Chemistry with Photons, Protons, and Electrons

This is an account of the research activities of our group during the first two years of its existence. First results from our work on proton-coupled electron transfer and long-range charge tunneling reactions are presented. This includes a hydrogen-bonded cation–anion pair in which a proton-coupled electron transfer process can be phototriggered and followed by simple optical spectroscopic means, as well as a series of rigid rod-like donor-bridge-acceptor molecules which we use to investigate physical phenomena associated with the tunneling of electrons or holes. A unifying feature of this research is the use of light (photons) to induce proton and/or electron transfer

A single dose of the Biontech/Pfizer BNT162b2 vaccine protected elderly residents from severe COVID‐19 during a SARS‐coronavirus‐2 outbreak in a senior citizen home in Germany

Background: A total of 62/66 (93.9%) residents in a senior citizen home in Bremen, Germany, received the first dose of the Biontech/Pfizer vaccine BNT162b2 on December 27th 2020. After routine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen tests showed positive results on January 5th, all residents and staff were tested by RT-PCR. Results: Nine staff members and 23 residents had a positive result. PCR positive staff members reported mild to severe COVID-19 symptoms, one was hospitalized. None of them had been vaccinated. In contrast, the vaccinated residents reported no or only mild symptoms. Sequencing of the SARS-CoV-2 genomes of infected individuals revealed a monophyletic origin of the outbreak within the PANGO lineage B.1.177.86. Conclusions: In summary, our data show that partial vaccination prevented severe COVID-19 among the residents during this local SARS-CoV-2 outbreak, suggesting a high effectiveness of even a single vaccine dose, but also emphasize that asymptomatic individuals might still be carriers/spreaders

Endoscopic treatment of prepatellar bursitis

Operative treatment of prepatellar bursitis is indicated in intractable bursitis. The most common complication of surgical treatment for prepatellar bursitis is skin problems. For traumatic prepatellar bursitis, we propose a protocol of outpatient endoscopic surgery under local anaesthesia. From September 1996 to February 2001, 60 cases of failed nonoperative treatment for prepatellar bursitis were included. The average age was 33.5 ± 11.1 years (range 21–55). The average operation duration was 18 minutes. Two to three mini-arthroscopic portals were used in our series. No sutures or a simple suture was needed for the portals after operation. After follow-up for an average of 36.3 months, all patients are were symptom-free and had regained knee function. None of the population had local tenderness or hypo-aesthesia around their wound. Their radiographic and sonographic examinations showed no recurrence of bursitis. Outpatient arthroscopic bursectomy under local anaesthesia is an effective procedure for the treatment of post-traumatic prepatellar bursitis after failed conservative treatments. Both the cosmetic results and functional results were satisfactory

Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

High-resolution anorectal manometry: A comparison of solid-state and water-perfused catheters.

BACKGROUND: Anorectal manometry is the most commonly performed investigation for assessment of anorectal dysfunction. Findings from previous studies comparing water-perfused (WP) and solid-state (SS) techniques in the anorectum are conflicting. We compared anal sphincter pressure at rest and during dynamic maneuvers (squeezing and coughing) in healthy volunteers using SS and WP high-resolution anorectal manometry (HR-ARM) employing equivalent catheter configurations, a standardized protocol, and identical data acquisition and analysis software. METHODS: Sixty healthy volunteers (40F; median age: 40; range: 18-74) underwent WP and SS HR-ARM in randomized order. Anal resting pressure, and squeeze and cough increments were measured. Median pressure and 5th and 95th percentiles were calculated for each maneuver and compared using Wilcoxon signed-rank test. Bland and Altman plots were used to assess agreement between the systems. The impact of gender and parity was also explored. KEY RESULTS: Anal sphincter pressure measurements during squeeze (P<.001) and cough (P<.001) were significantly higher using SS HR-ARM than WP HR-ARM. No differences were seen at rest between the two types of catheter (nulliparous: P=.304; parous: P=.390; males: P=.167). Normal ranges for SS and WP manometry from this small group of healthy volunteers are presented. CONCLUSIONS & INFERENCES: Greater sensitivity to rapid pressure change is one of the advantages associated with SS HR-ARM. This is reflected in the differences observed during dynamic maneuvers performed during this study. Catheter type should be taken into consideration when selecting normal ranges for comparison to disease states.Funding for the water-perfused catheters and volunteer payments was provided by Ardmore Healthcare Ltd and Medical Measurement Systems

Ruthenium(II)-Pyridylimidazole Complexes as Photoreductants and PCET Reagents

Complexes of the type [Ru(bpy)2pyimH]2+ [bpy = 2,2′‐bipyridine; pyimH = 2‐(2‐pyridyl)imidazole] with various substituents on the bpy ligands can act as photoreductants. Their reducing power in the ground state and in the long‐lived 3MLCT excited state is increased significantly upon deprotonation, and they can undergo proton‐coupled electron transfer (PCET) in the ground and excited state. PCET with both the proton and electron originating from a single donor resembles hydrogen atom transfer (HAT) and can be described thermodynamically by formal bond dissociation free energies (BDFEs). Whereas the class of complexes studied herein has long been known, their N–H BDFEs have not been determined even though this is important in view of assessing their reactivity. Our study demonstrates that the N–H BDFEs in the 3MLCT excited states are between 34 and 52 kcal mol–1 depending on the chemical substituents at the bpy spectator ligands. Specifically, we report on the electrochemistry and PCET thermochemistry of three heteroleptic complexes in 1:1 (v/v) CH3CN/H2O with CF3, tBu, and NMe2 substituents on the bpy ligands

Transfert de charges et d'énergie dans différents systèmes moléculaires excités comportant un métal de transition d6

Ces dernières années dans le domaine de la chimie, une des recherches les plus en vogue est le développement de systèmes moléculaires simples pouvant mimer les propriétés existant dans les systèmes naturels, comme par exemple les propriétés de transferts de charges du photosystème II, lors de la photosynthèse des plantes. Dans ce travail de thèse, il a été entrepris la synthèse et l'étude de nouveaux systèmes comportant un métal de transition d6 pouvant entraîner un transfert photo-induit de charges où d'énergie à travers des liaisons covalentes où non-covalentes. Ces modèles sont étudiés de manières photochimique et électrochimique pour permettre une meilleure compréhension du phénomène de transfert, des effets liés aux substituants présents dans ces systèmes et ainsi d'utiliser des outils simples de spectroscopie pour déterminer ces propriétés. Ce travail mélange synthèse organique/inorganique et étude du comportement des métaux de transition, lors du transfert de charges où d'électron