Influence of alkyl groups on the formation of softenable polysilsesquioxanes

Polysilsesquioxanes (PSQ) containing phenyl groups as substituents on the silicon atom can form transparent, hard and glassy materials at room temperature, which reversibly soften when heated above the glass transition temperature. Further increase in temperature leads to irreversible curing. With this property, polyphenylsilsesquioxanes can be assigned to the so-called melting gels. In contrast to the aromatic systems, polysilsesquioxanes with alkyl groups belonging to this class of materials are not known. To identify structural differences between aryl and alkyl systems, polyalkylsilsesquioxanes (RPSQs with R = methyl, ethyl, propyl, hexyl, octyl, decyl, dodecyl, hexadecyl, and octadecyl) were synthesised by a solvent-free, acid-catalysed hydrolysis and condensation reaction of alkyltrimethoxysilanes followed by thermal treatment at 300 °C under N2 atmosphere. The influence of the alkyl chain length on the structure built and the thermally initiated further condensation reactions were investigated via NMR, FTIR, TGA, DSC, SEC, and XRD. Depending on the alkyl chain length, the formation of highly crosslinked, insoluble systems (Me-PrPSQ), low molecular weight oligosilsesquioxanes in the form of cages (Hex-DecPSQ) to semicrystalline, lamellar layers (Dodec-OctadecPSQ) were detected. A low degree of condensation, inhibition of self-assembly and preferentially intermolecular condensation reactions were found to be crucial factors in the melting gel formation

Immunize the Public against Disinformation Campaigns: Developing a Framework for Analyzing the Macrosocial Effects of Prebunking Interventions

The rapid spread of disinformation through online environments challenges the development of suitable solution approaches. The scientific evaluation of various intervention strategies shows that until now, no magic bullet has been found that can overcome the problem in all relevant dimensions. Due to the effective impact at the individual level, research highlights the potential of prebunking interventions as a promising coping approach to achieve herd immunity to disinformation on a macrosocial level. Inside a detection system, prebunking interventions can curb the spread of disinformation campaigns early. The identification of turning points at which preventive intervention in (dis)information diffusion is necessary for implementation first requires an exploration of the effectiveness of the diffusion of prebunking interventions in social networks. We present a framework for analyzing the macrosocial effects and patterns of the effectiveness of prebunking interventions in the context of three different attack scenarios of stereotypical disinformation campaigns using agent-based modeling

Platinum free thermally curable siloxanes for optoelectronic application – synthesis and properties

Polysiloxanes for applications in the area of optical devices are usually based on two-component platinum catalysed cross-linked materials. Here we report the synthesis and properties of a novel one-component siloxane that can be thermally cured showing similar tailorable properties like commercially available encapsulation systems without using a noble metal catalyst. The pre-curing material is formed by an acid catalysed condensation reaction of trialkoxysilanes (TAS), dialkoxysilanes (DAS) and alkoxy-terminated polysiloxanes. NMR analysis of the formed polymeric compounds reveal that the materials are partially cross-linked gels. The obtained compounds can be thermally cured and consolidated at temperatures between 160 and 200 °C. Depending on the composition a tuneable hardness in between 50–90 Shore A, refractive indices of 1.494–1.505, as well as high temperature stabilities up to 443 °C were obtained. The high thermal- and photostability, the high transparency, as well as the tailorable refractive index makes these materials to ideal systems for optoelectronic applications. Investigations under increased temperatures and high-density illumination reveal that the material can withstand conditions, which are typical for high-performance light emitting diodes (LED)

Multiple Occurrences of a 168-Nucleotide Deletion in SARS-CoV-2 ORF8, Unnoticed by Standard Amplicon Sequencing and Variant Calling Pipelines

Brandt D, Simunovic M, Busche T, et al. Multiple Occurrences of a 168-Nucleotide Deletion in SARS-CoV-2 ORF8, Unnoticed by Standard Amplicon Sequencing and Variant Calling Pipelines. Viruses. 2021;13(9): 1870.Genomic surveillance of the SARS-CoV-2 pandemic is crucial and mainly achieved by amplicon sequencing protocols. Overlapping tiled-amplicons are generated to establish contiguous SARS-CoV-2 genome sequences, which enable the precise resolution of infection chains and outbreaks. We investigated a SARS-CoV-2 outbreak in a local hospital and used nanopore sequencing with a modified ARTIC protocol employing 1200 bp long amplicons. We detected a long deletion of 168 nucleotides in the ORF8 gene in 76 samples from the hospital outbreak. This deletion is difficult to identify with the classical amplicon sequencing procedures since it removes two amplicon primer-binding sites. We analyzed public SARS-CoV-2 sequences and sequencing read data from ENA and identified the same deletion in over 100 genomes belonging to different lineages of SARS-CoV-2, pointing to a mutation hotspot or to positive selection. In almost all cases, the deletion was not represented in the virus genome sequence after consensus building. Additionally, further database searches point to other deletions in the ORF8 coding region that have never been reported by the standard data analysis pipelines. These findings and the fact that ORF8 is especially prone to deletions, make a clear case for the urgent necessity of public availability of the raw data for this and other large deletions that might change the physiology of the virus towards endemism

Multiple Occurrences of a 168-Nucleotide Deletion in SARS-CoV-2 ORF8, Unnoticed by Standard Amplicon Sequencing and Variant Calling Pipelines

Genomic surveillance of the SARS-CoV-2 pandemic is crucial and mainly achieved by amplicon sequencing protocols. Overlapping tiled-amplicons are generated to establish contiguous SARS-CoV-2 genome sequences, which enable the precise resolution of infection chains and outbreaks. We investigated a SARS-CoV-2 outbreak in a local hospital and used nanopore sequencing with a modified ARTIC protocol employing 1200 bp long amplicons. We detected a long deletion of 168 nucleotides in the ORF8 gene in 76 samples from the hospital outbreak. This deletion is difficult to identify with the classical amplicon sequencing procedures since it removes two amplicon primer-binding sites. We analyzed public SARS-CoV-2 sequences and sequencing read data from ENA and identified the same deletion in over 100 genomes belonging to different lineages of SARS-CoV-2, pointing to a mutation hotspot or to positive selection. In almost all cases, the deletion was not represented in the virus genome sequence after consensus building. Additionally, further database searches point to other deletions in the ORF8 coding region that have never been reported by the standard data analysis pipelines. These findings and the fact that ORF8 is especially prone to deletions, make a clear case for the urgent necessity of public availability of the raw data for this and other large deletions that might change the physiology of the virus towards endemism

Multicenter Prospective Cohort Study of the Patient-Reported Outcome Measures PRO-CTCAE and CAT EORTC QLQ-C30 in Major Abdominal Cancer Surgery (PATRONUS): A Student-Initiated German Medical Audit (SIGMA) Study

Background!#!The patient-reported outcomes (PRO) version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) and the computerized adaptive testing (CAT) version of the EORTC quality-of-life questionnaire QLQ-C30 have been proposed as new PRO measures in oncology; however, their implementation in patients undergoing cancer surgery has not yet been evaluated.!##!Methods!#!Patients undergoing elective abdominal cancer surgery were enrolled in a prospective multicenter study, and postoperative complications were recorded according to the Dindo-Clavien classification. Patients reported PRO data using the CAT EORTC QLQ-C30 and the PRO-CTCAE to measure 12 core cancer symptoms. Patients were followed-up for 6 months postoperatively. The study was carried out by medical students of the CHIR-Net SIGMA study network.!##!Results!#!Data of 303 patients were obtained and analyzed across 15 sites. PRO-CTCAE symptoms 'poor appetite', 'fatigue', 'exhaustion' and 'sleeping problems' increased after surgery and climaxed 10-30 days postoperatively. At 3-6 months postoperatively, no PRO-CTCAE symptom differed significantly to baseline. Patients reported higher 'social functioning' (p = 0.021) and overall quality-of-life scores (p < 0.05) 6 months after cancer surgery compared with the baseline level. There was a lack of correlation between postoperative complications or death and any of the PRO items evaluated. Feasibility endpoints for student-led research were met.!##!Conclusion!#!The two novel PRO questionnaires were successfully applied in surgical oncology. Postoperative complications do not affect health-reported quality-of-life or common cancer symptoms following major cancer surgery. The feasibility of student-led multicenter clinical research was demonstrated, but might be enhanced by improved student training