Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.009
Filtrar
1.
Sci Total Environ ; : 173548, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38830418

RESUMO

Coastal dunes result from complex interactions between sand transport, topography and vegetation. However, uncertainty still persists due to limited quantitative analyses, integrating plant distribution and morphologic changes. This study aims to assess the initiation and maintenance of feedback processes by analysing the early development stages of incipient foredunes, combining data on the evolution of the plant cover and communities and dune morphology. Over three years, the monitoring of a newly formed dune (1 ha plot) reveals the progressive plant colonisation and the episodic accumulation of sand around vegetated areas controlled by sediment availability. Distinct colonisation rates were observed, influenced by inherited marine conditions, namely topography and presence of beach wrack. Berm-ridges provided elevations above the critical threshold for plant colonisation and surface roughness, aiding sediment accumulation. Beach wrack above this threshold led to rapid expansion and higher plant concentration. In the initial stages, vegetation cover significantly influenced sediment accumulation patterns, with higher accumulation around areas with high plant cover and low slopes or around areas with sparse vegetation but milder slopes. As the dune system matured and complexity grew, the link between vegetation cover and accumulation became nonlinear. Mid to low coverages (5-30 %) retained most of the observed accumulation, especially when coupled with steep slopes, resulting from positive feedbacks between vegetation, topography and sand transport. As foredune developed, vegetation cover and diversity increased while inherited morphologies grew vertically, explaining the emergence of dune ridge morphological types. Flat surfaces lacking wrack materials experienced a three-year delay in colonisation and sand accumulation, leading to the formation of terrace-type incipient foredunes. These observations underline feedback processes during the early stages of dune formation, with physical feedbacks primarily driving initiation and biophysical feedbacks prevailing in subsequent colonisation stages.

2.
Heliyon ; 10(9): e29781, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38698978

RESUMO

Supermarkets are significant consumers of electricity and contribute to the generation of associated pollutant emissions. This will help to mitigate the impact of increased energy costs on the prices of products sold in supermarkets. Therefore, it is essential to reduce energy consumption, starting with the equipment that consumes the most electricity, such as refrigeration, and using the residual thermal energy generated in supermarkets. This paper discusses the impact of rising energy costs in the post-Covid era and during the energy crisis. It evaluates the environmental and energy benefits of implementing energy improvements and utilizing residual energy in real supermarkets. The analysis takes into account the socio-economic characteristics of the EU-27 countries, which affect the economic feasibility of these measures. This would prevent the release of 122 tons of CO2 per year for each supermarket, resulting in energy savings of around 70 % or 305 kWh/m2. The required investments would have a payback period of 4 years.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38740375

RESUMO

INTRODUCTION: We previously showed that a 3-week oral Metformin (MET) treatment enhances the osteogenic potential of bone marrow stromal cells (BMSCs) and improves several bone histomorphometric parameters in Wistar rats with metabolic syndrome (MetS). However, the skeletal effects of extended periods of MET are still not completely elucidated. Hence, we investigated the impact of a prolonged (3-month) MET treatment on bone architecture, histomorphometric and biomechanics variables and osteogenic potential of BMSCs in Wistar rats with or without MetS. MATERIALS AND METHODS: 36 young male Wistar rats were randomized into four groups (n=9) that received either 20% fructose (F); MET (MET); F plus MET treatments (FMET); or drinking water alone (Veh). Rats were euthanized, blood was collected, and bones were dissected and processed for pQCT analysis, static and dynamic histomorphometry and bone biomechanics. In addition, BMSCs were isolated to determine their osteogenic potential. RESULTS: MET affected trabecular and cortical bone, altering bone architecture and biomechanics. Furthermore, MET increased the pro-resorptive profile of BMSCs. In addition, fructose-induced MetS practically did not affect the skeleton's structural or mechanical variables. CONCLUSION: A 3-month treatment with MET (with or without MetS) affects bone architecture and biomechanical variables in Wistar rats.

6.
Mol Ther ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38796707

RESUMO

Lafora disease is a rare and fatal form of progressive myoclonic epilepsy typically occurring early in adolescence. The disease results from mutations in the EPM2A gene, encoding laforin, or the EPM2B gene, encoding malin. Laforin and malin work together in a complex to control glycogen synthesis and prevent the toxicity produced by misfolded proteins via the ubiquitin-proteasome system. Disruptions in either protein cause alterations in this complex, leading to the formation of Lafora bodies containing abnormal, insoluble, and hyperphosphorylated forms of glycogen. We used the Epm2a-/- knock-out mouse model of Lafora disease to apply gene therapy by administering intracerebroventricular injections of a recombinant adeno-associated virus carrying the human EPM2A gene. We evaluated the effects of this treatment through neuropathological studies, behavioral tests, video-electroencephalography, electrophysiological recordings, and proteomic/phosphoproteomic analysis. Gene therapy ameliorated neurological and histopathological alterations, reduced epileptic activity and neuronal hyperexcitability, and decreased the formation of Lafora bodies. Moreover, differential quantitative proteomics and phosphoproteomics revealed beneficial changes in various molecular pathways altered in Lafora disease. Our results represent proof-of-principle for gene therapy with the coding region of the human EPM2A gene as a treatment for EPM2A related Lafora disease.

7.
Transpl Immunol ; 84: 102055, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38744349

RESUMO

Respiratory complications following allogeneic HSCT can lead to severe morbidity and mortality. Lung transplantation (LT) is a potential treatment for select patients with late-onset non-infectious pulmonary complications post-HSCT. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive biomarker for monitoring the health of allografts following LT. However, its utility in a multi-genome setting of LT after HSCT has not yet been clinically validated. Here we describe a case of a 75-year-old, male patient who underwent single-lung transplantation for BOS related to chronic GVHD and presented with persistently elevated dd-cfDNA levels. In a surveillance biopsy, the patient was diagnosed with mild acute cellular rejection at three months. The patient's lung function remained stable, and the reported dd-cfDNA levels decreased after the rejection episode but remained elevated above levels that would be considered quiescent for LT alone. In this unique setting, as 3 different genomes contributed to the dd-cfDNA% reported value, valuable insight was obtained by performing further analysis to separate the specific SNPs to identify the contribution of recipient, lung-donor, and HSCT-donor cfDNA. This study highlights the potential utility of dd-cfDNA in the multi-genome setting of lung transplant post-HSCT, nuances that need to be considered while interpreting the results, and its value in monitoring lung rejection.


Assuntos
Ácidos Nucleicos Livres , Transplante de Células-Tronco Hematopoéticas , Transplante de Pulmão , Doadores de Tecidos , Humanos , Masculino , Ácidos Nucleicos Livres/sangue , Idoso , Rejeição de Enxerto/diagnóstico , Doença Enxerto-Hospedeiro/diagnóstico , Transplante Homólogo , Biomarcadores/sangue , Bronquiolite Obliterante/diagnóstico , Bronquiolite Obliterante/etiologia , Polimorfismo de Nucleotídeo Único
8.
Med Vet Entomol ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38741222

RESUMO

Alpha-Gal/α-Gal is an oligosaccharide produced by non-primate mammals. Humans have developed an immune response mediated by anti-α-Gal antibodies that can trigger an allergic reaction and cause anaphylaxis. In recent years, cases of patients with delayed allergic reaction to mammalian meat have been reported worldwide. In Spain, these cases have been related to the species Ixodes ricinus L. (Ixodida: Ixodidae), whose distribution is located in the north of the country. In this work, the presence of α-Gal in water-soluble extracts from samples of salivary glands and digestive tracts of Hyalomma lusitanicum Koch (Ixodida: Ixodidae) both engorged and collected from vegetation were studied. The presence of that epitope was confirmed by the presence of reactive proteins of >250 kDa in both samples. The highest concentrations of α-Gal were detected in salivary glands. Neither sex nor diet influenced the concentration of α-Gal, which seems to indicate its endogenous production and its possible inoculation to the host during tick feeding.

9.
Healthcare (Basel) ; 12(7)2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38610181

RESUMO

BACKGROUND: Dating violence has become a problem of social relevance with short- and long-term health consequences. Nurses are in a privileged position to detect and address this problem in health facilities and as school nurses in schools, providing health education and detecting this violence correctly. AIM: The aim of this study was to evaluate the cross-cultural validation of the Portuguese version of the Multidimensional Scale of Dating Violence-Short (MSDV 2.0). METHODS: A validation investigation was carried out in two phases: (1) cross-cultural adaptation of the items and content validation of the Portuguese version of MSDV 2.0 and (2) psychometric validation. RESULTS: Phase (1): The items of the original version include a cross-cultural translation from Spanish to Portuguese and analysed by a group of experts in gender violence and by the authors of the original scale, then a back translation was made and again reviewed by the experts. Young university students also participated for face validity, and a pilot test was carried out. Phase (2): Confirmatory factor analysis was performed using the robust maximum-likelihood estimation method, which confirmed the five-dimensional structure, obtaining good fit rates (chi-square significance (χ2) = 187.860 (p < 0.0001); root mean square error of approximation (RMSEA) = 0.049; comparative fit index (CFI) = 0.937; Tucker-Lewis index (TLI) = 0.923). Reliability analysis indicated adequate internal consistency (Cronbach's alpha (α) = 0.88 to 0.70). Finally, scores of the Portuguese versions MSDV 2.0 were correlated, as expected, positively with the Depression, Anxiety, and Stress Scale (DASS-21) (r = 0.36 to 0.16) and negatively with the Medical Outcomes Study Questionnaire Short Form 36, Health Survey (SF-36) (r = -0.30 to -0.14). CONCLUSIONS: To date, it is the only instrument that measures dating violence in a multidimensional way validated in the Portuguese university context.

10.
Parasitol Res ; 123(4): 196, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662084

RESUMO

Many pathogens are related to carcinogenesis. Chronic inflammation, as a result of persistent infection, leads to DNA damage, higher expression of oncogenes, decreased apoptosis and immunosuppression, which are some of the reasons for cancer induction. Among parasites, Schistosoma, Opistorchis and Clonorchis are recognised as infectious agents which contribute to cancer. A relationship between Anisakis and cancer was hypothesised because cellular responses to Anisakis products could result in inflammation and DNA damage. Previous research has shown a decrease in CD8+ γδ T-cells and an increase in αß and γδ T-cell apoptosis in colon cancer (CC) samples. Ninety-two CC patients and 60 healthy subjects were recruited. γδ and αß T-cells were analysed, and their apoptosis was evaluated. Anti-Anisakis antibodies were tested in sera from CC patients and controls. Anti-Anisakis IgG, IgM, IgA and IgE antibodies were significantly higher in CC patients. A significant increase in anti-Anisakis IgA levels was observed in patients with angiolymphatic invasion. The number of all γδ T-cells, as well as CD3+ CD4+ αß T-cells, was significantly lower in CC patients. The apoptosis of all T-cells was significantly increased in patients with CC. We observed a significantly higher percentage of anti-Anisakis IgE positive patients having a deficit of CD3+ γδ T-cells. Our results suggest a relationship between Anisakis and CC.


Assuntos
Anisakis , Anticorpos Anti-Helmínticos , Neoplasias do Colo , Humanos , Masculino , Pessoa de Meia-Idade , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Feminino , Neoplasias do Colo/imunologia , Neoplasias do Colo/parasitologia , Idoso , Animais , Anisakis/imunologia , Adulto , Apoptose , Idoso de 80 Anos ou mais , Subpopulações de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia
11.
Waste Manag ; 181: 101-113, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38603994

RESUMO

Significant quantities of Posidonia oceanica deposit on some beaches and coastlines every year, which generates high costs associated with the disposal of this waste. Pyrolysis may be an adequate way for its valorization. However, it would imply to know how the process takes place and if the removal of its natural detrital inorganic matter (epiphytes, marine salt and sand) is necessary, which are the objectives of this research. Pyrolysis by thermogravimetry-mass spectrometry was carried out on both the washed and unwashed samples. During this waste pyrolysis, the following occurs: (i) the high alkali metal chloride content promotes fragmentation reactions of carbohydrates and O formation, which increases HCOOH intensities at temperatures between 250 and 360 °C; (ii) from 500 °C to 650 °C, Fe2O3 and decomposition of carbonates seem to be involved in reactions that produce O release and steam and CO2 reforming of hydrocarbons and oxygenated organic compounds with H2 generation; (iii) from 650 °C to 750 °C, Fe2O3, high alkali metal content and carbonate decomposition generate char gasification, an increase in O release, SO2 capture and HCOOH formation. In general, the abundance of inorganic matter (chlorides, carbonates, etc.) minimizes the release of various compounds during pyrolysis, including SO2 and HCl, while increasing HCOOH production. Thus, this high content of inorganic matter may represent an advantage for its pyrolysis, producing value-added chemical products with a reduced environmental impact. Therefore, this study may be the starting point for defining the optimal pyrolysis conditions for this waste valorisation.


Assuntos
Alismatales , Pirólise , Dióxido de Enxofre , Alismatales/química , Dióxido de Enxofre/química , Ácido Clorídrico/química , Termogravimetria , Oxigênio/química
12.
J Therm Biol ; 121: 103854, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38657317

RESUMO

Amphibian diversity is most prominent in the warm and humid tropical and subtropical regions across the globe. Nonetheless, amphibians also inhabit high-altitude tropical mountains and regions at medium and high latitudes, exposing them to subzero temperatures and requiring behavioural or physiological adaptations to endure freezing events. While freeze tolerance has been predominantly reported in high-latitude zones where species endure prolonged freezing (several weeks or months), less is known about mid-latitudes amphibians exposed to occasional subzero temperatures. In this study, we employed a controlled ecological protocol, subjecting three frog species from the Iberian Peninsula (Rana parvipalmata, Epidalea calamita, and Pelobates cultripes) to a 2-h exposure to temperatures of -2 °C to investigate the accumulation of urea and glucose as physiological mechanisms associated with survival at freezing temperatures. Our results revealed a moderate response in the production of cryoprotectant metabolites under experimental freezing conditions, particularly urea, with notable findings in R. parvipalmata and E. calamita and no response in P. cultripes. However, no significant alterations in glucose concentrations were observed in any of the studied frog species. This relatively weak freezing tolerance response differs from the strong response exhibited by amphibians inhabiting high latitudes and enduring prolonged freezing conditions, suggesting potential reliance on behavioural adaptations to cope with occasional freezing episodes.


Assuntos
Anuros , Congelamento , Glucose , Ureia , Animais , Anuros/fisiologia , Anuros/metabolismo , Ureia/metabolismo , Glucose/metabolismo , Aclimatação , Ranidae/fisiologia , Clima
13.
EBioMedicine ; 103: 105096, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38574408

RESUMO

BACKGROUND: Type 2 diabetes (T2D) susceptibility is influenced by genetic and environmental factors. Previous findings suggest DNA methylation as a potential mechanism in T2D pathogenesis and progression. METHODS: We profiled DNA methylation in 248 blood samples from participants of European ancestry from 7 twin cohorts using a methylation sequencing platform targeting regulatory genomic regions encompassing 2,048,698 CpG sites. FINDINGS: We find and replicate 3 previously unreported T2D differentially methylated CpG positions (T2D-DMPs) at FDR 5% in RGL3, NGB and OTX2, and 20 signals at FDR 25%, of which 14 replicated. Integrating genetic variation and T2D-discordant monozygotic twin analyses, we identify both genetic-based and genetic-independent T2D-DMPs. The signals annotate to genes with established GWAS and EWAS links to T2D and its complications, including blood pressure (RGL3) and eye disease (OTX2). INTERPRETATION: The results help to improve our understanding of T2D disease pathogenesis and progression and may provide biomarkers for its complications. FUNDING: Funding acknowledgements for each cohort can be found in the Supplementary Note.


Assuntos
Ilhas de CpG , Metilação de DNA , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Feminino , Masculino , Estudo de Associação Genômica Ampla , Predisposição Genética para Doença , Pessoa de Meia-Idade , Epigênese Genética , Fatores de Transcrição Otx/genética , Fatores de Transcrição Otx/metabolismo , Complicações do Diabetes/genética , Perfilação da Expressão Gênica
14.
Materials (Basel) ; 17(6)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38541514

RESUMO

Invisible orthodontic aligners are having a great impact on tooth movement in an aesthetic and effective way. Different techniques, models, and clinical aspects have been studied for their proper use. However, the aim of this research has been to determine the effect of the shaping process on mechanical properties and their bacterial behavior. For this study, 40 original polyurethane plates and 40 identical models, obtained by hot forming the original plates, were used. The static tensile mechanical properties were studied with a Zwick testing machine using testing speeds of 5 mm/min at a temperature of 37 °C. The original plate and the aligner have been studied with a creep test by subjecting the samples to a constant tension of 30 N, and determining the elongation using a long-distance, high-resolution microscope at different time periods between 1 and 720 h. Studies of water absorption has been realized with artificial saliva for 5 h. Bacterial cultures of Streptococcus oralis and Actinomyces viscosus strains were grown on the original plates and on new and used models, to determine the proliferation of each bacterium through metabolic activity, colony-forming units, and LIVE/DEAD assays. The mechanical results showed an increase in the strength of the inserts with respect to the models obtained from 3.44 to 3.95 MPa in the elastic limit and a lower deformation capacity. It has been proven that the transition zone in the creep curves lasts longer in the original plate, producing the rapid increase in deformation at a shorter time (400 h) in the aligner. Therefore, the shaping process reduces the time of dental correction exerted by the aligner. The results of the bacterial culture assays show an increase in the number of bacterial colonies when the aligners have been used and when the polyurethane is conformed due to the internal energy of the model, with respect to the original polyurethane. It has been observed that between the original plate and the aligner there are no statistically significant differences in water absorption and therefore the forming process does not affect water absorption. A slight increase in water absorption can be observed, but after five hours of exposure, the increase is very small.

15.
Int J Med Inform ; 186: 105410, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38507980

RESUMO

BACKGROUND: Chronic Pelvic Pain (CPP) has been described as a public health priority worldwide, and it is among the most prevalent and costly healthcare problems. Graded motor imagery (GMI) is a therapeutic tool that has been successfully used to improve pain in several chronic conditions. GMI therapy is divided into three stages: laterality training (LRJT, Left Right Judgement Task), imagined movements, and mirror therapy. No tool that allows working with LRJT in pelvic floor has been developed to date. OBJECTIVE: This research aims to describe the process followed for the development of a highly usable, multi-language and multi-platform mobile application using GMI with LRJT to improve the treatment of patients with CPP. In addition, this will require achieving two other goals: firstly, to generate 550 pelvic floor images and, subsequently, to carry out an empirical study to objectively classify them into different difficulty levels of. This will allow the app to properly organize and plan the different therapy sessions to be followed by each patient. METHODOLOGY: For the design, evaluation and development of the app, an open methodology of user-centered design (MPIu + a) was applied. Furthermore, to classify and establish the pelvic floor images of the app in different difficulty levels, an observational, cross-sectional study was conducted with 132 volunteers through non-probabilistic sampling. RESULTS: On one hand, applying MPIu+a, a total of 5 phases were required to generate an easy-to-use mobile application. On the other hand, the 550 pelvic floor images were classified into 3 difficulty levels (based on the percentage of correct answers and response time used by the participants in the classification process of each image): Level 1 (191 images with Accuracy = 100 % and RT = [0-2.5] seconds); Level 2 (208 images with Accuracy = 75-100 % and RT = [2.5-5] seconds); and Level 3 (151 images with Accuracy = 50-75 % and RT > 5 s). CONCLUSION: App-Mohedo® is the first multi-platform, multi-language and easy-to-use mobile application that, through GMI with LRJT, and with an adequate bank of images classified into three levels of difficulty, can be used as a complementary therapeutic tool in the treatment of patients with CPP. This work can also serve as an example, model or guide when applying a user-centered methodology, as MPIu + a, to the development of other apps, especially in the field of health.


Assuntos
Aplicativos Móveis , Humanos , Doença Crônica , Estudos Transversais , Lateralidade Funcional/fisiologia , Dor Pélvica/terapia
16.
Clin Exp Dermatol ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38430106

RESUMO

BACKGROUND: Bullous Pemphigoid (BP) is the most common autoimmune blistering disease. Most patients are elderly and associate multiple comorbidities. Topical and systemic corticosteroids are considered as the first-line treatment for BP and immunosuppressors are used as steroid-sparing treatments but both have side effects and contraindications which are even more common in this elderly population. New treatments targeting interleukins and receptors related to BP pathogenesis have been proposed to decrease this side effects while achieving equal or better effectiveness response rates.Omalizumab is a monoclonal antibody that targets IgE that has been proposed for the treatment of BP due to the evidence that IgE autoantibodies play an essential role in BP pathogenesis. OBJECTIVES AND METHODOLOGY: To assess the efficacy and security of Omalizumab for the treatment of BP, we carried out a multicenter, retrospective, observational study including patients diagnosed of BP who received omalizumab for at least 3 months from 15 tertiary hospitals in Spain. IgE levels prior to treatment was measured and we evaluate the possible correlation with clinical response. We excluded patients treated with Omalizumab for less than 3 months as we consider this duration is insufficient for a comprehensive assessment of its efficacy. To evaluate the effectiveness of the treatment we used the percentage of BSA improvement. RESULTS: We included 36 patients. The vast majority associate multiple comorbidities and all patients had used other systemic therapies apart from corticoids before Omalizumab.83% experienced some kind of treatment response and 42% of all patient treated achieved complete response.We did not find any correlation between higher levels and a better response (p=0,1791).All patients tolerated Omalizumab without reported side-effects. CONCLUSIONS: Omalizumab is a good therapeutic alternative for BP as it obtained clinical response in most patients and nearly half of the cases achieving complete response. It showed no side effects which is crucial in elderly patients suffering from BP.

17.
Artigo em Inglês | MEDLINE | ID: mdl-38521444

RESUMO

Hypometabolism is a common strategy employed by resilient species to withstand environmental stressors that would be life-threatening for other organisms. Under conditions such as hypoxia/anoxia, temperature and salinity stress, or seasonal changes (e.g. hibernation, estivation), stress-tolerant species down-regulate pathways to decrease energy expenditures until the return of less challenging conditions. However, it is with the return of these more favorable conditions and the reactivation of basal metabolic rates that a strong increase of reactive oxygen and nitrogen species (RONS) occurs, leading to oxidative stress. Over the last few decades, cases of species capable of enhancing antioxidant defenses during hypometabolic states have been reported across taxa and in response to a variety of stressors. Interpreted as an adaptive mechanism to counteract RONS formation during tissue hypometabolism and reactivation, this strategy was coined "Preparation for Oxidative Stress" (POS). Laboratory experiments have confirmed that over 100 species, spanning 9 animal phyla, apply this strategy to endure harsh environments. However, the challenge remains to confirm its occurrence in the natural environment and its wide applicability as a key survival element, through controlled experimentation in field and in natural conditions. Under such conditions, numerous confounding factors may complicate data interpretation, but this remains the only approach to provide an integrative look at the evolutionary aspects of ecophysiological adaptations. In this review, we provide an overview of representative cases where the POS strategy has been demonstrated among diverse species in natural environmental conditions, discussing the strengths and weaknesses of these results and conclusions.


Assuntos
Antioxidantes , Estresse Oxidativo , Animais , Estresse Oxidativo/fisiologia , Antioxidantes/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Meio Ambiente , Oxigênio , Hipóxia/metabolismo , Espécies Reativas de Nitrogênio
18.
Sci Rep ; 14(1): 6961, 2024 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521859

RESUMO

Artificial Neural Networks (ANNs) have been used in a multitude of real-world applications given their predictive capabilities, and algorithms based on gradient descent, such as Backpropagation (BP) and variants, are usually considered for their optimisation. However, these algorithms have been shown to get stuck at local optima, and they require a cautious design of the architecture of the model. This paper proposes a novel memetic training method for simultaneously learning the ANNs structure and weights based on the Coral Reef Optimisation algorithms (CROs), a global-search metaheuristic based on corals' biology and coral reef formation. Three versions based on the original CRO combined with a Local Search procedure are developed: (1) the basic one, called Memetic CRO; (2) a statistically guided version called Memetic SCRO (M-SCRO) that adjusts the algorithm parameters based on the population fitness; (3) and, finally, an improved Dynamic Statistically-driven version called Memetic Dynamic SCRO (M-DSCRO). M-DSCRO is designed with the idea of improving the M-SCRO version in the evolutionary process, evaluating whether the fitness distribution of the population of ANNs is normal to automatically decide the statistic to be used for assigning the algorithm parameters. Furthermore, all algorithms are adapted to the design of ANNs by means of the most suitable operators. The performance of the different algorithms is evaluated with 40 classification datasets, showing that the proposed M-DSCRO algorithm outperforms the other two versions on most of the datasets. In the final analysis, M-DSCRO is compared against four state-of-the-art methods, demonstrating its superior efficacy in terms of overall accuracy and minority class performance.


Assuntos
Antozoários , Recifes de Corais , Animais , Redes Neurais de Computação , Algoritmos , Aprendizagem
19.
Sci Rep ; 14(1): 5277, 2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438389

RESUMO

Antibiotic resistance is recognised as one of the biggest global threats to human and animal health. Understanding the influence of antibiotics on the canine microbiome is important to know the potential mid-to-long term effects on dysbiosis and mitigate side-effects such as antibiotic-associated diarrhoea. In this study, metronidazole was prescribed to 22 dogs for suspected giardiasis after exhibiting gastrointestinal symptoms such as diarrhoea and/or vomiting. Faecal samples were collected before, during seven days of treatment, and six months post-cessation. Faecal microbiota was assessed with 16S rRNA sequencing. Shannon diversity was reduced for up to three days after the treatment ended, and an altered community persisted for four to six weeks. All dogs recovered to a similar microbiome composition as pre-treatment. Immediately after receiving metronidazole, an increase in the relative abundance of the genera Lactobacillus, Bifidobacterium, and Enterococcus was observed. This may be due to antibiotic resistance commonly exhibited by these organisms. One-to-two weeks post-cessation, several other genera that were sensitive to the antibiotic recovered in abundances, with taxa belonging to the Erysipelotrichaceae family particularly driving composition change. Many of the bacteria initially reduced were associated with carbohydrate fermentation. This suggests scope exists to explore interventions to augment gastrointestinal health and support the re-establishment of the microbiome.


Assuntos
Metronidazol , Microbiota , Humanos , Cães , Animais , Metronidazol/farmacologia , Metronidazol/uso terapêutico , RNA Ribossômico 16S/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Diarreia
20.
Nat Commun ; 15(1): 1563, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378716

RESUMO

A general-purpose photonic processor can be built integrating a silicon photonic programmable core in a technology stack comprising an electronic monitoring and controlling layer and a software layer for resource control and programming. This processor can leverage the unique properties of photonics in terms of ultra-high bandwidth, high-speed operation, and low power consumption while operating in a complementary and synergistic way with electronic processors. These features are key in applications such as next-generation 5/6 G wireless systems where reconfigurable filtering, frequency conversion, arbitrary waveform generation, and beamforming are currently provided by microwave photonic subsystems that cannot be scaled down. Here we report the first general-purpose programmable processor with the remarkable capability to implement all the required basic functionalities of a microwave photonic system by suitable programming of its resources. The processor is fabricated in silicon photonics and incorporates the full photonic/electronic and software stack.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA