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Selective hydrogenolysis of the aromatic carbon-oxygen (C-O) bonds in aryl ethers is an unsolved synthetic problem important for the generation of fuels and chemical feedstocks from biomass and for the liquefaction of coal. Currently, the hydrogenolysis of aromatic C-O bonds requires heterogeneous catalysts that operate at high temperature and pressure and lead to a mixture of products from competing hydrogenolysis of aliphatic C-O bonds and hydrogenation of the arene. Here, we report hydrogenolyses of aromatic C-O bonds in alkyl aryl and diaryl ethers that form exclusively arenes and alcohols. This process is catalyzed by a soluble nickel carbene complex under just 1 bar of hydrogen at temperatures of 80 to 120°C; the relative reactivity of ether substrates scale as Ar-OAr>>Ar-OMe>ArCH₂-OMe (Ar, Aryl; Me, Methyl). Hydrogenolysis of lignin model compounds highlights the potential of this approach for the conversion of refractory aryl ether biopolymers to hydrocarbons.

A new theory for the study of the reactivity in Organic Chemistry, named Molecular Electron Density Theory (MEDT), is proposed herein. MEDT is based on the idea that while the electron density distribution at the ground state is responsible for physical and chemical molecular properties, as proposed by the Density Functional Theory (DFT), the capability for changes in electron density is responsible for molecular reactivity. Within MEDT, the reactivity in Organic Chemistry is studied through a rigorous quantum chemical analysis of the changes of the electron density as well as the energies associated with these changes along the reaction path in order to understand experimental outcomes. Studies performed using MEDT allow establishing a modern rationalisation and to gain insight into molecular mechanisms and reactivity in Organic Chemistry.

Realizing the extraordinary potential of unactivated sp³ C-H bond oxidation in organic synthesis requires the discovery of catalysts that are both highly reactive and predictably selective. We report an iron (Fe)-based small molecule catalyst that uses hydrogen peroxide (H₂O₂) to oxidize a broad range of substrates. Predictable selectivity is achieved solely on the basis of the electronic and steric properties of the C-H bonds, without the need for directing groups. Additionally, carboxylate directing groups may be used to furnish five-membered ring lactone products. We demonstrate that these three modes of selectivity enable the predictable oxidation of complex natural products and their derivatives at specific C-H bonds with preparatively useful yields. This type of general and predictable reactivity stands to enable aliphatic C-H oxidation as a method for streamlining complex molecule synthesis.

The interaction of physical and mental vulnerability and environmental constraints is thought to foster the development of psychiatric disorders such as major depressive disorder (MDD). A central factor in the development of psychopathology is mental stress. Despite some evidence for parasympathetic withdrawal and sympathetic overactivity in MDD, the psychophysiological response to stress in depression is not clear-cut. Given the growing interest in heart rate and heart rate variability as indicators for remote monitoring of patients, it is important to understand how patients with MDD react to stress in a laboratory-controlled environment. We conducted a systematic review of studies using electrocardiography to derive heart rate and heart rate variability during stress in patients with clinical depression. We focused on well-validated stress tasks- the mental arithmetic stress task, the Trier social stress task and public speaking task- to minimize confounding effects due to the nature of the stressor. The majority of studies found hypo-reactivity during stress as a hallmark of depression as evidenced by lower fluctuation in heart rate and heart rate variability in the high-frequency band. We address the potential underlying biological mechanisms, the influence of covariates on these measures and briefly discuss the specificity and potential for remote monitoring by using these variables.

Studies indicate that gut microbiota is related to neurodevelopmental and behavioral outcomes. Accordingly, early gut microbiota composition (GMC) has been linked to child temperament, but research is still scarce. The aim of this study was to examine how early GMC at 2.5 months is associated with child negative and fear reactivity at 8 and 12 months since they are potentially important intermediate phenotypes of later child psychiatric disorders. Our study population was 330 infants enrolled in the longitudinal FinnBrain Birth Cohort Study. Gut microbiota composition was analyzed using stool sample 16s rRNA sequencing. Negative and fear reactivity were assessed using the Laboratory Temperament Assessment Battery (Lab-TAB) at child's age of 8 months ( =150) and the Infant Behavior Questionnaire-Revised Short Form (IBQ-R SF) at child's age of 12 months ( = 276). We found a positive association between alpha diversity and reported fear reactivity and differing microbial community composition based on negative reactivity for boys. Isobutyric acid correlated with observed negative reactivity, however, this association attenuated in the linear model. Several genera were associated with the selected infant temperament traits. This study adds to the growing literature on links between infant gut microbiota and temperament informing future mechanistic studies.

Alkaline reactivity characterizes the dissolution and reactive capacity of a solid material in alkaline media. The results are of significance in the development of technology for geopolymers obtaining based on the studied raw materials. However, no validated analytical procedure for estimation of alkaline reactivity of coal combustion by-products and mine tailing exists. It imposed the development of specific procedure for analysis and its verification. This report presents a procedure based on ICP-OES measurement of the concentration of Al, Si and Ca in alkali solution. Some problems of the analysis were successfully addressed, as a high salt content of leachates, and the procedure was verified applying a reference laboratory approach. The alkaline reactivity was studied as a function of time at 6.5 M NaOH during 48 h. Additionally, to reactive silica determination, the study was extended to reactive alumina and calcium, as these components contribute to the development of geopolymer matrix. To estimate the percentage of dissolved Al, Si and Ca detailed precise data about chemical composition of raw materials were required. To achieve it, samples components were determined by ICP-OES after digestion in acid oxidizing medium, combined with alkali fusion for silica determination, as well as loss of ignition and humidity determination. In contrast to the approach, usually reported in the literature, presenting the alkaline reactivity as a concentration of dissolved ions in the alkaline solution, in this study we proposed a new procedure. Alkaline reactivity was estimated: by a percentage of dissolved component in mg per kg dry sample. This approach allowed comparability of the data between various laboratories, procedures or raw materials. Moreover, the approach allowed the relative ratio between reactive components to be calculated.

Recent studies found that making judgments of learning (JOLs) can reactively facilitate memory, a phenomenon termed the reactivity effect of JOLs. The current study was designed to explore (1) whether making judgments of forgetting (JOFs) can also enhance memory and (2) whether there is any difference between the reactivity effects of JOFs and JOLs. Experiment 1 found that soliciting JOFs significantly enhanced retention of single words. Experiments 2 and 3 observed minimal difference in reactivity effects between JOFs and JOLs on learning of single words and word pairs. Finally, a meta-analysis was conducted to integrate results across studies to explore whether retention of items studied with JOLs differed from that of items studied with JOFs. The meta-analytic results showed minimal difference. Overall, the documented findings imply that (1) making JOFs reactively enhances memory, and (2) there is little difference in reactivity effects between JOFs and JOLs. These findings support the positive-reactivity theory to account for the reactivity effect.

The capacity to shift experiential perspective—from within one's subjective experience onto that experience—is fundamental to being human. Scholars have long theorized that this metacognitive capacity—which we refer to as decentering—may play an important role in mental health. To help illuminate this mental phenomenon and its links to mental health, we critically examine decentering-related constructs and their respective literatures (e.g., self-distanced perspective, cognitive distancing, cognitive defusion). First, we introduce a novel metacognitive processes model of decentering. Specifically, we propose that, to varying degrees, decentering-related constructs reflect a common mental phenomenon subserved by three interrelated metacognitive processes: meta-awareness, disidentification from internal experience, and reduced reactivity to thought content. Second, we examine extant research linking decentering-related constructs and their underlying metacognitive processes to mental health. We conclude by proposing future directions for research that transcends decentering-related constructs in an effort to advance the field's understanding of this facet of human experience and its role in (mal)adaptation.

Background The ultra-low-frequency pressure reactivity index (UL-PRx) has been established as a surrogate method for bedside estimation of cerebral autoregulation (CA). Although this index has been shown to be a predictor of outcome in adult and pediatric patients with traumatic brain injury (TBI), a comprehensive evaluation of low sampling rate data collection (0.0033 Hz averaged over 5 min) on cerebrovascular reactivity has never been performed. Objective To evaluate the performance and predictive power of the UL-PRx for 12-month outcome measures, alongside all International Mission for Prognosis and Analysis of Clinical Trials (IMPACT) models and in different age groups. To investigate the potential for optimal cerebral perfusion pressure (CPPopt). Methods Demographic data, IMPACT variables, in-hospital mortality, and Glasgow Outcome Scale Extended (GOSE) at 12 months were extracted. Filtering and processing of the time series and creation of the indices (cerebral intracranial pressure (ICP), cerebral perfusion pressure (CPP), UL-PRx, and deltaCPPopt (ΔCPPopt and CPPopt-CPP)) were performed using an in-house algorithm. Physiological parameters were assessed as follows: mean index value, % time above threshold, and mean hourly dose above threshold. Results A total of 263 TBI patients were included: pediatric (17.5% aged ≤ 16 y) and adult (60.5% aged > 16 and < 70 y and 22.0% ≥ 70 y, respectively) patients. In-hospital and 12-month mortality were 25.9% and 32.7%, respectively, and 60.0% of patients had an unfavorable outcome at 12 months (GOSE). On univariate analysis, ICP, CPP, UL-PRx, and ΔCPPopt were associated with 12-month outcomes. The cutoff of ~ 20–22 for mean ICP and of ~ 0.30 for mean UL-PRx were confirmed in all age groups, except in patients older than 70 years. Mean UL-PRx remained significantly associated with 12-month outcomes even after adjustment for IMPACT models. This association was confirmed in all age groups. UL-PRx resulted associate with CPPopt. Conclusions The study highlights UL-PRx as a tool for assessing CA and valuable outcome predictor for TBI patients. The results emphasize the potential clinical utility of the UL-PRx and its adaptability across different age groups, even after adjustment for IMPACT models. Furthermore, the correlation between UL-PRx and CPPopt suggests the potential for more targeted treatment strategies. Trial registration : ClinicalTrials.gov identifier: NCT05043545, principal investigator Paolo Gritti, date of registration 2021.08.21.