Publications by authors named "Champagne P"

Unlabelled: One common gait issue associated with advanced Parkinson's disease (PD) is freezing of gait (FoG). FoG impacts approximately half of people with PD and negatively impacts quality of life. Studies have suggested that anxiety may contribute to FoG.

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Latex-based nanocomposites containing carboxylated cellulose nanocrystals (cCNCs) were synthesized via in situ seeded semibatch emulsion polymerization. Inspired by nature's use of CNCs to enhance rigidity and mechanical strength in cellulosic materials, we explored similar principles to improve the properties of acrylate water-based coatings. The cCNCs, loaded at 0.

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Article Synopsis
  • - The study investigates the role of pathological dural invasion (pathDI) as a predictor for neck metastases and recurrence in patients with olfactory neuroblastoma (ONB), using data from a multicenter database of ONB cases collected between 2005 and 2021.
  • - Among the 258 patients reviewed, those with pathDI had a significantly lower 10-year neck recurrence-free survival (61.8%) compared to those without it (85.7%), indicating a strong negative impact of pathDI on prognosis.
  • - The analysis revealed that pathDI is a significant predictor of neck recurrence and recurrence at other sites, suggesting that future research could lead to changes in treatment strategies for patients with pathDI. *
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Traumatic optic neuropathy (TON) consists of damage to the optic nerve following head injury and affects about 0.5-5% of patients with closed head injuries. It is characterized by a sudden decrease in visual acuity and/or visual field loss.

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-Nitrosocumene (-NC) exhibits dynamic N,N bonding, interchanging monomer and /-azodioxide dimer structures, the extent of which depends on the environment. As a solid, -NC is a Z-dimer; in organic solvent, the monomer is favored; and in water, dimers are favored. A supramolecular assembly of -NC is observed as a separate species by NMR in water, shown to be a novel nanometer-sized aggregate containing ∼2000 molecules.

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Background: The upper respiratory mucosa plays a crucial role in both the physical integrity and immunological function of the respiratory tract. However, in certain situations such as infections, trauma, or surgery, it might sustain damage. Tissue engineering, a field of regenerative medicine, has found applications in various medical fields including but not limited to plastic surgery, ophthalmology, and urology.

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Background And Objectives: Endoscopic endonasal surgery is a well-established surgical approach to the skull base. Surgeons need a reusable long-lasting tool to acquire the skills needed for skull base reconstruction. The aim of this study was to elaborate and validate a human formalin-fixed cadaveric model that reproduces a realistic cerebrospinal fluid (CSF) circulation and that adequately renders a CSF leak.

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Article Synopsis
  • Persulfides (RSSH) are reactive sulfur species that naturally occur in the body, protecting important cysteine residues from oxidation and participating in various enzymatic processes.
  • They can act as either nucleophiles or electrophiles, with their reactivity influenced by surrounding chemical conditions, leading to different pathways like HS release or transpersulfidation.
  • The research combines computational analysis and experimental methods to reveal how factors like steric bulk and electron withdrawal affect persulfide reactivity, showcasing the first direct observation of transpersulfidation in small molecules.
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Article Synopsis
  • - The Gewald reaction is a method for creating 2-aminothiophenes using carbonyl compounds, activated acetonitriles, and sulfur, but its mechanism is not fully understood, leading to a study using density functional theory (DFT) to explore the decomposition of sulfur and polysulfide intermediates.
  • - The reaction starts with a Knoevenagel-Cope condensation and involves the opening of sulfur to form polysulfides, which can interconvert or decompose through several mechanisms, including protonation that alters their reactivity.
  • - Despite various pathways for decomposition, none provide thermodynamic advantages, leading to a mix of polysulfide lengths in solution, with the only driving force being the cyclization
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Introduction: Surgical techniques for sellar reconstruction include no reconstruction, use of synthetic materials, autologous grafts, and/or vascularized flaps. The aim of this study was to conduct a multi-center study comparing the efficacy and postoperative morbidity associated with different sellar reconstruction techniques.

Methods: A retrospective chart review of patients who underwent endoscopic transsphenoidal surgery for pituitary tumors from five participating sites between January 2021 and March 2023 was performed.

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Introduction: Standard treatment of a juvenile angiofibroma (JNA) is surgical resection, usually with an endoscopic endonasal surgery and a preoperative embolization. However, standard intra-arterial embolization may fail to completely devascularize tumors. A novel technique of direct intranasal intratumoral onyx embolization has been described.

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The cyclopropylcarbinyl (CPC) and bicyclobutonium (BCB) structures of the CH cation have been proposed as intermediates in various reactions forming cyclopropylcarbinyl, cyclobutyl, or homoallyl products. While these cations can react with nucleophiles stereospecifically, in each system there are usually multiple BCB/CPC cations in equilibrium with related cyclobutyl (CB) and homoallyl (HA) cations, from which stereospecificity is jeopardized. Using density functional theory (DFT) and DLPNO-CCSD(T) calculations, we studied the electronic and steric effects on the equilibria between mono- and polysubstituted CH cations.

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Different cellulose nanocrystal (CNC) forms (dried vs never-dried) can lead to different degrees of CNC reassembly, the formation of nanofibril-like structures, in nanocomposite latex-based pressure-sensitive adhesive (PSA) formulations. CNC reassembly is also affected by CNC sonication and loading as well as the protocol used for CNC addition to the polymerization. In this study, carboxylated CNCs (cCNCs) were incorporated into a seeded, semibatch, 2-ethylhexyl acrylate/methyl methacrylate/styrene emulsion polymerization and cast as pressure-sensitive adhesive (PSA) films.

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Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC), formerly known as HPV-related carcinoma with adenoid cystic like features, is a rare tumor subtype with unusual correlation between radiological, histopathological, and surgical findings. The shared histological characteristics with other sinonasal tumors make the diagnosis challenging. Optimal surgical and oncological treatments for this rare condition remains to be clearly defined.

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Background: With modern treatment paradigms, olfactory neuroblastoma (ONB) has favorable overall survival (OS); however, the incidence of recurrence remains high. The primary aims of this study were to delineate the prognosis of recurrence of ONB and explore how recurrence subsites are associated with OS, disease-specific survival (DSS), and further recurrence.

Methods: A retrospective chart review of ONB cases from nine academic centers between 2005 and 2021 was completed.

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In low-middle income countries (LMIC), wastewater treatment using native microalgal-bacterial consortia has emerged as a cost-effective and technologically-accessible remediation strategy. This study evaluated the effectiveness of six microalgal-bacterial consortia (MBC) from the Ecuadorian Amazon in removing organic matter and nutrients from non-sterilized domestic wastewater (NSWW) and sterilized domestic wastewater (SWW) samples. Microalgal-bacterial consortia growth, in NSWW was, on average, six times higher than in SWW.

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Background: The vertebral arteries (VA) play a critical role by supplying nearly one-third of the brain's blood flow, predominantly contributing to the posterior circulation. These arteries may need to be exposed in a various cranial and cervical procedures and offers access to investigate or treat vascular lesions by endovascular means related to the posterior circulation. Given its complex anatomy, which is subject to numerous variations, and its role in supplying vital brain regions, a thorough understanding of the VA's anatomy is paramount for any related procedure.

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Alkyl isothiocyanates (R-NCS) have pharmacological applications and provide a synthetic handle to various functional groups including thioureas. There are however few methods to access alkyl isothiocyanates through the creation of the C-N bond. We have developed a simple approach for the conjugate isothiocyanation of enones by trimethylsilyl isothiocyanate (TMSNCS), which proceeds through the 1,4-addition of the weak isothiocyanate nucleophile to activated enones in the absence of external promoters.

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Background: Total ankle arthroplasty (TAA) is a preferred surgical option for end-stage ankle osteoarthritis; however, it is a demanding procedure with a higher historical rate of revision compared with ankle fusion. Patient-specific instrumentation (PSI) has been introduced to optimize prosthesis alignment and theoretically overall improve TAA outcomes. The goal of this study is to report on the experience and surgical outcomes of one implant with specific evaluation of the accuracy and reproducibility of the system with respect to prosthesis alignment and prediction of implant size.

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Objective: To review a single-center experience with hearing rehabilitation in patients with neurofibromatosis type 2 (NF2) and to describe the auditory outcomes of cochlear implants (CIs) and auditory brainstem implants (ABI) in this population.

Study Design: Retrospective case series.

Setting: Tertiary referral center.

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Importance: Current olfactory neuroblastoma (ONB) staging systems inadequately delineate locally advanced tumors, do not incorporate tumor grade, and poorly estimate survival and recurrence.

Objective: The primary aims of this study were to (1) examine the clinical covariates associated with survival and recurrence of ONB in a modern-era multicenter cohort and (2) incorporate Hyams tumor grade into existing staging systems to assess its ability to estimate survival and recurrence.

Design, Setting, And Participants: This retrospective, multicenter, case-control study included patients with ONB who underwent treatment between January 1, 2005, and December 31, 2021, at 9 North American academic medical centers.

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Hydrogen selenide (HSe) is a possible bioregulator, potential gasotransmitter, and important precursor in biological organoselenium compound synthesis. Early tools for HSe research have benefitted from available mechanistic understanding of analogous small molecules developed for detecting or delivering HS. A now common approach for HS delivery is the use of small molecule thiocarbamates that can be engineered to release COS, which is quickly converted to HS by carbonic anhydrase.

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Objectives: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy.

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Pituitary apoplexy (PA) is a rare phenomenon, characterized by a hemorrhagic or ischemic event of the pituitary gland, most often in association with a pituitary lesion. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the strain of virus responsible for the internationally recognized global pandemic COVID-19. Multiple clinical manifestations associated with this virus have been described, ranging from asymptomatic, mild flu symptoms to acute respiratory distress syndrome, end-organ failure leading to death.

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The synthesis of quaternary homoallylic halides and trichloroacetates from cyclopropylcarbinols, as reported by Marek ( , , 5543-5548), is one of the few reported examples of stereospecific nucleophilic substitution involving chiral bridged carbocations. However, for the phenyl-substituted substrates, poor specificity is observed and mixtures of diastereomers are obtained. To understand the nature of the intermediates involved and explain the loss of specificity for certain substrates, we have performed a computational investigation of the reaction mechanism using ωB97X-D optimizations and DLPNO-CCSD(T) energy refinements.

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