The present paper describes fundamentals, advantages and limitations of the Box-Behnken design (BBD) for the optimization of analytical methods. It establishes also a comparison between this design ...and composite central, three-level full factorial and Doehlert designs. A detailed study on factors and responses involved during the optimization of analytical systems is also presented. Functions developed for calculation of multiple responses are discussed, including the desirability function
, which was proposed by Derringer and Suich in 1980. Concept and evaluation of robustness of analytical methods are also discussed. Finally, descriptions of applications of this technique for optimization of analytical methods are presented.
Grape bagasse generated in the wine production process was characterized through X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic ...resonance and thermogravimetric analysis. The efficiency of this natural material for Cd(II) and Pb(II) adsorption was evaluated using a batch adsorption technique. Factors affecting metal adsorption such as pH and contact time were investigated. Maximum adsorption was found to occur at pH 7.0 and 3.0 for Cd(II) and Pb(II), respectively, and a contact time of 5
min was required to reach equilibrium for both metals. With these conditions, adsorption studies were performed using a single solution. In addition, to calculate the adsorption capacities for each metal, the Langmüir isotherm model was used. The adsorption capacities were found to be 0.479 and 0.204
mmol
g
−1 for Cd(II) and Pb(II), respectively. The results showed that grape bagasse could be employed as a low-cost alternative adsorbent for effluent treatment.
Objectives
To compare the values obtained from maximum respiratory pressures (MRP) between sarcopenic and non-sarcopenic elderly; to verify the association of maximum respiratory pressures with ...sarcopenia and its indicators; and to establish cut-off points for MRP as a discriminator of sarcopenia.
Design
Cross-sectional study.
Location
Macapá, Brazil.
Participants
Community-dwelling elderly ≥ 60 years old, both sexes.
Measures
Evaluation of respiratory muscle strength (maximal inspiratory pressure - MIP and maximal expiratory pressure - MEP) and sarcopenia, according to the European Working Group on Sarcopenia in Older People (EWGSOP), in which the diagnosis of this condition considered the reduction of muscle mass (muscle mass index - MMI) associated with muscle strength reduction (hand grip strength - HGS) and / or impairment in physical performance (gait speed - GS).
Results
The sample consisted of 383 elderly individuals, with a mean age of 70.02 ± 7.3 years and a prevalence of sarcopenia of 12.53% (n = 48). Sarcopenic individuals presented significantly lower (obtained, obtained versus predicted) mean values for the maximal respiratory pressures compared to the non-sarcopenic elderly, and these were inversely associated with sarcopenia (an increase by 1 cmH2O in MIP and MEP reduced by 5% and 3%, respectively, the probability of sarcopenia). In relation to the association with the sarcopenia indicators, the increase by 1 cmH2O in MIP and MEP decreased, respectively, the probability of decreasing muscle strength (3% and 2%), GS (3% and 4%) and MMI (3 % - MIP). Cut-off points ≤60 cmH2O and ≤50 cmH2O for MEP and ≤55 cmH2O and ≤45 cmH2O for MEP, respectively for elderly men and women, served as a discriminant criterion for the presence of sarcopenia (area under the ROC curve superior to 0.70).
Conclusions
Elderly patients with sarcopenia had lower MIP and MEP values when compared to non-sarcopenic individuals, and respiratory muscle strength was inversely associated with the diagnosis of sarcopenia and its indicators (HGS, gait speed and MMI). Furthermore, cut-off points for MIP and MEP can be used in clinical practice as discriminators of sarcopenia in community-dwelling elderly.
Productivity is a key-factor for companies manufacturing parts and sets to the automotive industry. Automation plays an important role in this matter, allowing development of entire manufacturing ...cells without the direct need of workers. Even in countries where the labour cost is relatively low, it becomes necessary to improve the level of automation applied to manufacturing cells and reduce the dependence of the human labour unpredictability, also increasing the quality and reducing the costs. This case study was developed based on an industrial request in order to improve a semi-automatic cell devoted to seat suspension mat manufacturing. The original cell allows several automatic operations but it needs two workers for two specific operations not considered in the initial design. Thus, new concepts of wire feeding and manipulation were developed in order to allow a better material flow throughout the cell. The new cell was designed and built with success, allowing to obtain a full-automated system, which leads to a better productivity and reliability of the manufacturing process.
The biological maturation (BM) analyzed by peak height velocity (PHV) and bone age (BA), and lean body mass has been associated with the strength and muscle power of young athletes. However, the ...ability of BM (PHV and BA) and LM markers to predict muscle strength and power in young athletes remains uncertain. The Aim was determine the predicting power of BM markers (PHV and BA) and LM in relation to muscle power of upper and lower limbs and muscle strength of upper limbs in adolescent athletes at puberty. Ninety-two adolescent athletes (both sexes; age 12.4 ± 1.02 years) were assessed for body composition by dual-energy X-ray absorptiometry (DXA). Power of upper limbs (ULP), force handgrip (HG), vertical jump (VJ) and countermovement jump (CMJ) were recorded. BM was predicted by mathematical models to estimate PHV and BA. Multilayer artificial neural network analyses (MLP's) were used to determine the power of prediction of LM, PHV and BA on muscle power and strength of upper- and lower-limbs of the athletes. LM, BA and PHV were associated with HG (r>0.74, p0.60, p0.55, p0.53, p0.60, p<0.05) with BA and with PHV (r<0.83, p 72% of probability to predict the muscle power of upper- and lower-limbs, and the strength of the upper limbs; whereas PHV provides > 43% and bone age >64% in both female and male adolescent athletes. We identified that, like PHV and BA, LM is a strong predictor of low cost of both upper limbs muscle strength and upper and lower limbs power in adolescent athletes.
A synergistic effect resulting from the interaction of small (2.4–3.1 nm) naked Pt nanoparticles (NPs) imprinted on N‐doped carbon supports is evidenced by structural, electronic and electrochemical ...characterization. The size and distribution of the sputtered Pt NPs are found to be related to the nature of the support because Pt NPs are preferentially located at Ngraphitic sites. In addition, Rutherford backscattering shows that a deeper penetration of the Pt NPs is obtained in the N‐doped carbon support with larger pore diameters. The ligand effect of the N‐doped carbon supports is found to occur by electron donation from Npyrrolic and Ngraphitic sites to the Pt NPs and the electron acceptor behavior of the C=Npyridinic sites. The carbon matrix acquires a basic characteristic (electron‐richer, metallic behavior) capable of interacting with metallic NPs akin to a bimetallic‐like system. The imprinted Pt NPs are active catalysts for oxidation, although displaying poor catalytic activity for reduction reactions. The catalyst N‐doped carbon supports play an important role in the overall catalytic process, rather than only acting as a simple active phase carrier.
Naked nanoparticles: A synergic effect between small and well‐distributed Pt nanoparticles (NPs) and N‐doped carbon‐supported naked Pt nanoparticles accounts for the electronic structure of resulting materials. Naked Pt nanoparticles obtained by sputtering deposition onto N‐doped carbons display high electro(catalytic) activity for oxidation reactions and poor activity for hydrogenation reactions. The simple donor–acceptor metal–ligand model can be used for the design of supported metal NPs on carbon supports with controlled electronic properties.
Roads are human infrastructure that heavily affect wildlife, often with marked impacts on carnivores, including brown bears Ursus arctos. Here, we assessed the potential impact of road networks on ...the distribution of brown bears in the small, isolated and endangered Cantabrian population of north‐western Spain. To ascertain whether local road networks affect brown bear spatial distribution, we first assessed potential influences on the distance of bear locations to roads using candidate models which included topographic variables, landcover types, bear age and reproductive status, traffic volume and road visibility. Then, we built two sets of habitat suitability models, both with and without roads, to discern the possible loss of habitat suitability caused by roads. The mean distance of bear locations to the nearest road was 968 ± 804 m and the closest road was a low traffic road in 72.5% of cases. Candidate models showed little influence of our variables on bear distance to the nearest road, with the exception of elevation. Habitat suitability models revealed that road networks in our study area seem to have almost no effect on brown bear habitat suitability, except for females with yearlings during the denning season. However, this result may also be a consequence of the fact that only a small proportion (16.5%) of the cells classified as suitable bear habitats were crossed by roads, that is, most of the roads are primarily located in unsuitable bear habitats in the Cantabrian Mountains. Compared to previous studies conducted in other populations, mainly North American ones, our findings might suggest a different response of Eurasian brown bears to roads due to a longer bear‐human coexistence in Europe versus North America. However, the indirect approach used in our study does not exclude other detrimental effects, for example, road mortality, increased stress and movement pattern disruption, only detectable by more direct approaches such as telemetry.
The distance of Cantabrian brown bear locations from roads does not seem to be significantly affected by the characteristics of the environment and roads, nor by the type of bear or season. Similarly, habitat suitability is not overly affected by these variables. These findings contrast with those of other populations inhabiting areas with more recent anthropization, such as the North American ones.
Abstract Streptococcus pneumoniae is one of the primary pathogens that are associated with acute respiratory infections (ARI) that cause high rates of morbidity and mortality among children under ...five years of age in developed and developing countries. This study aimed to determine the prevalence of nasopharyngeal colonization, the antimicrobial resistance profile, and the capacity for biofilm formation by S. pneumoniae isolated from children aged 0-6 years with ARI throughout the Porto Velho-RO. A total of 660 swabs were collected from children with ARI. Molecular and biochemical tests were performed to characterize the isolates. The disk-difusion method and the E-test were used for antimicrobial sensitivity testing (TSA). Biofilm formation capacity was assessed using microtiter plate assays, and serotype detection was acheived using polymerase chain reaction (PCR) analyses. The colonization rate for S. pneumoniae was 8.9% (59/660) and exhibited a high prevalence in children under 23 months of age 64.4% (38/59). The observed serotypes were 9V and 19F with frequencies of 1.7% (1/59) and 13.6% (8/59), respectively. The antimicrobial susceptibility test revealed 100% (59/59) sensitivity to vancomycin. In contrast, trimethoprim and oxacillin exhibited high resistance rates of 76.3% (45/59) and 52.5% (31/59), respectively. Of the biofilm-forming isolates, 54.8% (23/42) possessed resistance to some antimicrobials. In this study, S. pneumoniae showed high rates of antimicrobial resistance and the ability to form biofilms, as these are factors that favor bacterial persistence and can cause serious damage to the host.
Resumo Streptococcus pneumoniae é um dos principais patógenos associados a infecções respiratórias agudas (IRAs) que causam altas taxas de morbidade e mortalidade entre crianças menores de cinco anos de idade em países desenvolvidos e em desenvolvimento. Este estudo teve como objetivo determinar a prevalência de colonização da nasofaringe, o perfil de resistência antimicrobiana e a capacidade de formação de biofilme dos S. pneumoniae isolados de crianças de 0 a 6 anos com IRA na cidade de Porto Velho-Rondônia. Um total de 660 swabs foi coletado de crianças com IRA. Testes moleculares e bioquímicos foram realizados para identificar os isolados bacterianos. O método de disco-difusão e o E-test foram utilizados para o teste de sensibilidade antimicrobiana (TSA). A capacidade de formação de biofilme foi avaliada por meio de ensaios em placas de microtitulação e a detecção de sorotipos foi obtida por meio de análises de Reação em Cadeia da Polimerase (PCR). A taxa de colonização por S. pneumoniae foi de 8,9% (59/660) e apresentou alta prevalência em menores de 23 meses de idade 64,4% (38/59). Os sorotipos identificados foram 9V e 19F com frequências de 1,7% (1/59) e 13,6% (8/59) respectivamente. O teste de sensibilidade aos antimicrobianos revelou 100% (59/59) de sensibilidade à vancomicina. Em contraste, trimetoprima e oxacilina apresentaram altas taxas de resistência de 76,3% (45/59) e 52,5% (31/59) respectivamente. Dos isolados formadores de biofilme 54,8% (23/42) possuíam resistência a alguns dos antimicrobianos. Neste estudo, S. pneumoniae apresentou altas taxas de resistência antimicrobiana e capacidade de formar biofilmes, pois são fatores que favorecem a persistência bacteriana e podem causar sérios danos ao hospedeiro.
Objectives
To compare the obtained and expected values of pulmonary function variables between sarcopenic and non-sarcopenic elderly; verify the association between the pulmonary function and the ...indicators and diagnosis of sarcopenia; and establish cut-off points for pulmonary function variables to predict sarcopenia.
Design
Cross-sectional study.
Location
Macapá, Brazil.
Participants
community-dwelling elderly ≥ 60 years old (n=383), both sexes.
Measures
Were evaluated according to variables of pulmonary function (spirometry) and sarcopenia, according to the EWGSOP consensus. The association between pulmonary function and sarcopenia was performed using logistic regression and cut-off points established from the ROC Curve.
Results
The prevalence of sarcopenia was 12.53% (n = 48). Sarcopenic individuals had significantly lower mean values for FVC, FEV
1
, FEF
25–75%
and PEF than non-sarcopenic. After adjustment, spirometric variables were inversely associated with sarcopenia (the increase by one unit of liter in FVC, FEV
1
and FEF
25–75%
decreased the probability of sarcopenia by 59%, 67% and 39%, respectively), and the majority of these variables with the muscular strength indicator. Cut-off points, for elderly men and women, were discriminant criteria for the presence of sarcopenia: FVC (≤2.52 L and ≤1.82 L), FEV
1
(≤2.1 L and ≤1.39 L), PEF (≤3.45 L/s and ≤2.93 L/s) and FEF
5–75%
(≤1.97 L/s and ≤1.74 L/s).
Conclusions
There was loss of pulmonary function in sarcopenic elderly patients and an inverse association with the diagnosis of sarcopenia and its indicators. Cut-off points of pulmonary function variables can be used as a useful tool to discriminate sarcopenia.
Objectives
To compare the obtained and predicted peak expiratory flow (PEF) values between frail, pre-frail, and non-frail older adults; verify the association between PEF and FS; and establish ...cut-off points for PEF as determinants of frailty syndrome (FS).
Design
Cross-sectional study.
Location
Macapá, Amapá, Brazil.
Participants
Community-based study community-dwelling older people.
Methods
PEF was evaluated using a peak-flow meter and FS was evaluated using Fried’s frailty phenotype. The statistical analyses performed included a multinomial logistic regression model and Receiver Operating Characteristic (ROC) curves to establish cut-off points for discriminating FS.
Results
409 older adults with a mean age of 70.09±7.22 years were evaluated; of these, 58.7% were pre-frail, and 12.7% were frail. PEF was lower in frail than in pre-frail participants, and lower in pre-frail than in non-frail. Frail and pre-frail older adults obtained lower PEF values than predicted. PEF (% Predicted) was inversely associated with frailty and pre-frailty even after adjustment. Cut-off points were established to discriminate the presence of frailty in older men (PEF≤350L/min; AUC=0.669; sensitivity=76.92%; specificity=52%) and women (PEF≤220L/min; AUC=0.597; sensitivity=71.79%; specificity=46.98%).
Conclusions
Frail and pre-frail older adults presented significantly lower PEF than non-frail participants, and these values were lower than predicted. PEF was inversely associated with frailty and pre-frailty. PEF cut-off points can be used as a complementary method to indicate frailty in community-dwelling older adults.
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