64 research outputs found

    Ligand-Mediated Control of the Surface Oxidation States of Copper Nanoparticles Produced by Laser Ablation

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    We report on studies that demonstrate how the chemical composition of the surface of copper nanoparticles (CuNPs) - in terms of percentage copper(I/II) oxides - can be varied by the presence of N-donor ligands during their formation via laser ablation. Changing the chemical composition thus allows systematic tuning of the surface plasmon resonance (SPR) transition. The trialed ligands include pyridines, tetrazoles, and alkylated tetrazoles. CuNPs formed in the presence of pyridines, and alkylated tetrazoles exhibit a SPR transition only slightly blue shifted with respect to CuNPs formed in the absence of any ligand. On the other hand, the presence of tetrazoles results in CuNPs characterized by a significant blue shift of the order of 50-70 nm. By comparing these data also with the SPR of CuNPs formed in the presence of carboxylic acids and hydrazine, this work demonstrates that the blue shift in the SPR is due to tetrazolate anions providing a reducing environment to the nascent CuNPs, thus preventing the formation of copper(II) oxides. This conclusion is further supported by the fact that both AFM and TEM data indicate only small variations in the size of the nanoparticles, which is not enough to justify a 50-70 nm blue-shift of the SPR transition. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) studies further confirm the absence of Cu(II)-containing CuNPs when prepared in the presence of tetrazolate anions

    Unprecedented staining of polar lipids by a luminescent rhenium complex revealed by FTIR microspectroscopy in adipocytes.

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    Fourier transform infrared (FTIR) microspectroscopy and confocal imaging have been used to demonstrate that the neutral rhenium(i) tricarbonyl 1,10-phenanthroline complex bound to 4-cyanophenyltetrazolate as the ancillary ligand is able to localise in regions with high concentrations of polar lipids such as phosphatidylethanolamine (PE), sphingomyelin, sphingosphine and lysophosphatidic acid (LPA) in mammalian adipocytes

    Intravenous fluid restriction after major abdominal surgery: a randomized blinded clinical trial

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    Background: Intravenous (IV) fluid administration is an essential part of postoperative care. Some studies suggest that a restricted post-operative fluid regime reduces complications and postoperative hospital stay after surgery. We investigated the effects of postoperative fluid restriction in surgical patients undergoing major abdominal surgery. Methods: In a blinded randomized trial, 62 patients (ASA I-III) undergoing elective major abdominal surgical procedures in a university hospital were allocated either to a restricted (1.5 L/24 h) or a standard postoperative IV fluid regime (2.5 L/24 h). Primary endpoint was length of postoperative hospital stay (PHS). Secondary endpoints included postoperative complications and time to restore gastric functions. Results: After a 1-year inclusion period, an unplanned interim analysis was made because of many protocol violations due to patient deterioration. In the group with the restricted regime we found a significantly increased PHS (12.3 vs. 8.3 days; p = 0.049) and significantly more major complications: 12 in 30 (40%) vs. 5 in 32 (16%) patients (Absolute Risk Increase: 0.24 [95%CI: 0.03 to 0.46], i.e. a number needed to harm of 4 [95%CI: 2-33]). Therefore, the trial was stopped prematurely. Intention to treat analysis showed no differences in time to restore gastric functions between the groups. Conclusion: Restricted postoperative IV fluid management, as performed in this trial, in patients undergoing major abdominal surgery appears harmful as it is accompanied by an increased risk of major postoperative complications and a prolonged postoperative hospital stay

    A survey of the workload generated by older surgical patients referred to on-call medical registrars—SNAP-3

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    \ua9 2025 The Authors. Background: Older surgical patients who develop medical problems are commonly referred to medical teams, which can be proactive physician-led teams or through reactive referral to the on-call medical registrar. Methods: A cross-sectional survey of on-call medical registrars who received referrals from surgical teams was conducted in March–June 2022 at 140 NHS hospitals. It focused on the workload derived from referrals of older surgical patients to on-call medical registrars, excluding referrals to existing services such as perioperative medicine, orthogeriatric, or medical specialty teams. To minimise recall bias, completion of the survey was encouraged regardless of whether a registrar had received a referral. The aim of this survey was to estimate the unplanned, acute workload generated by older surgical patients requiring referral to on-call medical registrars. The survey also aimed to estimate the prevalence and nature of training in perioperative medicine amongst medical registrars. Results: During an on-call shift, 41.3% (266/644) of medical registrars received at least one referral regarding an older surgical patient. The commonest indications were arrhythmia, acute respiratory problems, electrolyte abnormalities, suspected myocardial infarction, sepsis, and delirium. Three-quarters of registrars reported not receiving training in perioperative management of older patients. Conclusions: The findings highlight the significant workload and training gaps faced by medical registrars in managing older surgical patients. Bridging the gap between national recommendations and local services may reduce demands on on-call registrars and improve care

    Antibodies and sperm survival in the female tract of the mouse and rabbit.

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    Summary. Rabbit and mouse spermatozoa from male and female tracts have been examined for their species-antigenic surface character, and for adherent antibodies, by double immunofluorescence techniques. Mouse spermatozoa from the ductus deferens showed an area over the acrosome which was positive to anti-mouse serum that had been absorbed with some male mouse somatic tissues including blood, but those from the uterus and oviduct were not stained. Spermatozoa from the uterus were shown to have an antibody coat on the acrosome, with anti-mouse IgG, but those from the ductus deferens and oviduct did not. Rabbit spermatozoa were more variable but their activity was similar: ejaculated spermatozoa sometimes already had antibody ofmale origin; the majority of the spermatozoa arriving early in the uterus were coated, but in general those that attained the oviducts were not coated. The results are interpreted as evidence for selection by the female tract of a small antigenically different population; the majority of sperma-tozoa are rejected and/or destroyed

    DNA Polymorphisms - Practical use

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