Two different Al2O3 coatings manufactured by plasma spraying process were tested under dry sliding contact conditions at high temperatures in order to determine their tribological behavior. At higher ...temperature than 800 °C, wear rate and mechanisms for Al2O3 coatings have not yet been reported. The results obtained were compared with those from both: an electro-melted Al2O3 refractory used as reference and a pressed & sintered silico-aluminous refractory used as substrate, which were tested under the same conditions. The reference was chosen due to the high performance against wear that this material shows, and the substrate was chosen due to the high potential that this material with low properties against wear shows when it is coated. Crystallographic phases, micro-hardness, Young's modulus and fracture toughness were measured before and after the wear tests, obtaining as results that both Al2O3 coatings showed better wear performance than the pressed & sintered silico-aluminous refractory used as substrate, and even than the electro-melted Al2O3 refractory used as reference. Additionally, in the plasma sprayed coatings, as well as, in the electro-melted Al2O3 refractory, the wear mechanism was controlled by a transformation produced by the increasing in temperature from ductile deformation to brittle deformation, for finally returning to ductile deformation again. The high performance of plasma sprayed coatings was mainly due to the high values of toughness, as well as due to the increasing of the α-Al2O3 levels and therefore, the hardness during the wear tests because of the high temperature, allowing to these ceramic coatings to be a possible way to protect the conventional pressed & sintered silico-aluminous refractories to replace the expensive non-structural electro-melted ones currently exposed to abrasive wear in glass, cement and other primary industries.
•The wear resistance at 1000 °C of two different Al2O3 coatings was evaluated.•The quantity of α-Al2O3 increased at 1000 °C in both coatings evaluated.•Both Al2O3 coatings showed similar wear resistance at 1000 °C.•Both coatings showed better wear resistance at 1000 °C than the reference refractory.•Both coatings can protect at 1000 °C the refractory used as substrate.
Objective To determine the prevalence of hypertension and pre-hypertension on the basis of the 2004 National High Blood Pressure Education Program Working Group guidelines in an adolescent ...school-screening population. Study design Cross-sectional assessment of blood pressure (BP) in 6790 adolescents (11-17 years) in Houston schools was conducted from 2003 to 2005. Initial measurements included height, weight, and 4 oscillometric BP readings. Repeat measurements were obtained on 2 subsequent occasions in students with persistently elevated BP. Final prevalence was adjusted for loss to follow-up and logistic regression used to assess risk factors. Results BP distribution at initial screen was 81.1% normal, 9.5% pre-hypertension, and 9.4% hypertension (8.4% Stage 1; 1% Stage 2). Prevalence after 3 screenings was 81.1% normal, 15.7% pre-hypertension, and 3.2% hypertension (2.6% Stage 1; 0.6% Stage 2). Hypertension and pre-hypertension increased with increasing body mass index. Sex, race, and classification as either at-risk for overweight or overweight were independently associated with pre-hypertension. Only classification as overweight was associated with hypertension. Conclusions Application of new classification guidelines for adolescents with elevated BP reveals ∼20% are at risk for hypertension. Further research determining the significance of each BP category and refining definitions to account for BP variability is warranted.
AIM: Evaluate technologically relevant properties from bacteriocin‐producing strains to use as starter/adjunct cultures in cheese making. METHODS AND RESULTS: Eight isolates obtained from Pico cheese ...produced in Azores (Portugal) were found to produce bacteriocins against Listeria monocytogenes and three isolates against Clostridium perfringens. They were identified as Lactococcus lactis and Enterococcus faecalis and submitted to technological tests: growth at different conditions of temperature and salt, acid production, proteolysis, lipolysis, coexistence, enzymatic profile and autolytic capacity. Safety evaluation was performed by evaluating haemolytic, gelatinase and DNase activity, resistance to antibiotics and the presence of virulence genes. Some isolates presented good technological features such as high autolytic activity, acid and diacetyl production. Lactococcus lactis was negative for all virulence genes tested and inhibit the growth of all Lactic acid bacteria (LAB) isolates. Enterococci were positive for the presence of some virulence genes, but none of the isolates were classified as resistant to important antibiotics. CONCLUSIONS: The bacteriocin‐producing Lc. lactis present good potential for application in food as adjunct culture in cheese production. The study also reveals good technological features for some Enterococcus isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriocin‐producing strains presented important technological properties to be exploited as new adjunct culture for the dairy industry, influencing flavour development and improve safety.
Aquatic pollution is one of the greatest environmental problems, and therefore its control represents one of the major challenges in this century. In recent years, proteomics has emerged as a ...powerful tool for searching protein biomarkers in the field of pollution biomonitoring. For biomonitoring marine contamination, there is a consensus that bivalves are preferred organisms to assess organic and inorganic pollutants. Thus, the bivalve proteome was intensively studied, particularly the mussel. It is well documented that heavy metal pollution and organic chemicals altered the structural proteins causing degradation of tissues of molluscs. Also, it is well known that proteins involved in stress oxidative such as glutathione and enzymes as catalase, superoxide dismutase or peroxisomes are overexpressed in response to contaminants. Additionally, using bivalves, other groups of proteins proposed as pollution biomarkers are the metabolic proteins. Even though other marine species are used to monitor the pollution, the presence of proteomic tools in these studies is scarce. Concerning freshwater pollution field, a great variety of animal species (fish and crustaceans) are used as biomonitors in proteomics studies compared to plants that are scarcely analysed. In fish species, proteins involved in stress oxidative such as heat shock family or proteins from lipid and carbohydrate metabolism were proposed as candidate biomarkers. On the contrary, for crustaceans there is a lack of proteomic studies individually assessing the contaminants. Novel scenarios, including emerging contaminants and new threats, will require proteomic technology for a systematic search of protein biomarkers and a greater knowledge at molecular level of those cellular pathways induced by contamination.
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•Proteomics is a powerful tool in the quest for pollution biomarkers in biomonitors.•Molluscs protein biomarkers are well studied in marine pollution.•Structural, metabolic, stress oxidative proteins of marine bivalves as biomarkers.•Fish protein biomarkers are most used in freshwater pollution.•Emerging pollutants offers a new challenge for a proteomic approach.
This study reviews published scientific literature on the use of tangible technologies in childhood education, in order to (a) identify the what tangible technologies have been used, (b) recognize ...the educational purposes and uses these technologies of, and (c) present a synthesis of the available empirical evidence on its educational effectiveness. After systematically searching in WoS, 288 relevant articles were located and analyzed using the Science Mapping Analysis Software Tool from 1968 to 2018. Then, 29 relevant papers of the last five years were included in the review study. For each article, we analyze the purpose of the study, the type of tangible technology used, the research method applied, the sample characteristics and the main results observed. The articles reviewed suggest that the main tangible technology used in childhood education is the tablet and literacy (basic and emergent) is the area most studied with promising results.
Neoadjuvant chemotherapy (NAC) induces a pathologic complete response (pCR) in approximately 30% of patients with triple-negative breast cancers (TNBC). In patients lacking a pCR, NAC selects a ...subpopulation of chemotherapy-resistant tumor cells. To understand the molecular underpinnings driving treatment-resistant TNBCs, we performed comprehensive molecular analyses on the residual disease of 74 clinically defined TNBCs after NAC, including next-generation sequencing (NGS) on 20 matched pretreatment biopsies. Combined NGS and digital RNA expression analysis identified diverse molecular lesions and pathway activation in drug-resistant tumor cells. Ninety percent of the tumors contained a genetic alteration potentially treatable with a currently available targeted therapy. Thus, profiling residual TNBCs after NAC identifies targetable molecular lesions in the chemotherapy-resistant component of the tumor, which may mirror micrometastases destined to recur clinically. These data can guide biomarker-driven adjuvant studies targeting these micrometastases to improve the outcome of patients with TNBC who do not respond completely to NAC.
This study demonstrates the spectrum of genomic alterations present in residual TNBC after NAC. Because TNBCs that do not achieve a CR after NAC are likely to recur as metastatic disease at variable times after surgery, these alterations may guide the selection of targeted therapies immediately after mastectomy before these metastases become evident.
Because of growing urbanization and lack of time to prepare meals at home, eating out or getting food delivered have become common trends for many people. The consumption of food from unknown sources ...may impose an increased chance of contamination with microbiological hazards, especially if sanitary conditions are not met. We evaluated data from health surveillance agencies and scientific articles on foodborne diseases (FBD) reported internationally according to the exposure sites. We observed that the data are influenced by cultural, political, and socioeconomic differences. For instance, in New Zealand, Australia, United States, Denmark and India, the occurrence of FBD outbreaks was greater from foods prepared in commercial establishments and street vendors than from households. Conversely, in China, countries of the European Union and Brazil, the results are the opposite. Additionally, the pandemic imposed new eating behavior patterns, increasing delivery services and foods prepared in so-called “Dark Kitchens”. The underreporting and heterogeneity of data among countries prevented a precise conclusion to the question of whether homemade foods are inherently safer than foods prepared out. Nevertheless, a lower level of development in a country influences its sanitation conditions, as well as the number of street food vendors, the search for cheaper foods, and insufficient knowledge of the population on good hygiene practices, which can all increase the chances of FBD cases.
We examined in a prospective, randomized, international clinical trial the performance of a previously defined 30-gene predictor (DLDA-30) of pathologic complete response (pCR) to preoperative weekly ...paclitaxel and fluorouracil, doxorubicin, and cyclophosphamide (T/FAC) chemotherapy, and assessed if DLDA-30 also predicts increased sensitivity to FAC-only chemotherapy. We compared the pCR rates after T/FAC versus FACx6 preoperative chemotherapy. We also did an exploratory analysis to identify novel candidate genes that differentially predict response in the two treatment arms.
Two hundred and seventy-three patients were randomly assigned to receive either weekly paclitaxel × 12 followed by FAC × 4 (T/FAC, n = 138), or FAC × 6 (n = 135) neoadjuvant chemotherapy. All patients underwent a pretreatment fine-needle aspiration biopsy of the tumor for gene expression profiling and treatment response prediction.
The pCR rates were 19% and 9% in the T/FAC and FAC arms, respectively (P < 0.05). In the T/FAC arm, the positive predictive value (PPV) of the genomic predictor was 38% 95% confidence interval (95% CI), 21-56%, the negative predictive value was 88% (95% CI, 77-95%), and the area under the receiver operating characteristic curve (AUC) was 0.711. In the FAC arm, the PPV was 9% (95% CI, 1-29%) and the AUC was 0.584. This suggests that the genomic predictor may have regimen specificity. Its performance was similar to a clinical variable-based predictor nomogram.
Gene expression profiling for prospective response prediction was feasible in this international trial. The 30-gene predictor can identify patients with greater than average sensitivity to T/FAC chemotherapy. However, it captured molecular equivalents of clinical phenotype. Next-generation predictive markers will need to be developed separately for different molecular subsets of breast cancers.
Use of probiotic biofilms can be an alternative approach for reducing the formation of pathogenic biofilms in food industries. The aims of this study were (i) to evaluate the probiotic properties of ...bacteriocinogenic (Lactococcus lactis VB69, L. lactis VB94, Lactobacillus sakei MBSa1, and Lactobacillus curvatus MBSa3) and non-bacteriocinogenic (L. lactis 368, Lactobacillus helveticus 354, Lactobacillus casei 40, and Weissela viridescens 113) lactic acid bacteria (LAB) isolated from Brazilian's foods and (ii) to develop protective biofilms with these strains and test them for exclusion of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium. LAB were tested for survival in acid and bile salt conditions, surface properties, biosurfactant production, β-galactosidase and gelatinase activity, antibiotic resistance and presence of virulence genes. Most strains survived exposure to pH 2 and 4% bile salts. The highest percentages of auto-aggregation were obtained after 24 h of incubation. Sixty-seven percentage auto-aggregation value was observed in W. viridescens 113 and Lactobacillus curvatus MBSa3 exhibited the highest co-aggregation (69% with Listeria monocytogenes and 74.6% with E. coli O157:H7), while the lowest co-aggregation was exhibited by W. viridescens 113 (53.4% with Listeria monocytogenes and 38% with E. coli O157:H7). Tests for hemolytic activity, bacterial cell adherence with xylene, and drop collapse confirmed the biosurfactant-producing ability of most strains. Only one strain (L. lactis 368) produced β-galactosidase. All strains were negative for virulence genes cob, ccf, cylLL, cylLs, cyllM, cylB, cylA and efaAfs and gelatinase production. The antibiotic susceptibility tests indicated that the MIC for ciprofloxacin, clindamycin, gentamicin, kanamycin, and streptomycin did not exceed the epidemiological cut-off suggested by the European Food Safety Authority. Some strains were resistant to one or more antibiotics and resistance to antibiotics was species and strain dependent. In the protective biofilm assays, strains L. lactis 368 (bac-), Lactobacillus curvatus MBSa3 (bac+), and Lactobacillus sakei MBSa1 (bac+) resulted in more than six log reductions in the pathogens counts when compared to the controls. This effect could not be attributed to bacteriocin production. These results suggest that these potential probiotic strains can be used as alternatives for control of biofilm formation by pathogenic bacteria in the food industry, without conferring a risk to the consumers.
The growth parameters (growth rate, μ and lag time, λ) of three different strains each of Salmonella enterica and Listeria monocytogenes in minimally processed lettuce (MPL) and their changes as a ...function of temperature were modeled. MPL were packed under modified atmosphere (5% O2, 15% CO2 and 80% N2), stored at 7–30 °C and samples collected at different time intervals were enumerated for S. enterica and L. monocytogenes. Growth curves and equations describing the relationship between μ and λ as a function of temperature were constructed using the DMFit Excel add-in and through linear regression, respectively. The predicted growth parameters for the pathogens observed in this study were compared to ComBase, Pathogen modeling program (PMP) and data from the literature. High R2 values (0.97 and 0.93) were observed for average growth curves of different strains of pathogens grown on MPL. Secondary models of μ and λ for both pathogens followed a linear trend with high R2 values (>0.90). Root mean square error (RMSE) showed that the models obtained are accurate and suitable for modeling the growth of S. enterica and L. monocytogenes in MP lettuce. The current study provides growth models for these foodborne pathogens that can be used in microbial risk assessment.
► Modeling the growth of three different strains of Salmonella and L. monocytogenes. ► Primary and secondary modeling of growth rate and lag time in mix of lettuces. ► Salmonella grew faster than L. monocytogenes in the temperatures tested (7–30 °C). ► L. monocytogenes showed higher lag times at 7 and 10 °C than Salmonella enterica. ► Secondary modeling for both pathogens showed a linear trend with R2 values >0.90.
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