41 research outputs found

    Effect of DLC Coating on Tribological Behavior of Cylinder Liner-piston Ring Material Combination When Lubricated with Jatropha Oil

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    AbstractThe expansion of modern engines would have been unfeasible without advanced lubricant chemistry and proper lubricant formulation. Introduction of diamond like carbon (DLC) coatings opens further possibilities in improving performance of engine and transmission components, which cannot longer be achieved only by lubricant design.DLC coatings show extremely good promise for a number of applications in automotive components as they exhibit excellent tribological properties. In this paper, the tribological performance of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil was evaluated using a four ball Tribometer also with commercial synthetic lubrication oil (SAE 40) used as base lubricant. Experimental results demonstrated that the hydrogenated amorphous carbon (a-C: H)DLC coating exhibited better performance with Jatropha oil in terms of wear and friction under similar operating conditions compared to the uncoated stainless. Thus, usage of hydrogenated amorphous carbon (a-C: H)DLC coating with Jatropha oil in the long run may have a positive impact on engine life

    Intra-abdominal Pressure is Influenced by Body Position?

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    Abstract Background: Increased intra-abdominal pressure (IAP) is a complication related to physio pathological changes with high rates of mortality and morbidity. Abdominal surgery is consider one of the risk factors that can increased IAP. Measurement can be done by direct or indirect methods, being the most used the transurethral (TM). However this method continues to generate some controversy. This study tries to clarify the doubts of the effect of body position when we use different methods to measure IAP. Methodology: Study realized an anatomical model in order to eliminate the described variables that influence IAP: abdominal and gastric contraction, micturition reflex and breathing. IAP was measured, directly, via microsensor and, indirectly, by TM and intragastric manometry, in five different body positions. The study population consists in a population of 29 anatomical model, 14 males and 15 females, with an average weight of 12.04 ± 5.67 kilograms (Kg). The inclusion criteria consisted in the absence of abdominal disease that would. Principal Findings: IAP determination by direct method showed no differences in the five body positions (P=0.765). The indirect method with better correlation with the direct was TM (cc0.87). Indirect methods revealed statistically significant differences with the direct, only in the Trendelenburg and reverse Trendelenburg. Conclusions: The clinical impact of this study is to decrease the doubts in the measurements of IAP. This study improves the knowledge of the application of the direct and indirect methods to accesses IAP. IAP is not affected by body position and the direct pressure value measured in all positions is constant. Only if the indirect methods are used, in Trendelenburg and reverse Trendelenburg positions, they may underestimate or overestimate IAP value. For the first time it was explained why this phenomenon occurs

    Evaluating the relationship between ciprofloxacin prescription and non-susceptibility in Salmonella Typhi in Blantyre, Malawi: an observational study

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    Background Ciprofloxacin is the first-line drug for treating typhoid fever in many countries in Africa with a high disease burden, but the emergence of non-susceptibility poses a challenge to public health programmes. Through enhanced surveillance as part of vaccine evaluation, we investigated the occurrence and potential determinants of ciprofloxacin non-susceptibility in Blantyre, Malawi. Methods We conducted systematic surveillance of typhoid fever cases and antibiotic prescription in two health centres in Blantyre, Malawi, between Oct 1, 2016, and Oct 31, 2019, as part of the STRATAA and TyVAC studies. In addition, blood cultures were taken from eligible patients presenting at Queen Elizabeth Central Hospital, Blantyre, as part of routine diagnosis. Inclusion criteria were measured or reported fever, or clinical suspicion of sepsis. Microbiologically, we identified Salmonella enterica serotype Typhi (S Typhi) isolates with a ciprofloxacin non-susceptible phenotype from blood cultures, and used whole-genome sequencing to identify drug-resistance mutations and phylogenetic relationships. We constructed generalised linear regression models to investigate associations between the number of ciprofloxacin prescriptions given per month to study participants and the proportion of S Typhi isolates with quinolone resistance-determining region (QRDR) mutations in the following month. Findings From 46 989 blood cultures from Queen Elizabeth Central Hospital, 502 S Typhi isolates were obtained, 30 (6%) of which had either decreased ciprofloxacin susceptibility, or ciprofloxacin resistance. From 11 295 blood cultures from STRATAA and TyVAC studies, 241 microbiologically confirmed cases of typhoid fever were identified, and 198 isolates from 195 participants sequenced (mean age 12·8 years [SD 10·2], 53% female, 47% male). Between Oct 1, 2016, and Aug 31, 2019, of 177 typhoid fever cases confirmed by whole-genome sequencing, four (2%) were caused by S Typhi with QRDR mutations, compared with six (33%) of 18 cases between Sept 1 and Oct 31, 2019. This increase was associated with a preceding spike in ciprofloxacin prescriptions. Every additional prescription of ciprofloxacin given to study participants in the preceding month was associated with a 4·2% increase (95% CI 1·8–7·0) in the relative risk of isolating S Typhi with a QRDR mutation (p=0·0008). Phylogenetic analysis showed that S Typhi isolates with QRDR mutations from September and October, 2019, belonged to two distinct subclades encoding two different QRDR mutations, and were closely related (4–10 single-nucleotide polymorphisms) to susceptible S Typhi endemic to Blantyre. Interpretation We postulate a causal relationship between increased ciprofloxacin prescriptions and an increase in fluoroquinolone non-susceptibility in S Typhi. Decreasing ciprofloxacin use by improving typhoid diagnostics, and reducing typhoid fever cases through the use of an efficacious vaccine, could help to limit the emergence of resistance

    Avaliação do cumprimento da NR-18 em função do porte de obra residencial e proposta de lista de verificação da NR-18

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    O presente trabalho investiga as reais condições dos ambientes de trabalho da indústria da construção, tendo em vista os problemas relacionados à segurança do trabalho nos canteiros de obras. Formulou-se a hipótese de haver discrepância no grau de cumprimento da NR-18 em obras de diferentes portes (pequena, média e grande). Baseado em uma lista de verificação do grau de cumprimento dos requisitos da NR-18, foram avaliados 115 canteiros de obra na cidade de Chapecó - SC. Para cada item da lista de verificação foi atribuída uma nota e, após compilar as informações, estas foram avaliadas conforme os objetivos da pesquisa. Fez-se uma análise crítica para os cinco piores e os cinco melhores itens observados para as obras pequenas, médias e grandes. Analisando-se os resultados é possível afirmar que há uma diferença significativa de aplicação da NR-18 nos diferentes portes de obras, sendo que as obras de grande porte obtiveram uma média final (6,47) significativamente superior em relação às obras pequenas (1,97). Desta forma, foi corroborada a hipótese formulada, podendo se atribuir este resultado a diversos fatores, entre os quais a falta de habilidades gerenciais de segurança e saúde do trabalho nas pequenas empresas. Outra contribuição deste artigo foi a proposta de uma nova lista de verificação para avaliar o grau de cumprimento da NR-18 nos canteiros de obra

    Overview of cattle diseases listed under category C, D or E in the animal health law for wich control programmes are in place within Europe

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    13 páginas, 5 figuras, 3 tablas.The COST action “Standardising output-based surveillance to control non-regulated diseases of cattle in the European Union (SOUND control),” aims to harmonise the results of surveillance and control programmes (CPs) for non-EU regulated cattle diseases to facilitate safe trade and improve overall control of cattle infectious diseases. In this paper we aimed to provide an overview on the diversity of control for these diseases in Europe. A non-EU regulated cattle disease was defined as an infectious disease of cattle with no or limited control at EU level, which is not included in the European Union Animal health law Categories A or B under Commission Implementing Regulation (EU) 2020/2002. A CP was defined as surveillance and/or intervention strategies designed to lower the incidence, prevalence, mortality or prove freedom from a specific disease in a region or country. Passive surveillance, and active surveillance of breeding bulls under Council Directive 88/407/EEC were not considered as CPs. A questionnaire was designed to obtain country-specific information about CPs for each disease. Animal health experts from 33 European countries completed the questionnaire. Overall, there are 23 diseases for which a CP exists in one or more of the countries studied. The diseases for which CPs exist in the highest number of countries are enzootic bovine leukosis, bluetongue, infectious bovine rhinotracheitis, bovine viral diarrhoea and anthrax (CPs reported by between 16 and 31 countries). Every participating country has on average, 6 CPs (min–max: 1–13) in place. Most programmes are implemented at a national level (86%) and are applied to both dairy and non-dairy cattle (75%). Approximately one-third of the CPs are voluntary, and the funding structure is divided between government and private resources. Countries that have eradicated diseases like enzootic bovine leukosis, bluetongue, infectious bovine rhinotracheitis and bovine viral diarrhoea have implemented CPs for other diseases to further improve the health status of cattle in their country. The control of non-EU regulated cattle diseases is very heterogenous in Europe. Therefore, the standardising of the outputs of these programmes to enable comparison represents a challenge.Peer reviewe

    Evaluating the relationship between ciprofloxacin prescription and non-susceptibility in Salmonella Typhi in Blantyre, Malawi: an observational study

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    Background Ciprofloxacin is the first-line drug for treating typhoid fever in many countries in Africa with a high disease burden, but the emergence of non-susceptibility poses a challenge to public health programmes. Through enhanced surveillance as part of vaccine evaluation, we investigated the occurrence and potential determinants of ciprofloxacin non-susceptibility in Blantyre, Malawi. Methods We conducted systematic surveillance of typhoid fever cases and antibiotic prescription in two health centres in Blantyre, Malawi, between Oct 1, 2016, and Oct 31, 2019, as part of the STRATAA and TyVAC studies. In addition, blood cultures were taken from eligible patients presenting at Queen Elizabeth Central Hospital, Blantyre, as part of routine diagnosis. Inclusion criteria were measured or reported fever, or clinical suspicion of sepsis. Microbiologically, we identified Salmonella enterica serotype Typhi (S Typhi) isolates with a ciprofloxacin non-susceptible phenotype from blood cultures, and used whole-genome sequencing to identify drug-resistance mutations and phylogenetic relationships. We constructed generalised linear regression models to investigate associations between the number of ciprofloxacin prescriptions given per month to study participants and the proportion of S Typhi isolates with quinolone resistance-determining region (QRDR) mutations in the following month. Findings From 46 989 blood cultures from Queen Elizabeth Central Hospital, 502 S Typhi isolates were obtained, 30 (6%) of which had either decreased ciprofloxacin susceptibility, or ciprofloxacin resistance. From 11 295 blood cultures from STRATAA and TyVAC studies, 241 microbiologically confirmed cases of typhoid fever were identified, and 198 isolates from 195 participants sequenced (mean age 12·8 years [SD 10·2], 53% female, 47% male). Between Oct 1, 2016, and Aug 31, 2019, of 177 typhoid fever cases confirmed by whole-genome sequencing, four (2%) were caused by S Typhi with QRDR mutations, compared with six (33%) of 18 cases between Sept 1 and Oct 31, 2019. This increase was associated with a preceding spike in ciprofloxacin prescriptions. Every additional prescription of ciprofloxacin given to study participants in the preceding month was associated with a 4·2% increase (95% CI 1·8–7·0) in the relative risk of isolating S Typhi with a QRDR mutation (p=0·0008). Phylogenetic analysis showed that S Typhi isolates with QRDR mutations from September and October, 2019, belonged to two distinct subclades encoding two different QRDR mutations, and were closely related (4–10 single-nucleotide polymorphisms) to susceptible S Typhi endemic to Blantyre. Interpretation We postulate a causal relationship between increased ciprofloxacin prescriptions and an increase in fluoroquinolone non-susceptibility in S Typhi. Decreasing ciprofloxacin use by improving typhoid diagnostics, and reducing typhoid fever cases through the use of an efficacious vaccine, could help to limit the emergence of resistance

    Non-Invasive System for Measuring Intra-Abdominal Pressure

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    Extended Abstract Purpose: Monitoring surgical and intensive care patients is an usual procedure in hospital units Methods: The selection of the features was realized according with the literature review of the parameters that can be influenced by IAP Results The IAP showed average results of 4.05 ± 3.60 mmHg and the parameters with the highest statistical correlation with the IAP were: weight (cc0.48), ACSA (cc0.46), perimeter (cc0.34), diastolic (cc0.25) and mean blood pressure (cc0.17), duration of the QRS (cc0.20) and the amplitude of the R wave (cc0.12). Systems based on the 18 inputs were constructed and a simplified system was created only with the inputs with the highest correlation with the output. The best ANN created was built with 7 inputs, with the activation function Tansig and the training function Bayseian regularization. This network showed results of linear regression coefficient of 0.97. The ANFIS that demonstrated the best results was also constructed with the simplified model, with only 7 entries. The best results were obtained with Sugeno inference system and 20 rules demonstrating an error of 2.10 (training), 1.73 (test) and 3.79 (validation). Conclusion: This type of non-invasive methodology allows the determination of IAP continuously. The ANN and the ANFIS created allowed predicting IAP with low error compared to real values. This type of methodology can be used in human medicine

    Test rig for micro gear and experimental analysis on the meshing condition and failure characteristics of steel micro involute gear and metallic glass one

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    A test rig to evaluate the performance of a micro involute gear with a diameter below 1 mm has been developed. Shaft position and shaft center distance of gears have great influence on the gear performance and therefore they must be adjusted precisely. In this research, the measurement and adjustment method of gear assembly condition and an in-situ observation system of gear condition are proposed, that are appropriately designed for micro gears. The meshing condition of micro involute gears is investigated experimentally. Based on the observation of sliding marks on the tooth flank, it is clarified that the meshing condition of a micro involute gear follows the meshing theory of an involute gear. Failure modes of SK4 micro gears and metallic glass micro gears are investigated. The experimental results indicated that SK4 micro gears suffer severe wear under unlubricated conditions that generate powderlike wear particles. On the other hand, flakelike wear particles appear in the metallic glass micro gear. (C) 2010 Elsevier Ltd. All rights reserved
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