UV and EUV Instruments

We describe telescopes and instruments that were developed and used for astronomical research in the ultraviolet (UV) and extreme ultraviolet (EUV) regions of the electromagnetic spectrum. The wavelength ranges covered by these bands are not uniquely defined. We use the following convention here: The EUV and UV span the regions ~100-912 and 912-3000 Angstroem respectively. The limitation between both ranges is a natural choice, because the hydrogen Lyman absorption edge is located at 912 Angstroem. At smaller wavelengths, astronomical sources are strongly absorbed by the interstellar medium. It also marks a technical limit, because telescopes and instruments are of different design. In the EUV range, the technology is strongly related to that utilized in X-ray astronomy, while in the UV range the instruments in many cases have their roots in optical astronomy. We will, therefore, describe the UV and EUV instruments in appropriate conciseness and refer to the respective chapters of this volume for more technical details.Comment: To appear in: Landolt-Boernstein, New Series VI/4A, Astronomy, Astrophysics, and Cosmology; Instruments and Methods, ed. J.E. Truemper, Springer-Verlag, Berlin, 201

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Crystallization and preliminary x-ray diffraction analysis of L-threonine dehydrogenase (TDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis

The enzyme L-threonine dehydrogenase catalyses the NAD(+)-dependent conversion of L-threonine to 2-amino-3-ketobutyrate, which is the first reaction of a two-step biochemical pathway involved in the metabolism of threonine to glycine. Here, the crystallization and preliminary crystallographic analysis of L-threonine dehydrogenase (Tk-TDH) from the hyperthermophilic organism Thermococcus kodakaraensis KOD1 is reported. This threonine dehydrogenase consists of 350 amino acids, with a molecular weight of 38 kDa, and was prepared using an Escherichia coli expression system. The purified native protein was crystallized using the hanging-drop vapour-diffusion method and crystals grew in the tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 124.5, c = 271.1 A. Diffraction data were collected to 2.6 A resolution and preliminary analysis indicates that there are four molecules in the asymmetric unit of the crystal

A Study on the Perception of Haptics in Surgical Simulation

Physically accurate modeling of human soft-tissue is an active research area in surgical simulation. The challenge is compounded by the need for real-time feedback. A good understanding of human haptic interaction can facilitate tissue modeling research, as achieving accuracy beyond perception may be counterproductive. This paper studies human sensitivity to haptic feedback. Specifically, the ability of individuals to consistently recall specific haptic experience, and their ability to perceive latency in haptic feedback. Results suggest that individual performance varies widely, and that this ability is not correlated with clinical experience. A surprisin

Structure and function of the l-threonine dehydrogenase (TkTDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis

The X-ray structure of the holo-form of l-threonine dehydrogenase (TDH) from Thermococcus kodakaraensis (TkTDH) has been determined at 2.4 Å resolution. TDH catalyses the NAD+-dependent oxidation of l-threonine to 2-amino-3-ketobutyrate, and is one of the first enzymes in this family to be solved by X-ray crystallography. The enzyme is a homo-tetramer, each monomer consisting of 350 amino acids that form two domains; a catalytic domain and a nicotinamide co-factor (NAD+)-binding domain, which contains an ?/? Rossmann fold motif. An extended twelve-stranded ?-sheet is formed by the association of pairs of monomers in the tetramer. TkTDH shows strong overall structural similarity to TDHs from thermophiles and alcohol dehydrogenases (ADH) from lower life forms, despite low sequence homology, exhibiting the same overall fold of the monomer and assembly of the tetramer. The structure reveals the binding site of the essential co-factor NAD+ which is present in all subunits. Docking studies suggest a mode of interaction of TDH with 2-amino-3-ketobutyrate CoA ligase, the subsequent enzyme in the pathway for conversion of threonine to glycine. TDH is known to form a stable functional complex with 2-amino-3-ketobutyrate ligase, most probably to shield an unstable intermediate