Universidade Positivo

About: Universidade Positivo is a education organization based out in Curitiba, Brazil. It is known for research contribution in the topics: Population & Medicine. The organization has 1290 authors who have published 1237 publications receiving 9335 citations. The organization is also known as: Positive University.

Effects of active oxygen toothpaste in supragingival biofilm reduction: A randomized controlled clinical trial

Abstract: Gingivitis is still considered a major risk factor for the occurrence and progression of periodontal disease. The aim of the present study was to compare the long-term (1, 12, and 18 weeks) antiplaque and antigingivitis efficacies of two commercially available toothpastes, Colgate Total® (CT) and BlueM® (BM), against attached supragingival dental plaque and gingival inflammation in an experimental gingivitis model. A parallel double-blinded randomized clinical trial including 39 dental students who refrained from all plaque control methods (manual or chemical) for 7 days was conducted. After the establishment of clinical gingivitis, participants were randomized into two experimental groups (CT and BM). Plaque index (PI) and gingival index (GI) were then calculated according to Turesky’s modified Quigley and Hein index. Participants were assessed in four time periods (preclinical trial phase (W −1), gingivitis phase (W0), one week (W1), twelve weeks (W12), and eighteen weeks (W18)). Participants’ stimulated saliva was collected and cultured (either aerobically or anaerobically, 37°C, 48 hours) in each time period (W −1, W0, W1, W12, and W18) for the count of viable colonies. Obtained data were analyzed using 2-way ANOVA and Tukey’s test (α = 0.05). No significant differences were found ( ) between experimental groups at W −1. Significant differences between groups were observed at W0 ( ) for the parameter time period, but not for the interaction between parameters (time period toothpastes). Lower bacterial counts were observed in both groups after one week of toothbrushing; however, no significant differences were found between investigated dentifrices. Intra- and intergroup comparisons revealed that significant differences were not found ( ) between dentifrices at W1, W12, and W18 for both GI and PI. The present study demonstrated that toothpastes containing active oxygen and lactoferrin (BM) have comparable antiplaque and antigingivitis efficacies with triclosan-containing toothpastes (CT).

Color Stability of Ceramic Veneers Luted With Resin Cements and Pre-Heated Composites: 12 Months Follow-Up.

Abstract: The objective was to evaluate the color stability of ceramic veneers luted with resin cements and pre-heated composite resins (60oC) for 12 months, and determine the degree of conversion (DC) of the luting agents. Two resin cements (AllCem Veneer, light-cured (LRC) and AllCem, dual-cured (DRC)] and three composite resins [Z100 (MNCR-minifilled), Herculite Classic (MHCR-micro-hybrid) and Durafill (MCCR-microfilled)] were used for cementing 0.8-mm-thick lithium-silicate glass-ceramic laminates (Suprinity, shade B2-HT, Vita) on bovine enamel (n=10). The specimens were stored at 37oC in distilled water. CIELab parameters were determined at 24h after luting (baseline), 7, 30, 90, 180 days and 12 months. Three specimens were prepared for DC evaluation, performed by micro-Raman spectroscopy. Data were analyzed by ANOVA and Tukey's test (a=5%). For ΔEab and ΔE00, there were significant differences for luting material (p<0.001), time (p<0.001), and double interaction (p<0.001). The groups cemented with MHCR (1 year), MCCR (90 days and 1 year) and MCCR-PH (1 year) were the ones with ΔE values greater than the acceptability threshold. All other groups maintained their ΔE lower than the acceptability threshold after 1 year in distilled water. Regarding DC, there were no significant differences (p=0.127) among the materials. Non-significant negative correlations were observed between the mean ΔEab and DC (R=-0.65) and ΔE00 and DC (R=-0.64). A significant positive correlation was observed mean ΔEab and ΔE00 (R=0.99). It was concluded that the different luting agents influenced the final color of the restorations. The heating of the composite resins did not affect their DC.

CFD modelling of helically coiled tube flocculators for velocity gradient assessment

Abstract: Helical tubes are used as reactors in applications such as food processing and water and wastewater treatment. In water and wastewater treatment plants, helically coiled tube flocculators (HCTFs) provide efficiency gains over the more traditionally used baffled tanks. Their superior performance has been credited to more favourable velocity gradients (G) but detailed fluid dynamics information on the response of such reactors to varying design and operational conditions is still lacking. In this study, three-dimensional computational fluid dynamics (CFD) simulations were conducted to address this shortcoming. A validated CFD model of HCTFs was applied to assess the impact of varying reactor diameter and operating flow rate on the distributions of G, axial velocity and secondary flow structures. The developed flow region of the reactor was characterised for the occurrence and corresponding response of two cross-section zones, which govern the reactor efficiency. An equation is proposed associating G with a normalised parameter involving the reactor torsion, curvature and Reynolds number, which can be used to support the rational design, optimisation and operation control of HCTFs.

Management of Contacts of Patients With Severe Invasive Group A Streptococcal Infection.

Abstract: Background Conflicting recommendations regarding antibiotic prophylaxis for contacts of patients with invasive group A streptococcal (GAS) infection exist. Close contacts of patients with such severe and rapidly progressive disease often strongly appeal to the treating clinicians for antimicrobial treatment to prevent additional cases. We aimed to use an approach based on pharyngeal culture testing of contacts and targeted antibiotic prophylaxis. Methods A large throat swab survey including 105 contacts was undertaken after a fulminant and fatal case of GAS necrotizing fasciitis. GAS strains were characterized by emm typing and antimicrobial susceptibility to 7 antibiotics. The presence of 30 virulence determinants was determined by polymerase chain reaction and sequencing. Results The GAS isolate recovered from the index patient was an M1T1 GAS clone susceptible to all antimicrobial agents tested. The same clone was present in the throat of 36% of close contacts who had exposure to the index patient (family households and classroom contacts) for >24 hours/week, whereas the strain was present in only 2% of the other contacts. Conclusions Although the study does not allow firm conclusions to be drawn as to whether antibiotic prophylaxis is effective, we describe a practical approach, including an educational campaign and targeted antibiotic treatment to close contacts who have been exposed to an index patient for > 24 hours/week before the initial disease onset.

Decolonising transitions in the Global South: Towards more epistemic diversity in transitions research

Abstract: Research on sustainability transitions in the Global South has evolved since its inception a decade ago. Yet, many issues concerning the hegemony of Western knowledge systems and practices continue to impact research on transitions in the Global South. This viewpoint suggests several ways to address these issues through decolonialising transitions research: namely through acknowledging everyday struggles faced in the Global South, explicitly addressing questions of power, informal institutions, inequality and injustice that permeate transitions in the Global South and integrating truly participatory research methods that value research ‘subjects’ and embrace the transformative activities and communities of practices. Drawing on half a decade of formal and informal knowledges exchanges led by “Transitions in the Global South” thematic group of STRN, it is time for our community to embrace a fresh and alternative approach to understanding, mainstreaming and implementing transitions in the Global South.