Trophic status of Chlamydomonas reinhardtii influences the impact of iron deficiency on photosynthesis

To investigate the impact of iron deficiency on bioenergetic pathways in Chlamydomonas, we compared growth rates, iron content, and photosynthetic parameters systematically in acetate versus CO2-grown cells. Acetate-grown cells have, predictably (2-fold) greater abundance of respiration components but also, counter-intuitively, more chlorophyll on a per cell basis. We found that phototrophic cells are less impacted by iron deficiency and this correlates with their higher iron content on a per cell basis, suggesting a greater capacity/ability for iron assimilation in this metabolic state. Phototrophic cells maintain both photosynthetic and respiratory function and their associated Fe-containing proteins in conditions where heterotrophic cells lose photosynthetic capacity and have reduced oxygen evolution activity. Maintenance of NPQ capacity might contribute to protection of the photosynthetic apparatus in iron-limited phototrophic cells. Acetate-grown iron-limited cells maintain high growth rates by suppressing photosynthesis but increasing instead respiration. These cells are also able to maintain a reduced plastoquinone pool

Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials.

BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Aging as a predictor of nursing workload in Intensive Care Unit: results from a Brazilian Sample

OBJECTIVE Verify if aging is an independent predictor of NW in ICU, according to age groups, and its predictive value as a determinant of NW in ICU. METHODS Study was conducted from 2012 to 2016. A convenience sample composed by patients (age ≥ 18) admitted to nine ICU belonging to a Brazilian hospital, was analyzed. Age was assumed as an independent variable and NW (measured by the Nursing Activities Score - NAS) as dependent. Linear regression model and ROC curve were used for the analysis. RESULTS 890 participants (361 older people), mostly males (58.1%). The mean NAS score was higher among older participants in comparison to adults (p=0.004) but not within categories of aging (p=0.697). Age was responsible for 0.6% of NAS score. Each year of age increases NAS score in 0.081 points (p=0.015). However, age was not a good predictor of NAS score (AUC = 0.394; p=0.320). CONCLUSION The care of older people in ICU is associated with an increase in NW, compared to adults. Aging can be considered an associated factor but not a good predictor of NW in ICU.OBJETIVO Verificar si el envejecimiento es un predictor independiente de la Carga de Trabajo de Enfermería (CTE) en la Unidad de Cuidados Intensivos (UCI), según grupos etarios y su valor predictivo como determinante de la CTE en la UCI. MÉTODOS Se analizó una muestra de conveniencia compuesta por pacientes (edad ≥ 18) ingresados en nueve UCI pertenecientes a un hospital brasileño. La edad se asumió como variable independiente y como variable dependiente la carga de trabajo de enfermería -medida por el sistema Nursing Activities Score (NAS) de puntuación de actividades de enfermería. Para el análisis, se utilizaron el modelo de regresión lineal y la curva ROC. RESULTADOS 890 participantes (361 adultos mayores), en su mayoría varones (58,1%). La puntuación NAS promedio fue mayor entre los participantes adultos mayores en comparación con los adultos (p=0,004), pero no en las categorías de envejecimiento (p=0,697). La edad fue responsable del 0,6% de la puntuación NAS. Cada año de edad aumenta la puntuación NAS en 0,081 puntos (p=0,015). Sin embargo, la edad no resultó un buen predictor de la puntuación NAS (AbC=0,394; p=0,320). CONCLUSIÓN El cuidado de los adultos mayores en UCI se asocia con un aumento de la CTE en comparación con los adultos. El envejecimiento puede considerarse un factor asociado, pero no un buen predictor de la CTE en UCI.OBJETIVO Verificar se a idade é um preditor independente de Carga de trabalho de Enfermagem (CTE) em Unidade de Terapia Intensiva (UTI), de acordo com o grupo etário e qual sua capacidade preditiva como determinante de maior CTE em UTI. MÉTODO O estudo foi realizado entre 2012 e 2016. Amostra de conveniência composta por pacientes (idade ≥ 18) admitidos em nove UTI de um hospital universitário brasileiro. A idade foi considerada como variável independente e a CTE (mensurada pelo Nursing Activities Score ‒ NAS) como dependente. Os dados foram analisados por meio de análise de regressão linear e curva ROC. RESULTADOS 890 participantes (361 idosos), em sua maioria homens (58,1%). A média do NAS foi maior entre os idosos em comparação aos adultos (p=0,004), mas não entre os grupos etários (p=0,697). A idade foi responsável por 0,6% da pontuação do NAS. Para cada 1 ano de aumento da idade, a pontuação do NAS aumentou em 0,081 pontos (p=0,015). No entanto, a idade não foi um bom preditor de maior CTE (AUC = 0,394; p=0,320). CONCLUSÃO O cuidado de idosos em UTI está associado à maior CTE. A idade pode ser considerada um fator associado, mas não um bom preditor de CTE em UTI

The three-loop form factor in N=4 super Yang-Mills

In this paper we study the Sudakov form factor in {N} = {4} super Yang-Mills theory to the three-loop order. The latter is expressed in terms of planar and non-planar loop integrals. We show that it is possible to choose a representation in which each loop integral has uniform transcendentality. We verify analytically the expected exponentiation of the infrared divergences with the correct values of the three-loop cusp and collinear anomalous dimensions in dimensional regularisation. We find that the form factor in {N} = {4} super Yang-Mills can be related to the leading transcendentality part of the quark and gluon form factors in QCD. We also study the ultraviolet properties of the form factor in D > 4 dimensions, and find unexpected cancellations, resulting in an improved ultraviolet behaviour