A novel rational synthetic pathway—the “functionalization of para‐nitroaniline” (FpNA)—provides substituted hexaarylbenzenes (HABs) with uncommon symmetries that bear up to five different ...substituents, fully avoiding regioisomeric product distributions during the reactions. 4‐Nitroaniline is functionalized by a cascade of electrophilic halogenations, Sandmeyer brominations, and Suzuki cross‐coupling reactions, leading to 26 substitution geometries, of which 18 structures are not available by the current established techniques. Furthermore, we demonstrate that this method is applicable to the bulk production of such systems on a multigram scale. Regarding optoelectronic properties, we demonstrate how highly functionalized HABs can show strong luminescent behavior, making these molecules very attractive to organic electronic devices.
Bulk discount on hexaarylbenzenes (HABs): A rational and scalable synthesis of uncommon and highly functionalized HABs utilizes 4‐nitroaniline as the starting material. This approach can potentially provide 18 novel HABs and 26 substitution geometries in total, which are not available or only difficult to obtain by standard techniques.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A synthetic route towards a novel hexabenzocoronene‐based helical nanographene motif was developed. A hexaphenylbenzene precursor was therefore designed, which cannot undergo, due to steric ...restrictions, a complete planarization reaction. This precursor was transformed under oxidative cyclodehydrogenation conditions to a π‐extended 5helicene, which was fully characterized including X‐ray diffraction analysis.
A twisted nanographene that is based on the well‐established hexabenzocoronene motif is presented. A 5helical unit was implemented into the nanographene structure with the help of steric repulsive effects. The π‐extended helicene was characterized by UV/Vis absorption and emission spectroscopy as well as X‐ray crystallography.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
OBJECTIVES:Prior studies report significant mortality in fibrotic interstitial lung disease patients undergoing mechanical ventilation. Little is known about baseline characteristics or ventilator ...strategies that might improve outcomes. We analyzed the ventilator characteristics of a large cohort of fibrotic interstitial lung disease patients from the perspective of an acute respiratory distress syndrome paradigm to see if any specific mechanical ventilation strategies might improve in-hospital mortality.
DESIGN:Retrospective cohort study.
SETTING:Single-center, multihospital medical ICUs.
PATIENTS:Consecutive fibrotic interstitial lung disease patients who experienced mechanical ventilation for acute respiratory failure.
INTERVENTIONS:Interstitial lung disease characteristics, demographics, and ventilator variables were analyzed for univariable and multivariable predictors of in-hospital mortality, adjusted for confounding with an a priori causation model.
MEASUREMENTS AND MAIN RESULTS:A total of 111 patients accounted for 114 admissions. Idiopathic pulmonary fibrosis comprised 34% with idiopathic acute exacerbation (65%) being the most common admission type. Ninety-five percent were initiated on mandatory volume-control ventilation with only 50% achieving a low tidal volume strategy (plateau pressure ≤ 30 cm H2O) within 3 hours of intubation. Unadjusted clinical predictors of in-hospital mortality included age (unit odds ratio, 1.05; 1.01–1.10; p = 0.015), time from admission to intubation (hr) (unit odds ratio, 1.01; 1.01–1.03; p = 0.017), and use of paralytics (relative risk, 1.54; 1.26–1.90, p < 0.001). Adjusted mechanical ventilation-related predictors of in-hospital mortality included achieving early targeted plateau pressures (odds ratio, 0.23; 0.07–0.76; p = 0.016), PaO2/FIO2 ratio at 3 (unit odds ratio, 0.98; 0.96–0.99, p = 0.002) and 48 hours (unit odds ratio, 0.98; 0.97–0.99, p = 0.018), initial mean airway pressure (unit odds ratio, 1.13; 1.02–1.28, p = 0.019), and total net fluid status (mL) (unit odds ratio, 1.01; 1.001–1.02, p = 0.0001).
CONCLUSIONS:Several factors predict in-hospital mortality in fibrotic interstitial lung disease-associated mechanical ventilation when viewed through an acute respiratory distress syndrome model. Further research is needed to refine strategies that may perhaps improve survival if mechanical ventilation is pursued in this set of patients.
Single‐molecule electronic components (SMECs) are envisioned as next‐generation building blocks in quantum circuit systems. However, challenges such as the reproducibility of the electrode attachment ...to the individual molecules hamper their fundamental investigation. For our purpose, we introduced quasi optoelectronic electrodes (QOEs) that allow for rapid investigations of the properties and suitability of compounds for molecular electronic devices. In particular, we probed hexa‐peri‐hexabenzocoronene (HBC) as a model system for D6h‐symmetrical nanographenes, with porphyrins as QOEs attached to the periphery. We prepared selectively bis‐porphyrin‐functionalized HBCs with ortho‐, meta‐ and para‐substitution and studied their communication properties, in correlation to the geometrical alignment and size of the system, by electrochemistry and optical spectroscopy. Further insights into structure–property relationships were gained by DFT calculations and X‐ray diffraction analysis.
Clear communication: Hexabenzocoronene was utilized as a model system for nanographenes and probed spectroscopically through peripherally attached porphyrins that served as quasi optical electrodes. Nanographenes functionalized selectively in the ortho‐, meta‐, and para‐positions showed differences in the electronic communication between the porphyrins, which is reflected by a distortion of the B‐band.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Porphyrin–hexabenzocoronene architectures serve as good model compounds to study light‐harvesting systems. Herein, the synthesis of porphyrin functionalized hexa‐peri‐hexabenzocoronenes (HBCs), in ...which one or more porphyrins are covalently linked to a central HBC core, is presented. A series of hexaphenylbenzenes (HPBs) was prepared and reacted under oxidative coupling conditions. The transformation to the respective HBC derivatives worked well with mono‐ and tri‐porphyrin‐substituted HPBs. However, if more porphyrins are attached to the HPB core, Scholl oxidations are hampered or completely suppressed. Hence, a change of the synthetic strategy was necessary to first preform the HBC core, followed by the introduction of the porphyrins. All products were fully characterized, including, if possible, single‐crystal XRD. UV/Vis absorption spectra of porphyrin‐HBCs showed, depending on the number of porphyrins as well as with respect to the substitution pattern, variations in their spectral features with strong distortions of the porphyrins’ B‐band.
Hexabenzocoronenes (HBCs), functionalized with up to six porphyrins, were prepared and studied. UV/Vis absorption spectroscopy showed variations in the spectral characteristics depending on the number of porphyrins as well as their respective substitution pattern. Insight into solid‐state behavior was obtained by X‐ray crystal structures.
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The extension of the aromatic π‐system of porphyrins is a powerful method to alter their optoelectronic properties. Herein, aryl substituents were fused to porphyrin cores by Scholl oxidation ...reactions that selectively produced mono‐ and doubly‐fused porphyrins in yields of up to 69 %. Several different aryl substituents attached to the porphyrin were investigated with respect to their reactivity under Scholl conditions. The fused products were fully characterized, i.e., by UV/Vis absorption spectroscopy, which showed drastic changes in the electronic features. Insight into the solid‐state behavior was obtained by X‐ray crystallography. Our approach represents a novel option for the late‐stage functionalization of porphyrin‐based compounds.
The transformation of A4‐symmetric nickel porphyrins to the respective π‐extended derivatives via a Scholl oxidative route is presented. Different meso‐aryl substituents were successfully fused to the porphyrin core using standard Scholl conditions. The photophysical characteristics of fused‐porphyrins were significantly different to the non‐fused derivatives. Insight into the solid‐state properties was obtained by X‐ray crystallography.
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Mixed cyclotrimerization reactions of diarylacetylenes (tolans) were applied to generate a library of multiple porphyrin–hexaphenylbenzene (HPB) architectures. Successful reactions, which could be ...influenced by the ratio of tolan starting materials, were conducted using dicobaltoctacarbonyl as a catalyst. Separation of the reaction products was performed by chromatographic and crystallization techniques. The physical properties were investigated with respect to the number of porphyrins per HPB and their substitution pattern.
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IJS, KILJ, NUK, PNG, UL, UM
Capacitor discharge welding primarily applies to projection welding. Components with ring projections up to 200 mm diameter can be welded with peak currents up to 1000 kA and welding times less than ...10 ms. Weld nuggets are expected to occur, as the CD-Welding belongs to resistance welding. Although the required strength is given, welding nuggets in cross-sections cannot invariably be verified. According to recent researches, joining occurs without a welding nugget, but with metal vaporisation and linked activation of the surfaces. This process is called short-time welding with high thermal current density. The type of the welded joint depends on the heating properties in the weld zone. Different welding energies, electrode forces and welding times result in different welded joints. The process-specific advantages can be taken, and new application areas for CD welding can be developed by knowing the cause-and-effect relationships.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Invasive fungal infections are associated with high morbidity in solid organ transplant recipients. Risk factor modification may help with preventative efforts. The objective of this study was to ...identify risk factors for the development of fungal infections within the first year following solid organ transplant.
We searched for eligible articles through February 3, 2023. Studies published after January 1, 2001, that pertained to risk factors for development of invasive fungal infections in solid organ transplant were reviewed for inclusion. Of 3087 articles screened, 58 were included. Meta-analysis was conducted using a random-effects model to evaluate individual risk factors for the primary outcome of any invasive fungal infections and invasive candidiasis or invasive aspergillosis (when possible) within 1 y posttransplant.
We found 3 variables with a high certainty of evidence and strong associations (relative effect estimate ≥ 2) to any early invasive fungal infections across all solid organ transplant groups: reoperation (odds ratio OR, 2.92; confidence interval CI, 1.79-4.75), posttransplant renal replacement therapy (OR, 2.91; CI, 1.87-4.51), and cytomegalovirus disease (OR, 2.97; CI, 1.78-4.94). Both posttransplant renal replacement therapy (OR, 3.36; CI, 1.78-6.34) and posttransplant cytomegalovirus disease (OR, 2.81; CI, 1.47-5.36) increased the odds of early posttransplant invasive aspergillosis. No individual variables could be pooled across groups for invasive candidiasis.
Several common risk factors exist for the development of any invasive fungal infections in solid organ transplant recipients. Additional risk factors for invasive candidiasis and aspergillosis may be unique to the pathogen, transplanted organ, or both.
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