Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

This work presents first insights into the dynamics of free-surface release clouds from dynamically compressed polystyrene and pyrolytic graphite at pressures up to 200 GPa, where they transform into diamond or lonsdaleite, respectively. These ejecta clouds are released into either vacuum or various types of catcher systems, and are monitored with high-speed recordings (frame rates up to 10 MHz). Molecular dynamics simulations are used to give insights to the rate of diamond preservation throughout the free expansion and the catcher impact process, highlighting the challenges of diamond retrieval. Raman spectroscopy data show graphitic signatures on a catcher plate confirming that the shock-compressed PS is transformed. First electron microscopy analyses of solid catcher plates yield an outstanding number of different spherical-like objects in the size range between ten(s) up to hundreds of nanometres, which are one type of two potential diamond candidates identified. The origin of some objects can unambiguously be assigned, while the history of others remains speculative

Carbon Dioxide Utilisation -The Formate Route

UIDB/50006/2020 CEEC-Individual 2017 Program Contract.The relentless rise of atmospheric CO2 is causing large and unpredictable impacts on the Earth climate, due to the CO2 significant greenhouse effect, besides being responsible for the ocean acidification, with consequent huge impacts in our daily lives and in all forms of life. To stop spiral of destruction, we must actively reduce the CO2 emissions and develop new and more efficient “CO2 sinks”. We should be focused on the opportunities provided by exploiting this novel and huge carbon feedstock to produce de novo fuels and added-value compounds. The conversion of CO2 into formate offers key advantages for carbon recycling, and formate dehydrogenase (FDH) enzymes are at the centre of intense research, due to the “green” advantages the bioconversion can offer, namely substrate and product selectivity and specificity, in reactions run at ambient temperature and pressure and neutral pH. In this chapter, we describe the remarkable recent progress towards efficient and selective FDH-catalysed CO2 reduction to formate. We focus on the enzymes, discussing their structure and mechanism of action. Selected promising studies and successful proof of concepts of FDH-dependent CO2 reduction to formate and beyond are discussed, to highlight the power of FDHs and the challenges this CO2 bioconversion still faces.publishersversionpublishe

Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

This work presents first insights into the dynamics of free-surface release clouds from dynamically compressed polystyrene and pyrolytic graphite at pressures up to 200 GPa, where they transform into diamond or lonsdaleite, respectively. These ejecta clouds are released into either vacuum or various types of catcher systems, and are monitored with high-speed recordings (frame rates up to 10 MHz). Molecular dynamics simulations are used to give insights to the rate of diamond preservation throughout the free expansion and the catcher impact process, highlighting the challenges of diamond retrieval. Raman spectroscopy data show graphitic signatures on a catcher plate confirming that the shock-compressed PS is transformed. First electron microscopy analyses of solid catcher plates yield an outstanding number of different spherical-like objects in the size range between ten(s) up to hundreds of nanometres, which are one type of two potential diamond candidates identified. The origin of some objects can unambiguously be assigned, while the history of others remains speculative

Management of Patients With Crohn's Disease and Ulcerative Colitis During the Coronavirus Disease-2019 Pandemic: Results of an International Meeting

The International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) is the only global organization devoted to the study of and management of the inflammatory bowel diseases (IBDs), namely, Crohn?s disease and ulcerative colitis. Membership is composed of physician-scientists who have established expertise in these diseases. The organization hosts an annual meeting and a number of working groups addressing issues of the epidemiology of IBD, diet and nutrition, and the development and use of treatments for IBD. There are currently 89 members of IOIBD representing 26 different countries. The organization has taken particular interest in the coronavirus disease-2019 (COVID-19) pandemic and how it may affect the IBD patient population. This document summarizes the results of 2 recent virtual meetings of the group and subsequent expert guidance for patients and providers

Association of the NOD2 genotype with bacterial translocation via altered cell-cell contacts in Crohn's disease patients

BACKGROUND: Recent insights into the pathogenesis of Crohn's disease (CD) point to an important role of the mucosal barrier and intestinal microflora that may induce a chronic inflammation after crossing the intestinal barrier. The first detected susceptibility gene for CD, NOD2, is a pattern recognition receptor (PRR) for the recognition of the bacterial cell wall component muramyldipeptide (MDP). Binding of MDP to NOD2 is followed by activation of proinflammatory pathways mainly regulated by nuclear factor kappa B (NF-kappaB). In this study we investigated whether impaired recognition of MDP via NOD2 variants is associated with increased bacterial translocation across the epithelial barrier and whether this is followed by increased or decreased NF-kappaB activation. METHODS: NOD2 variants were analyzed in 36 CD patients and 30 controls. Endotoxin was stained by immunohistochemistry in 30 intestinal biopsies from patients carrying NOD2 variants (NOD2-mut) or being NOD2 wildtype (WT). Junctional proteins were visualized by immunofluorescence and quantified by Western blotting. NF-kappaB activation was analyzed by immunohistochemistry in specimens from NOD2-WT and NOD2-mut CD and control patients. RESULTS: We demonstrated the increased presence of endotoxin in the mucosal lamina propria of CD patients carrying NOD2 variants. This was associated with an altered composition of epithelial cell-cell contacts. Patients carrying NOD2 variants displayed increased NF-kappaB activation in the mucosa. CONCLUSIONS: This study for the first time demonstrates that translocation of luminal bacteria and/or bacterial products into the intestinal mucosa is increased in patients carrying NOD2 variants, leading to higher activation of proinflammatory signaling cascades

Soluble galectin‐3 is a strong, colonic epithelial‐cell‐derived, lamina propria fibroblast‐stimulating factor

BACKGROUND: Colonic lamina propria fibroblasts (CLPFs) play an important role in the pathogenesis of fibrosis and strictures in Crohn's disease. AIM: To identify colonic epithelial cell (CEC)‐derived factors that activate CLPFs. METHODS: Primary human CECs and CLPFs were isolated from control mucosa and interleukin 8 (IL8) of CLPF cultures was quantified by ELISA. Activation of nuclear factor κB (NF‐κB) was shown, and translocation of NF‐κB was inhibited by a dominant‐negative IκB‐expressing adenovirus. The major CLPF‐activating and IL8 inducing protein was purified using fast‐performance liquid chromatography (HiPrep 16/60 Sephacryl S‐200 High Resolution Column) and sodium dodecyl sulphate gel electrophoresis. RESULTS: A considerable increase in IL8 secretion by CLPFs cultured in CEC‐conditioned media compared with that in unconditioned media (155.00 (10.00) pg/µg v 1.434 (0.695) pg/µg) was found. The effect of CEC‐conditioned media on CLPF IL8 secretion was NF‐κB dependent. A protein or DNA array confirmed the involvement of NF‐κB and activator protein‐1. Purification of a candidate band isolated with the use of sodium dodecyl sulphate‐polyacrylamide gel electrophoresis and subsequent sequencing showed soluble galectin‐3 to be a strong CLPF‐activating factor. Depletion of galectin‐3 from conditioned media by immunoprecipitation abolished the CLPF stimulatory effect. CONCLUSIONS: Using a classical biochemical approach, soluble galectin‐3 was identified as a strong activator of CLPFs produced by CEC. Galectin‐3 induced NF‐κB activation and IL8 secretion in these cells and may be a target for future therapeutic approaches to reduce or avoid stricture formation