Publications by authors named "Robert Walter"

Targeted perioperative therapeutics supporting anastomotic healing during colitis are an urgent medical need. This study aimed to develop and evaluate a novel nanoparticle (NP)-based drug delivery system for improving anastomotic healing in Inflammatory bowel disease (IBD) patients following surgery. We developed pectin-coated polymeric NPs encapsulating the inflammation-resolving peptide Ac2-26.

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Introduction: Asthma is the most common diagnosis in military personnel who endorse chronic dyspnea. Service members have unique occupational risk factors, and there is concern that airborne exposures in the deployed environment as well as other occupational exposures may contribute to the development of asthma or exacerbate pre-existing disease. Asthma phenotyping with clinical biomarkers such as serum immunoglobulin E (IgE) levels and eosinophil (EOS) counts is useful in defining treatment strategies for the management of asthma.

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Article Synopsis
  • - The study focuses on the synthesis and complexation of ferrocenyl-substituted mesoionic imines (MIIs), highlighting strong hydrogen bonding between their components in both solid and solution states.
  • - Uniquely, the complexation with [IrCp*Cl] leads to the formation of rare six-membered iridacycles, driven by C-H activation at the ferrocenyl group, contrary to expectations based on previous findings.
  • - The research also explores how variations in solvent polarity and the resulting interactions can significantly alter the properties of the resulting iridium complexes, as well as examining their redox behavior through various methods.
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Air-stable dinuclear complexes [(bmsab)Ni(tmsab)Ni(bmsab)] and [(bmsab)Zn(tmsab)Zn(bmsab)] (bmsab = bis(methanesulfoneamido)benzene, tmsab = tetra(methanesulfonamido)benzene) were prepared via a synthetic route based on heteroleptic precursor complexes. The new complexes combine a distorted tetrahedral coordination environment with an open-shell bridging ligand. The Zn species was subjected to a detailed investigation of the (spectro-)electrochemical processes.

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Introduction: Deployed military personnel may be at risk for developing acute and chronic lung disease. Prior studies of this patient population have revealed that unexplained exertional dyspnea is the most common diagnosis despite an extensive evaluation. There is a concern that an occult disorder may be affecting this population.

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Study Objectives: Despite the efficacy of positive airway pressure (PAP) for the treatment of obstructive sleep apnea, adherence remains challenging and negatively affects assessments of effectiveness. It is unclear whether low adherence is due to intolerance of PAP or whether this reflects overall adherence with medical therapy. We sought to correlate PAP use with medication adherence to determine whether poor adherence with PAP was specific to this treatment or represented global compliance with medical therapy.

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Topic Importance: The global surge in methamphetamine use is a critical public health concern, particularly due to its robust correlation with methamphetamine-associated pulmonary arterial hypertension (MA-PAH). This association raises urgent alarms about the potential escalation of MA-PAH incidence, posing a significant and imminent challenge to global public health.

Review Findings: This comprehensive review meticulously explores MA-PAH, offering insights into its epidemiology, pathophysiology, clinical presentation, diagnostic intricacies, and management strategies.

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Objective: This study compares the clinical and haemodynamic severity of methamphetamine-associated pulmonary arterial hypertension (MA-PAH) with idiopathic pulmonary arterial hypertension (IPAH) and connective tissue-associated pulmonary arterial hypertension (CTD-PAH). It also examines sex differences in clinical and physiological parameters among those with MA-PAH.

Design: This is a cross-sectional study using clinically derived data from the National Biological Sample and Data Repository for Pulmonary Arterial Hypertension (PAH biobank), a US-based registry, to compare clinical and physiological characteristics between males and females with MA-PAH.

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In recent years, metal complexes of pyridyl-mesoionic carbene (MIC) ligands have been reported as excellent homogeneous and molecular electrocatalysts. In combination with group 9 metals, such ligands form highly active catalysts for hydrogenation/transfer hydrogenation/hydrosilylation catalysis and electrocatalysts for dihydrogen production. Despite such progress, very little is known about the structural/electrochemical/spectroscopic properties of crucial intermediates for such catalytic reactions with these ligands: solvato complexes, reduced complexes and hydridic species.

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Invited for the cover of this issue are Biprajit Sarkar and co-workers at the University of Stuttgart and University of Freiburg. In the image, the solar flare represents the non-innocence (fluorine-specific interactions) of the counterion, and the black hole at the metal center illustrates the oxidation/electron deficiency of the Cr-center, while the electron "gets lost" in the space (oxidation agent). Read the full text of the article at 10.

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The exact mechanism of desmoplastic stromal reaction (DSR) formation is still unclear. The interaction between cancer cells and cancer-associated fibroblasts (CAFs) has an important role in tumor progression, while stromal changes are a poor prognostic factor in pleural mesothelioma (PM). We aimed to assess the impact of CAFs paracrine signaling within the tumor microenvironment and the DSR presence on survival, in a cohort of 77 PM patients.

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We present here new synthetic strategies for the isolation of a series of Ru(II) complexes with pyridyl-mesoionic carbene ligands (MIC) of the 1,2,3-triazole-5-ylidene type, in which the bpy ligands (bpy = 2,2'-bipyridine) of the archetypical [Ru(bpy)] have been successively replaced by one, two, or three pyridyl-MIC ligands. Three new complexes have been isolated and investigated via NMR spectroscopy and single-crystal X-ray diffraction analysis. The incorporation of one MIC unit shifts the potential of the metal-centered oxidation about 160 mV to more cathodic potential in cyclic voltammetry, demonstrating the extraordinary σ-donor ability of the pyridyl-MIC ligand, while the π-acceptor capacities are dominated by the bpy ligand, as indicated by electron paramagnetic resonance spectroelectrochemistry (EPR-SEC).

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Article Synopsis
  • Critical Care Internal Medicine (CCIM) is essential for the U.S. Military, particularly highlighted during the COVID-19 pandemic and in wartime, yet research on the specific needs for military CCIM physicians remains limited.
  • This study aimed to compare the patient volume and severity of cases seen by military CCIM physicians working solely at Military Treatment Facilities (MTFs) versus those also involved in a military-civilian partnership at a university medical center.
  • Results showed that the five AF CCIM physicians in the partnership managed 2,019 critical care encounters in 206 days, with a higher percentage (63.1%) of those classified as high acuity compared to overall MTF encounters (28.9%) and CCIM
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The Cooling to Help Injured Lungs (CHILL) trial is an open label, two group, parallel design multicenter, randomized phase IIB clinical trial assessing the efficacy and safety of targeted temperature management with combined external cooling and neuromuscular blockade to block shivering in patients with early moderate-severe acute respiratory distress syndrome (ARDS). This report provides the background and rationale for the clinical trial and outlines the methods using the Consolidated Standards of Reporting Trials guidelines. Key design challenges include: [1] protocolizing important co-interventions; [2] incorporation of patients with COVID-19 as the cause of ARDS; [3] inability to blind the investigators; and [4] ability to obtain timely informed consent from patients or legally authorized representatives early in the disease process.

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Article Synopsis
  • The study introduces stable and crystalline chromium(I) tetracarbonyl complexes that utilize pyridyl-MIC ligands along with weakly coordinating anions (WCAs), which include specific aluminum and boron derivatives.
  • Comprehensive characterization of these complexes was achieved through crystallographic, spectroscopic, and theoretical methods, with a focus on how counter anions affect IR and EPR spectroscopic properties.
  • This research marks the first instance of such stable chromium complexes with a chelating ligand, contributing valuable insights into their photochemical and electrochemical behaviors.
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Background: Limited hospital inpatient capacity, exacerbated by SARS-CoV-2 (COVID-19) and associated staffing shortages, has driven interest in converting surgeries historically done as inpatient procedures to same-day surgeries (SDS). Remote patient monitoring (RPM) has the potential to increase safety and confidence in SDS but has had mixed success in a bariatric population.

Objectives: Assess the feasibility of and adherence to a protocol offering patients same-day laparoscopic sleeve gastrectomy (SG) supported by RPM with an updated wearable device.

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Two homoleptic Fe(II) complexes in different spin states bearing superbasic terpyridine derivatives as ligands are investigated to determine the relationship between spin state and electrochemical/spectroscopic behavior. Antiferromagnetic coupling between a ligand-centered radical and the high-spin metal center leads to an anodic shift of the first reduction potential and results in a species that shows mixed valency with a moderately intense intervalence-charge-transfer band. The differences afforded by the different spin states extend to the electrochemical reactivity of the complexes: while the low-spin species is a precatalyst for electrocatalytic CO reduction and leads to the preferential formation of CO with a Faradaic efficiency of 37%, the high-spin species only catalyzes proton reduction at a modest Faradaic efficiency of approximately 20%.

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Article Synopsis
  • Mesoionic carbenes (MICs) are gaining attention in research for their potential in stabilizing radicals and cationic forms, areas that haven’t been thoroughly explored yet.
  • The study focuses on synthesizing three azide-substituted 1,2,3-triazolium salts to investigate their reactivity with triphenylphosphine, finding that this reactivity varies based on the specific triazolium salt used.
  • The research also shows that cationic triazolium salts can be transformed into radical forms that exhibit unique properties, with MICs proving crucial in stabilizing these radicals compared to their NHC counterparts, providing new insights into
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In recent years terpyridines (tpy) and mesoionic carbenes (MIC) have been widely used in metal complexes. With the right combination with a metal center, both of these ligands are individually known to generate excellent catalysts for CO reduction. In this study, we combine the potentials of PFC (PFC=polyfluorocarbon) substituted tpy and MIC ligands within the same platform to obtain a new class of complexes, which we investigated with respect to their structural, electrochemical and UV/Vis/NIR spectroelectrochemical properties.

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Introduction: Coronavirus disease 2019 (COVID-19) infection is characterized by a dysregulated inflammatory response, which may result in severe hemodynamic instability and septic shock. The Seraph-100® Microbind® Affinity Blood Filter is a commercially available extracorporeal pathogen absorbent device with the ability to bind pathogens and cytokines present within the blood. Our study aimed to evaluate the efficacy of the Seraph-100® for patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and septic shock.

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Background: Virtual care (VC) and remote patient monitoring programs were deployed widely during the COVID-19 pandemic. Deployments were heterogeneous and evolved as the pandemic progressed, complicating subsequent attempts to quantify their impact. The unique arrangement of the US Military Health System (MHS) enabled direct comparison between facilities that did and did not implement a standardized VC program.

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Diamidobenzene ligands are a prominent class of redox-active ligands owing to their electron reservoir behaviour, as well as the possibility of tuning the steric and the electronic properties of such ligands through the substituents on the N-atoms of the ligands. In this contribution, we present Rh(iii) complexes with four differently substituted diamidobenzene ligands. By using a combination of crystallography, NMR spectroscopy, electrochemistry, UV-vis-NIR/EPR spectroelectrochemistry, and quantum chemical calculations we show that the substituents on the ligands have a profound influence on the bonding, donor, electrochemical and spectroscopic properties of the Rh complexes.

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Introduction: Pulmonary embolism (PE) is associated with significant rates of morbidity and mortality. Management of PE is complex, and adverse patient events are not uncommon. Brooke Army Medical Center (BAMC) is among several select institutions that have implemented multidisciplinary pulmonary embolism response teams (PERTs) to improve PE outcomes.

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In intermediate risk hormone receptor (HR) positive, HER2 negative breast cancer (BC), the decision regarding adjuvant chemotherapy might be facilitated by multigene expression tests. In all, 142 intermediate risk BCs were investigated using the PAM50-based multigene expression test Prosigna® in a prospective multicentric study. In 119/142 cases, Prosigna® molecular subtyping was compared with local and two central (C1 and C6) molecular-like subtypes relying on both immunohistochemistry (IHC; HRs, HER2, Ki-67) and IHC + tumor grade (IHC+G) subtyping.

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There are limited data on the treatment of fungal infections complicating extracorporeal membrane oxygenation (ECMO). In 14 patients who developed fungal bloodstream infections on ECMO, 8 (57%) survived to discharge. Of the 5 patients completing treatment prior to decannulation, 2 (40%) developed recurrent fungal infections.

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