13 research outputs found
3-D printed band-pass combline filter
This article describes a fourth-order 3-D printed combline filter with a Chebyshev response, operating at central frequency 3 GHz and having a 3% fractional bandwidth. The filter is designed using the coupling matrix theory, fabricated, and experimental results are presented. Comparison between simulations and measurements shows good agreement
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Effect of ultrapure lipopolysaccharides derived from diverse bacterial species on the modulation of platelet activation
Platelets are small circulating blood cells that play essential roles in the maintenance of haemostasis via blood clotting. However, they also play critical roles in the regulation of innate immune responses. Inflammatory receptors, specifically Toll-like receptor (TLR)-4, have been reported to modify platelet reactivity. A plethora of studies have reported controversial functions of TLR4 in the modulation of platelet function using various chemotypes and preparations of its ligand, lipopolysaccharide (LPS). The method of preparation of LPS may explain these discrepancies however this is not fully understood. Hence, to determine the impact of LPS on platelet activation, we used ultrapure preparations of LPS from Escherichia coli (LPSEC), Salmonella minnesota (LPSSM), and Rhodobacter sphaeroides (LPSRS) and examined their actions under diverse experimental conditions in human platelets. LPSEC did not affect platelet activation markers such as inside-out signalling to integrin IIb3 or P-selectin exposure upon agonist-induced activation in platelet-rich plasma or whole blood whereas LPSSM and LPSRS inhibited platelet activation under specific conditions at supraphysiological concentrations. Overall, our data demonstrate that platelet activation is not largely influenced by any of the ultrapure LPS chemotypes used in this study on their own except under certain conditions
Amphiphilic Guanidinocalixarenes Inhibit Lipopolysaccharide (LPS)- and Lectin-Stimulated Toll-like Receptor 4 (TLR4) Signaling
We
recently reported on the activity of cationic amphiphiles in
inhibiting TLR4 activation and subsequent production of inflammatory
cytokines in cells and in animal models. Starting from the assumption
that opportunely designed cationic amphiphiles can behave as CD14/MD-2
ligands and therefore modulate the TLR4 signaling, we present here
a panel of amphiphilic guanidinocalixarenes whose structure
was computationally optimized to dock into MD-2 and CD14 binding sites.
Some of these calixarenes were active in inhibiting, in a dose-dependent
way, the LPS-stimulated TLR4 activation and TLR4-dependent cytokine
production in human and mouse cells. Moreover, guanidinocalixarenes
also inhibited TLR4 signaling when TLR4 was activated by a non-LPS
stimulus, the plant lectin PHA. While the activity of guanidinocalixarenes
in inhibiting LPS toxic action has previously been related to their
capacity to bind LPS, we suggest a direct antagonist effect of calixarenes
on TLR4/MD-2 dimerization, pointing at the calixarene moiety as a
potential scaffold for the development of new TLR4-directed therapeutics
Feasibility of a prehabilitation programme dedicated to older patients with cancer before complex medical–surgical procedures: the PROADAPT pilot study protocol
Background Ageing is associated with an increased prevalence of comorbidities and sarcopenia as well as a decline of functional reserve of multiple organ systems, which may lead, in the context of the disease-related and/or treatment-related stress, to functional deconditioning. The multicomponent ‘Prehabilitation & Rehabilitation in Oncogeriatrics: Adaptation to Deconditioning risk and Accompaniment of Patients’ Trajectories (PROADAPT)’ intervention was developed multiprofessionally to implement prehabilitation in older patients with cancer.Methods The PROADAPT pilot study is an interventional, non-comparative, prospective, multicentre study. It will include 122 patients oriented to complex medical–surgical curative procedures (major surgery or radiation therapy with or without chemotherapy). After informed consent, patients will undergo a comprehensive geriatric assessment and will be offered a prehabilitation kit that includes an advice booklet with personalised objectives and respiratory rehabilitation devices. Patients will then be called weekly and monitored for physical and respiratory rehabilitation, preoperative renutrition, motivational counselling and iatrogenic prevention. Six outpatient visits will be planned: at inclusion, a few days before the procedure and at 1, 3, 6 and 12 months after the end of the procedure. The main outcome of the study is the feasibility of the intervention, defined as the ability to perform at least one of the components of the programme. Clinical data collected will include patient-specific and cancer-specific characteristics.Ethics and dissemination The study protocol was approved by the Ile de France 8 ethics committee on 5 June 2018. The results of the primary and secondary objectives will be published in peer-reviewed journals.Trial registration number NCT03659123. Pre-results of the trial