Tailoring porosity and rotational dynamics in a series of octacarboxylate metal-organic frameworks

Modulation and precise control of porosity of metal-organic frameworks (MOFs) are of critical importance to their materials function. Here we report the first modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs show absence of network interpenetration, robust structures and permanent porosity. Interestingly, activated MFM-185a shows a record high BET surface area of 4734 m2 g-1 for an octacarboxylate MOF. These MOFs show remarkable CH4 and CO2 adsorption properties, notably with simultaneously high gravimetric and volumetric deliverable CH4 capacities of 0.24 g g-1 and 163 v/v (298 K, 5-65 bar) recorded for MFM-185a due to selective elongation of tubular cages. Dynamics of molecular rotors in deuterated MFM-180a-d16 and MFM-181a-d16 were investigated by variable-temperature 2H solid state NMR spectroscopy to reveal the reorientation mechanisms within these materials. Analysis of the flipping modes of the mobile phenyl groups on the linkers, their rotational rates and transition temperatures, paves the way to controlling and understanding the role of molecular rotors through organic linker design within porous MOF materials

Translation and Validation of the Greek Food Allergy Quality of Life Questionnaire—Parent Form

Background: The prevalence of food allergy is increasing, posing a significant health concern. Assessing health-related quality of life (HRQOL) in individuals with food allergies is crucial, and various questionnaires exist for this purpose. However, translation and validation of these tools are necessary to ensure cultural relevance. This study aimed to translate the FAQLQ-PF into Greek and perform a cross-sectional validation to assess its effectiveness in evaluating HRQOL among Greek children with food allergies. Methods: Parents of children aged 0 to 12 years diagnosed with food allergy completed the Greek version of the FAQLQ-PF, consisting of 30 items across three subscales. Socio-demographic and clinical data were collected. Statistical analyses included nonparametric tests, correlation analysis for validity, and Cronbach’s alpha for internal consistency. Results: Out of 85 participants, 81 were included. The FAQLQ-PF demonstrated excellent internal consistency (Cronbach’s α = 0.94). Validity evaluation indicated its ability to measure HRQOL in younger children. HRQOL in the Greek pediatric population was significantly correlated with the number of food allergies, symptoms, parental and child concerns, anxiety levels, and activity restrictions. However, sex and general health status were not significantly correlated with HRQOL. Conclusions: The Greek translation and validation of FAQLQ-PF provides insights into HRQOL among Greek children with food allergies. Factors such as anaphylactic reactions, epinephrine autoinjector usage, number of food allergies, and symptoms influenced HRQOL in this population

Assessment of the Empowering Leadership Questionnaire (ELQ) in paediatric nursing

Background Empowering leadership plays a crucial role in healthcare settings. To evaluate empowering leadership, a questionnaire (Empowering Leadership Questionnaire, ELQ) has been developed and validated in several working settings. However, the tool is not validated in paediatric nursing. Given the peculiar characteristics of the leadership in this context, this study addresses this gap by assessing the ELQ's properties in paediatric nursing and exploring its association with demographic and occupational factors. Methods The study was conducted in a large Italian hospital, inviting all nursing staff members from five paediatric units to participate. The anonymous self-reported ELQ questionnaire was administered online together with a perceived quality survey. Statistical analyses included non-parametric tests, correlation analysis and multiple linear regression. Giving the multiple construct structure, we used McDonald's omega total coefficient to estimate internal consistency. Results A total of 103 questionnaires were collected. The ELQ showed high internal consistency in all its five dimensions. Criterion validity compared with perceived quality of work of nurses showed significant correlation (r=0.35, p<0.001). An association between respondent age (p=0.002), job seniority (p=0.01) and ELQ scores was observed. Conclusion This study analysed for the first time the ELQ in paediatric nursing, underlying its functioning and utility in evaluating empowering leadership in this peculiar setting. Furthermore, the study findings suggest that fostering empowering leadership can benefit overall work quality and satisfaction in paediatric nursing

Phosphine Oxide Porous Organic Polymers Incorporating Cobalt(II) Ions: Synthesis, Characterization, and Investigation of H2Production

Suitably functionalized porous matrices represent versatile platforms to support well-dispersed catalytic centers. In the present study, porous organic polymers (POPs) containing phosphine oxide groups were fabricated to bind transition metals and to be investigated for potential electrocatalytic applications. Cross-linking of mono- and di-phosphine monomers with multiple phenyl substituents was subject to the Friedel-Crafts (F-C) reaction and the oxidation process, which generated phosphine oxide porous polymers with pore capacity up to 0.92 cm3/g and a surface area of about 990 m2/g. The formation of the R3P·BH3 borohydride adduct during synthesis allows to extend the library of phosphine-based monomeric entities when using FeCl3. The porous polymers were loaded with 0.8-4.2 w/w % of cobalt(II) and behaved as hydrogen evolution reaction (HER) catalysts with a Faradaic efficiency of up to 95% (5.81 × 10-5 mol H2 per 11.76 C) and a stable current density during repeated controlled potential experiments (CPE), even though with high overpotentials (0.53-0.68 V to reach a current density of 1 mA·cm-2). These studies open the way to the effectiveness of tailored phosphine oxide POPs produced through an inexpensive and ecofriendly iron-based catalyst and for the insertion of transition metals in a porous architecture, enabling electrochemically driven activation of small molecules

P-Type Silicon Strip Sensors for the new CMS Tracker at HL-LHC

The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. This paper describes the main measurement results and conclusions that motivated this decision

Test beam demonstration of silicon microstrip modules with transverse momentum discrimination for the future CMS tracking detector

A new CMS Tracker is under development for operation at the High Luminosity LHC from 2026 onwards. It includes an outer tracker based on dedicated modules that will reconstruct short track segments, called stubs, using spatially coincident clusters in two closely spaced silicon sensor layers. These modules allow the rejection of low transverse momentum track hits and reduce the data volume before transmission to the first level trigger. The inclusion of tracking information in the trigger decision is essential to limit the first level trigger accept rate. A customized front-end readout chip, the CMS Binary Chip (CBC), containing stub finding logic has been designed for this purpose. A prototype module, equipped with the CBC chip, has been constructed and operated for the first time in a 4 GeV/c positron beam at DESY. The behaviour of the stub finding was studied for different angles of beam incidence on a module, which allows an estimate of the sensitivity to transverse momentum within the future CMS detector. A sharp transverse momentum threshold around 2 GeV/c was demonstrated, which meets the requirement to reject a large fraction of low momentum tracks present in the LHC environment on-detector. This is the first realistic demonstration of a silicon tracking module that is able to select data, based on the particle's transverse momentum, for use in a first level trigger at the LHC . The results from this test are described here

Mechanical stability of the CMS strip tracker measured with a laser alignment system

Peer reviewe

Trapping in irradiated p-on-n silicon sensors at fluences anticipated at the HL-LHC outer tracker

The degradation of signal in silicon sensors is studied under conditions expected at the CERN High-Luminosity LHC. 200 $\mu$m thick n-type silicon sensors are irradiated with protons of different energies to fluences of up to $3 \cdot 10^{15}$ neq/cm$^2$. Pulsed red laser light with a wavelength of 672 nm is used to generate electron-hole pairs in the sensors. The induced signals are used to determine the charge collection efficiencies separately for electrons and holes drifting through the sensor. The effective trapping rates are extracted by comparing the results to simulation. The electric field is simulated using Synopsys device simulation assuming two effective defects. The generation and drift of charge carriers are simulated in an independent simulation based on PixelAV. The effective trapping rates are determined from the measured charge collection efficiencies and the simulated and measured time-resolved current pulses are compared. The effective trapping rates determined for both electrons and holes are about 50% smaller than those obtained using standard extrapolations of studies at low fluences and suggests an improved tracker performance over initial expectations

Size-Controlled Synthesis of Colloidal Gold Nanoparticles at Room Temperature Under the Influence of Glow Discharge

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV–visible absorption spectra (UV–vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV–vis, XPS and EDX results confirmed that Au3+ ions in HAuCl4 solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl4 solution. Moreover, the as-synthesized Au colloids (dav = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma