RAFT Polymerization of a Biorenewable/Sustainable Monomer via a Green Process

A biorenewable polymer is synthesized via a green process using the RAFT principle for the first time in supercritical CO2 at 300 bar and 80 °C. α-Methylene-γ-butyrolactone polymers of various chain lengths and molecular weights are obtained. The molecular weights vary from 10 000 up to 20 000 with low polydispersity indexes (PDI <1.5). Furthermore, the monomer conversion in supercritical CO2 is substantially higher, respectively 85% for ScCO2 compared to ≈65% for polymerizations conducted in dimethyl formamide (DMF) solvent. Chain extensions are carried out to confirm the livingness of the formed polymers in ScCO2. This opens up future possibilities of the formation of different polymer architectures in ScCO2. The polymers synthesized in ScCO2 have glass transition temperature (Tg) values ranging from 155 up to 190 °C. However, the presence of residual monomer encapsulated inside the formed polymer matrix affects the glass transition of the polymer that is lowered by increasing monomer concentrations. Hence, additional research is required to eliminate the remaining monomer concentration in the polymer matrix in order to arrive at the optimal Tg

Solid-state NMR spectroscopy insights for resolving different water pools in alginate hydrogels

Alginate hydrogels are versatile self-assembling biocompatible materials with diverse biomedical and food industrial applications, which includes uses in encapsulation, (drug) delivery and tissue engineering. Hydrogel formation requires cross-linking, which for alginates is often done with calcium ions that engage in specific interactions with the polysaccharide carboxylic acid groups. Water molecules also hydrate these alginate groups and fill macropores within the hydrogels, with implications for both mechanical properties and cargo encapsulation. Understanding these aspects of hydrogels requires the observation and characterization of the hydrogel waters, how they engage the alginate, and fill the macropores. Here we employed solid-state NMR (ssNMR) spectroscopy to detect and study water molecules in re-hydrated alginate hydrogels. 1H, 2H, and 13C magic angle spinning (MAS) NMR and relaxation measurements were combined to observe both water and alginate. Two different water phases were detected that vary upon gradual (re)hydration of the alginate hydrogels. These water pools differ in their chemical shifts and NMR relaxation properties, reflecting hydration waters directly associated with the carbohydrate polymers alongside dynamic waters in the macropores. Thus, the ssNMR detects the water-filled macropore water pools and how they vary upon calcium cross-linking. We also observe how calcium cross-linking selectively immobilizes the α-guluronate monosaccharides, but leaves the β-mannuronate units more flexible and prone to selective re-hydration. Thus, these ssNMR experiments can be used to probe cross-linking and hydration of alginate hydrogels, with implications for our understanding of design parameters that tune their performance in (drug) delivery and other food industrial applications

Telemedicine as a Medical Examination Tool During the Covid-19 Emergency: The Experience of the Onco-Haematology Center of Tor Vergata Hospital in Rome

Background: Our study analysed the outpatient activity of the onco-hematology Complex Operative Unit (UOC) of Tor Vergata Hospital, Rome coronavirus disease 2019 (Covid-19) center, where, as a result of the sudden and unexpected emergency, healthcare services were provided through telemedicine procedures that can be considered very close to Telehealth. Aim of the study: our retrospective study aimed to assess the widespread use of telemedicine in terms of feasibility and safety related to adverse events, a crucial experience which will make it possible to predict any effective use of such a method in patients with hematological disorders even after the end of the Covid-19 emergency. Materials and methods: At the Day Hospital clinic, from 8 March to 31 May 2020, an outpatient group received 3828 medical teleconsultations and 11,484 additional contacts following the first examination; each patient examined through the telematic method required an average of three supplementary contacts via e-mail or telephone. Results: The follow-up lasted 145 days, and all the events that occurred were monitored. In total, we recorded 16 clinical adverse events, 5 of which classified as major events, and 11 as minor events. Conclusion: The 3828 telematic clinical examinations and the 11,484 additional contacts following the first examination carried out by the onco-haematology UOC of Tor Vergata Hospital, proved how telemedicine, albeit in its basic form, was a key tool in facing the sanitary emergency caused by the sudden spread of Covid-19. An experience that can be considered reliable enough to be replicated in possible post-Covid-19 emergencies. From a medical forensic point of view, the main issues to consider are informed consent, personal data management and professional responsibility profiles

Iron Tetrasulfonatophthalocyanine-Catalyzed Starch Oxidation Using H2O2:Interplay between Catalyst Activity, Selectivity, and Stability

Oxidized starch can be efficiently prepared using H2O2 as an oxidant and iron(III) tetrasulfophthalocyanine (FePcS) as a catalyst, with properties in the same range as those for commercial oxidized starches prepared using NaOCl. Herein, we performed an in-depth study on the oxidation of potato starch focusing on the mode of operation of this green catalytic system and its fate as the reaction progresses. At optimum batch reaction conditions (H2O2/FePcS molar ratio of 6000, 50 °C, and pH 10), a high product yield (91 wt %) was obtained with substantial degrees of substitution (DSCOOH of 1.4 and DSCO of 4.1 per 100 AGU) and significantly reduced viscosity (197 mPa·s) by dosing H2O2. Model compound studies showed limited activity of the catalyst for C6 oxidation, indicating that carboxylic acid incorporation likely results from C-C bond cleavage events. The influence of the process conditions on the stability of the FePcS catalyst was studied using UV-vis and Raman spectroscopic techniques, revealing that both increased H2O2 concentration and temperature promote the irreversible degradation of the FePcS catalyst at high pH. The rate and extent of FePcS degradation were found to strongly depend on the initial H2O2 concentration where also the rapid decomposition of H2O2 by FePcS occurs. These results explain why the slow addition of H2O2 in combination with low FePcS catalyst concentration is beneficial for the efficient application in starch oxidation

Psychosis Endophenotypes:A Gene-Set-Specific Polygenic Risk Score Analysis

Background and Hypothesis:Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes.Study Design:We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score.Study Results:After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: −1.15 µV; 95% CI: −1.70 to −0.59 µV; P = 6 × 10−5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores.Conclusions:Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models

Nonlinear complexity analysis of brain fMRI signals in schizophrenia

Peer reviewedPublisher PD

Gender Differences in White Matter Microstructure

Sexual dimorphism in human brain structure is well recognised, but little is known about gender differences in white matter microstructure. We used diffusion tensor imaging to explore differences in fractional anisotropy (FA), an index of microstructural integrity.A whole brain analysis of 135 matched subjects (90 men and 45 women) using a 1.5 T scanner. A region of interest (ROI) analysis was used to confirm those results where proximity to CSF raised the possibility of partial-volume artefact.Men had higher fractional anisotropy (FA) in cerebellar white matter and in the left superior longitudinal fasciculus; women had higher FA in the corpus callosum, confirmed by ROI.The size of the differences was substantial--of the same order as that attributed to some pathology--suggesting gender may be a potentially significant confound in unbalanced clinical studies. There are several previous reports of difference in the corpus callosum, though they disagree on the direction of difference; our findings in the cerebellum and the superior longitudinal fasciculus have not previously been noted. The higher FA in women may reflect greater efficiency of a smaller corpus callosum. The relatively increased superior longitudinal fasciculus and cerebellar FA in men may reflect their increased language lateralisation and enhanced motor development, respectively

Intelligence, educational attainment, and brain structure in those at familial high-risk for schizophrenia or bipolar disorder

First-degree relatives of patients diagnosed with schizophrenia (SZ-FDRs) show similar patterns of brain abnormalities and cognitive alterations to patients, albeit with smaller effect sizes. First-degree relatives of patients diagnosed with bipolar disorder (BD-FDRs) show divergent patterns; on average, intracranial volume is larger compared to controls, and findings on cognitive alterations in BD-FDRs are inconsistent. Here, we performed a meta-analysis of global and regional brain measures (cortical and subcortical), current IQ, and educational attainment in 5,795 individuals (1,103 SZ-FDRs, 867 BD-FDRs, 2,190 controls, 942 schizophrenia patients, 693 bipolar patients) from 36 schizophrenia and/or bipolar disorder family cohorts, with standardized methods. Compared to controls, SZ-FDRs showed a pattern of widespread thinner cortex, while BD-FDRs had widespread larger cortical surface area. IQ was lower in SZ-FDRs (d = −0.42, p = 3 × 10−5), with weak evidence of IQ reductions among BD-FDRs (d = −0.23, p =.045). Both relative groups had similar educational attainment compared to controls. When adjusting for IQ or educational attainment, the group-effects on brain measures changed, albeit modestly. Changes were in the expected direction, with less pronounced brain abnormalities in SZ-FDRs and more pronounced effects in BD-FDRs. To conclude, SZ-FDRs and BD-FDRs show a differential pattern of structural brain abnormalities. In contrast, both had lower IQ scores and similar school achievements compared to controls. Given that brain differences between SZ-FDRs and BD-FDRs remain after adjusting for IQ or educational attainment, we suggest that differential brain developmental processes underlying predisposition for schizophrenia or bipolar disorder are likely independent of general cognitive impairment

Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes

publisher: Elsevier articletitle: Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes journaltitle: Cell articlelink: https://doi.org/10.1016/j.cell.2018.05.046 content_type: article copyright: © 2018 Elsevier Inc