283 research outputs found
In-situ biosynthesis of bacterial cellulose - Porto Santo clay composites: application in drug delivery
Bacterial cellulose/clay composites have been lately receiving attention by the
scientific community towards drug delivery systems and wound dressing applications.
The current work aims to determine the most suitable culture conditions to obtain an
effective drug delivery membrane through an environmentally-friendly method. Thus,
the BCC composites were synthesized by BC-producing bacteria, Gluconacetobacter sp.,
using an in-situ biosynthesis method. Gluconacetobacter sp. produced 2.95 g/L BC at
optimized culture conditions of 2% glucose, pH of 3.25 and 7 days of cultivation. To
obtain the different BCC composites, an agitated culture method was employed. The
results show that the introduction of PS clay onto BC obstructed the pores of the
synthetized composites, which led into a less porous and more compact material. Additionally, an increase in ϒsd (79%), surface basicity (Kb/Ka → 4.2) and thermal stability
(83%) of BC was observed. The composites with incorporated 2% neomycin sulphate
were evaluated in terms of their drug release ability and antibacterial activities. These
materials exhibited a sustained release up to 24h in a PBS buffer with pH 7.4, whereby
they could be used as capsules for oral administration, in the treatment of ileum
infections. Furthermore, BCC composites with incorporated neomycin sulphate could be
applied as clinical wound healing materials due to their strong antibacterial activities
against Staphylococcus aureus and Escherichia coli.Os compósitos de celulose bacteriana/argila têm recebido uma grande atenção
por parte da comunidade científica para o desenvolvimento de sistemas de libertação
controlada de fármacos e aplicação de curativos. Este trabalho visa determinar as
condições ideais do meio de cultura para produção de CB, de forma a obter um sistema
de entrega de fármacos eficaz através de um método amigo do ambiente. Assim, foram
sintetizados compósitos de CB/argila do Porto Santo por bactérias produtoras de CB,
Gluconacetobacter sp., através da utilização do método de biossíntese in-situ. A bactéria
Gluconacetobacter sp. produziu 2,95 g/L de CB em condições ótimas de 2% de glucose,
em um pH de 3,25 e 7 dias de cultivo. Para obter os diferentes compósitos, foi
implementada uma cultura em agitação. A introdução de argilas na CB obstruiu os poros
dos compósitos sintetizados, o que levou à obtenção de um material menos poroso e mais compacto. Para além disso, foi observado um aumento do ϒsd (79%), basicidade da
superfície (Kb/Ka → 4.2) e estabilidade térmica (83%) da CB. Os compósitos com 2% de
sulfato de neomicina incorporada, foram estudados de forma a avaliar a capacidade de
libertação de fármaco e respetiva atividade antibacteriana. Estes materiais
apresentaram uma libertação controlada do fármaco durante 24h em tampão PBS com
pH 7,4, pelo que poderão ser utilizados como cápsulas para administração oral, no
tratamento de infeções do íleo. Além disso, a utilização de compósitos de CB/argila do
Porto Santo com sulfato de neomicina incorporado poderão ser aplicados na
cicatrização de feridas devido à sua atividade antibacteriana contra a Staphylococcus
aureus e Escherichia coli
Estudo e definição de critérios gerais de alerta e de alarme para muros de suporte e taludes rodoviários na sua fase de exploração. Casos de estudo
A dissertação tem como objetivo principal o estudo e a definição de critérios gerais de alerta e de alarme para a aplicação em estruturas geotécnicas de suporte de terras e em taludes rodoviários durante a fase de exploração. Este estudo advém do facto de estes critérios não se encontrarem definidos, na fase de projeto, nos planos de observação e auscultação para um conjunto amplo de estruturas instrumentadas no grupo de Concessões e Subconcessões da Ascendi I.G.I. No conjunto de estruturas analisadas destacam-se as seguintes tipologias: I) Muros ancorados, II) Muros de betão armado, III) Muros de terra armada, IV) Muros de gabiões, V) Taludes de aterro e VI) Taludes de escavação. Na primeira parte são apresentadas as principais causas e consequências da instabilização de taludes, referindo-se também ações de manutenção e/ou conservação que podem ser adotadas para mitigar as ações sobre os taludes e retardar a probabilidade de ocorrências de patologias que possam originar situações de instabilização das estruturas. Ainda nesta secção são apresentados os principais métodos de monitorização e de instrumentação que se encontram disponíveis para observação e auscultação de estruturas geotécnicas. Na segunda parte do trabalho são apresentados os níveis gerais de alerta e de alarme definidos e avaliados, com o objetivo de serem aplicados no conjunto de estruturas instrumentadas, mas que se encontram sem um plano de observação e auscultação completo. De seguida, são apresentados os muros e taludes que foram alvo do estudo realizado e para os quais os critérios propostos serão aplicados com o objetivo de analisar e avaliar o seu comportamento ao longo da fase de exploração. No último capítulo são apresentadas as conclusões finais do trabalho desenvolvido e apresentado um conjunto de perspetivas futuras que têm como objetivo consolidar os níveis propostos.The dissertation has as main goal the study and the definition of general alert and alarm levels for the application in geotechnical structures from earth retaining walls and road slopes during its exploitation stage. This study accrues from the non-definition of these levels by the observation and auscultation plans of a wide range of instrumented structures in the group of concession and sub-concession from Ascendi I.G.I. In the set of structures, the following typologies stand out: anchored walls, reinforced concrete walls, reinforced earth walls, gabion walls, embankment slopes and excavation slopes. In the first part, the main causes and consequences of instability of slopes are presented, also referring the solution that can be adopted to mitigate the actions that act on the slope and in this way reduce the probability of them reaching instability situations. Also, in this section, the main monitoring and instrumentation methods that are available for observation and auscultation of geotechnical structures are presented. In the second part of the present work, the general alert and alarm levels are presented, with the objective of being implemented to the set of structures that have instruments but do not present a complete observation and auscultation plan. In the next chapter, the walls and slopes that were the target of the study are presented and for which the proposed levels will be applied in order to analyze and evaluate their behavior over their exploitation stage. In the last chapter, the final remarks of the work developed are made and an outlook are presented with the aim of strengthening the proposed levels
NUMBERS OF MORTALITY IN THE STATE OF MARANHÃO, BRAZIL
Death is defined by the World Health Organization as the cessation of vital signs at any time after birth, with no possibility of resuscitation. The objective of this study was to analyze the temporal dynamics of mortality in the State of Maranhão using data from the Mortality Information System (SIM) of the National Department of Health. For this, it was used information on the mortality rate of all municipalities in the State in the years 2000, 2010 and 2014. Data were initially analyzed through descriptive statistics to determine the main statistical moments. The statistical analysis demonstrated that data presented high coefficient of variation value and did not show normal frequency distribution. Through the maps generated it is possible to verify that only the city of São Luís had more than 1000 deaths in the three years analyzed. In addition to the growth in the total number of deaths in the state, accompanying the population increase
Pollen Analysis of Food Pots Stored by Melipona subnitida Ducke (Hymenoptera: Apidae) in a Restinga area
The geographic distribution of Melipona subnitida covers the dry areas in the northeastern Brazil, where it plays an important role as pollinator of many wild plant species. In the current study, the botanical species this bee uses as pollen and nectar sources in a restinga area of the Maranhão State, Brazil, were identified by analyzing pollen grains present in their storage pots in the nests. Samples were collected from five colonies bimonthly, from April 2010 to February 2011. In all the samples, 58 pollen types were identified; the families Fabaceae (8) and Myrtaceae (5) had the largest number of pollen types. In the pollen pots, 52 pollen types were identified; Fabaceae, Melastomataceae, Myrtaceae and Dilleniaceae species were dominant. In honey samples, 50 pollen types were found, with a predominance of nectariferous and polliniferous plant species. Out of the total of pollen types from nectariferous plants identified in honey, 20 pollen types contributed to the honey composition. Humiria balsamifera occurred in high frequency and was predominant in October. Chrysobalanus icaco, Coccoloba sp., Cuphea tenella and Borreria verticillata were also important for honey composition. The occurrence of a high number of minor pollen types indicated that M. subnitida visits many species in the locality; however, it was possible to observe that its floral preferences are very similar to those from other Melipona species
Bleb morphology of glaucoma drainage devices on magnetic resonance imaging
© 2023 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Purpose: To evaluate bleb morphology features of different glaucoma drainage devices (GDD) using magnetic resonance imaging (MRI).
Materials and methods: Prospective cohort study of GDD and bleb morphology in consecutive glaucoma patients implanted with Ahmed Glaucoma Valve (AGV), Paul Glaucoma Implant (PGI), Baerveldt Glaucoma Implant (BGI) and Ahmed ClearPath (ACP) devices. Thirty-six eyes from 30 consecutive patients underwent standardized GDD implantation followed by MRI at least 1 month after surgery. Main outcomes included bleb volume and endplate position relative to the optic nerve. Secondary outcomes included intraocular pressure (IOP), medication and surgical complications during a 12-month follow-up.
Results: Seven eyes were implanted with the AGV (19%), 5 with BGI (14%), 16 with PGI (44%) and 8 with ACP (22%). MRI scans were obtained 85 ± 66 days after surgery. Mean total bleb volume was 563 ± 390 mm3 . This bleb volume was inversely correlated with early post-operative IOP (day 7; rs = -0.3326, p = 0.0475) but positively correlated with IOP at 12 months (rs = 0.3592, p = 0.0341). No significant difference in total bleb volume was found between GDD types (p = 0.1223). A double-layered bleb was observed in 34 eyes (94%). The inferior bleb volume was significantly larger in PGI devices versus other GDD types (380 ± 205 vs. 193 ± 161 mm3 ; p = 0.0043). Distance from the endplate to the optic nerve was 9.5 ± 4.0 mm, similar across GDDs (p = 0.2519).
Conclusions: Double-layered blebs are a common finding with GDDs. Bleb volume showed different correlations with IOP at distinct timepoints and the PGI device formed larger blebs. A standardized GDD implantation technique ensures a safe distance from the GDD endplate to the optic nerve.info:eu-repo/semantics/publishedVersio
Pollen Analysis of the Post-Emergence Residue of Euglossa Bees (Apidae: Euglossini) Nesting in an Urban Fragment
Euglossini bees are considered pollinators of a wide variety of plants in the Neotropical region, but little is known about their floral preferences. In this study, we identified the botanical species used as pollen and nectar sources by three Euglossa species (Euglossa cordata, Euglossa townsendi, and Euglossa securigera) using pollen residue found in brood cells from trap nests installed in an urban fragment in São Luís, Maranhão, Brazil. In 14 analyzed Eg. cordata nests, 23 pollen types were observed, in 7 Eg. townsendi nests, 10 pollen types were observed, and in 1 nest of Eg. securigera, 6 morph types were identified. Solanum (Solanaceae), Zanthoxylum (Rutaceae), Mimosa pudica (Fabaceae), and Chamaecrista (Fabaceae) pollen types were common to all three bee species. Principal components analysis showed 83.04% variability on the first two axes, demonstrating substantial similarity among the samples. Solanum, Mimosa pudica, and Zanthoxylum were the principal components in the ranking. Larger diversity values (mean = 0.80) in some samples indicate that the species gathered resources in a heterogeneous manner; this resembles the findings of other studies of Euglossa. In general, the bees exhibited overlapping niches with regard to the most abundant pollens in the nests, but the females showed individual plasticity when gathering the floral resources
Learning from the covid-19 outbreaks in long-term care facilities: a systematic review
© The Author(s) 2023. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background: The COVID-19 pandemic has devastatingly affected Long-Term Care Facilities (LTCF), exposing aging people, staff members, and visitors. The world has learned through the pandemic and lessons can be taken to adopt effective measures to deal with COVID-19 outbreaks in LTCF. We aimed to systematically review the available evidence on the effect of measures to minimize the risk of transmission of COVID-19 in LTCs during outbreaks since 2021.
Methods: The search method was guided by the preferred reporting items for systematic reviews (PRISMA) and the reporting guideline synthesis without meta-analysis (SWiM) in systematic reviews. The search was performed in April 2023. Observational and interventional studies from the databases of PubMed, Web of Science, Scopus, Cochrane Systematic Reviews, CINAHL, and Academic Search were systematically reviewed. We included studies conducted in the LTCF with outbreaks that quantitatively assess the effect of non-pharmacological measures on cases of COVID-19. Two review authors independently reviewed titles for inclusion, extracted data, and undertook the risk of bias according to pre-specified criteria. The quality of studies was analyzed using the Joanna Briggs Institute Critical Appraisal.
Results: Thirteen studies were included, with 8442 LTCF experiencing COVID-19 outbreaks and 598 thousand participants (residents and staff members). Prevention and control of COVID-19 infection interventions were grouped into three themes: strategic, tactical, and operational measures. The strategic measures reveal the importance of COVID-19 prevention and control as LTCF structural characteristics, namely the LTCF size, new admissions, infection control surveillance, and architectural structure. At the tactical level, the lack of personal and long staff shifts is related to COVID-19's spread. Operational measures with a favorable effect on preventing COVID-19 transmission are sufficient. Personal protective equipment stock, correct mask use, signaling, social distancing, and resident cohorting.
Conclusions: Operational, tactical, and strategic approaches may have a favorable effect on preventing the spread of COVID-19 in LTCFs experiencing outbreaks. Given the heterogeneous nature of the measures, performing a meta-analysis was not possible. Future research should use more robust study designs to explore similar infection control measures in LTCFs during endemic situations with comparable outbreaks.
Trial registration: The protocol of this systematic review was registered in PROSPERO (CRD42020214566).info:eu-repo/semantics/publishedVersio
Foraging distance of Melipona subnitida Ducke (Hymenoptera: Apidae)
The current study aimed at estimating the maximum foraging distance of the stingless bee Melipona subnitida by comparing the efficacy of two methods: training of workers with an artificial feeding source and the capture-recapture technique, which consisted at marking bees that were released at different distances from the nest, after which the number of bees that returned to the colony was recorded. Under the training method, the mean foraging distance of the three colonies studied was 1,120 m and maximum foraging distance of 1,160 m. Yet the number of recruits and reactivated foragers for each colony were quantified, the average maximum distance unil recruitment occurred was 886,66 m. In the capture-recapture method, the maximum flight distance of captured foragers ranged from 3,600 to 4,000 m, which was 2,700 m farther than the maximum flight distance recorded using the artificial feeding method. Therefore, we verified that M. subnitida is a species that can travel long distances in search for food. Our results also suggest that an abundance of resources near the nest can reduce its foraging area
Usage patterns of oral H1-antihistamines in 10 European countries:A study using MASK-air® and Google Trends real-world data
Real-world data represent an increasingly important source of knowledge in health care. However, assessing their representativeness can be challenging. We compared (i) real-world data from a mobile app for allergic rhinitis (MASK-air®) on the usage of oral H1-antihistamines from 2016 to 2020 in 10 European countries with (ii) Google Trends data on the relative volume of searches for such antihistamines. For each country, we sorted 5 different oral H1-antihistamines by their frequency of use and volume of searches. We found perfect agreement on the order of antihistamine use in MASK-air® and in Google Trends searches in 4 countries (France, Germany, Sweden, and the United Kingdom). Different levels of agreement were observed in the remaining countries (kappa coefficient from -0.50 to 0.75). Oral H1-antihistamine data from Google Trends and MASK-air® were consistent with nationwide medication sales data from France, Germany, and the United Kingdom. These results suggest that MASK-air® data may be consistent with other sources of real-world data, although assessing the representativeness of their users may require further studies
Absence of Tau triggers age-dependent sciatic nerve morphofunctional deficits and motor impairment
Dementia is the cardinal feature of Alzheimer's disease (AD), yet the clinical symptoms of this disorder also include a marked loss of motor function. Tau abnormal hyperphosphorylation and malfunction are well-established key events in AD neuropathology but the impact of the loss of normal Tau function in neuronal degeneration and subsequent behavioral deficits is still debated. While Tau reduction has been increasingly suggested as therapeutic strategy against neurodegeneration, particularly in AD, there is controversial evidence about whether loss of Tau progressively impacts on motor function arguing about damage of CNS motor components. Using a variety of motor-related tests, we herein provide evidence of an age-dependent motor impairment in Tau-/- animals that is accompanied by ultrastructural and functional impairments of the efferent fibers that convey motor-related information. Specifically, we show that the sciatic nerve of old (17-22-months) Tau-/- mice displays increased degenerating myelinated fibers and diminished conduction properties, as compared to age-matched wild-type (Tau+/+) littermates and younger (4-6months) Tau-/- and Tau+/+ mice. In addition, the sciatic nerves of Tau-/- mice exhibit a progressive hypomyelination (assessed by g-ratio) specifically affecting large-diameter, motor-related axons in old animals. These findings suggest that loss of Tau protein may progressively impact on peripheral motor system.The work was supported by grants 'PTDC/SAU-NMC/113934/2009,' 'PTDC/SAU-NSC/118194/2010,' 'SFRH/BPD/97281/2013,' PTDC/SAU-NSC/118194/2010,' 'SFRH/BPD/80118/2011,' 'SFRH/BD/89714/2012' funded by FCT-Portuguese Foundation for Science and Technology and project DoIT-Desenvolvimento e Operacionalizacao da Investigacao de Translacao (No do projeto 13853), funded by Fundo Europeu de Desenvolvimento Regional (FEDER) throughout the Programa Operacional Fatores de Competitividade (POFC). In addition, this work was also co-financed by European Union FP7 project SwitchBox (NS) and the Portuguese North Regional Operational Program (ON.2 - O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER).info:eu-repo/semantics/publishedVersio
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