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1.
bioRxiv ; 2024 May 03.
Article in English | MEDLINE | ID: mdl-38746412

ABSTRACT

Forest edges, where humans, mosquitoes, and wildlife interact, may serve as a nexus for zoonotic arbovirus exchange. Although often treated as uniform interfaces, the landscape context of edge habitats can greatly impact ecological interactions. Here, we investigated how the landscape context of forest edges shapes mosquito community structure in an Amazon rainforest reserve near the city of Manaus, Brazil, using hand-nets to sample mosquitoes at three distinct forest edge types. Sampling sites were situated at edges bordering urban land cover, rural land cover, and natural treefall gaps, while sites in continuous forest served as controls. Community composition differed substantially among edge types, with rural edges supporting the highest species diversity. Rural edges also provided suitable habitat for forest specialists, including key sylvatic vectors, of which Haemagogus janthinomys was the most abundant species sampled overall. Our findings emphasize the importance of landscape context in assessing pathogen emergence risk at forest edges.

2.
Sensors (Basel) ; 24(7)2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38610438

ABSTRACT

This paper addresses the critical challenge of detecting, separating, and classifying partial discharges in substations. It proposes two solutions: the first involves developing a signal conditioning system to reduce the sampling requirements for PD detection and increase the signal-to-noise ratio. The second approach uses machine learning techniques to separate and classify PD based on features extracted from the conditioned signal. Three clustering algorithms (K-means, Gaussian Mixture Model (GMM), and Mean-shift) and the Support Vector Machine (SVM) method were used for signal separation and classification. The proposed system effectively reduced high-frequency components up to 50 MHz, improved the signal-to-noise ratio, and effectively separated different sources of partial discharges without losing relevant information. An accuracy of up to 93% was achieved in classifying the partial discharge sources. The successful implementation of the signal conditioning system and the machine learning-based signal separation approach opens avenues for more economical, scalable, and reliable PD monitoring systems.

3.
Sensors (Basel) ; 23(23)2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38067680

ABSTRACT

In this paper, the practical application of a bio-inspired antenna for partial discharge (PD) detection in high voltage equipment was evaluated in order to validate the efficiency of using this technology for PD monitoring purposes. For this, PD measurements using the bio-inspired antenna were performed on operational 69 kV potential transformers (PT) in a real substation. After the field experiment, laboratory measurements using the IEC 60270 standard method and a bio-inspired antenna were performed, simultaneously, over the evaluated PT. The results obtained at the substation indicated suspicious frequencies of partial discharge activity in two out of three evaluated potential transformers, mainly for the frequencies of 461 MHz, 1366 MHz, 1550 MHz and 1960 MHz. During the laboratory tests, the presence of partial discharge activity over the suspicious potential transformers was confirmed with the detection of PD apparent charge levels above 20 pC. Finally, the frequency spectrum obtained from the PD signals detected by the bio-inspired antenna in the laboratory presented similar frequency values to those obtained during the practical application at the substation, making it a promising indicator for future defect classification studies using artificial intelligence.

4.
PLoS Negl Trop Dis ; 17(4): e0011296, 2023 04.
Article in English | MEDLINE | ID: mdl-37099599

ABSTRACT

Risk of spillover and spillback of mosquito-borne viruses in the neotropics, including yellow fever, dengue, Zika (Flaviviridae: Flavivirus), chikungunya, and Mayaro (Togaviridae: Alphavirus) viruses, is highest at ecotones where humans, monkeys, and mosquitoes coexist. With a view to identifying potential bridge vectors, we investigated changes in mosquito community composition and environmental variables at ground level at distances of 0, 500, 1000, and 2000 m from the edge of a rainforest reserve bordering the city of Manaus in the central Brazilian Amazon. During two rainy seasons in 2019 and 2020, we sampled 9,467 mosquitoes at 244 unique sites using BG-Sentinel traps, hand-nets, and Prokopack aspirators. Species richness and diversity were generally higher at 0 m and 500 m than at 1000 m and 2000 m, while mosquito community composition changed considerably between the forest edge and 500 m before stabilizing by 1000 m. Shifts in environmental variables mainly occurred between the edge and 500 m, and the occurrence of key taxa (Aedes albopictus, Ae. scapularis, Limatus durhamii, Psorophora amazonica, Haemagogus, and Sabethes) was associated with one or more of these variables. Sites where Ae. aegypti and Ae. albopictus were detected had significantly higher surrounding mean NDBI (Normalized Difference Built-up Index) values than sites where they were not detected, while the opposite was true for Sabethes mosquitoes. Our findings suggest that major changes in mosquito communities and environmental variables occur within 500 m of the forest edge, where there is high risk for contact with both urban and sylvatic vectors. By 1000 m, conditions stabilize, species diversity decreases, and forest mosquitoes predominate. Environmental variables associated with the occurrence of key taxa may be leveraged to characterize suitable habitat and refine risk models for pathogen spillover and spillback.


Subject(s)
Aedes , Flavivirus , Zika Virus Infection , Zika Virus , Humans , Animals , Brazil , Mosquito Vectors , Forests , Ecosystem
5.
J Therm Biol ; 110: 103387, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36462849

ABSTRACT

Arboreal herbivores require large digestive tracts for leaf fermentation and detoxification; however, they must also have a low body mass that allows them to reach the foliage. The three-toed sloth, Bradypus tridactylus, experiences this trade-off, as leaves comprise 97.2% of its diet. Their calorie intake is extremely low owing to the low available caloric density of leaves and slow digestive processes related to leaf fibre fermentation and secondary compound detoxification. Sloths may require a high body temperature to assist fermentation; however, thermogenesis is energy-consuming. To investigate how sloths accomplish thermoregulation using marginal energy, we attached heart rate (HR) and temperature loggers to wild B. tridactylus individuals inhabiting the Amazon rainforest and recorded their HR and body surface temperature (Tskin). Tskin changed with ambient temperature (Ta) but was higher than Ta in 99.2% of cases. Increases in Tskin and HR did not coincide, suggesting that the increases were not caused by thermogenesis. Instead, they may passively increase Tskin by selecting warmer microhabitats and sunbathing. Consequently, 90.5% of Tskin were within 27.6-36.0 °C while the Ta fluctuated between 21.5 and 42.9 °C. This low-cost thermoregulation results in a low HR. In this study, the mean HR during observation was approximately 38.4% of the expected value based on the mammalian allometric relationship between body mass and HR. Thus, these properties may contribute to the low metabolic rates of sloths, alleviating their restricted energy intake.


Subject(s)
Sloths , Animals , Humans , Temperature , Heart Rate , Body Temperature Regulation , Thermogenesis
6.
Malar J ; 21(1): 343, 2022 Nov 17.
Article in English | MEDLINE | ID: mdl-36397077

ABSTRACT

BACKGROUND: The groundwork for malaria elimination does not currently consider the potential of Plasmodium zoonotic cycles that involve non-human primates (NHPs) in sylvatic environments. Since vivax malaria is less responsive to control measures, finding Plasmodium vivax infected NHPs adds even more concern. METHODS: Both Free-living monkeys in forest fragments inside the urban area and captive monkeys from a local zoo had blood samples tested for Plasmodium species. RESULTS: In this study, among the Neotropical monkeys tested, three (4.4%), one captive and two free-living, were found to be naturally infected by P. vivax. CONCLUSION: This important finding indicates that it is necessary to estimate the extent to which P. vivax NHP infection contributes to the maintenance of malaria transmission to humans. Therefore, the discussion on wildlife conservation and management must be incorporated into the malaria elimination agenda.


Subject(s)
Malaria, Vivax , Malaria , Plasmodium , Animals , Malaria, Vivax/prevention & control , Disease Eradication , Plasmodium vivax , Malaria/prevention & control
7.
Sci Rep ; 11(1): 21129, 2021 10 26.
Article in English | MEDLINE | ID: mdl-34702887

ABSTRACT

In the Americas, some mosquito-borne viruses such as Zika, chikungunya, and dengue circulate among humans in urban transmission cycles, while others, including yellow fever and Mayaro, circulate among monkeys in sylvatic cycles. The intersection of humans and wildlife at forest edges creates risk for zoonotic virus exchange. We built a scaffold tower at the edge of a treefall gap in rainforest bordering Manaus, Brazil, to identify vectors that may bridge transmission between humans and monkeys. We vertically sampled diurnally active, anthropophilic mosquitoes using handheld nets at 0, 5, and 9 m and container-breeding mosquitoes in ovitraps at 0, 5, 10, and 15 m. Haemagogus janthinomys and Psorophora amazonica were present in high relative abundance in nets at each height sampled, while anthropophilic species were uncommon in ovitraps. Hg. janthinomys was more abundant at elevated heights than at ground level, while Ps. amazonica abundance was not significantly stratified across heights. The presence of each species increased with increasing 7-day rainfall lagged at 1 week, and at 1 and 4 weeks prior to collection, respectively. In addition, Hg. janthinomys was most frequently collected at 29.9 °C, irrespective of height. These data provide insight into the potential role of each species as bridge vectors.


Subject(s)
Arboviruses , Culicidae/virology , Forests , Microclimate , Models, Biological , Mosquito Vectors/virology , Animals , Arboviruses/classification , Arboviruses/isolation & purification , Arboviruses/metabolism , Brazil , Culicidae/physiology , Haplorhini , Mosquito Vectors/physiology
8.
Viruses ; 13(10)2021 09 25.
Article in English | MEDLINE | ID: mdl-34696363

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the agent of coronavirus disease 2019 (COVID-19), is responsible for the worst pandemic of the 21st century. Like all human coronaviruses, SARS-CoV-2 originated in a wildlife reservoir, most likely from bats. As SARS-CoV-2 has spread across the globe in humans, it has spilled over to infect a variety of non-human animal species in domestic, farm, and zoo settings. Additionally, a broad range of species, including one neotropical monkey, have proven to be susceptible to experimental infection with SARS-CoV-2. Together, these findings raise the specter of establishment of novel enzootic cycles of SARS-CoV-2. To assess the potential exposure of free-living non-human primates to SARS-CoV-2, we sampled 60 neotropical monkeys living in proximity to Manaus and São José do Rio Preto, two hotspots for COVID-19 in Brazil. Our molecular and serological tests detected no evidence of SAR-CoV-2 infection among these populations. While this result is reassuring, sustained surveillance efforts of wildlife living in close association with human populations is warranted, given the stochastic nature of spillover events and the enormous implications of SARS-CoV-2 spillover for human health.


Subject(s)
COVID-19/epidemiology , Epidemiological Monitoring/veterinary , Primates/virology , Alouatta/virology , Animals , Animals, Wild/virology , Brazil/epidemiology , COVID-19/veterinary , Callicebus/virology , Callithrix/virology , Pandemics , SARS-CoV-2/pathogenicity , Viral Zoonoses/transmission
9.
Viruses, v. 13, n. 10, 1933, set. 2021
Article in English | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4035

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the agent of coronavirus disease 2019 (COVID-19), is responsible for the worst pandemic of the 21st century. Like all human coronaviruses, SARS-CoV-2 originated in a wildlife reservoir, most likely from bats. As SARS-CoV-2 has spread across the globe in humans, it has spilled over to infect a variety of non-human animal species in domestic, farm, and zoo settings. Additionally, a broad range of species, including one neotropical monkey, have proven to be susceptible to experimental infection with SARS-CoV-2. Together, these findings raise the specter of establishment of novel enzootic cycles of SARS-CoV-2. To assess the potential exposure of free-living non-human primates to SARS-CoV-2, we sampled 60 neotropical monkeys living in proximity to Manaus and São José do Rio Preto, two hotspots for COVID-19 in Brazil. Our molecular and serological tests detected no evidence of SAR-CoV-2 infection among these populations. While this result is reassuring, sustained surveillance efforts of wildlife living in close association with human populations is warranted, given the stochastic nature of spillover events and the enormous implications of SARS-CoV-2 spillover for human health.

10.
Sci Rep ; 10(1): 18254, 2020 10 26.
Article in English | MEDLINE | ID: mdl-33106507

ABSTRACT

The emergence of Zika virus (ZIKV) in Latin America brought to the fore longstanding concerns that forests bordering urban areas may provide a gateway for arbovirus spillback from humans to wildlife. To bridge urban and sylvatic transmission cycles, mosquitoes must co-occur with both humans and potential wildlife hosts, such as monkeys, in space and time. We deployed BG-Sentinel traps at heights of 0, 5, 10, and 15 m in trees in a rainforest reserve bordering Manaus, Brazil, to characterize the vertical stratification of mosquitoes and their associations with microclimate and to identify potential bridge vectors. Haemagogus janthinomys and Sabethes chloropterus, two known flavivirus vectors, showed significant stratification, occurring most frequently above the ground. Psorophora amazonica, a poorly studied anthropophilic species of unknown vector status, showed no stratification and was the most abundant species at all heights sampled. High temperatures and low humidity are common features of forest edges and microclimate analyses revealed negative associations between minimum relative humidity, which was inversely correlated with maximum temperature, and the occurrence of Haemagogus and Sabethes mosquitoes. In this reserve, human habitations border the forest while tamarin and capuchin monkeys are also common to edge habitats, creating opportunities for the spillback of mosquito-borne viruses.


Subject(s)
Animals, Wild/virology , Arbovirus Infections/transmission , Culicidae/virology , Mosquito Vectors/virology , Yellow Fever/transmission , Zika Virus Infection/transmission , Animals , Arbovirus Infections/virology , Arboviruses/isolation & purification , Arboviruses/pathogenicity , Brazil , Ecosystem , Flavivirus/isolation & purification , Flavivirus/pathogenicity , Forests , Haplorhini , Humans , Trees , Yellow Fever/virology , Zika Virus/isolation & purification , Zika Virus/pathogenicity , Zika Virus Infection/virology
11.
Anim Reprod Sci ; 214: 106305, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32087916

ABSTRACT

Scrotal circumference of bulls is correlated with pubertal age of female offspring. Hormonal control of reproductive function is similar in males and females, which may result in genetic correlation among different reproductive traits measured in the two sexes. The estimation of heritability and genetic correlations allows for the computation of direct and correlated genetic gains which are important for predicting of outcomes as a result of genetic-based selection. The aim of this study was to estimate genetic parameters and relative efficiency of indirect selection for age at first calving (AFC), stayability (STAY) and scrotal circumference at 365 days of age (SC365) in Nellore cattle. The STAY variable can be defined as the probability of a cow remain in the herd enough time to raise a certain number of calves that pay for her development and maintenance costs. A bivariate Bayesian analysis was used to estimate variance components using a linear-animal model for SC365 and AFC and threshold-linear model for SC365 and STAY and for AFC and STAY. For STAY, the value of 1 was assigned to cows that calved at least three times by 76 months of age; otherwise, the value 0 was assigned. The posteriori means of heritability estimates were 0.29, 0.08 and 0.09 for SC365, AFC and STAY, respectively. Genetic correlations were favorable from a cow productivity perspective between SC365 and AFC, and SC365 and STAY (-0.45 and 0.12, respectively). Indirect selection approaches were more efficient than direct selection for AFC (ERS = 1.87) when animals were selected for SC365.


Subject(s)
Cattle/genetics , Reproduction/genetics , Sexual Maturation/genetics , Animals , Bayes Theorem , Cattle/physiology , Male , Reproduction/physiology , Sexual Maturation/physiology
12.
Sensors (Basel) ; 19(19)2019 Sep 30.
Article in English | MEDLINE | ID: mdl-31575025

ABSTRACT

The adaptation of dielectric windows as metamaterial superstrate over a bio-inspired Printed Monopole Antenna (PMA) was evaluated in order to improve the detection sensitivity of Ultra High Frequency (UHF) sensors designed for Partial Discharge (PD) measurement. For this purpose, rectangular and circular Split Ring Resonators (SRR) structures were designed and evaluated aiming to achieve a metamaterial superstrate that improves the characteristics of the bio-inspired PMA as the gain, bandwidth, and radiation pattern. Measurements of the PMA with metamaterial superstrate were carried out in an anechoic chamber and compared to the simulations performed. The results show that the metamaterial superstrate insertion did not impact the original operating bandwidth, covering most of the characteristic frequency range of PD activity. Moreover, this insertion resulted in a mean gain enhancement of 0.7 dBi regarding the reference PMA, resulting in an antenna with better sensitivity for PD detection (mean gain of 3.61 dBi). The PMA-metamaterial set PD detection sensitivity was evaluated through laboratory tests with a point-to-plane PD generator setup and in field with measurements from a 230 kV current transformer. The developed PMA-metamaterial set was able to detect, successfully, the activity of PD for both tests, being classified as an optimized sensor for PD detection through dielectric windows.

13.
Sensors (Basel) ; 19(15)2019 Aug 05.
Article in English | MEDLINE | ID: mdl-31387324

ABSTRACT

This paper presents an algorithm for the localisation of partial discharge (PD) sourcesin power transformers based on the electromagnetic waves radiated by a PD pulse. The proposedalgorithm is more accurate than existing methods, since it considers the effects of the reflection,refractions and diffractions undergone by the ultra-high frequency (UHF) signal within the equipmenttank. The proposed method uses computational simulations of the electromagnetic waves generatedby PD, and obtains the time delay of the signal between each point in the 3D space and the UHFsensors. The calculated signals can be compared with the signals measured in the field, so thatthe position of the PD source can be located based on the best correlation between the simulatedpropagation delay and the measured data. The equations used in the proposed method are definedas a 3D optimisation problem, so that the binary particle swarm optimisation algorithm can be used.To test and demonstrate the proposed algorithm, computational simulations were performed. Thesolutions were sufficient to identify not only the occurrence of defects, but also the winding and theregion (top, centre or base) in which the defect occurred. In all cases, an accuracy of greater than15 cm was obtained for the location, in a 180 MVA three-phase transformer.

14.
Sensors (Basel) ; 19(3)2019 Feb 05.
Article in English | MEDLINE | ID: mdl-30764540

ABSTRACT

In this paper, the design and development of a bio-inspired UHF sensor for partial discharge detection in power transformers is presented. The UHF sensor was developed for external use in dielectric windows of power transformers. For this purpose, a microstrip antenna was designed with a radiating element shape based on the leaf of the Jatropha mollissima (Pohl) Baill plant. Then, an epoxy coating and an aluminium enclosure were developed to protect the antenna against corrosion and to provide mechanical support, external noise immunity, and a lifetime compatibility with power transformers. In order to verify the electrical parameters of the developed sensor, measurements of the gain and the reflection coefficient were performed in an anechoic chamber. Lastly, the antenna sensitivity for denominated partial discharge (PD) detection was compared with the IEC 60270 standard method. For this purpose, simultaneous tests were carried out in a partial discharge generator setup, composed of an oil cell with needle-plane electrodes. The experimental tests demonstrated the effectiveness of the sensor for detecting PD signals with apparent charge values higher than 35 pC.

15.
Sensors (Basel) ; 19(3)2019 Feb 01.
Article in English | MEDLINE | ID: mdl-30717243

ABSTRACT

A new, bio-inspired printed monopole antenna (PMA) model is applied to monitor partial discharge (PD) activity in high voltage insulating systems. An optimized sensor was obtained by designing a PMA in accordance with the characteristics of the electromagnetic signal produced by PD. An ultra-wideband (UWB) antenna was obtained by applying the truncated ground plane technique. The patch geometry was bio-inspired by that of the Inga Marginata leaf, resulting in a significant reduction in size. To verify the operating frequency and gain of the PMA, measurements were carried out in an anechoic chamber. The results show that the antenna operating bandwidth covers most of the frequency range of PD occurrence. Moreover, the antenna presented a good sensitivity (mean gain of 3.63 dBi). The antenna performance was evaluated through comparative results with the standard IEC 60270 method. For this purpose, simultaneous tests were carried out in a PD generator arrangement, composed by an oil cell with point-to-plane electrode configurations. The developed PMA can be classified as an optimized sensor for PD detection and suitable for substation application, since it is able to measure PD radiated signals with half the voltage levels obtained from the IEC method and is immune to corona discharges.

16.
Ciênc. rural ; 46(9): 1656-1661, tab, graf
Article in English | LILACS | ID: lil-787398

ABSTRACT

ABSTRACT: The aim of this research was to evaluate the dimensional reduction of additive direct genetic covariance matrices in genetic evaluations of growth traits (range 100-730 days) in Simmental cattle using principal components, as well as to estimate (co)variance components and genetic parameters. Principal component analyses were conducted for five different models-one full and four reduced-rank models. Models were compared using Akaike information (AIC) and Bayesian information (BIC) criteria. Variance components and genetic parameters were estimated by restricted maximum likelihood (REML). The AIC and BIC values were similar among models. This indicated that parsimonious models could be used in genetic evaluations in Simmental cattle. The first principal component explained more than 96% of total variance in both models. Heritability estimates were higher for advanced ages and varied from 0.05 (100 days) to 0.30 (730 days). Genetic correlation estimates were similar in both models regardless of magnitude and number of principal components. The first principal component was sufficient to explain almost all genetic variance. Furthermore, genetic parameter similarities and lower computational requirements allowed for parsimonious models in genetic evaluations of growth traits in Simmental cattle.


RESUMO: Objetivou-se estudar a efetividade da redução da dimensão da matriz de covariância do efeito genético direto na avaliação genética do crescimento (pesos dos 100 aos 730 dias de idade) de bovinos Simental, por meio da análise de componentes principais, e estimar componentes de (co)variância e parâmetros genéticos. A análise de componentes principais foi realizada ajsutando-se cinco diferentes modelos: um modelo multicaracterístico padrão, de posto completo, e quatro modelos de posto reduzido. Os modelos foram comparados via informação de Akaike (AIC) e informação Bayesiana de Schwarz (BIC). Os componentes de variância e parâmetros genéticos foram obtidos via REML. Os valores de AIC e BIC para os modelos testados foram similares, indicando a possibilidade da escolha de um modelo mais parcimonioso na avaliação genética da raça Simental. O primeiro componente principal explicou mais de 96% de toda variação genética aditiva direta em ambos os modelos. Os valores de herdabilidades foram maiores em idades mais avançadas e variaram de 0,05 (peso aos 100 dias) a 0,30 (peso aos 730 dias). As estimativas de correlações genéticas foram similares em todos os modelos e apresentaram mesma magnitude e comportamento independentemente do número de componentes principais adotado. Diante dos resultados, pode-se afirmar que apenas o primeiro componente principal foi suficiente para explicar quase que na totalidade a variação genética aditiva direta existente. Além disso, a similaridade dos parâmetros genéticos estimados e a menor demanda computacional são indicativos da possibilidade da utilização de modelos mais parcimoniosos na avaliação genética de bovinos Simental.

17.
J Contemp Dent Pract ; 17(2): 119-24, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-27206999

ABSTRACT

AIM: To evaluate the push-out bond strength (BS) of direct anatomic posts (DAPs) and conventional fiber posts (CFPs) cemented with different luting agents in different thirds of flared root canals. MATERIALS AND METHODS: A total of 60 human single-rooted canine teeth were transversally sectioned 16 mm from the radicular apex. After endodontic treatment, canals were flared with diamond burs. Samples were divided into six groups according to post type and luting agent: DAP and RelyX U100 (RXU); DAP and RelyX ARC (RXA); DAP and RelyX Luting 2 (RXL); CFP and RXU; CFP and RXA; CFP and RXL. Roots were sectioned transversely into six 1-mm-thick slices. The push-out test was performed and failure modes were observed. RESULTS: The DAP groups (7.23 ± 2.05) showed highest BS values (p < 0.05) when compared with CFP (5.93 ± 1.76). RelyX U100 (8.17 ± 1.70) showed higher BS values (p < 0.05) than RXA (6.46 ± 1.38), and RXL (5.10 ± 1.65) showed the lowest values. Bond strength on the apical third was statistically lower (p < 0.05) than that on the other thirds of the root canals. There was a predominance of adhesive failure for all groups. CONCLUSION: The DAPs improved retention in flared root canals, and RXU was the most effective luting agent. The apical third showed the lowest BS values. CLINICAL SIGNIFICANCE: The relining procedure of fiber posts with composite and the proper selection of luting resin cement are important for increasing bonding effectiveness in flared root canals.


Subject(s)
Dental Bonding/methods , Dental Cements , Dental Restoration, Permanent/instrumentation , Glass , Composite Resins , Cuspid , Dental Cements/chemistry , Dental Stress Analysis , Humans , In Vitro Techniques , Post and Core Technique , Root Canal Preparation , Tooth Root
18.
BMC Oral Health ; 14: 91, 2014 Jul 18.
Article in English | MEDLINE | ID: mdl-25037704

ABSTRACT

BACKGROUND: This study assessed the prevalence of traumatic dental injuries (TDI) and its association with sociodemographic and physical characteristics in the anterior permanent teeth of 12-year-old schoolchildren at the city of Brasília - DF, Brazil. METHODS: A cross-sectional, population-based study was conducted on a sample of 1,389 boys and girls aged 12 years, enrolled in public and private fundamental schools at the Administrative Region (RA) of Brasília, Brazil, from October 2011 to September 2012. The demographic details were achieved by a structured questionnaire. The study recorded the type of damage, the size of incisal overjet, and whether lip coverage was inadequate. Sociodemographic data included sex, income and educational level of the parents or caretakers. RESULTS: A total of 1118 schoolchildren were examined, yielding a response rate of 80.48%. The prevalence of TDI was 14.63% in public schools and 23.40% in private schools. The students did not differ according to sex, income and educational level of the parents or caretakers concerning the occurrence of traumas in permanent anterior teeth. Increased overjet and inadequate lip coverage were found to be important contributing factors for TDIs. CONCLUSION: In conclusion, this study showed an expressive prevalence of TDI in 12-year-old in schoolchildren at Brasília DF, Brazil. Sex and educational level of the parents were not associated with trauma. The increased overjet and inadequate lip coverage were significantly associated with dental trauma.


Subject(s)
Tooth Injuries/epidemiology , Brazil/epidemiology , Causality , Child , Cross-Sectional Studies , Cuspid/injuries , Educational Status , Female , Health Knowledge, Attitudes, Practice , Household Articles , Housing , Humans , Incisor/injuries , Income , Lip/anatomy & histology , Male , Overbite/epidemiology , Parents/education , Population Surveillance , Prevalence , Sex Factors , Socioeconomic Factors
19.
Article in English | MEDLINE | ID: mdl-23220682

ABSTRACT

In this paper we have studied the 4-hydroxyl-2,5 dimethylphenyl-benzophenone. Also, it was analyzed the vibrational assignment (FT-IR and Raman) in conjunction with computational results. The conformational analysis showed three barrier heights where two are due to the dihedral rotation and the other one is attributed to hydroxyl rotation. While the high dihedral rotational barrier (TS1) is 6.06-7.22 kcal mol(-1), the lower one (TS2) is almost three times smaller. The variations with the change of basis set is 5-8% to TS1, and 3-15% in the values predicted to TS2. In the case of OH rotational barrier, the values range from 3.70 to 4.86 kcal mol(-1), and it is also observed that this transition state is less sensitive to the change of basis set and to the method. Two isomers was detected due to the changes in the OH rotation with the gap energy lower than 0.7 kcal mol(-1), and at this point is seen that semi-empirical methods fail into describe the most stable conformation which may be due to the small energy gap. The enthalpy formation at 0 K and 298 K was 111.71 and 102.20 kcal mol(-1), respectively.


Subject(s)
Benzophenones/chemistry , Sunscreening Agents/chemistry , Models, Molecular , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Thermodynamics
20.
J. Health Sci. Inst ; 28(1)jan.-mar. 2010.
Article in Portuguese | LILACS | ID: lil-652264

ABSTRACT

Cistos são lesões odontogênicas benignas que podem atingir grandes dimensões e mais comuns nos maxilares. Apesar do crescimento lento e contínuo caracterizar qualquer tipo de cisto, o queratocisto odontogênico chama atenção por ser mais agressivo e altamente recidivante (o índice de recidiva varia de 22% a 60%). A faixa etária de ocorrência do ceratocisto é ampla e impossível de se determinar, não havendo predileção quanto ao gênero do paciente. Sua localização típica é a região posterior de mandíbula, incluindo ângulo e ramo. Radiograficamente se apresenta radiolúcido e bem delimitado. O padrão unilocular predomina sobre o padrão multilocular. O ceratocisto ou queratocisto odontogênico é considerado atualmente um tumor odontogênico, devido à sua agressividade, potencial de crescimento, natureza neoplásica e alto índice de recorrência. Portanto, a denominação correta e atual para esta lesão é Tumor Odontogênico Queratocístico.


Cysts are benign odontogenic lesions which can reach large dimensions and most common in jaws. Despite the slow growth and continued characterize any type of cyst, the odontogenic keratocyst calls attention for being more aggressive and highly recurrent (the recurrence rate varies from 22% to 60%). The age of occurrence of the keratocyst is wide and impossible to determine, with no preference regarding gender of the patient. Its typical location is the posterior mandible, including angle and ramus. Radiographicaly is radiolucent and well defined.The pattern unilocular predominates over the standard multilocular. The keratocyst or odontogenic keratocyst is currently considered an odontogenic tumor, due to its aggressiveness, growth potential, neoplastic nature and high recurrence rate. Therefore, the correct name and current for this lesion is Keratocystic Odontogenic Tumour.

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