Improving sustainable hydrogen production from green waste: [FeFe]-hydrogenases quantitative gene expression RT-qPCR analysis in presence of autochthonous consortia.

BACKGROUND: Bio-hydrogen production via dark fermentation of low-value waste is a potent and simple mean of recovering energy, maximising the harvesting of reducing equivalents to produce the cleanest fuel amongst renewables. Following several position papers from companies and public bodies, the hydrogen economy is regaining interest, especially in combination with circular economy and the environmental benefits of short local supply chains, aiming at zero net emission of greenhouse gases (GHG). The biomasses attracting the largest interest are agricultural and urban green wastes (pruning of trees, collected leaves, grass clippings from public parks and boulevards), which are usually employed in compost production, with some concerns over the GHG emission during the process. Here, an alternative application of green wastes, low-value compost and intermediate products (partially composted but unsuitable for completing the process) is studied, pointing at the autochthonous microbial consortium as an already selected source of implementation for biomass degradation and hydrogen production. The biocatalysts investigated as mainly relevant for hydrogen production were the [FeFe]-hydrogenases expressed in Clostridia, given their very high turnover rates. RESULTS: Bio-hydrogen accumulation was related to the modulation of gene expression of multiple [FeFe]-hydrogenases from two strains (Clostridium beijerinckii AM2 and Clostridium tyrobutyricum AM6) isolated from the same waste. Reverse Transcriptase quantitative PCR (RT-qPCR) was applied over a period of 288 h and the RT-qPCR results showed that C. beijerinckii AM2 prevailed over C. tyrobutyricum AM6 and a high expression modulation of the 6 different [FeFe]-hydrogenase genes of C. beijerinckii in the first 23 h was observed, sustaining cumulative hydrogen production of 0.6 to 1.2 ml H2/g VS (volatile solids). These results are promising in terms of hydrogen yields, given that no pre-treatment was applied, and suggested a complex cellular regulation, linking the performance of dark fermentation with key functional genes involved in bio-H2 production in presence of the autochthonous consortium, with different roles, time, and mode of expression of the involved hydrogenases. CONCLUSIONS: An applicative outcome of the hydrogenases genes quantitative expression analysis can be foreseen in optimising (on the basis of the acquired functional data) hydrogen production from a nutrient-poor green waste and/or low added value compost, in a perspective of circular bioeconomy.

Prevalence of obstructive sleep apnoea in acute coronary syndrome: Routine screening in intensive coronary care units.

INTRODUCTION: Increased evidence has shown that, despite the maximum care afforded to patients admitted with acute coronary syndromes (ACS), a residual risk of mortality remains, in which obstructive sleep apnoea (OSA) appears to be a largely undiagnosed factor, particularly in the intensive cardiac care unit (ICCU). The purpose of this study is to determine whether the systematic screening for sleep-disordered breathing (SDB) is feasible and may be recommended. The aims of our study are to determine: (1) The estimated prevalence of OSA in patients admitted to the ICCU for ACS determined by a validated, user-friendly portable screening device; (2) The feasibility of the screening in this context; (3) To assess any negative impact of OSA on the severity of ACS. PATIENTS AND METHODS: This is an observational study of 101 patients admitted to the ICCU for ACS showing no clinical evidence of heart failure (HF). In the 24-72hours following admission, they underwent an overnight sleep study using a 3-channel portable screening device with automatic analysis. RESULTS: Sixty-two out of the 101 patients proved positive to the screening test, and its feasibility was acceptable. OSA patients tended to have greater peak levels of hs-cTnT (3685±3576ng/L versus 2830±3333ng/L, P=0.08) than the non-OSA group. Compared with the non-OSA group, OSA patients presented more severe ACS, with a greater average GRACE score at admission of 112.2±26.3 (versus 98.4±19.2, P<0.001). In the OSA group, we found a statistically significant inverse correlation between the apnoea-hypopnea index (AHI) and the left ventricular ejection fraction (LVEF) in the linear regression analysis (r=-0.26; P=0.037). CONCLUSIONS: A systematic screening of patients in the ICCU is acceptable. OSA is frequently found in the acute phase of ischaemic heart disease and its presence is associated with more severe ACS and a poorer left ventricle systolic function.

A new model of verbal short-term memory.

Two experiments tested a neo-Piagetian model of verbal short-term memory and compared it with the articulatory loop model. Experiment 1 (n = 113, age range 9-11) tested word span for 2-, 3-, and 4-syllable words, with both visual and auditory presentation. Experiment 2 (with the same participants) tested recall of visually presented supraspan lists. Measures of M capacity (as conceived in Pascual-Leone's neo-Piagetian theory) and articulation rate were also used. The proposed model can account for the effects of M capacity, word length, and presentation modality. The fit of this model to the data was acceptable, and parameter estimates were consistent across experiments. Furthermore, a correlation was found between M capacity and word span which resisted partialling out of age and articulation rate.

Planning, Encoding, and Overcoming Conflict in Partial Occlusion Drawing: A Neo-Piagetian Model and an Experimental Analysis

A theoretical model of partial occlusion drawing is presented, along with three experiments. The experiments used the materials similarity effect, i.e., the fact that it is easier to draw partial occlusion when the model objects are quite different from each other (Cox, 1985). Experiment 1, with 172 5- to 8-year-old subjects, manipulated materials (similar vs dissimilar objects) and viewing condition (unlimited visibility vs screened after 5 s), to study whether planning or scanning is involved in partial occlusion drawing. The results were consistent with the planning hypothesis, but not with the scanning hypothesis. Experiment 2, with 76 first-graders, explored group-encoding of similar objects. Encoding was assessed from verbal descriptions. Layouts were described differently (similar objects yielding group descriptions), and different descriptions were correlated with different drawing strategies. We suggest that group-encoding of similar objects creates a drawing problem (Experiment 2), and planning is required to solve it (Experiment 1). A neo-Piagetian model that accounts for drawing performance in terms of incompatible sets of activated schemes and of an activation balance between them is presented. Both experimental manipulations and differences among subjects in attentional resources are assumed to affect this balance. Three predictions were derived on the conjoint effects of object similarity and subject's M capacity and field dependence on drawing; Experiment 3, with 79 first-graders, successfully tested them.

Attention and control deficits following closed head injury.

This study was aimed at identifying the impaired attentional components in patients who had sustained a severe CHI several years before. A group of 14 CHI patients and a Control group (matched for age, sex and education) were tested. Experiment 1 used a dual-task paradigm (Umiltà et al., 1992). The double task-single task difference was greater for the CHI group, indicating a specific damage at a central executive stage where decision are made and responses are coordinated. Experiment 2 used a task-shifting paradigm (Morra and Roncato, 1986). The cost of shifting from one task to the other was greater for the CHI group, but only in the Short Series Condition where a new task-program could be pre-activated. Experiment 3 studied visual selective attention using Navon paradigm (1977); in this case, there was no difference between patients and controls.

[Use of atracurium in continuous intravenous infusion]. / Impiego dell'atracurium in infusione endovenosa continua.

In this study the use of atracurium was evaluated for use in continuous endovenous infusion by controlling infusion levels using the simple technique of TOF monitoring during general surgical operations. In conclusion, continuous infusion of blocking agents is the preferential technique for controlling and maintaining a neuromuscular block; moreover, the use of besylate of atracurium is advised to ensure a reduced rate of individual variation.

[Comparative evaluation of several muscle relaxants]. / Valutazione comparativa di differenti miorilassanti.

The use of different muscle relaxants have been studied in two homogeneous groups of patients, in the first group atracurium and in the second succinylcholine-pancuronium. The utility of atracurium in short-medium abdominal surgery has been demonstrated.