Characterization of a Structural Intermediate of Flavivirus Membrane Fusion

Viral membrane fusion proceeds through a sequence of steps that are driven by triggered conformational changes of viral envelope glycoproteins, so-called fusion proteins. Although high-resolution structural snapshots of viral fusion proteins in their prefusion and postfusion conformations are available, it has been difficult to define intermediate structures of the fusion pathway because of their transient nature. Flaviviruses possess a class II viral fusion protein (E) mediating fusion at acidic pH that is converted from a dimer to a trimer with a hairpin-like structure during the fusion process. Here we show for tick-borne encephalitis virus that exposure of virions to alkaline instead of acidic pH traps the particles in an intermediate conformation in which the E dimers dissociate and interact with target membranes via the fusion peptide without proceeding to the merger of the membranes. Further treatment to low pH, however, leads to fusion, suggesting that these monomers correspond to an as-yet-elusive intermediate required to convert the prefusion dimer into the postfusion trimer. Thus, the use of nonphysiological conditions allows a dissection of the flavivirus fusion process and the identification of two separate steps, in which membrane insertion of multiple copies of E monomers precedes the formation of hairpin-like trimers. This sequence of events provides important new insights for understanding the dynamic process of viral membrane fusion

Early Career Teacher Support - Pilot Report, EEF Evaluation

In order to provide timely feedback in the development of policy and programmes around the rollout of the Early Career Framework (DfE, 2019a), three pilot programmes were developed to investigate the promise, feasibility, and scalability of differing models for developing Early Career Teachers (ECTs), mentors, and induction leads. Two programmes were developed by Ambition Institute and a third by the Chartered College of Teaching. All aimed to provide mentors with the resources to deliver instructional coaching sessions to ECTs, coaching that uses expert teachers to deliver recurring, classroom-practice focused sessions, using observation and targeted feedback to develop practice. • Programme A (Ambition Institute) provided face-to-face training, a coaching guide, weekly online resources, and regular online coaching and support sessions to in-school mentors. School induction leads also received face-to-face training, designed to enable them to support mentors. Mentors used the programme to deliver instructional coaching to ECTs, either weekly or fortnightly. • Programme B (Ambition Institute) provided the same training as Programme A to mentors and school induction leads. In addition, this programme also delivered weekly online content and regular online support sessions directly to ECTs. The programme was also used to enable in-school mentors to deliver weekly or fortnightly instructional coaching sessions to ECTs. • Programme C (Chartered College of Teaching) provided online support to mentors, school induction leads, and ECTs. All received a selection of online modules providing weekly content to mentors and ECTs that were used to facilitate either weekly or fortnightly instructional coaching sessions, delivered by mentors to ECTs. The intention was not to undertake a comparative evaluation of these programmes but instead to evaluate the modes of support and delivery within them. Each programme was delivered to teachers teaching a variety of different year groups and subjects spanning primary and secondary education. Schools opted to receive one of these programmes. At the end of the evaluation there was a total of 98 schools across the pilot programmes: 50 primary schools, 45 secondary schools, and three all-through schools. The pilot evaluation was designed to run from June 2019 to July 2020. However, delivery and evaluation were modified due to the COVID-19 outbreak and this report covers the initial set-up period until February 2020. The pilot aimed to examine the evidence of promise, feasibility, and scalability of the programmes using a mixed methods approach using three waves of survey, 20 school case studies, online engagement data, observation of sessions, and evaluation of materials

Less sensitive oxygen-rich organic peroxides containing geminal hydroperoxy groups

Tetranitratoethane (C2H2N4O12), which has an oxygen content of 70.1% was synthesized by nitration of monomeric glyoxal using N2O5 and purified by sublimation. Single crystals could be grown from CH2Cl2/pentane and were used to determine the structure by X-ray diffraction. Several energetic parameters and values were also established

Less sensitive oxygen-rich organic peroxides containing geminal hydroperoxy groups

Tetranitratoethane (C2H2N4O12), which has an oxygen content of 70.1% was synthesized by nitration of monomeric glyoxal using N2O5 and purified by sublimation. Single crystals could be grown from CH2Cl2/pentane and were used to determine the structure by X-ray diffraction. Several energetic parameters and values were also established

Serological screening for tick-borne encephalitis virus in eight Norwegian herds of semi-domesticated reindeer

Tick-borne encephalitis virus (TBEV) is found in Ixodes ricinus ticks throughout the area where viable tick populations exist. In Norway, TBEV is found in I. ricinus from the south coast until Brønnøy municipality in Nordland County and the range of the vector is expanding due to changes in climate, vegetation, host animals and environmental conditions. TBEV might thus have the potential to establish in new areas when I. ricinus expand its geographical distribution. At present, there is little knowledge on the status of the virus in high-altitude areas of inland regions in Norway. It has previously been indicated that reindeer may be an important sentinel species and indicator of the spread of ticks and TBEV in high-altitude regions. In this study, 408 semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) from eight herds, from Tana in Troms and Finnmark County in northern Norway to Filefjell in Innlandet and Viken Counties in southern Norway, were screened for TBEV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA). We found 16 TBEV reactive reindeer samples by ELISA; however, these results could not be confirmed by the serum neutralization test (SNT). This could indicate that a flavivirusand not necessarily TBEV, may be circulating among Norwegian semi-domesticated reindeer. The results also indicate that TBEV was not enzootic in Norwegian semi-domesticated reindeer in 2013–2015. This knowledge is important as an information base for future TBEV and flavivirus surveillance in Norway

Ocean Acidification around the UK and Ireland

The average atmospheric carbon dioxide (CO2) concentration exceeded 414 parts per million (ppm) in 2021, a 49 % increase above pre-industrial levels, and increasing on average by 2.4 ppm per year over the past decade (Friedlingstein et al., 2022). This ongoing increase is primarily due to CO2 release by fossil fuel combustion, cement production and land-use change (mainly deforestation) (Friedlingstein et al., 2022; IPCC, 2021). Over a quarter of this annual anthropogenic CO2 emission dissolves into the Earth’s oceans each year (fossil fuel CO2 emissions = 9.5 ± 0.5 gigatonnes of carbon per year (Gt C yr-1, 1 Gt = one thousand million tonnes)), Land-use change emissions = 1.1 ± 0.7 Gt C yr-1, ocean uptake = 2.8 ± 0.4 Gt C yr-1; Friedlingstein et al., 2022). Once dissolved, the CO2 no longer influences the atmospheric heat budget, so this oceanic uptake mitigates human-driven warming and climate change. However, dissolved (or aqueous) CO2 undergoes a chemical reaction that releases hydrogen ions (H+), thereby decreasing the seawater’s pH (Figure 1). As pH declines, the carbonate ion concentration ([CO32−] also declines (Figure 1). The [CO32−] controls the saturation state (Ω) of calcium carbonate (CaCO3) minerals such as aragonite (ΩArag) and calcite (ΩCal), and indicates the ability of these minerals to precipitate (form) or dissolve. At Ω >1 water is supersaturated with Ca2+ and CO32− ions allowing CaCO3 minerals to form. When Ω <1, seawater is undersaturated with Ca2+ and CO32− ions and therefore any exposed CaCO3 minerals are prone to dissolution. These collective changes in marine carbonate chemistry are known as ‘ocean acidification’

Water dispersible microbicidal cellulose acetate phthalate film

BACKGROUND: Cellulose acetate phthalate (CAP) has been used for several decades in the pharmaceutical industry for enteric film coating of oral tablets and capsules. Micronized CAP, available commercially as "Aquateric" and containing additional ingredients required for micronization, used for tablet coating from water dispersions, was shown to adsorb and inactivate the human immunodeficiency virus (HIV-1), herpesviruses (HSV) and other sexually transmitted disease (STD) pathogens. Earlier studies indicate that a gel formulation of micronized CAP has a potential as a topical microbicide for prevention of STDs including the acquired immunodeficiency syndrome (AIDS). The objective of endeavors described here was to develop a water dispersible CAP film amenable to inexpensive industrial mass production. METHODS: CAP and hydroxypropyl cellulose (HPC) were dissolved in different organic solvent mixtures, poured into dishes, and the solvents evaporated. Graded quantities of a resulting selected film were mixed for 5 min at 37°C with HIV-1, HSV and other STD pathogens, respectively. Residual infectivity of the treated viruses and bacteria was determined. RESULTS: The prerequisites for producing CAP films which are soft, flexible and dispersible in water, resulting in smooth gels, are combining CAP with HPC (other cellulose derivatives are unsuitable), and casting from organic solvent mixtures containing ≈50 to ≈65% ethanol (EtOH). The films are ≈100 µ thick and have a textured surface with alternating protrusions and depressions revealed by scanning electron microscopy. The films, before complete conversion into a gel, rapidly inactivated HIV-1 and HSV and reduced the infectivity of non-viral STD pathogens >1,000-fold. CONCLUSIONS: Soft pliable CAP-HPC composite films can be generated by casting from organic solvent mixtures containing EtOH. The films rapidly reduce the infectivity of several STD pathogens, including HIV-1. They are converted into gels and thus do not have to be removed following application and use. In addition to their potential as topical microbicides, the films have promise for mucosal delivery of pharmaceuticals other than CAP

Kinder mit Kunstherzunterstützungssystemen im häuslichen Bereich: Ausbildungskonzept und Notfallalgorithmus für Rettungskräfte

Zusammenfassung: Einleitung: Miniaturisierte Herzunterstützungspumpen, sog. Kunstherzsysteme oder "ventricular assist devices" (VADs) bieten die Möglichkeit, diese Systeme im Kindesalter anzuwenden. Durch die lange Wartezeit auf ein geeignetes Spenderorgan sollte bei Kindern, unterstützt mit einem intrakorporealen VAD, die Entlassung nach Hause angestrebt werden. Schwerpunkte vor einem Spitalaustritt sind neben der adäquaten Schulung und Aufklärung des Patienten und deren Familie auch ein Ausbildungs- und Schulungskonzept für die lokalen Rettungskräfte und die Betreuungspersonen vor Ort. Methoden: Es wird ein auf die präklinische Versorgung abgestimmter Notfallalgorithmus für die Erstversorgung von VAD-Patienten vorgestellt sowie das gemeinsam erarbeitete Ausbildungskonzept der lokalen Rettungskräfte und des Kinderspitals Zürich. Schwerpunkte des Schulungsprogramms sind neben der theoretischen Einführung praktische Workshops, "cardiac arrest simulation training" (CAST) sowie die Erstellung eines genau definierten Alarmierungsplans unter Einbezug der lokalen ärztlichen Organisationsstrukturen und der Spezialisten des Kinderspitals. Schlussfolgerung: Die Besonderheiten bei der Versorgung von Kindern am VAD werden vorgestellt und diskutier

A Therapeutic Antibody against West Nile Virus Neutralizes Infection by Blocking Fusion within Endosomes

Defining the precise cellular mechanisms of neutralization by potently inhibitory antibodies is important for understanding how the immune system successfully limits viral infections. We recently described a potently inhibitory monoclonal antibody (MAb E16) against the envelope (E) protein of West Nile virus (WNV) that neutralizes infection even after virus has spread to the central nervous system. Herein, we define its mechanism of inhibition. E16 blocks infection primarily at a post-attachment step as antibody-opsonized WNV enters permissive cells but cannot escape from endocytic compartments. These cellular experiments suggest that E16 blocks the acid-catalyzed fusion step that is required for nucleocapsid entry into the cytoplasm. Indeed, E16 directly inhibits fusion of WNV with liposomes. Additionally, low-pH exposure of E16–WNV complexes in the absence of target membranes did not fully inactivate infectious virus, further suggesting that E16 prevents a structural transition required for fusion. Thus, a strongly neutralizing anti–WNV MAb with therapeutic potential is potently inhibitory because it blocks viral fusion and thereby promotes clearance by delivering virus to the lysosome for destruction