Disentangling the Photodissociation Dynamics of the HF+ Molecular Radical via Kinetic-Energy-Release-Resolved F 1s Core Excitation and Ionization

The F 1s core level photoionization of the ionic molecular radical HF⁺ has been studied using the photon-ion merged-beams technique at a synchrotron radiation source. Upon analyzing kinetic energy release (KER) dependent photoion yield spectra, complex ultrafast dissociation dynamics of the F 1s core hole excited σ* state can be revealed. By means of configuration-interaction electronic structure calculations of the excited molecular potential energy curves, this complex process can be attributed to a spin-dependent dissociation of the excited σ* biradical state.

Teaching and learning in a multilingual Europe: findings from a cross-European study

School classrooms within the EU are multilingual learning environments. The diversity of pupils in classrooms raises significant challenges for teachers, but to date, there are no data from large-scale surveys that compare views within and across European countries. A bespoke questionnaire was designed to examine views of current classroom learning environments with respect to the multilingualism. The questionnaire was piloted and subsequently completed by 2792 teachers across different European countries. Eleven countries provided sufficient data for analyses. Results from structural equation modelling showed that teachers’ attitudes could be reliably measured across Europe with the use of carefully devised questionnaire, whose loading and factor structure remained invariant across countries. Teachers’ views about multilingualism were most challenged by the numbers of children in their classes, not the percentage of multilingual pupils in the class. Countries differed in how they perceived multilingualism, with their differences leading to distinctive country clusters. Gender and education level (elementary vs. secondary) differences were also observed irrespective of country. These findings enhance our understanding of the role that the characteristics of teachers and their classrooms play in a multilingual setting across diverse European settings. The practical relevance of the results and new opportunities for teacher training are discussed.

Leaf application of chitosan and physiological evaluation of maize hybrids contrasting for drought tolerance under water restriction

Abstract It is a fact that the regions that cultivate the most maize crop do not have fully adequate technologies to measure productivity losses caused by irregularities in water availability. The objective of this study was to evaluate the physiological characteristics of maize hybrids tolerant (DKB 390) and sensitive (BRS 1030) to drought, at V5 growth stage and under water restriction, in order to understand the mechanisms involved in the induction of tolerance to drought by chitosan in contrasting maize genotypes. Plants were cultivated in pots at a greenhouse, and chitosan 100 ppm was applied by leaf spraying. The water restriction was imposed for 10 days and then leaf gaseous exchange and chlorophyll fluorescence were evaluated. The tolerant hybrid (DKB 390) showed higher photosynthesis, stomatal conductance, carboxylation efficiency, electron transport rate, and non-photochemical quenching when chitosan was used. Plants from tolerant genotype treated with chitosan were more tolerant to water stress because there were more responsive to the biopolymer.

AB1213 DIFFERENT IMMUNOSUPPRESSIVE REGIMENS WITH NO EFFECT ON INFLUENZA-LIKE ILLNESS

Background:

Autoimmune disease (AID) has been associated with increased risk of influenza and influenza-like illness (ILI) and its worse clinical outcomes complications.

Objectives:

We aimed to assess the influence and difference of several immunosuppressive (IS) treatments in the incidence of ILI, including glucocorticoids (GC), classic DMARDs and biologic DMARDs.

Methods:

We conducted a cross-sectional study in two autoimmune clinics. Patients were invited to answer a survey reporting ILI symptoms between October 2017 and March 2018. ILI definition was considered according to the European Center for Disease Control. Data regarding current IS, diagnostic, disease activity, comorbidities, and vaccination coverage were collected from electronic registry. Patients with history of cancer, HIV, IGIV treatment, or lack of information were excluded. Univariate and multivariate logistic regression analysis were used to access predictors of ILI.

Results:

We included 109 patients, with mean age 51 years and 81% female gender. The majority of patients had autoimmune arthropathy (n=54) or a connective tissue disease (n=44). Active disease was present in in 39% of patients. IS treatment was: GC 31%, classic DMARD 44%, biologic DMARD 28%. Vaccine coverage was 51%. Overall 41% reported ILI. We did not find any association between studied variables and ILI, including univariate and multivariate analysis. Univariate odds ratio calculation for IS treatment were: GC [OR 1,68 IC 0,7-3,8], classic DMARD [OR 1,03 IC 0,5-2,2], and biologic DMARD [OR 0,86 IC 0,4-2,0]. Comorbidity of pulmonary disease (n=8) may contribute to higher risk to ILI [OR 2,76 IC 0,8-10,0].

Conclusion:

There was no difference in risk of ILI within different IS treatment regimens, although GC may increase the risk. The study is limited by the subjectivity of the ILI survey and the small size of the sample. The stratification of influenza risk will help in designing better vaccine coverage strategies in this population.

References:

[1]Nakafero G, Grainge MJ, Myles PR, Mallen CD, Zhang W, Doherty M, Nguyen-Van-Tam JS, Abhishek A. Predictors and temporal trend of flu vaccination in auto-immune rheumatic diseases in the UK: a nationwide prospective cohort study. Rheumatology (Oxford). 2018 Oct 1;57(10):1726-1734.

[2]Danza A, Ruiz-Irastorza G. Infection risk in systemic lupus erythematosus patients: susceptibility factors and preventive strategies. Lupus. 2013 Oct;22(12):1286-94.

[3]McLean-Tooke A, Aldridge C, Waugh S, Spickett GP, Kay L. Methotrexate, rheumatoid arthritis and infection risk: what is the evidence? Rheumatology (Oxford). 2009 Aug;48(8):867-71.

[4]Lacaille D, Guh DP, Abrahamowicz M, Anis AH, Esdaile JM. Use of non biologic disease-modifying antirheumatic drugs and risk of infection in patients with rheumatoid arthritis. Arthritis Rheum. 2008 Aug 15;59(8):1074-81.

[5]Bernatsky S, Hudson M, Suissa S. Anti-rheumatic drug use and risk of serious infections in rheumatoid arthritis. Rheumatology (Oxford). 2007 Jul;46(7):1157-60.

[6]Doran MF, Crowson CS, Pond GR, O’Fallon WM, Gabriel SE. Predictors of infection in rheumatoid arthritis. Arthritis Rheum. 2002 Sep;46(9):2294-300.

[7]Fessler BJ. Infectious diseases in systemic lupus erythematosus: risk factors, management and prophylaxis. Best Pract Res Clin Rheumatol. 2002 Apr;16(2):281-91. Review.

[8]Singh JA, Wells GA, Christensen R, Tanjong Ghogomu E, Maxwell L, Macdonald JK, Adverse effects of biologics: a network meta-analysis and Cochrane overview. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD008794.

Acknowledgments:

None.

Disclosure of Interests:

None declared

Multiple Photodetachment of Carbon Anions via Single and Double Core-Hole Creation

We report on new measurements of m-fold photodetachment (m=2-5) of carbon anions via K-shell excitation and ionization. The experiments were carried out employing the photon-ion merged-beams technique at a synchrotron light source. While previous measurements were restricted to double detachment (m=2) and to just the lowest-energy K-shell resonance at about 282 eV, our absolute experimental m-fold detachment cross sections at photon energies of up to 1000 eV exhibit a wealth of new thresholds and resonances. We tentatively identify these features with the aid of detailed atomic-structure calculations. In particular, we find unambiguous evidence for fivefold detachment via double K-hole production.

Advances on assessing nanotoxicity in marine fish - the pros and cons of combining an ex vivo approach and histopathological analysis in gills

The need to overcome logistic and ethical limitations of in vivo nanotoxicity evaluation in marine organisms is essential, mostly when dealing with fish. It is well established that medium/solvent conditions affect dispersion and agglomeration of nanoparticles (NPs), which represents a constraint towards a solid and realistic toxicity appraisal. In this way the pros and cons of an ex vivo approach, using a simplified exposure medium (seawater) and addressing gills histopathology, were explored. The nanotoxic potential of environmentally realistic concentrations of titanium dioxide NPs (TiO₂ NPs) was also assessed, disclosing the morpho-functional effects on the gills and the possible uptake/elimination processes. Excised gills of the Senegalese sole (Solea senegalensis) were directly exposed in artificial seawater to 20 and 200 μg L^-1 TiO₂ NPs, for 2 h and 4 h. Semi-quantitative and quantitative histological analyses were applied. The normal morphology of the gill's epithelia was only slightly altered in the control, reflecting protective mechanisms against the artificiality of the experimental conditions, which, together with the absence of differences in the global histopathological index (I_h), corroborated that the gill's morpho-functional features were not compromised, thereby validating the proposed ex vivo approach. TiO₂ NPs induced moderate severity and dissemination of histopathological lesions. After 2 h, a series of compensatory mechanisms occurred in NP treatments, implying an efficient response of the innate defense system (increasing number of goblet cells) and effective osmoregulatory ability (chloride cells proliferation). After 4 h, gills revealed signs of recovery (normalization of the number of chloride and goblet cells; similar I_h), highlighting the tissue viability and effective elimination and/or neutralization of NPs. The uptake of the TiO₂ NPs seemed to be favored by the higher particle sizes. Overall, the proposed approach emerged as a high-throughput, reliable, accurate and ethically commendable methodology for nanotoxicity assessment in marine fish.

A histological evaluation of the surgical margins from human oral fibrous-epithelial lesions excised with CO2 laser, Diode laser, Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and cold scalpel

Background

We aim to evaluate the presence of histological artefacts in the surgical margins of human oral fibro-epithelial hyperplasias excised with lasers of different wavelengths, and also electrosurgical scalpel and cold scalpel. Moreover, we aim to determine if some of these instruments could impair the normal histological diagnosis of these lesions.

Material and Methods

We included 130 consecutive surgical samples of 80 females and 50 males (mean age of 53.82±16.55) with a histological diagnosis of an oral benign fibrous-epithelial hyperplasias. The samples were categorized into 6 groups according to the type of instrument used: CO2 laser group, diode laser group, Er:YAG laser group, Nd:YAG laser group, electrosurgical scalpel group and cold scalpel group. Histological instrument-induced changes were microscopic evaluated and related with clinical and pathological variables.

Results

The instrument with highest tissue damage extension (TDE) was the electrosurgical scalpel (1002.2µm±434.92), followed by diode laser (913.73 µm±322.45), Nd:YAG (899.83µm±327.75), CO2 laser (538.37µm±170.50), Er:YAG laser (166.47µm±123.85), and at last with fewer alterations the cold scalpel group (2.36µm±7.27) (P< 0.001). The most regular incision was observed in CO2 laser group, followed by Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and diode laser group with the less regular incision using cold scalpel as comparison (P< 0.001). A correlation was found between the incision score and TDE (P< 0.001). Regarding histological diagnosis, no case showed any limitation of diagnosis related with the use of any instrument evaluated.

Conclusions

Our results suggest that lasers can be used for the excision of oral benign fibrous-epithelial hyperplasias, without hispathological diagnosis limitations, as long as the physical properties of each laser are known and respected. Er:YAG laser have shown to be a laser with few tissue damage extension and with good incision regularity, been a possible instrument of choice for the surgical removal of these lesions.

Key words:CO2 laser, diode laser, Er:YAG laser, Nd:YAG laser, oral mucosa.

Respiratory signs, fever and lymphopenia in calves inoculated with Brazilian HoBi-like pestiviruses

Hobi-like viruses (HobiPeV) comprise a novel, recently classified species of bovine pestiviruses, originally identified in commercial fetal bovine serum of Brazilian origin and, subsequently, isolated from diseased animals in several countries. Although frequently isolated from clinical cases, most HobiPeV isolates failed to reproduce overt disease in cattle upon experimental inoculation. Herein, we describe the outcome of experimental infection of four to six months-old seronegative calves with two Brazilian HobiPeV isolates. Calves inoculated intranasally with isolate SV478/07 developed viremia between days 2 and 9 post-inoculation (pi) and shed virus in nasal secretions up to day 11pi. These animals presented hyperthermia (day 7 to 10-11 pi) and lymphopenia from days 4 to 8pi. Clinically, all four calves developed varied degrees of apathy, anorexia, mild to moderate respiratory signs (nasal secretion, hyperemia), ocular discharge and pasty diarrhea in the days following virus inoculation. In contrast, calves inoculated with isolate SV757/15 presented only hyperthermia (days 3 to 10-11 pi) and lymphopenia (days 4-8 pi), without other apparent clinical signs. In these animals, viremia was detected up to day 9 pi and virus shedding in nasal secretions lasted up to day 12-14 pi. Both groups seroconverted to the inoculated viruses, developing virus neutralizing (VN) titers from 320 to 5120 at day 28pi. These results extend previous findings that experimental infections of calves with HobiPeV are predominantly mild, yet they also indicate that field isolates may differ in their ability to cause disease in susceptible animals.