679 research outputs found
Comparison of the Magnetic properties of Mn3Fe2Si3O12 as a crystalline garnet and as a glass
The crystalline garnet Mn3Fe2Si3O12 and an amorphous phase of the same
nominal composition are synthesized at high pressure. The magnetic properties
of the two forms are reported. Both phases order antiferromagnetically. The
crystalline phase exhibits a Curie-Weiss theta of -47.2 K, with a sharp
ordering transition at 12 K. The glassy phase exhibits a larger
antiferromagnetic Curie-Weiss theta, of -83.0 K, with a broad ordering
transition observed at 2.5 K. Both phases can be classified as magnetically
frustrated, although the amorphous phase shows a much higher degree of
frustration. The amorphous phase exhibits spin-glass behavior and is determined
to have an actual composition of Mn3Fe2Si3O13.Comment: 14 pages, 7 figures, 2 table
Autonomy, Good Humor and Support Networks, Potential of Community Resilience Intervention in People Victims of the Earthquake in the Calderón Parish
Resilience is a concept widely used in recent years, especially when it comes to evaluating the level of recovery of communities that are hit by natural phenomena. It can be stated that conceptually resilience constitutes the ability to react effectively and quickly to the effects of disasters, being a complex phenomenon to evaluate and define. And although the level of resilience does not necessarily imply greater control of vulnerability, it can be affirmed that the reduction of vulnerable conditions can strengthen and consolidate the resilient capacity of individuals and communities, in the face of the effects of natural disasters
Cytotoxic clinical isolates of Pseudomonas aeruginosa identified during the Steroids for Corneal Ulcers Trial show elevated resistance to fluoroquinolones.
BackgroundTo determine the relationship between type three secretion genotype and fluoroquinolone resistance for P. aeruginosa strains isolated from microbial keratitis during the Steroids for Corneal Ulcers Trial (SCUT) and for two laboratory strains, PA103 and PAO1.MethodsConfirmed P. aeruginosa isolates from the SCUT were divided into exoU(+) or exoU(-). The exoU(+) strains contained the gene encoding ExoU, a powerful phospholipase toxin delivered into host cells by the type three secretion system. Isolates were then assessed for susceptibility to fluoroquinolone, cephalosporin, and aminoglycoside antibiotics using disk diffusion assays. Etest was used to determine the MIC of moxifloxacin and other fluoroquinolones. Laboratory isolates in which the exoU gene was added or deleted were also tested.ResultsA significantly higher proportion of exoU(+) strains were resistant to ciprofloxacin (p = 0.001), gatifloxacin (p = 0.003), and ofloxacin (p = 0.002) compared to exoU(-) isolates. There was no significant difference between exoU(+) or exoU(-) negative isolates with respect to susceptibility to other antibiotics except gentamicin. Infections involving resistant exoU(+) strains trended towards worse clinical outcome. Deletion or acquisition of exoU in laboratory isolates did not affect fluoroquinolone susceptibility.ConclusionsFluoroquinolone susceptibility of P. aeruginosa isolated from the SCUT is consistent with previous studies showing elevated resistance involving exoU encoding (cytotoxic) strains, and suggest worse clinical outcome from infections involving resistant isolates. Determination of exoU expression in clinical isolates of P. aeruginosa may be helpful in directing clinical management of patients with microbial keratitis
Análisis integral de la miel de abeja: desde la composición química hasta la caracterización sensorial
Bee honey is a natural product with a complex chemical composition that varies according to its botanical and geographical origin. This article provides a comprehensive analysis of honey, addressing its chemical composition, which includes sugars, proteins, vitamins, minerals, and bioactive compounds, as well as its impact on organoleptic properties. Analytical techniques used to determine the chemical composition, such as chromatography and spectroscopy, are examined, highlighting their importance for the authenticity and quality of honey. Additionally, sensory evaluation methods are explored, which allow for the characterization of the flavor, aroma, and color of honey, and how these attributes are influenced by factors such as floral origin and processing conditions. Finally, the relevance of a multidimensional approach to honey evaluation is discussed, integrating both chemical composition and sensory characteristics, thereby contributing to a better understanding of its quality and potential as a functional product in food and health.La miel de abeja es un producto natural con una compleja composición química que varía según su origen botánico y geográfico. Este artículo ofrece un análisis integral de la miel, abordando su composición química, que incluye azúcares, proteínas, vitaminas, minerales, y compuestos bioactivos, así como su impacto en las propiedades organolépticas. Se examinan las técnicas analíticas utilizadas para determinar la composición química, como la cromatografía y la espectroscopia, destacando su importancia para la autenticidad y calidad de la miel. Además, se exploran los métodos de evaluación sensorial, que permiten caracterizar el sabor, aroma y color de la miel, y cómo estos atributos son influenciados por factores como el origen floral y las condiciones de procesamiento. Finalmente, se discute la relevancia de un enfoque multidimensional para la evaluación de la miel, que integre tanto la composición química como las características sensoriales, contribuyendo así a un mejor entendimiento de su calidad y su potencial como producto funcional en la alimentación y la salud
Policy-making tool for optimization of transit priority lanes in urban network
Transit improvement is an effective way to relieve traffic congestion and decrease greenhouse gas emissions. Improvement can be in the form of new facilities or giving on-road priority to transit. Although construction of off-road mass transit is not always viable, giving priority to transit can be a low-cost alternative. A framework is introduced for optimization of bus priority at the network level. The framework identifies links on which a bus lane should be located. Allocation of a lane to transit vehicles would increase the utility of transit, although this can be a disadvantage to auto traffic. The approach balances the impact on all stakeholders. Automobile advocates would like to increase traffic road space, and the total travel time of users and total emissions of the network could be reduced by a stronger priority scheme. A bilevel optimization is applied that encompasses an objective function at the upper level and a mode choice, a traffic assignment, and a transit assignment model at the lower level. The proposed optimization helps transport authorities to quantify the outcomes of various strategies of transit priority. A detailed sensitivity analysis is carried out on the relative weight of each factor in the objective function. The proposed framework can also be applied in the context of high-occupancy-vehicle lanes and heavy-vehicle priority lanes
Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement.
Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut).Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist.When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health
Pathogenesis of progressive scarring trachoma in Ethiopia and Tanzania and its implications for disease control: two cohort studies.
BACKGROUND: Trachoma causes blindness through a conjunctival scarring process initiated by ocular Chlamydia trachomatis infection; however, the rates, drivers and pathophysiological determinants are poorly understood. We investigated progressive scarring and its relationship to conjunctival infection, inflammation and transcript levels of cytokines and fibrogenic factors. METHODOLOGY/PRINCIPAL FINDINGS: We recruited two cohorts, one each in Ethiopia and Tanzania, of individuals with established trachomatous conjunctival scarring. They were followed six-monthly for two years, with clinical examinations and conjunctival swab sample collection. Progressive scarring cases were identified by comparing baseline and two-year photographs, and compared to individuals without progression. Samples were tested for C. trachomatis by PCR and transcript levels of S100A7, IL1B, IL13, IL17A, CXCL5, CTGF, SPARCL1, CEACAM5, MMP7, MMP9 and CD83 were estimated by quantitative RT-PCR. Progressive scarring was found in 135/585 (23.1%) of Ethiopian participants and 173/577 (30.0%) of Tanzanian participants. There was a strong relationship between progressive scarring and increasing inflammatory episodes (Ethiopia: OR 5.93, 95%CI 3.31-10.6, p<0.0001. Tanzania: OR 5.76, 95%CI 2.60-12.7, p<0.0001). No episodes of C. trachomatis infection were detected in the Ethiopian cohort and only 5 episodes in the Tanzanian cohort. Clinical inflammation, but not scarring progression, was associated with increased expression of S100A7, IL1B, IL17A, CXCL5, CTGF, CEACAM5, MMP7, CD83 and reduced SPARCL1. CONCLUSIONS/SIGNIFICANCE: Scarring progressed in the absence of detectable C. trachomatis, which raises uncertainty about the primary drivers of late-stage trachoma. Chronic conjunctival inflammation appears to be central and is associated with enriched expression of pro-inflammatory factors and altered expression of extracellular matrix regulators. Host determinants of scarring progression appear more complex and subtle than the features of inflammation. Overall this indicates a potential role for anti-inflammatory interventions to interrupt progression and the need for trichiasis disease surveillance and surgery long after chlamydial infection has been controlled at community level
High-Dose Antibiotics in Intensive Care: A Review of Their Role in Combatting and Contributing to Antimicrobial Resistance
Introduction. High-dose antibiotic regimens are commonly employed to improve outcomes in critically ill patients with severe infections; however, their direct impact on antimicrobial resistance (AMR) remains underexplored. Methods. This systematic review analyzed randomized controlled trials (RCTs) published between 2020 and 2024, focusing on high-dose regimens for gram-negative bacterial infections, cellulitis, and ventilated hospital-acquired bacterial pneumonia (vHABP). A comprehensive search was conducted using the Web of Science and PubMed databases, yielding four studies that met the inclusion criteria. Results. The results suggest that while high-dose regimens reduce treatment failure and improve clinical outcomes, they are associated with higher adverse effects and may contribute to antibiotic-resistant bacteria. Notably, none of the studies directly assessed the molecular or epidemiological mechanisms linking high-dose regimens to AMR, underscoring a significant gap in the current literature. Conclusion. Further research is required to elucidate these mechanisms and establish evidence-based guidelines that balance immediate clinical benefits with long-term public health concerns
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