A novel hydro-pneumatic fluid percussion device for inducing traumatic brain injury: assessment of sensory, motor, cognitive, molecular, and morphological outcomes in rodents

IntroductionThe fluid percussion method is widely used to induce brain injury in rodents. However, this approach has several limitations, including variability in the resulting damage, which is attributed to factors such as manual control of the mass used to generate the desired pressure. To address these issues, several modifications to the original method have been proposed.MethodsIn this study, we present a novel device called the Hydro-pneumatic Fluid Percussion Device, which delivers fluid directly to a lateral region of the brain to induce injury. To validate this model, three groups of male and female rats were subjected to lateral fluid percussion using our device, and the resulting damage was evaluated using sensory, motor, and cognitive tests, measurements of serum injury biomarkers, and morphological analysis via cresyl violet staining.ResultsOur results demonstrate that this new approach induced significant alterations in all parameters evaluated.DiscussionThis novel device for inducing TBI may be a valuable alternative for modeling brain injury and studying its consequences

Flexible Power Flow for Controlled Islanded Microgrids Including Battery Energy Storage Systems

This paper addresses the formulation problem of a power flow for controlled islanded microgrids including battery energy storage systems. The formulation considers droop-based primary controllers, probability-based wind distributions and power curves for the distributed generation units, and sigmoid-based models for the BESS operation and the load shedding. Two case studies are addressed where different BESS conditions are selected to highlight its role in the islanded microgrid, and its impact in the microgrid operative steady-state dynamics. The obtained results corroborate the proposed power flow formulation reliability for representing the controlled islanded microgrid and its usefulness for detailed operative planning and design.</p

Hierarchical Power Flow Voltage Assessment of a Multi-Microgrid in Interconnected Operation Mode

This paper presents a voltage assessment of the IEEE six-bus system including two controlled microgrids using the hierarchical power flow approach. Two case studies are presented, the first case considers only primary droop controls for the distributed generation units, and the second case considers primary droop and secondary controls. The results shown that there is a difference in the analysis results if only primary controls are considered or hierarchical controls. In this way, it is shown that the microgrid connection impacts in the overall system voltage profile and indicate that planning analysis, considering the detailed modelling of the different distributed generation units' hierarchical controls, is required for the optimal inclusion of microgrids into the main grid.</p

Antarctic bacterial haemoglobin and its role in the protection against nitrogen reactive species

In a cold and oxygen-rich environment such as Antarctica, mechanisms for the defence against reactive oxygen and nitrogen species are needed and represent important components in the evolutionary adaptations. In the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125, the presence of multiple genes encoding 2/2 haemoglobins and a flavohaemoglobin strongly suggests that these proteins fulfil important physiological roles, perhaps associated to the peculiar features of the Antarctic habitat. In this work, the putative role of Ph-2/2HbO, encoded by the PSHAa0030 gene, was investigated by in vivo and in vitro experiments in order to highlight its involvement in NO detoxification mechanisms. The PSHAa0030 gene was cloned and then over-expressed in a flavohaemoglobin-deficient mutant of Escherichia coli, unable to metabolise NO, and the resulting strain was studied analysing its growth properties and oxygen uptake in the presence of NO. We here demonstrate that Ph-2/2HbO protects growth and cellular respiration of the heterologous host from the toxic effect of NO-donors. Unlike in Mycobacterium tuberculosis 2/2 HbN, the deletion of the N-terminal extension of Ph-2/2HbO does not seem to reduce the NO scavenging activity, showing that the N-terminal extension is not a requirement for efficient NO detoxification. Moreover, the ferric form of Ph-2/2HbO was shown to catalyse peroxynitrite isomerisation in vitro, confirming its potential role in the scavenging of reactive nitrogen species. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Protein

Immediate Postpartum Breastfeeding Following Pregnancy with Cardiac Disease

This study aimed to identify predictors of immediate postpartum breastfeeding among women with maternal cardiac disease (MCD). This study included all gravidas with MCD who delivered at a single institution from 2012 to 2018. Charts were abstracted for maternal demographics, obstetrical outcome, cardiac diagnoses, cardiac risk stratification scores, and prepregnancy echocardiogram findings. Kruskal-Wallis and Fisher's exact tests were used to compare the breastfeeding (BF) group versus the nonbreastfeeding (NBF) group. Logistic regression was used to obtain odds ratios (ORs) with 95% confidence intervals (CIs). Among 211 gravidas with MCD, 12% were not breastfeeding at the time of postpartum hospital discharge. Compared with the BF group, the NBF group had a significantly higher proportion of women with cardiomyopathy (21% NBF vs. 7% BF, OR 3.44, 95% CI 1.12-10.71), with modified World Health Organization (WHO) classification ≥III (33 vs. 14%, OR 3.16, 95% CI 1.22-8.15), and with prepregnancy ejection fraction (EF) < 50% (55 vs. 14%, OR 7.20, 95% CI 1.92-27.06). There were otherwise no differences between the two groups with regards to other cardiac diagnoses or cardiac risk scores. In women with MCD, cardiomyopathy, modified WHO class ≥III, and a prepregnancy EF < 50% were associated with NBF in the immediate postpartum period. These findings may guide providers in identifying a subset of women with MCD who can benefit from increased breastfeeding counseling and support.· Eighty-two percent of patients with cardiac disease are breastfeeding at the time of postpartum discharge.. · Cardiomyopathy is associated with an increased odds of not breastfeeding at postpartum discharge.. · Rationale for not breastfeeding is infrequently documented in the medical record.