45 resultados para improving competitive ability
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Purpose - Application of the horizontal alliance paradigm has particularly relevance to small retailers. It is a powerful mechanism for independents and non-integrated chain retailers to develop competitive advantage, maintaining and improving their performance. The purpose of this article is to analyse the theory of alliance in the context of the retail sector. Design/methodology/approach - Both quantitative and qualitative research was carried out with horizontal retail alliances in Brazil. Findings - Focusing on the alliances among independents and non-integrated chain retailers, our discussion covers specifically the following issues: the reasons for forming a strategic alliance in retail; minimum criteria for the alliance activity amongst retailers; steps that managers must take to create a competitive retail alliance; critical core competencies to be developed on the retail alliance; types of retail alliances; and, finally, forms of strategic retail alliances and stages/steps to develop a retail alliance over time. Research limitations/implications - The study considers horizontal alliances in a Brazilian retail context, which is in some ways unique, however, key principles and findings are very much transferable. Practical implications/implications - The study is of value not only to researchers of retail horizontal alliances, but offers retail practitioners specific experience and guidance. Originality/value - It was identified from the literature that there have been relatively few theoretical and practical studies available that analyse the relationship between the outlined themes concerned with alliances and small retailers. The discussion in our paper provides useful information and new insights to both academics and practitioners.
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Recent advances in the control of molecular engineering architectures have allowed unprecedented ability of molecular recognition in biosensing, with a promising impact for clinical diagnosis and environment control. The availability of large amounts of data from electrical, optical, or electrochemical measurements requires, however, sophisticated data treatment in order to optimize sensing performance. In this study, we show how an information visualization system based on projections, referred to as Projection Explorer (PEx), can be used to achieve high performance for biosensors made with nanostructured films containing immobilized antigens. As a proof of concept, various visualizations were obtained with impedance spectroscopy data from an array of sensors whose electrical response could be specific toward a given antibody (analyte) owing to molecular recognition processes. In addition to discussing the distinct methods for projection and normalization of the data, we demonstrate that an excellent distinction can be made between real samples tested positive for Chagas disease and Leishmaniasis, which could not be achieved with conventional statistical methods. Such high performance probably arose from the possibility of treating the data in the whole frequency range. Through a systematic analysis, it was inferred that Sammon`s mapping with standardization to normalize the data gives the best results, where distinction could be made of blood serum samples containing 10(-7) mg/mL of the antibody. The method inherent in PEx and the procedures for analyzing the impedance data are entirely generic and can be extended to optimize any type of sensor or biosensor.
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There is not a specific test to diagnose Alzheimer`s disease (AD). Its diagnosis should be based upon clinical history, neuropsychological and laboratory tests, neuroimaging and electroencephalography (EEG). Therefore, new approaches are necessary to enable earlier and more accurate diagnosis and to follow treatment results. In this study we used a Machine Learning (ML) technique, named Support Vector Machine (SVM), to search patterns in EEG epochs to differentiate AD patients from controls. As a result, we developed a quantitative EEG (qEEG) processing method for automatic differentiation of patients with AD from normal individuals, as a complement to the diagnosis of probable dementia. We studied EEGs from 19 normal subjects (14 females/5 males, mean age 71.6 years) and 16 probable mild to moderate symptoms AD patients (14 females/2 males, mean age 73.4 years. The results obtained from analysis of EEG epochs were accuracy 79.9% and sensitivity 83.2%. The analysis considering the diagnosis of each individual patient reached 87.0% accuracy and 91.7% sensitivity.
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Streptococcus pyogenes infections remain a health problem in several countries due to poststreptococcal sequelae. We developed a vaccine epitope (StreptInCor) composed of 55 amino acids residues of the C-terminal portion of the M protein that encompasses both T and B cell protective epitopes. The nuclear magnetic resonance (NMR) structure of the StreptInCor peptide showed that the structure was composed of two microdomains linked by an 18-residue alpha-helix. A chemical stability study of the StreptInCor folding/unfolding process using far-UV circular dichroism showed that the structure was chemically stable with respect to pH and the concentration of urea. The T cell epitope is located in the first microdomain and encompasses 11 out of the 18 alpha-helix residues, whereas the B cell epitope is in the second microdomain and showed no alpha-helical structure. The prediction of StreptInCor epitope binding to different HLA class II molecules was evaluated based on an analysis of the 55 residues and the theoretical possibilities for the processed peptides to fit into the P1, P4, P6, and P9 pockets in the groove of several HLA class II molecules. We observed 7 potential sites along the amino acid sequence of StreptInCor that were capable of recognizing HLA class II molecules (DRB1*, DRB3*, DRB4*, and DRB5*). StreptInCoroverlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules and could be considered as a universal vaccine epitope.
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This study evaluated the effects of a micro cycle of overload training (1st-8th day) on metabolic and hormonal responses in male runners with or without carbohydrate supplementation and investigated the cumulative effects of this period on a session of intermittent high-intensity running and maximum-performance-test (9th day). The participants were 24 male runners divided into two groups, receiving 61% of their energy intake as CHO (carbohydrate-group) and 54% in the control-group (CON). The testosterone was higher for the CHO than the CON group after the overload training (694.0 +/- A 54.6 vs. CON 610.8 +/- A 47.9 pmol/l). On the ninth day participants performed 10 x 800 m at mean 3 km velocity. An all-out 1000 m running was performed before and after the 10 x 800 m. Before, during, and after this protocol, the runners received solution containing CHO or the CON equivalent. The performance on 800 m series did not differ in either group between the first and last series of 800 m, but for the all-out 1000 m test the performance decrement was lower for CHO group (5.3 +/- A 1.0 vs. 10.6 +/- A 1.3%). The cortisol concentrations were lower in the CHO group in relation to CON group (22.4 +/- A 0.9 vs. 27.6 +/- A 1.4 pmol/l) and the IGF1/IGFBP3 ratio increased 12.7% in the CHO group. During recovery, blood glucose concentrations remained higher in the CHO group in comparison with the CON group. It was concluded that CHO supplementation possibly attenuated the suppression of the hypothalamic-pituitary-gonadal axis and resulted in less catabolic stress, and thus improved running performance.
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The aim of this study was to test the hypothesis that bone marrow mononuclear cell (BMDMC) therapy led an improvement in lung mechanics and histology in endotoxin-induced lung injury. Twenty-four C57BL/6 mice were randomly divided into four groups (n = 6 each). In the acute lung injur;y (ALI) group, Escherichia coli lipopolysaccharide (LPS) was instilled intratracheally (40 mu g, IT), and control (C) mice received saline (0.05 ml, IT). One hour after the administration of saline or LPS, BMDMC (2 x 10(7) cells) was intravenously injected. At day 28, animals were anesthetized and lung mechanics [static elastance (E(st)), resistive (Delta P(1)), and viscoelastic (Delta P(2)) pressures] and histology (light and electron microscopy) were analyzed. Immunogold electron microscopy was used to evaluate if multinucleate cells were type II epithelial cells. BMDMC therapy prevented endotoxin-induced lung inflammation, alveolar collapse, and interstitial edema. In addition, BMDMC administration led to epithelial and endothelial repair with multinucleated type II pneumocytes. These histological changes yielded a reduction in lung E(st), Delta P(1), and Delta P(2) compared to ALI. In the present experimental ALI model, the administration of BMDMC yielded a reduction in the inflammatory process and a repair of epithelium and endothelium, reducing the amount of alveolar collapse, thus leading to an improvement in lung mechanics.
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Purpose: We tested whether the combination of 4 established cell cycle regulators (p53, pRB, p21 and p27) could improve the ability to predict clinical outcomes in a large multi-institutional collaboration of patients with pT3-4N0 or pTany Npositive urothelial carcinoma of the bladder. We also assessed whether the combination of molecular markers is superior to any individual biomarker. Materials and Methods: The study comprised 692 patients with pT3-4N0 or pTany Npositive urothelial carcinoma of the bladder treated with radical cystectomy and bilateral lymphadenectomy (median followup 5.3 years). Scoring was performed using advanced cell imaging and color detection software. The base model incorporated patient age, gender, stage, grade, lymphovascular invasion, number of lymph nodes removed, number of positive lymph nodes, concomitant carcinoma in situ and adjuvant chemotherapy. Results: Individual molecular markers did not improve the predictive accuracy for disease recurrence and cancer specific mortality. Combination of all 4 molecular markers into number of altered molecular markers resulted in significantly 1 higher predictive accuracy than any single biomarker (p < 0.001.). Moreover addition of number of altered molecular markers to the base model significantly improved the predictive accuracy for disease recurrence (3.9%, p < 0.001) and cancer specific mortality (4.3%, p < 0.001). Addition of number of altered molecular markers retained statistical significance for improving the prediction of clinical outcomes in the subgroup of patients with pT3N0 (280), pT4N0 (83) and pTany Npositive (329) disease (p < 0.001). Conclusions: While the status of individual molecular markers does not add sufficient value to outcome prediction in patients with advanced urothelial carcinoma of the bladder, combinations of molecular markers may improve molecular staging, prognostication and possibly prediction of response to therapy.
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Animals inheriting the slick hair gene have a short, sleek, and sometimes glossy coat. The objective of the present study was to determine whether slick-haired Holstein cows regulate body temperature more effectively than wild-type Holstein cows when exposed to an acute increase in heat stress. Lactating slick cows (n = 10) and wild-type cows (n = 10) were placed for 10 h in an indoor environment with a solid roof, fans, and evaporative cooling or in an outdoor environment with shade cloth and no fans or evaporative cooling. Cows were exposed to both environments in a single reversal design. Vaginal temperature, respiration rate, surface temperature, and sweating rate were measured at 1200, 1500, 1800, and 2100 h (replicate 1) or 1200 and 1500 h (replicate 2), and blood samples were collected for plasma cortisol concentration. Cows in the outdoor environment had higher vaginal and surface temperatures, respiration rates, and sweating rates than cows in the indoor environment. In both environments, slick-haired cows had lower vaginal temperatures (indoor: 39.0 vs. 39.4 degrees C; outdoor 39.6 vs. 40.2 degrees C; SEM = 0.07) and respiration rate (indoor: 67 vs. 79 breaths/min; outdoor 97 vs. 107 breaths/min; SEM = 5.5) than wild-type cows and greater sweating rates in unclipped areas of skin (indoor: 57 vs. 43 g.h(-1)/m(2); outdoor 82 vs. 61 g.h(-1)/m(2); SEM = 8). Clipping the hair at the site of sweating measurement eliminated the difference between slick-haired and wild-type cows. Results indicate that slick-haired Holstein cows can regulate body temperature more effectively than wild-type cows during heat stress. One reason slick-haired animals are better able to regulate body temperature is increased sweating rate.
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This study aimed to test the hypothesis that dentine alterations induced by 810 nm-diode laser may affect the interaction between root canal sealers and the dentin wall. Seventy-two single root human teeth were selected and root canals were enlarged with K-files. Dentine was treated with 0.5% NaOCl and 17% EDTA-T and irradiated (laser group) by diode laser (810 nm/P = 2.5W/I = 1989 W/cm(2)) or remained non-irradiated (control group). Six samples per group were analyzed by scanning electron microscopy (SEM). The remaining samples of each group were divided into three subgroups (n = 10) and sealed with one of the tested sealers (N-Rickert/AHPlus (TM)/Apexit (R)). Apical leakage was estimated by evaluating penetration of 0.5% methylene-blue dye. SEM analysis revealed that dentine at the apical third in irradiated samples was melted and fusioned whereas non-irradiated samples exhibited opened dentinal tubules. Despite the morphological changes induced by irradiation, laser did not affect the sealing ability of N-Rickert and AHPlus (TM) sealers. However, the length of apical leakage in roots filled with Apexit (R) was lower in irradiated root canals than in non-irradiated samples (p < 0.05). Morphological changes of root canal walls promoted by diode laser irradiation may improve de sealing ability of Apexit (R), a calcium hydroxide-based sealer, suggesting that improved sealing promoted by irradiation may represent an additional factor contributing to the endodontic clinical outcome.
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Introduction: There is ongoing debate regarding the ideal sequence, volume, and concentration of irrigants, length of time for irrigation, and irrigation technique to achieve debridement of the root canal system. The aim of this study was to verify the impact of the final rinse technique on smear layer removal ability of 17% ethylenediaminetetraacetic acid (EDTA). Methods: Sixteen single-rooted human teeth were instrumented and divided into 2 groups at the final rinse step according to the following final rinse techniques used: continuous rinse group, continuous rinse with EDTA during 3 minutes, and rinse and soaking group, rinse with 1 mL of EDTA, soaking of the canal for 2 minutes and 30 seconds, and rinse completion with the remaining 4 mL for 30 seconds. The specimens were split lengthwise and observed under scanning electron microscope. Results: Data were analyzed with Kruskal-Wallis and Dunn tests. The continuous rinse group presented more debris-free surfaces when compared with the rinse and soaking group (P <. 01). When the root canal areas were compared within the groups, no statistical differences were found (P > .05). Conclusions: It can be concluded that a continuous rinse with 5 mL of EDTA for 3 minutes can more efficiently remove the smear layer from root canal walls. (J Endod 2010;36:512-514)
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Introduction: This ex vivo study evaluated the heat release, time required, and cleaning efficacy of MTwo (VDW, Munich, Germany) and ProTaper Universal Retreatment systems (Dentsply/Maillefer, Ballaigues, Switzerland) and hand instrumentation in the removal of filling material. Methods: Sixty single-rooted human teeth with a single straight canal were obturated with gutta-percha and zinc oxide and eugenol-based cement and randomly allocated to 3 groups (n = 20). After 30-day storage at 37 degrees C and 100% humidity, the root fillings were removed using ProTaper UR, MTwo R, or hand files. Heat release, time required, and cleaning efficacy data were analyzed statistically (analysis of variance and the Tukey test, alpha = 0.05). Results: None of the techniques removed the root fillings completely. Filling material removal with ProTaper UR was faster but caused more heat release. Mtwo R produced less heat release than the other techniques but was the least efficient in removing gutta-percha/sealer. Conclusions: ProTaper UR and MTwo R caused the greatest and lowest temperature increase on root surface, respectively; regardless of the type of instrument, more heat was released in the cervical third. Pro Taper UR needed less time to remove fillings than MTwo R. All techniques left filling debris in the root canals. (I Endod 2010;36:1870-1873)
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Introduction: The aim of this study was to evaluate the biofilm dissolution and cleaning ability of different irrigant solutions on intraorally infected dentin. Methods: One hundred twenty bovine dentin specimens were infected intraorally by using a removable orthodontic device. Thirty samples were used for each irrigant solution: 2% chlorhexidine and 1%, 2.5%, and 5.25% sodium hypochlorite (NaOCl). The solutions were used for 5, 15, and 30 minutes and at 2 experimental volumes, 500 mu L and 1 mL. The samples were stained by using acridine orange dye before and after the experiments and evaluated by using a confocal microscope. The percentage of biofilm, isolated cells, and noncolonized dentin was measured by using a grid system. Differences in the reduction or increase of the studied parameters were assessed by using nonparametric methods (P < .05). Results: The higher values of biofilm dissolution and noncolonized dentin were found in the 30-minute NaOCl group and in the 5-minute and 15-minute groups of 5.25% NaOCL. The use of 2% chlorhexidine solution did not improve the biofilm dissolution or increase the cleaning of the dentin in comparison with the NaOCl solutions (P < .05). Conclusions: Two percent chlorhexidine does not dissolve the biofilms. Thirty minutes of NaOCl are necessary to have higher values of biofilm dissolution and to increase the cleaning of the dentin independently of the concentration in comparison with the 5-minute and 15-minute contact times. (J Endod 2011;37:1134-1138)
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Objective: To evaluate whether the type of cola drink (regular or diet) could influence the wear of enamel subjected to erosion followed by brushing abrasion, Method and !Materials: Ten volunteers wore intraoral devices that each had eight bovine enamel blocks divided into four groups; ER, erosion with regular cola; EAR, erosion with regular cola plus abrasion; EL, erosion with light cola; and EAL, erosion with light cola plus abrasion, Each day for 1 week, half of each device was immersed in regular cola for 5 minutes, Then, two blocks were brushed using a fluoridated toothpaste and electric toothbrush for 30 seconds four times daily, Immediately after, the other half of the device was subjected to the same procedure using a light cola, The pH, calcium, phosphorus, and fluoride concentrations of the colas were analyzed using standard procedures, Enamel alterations were measured by profilometry. Data were tested using two-way ANOVA and Bonferroni test (P < .05), Results: Regarding chemical characteristics, light cola presented pH 3.0, 13.7 mg Ca/L, 15.5 mg P/L, and 0.31 mg F/L, while regular cola had pH 2.6, 32.1 mg Ca/L, 1:8.1 mg P/L, and 0.26 mg F/L, The light cola promoted less enamel loss (EL, 0.36 pm; EAL, 0.39 pm) than its regular counterpart (ER, 0.72 pm; EAR, 0.95 pm) for both conditions, There was not a significant difference (P > .05) between erosion and erosion plus abrasion for light cola, However, for regular cola, erosion plus abrasion resulted in higher enamel loss than erosion alone,.nclusion: The data suggest that light cola promoted less enamel wear even when erosion was followed by brushing abrasion, (Quintessence Int 2011;42:xxx-xx)()
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Evaluate, through computerized tomography, canal transportation and centring ability of RaCe rotary instruments after preparation of mesiobuccal root canals in maxillary molar teeth. Twenty-seven teeth were submitted to three cone beam tomographic analyses, one preoperatively, and two after preparation with file size 35, .02 taper and size 50, .02 taper. Canal transportation and centring ability were measured with reference to the distance between the noninstrumented portion of the root canals and the mesial and distal periphery of the root, compared with images obtained after the preparation with size 35 and 50 instruments. Canal transportation after preparation with the size 35 file was 0.030 +/- 0.253 mm and after the size 50 file was 0.057 +/- 0.317 mm. The centring ratio values after preparation with the size 35 file was 0.42 +/- 0.32 and after the size 50 file was 0.54 +/- 0.29, with no significant statistical difference between the groups. RaCe instruments allowed the preparation of curved root canals with preparation diameters larger than those normally used with minimal canal transportation and adequate centring ability.
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Objective. To evaluate the influence of shaft design on the shaping ability of 3 rotary nickel-titanium (NiTi) systems. Study design. Sixty curved mesial canals of mandibular molars were used. Specimens were scanned by spiral tomography before and after canal preparation using ProTaper, ProFile, and ProSystem GT rotary instruments. One-millimeter-thick slices were scanned from the apical end point to the pulp chamber. The cross-sectional images from the slices taken earlier and after canal preparation at the apical, coronal, and midroot levels were compared. Results. The mean working time was 137.22 +/- 5.15 s. Mean transportation, mean centering ratio, and percentage of area increase were 0.022 +/- 0.131 mm, 0.21 +/- 0.11, and 76.90 +/- 42.27%, respectively, with no statistical differences (P > .05). Conclusions. All instruments were able to shape curved mesial canals in mandibular molars to size 30 without significant errors. The differences in shaft designs seemed not to affect their shaping capabilities.