Experimental and numerical study of vacuum resin infusion of stiffened carbon fiber reinforced panels

Liquid resin infusion processes are becoming attractive for aeronautic applications as an alternative to conventional autoclave-based processes. They still present several challenges, which can be faced only with an accurate simulation able to optimize the process parameters and to replace traditional time-consuming trial-and-error procedures. This paper presents an experimentally validated model to simulate the resin infusion process of an aeronautical component by accounting for the anisotropic permeability of the reinforcement and the chemophysical and rheological changes in the crosslinking resin. The input parameters of the model have been experimentally determined. The experimental work has been devoted to the study of the curing kinetics and chemorheological behavior of the thermosetting epoxy matrix and to the determination of both the in-plane and out-of-plane permeability of two carbon fiber preforms using an ultrasonic-based method, recently developed by the authors. The numerical simulation of the resin infusion process involved the modeling of the resin flow through the reinforcement, the heat exchange in the part and within the mold, and the crosslinking reaction of the resin. The time necessary to fill the component has been measured by an optical fiber-based equipment and compared with the simulation results

Olive Mill Wastewater Valorization in Multifunctional Biopolymer Composites for Antibacterial Packaging Application

Olive mill wastewater (OMW) is the aqueous waste derived from the production of virgin olive oil. OMW typically contains a wide range of phenol-type molecules, which are natural antioxidants and/or antibacterials. In order to exploit the bioactive molecules and simultaneously decrease the environmental impact of such a food waste stream, OMW has been intercalated into the host structure of ZnAl layered double hydroxide (LDH) and employed as an integrative filler for the preparation of poly(butylene succinate) (PBS) composites by in situ polymerization. From the view point of the polymer continuous phase as well as from the side of the hybrid filler, an investigation was performed in terms of molecular and morphological characteristics by gel permeation chromatography (GPC) and X-ray diffraction (XRD); also, the thermal and mechanical properties were evaluated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMTA). Antibacterial properties have been assessed against a Gram-positive and a Gram-negative bacterium, Staphylococcus aureus and Escherichia coli, respectively, as representatives of potential agents of foodborne illnesses

a transverse and longitudinal mr imaging voxel based morphometry study in patients with primary cervical dystonia

BACKGROUND AND PURPOSE: Findings of standard MR imaging examinations are usually normal in primary CD. These findings are now increasingly challenged by studies using advanced neuroimaging techniques detecting abnormalities in brain areas that may be functionally involved in the pathophysiology of CD. Our purpose was to evaluate GM volumes in patients with CD at baseline and 5 years later. MATERIALS AND METHODS: We enrolled 19 patients (F/M = 15:4, mean age = 53.2 + 11.2 years), 12 of whom were studied at baseline and again approximately 5 years later. Twenty-eight healthy volunteers acted as controls (F/M = 17:11, mean age = 47.5 + 15.6 years). The subjects were imaged with a 1.5T scanner by using a 3D T1-weighted sequence on 150 contiguous axial 1-mm-thick sections to apply VBM. RESULTS: At entry, VBM analysis disclosed significantly lower GM volumes in the left caudate head and putamen and in the premotor and primary sensorimotor cortices bilaterally in patients than in controls. No correlation was found between decreased GM volumes and patient age, severity of dystonia, or disease duration. At the 5-year follow-up, GM volumes in the left primary sensorimotor cortex in patients had decreased significantly from baseline. CONCLUSIONS: The findings obtained at entry and after a 5-year follow-up consistently showed decreased caudate, putamen, and sensorimotor cortex GM volumes in patients with CD, and they probably play a pathophysiologic role in CD

Rational Design of Selective and Bioactive Inhibitors of the Mycobacterium Tuberculosis Proteasome

The 20S core particle of the proteasome in Mycobacterium tuberculosis (Mtb) is a promising, yet unconventional, drug target. This multimeric peptidase is not essential, yet degrades proteins that have become damaged and toxic via reactions with nitric oxide (and/or the associated reactive nitrogen intermediates) produced during the host immune response. Proteasome inhibitors could render Mtb susceptible to the immune system, but they would only be therapeutically viable if they do not inhibit the essential 20S counterpart in humans. Selective inhibitors of the Mtb 20S were designed and synthesized on the bases of both its unique substrate preferences and the structures of substrate-mimicking covalent inhibitors of eukaryotic proteasomes called syringolins. Unlike the parent syringolins, the designed analogues weakly inhibit the human 20S (Hs 20S) proteasome and preferentially inhibit Mtb 20S over the human counterpart by as much as 74-fold. Moreover, they can penetrate the mycobacterial cell envelope and render Mtb susceptible to nitric oxide-mediated stress. Importantly, they do not inhibit the growth of human cell lines in vitro and thus may be starting points for tuberculosis drug development.National Institutes of Health (U.S.) (Grant AI-16892

Visceral Leishmaniasis: Epidemiology, Diagnosis, and Treatment Regimens in Different Geographical Areas with a Focus on Pediatrics

Visceral Leishmaniasis (VL) is a vector-borne disease caused by an intracellular protozoa of the genus Leishmania that can be lethal if not treated. VL is caused by Leishmania donovani in Asia and in Eastern Africa, where the pathogens’ reservoir is represented by humans, and by Leishmania infantum in Latin America and in the Mediterranean area, where VL is a zoonotic disease and dog is the main reservoir. A part of the infected individuals become symptomatic, with irregular fever, splenomegaly, anemia or pancytopenia, and weakness, whereas others are asymptomatic. VL treatment has made progress in the last decades with the use of new drugs such as liposomal amphotericin B, and with new therapeutic regimens including monotherapy or a combination of drugs, aiming at shorter treatment duration and avoiding the development of resistance. However, the same treatment protocol may not be effective all over the world, due to differences in the infecting Leishmania species, so depending on the geographical area. This narrative review presents a comprehensive description of the clinical picture of VL, especially in children, the diagnostic approach, and some insight into the most used pharmacological therapies available worldwide

Long-term Results of a Randomized Controlled Trial Analyzing the Role of Systematic Pre-operative Coronary Angiography before Elective Carotid Endarterectomy in Patients with Asymptomatic Coronary Artery Disease

ObjectivesTo evaluate the potential benefit of systematic preoperative coronary-artery angiography followed by selective coronary-artery revascularization on the incidence of myocardial infarction (MI) in patients undergoing carotid endarterectomy (CEA) without a previous history of coronary artery disease (CAD).MethodsWe randomised 426 patients who were candidates for CEA, with no history of CAD, a normal electrocardiogram (ECG), and a normal cardiac ultrasound. In group A (n = 216) all patients underwent coronary angiography before CEA. In group B (n = 210) CEA was performed without coronary angiography. Patients were not blinded for relevant assessments during follow-up. Primary end-point was the occurrence of MI at 3.5 years. The secondary end-point was the overall survival rate. Median length of follow-up was 6.2 years.ResultsIn group A, coronary angiography revealed significant coronary artery stenosis in 68 patients (31.5%). Among them, 66 underwent percutaneous Intervention (PCI) prior to CEA and 2 received combined CEA and coronary-artery bypass grafting (CABG). Postoperatively, no MI was observed in group A, whereas 6 MI occurred in group B, one of which was fatal (p = .01).During the study period, 3 MI occurred in group A (1.4%) and 33 were observed in group B (15.7%), 6 of which were fatal. The Cox model demonstrated a reduced risk of MI for patients in group A receiving coronary angiography (HR,.078; 95% CI, 0.024-0.256; p < .001). In addition, patients with diabetes and patients <70 years presented with an increased risk of MI. Survival analysis at 6 years by Kaplan-Meier estimates was 95.6 ± 3.2% in Group A and 89.7 ± 3.7% in group B (Log Rank = 6.54, p = .01).ConclusionsIn asymptomatic coronary-artery patients, systematic coronary angiography prior to CEA followed by selective PCI or CABG significantly reduces the incidence of late MI and increases long-term survival. (ClinicalTrials.gov number, NCT02260453)

Increased risk of acquisition of New Delhi metallo-beta-lactamase-producing carbapenem-resistant enterobacterales (Ndm-cre) among a cohort of covid-19 patients in a teaching hospital in Tuscany, Italy

We describe the epidemiology of New Delhi Metallo-Beta-Lactamase-Producing Carbapenem-Resistant Enterobacterales (NDM-CRE) colonization/infection in a cohort of COVID-19 patients in an Italian teaching hospital. These patients had an increased risk of NDM-CRE acquisition versus the usual patients (75.9 vs. 25.3 cases/10,000 patient days). The co-infection significantly increased the duration of hospital stay (32.9 vs. 15.8 days)

Cohomology of bundles on homological Hopf manifold

We discuss the properties of complex manifolds having rational homology of $S^1 \times S^{2n-1}$ including those constructed by Hopf, Kodaira and Brieskorn-van de Ven. We extend certain previously known vanishing properties of cohomology of bundles on such manifolds.As an application we consider degeneration of Hodge-deRham spectral sequence in this non Kahler setting.Comment: To appear in Proceedings of 2007 conference on Several complex variables and Complex Geometry. Xiamen. Chin

The histone H3 lysine 27-specific demethylase Jmjd3 is required for neural commitment

Patterns of methylation at lysine 4 and 27 of histone H3 have been associated with states of gene activation and repression that are developmentally regulated and are thought to underlie the establishment of lineage specific gene expression programs. Recent studies have provided fundamental insight into the problem of lineage specification by comparing global changes in chromatin and transcription between ES and neural stem (NS) cells, points respectively of departure and arrival for neural commitment. With these maps of the differentiated state in place, a central task is now to unravel the chromatin dynamics that enables these differentiation transitions. In particular, the observation that lineage-specific genes repressed in ES cells by Polycomb-mediated H3-K27 trimethylation (H3-K27me3) are demethylated and derepressed in differentiated cells posited the existence of a specific H3-K27 demethylase.In order to gain insight into the epigenetic transitions that enable lineage specification, we investigated the early stages of neural commitment using as model system the monolayer differentiation of mouse ES cells into neural stem (NS) cells. Starting from a comprehensive profiling of JmjC-domain genes, we report here that Jmjd3, recently identified as a H3-K27me3 specific demethylase, controls the expression of key regulators and markers of neurogenesis and is required for commitment to the neural lineage.Our results demonstrate the relevance of an enzymatic activity that antagonizes Polycomb regulation and highlight different modalities through which the dynamics of H3-K27me3 is related to transcriptional output. By showing that the H3-K27 demethylase Jmjd3 is required for commitment to the neural lineage and that it resolves the bivalent domain at the Nestin promoter, our work confirms the functional relevance of bivalent domain resolution that had been posited on the basis of the genome-wide correlation between their controlled resolution and differentiation. In addition, our data indicate that the regulation of H3-K27me3 is highly gene- and context- specific, suggesting that the interplay of methyltransferases and demethylases enables the fine-tuning more than the on/off alternation of methylation states