Tight glucose control: should we move from intensive insulin therapy alone to modulation of insulin and nutritional inputs?

The report by Chase and coworkers in the previous issue of Critical Care describes the implementation into clinical practice of the Specialized Relative Insulin Nutrition Table (SPRINT) for tight glycaemic control in critically ill patients. SPRINT is a simple, wheel-based system that modulates both insulin rate and nutritional inputs. It achieved a better glycaemic control in a severely ill critical cohort than their previous method for glycaemic control in a matched historical cohort. Reductions in mortality were also observed

Geometrically nonlinear theory of thin-walled composite box beams using shear-deformable beam theory

A general geometrically nonlinear model for thin-walled composite space beams with arbitrary lay-ups under various types of loadings is presented. This model is based on the first-order shear deformable beam theory, and accounts for all the structural coupling coming from both material anisotropy and geometric nonlinearity. The nonlinear governing equations are derived and solved by means of an incremental Newton–Raphson method. A displacement-based one-dimensional finite element model that accounts for the geometric nonlinearity in the von Kármán sense is developed. Numerical results are obtained for thin-walled composite box beams under vertical load to investigate the effects of shear deformation, geometric nonlinearity and fiber orientation on axial–flexural–torsional response

Geometrically nonlinear analysis of thin-walled composite box beams

A general geometrically nonlinear model for thin-walled composite space beams with arbitrary lay-ups under various types of loadings has been presented by using variational formulation based on the classical lamination theory. The nonlinear governing equations are derived and solved by means of an incremental Newton–Raphson method. A displacement-based one-dimensional finite element model that accounts for the geometric nonlinearity in the von Kármán sense is developed. Numerical results are obtained for thin-walled composite box beam under vertical load to investigate the effect of geometric nonlinearity and address the effects of the fiber orientation, laminate stacking sequence, load parameter on axial–flexural–torsional response

Hidden patterns of codon usage bias across kingdoms

The genetic code encodes 20 amino acids using 64 nucleotide triplets or codons. 18 of the 20 amino acids are encoded by multiple synonymous codons which are used in organismal genomes in a biased fashion. Codon bias arises because evolutionary selection favours particular nucleotide sequences over others encoding the same amino acid sequence. Despite many existing hypotheses, there is no current consensus on what the evolutionary drivers are. Using ideas from stochastic thermodynamics we derive from first principles a mathematical model describing the statistics of codon usage bias and apply it to extensive genomic data. Our main conclusions include the following findings: (1) Codon usage cannot be explained solely by selection pressures that act on the genome-wide frequency of codons, but also includes pressures that act at the level of individual genes. (2) Codon usage is not only biased in the usage frequency of nucleotide triplets but also in how they are distributed across mRNAs. (3) A new model-based measure of codon usage bias that extends existing measures by taking into account both codon frequency and codon distribution reveals distinct, amino acid specific patterns of selection in distinct branches of the tree of life

Patient comfort during critical illness special issue

Pain, anxiety, agitation and delirium have been associated with cognitive impairments, poor health-related quality of life, and mortality in both adults and children. A proactive approach to early, effective assessment is a pre-requisite for appropriate management of those symptoms and is a core element of nursing care of critically ill patients. As nurses are at the bedside 24/7, it is essential for them to show leadership in this area of practice that requires the input of the inter-disciplinary team to achieve high quality outcomes for the patient. This special issue is a demonstration of the growing body of science available to address the diverse challenges in assessment and care in this area

Postpartum acute stress disorder symptoms, social support, and quality of couple’s relationship associations with childbirth PTSD

BackgroundWe aimed to examine the hypothesized negative associations between childbirth post-traumatic stress disorder (PTSD) symptoms (using the two-factor model of birth-related and general symptoms), social support, and a couple’s relationship quality at 8–12 weeks postpartum. This analysis considered the longitudinal positive shared variance with acute stress disorder (ASD) symptoms measured shortly after birth, while accounting for obstetric and demographic variables.MethodsParticipants included 246 mothers who gave birth at the maternity ward of a tertiary healthcare center. Self-report questionnaires were used 1–4 days postpartum (T1): Demographic information, the Birth Satisfaction Scale-Revised (BSS-R), and the National Stressful Events Survey Acute Stress Disorder Short Scale (NSESSS). At T2 (8–12 weeks postpartum), the Multidimensional Scale of Perceived Social Support (MSPSS), the Dyadic Adjustment Scale (DAS-7), and the City Birth Trauma Scale (BiTS).ResultsIn partial support of our hypotheses, three hierarchical regression analyses revealed a significant positive contribution of ASD symptoms to childbirth PTSD general symptoms (β = .33, p <.001) and the total score (β = .29, p <.001), but not to birth-related symptoms. Social support (β = -.21, p = .003) and the quality of the couple’s relationship (β=-.20, p = .003) showed negative associations with the BiTS general symptoms.ConclusionOur study enhances understanding of the shared variance between childbirth ASD and PTSD, supporting the factor structure of general and birth-related symptoms as different aspects of childbirth PTSD and highlighting the negative association of social support and the quality of a couple’s relationship with PTSD general symptoms, suggesting potential avenues for targeted interventions