Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Glas och trä i samverkan - innovativa byggprodukter med mervärde : energi och miljö

Glas är en viktig del av våra byggnader. Utan kontakt med omgivningen trivs vi inte inomhus! Tidigare har glaset varit en stor källa till värmeförluster och i de första passivhusen användes små fönster. En intressant frågeställning var därmed om man kunde ha projektets bärande glaskonstruktion i ett passivhus. l projektet har tre olika prototyper för byggprodukter i glas och trä konstruerats och testats på olika sätt, främst ur hållfasthetssynpunkt Protoyperna har limmats ihop och av de testade limmerna visade det sig att ett akrylatlim hade den bäst prestandan i sammanhanget. Den väggprototyp som togs fram har använts som underlag för energiberäkn ingarna. För att få så bra energiprestanda som möjligt infogades en isolerruta och energibeläggningar i det konstruerade väggelementet Energiberäkningar både med Isover Energi3 och DEROB-LTH gjordes på ett friliggande enplanshus konstruerat för att kunna uppnå passivhusprestanda. Resultat från beräkningar med bara bra treglas isolerrutor i huset jämfördes med att använda två olika väggele­mentet med motsvarande glasyta. Yärmegenomgångskoefficienten, U-värdet, för väggelementet beräknades med hjälp av programmet U-norm. När andelen glas som procent av golvarean ökades från 12 till 16% ökade inte energiför­brukningen för något fall. Därefter började energiförbrukningen att öka för treglasfönstret och för det sämre väggelementet. För det bättre väggelementet kom inte ökningen förrän glasarean motsvarade 21% av golvytan. För att uppfylla passivhusrekommendationen för den specifika energiförbrukningen krävdes det att det bättre väggelementet användes och att hälften av varmvattnet värmdes via solen samt att rumstemperaturen inte fick överstiga 20°C. Det bör därmed kunna gå att nå passivhusnivån men det ställs stora krav på konstruktion, design och inte minst brukaren. Det blir för varmt inne under sommarhalvåret med alla tre konstruktionerna trots att det bättre väggelementet har en solskyddsbeläggning. Ett takutsprång på 1,5 meter minskar tiden då temperaturen överstiger 26 °C men inte tillräckligt mycket för att nå ner till rekommendationen på maximalt 10% av sommarhalvåret. En solskyddsbeläggning räcker därmed inte utan det krävs ytterligare solskydd. Beräkningar visar att t. ex. användning av en exteriör solskyddsväv eller ett elektrokromt belagt glas från Sage löser problemet. Med DEROB-LTH gjordes även beräkningar på ett förslag till en stationsbyggnad över järnvägsspåret i Växjö. Även här blir det varmt på sommaren. Används kylning för att inte temperaturen ska överskrida 30°C ökar energi förbrukningen med mellan 0,3-3%o. Med ett extra solskydd som en elektrokrom applikation eller extern väv behövs ingen kylning alls och temperaturer över 26°C uppträder mindre än 1% av tiden. Två hela väggelement byggdes där det ena elementet innehöll en energisparbeläggning i isolerrutan men inte den andra. Inga fler beläggningar användes och det var luft i isoler­rutorna. Dessa två provades i en hotbox. Den bästa av de två provade väggelementen har ett något sämre U-värde än den sämre av de två beräknade väggelementen och visar att detta är en fullt real iserbar konstruktion. Med hjälp av spänningsmäta ren, SCA LP, följdes spänningarna i glaset i den bärande del en av ett väggelement under en belastningsprovning med stigande vertikal linjelast upp till 80 kN. Resultaten i glasskivans mittpunkt följer ökningen av pålagd last väl och är ett smidigt sätt att kontrollera spänningar i en konstruktion på. Vid mätning av isolerrutan på ett väggelementen monterat i hotboxen och på ett element som stod fritt erhölls likartade spänningar. Resultaten från energiberäkningarna användes vid en LCA för det beräknade friliggande enplanshuset. Största påverkan på miljön har brukarfasen som utgör 94-95% av förbrukad primärenergi. Den lägre procentsatsen erhölls för väggelementet och den högre för treglasfönster med trä och aluminiumram. Även CO2 utsläppen blir något lägre...Glafo-rapport 2012:P80015. ISBN 978-91-633-9930-5.</p

Lead uptake increases drought tolerance of wild type and transgenic poplar (Populus tremula x P. alba) overexpressing gsh 1

Growth and development of plants largely depends on their adaptation ability in a changing climate. This is particularly true on heavy metal contaminated soils, but the interaction of heavy metal stress and climate on plant performance has not been intensively investigated. The aim of the present study was to elucidate if transgenic poplars (Populus tremula x P. alba) with enhanced glutathione content possess an enhanced tolerance to drought and lead (Pb) exposure (single and in combination) and if they are good candidates for phytoremediation of Pb contaminated soil. Lead exposure reduced growth and biomass accumulation only in above-ground tissue of wild type poplar, although most of lead accumulated in the roots. Drought caused a decline of the water content rather than reduced biomass production, while Pb counteracted this decline in the combined exposure. Apparently, metals such as Pb possess a protective function against drought, because they interact with abscisic acid dependent stomatal closure. Lead exposure decreased while drought increased glutathione content in leaves of both plant types. Lead accumulation was higher in the roots of transgenic plants, presumably as a result of chelation by glutathione. Water deprivation enhanced Pb accumulation in the roots, but Pb was subject to leakage out of the roots after re -watering. Transgenic plants showed better adaptation under mild drought plus Pb exposure partially due to improved glutathione synthesis. However, the transgenic plants cannot be considered as a good candidate for phytoremediation of Pb, due to its small translocation to the shoots and its leakage out of the roots upon re-watering

Glass, timber and adhesive joints – Innovative load bearing building components

Structural glass-timber composite beams and shear wall elements were investigated in terms of their mechanical behaviour, energy performance and their LCA performance. The load bearing components were manufactured using annealed float glass which was adhesively bonded to the timber with different adhesives. The results show, among other things, that is is possible to join the two materials glass and timber and obtaining a non-brittle failure of the beams. The shear wall elements have the potential of being used as stabilising elements and load bearing walls in buildings of up to 4 storeys height. It is possible to combine glass and timber in a load bearing shear wall without loss of energy performance of a building or without loosing LCA performance. In addition to these benefits, the timber glass composite wall has, of course the benefit of being transparent