The calcium transporter ANNEXIN1 mediates cold-induced calcium signaling and freezing tolerance in plants.

The transient elevation of cytosolic free calcium concentration ([Ca2+ ]cyt ) induced by cold stress is a well-established phenomenon; however, the underlying mechanism remains elusive. Here, we report that the Ca2+ -permeable transporter ANNEXIN1 (AtANN1) mediates cold-triggered Ca2+ influx and freezing tolerance in Arabidopsis thaliana. The loss of function of AtANN1 substantially impaired freezing tolerance, reducing the cold-induced [Ca2+ ]cyt increase and upregulation of the cold-responsive CBF and COR genes. Further analysis showed that the OST1/SnRK2.6 kinase interacted with and phosphorylated AtANN1, which consequently enhanced its Ca2+ transport activity, thereby potentiating Ca2+ signaling. Consistent with these results and freezing sensitivity of ost1 mutants, the cold-induced [Ca2+ ]cyt elevation in the ost1-3 mutant was reduced. Genetic analysis indicated that AtANN1 acts downstream of OST1 in responses to cold stress. Our data thus uncover a cascade linking OST1-AtANN1 to cold-induced Ca2+ signal generation, which activates the cold response and consequently enhances freezing tolerance in Arabidopsis.

Unraveling the Ultrafast Photochemical Dynamics of Nitrobenzene in Aqueous Solution.

Nitroaromatic compounds are major constituents of the brown carbon aerosol particles in the troposphere that absorb near-ultraviolet (UV) and visible solar radiation and have a profound effect on the Earth's climate. The primary sources of brown carbon include biomass burning, forest fires, and residential burning of biofuels, and an important secondary source is photochemistry in aqueous cloud and fog droplets. Nitrobenzene is the smallest nitroaromatic molecule and a model for the photochemical behavior of larger nitroaromatic compounds. Despite the obvious importance of its droplet photochemistry to the atmospheric environment, there have not been any detailed studies of the ultrafast photochemical dynamics of nitrobenzene in aqueous solution. Here, we combine femtosecond transient absorption spectroscopy, time-resolved infrared spectroscopy, and quantum chemistry calculations to investigate the primary steps following the near-UV (λ ≥ 340 nm) photoexcitation of aqueous nitrobenzene. To understand the role of the surrounding water molecules in the photochemical dynamics of nitrobenzene, we compare the results of these investigations with analogous measurements in solutions of methanol, acetonitrile, and cyclohexane. We find that vibrational energy transfer to the aqueous environment quenches internal excitation, and therefore, unlike the gas phase, we do not observe any evidence for formation of photoproducts on timescales up to 500 ns. We also find that hydrogen bonding between nitrobenzene and surrounding water molecules slows the S1/S0 internal conversion process.

Molecularly imprinted nanogels as synthetic recognition materials for the ultrasensitive detection of periodontal disease biomarkers.

Periodontal disease affects supporting dental structures and ranks among one of the top most expensive conditions to treat in the world. Moreover, in recent years, the disease has also been linked to cardiovascular and Alzheimer's diseases. At present, there is a serious lack of accurate diagnostic tools to identify people at severe risk of periodontal disease progression. Porphyromonas gingivalis is often considered one of the most contributing factors towards disease progression. It produces the Arg- and Lys-specific proteases Rgp and Kgp, respectively. Within this work, a short epitope sequence of these proteases is immobilised onto a magnetic nanoparticle platform. These are then used as a template to produce high-affinity, selective molecularly imprinted nanogels, using the common monomers N-tert-butylacrylamide (TBAM), N-isopropyl acrylamide (NIPAM), and N-(3-aminopropyl) methacrylamide hydrochloride (APMA). N,N-Methylene bis(acrylamide) (BIS) was used as a crosslinking monomer to form the interconnected polymeric network. The produced nanogels were immobilised onto a planar gold surface and characterised using the optical technique of surface plasmon resonance. They showed high selectivity and affinity towards their template, with affinity constants of 79.4 and 89.7 nM for the Rgp and Kgp epitope nanogels, respectively. From their calibration curves, the theoretical limit of detection was determined to be 1.27 nM for the Rgp nanogels and 2.00 nM for the Kgp nanogels. Furthermore, they also showed excellent selectivity against bacterial culture supernatants E8 (Rgp knockout), K1A (Kgp knockout), and W50-d (wild-type) strains in complex medium of brain heart infusion (BHI).

O-HEALTH-EDU: A viewpoint into the current state of Oral Health Professional education in Europe: Part 1: Programme-level data.

INTRODUCTION: Current legislation leaves Oral Health Professional (OHP) education open to wide interpretation and may result in significant variation in educational practice and resultant professional attributes across Europe. Data regarding the current state of OHP education across Europe is limited. The aim of Part 1 of this series is to provide programme-level data for Primary Dental Degree Programmes, Dental Hygiene and Postgraduate Education. METHODS: A 91-item questionnaire was developed following the Delphi method. The questionnaire and the Articulate glossary of OHP education terms were developed concurrently to facilitate a common understanding of language. Piloting was performed in multiple stages and included institutions internal and external to the research group. The questionnaire was uploaded online and converted to a data hub, allowing dental schools to control their own data and update the data provided whenever they wish. All ADEE member schools (n = 144) were invited to provide data. Forty questions relating to school details, Primary Dental Degree Programmes, Dental Hygiene and Postgraduate Education were included in this part of the series. RESULTS: Seventy-one institutions from 25 European countries provided data between June 2021 and April 2023, which represents a response rate of 49.3% of ADEE members. Programme-level data for Primary Dental Degree Programmes, Dental Hygiene and Postgraduate Education is presented including programme length, funding, languages and fees, student numbers and demographics, student admission and selection processes and permission to practice after graduation. CONCLUSION: This series of papers, as far as the authors are aware, are the first attempts to build a comprehensive picture of the current state of OHP education in Europe. A comprehensive view of the state of OHP education in Europe is not yet available but the O-Health-Edu data hub provides a means for all education providers in Europe to contribute data to reach this goal. It is anticipated that the data hub will be updated and built upon over time to continually establish a clearer picture of the state of OHP education in Europe.

O-Health-Edu: A viewpoint into the current state of oral health professional education in Europe: Part 2: Curriculum structure, facilities, staffing and quality assurance.

INTRODUCTION: Oral health professional (OHP) education is likely to vary across Europe in accordance with an EU directive that is open to broad interpretation. It is not clear how OHP curricula are structured or delivered across Europe. The objectives of Part 2 of this paper series are: (i) to provide an overview of common practices in curriculum structure, the availability of facilities, staffing (faculty) and quality assurance processes and (ii) to consider how the existing programme structures align to stakeholder guidance documents. METHODS: A total of 27 questions from a 91-item questionnaire were used for this manuscript. The questionnaire was developed following the Delphi method to establish consensus from a group of experts. Members of the research team and colleagues from other countries in Europe completed a multi-step piloting process. An online data hub was created to allow the respondents to be data controllers and respond to the questionnaire. ADEE member schools (n = 144) were invited to provide data. RESULTS: Totally, 71 institutions from 25 European countries provided data between June 2021 and April 2023, which represents a response rate of 49.3% of ADEE members. Data on curriculum approaches, teaching methods, integration of topics of interest, clinical education, staff-student ratios, access to facilities and new technologies, teaching staff (faculty) and quality assurance processes are presented for Primary Dental Degree Programmes. CONCLUSION: To the best of our knowledge, this series of papers are the first attempts to provide a comprehensive overview of OHP education in Europe. Results showed that the majority of European dental programmes are engaged in providing innovative and scientifically grounded education in order to develop quality future OHPs. Nevertheless, significant variability in the delivery of clinical education across the European OHP schools was notable in this dataset. A comprehensive view of the state of OHP education in Europe is not yet available but the O-Health-Edu data hub provides a means for all education providers in Europe to contribute data to reach this goal. It is anticipated that the data hub will be updated and built upon over time to continually establish a clearer picture of the state of OHP education in Europe.

Cyclic nucleotide-gated ion channel 6 is involved in extracellular ATP signaling and plant immunity.

Extracellular ATP (eATP) is known to act as a danger signal in both plants and animals. In plants, eATP is recognized by the plasma membrane (PM)-localized receptor P2K1 (LecRK-I.9). Among the first measurable responses to eATP addition is a rapid rise in cytoplasmic free calcium levels ([Ca2+ ]cyt ), which requires P2K1. However, the specific transporter/channel proteins that mediate this rise in [Ca2+ ]cyt are unknown. Through a forward genetic screen, we identified an Arabidopsis ethylmethanesulfonate (EMS) mutant impaired in the [Ca2+ ]cyt response to eATP. Positional cloning revealed that the mutation resided in the cngc6 gene, which encodes cyclic nucleotide-gated ion channel 6 (CNGC6). Mutation of the CNGC6 gene led to a notable decrease in the PM inward Ca2+ current in response to eATP. eATP-induced mitogen-activated protein kinase activation and gene expression were also significantly lower in cngc6 mutant plants. In addition, cngc6 mutant plants were also more susceptible to the bacterial pathogen Pseudomonas syringae. Taken together, our results indicate that CNGC6 plays a crucial role in mediating eATP-induced [Ca2+ ]cyt signaling, as well as plant immunity.

Zero Threshold for Water Adsorption on MAPbBr3.

Hybrid organic-inorganic perovskites (HOIPs) have shown great promise in a wide range of optoelectronic applications. However, this performance is inhibited by the sensitivity of HOIPs to various environmental factors, particularly high levels of relative humidity. This study uses X-ray photoelectron spectroscopy (XPS) to determine that there is essentially no threshold to water adsorption on the in situ cleaved MAPbBr3 (001) single crystal surface. Using scanning tunneling microscopy (STM), it shows that the initial surface restructuring upon exposure to water vapor occurs in isolated regions, which grow in area with increasing exposure, providing insight into the initial degradation mechanism of HOIPs. The electronic structure evolution of the surface was also monitored via ultraviolet photoemission spectroscopy (UPS), evidencing an increased bandgap state density following water vapor exposure, which is attributed to surface defect formation due to lattice swelling. This study will help to inform the surface engineering and designs of future perovskite-based optoelectronic devices.

Onset of Rotational Decoupling for a Molecular Ion Solvated in Helium: From Tags to Rings and Shells.

Little is known about how rotating molecular ions interact with multiple ^{4}He atoms and how this relates to microscopic superfluidity. Here, we use infrared spectroscopy to investigate ^{4}He_{N}⋯H_{3}O^{+} complexes and find that H_{3}O^{+} undergoes dramatic changes in rotational behavior as ^{4}He atoms are added. We present evidence of clear rotational decoupling of the ion core from the surrounding helium for N>3, with sudden changes in rotational constants at N=6 and 12. In sharp contrast to studies on small neutral molecules microsolvated in helium, accompanying path integral simulations show that an incipient superfluid effect is not needed to account for these findings.

Traumatic Brain Injury History Among Individuals Using Mental Health and Addictions Services: A Scoping Review.

OBJECTIVE: Traumatic brain injury (TBI) has been increasingly linked in population research to psychiatric problems as well as substance use and related harms, suggesting that individuals with TBI may also present more frequently to mental health and addictions (MHA) services. Little is known, however, about TBI history among MHA service users. The objectives of this review were to understand (i) the prevalence of TBI history among MHA service users; (ii) how TBI history is identified in MHA service settings; and (iii) predictors or outcomes of TBI that have been reported in MHA service users. METHODS: A scoping review was conducted in accordance with PRISMA Scoping Review Extension guidelines. A search for relevant literature was conducted in MEDLINE, PsycINFO, SPORTDiscus, CINAHL, and Embase as well as various gray literature sources. RESULTS: Twenty-eight relevant studies were identified. TBI was defined and operationalized heterogeneously between studies, and TBI history prevalence rates ranged considerably among the study samples. The included studies used varied methods to identify TBI history in MHA settings, such as clinical chart audits, single-item questions, or structured questionnaires (eg, Brain Injury Screening Questionnaire or Ohio State University TBI Identification Method). TBI history was most consistently associated with indicators of more severe substance use problems and mental health symptoms as well as increased aggression or risk to others. Studies reported less consistent findings regarding the relationship of TBI to physical health, cognitive impairment, functioning, risk to self, and type of psychiatric diagnosis. CONCLUSION: Screening for TBI history in MHA settings may contribute important information for risk assessment and care planning. However, to be clinically useful, assessment of TBI history will require consistent operationalization of TBI as well as use of validated screening methods.

Validation of the Transition Readiness Assessment Questionnaire (TRAQ) 5.0 for use among youth in mental health services.

BACKGROUND: Among youth with psychiatric disorders, the transition from child to adult mental health services is a period of vulnerability to discontinuous care and service disengagement. Regular assessment of transition readiness has been identified as a core component of transition planning, contributing to successful care transitions. The Transition Readiness Assessment Questionnaire (TRAQ) 5.0 is a 20-item questionnaire that measures transition readiness in youth preparing to transition to adult care. Although the TRAQ has been validated and used across many health settings, it has not been validated in youth with primarily mental health concerns. The objective of this study was to validate the TRAQ for use among youth accessing mental health services. METHODS: This study used the Longitudinal Youth in Transition Study baseline cohort, which consists of 237 clinically referred youth (aged 16-18 years) receiving outpatient mental health treatment. Psychometric evaluation of the TRAQ 5.0 included confirmatory factor analysis (CFA), assessment of internal consistency, testing convergent validity using the Dimensions of Emerging Adulthood (IDEAS) and Difficulty in Emotional Regulation (DERS) scales, criterion validity using a question on whether the participant had talked about transition with their clinician and known-group testing based on age. RESULTS: The CFA indicated adequate fit of the five-factor TRAQ structure. The overall scale (=.86) and three of the subscales demonstrated adequate internal consistency. As hypothesized, overall TRAQ scores were higher for youth who had discussed transition and those aged 18. Small correlations were found between the overall TRAQ score and measures of developmental maturity (IDEAS) and emotional awareness (DERS); however, certain subscales did not demonstrate correlation with these constructs. CONCLUSIONS: The TRAQ 5.0 appears to be valid tool to assess the transition readiness of youth in outpatient mental health services. Additional work needs determine whether findings are similar among specific mental health conditions, including substance use disorders and psychotic disorders.

ARTICULATE: A European glossary of terms used in oral health professional education.

INTRODUCTION: The Erasmus+O-Health-EDU project aims to gain a comprehensive view of oral health professional (OHP) education in Europe, through the development of web-based surveys and online toolkits. A glossary to facilitate a common language through which academic teams could cooperate and communicate more accurately was identified as a key need within the project. The aim of ARTICULATE was thus to create a shared language, with a European focus, for terms and concepts used in the field of OHP education. METHODS: The methodology was developed from those published for construction of other glossaries with a circular and iterative process: the creation of content and definitions by a group of experts in OHP education, the testing of "fitness for purpose" of the content, and stakeholder consultation. All creation steps were followed by refinements based on testing results and stakeholder comments. The final glossary was then launched as an online resource including a built-in mechanism for user feedback. RESULTS: The scope and structure of the glossary were mapped out at a workshop with 12 dental education experts from 7 European countries. A total of 328 terms were identified, of which 171 were finally included in ARTICULATE. After piloting with a close group of other colleagues, the glossary was opened for external input. Thirty European Deans or Heads of Education assessed the definition of each term as "clear" or "not clear." A total of 86 definitions were described as "clear" by all individuals. Terms deemed unclear by at least one individual were revisited and changes made to 37 of the definitions. In conjunction with the launch of the glossary, a range of stakeholder organisations were informed and asked to participate in an open global consultation by providing feedback online. Since its launch in June 2021, the ARTICULATE website (https://o-health-edu.org/articulate) has had an average of 500 visits/month. To promote community ownership, forms embedded on the ARTICULATE webpage allow users to give feedback and suggest new terms. A standing taskforce will meet regularly to consider amendments and make changes to ensure that the glossary remains a relevant and up-to-date resource over time. CONCLUSION: ARTICULATE is a unique, evolving, online glossary of terms relating to OHP education, created as a resource for all interested OHP educators. The glossary is a key output of the O-Health-Edu project, which relies on a comprehensive vision of OHP education to address the future oral health needs of the European population.

O-Health-Edu: A vision for oral health professional education in Europe.

This consensus paper reports on the process of developing a renewed vision for Oral Health Professional (OHP) education across Europe, and forms part of a larger EU-funded collaborative Erasmus+ project, "O-Health-Edu." The vision aligns with the World Health Organisation milestones (2016) and resolutions (2021), and EU4Health programme (2020) objectives - and projects 20 years into the future, to 2040. This longitudinal vision takes a multi-stakeholder perspective to deliver OHP education that acts in the best interests of both students and patients, and sits within the context of a wider strategy for general health. Included, it is an infographic to help communicate the vision to various stakeholders of OHP education.

Streptococcus gordonii Poised for Glycan Feeding through a MUC5B-Discriminating, Lipoteichoic Acid-Mediated Outside-In Signaling Circuit.

Many oral bacteria employ cell wall-anchored adhesins to bind to the salivary films coating the teeth and mucosal surfaces. Surface binding prevents clearance and facilitates catabolism of salivary film glycoproteins. We asked whether Streptococcus gordonii adhesin expression changes in response to surface salivary cues using a eukaryote-like, outside-in recognition and signaling circuit. To determine whether the cues were discriminated, S. gordonii was tested during cell adhesion and biofilm formation on a MUC5B-rich or lower-molecular-mass salivary fraction or an uncoated abiotic surface. Cells were recovered and analyzed for differences in gene expression and proteins in cell wall fractions. In salivary-free conditions, planktonic S. gordonii presented three prominent cell wall LPXTG-motif proteins, SGO_1487, SGO_0890, and MbpA (mucin-binding protein A; SGO_0707). During biofilm formation on MUC5B-coated surfaces, MbpA, a MUC5B-binding protein, and key genes in the tagatose and quorum-sensing pathways were strongly promoted. The response to MUC5B required the two-component system (TCS), streptococcal regulator of adhesins sensor and regulator (SraSR, SGO_1180/81), lipoteichoic acid (LTA), and the homologous paired adhesins, SspA and SspB (SspAB). LTA appears to link the outside signal (MUC5B) to intramembrane SraSR. Tagatose pathway gene expression may poise cells to metabolize MUC5B glycans and, with a quorum-sensing gene (luxS), may direct formation of a consortium to facilitate glycan cross-feeding by S. gordonii. We now show that a Gram-positive bacterium discriminates specific surface environmental cues using an outside-in signaling mechanism to apparently optimize colonization of saliva-coated surfaces. IMPORTANCE All organisms throughout the tree of life sense and respond to their surface environments. To discriminate among mucosal surface environmental cues, we report that Streptococcus gordonii recognizes a high-molecular-weight mucin glycoprotein, MUC5B, using the paired adhesins SspAB and lipoteichoic acid; the latter bridges the outside signal to an intramembrane two-component system to transcriptionally regulate a MUC5B-specific adhesin and genes that may facilitate glycan catabolism.

Depletion plays a pivotal role in self-incompatibility, revealing a link between cellular energy status, cytosolic acidification and actin remodelling in pollen tubes.

Self-incompatibility (SI) involves specific interactions during pollination to reject incompatible ('self') pollen, preventing inbreeding in angiosperms. A key event observed in pollen undergoing the Papaver rhoeas SI response is the formation of punctate F-actin foci. Pollen tube growth is heavily energy-dependent, yet ATP levels in pollen tubes have not been directly measured during SI. Here we used transgenic Arabidopsis lines expressing the Papaver pollen S-determinant to investigate a possible link between ATP levels, cytosolic pH ([pH]cyt ) and alterations to the actin cytoskeleton. We identify for the first time that SI triggers a rapid and significant ATP depletion in pollen tubes. Artificial depletion of ATP triggered cytosolic acidification and formation of actin aggregates. We also identify in vivo, evidence for a threshold [pH]cyt of 5.8 for actin foci formation. Imaging revealed that SI stimulates acidic cytosolic patches adjacent to the plasma membrane. In conclusion, this study provides evidence that ATP depletion plays a pivotal role in SI upstream of programmed cell death and reveals a link between the cellular energy status, cytosolic acidification and alterations to the actin cytoskeleton in regulating Papaver SI in pollen tubes.

Arabidopsis thaliana CYCLIC NUCLEOTIDE-GATED CHANNEL2 mediates extracellular ATP signal transduction in root epidermis.

Damage can be signalled by extracellular ATP (eATP) using plasma membrane (PM) receptors to effect cytosolic free calcium ion ([Ca2+ ]cyt ) increase as a second messenger. The downstream PM Ca2+ channels remain enigmatic. Here, the Arabidopsis thaliana Ca2+ channel subunit CYCLIC NUCLEOTIDE-GATED CHANNEL2 (CNGC2) was identified as a critical component linking eATP receptors to downstream [Ca2+ ]cyt signalling in roots. Extracellular ATP-induced changes in single epidermal cell PM voltage and conductance were measured electrophysiologically, changes in root [Ca2+ ]cyt were measured with aequorin, and root transcriptional changes were determined by quantitative real-time PCR. Two cngc2 loss-of-function mutants were used: cngc2-3 and defence not death1 (which expresses cytosolic aequorin). Extracellular ATP-induced transient depolarization of Arabidopsis root elongation zone epidermal PM voltage was Ca2+ dependent, requiring CNGC2 but not CNGC4 (its channel co-subunit in immunity signalling). Activation of PM Ca2+ influx currents also required CNGC2. The eATP-induced [Ca2+ ]cyt increase and transcriptional response in cngc2 roots were significantly impaired. CYCLIC NUCLEOTIDE-GATED CHANNEL2 is required for eATP-induced epidermal Ca2+ influx, causing depolarization leading to [Ca2+ ]cyt increase and damage-related transcriptional response.

Dimerization dynamics of carboxylic acids in helium nanodroplets.

The dimerization of molecules in helium nanodroplets is known to preferentially yield structures of higher energy than the global energy minimum structure for a number of quite different monomers. Here, we explore dimerization in this environment using an atomistic model within statistically converged molecular dynamics (MD) trajectories, treating the solvent implicitly through the use of a thermostat, or more explicitly by embedding one monomer in a He100 cluster. The focus is on the two simplest carboxylic acids, formic and acetic, both of which have been studied experimentally. While the global minimum structure, which comprises two CO⋯HO hydrogen bonds, is predicted to be the most abundant dimer in the absence of the helium solvent, this is no longer the case once helium atoms are included. The simulations confirm the importance of kinetic trapping effects and also shed light on the occurrence of specific dynamical effects, leading to the occasional formation of high-energy structures away from minima, such as saddle configurations. Theoretically predicted infrared spectra, based on the MD statistics, are in good agreement with the experimental spectra.

The Longitudinal Youth in Transition Study (LYiTS) Cohort Profile: Exploration by Hospital- Versus Community-Based Mental Health Services.

OBJECTIVES: Youth face numerous challenges in receiving coordinated and continuous mental health services, particularly as they reach the age of transition from child and adolescent mental health services (CAMHS) to adult mental health services (AMHS). The Longitudinal Youth in Transition Study (LYiTS) follows youth prospectively as they cross this transition boundary to better understand their transition pathways and resulting symptoms and health service use outcomes. The current paper presents the baseline profile description for the LYiTS cohort and additionally examines differences in symptoms and functioning and health service utilization between youth receiving services at hospital- versus community-based CAMHS. METHODS: A cross-sectional design was used. A sample of 237 16-18-year-old youth recruited from outpatient CAMHS at two hospitals and two community sites completed self-report measures at their first of four annual assessments. A latent profile analysis was conducted to identify symptomology profiles, and youth were compared on symptoms and health service use between hospital- and community-based sites. RESULTS: Four distinct symptomology profiles were identified (subclinical, moderate internalizing, moderate externalizing, and high symptomology). Symptom profiles and functioning levels reported by youth were no different across both types of organization, although there were differences detected in health service utilization, such as type of provider seen and use of medications. CONCLUSIONS: These findings suggest that there is little difference in symptomology between youth accessing hospital versus community-based CAMHS. With growing interest in understanding the effectiveness and cost-effectiveness of different models of mental health care, these findings provide a new understanding of the clinical and service use profiles of transition-aged youth that will be explored further as this cohort is followed across the CAMHS to AMHS transition boundary.

Prioritizing core components of successful transitions from child to adult mental health care: a national Delphi survey with youth, caregivers, and health professionals.

Youth accessing mental health care often experience a disruption in care as they attempt to transition between child and adolescent mental health services (CAMHS) and adult mental health services (AMHS). Few studies have evaluated interventions seeking to improve the experience and outcomes of CAMHS-AMHS transitions, in part due to lack of consensus on what constitutes best practices in intervention success. As such, the aim of this study was to engage patients, caregivers, and clinicians to prioritize core components of successful CAMHS-AMHS transitions which can be used in the design or evaluation of transition interventions. As such, a Delphi study was conducted to determine core components of successful CAMHS-AMHS transitions. Guided by the principles of patient-oriented research, three balanced expert panels consisting of youth, caregivers, and clinicians ranked and provided feedback on the importance and feasibility of core components of CAMHS-AMHS transitions. Components endorsed as feasible or important with ≥ 70% agreement from any panel moved to the next round. As a result, a list of 26 core components of CAMHS-AMHS transitions has been refined which can be used in the design, implementation, or evaluation of interventions intended to improve transition experiences and outcomes for youth in mental health care. Youth and families were engaged in an expert advisory role throughout the research process, contributing their important perspectives to the design and implementation of this study, as well as interpretation of the findings.

Effects of stabilized hypochlorous acid on oral biofilm bacteria.

BACKGROUND: Caries and periodontitis are amongst the most prevalent diseases worldwide, leading to pain and loss of oral function for those affected. Prevention relies heavily on mechanical removal of dental plaque biofilms but for populations where this is not achievable, alternative plaque control methods are required. With concerns over undesirable side-effects and potential bacterial resistance due to the use of chlorhexidine gluconate (CHX), new antimicrobial substances for oral use are greatly needed. Here we have investigated the antimicrobial effect of hypochlorous acid (HOCl), stabilized with acetic acid (HAc), on oral biofilms and compared it to that of CHX. Possible adverse effects of stabilized HOCl on hydroxyapatite surfaces were also examined. METHODS: Single- and mixed-species biofilms of six common oral bacteria (Streptococcus mutans, Streptococcus gordonii, Actinomyces odontolyticus, Veillonella parvula, Parvimonas micra and Porphyromonas gingivalis) within a flow-cell model were exposed to HOCl stabilized with 0.14% or 2% HAc, pH 4.6, as well as HOCl or HAc alone. Biofilm viability was assessed in situ using confocal laser scanning microscopy following LIVE/DEAD® BacLight™ staining. In-situ quartz crystal microbalance with dissipation (QCM-D) was used to study erosion of hydroxyapatite (HA) surfaces by stabilized HOCl. RESULTS: Low concentrations of HOCl (5 ppm), stabilized with 0.14% or 2% HAc, significantly reduced viability in multi-species biofilms representing supra- and sub-gingival oral communities, after 5 min, without causing erosion of HA surfaces. No equivalent antimicrobial effect was seen for CHX. Gram-positive and Gram-negative bacteria showed no significant differential suceptibility to stabilized HOCl. CONCLUSIONS: At low concentrations and with exposure times which could be achieved through oral rinsing, HOCl stabilized with HAc had a robust antimicrobial activity on oral biofilms, without causing erosion of HA surfaces or affecting viability of oral keratinocytes. This substance thus appears to offer potential for prevention and/or treatment of oral biofilm-mediated diseases.

Acid tolerance in early colonizers of oral biofilms.

BACKGROUND: In caries, low pH drives selection and enrichment of acidogenic and aciduric bacteria in oral biofilms, and development of acid tolerance in early colonizers is thought to play a key role in this shift. Since previous studies have focussed on planktonic cells, the effect of biofilm growth as well as the role of a salivary pellicle on this process is largely unknown. We explored acid tolerance and acid tolerance response (ATR) induction in biofilm cells of both clinical and laboratory strains of three oral streptococcal species (Streptococcus gordonii, Streptococcus oralis and Streptococcus mutans) as well as two oral species of Actinomyces (A. naeslundii and A. odontolyticus) and examined the role of salivary proteins in acid tolerance development. METHODS: Biofilms were formed on surfaces in Ibidi® mini flow cells with or without a coating of salivary proteins and acid tolerance assessed by exposing them to a challenge known to kill non-acid tolerant cells (pH 3.5 for 30 min) followed by staining with LIVE/DEAD BacLight and confocal scanning laser microscopy. The ability to induce an ATR was assessed by exposing the biofilms to an adaptation pH (pH 5.5) for 2 hours prior to the low pH challenge. RESULTS: Biofilm formation significantly increased acid tolerance in all the clinical streptococcal strains (P < 0.05) whereas the laboratory strains varied in their response. In biofilms, S. oralis was much more acid tolerant than S. gordonii or S. mutans. A. naeslundii showed a significant increase in acid tolerance in biofilms compared to planktonic cells (P < 0.001) which was not seen for A. odontolyticus. All strains except S. oralis induced an ATR after pre-exposure to pH 5.5 (P < 0.05). The presence of a salivary pellicle enhanced both acid tolerance development and ATR induction in S. gordonii biofilms (P < 0.05) but did not affect the other bacteria to the same extent. CONCLUSIONS: These findings suggest that factors such as surface contact, the presence of a salivary pellicle and sensing of environmental pH can contribute to the development of high levels of acid tolerance amongst early colonizers in oral biofilms which may be important in the initiation of caries.