THE EFFECT OF TiO2 NANOPARTICLES (DOPED OR NOT WITH Ag, ENCAPSULATED OR NOT IN LYPOSOMES), ON THE SPLEEN ULTRASTRUCTURE IN Mus musculus SPECIES, EXPOSED AT A STRESS FACTOR X-RAYS

The present experiment was performed on young females of Mus musculus, 22-24 g each, intraperitoneal injected with a suspension of titanium dioxide (five injections of 0.5 ml each, one at two days, with 0.01% TiO2 or TiO2-Ag suspension). The TiO2 nanoparticles of anatase crystallization form, 10-20 nm size, wereconjugated or not with 1% Ag, encapsulated or not in lyposome. A day after the third injection, half of theanimals received a sublethal dose of X-rays (2.58 Gy; the stress factor). A day after the last injection, the animals were sacrificed through the section of thecarotid artery. Ultrastructural investigations were performed at the spleen level. The analysis of the ultrastructural features from the spleen level enabledthe following observations: the single action of the TiO2 or TiO2-Ag nanoparticles induced an inflammatory process, but in the presence of X-rays, they manifested a slight protective effect; the TiO2-Ag nanoparticles, encapsulated in liposome, manifested a strong radioprotective effect, but the endocapsulation process is not optimal and has to be improved; the presence of a protective effect at the spleen level can suggest that the TiO2-Ag nanoparticles can be used to enhance the organism resistance in case of carcinogenic treatment (in animal or in homo)

THE EFFECT OF RADIONUCLIDES AND HEAVY METALS ON THE ULTRASTRUCTURAL FEATURES OF LEAVES IN HELIANTHUS ANNUUS

The ultrastructural features of the leaf in mature plants of Helianthus annuus (during flowering), cultivated in three different areas: in normal culture (Floresti village, Cluj district) and in cultures on sites polluted with heavy metals and radionuclides: (a) near the power station Turceni and (b) on sterile waste dump in the Pedological Research Station of Rovinari (Gorj district), were analyzed. The soil analysis in the three sites showed a higher content in radionuclides and heavy metals, especially on the soil from Turceni, as compared to Control. The ultrastructural analysis pointed out the effect of the presence of high amounts of radionuclides and heavy metals, as well as the plant reaction: the parietal disposition of the heterochromatin in the nucleus in the shape of bodyguard, synthesis and accumulation of some substances (probably with antioxidant or chelating role) in vacuoles, which interacted with exogenous particles, a/

Antibody protection against long-term memory loss induced by monomeric c-reactive protein in a mouse model of dementia

Monomeric C-reactive protein (mCRP), the activated isoform of CRP, induces tissue damage in a range of inflammatory pathologies. Its detection in infarcted human brain tissue and its experimentally proven ability to promote dementia with Alzheimer’s disease (AD) traits at 4 weeks after intrahippocampal injection in mice have suggested that it may contribute to the development of AD after cerebrovascular injury. Here, we showed that a single hippocampal administration of mCRP in mice induced memory loss, lasting at least 6 months, along with neurodegenerative changes detected by increased levels of hyperphosphorylated tau protein and a decrease of the neuroplasticity marker Egr1. Furthermore, co-treatment with the monoclonal antibody 8C10 specific for mCRP showed that long-term memory loss and tau pathology were entirely avoided by early blockade of mCRP. Notably, 8C10 mitigated Egr1 decrease in the mouse hippocampus. 8C10 also protected against mCRP-induced inflammatory pathways in a microglial cell line, as shown by the prevention of increased generation of nitric oxide. Additional in vivo and in vitro neuroprotective testing with the anti-inflammatory agent TPPU, an inhibitor of the soluble epoxide hydrolase enzyme, confirmed the predominant involvement of neuroinflammatory processes in the dementia induced by mCRP. Therefore, locally deposited mCRP in the infarcted brain may be a novel biomarker for AD prognosis, and its antibody blockade opens up therapeutic opportunities for reducing post-stroke AD risk

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe:a multicentre, prospective observational study

Background: The PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice. Methods: Febrile children and controls were recruited on presentation to hospital in 9 European countries 2016–2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed. Findings: Of 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92–5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07–7.59), Group A streptococcus (OR 2.73, 95% CI 1.13–6.09) and E. coli (OR 2.7, 95% CI 1.02–6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11–0.46), influenza B (OR 0.12, 95% CI 0.02–0.37) and RSV (OR 0.16, 95% CI: 0.06–0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23–0.72) and EBV (OR 0.71, 95% CI 0.56–0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively. Interpretation: Most febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics. Funding: EU Horizon 2020 grant 668303.</p

NEDA—NEutron Detector Array

The NEutron Detector Array, NEDA, will form the next generation neutron detection system that has been designed to be operated in conjunction with γ-ray arrays, such as the tracking-array AGATA, to aid nuclear spectroscopy studies. NEDA has been designed to be a versatile device, with high-detection efficiency, excellent neutron-γ discrimination, and high rate capabilities. It will be employed in physics campaigns in order to maximise the scientific output, making use of the different stable and radioactive ion beams available in Europe. The first implementation of the neutron detector array NEDA with AGATA 1π was realised at GANIL. This manuscript reviews the various aspects of NEDA

The new neutron multiplicity filter NEDA and its first physics campaign with AGATA

A new neutron multiplicity filter NEDA, after a decade of design, R&D and construction, was employed in its first physics campaign with the AGATA spectrometer. Properties and performance of the array are discussed

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Photopyroelectric spectroscopy and calorimetry

In this tutorial, we present an overview of the development of the photopyroelectric (PPE) technique, from its beginnings in 1984, through to the present day. The tutorial is organized in five sections, exploring both theoretical and experimental aspects of PPE detection, as well as some important spectroscopic and calorimetric applications. In the “Introduction” section we present the fundamental basics of photothermal phenomena and the state-of-the-art of the photopyroelectric technique. In the “Theoretical aspects” section we describe some specific cases of experimental interest, with examples in both back and front detection configurations. Several mathematical expressions for the PPE signal in specific detection modes (combined back-front configurations and PPE-IRT methods) are also deduced. The “Instrumentation and experiment” section contains two sub-sections. The first describes several examples of set-ups used for both room temperature and temperature-controlled experiments. The second sub-section is dedicated to the configuration of detection cells and to the various sensor/sample assemblies that are currently used in spectroscopic and calorimetric experiments for both liquid and solid samples. The “Applications” section is in fact a collection of experimental results dedicated to the thermal characterization of a wide range of solid and liquid samples. At the end of this section we present some examples that have been selected to convey that the PPE technique is not only useful in the investigation of optical and thermal properties of a variety of condensed matter samples, but also to study physical and chemical processes such as molecular associations, food adulteration or phase transitions. In “Concluding remarks” we summarize the advantages of this technique in spectroscopic and calorimetric applications

Photothermoelectric (PTE) characterization of CuCrO2 and Cu4Sn7S16 thermoelectric materials

International audienceThe recently developed photothermoelectric (PTE) calorimetry was applied to measure the thermal parameters of CuCrO2 and Cu4Sn7S16 thermoelectric materials. Both back and front PTE detection configurations were combined to directly measure the thermal diffusivity and effusivity of the above-mentioned solid thermoelectrics. In the back configuration, CuCrO2 (Seebeck coefficient approximately + 1200 A mu V K-1) was used as a thermoelectric sensor and CuCrO2 and Cu4Sn7S16 as samples. In the front detection, both CuCrO2 and Cu4Sn7S16 (Seebeck coefficient approximately - 600 A mu V K-1) materials were alternatively used as sensors, the sample being in this case a thermally thick layer of silicone grease. The proposed combination of configurations eliminates any possible results degeneracy because each fitting procedure involves only one fitting parameter. The results obtained by PTE investigations alpha (CuCrO2) = 1.19 x 10(-6) m(2) s(-1), alpha (Cu4Sn7S16) = 0.33 x 10(-6) m(2) s(-1) and e (CuCrO2) = 780 W s(1/2) m(-2) K-1, e (Cu4Sn7S16) = 1358 W s(1/2) m(-2) K-1 were validated by photopyroelectric (PPE) measurements