Advanced Nanocomposite Coatings of Fusion Bonded Epoxy Reinforced with Amino-Functionalized Nanoparticles for Applications in Underwater Oil Pipelines

The performance of fusion-bonded epoxy coatings can be improved through advanced composite coatings reinforced with nanomaterials. Hence, in this study a novel organic-inorganic nanocomposite finish was designed, synthesized, and characterized, achieved by adding γ-aminopropyltriethoxysilane modified silica nanoparticles produced via sol-gel process in epoxy-based powder. After the curing process of the coating reinforced with nanoparticles, the formation of a homogenous novel nanocomposite with the development of interfacial reactions between organic-inorganic and inorganic-inorganic components was observed. These hybrid nanostructures produced better integration between nanoparticles and epoxy matrix and improved mechanical properties that are expected to enhance the overall performance of the system against underwater corrosion

Antibiotic prescribing for respiratory tract complaints in Malta : a 1 year repeated cross-sectional surveillance study

Objectives: To determine the 1 year antibiotic prescribing patterns by GPs for acute respiratory tract complaints (aRTCs) in Malta. Methods: In this repeated cross-sectional surveillance study, GPs collected data for patients seen for aRTCs during a designated 1 week period each month, between May 2015 and April 2016. GPs received three text reminders during surveillance weeks and were contacted by phone at most four times during the year. GPs also received 3 monthly individual- and aggregate-level feedback reports on their antibiotic prescribing patterns. Descriptive statistics were used to examine patient, consultation and clinical characteristics, and to describe GPs’ prescribing patterns. Results: Participating GPs (n = 33) registered 4641 patients with an aRTC, of whom 2122 (45.7%) received an antibiotic prescription. The majority (99.6%) of antibiotics prescribed were broad-spectrum and the most commonly prescribed antibiotics were macrolides (35.5%), followed by penicillins with a β-lactamase inhibitor (33.2%) and second-generation cephalosporins (14.2%). Specifically, co-amoxiclav (33.2%), clarithromycin (19.6%), azithromycin (15.1%) and cefuroxime axetil (10.9%) represented 78.8% of all antibiotics prescribed. Patients with tonsillar exudate (99.1%), purulent sputum (84%), otorrhoea (78%), tender cervical nodes (74.4%) and fever (73.1%) received most antibiotics. The diagnoses that received the highest proportion of antibiotic treatment were tonsillitis (96.3%), otitis media (92.5%) and bronchitis (87.5%). Wide variation in the choice of antibiotic class by diagnosis was observed. Conclusions: GP antibiotic prescribing in Malta is high. The abundant use of broad-spectrum antibiotics, particularly macrolides, is of particular concern and indicates that antibiotics are being used inappropriately. Efforts must be made to improve GP awareness of appropriate antibiotic prescribing.peer-reviewe

Time-resolved single-cell RNA-seq using metabolic RNA labelling

Single-cell RNA sequencing offers snapshots of whole transcriptomes but obscures the temporal RNA dynamics. Here we present single-cell metabolically labeled new RNA tagging sequencing (scNT-seq), a method for massively parallel analysis of newly transcribed and pre-existing mRNAs from the same cell. This droplet microfluidics-based method enables high-throughput chemical conversion on barcoded beads, efficiently marking newly transcribed mRNAs with T-to-C substitutions. Using scNT-seq, we jointly profiled new and old transcriptomes in ~55,000 single cells. These data revealed time-resolved transcription factor activities and cell-state trajectories at the single-cell level in response to neuronal activation. We further determined rates of RNA biogenesis and decay to uncover RNA regulatory strategies during stepwise conversion between pluripotent and rare totipotent two-cell embryo (2C)-like stem cell states. Finally, integrating scNT-seq with genetic perturbation identifies DNA methylcytosine dioxygenase as an epigenetic barrier into the 2C-like cell state. Time-resolved single-cell transcriptomic analysis thus opens new lines of inquiry regarding cell-type-specific RNA regulatory mechanisms

Factors associated with antibiotic prescribing in patients with acute respiratory tract complaints in Malta : a 1-year repeated cross-sectional surveillance study

Objective: To identify factors that influence general practitioners’ (GPs’) oral antibiotic prescribing for acute respiratory tract complaints (aRTCs) in Malta. Design: Repeated, cross-sectional surveillance. Setting: Maltese general practice; both public health centres and private GP clinics. Participants: 30 GPs registered on the Malta Medical Council’s Specialist Register and 3 GP trainees registered data of 4831 patients of all ages suffering from any aRTC. Data were collected monthly between May 2015 and April 2016 during predetermined 1-week periods. Outcome measures: The outcome of interest was antibiotic prescription (yes/no), defined as an oral antibiotic prescription issued for an aRTC during an in-person consultation, irrespective of the number of antibiotics given. The association between GP, practice and consultation-level factors, patient sociodemographic factors and patient health status factors, and antibiotic prescription was investigated. Results: The antibiotic prescription rate was 45.0%. Independent factors positively associated with antibiotic prescribing included female GP sex (OR 2.3, 95% CI 1.22 to 4.26), GP age with GPs ≥60 being the most likely (OR 34.7, 95% CI 14.14 to 84.98), patient age with patients ≥65 being the most likely (OR 2.3, 95% CI 1.71 to 3.18), number of signs and/or symptoms with patients having ≥4 being the most likely (OR 9.6, 95% CI 5.78 to 15.99), fever (OR 2.6, 95% CI 2.08 to 3.26), productive cough (OR 1.3, 95% CI 1.03 to 1.61), otalgia (OR 1.3, 95% CI 1.01 to 1.76), tender cervical nodes (OR 2.2, 95% CI 1.57 to 3.05), regular clients (OR 1.3, 95% CI 1.05 to 1.66), antibiotic requests (OR 4.8, 95% CI 2.52 to 8.99) and smoking (OR 1.4, 95% CI 1.13 to 1.71). Conversely, patients with non-productive cough (OR 0.3, 95% CI 0.26 to 0.41), sore throat (OR 0.6, 95% CI 0.53 to 0.78), rhinorrhoea (OR 0.3, 95% CI 0.23 to 0.36) or dyspnoea (OR 0.6, 95% CI 0.41 to 0.83) were less likely to receive an antibiotic prescription. Conclusion: Antibiotic prescribing for aRTCs was high and influenced by a number of factors. Potentially inappropriate prescribing in primary care can be addressed through multifaceted interventions addressing modifiable factors associated with prescription.peer-reviewe

Targeting Extracellular Domains D4 and D7 of Vascular Endothelial Growth Factor Receptor 2 Reveals Allosteric Receptor Regulatory Sites

Vascular endothelial growth factors (VEGFs) activate three receptor tyrosine kinases, VEGFR-1, -2, and -3, which regulate angiogenic and lymphangiogenic signaling. VEGFR-2 is the most prominent receptor in angiogenic signaling by VEGF ligands. The extracellular part of VEGF receptors consists of seven immunoglobulin homology domains (Ig domains). Earlier studies showed that domains 2 and 3 (D23) mediate ligand binding, while structural analysis of dimeric ligand/receptor complexes by electron microscopy and small-angle solution scattering revealed additional homotypic contacts in membrane-proximal Ig domains D4 and D7. Here we show that D4 and D7 are indispensable for receptor signaling. To confirm the essential role of these domains in signaling, we isolated VEGFR-2-inhibitory “designed ankyrin repeat proteins” (DARPins) that interact with D23, D4, or D7. DARPins that interact with D23 inhibited ligand binding, receptor dimerization, and receptor kinase activation, while DARPins specific for D4 or D7 did not prevent ligand binding or receptor dimerization but effectively blocked receptor signaling and functional output. These data show that D4 and D7 allosterically regulate VEGFR-2 activity. We propose that these extracellular-domain-specific DARPins represent a novel generation of receptor-inhibitory drugs for in vivo applications such as targeting of VEGFRs in medical diagnostics and for treating vascular pathologies

Imprinted antibody responses against SARS-CoV-2 Omicron sublineages

SARS-CoV-2 Omicron sublineages carry distinct spike mutations and represent an antigenic shift resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters result in potent plasma neutralizing activity against Omicron BA.1 and BA.2 and that breakthrough infections, but not vaccination-only, induce neutralizing activity in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1 and BA.2 receptor-binding domains whereas Omicron primary infections elicit B cells of narrow specificity. While most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant antibody, that is unaffected by any Omicron lineage spike mutations and is a strong candidate for clinical development

Maturation of SARS-CoV-2 Spike-specific memory B cells drives resilience to viral escape

SUMMARYMemory B cells (MBCs) generate rapid antibody responses upon secondary encounter with a pathogen. Here, we investigated the kinetics, avidity and cross-reactivity of serum antibodies and MBCs in 155 SARS-CoV-2 infected and vaccinated individuals over a 16-month timeframe. SARS-CoV-2-specific MBCs and serum antibodies reached steady-state titers with comparable kinetics in infected and vaccinated individuals. Whereas MBCs of infected individuals targeted both pre- and postfusion Spike (S), most vaccine-elicited MBCs were specific for prefusion S, consistent with the use of prefusion-stabilized S in mRNA vaccines. Furthermore, a large fraction of MBCs recognizing postfusion S cross-reacted with human betacoronaviruses. The avidity of MBC-derived and serum antibodies increased over time resulting in enhanced resilience to viral escape by SARS-CoV-2 variants, including Omicron BA.1 and BA.2 sub-lineages, albeit only partially for BA.4 and BA.5 sublineages. Overall, the maturation of high-affinity and broadly-reactive MBCs provides the basis for effective recall responses to future SARS-CoV-2 variants

Imprinted antibody responses against SARS-CoV-2 Omicron sublineages

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant–neutralizing antibody that is a strong candidate for clinical development

Identification of a novel proinsulin-associated SNP and demonstration that proinsulin is unlikely to be a causal factor in subclinical vascular remodelling using Mendelian randomisation

Background and aims Increased proinsulin relative to insulin levels have been associated with subclinical atherosclerosis (measured by carotid intima-media thickness (cIMT)) and are predictive of future cardiovascular disease (CVD), independently of established risk factors. The mechanisms linking proinsulin to atherosclerosis and CVD are unclear. A genome-wide meta-analysis has identified nine loci associated with circulating proinsulin levels. Using proinsulin-associated SNPs, we set out to use a Mendelian randomisation approach to test the hypothesis that proinsulin plays a causal role in subclinical vascular remodelling. Methods We studied the high CVD-risk IMPROVE cohort (n = 3345), which has detailed biochemical phenotyping and repeated, state-of-the-art, high-resolution carotid ultrasound examinations. Genotyping was performed using Illumina Cardio-Metabo and Immuno arrays, which include reported proinsulin-associated loci. Participants with type 2 diabetes (n = 904) were omitted from the analysis. Linear regression was used to identify proinsulin-associated genetic variants. Results We identified a proinsulin locus on chromosome 15 (rs8029765) and replicated it in data from 20,003 additional individuals. An 11-SNP score, including the previously identified and the chromosome 15 proinsulin-associated loci, was significantly and negatively associated with baseline IMTmean and IMTmax (the primary cIMT phenotypes) but not with progression measures. However, MR-Eggers refuted any significant effect of the proinsulin-associated 11-SNP score, and a non-pleiotropic SNP score of three variants (including rs8029765) demonstrated no effect on baseline or progression cIMT measures. Conclusions We identified a novel proinsulin-associated locus and demonstrated that whilst proinsulin levels are associated with cIMT measures, proinsulin per se is unlikely to have a causative effect on cIMT