Silicon color centers have recently emerged as promising candidates for commercial quantum technology, yet their interaction with electric fields has yet to be investigated. In this paper, we demonstrate electrical manipulation of telecom silicon color centers by implementing novel lateral electrical diodes with an integrated G center ensemble in a commercial silicon on insulator wafer. The ensemble optical response is characterized under application of a reverse-biased DC electric field, observing both 100% modulation of fluorescence signal, and wavelength redshift of approximately 1.
View Article and Find Full Text PDFBackground: Serial neurological examinations (NEs) are routinely recommended in the intensive care unit (ICU) within the first 24 hours following a traumatic brain injury (TBI). There are currently no widely accepted guidelines for the frequency of NEs. Disruptions to the sleep-wake cycles increase the delirium rate.
View Article and Find Full Text PDFLudwig's angina (LA) is a diffuse cellulitis of the submandibular space and adjacent tissues. During the coronavirus disease 2019 (COVID-19) pandemic, odontogenic treatments were often delayed because of the implementation of safety measures to avoid the spread of the virus. We hypothesized that delayed odontogenic treatments associated with the onset of the COVID-19 pandemic would be associated with an increase in the incidence of LA and worse outcomes related to these infections.
View Article and Find Full Text PDFHigh-yield engineering and characterization of cavity-emitter coupling is an outstanding challenge in developing scalable quantum network nodes. Ex situ defect formation systems prevent real-time analysis, and previous in situ methods are limited to bulk substrates or require further processing to improve the emitter properties. Here we demonstrate the direct laser writing of cavity-integrated spin defects using a nanosecond pulsed above-bandgap laser.
View Article and Find Full Text PDFA simple method for the C-4 alkylation of isoquinolines is described using benzoic acid as a nucleophilic reagent and vinyl ketones as an electrophile. The reaction shows tolerance for substitution at C-3, and C-5-C-8 positions as well as allowing some variation of the vinyl ketone electrophiles. The products contain a carbonyl that can act as a synthetic handle for further manipulations giving esters, amines, or simple alkyl products.
View Article and Find Full Text PDFThe total synthesis of (-)-γ-lycorane (10 steps) and synthesis of (±)-γ-lycorane (8 steps) was completed from cyclohexenone. A new two step hydrogen borrowing alkylation of an aziridinyl alcohol, coupled with a Ph* (MeC) deprotection/cyclisation procedure was developed for formation of the fused 6,5 heterocyclic ring. This work is one of the first examples of hydrogen borrowing C-C bond formation being used as a key step in a total synthesis project.
View Article and Find Full Text PDFOxidative degradation and rearrangement of polycyclic polyprenylated acylphloroglucinols (PPAPs) has created diverse families of unique natural products that are attractive targets for biomimetic synthesis. Herein, we report a racemic synthesis of hyperibrin A and its oxidative radical cyclization to give yezo'otogirin C, followed by epoxidation and House-Meinwald rearrangement to give hypermogin D. We also investigated the biomimetic synthesis of norascyronone A a similar radical cyclization pathway, with unexpected results that give insight into its biosynthesis.
View Article and Find Full Text PDFComplement activation has been implicated in the pathogenesis of severe SARS-CoV-2 infection. However, it remains to be determined whether increased complement activation is a broad indicator of critical illness (and thus, no different in COVID-19). It is also unclear which pathways are contributing to complement activation in COVID-19, and if complement activation is associated with certain features of severe SARS-CoV-2 infection, such as endothelial injury and hypercoagulability.
View Article and Find Full Text PDFInfection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or seasonal influenza may lead to respiratory failure requiring intubation and mechanical ventilation. The pathophysiology of this respiratory failure is attributed to local immune dysregulation, but how the immune response to viral infection in the lower airways of the human lung differs between individuals with respiratory failure and those without is not well understood. We used quantitative multiparameter flow cytometry and multiplex cytokine assays to evaluate matched blood and bronchoalveolar lavage (BAL) samples from control human subjects, subjects with symptomatic seasonal influenza who did not have respiratory failure, and subjects with severe seasonal influenza or SARS-CoV-2 infection with respiratory failure.
View Article and Find Full Text PDFComplement activation has been implicated in the pathogenesis of severe SARS-CoV-2 infection. However, it remains to be determined whether increased complement activation is a broad indicator of critical illness (and thus, no different in COVID-19). It is also unclear which pathways are contributing to complement activation in COVID-19, and, if complement activation is associated with certain features of severe SARS-CoV-2 infection, such as endothelial injury and hypercoagulability.
View Article and Find Full Text PDFProlonged shedding of viral RNA occurs in some individuals following SARS-CoV-2 infection. We perform comprehensive immunologic evaluation of one individual with prolonged shedding. The case subject recovered from severe COVID-19 and tested positive for SARS-CoV-2 viral RNA repeatedly as many as 87 days after the first positive test, 97 days after symptom onset.
View Article and Find Full Text PDFTotal synthesis of the meroterpenoids rubiginosins A and G, which both contain unusual 6-6-6-4 ring systems, has been achieved using a bioinspired cascade approach. Stepwise synthesis of these natural products, and the related 6-6-5-4 meroterpenoids fastinoid B and rhodonoid B, from naturally occurring chromene precursors is also reported.
View Article and Find Full Text PDFReinvestigation of the coumarin meroterpenoids of using pressurized hot water extraction (PHWE) procedures led to the isolation of prenylbruceol A, a proposed biosynthetic precursor of seven previously reported bruceol derivatives, prenylbruceols B-H. Protobruceol-I, ostruthin, dipetalactone, and a new dihydrocoumarin natural product were isolated alongside prenylbruceol A. A biomimetic singlet oxygen ene reaction of prenylbruceol A allowed the semisynthesis of prenylbruceols B, C, and D.
View Article and Find Full Text PDFBackground: Cellular immune responses are not well characterized during the initial days of acute symptomatic influenza infection.
Methods: We developed a prospective cohort of human subjects with confirmed influenza illness of varying severity who presented within a week after symptom onset. We characterized lymphocyte and monocyte populations as well as antigen-specific CD8+ T-cell and B-cell responses from peripheral blood mononuclear cells using flow cytometry and enzyme-linked immunospot assays.
A biomimetic approach to total synthesis can offer several benefits, including the development of cascade reactions for the rapid generation of molecular complexity, and guidance in the structure revision of old natural products and the anticipation of new ones. Herein, we describe how a biomimetic synthesis of bruceol, a pentacyclic meroterpenoid, led to the anticipation, isolation, and synthesis of isobruceol. The key step in the synthesis of both bruceol and isobruceol was an intramolecular hetero-Diels-Alder reaction of an -quinone methide that was formed by dearomatization of an electron-rich chromene.
View Article and Find Full Text PDFThe total synthesis of nyingchinoids A and B has been achieved through successive rearrangements of a 1,2-dioxane intermediate that was assembled using a visible-light photoredox-catalysed aerobic [2+2+2] cycloaddition. Nyingchinoid D was synthesised with a competing [2+2] cycloaddition. Based on NMR data and biosynthetic speculation, we proposed a structure revision of the related natural product rasumatranin D, which was confirmed through total synthesis.
View Article and Find Full Text PDFThe first total synthesis of bruceol has been achieved using a biomimetic cascade cyclization initiated by a stereoselective Jacobsen-Katsuki epoxidation (and kinetic resolution) of racemic protobruceol-I. A bacterial cytochrome P450 monooxygenase was also found to catalyze the conversion of protobruceol-I into bruceol. The first full analysis of the NMR data of natural bruceol suggested that "isobruceol" was a previously unrecognized natural product also isolated from Philotheca brucei.
View Article and Find Full Text PDFA divergent, three-step total synthesis of rhodonoids C and D has been achieved using a biosynthetically inspired, acid-catalyzed cascade cyclization of an epoxy-chromene that involves the presumed intermediacy of o-quinone methides. Application of a similar strategy also allowed synthesis of the alkaloid murrayakonine D.
View Article and Find Full Text PDFDecreased HDL-cholesterol (HDL-C) and familial combined hyperlipidemia (FCHL) are the two most common familial dyslipidemias predisposing to premature coronary heart disease (CHD). These dyslipidemias share many phenotypic features, suggesting a partially overlapping molecular pathogenesis. This was supported by our previous pooled data analysis of the genome scans for low HDL-C and FCHL, which identified three shared chromosomal regions for a qualitative HDL-C trait on 8q23.
View Article and Find Full Text PDF