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The skin hydration level is a key factor that influences the physical and mechanical properties of the skin. The stratum corneum (SC), the outermost layer of the epidermis, is responsible for the skin's barrier function. In this study, we investigated the role of a unique composition of Viola yedoensis extract for its ability to activate CD44, a cell-surface receptor of hyaluronic acid, and aquaporin-3, a water-transporting protein, in human keratinocytes (HaCaT). An ELISA assay evaluating the protein expression levels of CD44, aquaporin-3 (AQP3), filaggrin, and keratin-10 revealed that V. yedoensis extract upregulated the levels of CD44 and AQP3 by 15% and 78%, respectively. Additionally, V. yedoensis extract demonstrated a comparative effect on water vapor flux in TEWL and lipid perturbation in DSC versus the reference, glycerin. In light of this new biological efficacy, a detailed phytochemical characterization was undertaken using an integrated LC-HRMS/MS-based metabolomics approach, which provided further insights on the chemistry of V. yedoensis. This led to the identification of 29 secondary metabolites, 14 of which are reported here for the first time, including esculetin, aesculin, apigenin and kaempferol C-glycosides, megastigmane glycosides, roseoside, platanionoside B, and an eriojaposide B isomer, along with the rare, calenduloside F and esculetin diglucoside, which are reported for the first time from the genus, Viola. Notably, two active components identified in the V. yedoensis extract, namely, aesculin and schaftoside, showed an upregulation of the protein expression of CD44 in HaCaT cells by 123% and 193% within 24 h of treatment, respectively, while aesculin increased AQP3 levels by 46%. Aesculin and schaftoside also significantly upregulated the expression of K-10 levels by 299% and 116%, which was considerably higher than sodium hyaluronate, the positive control. The rationale used to characterize the new structures is outlined along with the related biosynthetic pathways envisioned to generate roseoside and Eriojaposide B. These findings provide new molecular insights to deepen the understanding of how V. yedoensis extract, along with the biomarkers aesculin and schaftoside, restores the skin barrier and skin hydration benefits. [ABSTRACT FROM AUTHOR]

Background: Progressive implementation of the milestone competence-based curriculum has created a need for new objective and validated means to assess resident surgical proficiency. A previous systematic review of the literature by our group has highlighted a shortage of tools assessing surgical competence in oncologic procedures in otolaryngology--head and neck surgery. Methods: We developed a procedure-specific assessment tool for neck dissection using a modified Delphi method. The 2-part design was modelled on the previously validated Objective Structured Assessment of Technical Skills checklist. The tool was then validated through a 1-year multicentric prospective study in collaboration with the residents and faculty from our academic centre. Additionally, we developed an online survey to assess the acceptability by residents and staff before and after the validation studies. Results: A total of 29 evaluations were completed throughout the 2016-2017 academic year. Acceptability ranked high for both residents and staff, with a single discrepancy in responses regarding a potential formative as opposed to summative use of the tool. Validation study results showed significantly higher checklist scores among senior residents than junior residents, as well as a significant score progression over time (p < 0.05). Trends in scores on the task-specific tool correlated highly to results obtained on a validated global rating scale (p < 0.05). Conclusion: The first tool assessing surgical competence in oncologic otolaryngology--head and neck surgery has been developed and shows promising validity. Contexte : L'application progressive d'un programme de formation axe sur les competences par jalons a force la mise en place d'une nouvelle facon objective et validee d'evaluer les competences des residents en chirurgie. Une precedente revue systematique de la litterature menee par notre groupe avait mis en lumiere un manque d'outils pour evaluer les competences en chirurgie oncologique de la tete et du cou. Methodes : Nous avons elabore un outil d'evaluation specifique pour la dissection du cou a l'aide d'une methode Delphi modifiee. Le modele en 2 parties s'inspire de la liste de verification validee existante pour l'evaluation objective structuree des habiletes techniques (Objective Structured Assessment of Technical Skills). L'outil a ensuite ete valide dans le cadre d'une etude multicentrique prospective d'une duree de 1 an, en collaboration avec les residents et professeurs de notre centre universitaire. Nous avons aussi prepare un questionnaire en ligne pour en evaluer l'acceptabilite aupres des residents et des professeurs avant et apres les etudes de validation. Resultats : En tout, 29 evaluations ont ete completees au cours de l'annee de formation 2016-2017. L'acceptabilite a recu un score eleve aupres des residents et des professeurs, avec une seule disparite dans les reponses concernant une utilisation potentiellement formative plutdt que sommative de l'outil. Les resultats des etudes de validation ont montre des scores significativement plus eleves pour la liste de verification parmi les residents seniors par rapport aux residents juniors, ainsi qu'une importante progression des scores avec le temps (p < 0,05). Les tendances des scores pour ce qui est de l'outil specifique a la tache ont ete en etroite correlation avec les resultats obtenus sur une echelle d'evaluation globale validee (p < 0,05). Conclusion : Un premier outil d'evaluation des competences en chirurgie oncologique de la tete et du cou a ete cree et sa validite est prometteuse., The future of Canadian otolaryngology--head and neck surgery (OTL-HNS) is shaped by the practices of the hundreds of surgeons throughout the country, who are in turn a product of the [...]

Bacillus cereus is responsible for foodborne outbreaks worldwide. Among the produced toxins, cereulide induces nausea and vomiting after 30 min to 6 h following the consumption of contaminated foods. Cereulide, a cyclodepsipeptide, is an ionophore selective to K+ in solution. In electrospray, the selectivity is reduced as [M + Li]+; [M + Na]+ and [M + NH4]+ can also be detected without adding corresponding salts. Two forms are possible for alkali‐cationized ions: charge‐solvated (CS) that exclusively dissociates by releasing a bare alkali ion and protonated salt (PS), yielding alkali product ions by covalent bond cleavages (CBC) promoted by mobile proton. Based on a modified peptide cleavage nomenclature, the PS product ion series (b, a, [b + H2O] and [b + CnH2nO] [n = 4, 5]) are produced by Na+/Li+/K+‐cationized cereulide species that specifically open at ester linkages followed by proton mobilization promoting competitive ester CBC as evidenced under resonant collision activation. What is more, unlike the sodiated or lithiated cereulide, which regenerates little or no alkali cation, the potassiated forms lead to an abundant K+ regeneration. This occurs by splitting of (i) the potassiated CS forms with an appearance threshold close to that of the PS first fragment ion generation and (ii) eight to four potassiated residue product ions from the PS forms. Since from Na+/Li+‐cationized cereulide, (i) the negligible Na+/Li+ regeneration results in a higher sensibility than that of potassiated forms that abundantly releasing K+, and (ii) a better sequence recovering, the use of Na+ (or Li+) should be more pertinent to sequence isocereulides and other cyclodepsipeptides. [ABSTRACT FROM AUTHOR]

The combined use of hydrogen/deuterium exchange (HDX) and mass spectrometry (MS), referred to as HDX‐MS, is a powerful tool for exploring molecular edifices and has been used for over 60 years. Initially for structural and mechanistic investigation of low‐molecular weight organic compounds, then to study protein structure and dynamics, then, the craze to study small molecules by HDX‐MS accelerated and has not stopped yet. The purpose of this review is to present its different facets with particular emphasis on recent developments and applications. Reversible H/D exchanges of mobilizable protons as well as stable exchanges of non‐labile hydrogen are considered whether they are taking place in solution or in the gas phase, or enzymatically in a biological media. Some fundamental principles are restated, especially for gas‐phase processes, and an overview of recent applications, ranging from identification to quantification through the study of metabolic pathways, is given. [ABSTRACT FROM AUTHOR]

Recently, high-resolution mass spectrometry has been largely employed for compound identification, thanks to accurate mass measurements. As additional information, relative isotope abundance (RIA) is often needed to reduce the number of candidates prior to tandem [MS.sup.n]. Here, we report on the evaluation of the LTQ-Orbitrap, in terms of accurate mass and RIA measurements for building further metabolomica spectral databases. Accurate mass measurements were achieved in the ppm range, using external calibration within 24 h, and remained at 10.1021/ac100271J