Study of glass formation in the Sb2O3-PbO-MnO ternary system

International audienceVitreous systems based on antimony oxide Sb2O3 have been investigated. The influence of MnO substitution on the mechanical and physical properties in the (80 − x)Sb2O3-20PbO-xMnO and (70 − x)Sb2O3-(30 − x)PbO-2xMnO systems has been studied. Vickers hardness, density, molar volume, Young modulus, glass temperature transition, infrared and UV transmission spectra depend on the MnO concentration. Crack analysis of the glass surface under indentor deformation shows the tenacity changes according to concentration of the MnO

Physico-chemical and sensory evaluation of virgin olive oils from several Algerian olive-growing regions

Olive cultivar diversity is rich in Algeria but most remain unexplored in terms of quality traits. This work aimed to evaluate the physicochemical and organoleptic quality of twenty olive oil samples belonging to four Algerian cultivars (Chemlal, Sigoise, Ronde de Miliana and Rougette de Mitidja) collected throughout the national territory. Physical-chemical and sensory results showed that 60% of the oils belong to the extra virgin category, while 40% were classified as “virgin olive oil”. The results of the principal component analysis (PCA) revealed a great variability in fatty acids composition between the samples depending on the cultivar and origin. Oleic acid was the most abundant and varied between 64.84 and 80.14%. Extra virgin olive oils with quality attributes are eligible for a label. Rougette de Mitidja, Ronde de Miliana and Sigoise from Oran showed great potential

Dynamic Covalent Chemistry Enables Reconfigurable All‐Polysaccharide Nanogels

International audienceDynamic covalent bonds are established upon molecular recognition of sugar derivatives by boronic acid molecules. These reversible links can be used in a cross-linking method to fabricate polymer-based responsive nanosystems. Herein, the design of the first dynamic nanogels made entirely of polysaccharides (PS) is reported. Based on PS chains alternately modified with phenyl boronic acid groups and sugar moieties, these colloids self-assemble in physiological conditions and combine the biocompatible nature of their PS backbone with the reconfiguration capacities of their cross-linking chemistry. These dynamic nanogels are easily prepared, stable for a long time, pH responsive, and efficiently internalized by cancer cells

Use of sea urchin spines with chitosan gel for biodegradable film production

In recent years, the film production from natural polymers has considerably increased in food industry as an alternative to the petroleum based synthetic films. Chitosan is one of the most preferred biopolymers for bio-based film production, due to its biocompatibility, biodegradability, antioxidant activity and antimicrobial properties. Because of its hydrophilic properties, chitosan based films dissolve in water, limiting its uses in industry, to overcome this problem; we mixed 200 and 400 mg of the sea urchin spine powder (SUSP) with 20 mL chitosan gel respectively, to obtain a hydrophobic film. The chitosan films prepared with 200 mg SUSP showed a rise in the degree of contact angle from 70.2° to 107° providing hydrophobicity properties. On the other hand, addition of 400 mg of SUSP to chitosan film resulted in a contact angle of 96.1°. Moreover, the antioxidant activity and thermal stability of the films were increased in the presence of SUSP. Fourier Transform Infrared Spectrophotometry results proved the interactions between chitosan and SUSP. Chitosan films have smooth surface while SUSP blended films have rough surface morphology. These results demonstrated that SUSP is needed to improve the properties of chitosan films for usage in food industry

High diversity and evidence for inter-species transmission in astroviruses surveyed from bats in Zibabwae

International audienceAstroviruses (AstVs) have been discovered in over 80 animal species including diverse bat species and avian species. A study on Astrovirus circulation and diversity in different insectivorous and frugivorous chiropteran species roosting in trees, caves and building basements was carried out at 11 different sites across Zimbabwe. Pooled and individual faecal sampling methods were used for this study, with collection dates ranging from June 2016 to July 2021. In two sites, Magweto and Chirundu, sampling was carried out at monthly intervals from August 2020 to July 2021. Astroviruses and bat mitochondrial genes were amplified using pan-AstVs and CytB /12S RNA PCR systems respectively. Phylogenetic analysis of the RdRp Astrovirus sequences revealed a high genetic diversity of astroviruses. All the bat astroviruses tested in this study clustered with the Mamastrovirus genus. Two distinct groups of amplified sequences were identified. One group was comprised of sequences isolated from Hipposideros, Rhinolophus and Eidolonhelvum spp. clustered with Human Astrovirus strains: HuAstV types1-6, HuAstV-MLB1-3 and HuAstV-VA-1. The second group comprising the majority of the sequences clustered with different strains of Bat AstVs. Results from the longitudinal study at Magweto and Chirundu showed an overall AstV prevalence of 13.7% and 10.4% respectively. Peaks of AstV infection at Chirundu coincided with the period when juveniles are 4-6 months old. By combining data from our previous work on Coronaviruses, we also anaylzed co-infection of bats with Coronaviruses and Astroviruses at Magweto and Chirundu sites for which the prevalence of co-infection was 2.6% and 3.5% respectively

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)