Synthesis of Supported Catalysts by Dry Impregnation in Fluidized Bed

The synthesis of catalytic or not composite materials by dry impregnation in fluidized bed is described. This process can be carried out under mild conditions from solutions of organometallic precursors or colloidal solutions of preformed nanoparticles giving rise to reproducible metallic nanoparticles containing composite materials with a high reproducibility. The adequate choice of the reaction conditions makes possible to deposit uniformly the metal precursor within the porous matrix or on the support surface. When the ratio between the drying time and the capillary penetration time (tsec/tcap) is higher than 10, the impregnation under soft drying conditions leads to a homogeneous deposit inside the pores of the particles of support. The efficiency of the metal deposition is close to 100%, and the size of the formed metal nanoparticles is controlled by the pores diameter. Finally, some of the presented composite materials have been tested as catalysts: iron-based materials were used in carbon-nanotubes synthesis, while Pd and Rh composite materials have been investigated in hydrogenation reactions

Theoretical analysis of perching and hovering maneuvers

Unsteady aerodynamic phenomena are encountered in a large number of modern aerospace and non-aerospace applications. Leading edge vortices (LEVs) are of particular interest because of their large impact on the forces and performance. In rotorcraft applications, they cause large vibrations and torsional loads (dynamic stall), affecting the performance adversely. In insect flight however, they contribute positively by enabling high-lift flight. Identifying the conditions that result in LEV formation and modeling their effects on the flow is an important ongoing challenge. Perching (airfoil decelerates to rest) and hovering (zero freestream velocity) maneuvers are of special interest. In earlier work by the authors, a Leading Edge Suction Parameter (LESP) was developed to predict LEV formation for airfoils undergoing arbitrary variation in pitch and plunge at a constant freestream velocity. In this research, the LESP criterion is extended to situations where the freestream velocity is varying or zero. A point-vortex model based on this criterion is developed and results from the model are compared against those from a computational fluid dynamics (CFD) method. Abstractions of perching and hovering maneuvers are used to validate the low-order model's performance in highly unsteady vortex-dominated flows, where the time-varying freestream/translational velocity is small in magnitude compared to the other contributions to the velocity experienced by the leading edge region of the airfoil. Time instants of LEV formation, flow topologies and force coefficient histories for the various motion kinematics from the low-order model and CFD are obtained and compared. The LESP criterion is seen to be successful in predicting the start of LEV formation and the point-vortex method is effective in modeling the flow development and forces on the airfoil. Typical run-times for the low-order method are between 30-40 seconds, making it a potentially convenient tool for control/design applications

Melatonin potentials against viral infections including COVID-19: Current evidence and new findings

Viral infections are dangerous diseases for human health worldwide, which lead to significant morbidity and mortality each year. Because of their importance and the lack of effective therapeutic approaches, further attempts should be made to discover appropriate alternative or complementary treatments. Melatonin, a multifunctional neurohormone mainly synthesized and secreted by the pineal gland, plays some roles in the treatment of viral infections. Regarding a deadly outbreak of COVID-19 across the world, we decided to discuss melatonin functions against various viral infections including COVID-19. Therefore, in this review, we summarize current evidence on melatonin therapy for viral infections with focus on possible underlying mechanisms of melatonin actions. © 2020 Elsevier B.V

Melatonin potentials against viral infections including COVID-19: Current evidence and new findings

Viral infections are dangerous diseases for human health worldwide, which lead to significant morbidity and mortality each year. Because of their importance and the lack of effective therapeutic approaches, further attempts should be made to discover appropriate alternative or complementary treatments. Melatonin, a multifunctional neurohormone mainly synthesized and secreted by the pineal gland, plays some roles in the treatment of viral infections. Regarding a deadly outbreak of COVID-19 across the world, we decided to discuss melatonin functions against various viral infections including COVID-19. Therefore, in this review, we summarize current evidence on melatonin therapy for viral infections with focus on possible underlying mechanisms of melatonin actions. © 2020 Elsevier B.V

Melatonin: New insights on its therapeutic properties in diabetic complications

Diabetes and diabetic complications are considered as leading causes of both morbidity and mortality in the world. Unfortunately, routine medical treatments used for affected patients possess undesirable side effects, including kidney and liver damages as well as gastrointestinal adverse reactions. Therefore, exploring the novel therapeutic strategies for diabetic patients is a crucial issue. It has been recently shown that melatonin, as main product of the pineal gland, despite its various pharmacological features including anticancer, anti-Aging, antioxidant and anti-inflammatory effects, exerts anti-diabetic properties through regulating various cellular mechanisms. The aim of the present review is to describe potential roles of melatonin in the treatment of diabetes and its complications. © 2020 The Author(s)

Melatonin in the treatment of fibromyalgia symptoms: A systematic review

The available pharmacological modalities for the treatment of fibromyalgia (FM) are associated with a variety of adverse effects and limited benefits. In this study, we systematically reviewed the impact of melatonin in the treatment of FM. Interventional studies, either controlled or uncontrolled and randomized or non-randomized, were included. PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library were searched without time limitation. Primary outcome measures were the effect of melatonin on the disease impact, pain, sleep quality, tender point count, fatigue, anxiety, stiffness, and depression in FM patients. Four studies, reporting the effect of melatonin on 98 patients, were eligible to include. All the studies reported the positive effect of melatonin on the FM symptoms. No major adverse event was reported. A significant level of heterogeneity was observed between the studies. Therefore, further high-quality controlled clinical trials are needed to understand the role of melatonin in FM treatment fully. © 2019 Elsevier Lt

The Consensus from the Mycobacterium avium ssp. paratuberculosis (MAP) Conference 2017.

On March 24 and 25, 2017 researchers and clinicians from around the world met at Temple University in Philadelphia to discuss the current knowledge of Mycobacterium avium ssp. paratuberculosis (MAP) and its relationship to human disease. The conference was held because of shared concern that MAP is a zoonotic bacterium that poses a threat not only to animal health but also human health. In order to further study this problem, the conferees discussed ways to improve MAP diagnostic tests and discussed potential future anti-MAP clinical trials. The conference proceedings may be viewed on the www.Humanpara.org website. A summary of the salient work in this field is followed by recommendations from a majority of the conferees

Design of experiments to study the impact of process parameters on droplet size and development of non-invasive imaging techniques in tablet coating

Atomisation of an aqueous solution for tablet film coating is a complex process with multiple factors determining droplet formation and properties. The importance of droplet size for an efficient process and a high quality final product has been noted in the literature, with smaller droplets reported to produce smoother, more homogenous coatings whilst simultaneously avoiding the risk of damage through over-wetting of the tablet core. In this work the effect of droplet size on tablet film coat characteristics was investigated using X-ray microcomputed tomography (XμCT) and confocal laser scanning microscopy (CLSM). A quality by design approach utilising design of experiments (DOE) was used to optimise the conditions necessary for production of droplets at a small (20 μm) and large (70 μm) droplet size. Droplet size distribution was measured using real-time laser diffraction and the volume median diameter taken as a response. DOE yielded information on the relationship three critical process parameters: pump rate, atomisation pressure and coating-polymer concentration, had upon droplet size. The model generated was robust, scoring highly for model fit (R2 = 0.977), predictability (Q2 = 0.837), validity and reproducibility. Modelling confirmed that all parameters had either a linear or quadratic effect on droplet size and revealed an interaction between pump rate and atomisation pressure. Fluidised bed coating of tablet cores was performed with either small or large droplets followed by CLSM and XμCT imaging. Addition of commonly used contrast materials to the coating solution improved visualisation of the coating by XμCT, showing the coat as a discrete section of the overall tablet. Imaging provided qualitative and quantitative evidence revealing that smaller droplets formed thinner, more uniform and less porous film coats

Activation of adherent vascular neutrophils in the lung during acute endotoxemia

BACKGROUND: Neutrophils constitute the first line of defense against invading microorganisms. Whereas these cells readily undergo apoptosis under homeostatic conditions, their survival is prolonged during inflammatory reactions and they become biochemically and functionally activated. In the present study, we analyzed the effects of acute endotoxemia on the response of a unique subpopulation of neutrophils tightly adhered to the lung vasculature. METHODS: Rats were treated with 5 mg/kg lipopolysaccharide (i.v.) to induce acute endotoxemia. Adherent neutrophils were isolated from the lung vasculature by collagenase digestion and sequential filtering. Agarose gel electrophoresis, RT-PCR, western blotting and electrophoretic mobility shift assays were used to evaluate neutrophil activity. RESULTS: Adherent vascular neutrophils isolated from endotoxemic animals exhibited decreased apoptosis when compared to cells from control animals. This was associated with a marked increase in expression of the anti-apoptotic protein, Mcl-1. Cells isolated 0.5–2 hours after endotoxin administration were more chemotactic than cells from control animals and expressed increased tumor necrosis factor-alpha and cyclooxygenase-2 mRNA and protein, demonstrating that they are functionally activated. Endotoxin treatment of the animals also induced p38 and p44/42 mitogen activated protein kinases in the adherent lung neutrophils, as well as nuclear binding activity of the transcription factors, NF-κB and cAMP response element binding protein. CONCLUSION: These data demonstrate that adherent vascular lung neutrophils are highly responsive to endotoxin and that pathways regulating apoptosis and cellular activation are upregulated in these cells

Evodiamine Inhibits Insulin-Stimulated mTOR-S6K Activation and IRS1 Serine Phosphorylation in Adipocytes and Improves Glucose Tolerance in Obese/Diabetic Mice

Evodiamine, an alkaloid extracted from the dried unripe fruit of the tree Evodia rutaecarpa Bentham (Rutaceae), reduces obesity and insulin resistance in obese/diabetic mice; however, the mechanism underlying the effect of evodiamine on insulin resistance is unknown. This study investigated the effect of evodiamine on signal transduction relating to insulin resistance using obese/diabetic KK-Ay mice and an in vitro adipocyte culture. There is a significant decrease in the mammalian target of rapamycin (mTOR) and ribosomal S6 protein kinase (S6K) signaling in white adipose tissue (WAT) in KK-Ay mice treated with evodiamine, in which glucose tolerance is improved. In addition, reduction of insulin receptor substrate 1 (IRS1) serine phosphorylation, an indicator of insulin resistance, was detected in their WAT, suggesting suppression of the negative feedback loop from S6K to IRS1. As well as the stimulation of IRS1 and Akt serine phosphorylation, insulin-stimulated phosphorylation of mTOR and S6K is time-dependent in 3T3-L1 adipocytes, whereas evodiamine does not affect their phosphorylation except for an inhibitory effect on mTOR phosphorylation. Moreover, evodiamine inhibits the insulin-stimulated phosphorylation of mTOR and S6K, leading to down-regulation of IRS1 serine phosphorylation in the adipocytes. Evodiamine also stimulates phosphorylation of AMP-activated protein kinase (AMPK), an important regulator of energy metabolism, which may cause down-regulation of mTOR signaling in adipocytes. A similar effect on AMPK, mTOR and IRS1 phosphorylation was found in adipocytes treated with rosiglitazone. These results suggest evodiamine improves glucose tolerance and prevents the progress of insulin resistance associated with obese/diabetic states, at least in part, through inhibition of mTOR-S6K signaling and IRS1 serine phosphorylation in adipocytes