201

Cosmic String Network Evolution in arbitrary Friedmann-Lemaitre models

We use the velocity-dependent one-scale model by Martins & Shellard to investigate the evolution of a GUT long cosmic string network in arbitrary Friedmann-Lemaitre models. Four representative models are used to show that in general there is no scaling solution. The implications for structure formation are briefly discussed.Comment: 8 pages, 4 postscript figures included, submitted to Phys. Rev.

Respiratory muscles's thermographic analysis in asthmatic youth with and without bronchospasm induced by eucapnic voluntary hyperpnea

Objective To compare the thermographic pattern of regions of interest (ROI) of respiratory muscles in young asthmatics with and without bronchospasm induced by eucapnic voluntary hyperpnea (EVH). Materials and Methods Cross-sectional study carried out with 55 young (55% male and 45% females) aged 12.5 ± 3.3 years, divided in nine nonasthmatics, 22 asthmatics without exercise-induced bronchospasm compatible response (EIB-cr) and 24 asthmatics with EIB-cr. The diagnosis of EIB was given to subjects with a fall in forced expiratory volume in the first second (FEV1) ≥ 10% compared to baseline. Thermographic recordings of respiratory muscles were delimited in ROI of the sternocleidomastoid (SCM), pectoral, and rectus abdominis intention area. Thermal captures and FEV1 were taken before and 5, 10, 15 and 30 min after EVH. Results Twenty-four (52.1%) of asthmatics had EIB-cr. There was a decrease in temperature at 10 min after EVH test in the SCM, pectoral and rectus abdominis ROIs in all groups (both with p < 0.05). There was a decrease in temperature (% basal) in asthmatic with EIB-cr compared to nonasthmatics in the rectus abdominis area (p < 0.05). Conclusion There was a decrease in temperature in the ROIs of different muscle groups, especially in asthmatics. The greater drop in FEV1 observed in individuals with EIB-cr was initially associated with a decrease in skin temperature, with a difference between the nonasthmatics in the abdominal muscle area. It is likely that this decrease in temperature occurred due to a temporary displacement of blood flow to the most used muscle groups, with a decrease in the region of the skin evaluated in the thermography

Cut-off points of the 1-minute sit-to-stand test to detect functional impairment and mortality risk in people with COPD

Introduction: Functional status is a key outcome in people with chronic obstructive pulmonary disease (COPD) and can be defined as an individual’s ability to perform normal daily activities required to meet basic needs, fulfill usual roles, and maintain health and well-being. The 1-minute sit-to-stand test (1-min STS) is a wellestablished measure to assess functional status in people with COPD that can be used in different settings (e.g., office, clinic, hospital, home) with limited resources (i.e., a chair and a stopwatch). This test is a strong predictor of exacerbations, hospitalizations and mortality in people with COPD. Yet, cut-off points to determine functional impairment with the 1-min STS in people with COPD are lacking for use in clinical practice. Recently, our group established a cut-off (19.5 repetitions) for increased mortality risk, however, it still lacks external validation. Objectives: To explore the predictive ability of the 1-min STS to detect functional impairment and the validity of the previously established cut-off for increased risk of mortality in people with COPD. Methods: A cross-sectional study was conducted with people with COPD. Age, sex, body mass index (BMI), lung function, the 1-min STS and the five-repetitions sit-to-stand tests were collected. We used two cut-offs for the five-repetitions sit-to-stand test known to be associated with low functional performance (12.1 seconds) and increased risk of mortality (15.98 seconds) in people with COPD. Receiver operating characteristics analysis (ROC) was performed and the area under the curve (AUC), sensitivity, specificity, and accuracy were calculated. The optimal cut-off points were identified by the highest Younden index. Results: In total, 302 people with COPD (67.5 ± 10.4 years; 79.1% male; BMI 26.7 ± 4.6 kg/m²; FEV1 55.2 ± 20.4%predicted) participated. Cut-off points in the 1-min STS of 23.5 repetitions for low functional performance (AUC = 0.92; 95%CI 0.89-0.95; 96.4% sensitivity; 80.9% specificity; accuracy = 0.84) and 18.5 repetitions for increased risk of mortality (AUC = 0.97; 95%CI 0.94-0.987; 95.5% sensitivity; 88.6% specificity; accuracy = 0.89) were found in people with COPD. Conclusions: The 1-min STS showed an outstanding discriminative ability and excellent accuracy in determining low functional performance and increased risk of mortality in people with COPD. A cut-off of 23.5 repetitions can be used to identify people with functional impairment. The cut-off point found for increased risk of mortality is similar to the previously published using the 6-minute walk test as an anchor, reinforcing the validity of this cut-off. These cut-offs support healthcare professionals in tailoring an appropriate management plan for this treatable trait and might possibly contribute to the implementation of timely preventive or palliative strategies.publishe

AVERAGE TOTAL HEMISPHERIC EMISSIVITY MEASUREMENT IN THE LWIR SPECTRUM FOR ADHESIVE TAPES USED IN THE THERMOGRAPHY TAPE TEST

Thermographers often use comparative methods to estimate surfaceemissivity. Among the most used is the tape method. In this method a knownemissivity tape in the LWIR (Long Wavelength Infrared) spectrum is placedon the surface to be inspected. After thermal equilibrium, the temperature ofthe tape and the surface under inspection must be the same. In this case, thetemperature observed on the tape is the reference temperature. The emissivityof the surface must then be changed until the reference temperature isreached. It is common practice to admit the value of the emissivity of theadhesive tape as 0.95, there are few studies that present these data withmetrological rigor, which leads to doubts about the emissivity of thecommercial tapes. In this work, experiments were performed on Tekbond,Double A, 3M 101, Rapix, Altape, adhesive tapes for temperatures of 50, 55,60, 65 and 70ºC. An experimental apparatus was developed through which itwas possible to estimate surface reflection, transmission and atmosphericemission for one and two layers of tapes, in order to make emissivitymeasurements possible. Through the data it was possible to statisticallyestimate the LWIR average total hemispheric emissivity as well as theacceptance range to 95% certainty, being therefore equal to ε=0.94±0.03. Itis possible to arm, therefore, that the value of 0.95, usually used as emissivityof the adhesive tape, is extremely reasonable because it is 0.01 of the averagevalue of the Gaussian distribution calculated by this work

Targeting cancer resistance via multifunctional gold nanoparticles

POCI-01-0145-FEDER-007728 SFRH/BD/120030/2016 PD/BD/105734/2014 Pest-OE/UID/DTP/04138/2013Resistance to chemotherapy is a major problem facing current cancer therapy, which is continuously aiming at the development of new compounds that are capable of tackling tumors that developed resistance toward common chemotherapeutic agents, such as doxorubicin (DOX). Alongside the development of new generations of compounds, nanotechnology-based delivery strategies can significantly improve the in vivo drug stability and target specificity for overcoming drug resistance. In this study, multifunctional gold nanoparticles (AuNP) have been used as a nanoplatform for the targeted delivery of an original anticancer agent, a Zn(II) coordination compound [Zn(DION)2]Cl2 (ZnD), toward better efficacy against DOX-resistant colorectal carcinoma cells (HCT116 DR). Selective delivery of the ZnD nanosystem to cancer cells was achieved by active targeting via cetuximab, NanoZnD, which significantly inhibited cell proliferation and triggered the death of resistant tumor cells, thus improving efficacy. In vivo studies in a colorectal DOX-resistant model corroborated the capability of NanoZnD for the selective targeting of cancer cells, leading to a reduction of tumor growth without systemic toxicity. This approach highlights the potential of gold nanoformulations for the targeting of drug-resistant cancer cells.publishersversionpublishe