In Vitro and Ex Vivo Models of Microbial Keratitis: Present and Future.

Microbial keratitis (MK) is an infection of the cornea, caused by bacteria, fungi, parasites, or viruses. MK leads to significant morbidity, being the fifth leading cause of blindness worldwide. There is an urgent requirement to better understand pathogenesis in order to develop novel diagnostic and therapeutic approaches to improve patient outcomes. Many in vitro, ex vivo and in vivo MK models have been developed and implemented to meet this aim. Here, we present current in vitro and ex vivo MK model systems, examining their varied design, outputs, reporting standards, and strengths and limitations. Major limitations include their relative simplicity and the perceived inability to study the immune response in these MK models, an aspect widely accepted to play a significant role in MK pathogenesis. Consequently, there remains a dependence on in vivo models to study this aspect of MK. However, looking to the future, we draw from the broader field of corneal disease modelling, which utilises, for example, three-dimensional co-culture models and dynamic environments observed in bioreactors and organ-on-a-chip scenarios. These remain unexplored in MK research, but incorporation of these approaches will offer further advances in the field of MK corneal modelling, in particular with the focus of incorporation of immune components which we anticipate will better recapitulate pathogenesis and yield novel findings, therefore contributing to the enhancement of MK outcomes.

Speaking the Same Language - The Development of a Glossary of Terms for Social Prescribing in Wales.

Introduction: Social prescribing can facilitate the integration of health, social care and community support but has a diverse and confusing terminology that impairs cross-sectoral communication and creates barriers to engagement. Methods: To address this issue a mixed-methods approach that incorporated a scoping review, a group concept mapping study and consultation was employed to identify and classify the terminology associated with social prescribing. The findings were then used to inform the development of a glossary of terms for social prescribing. Results: Many terms are used interchangeably to describe the same specific aspects of social prescribing. Much of the terminology originates from the health and social care literature of England. Discussion: The terminology used in the academic literature may not accurately reflect the terminology used by the social prescribing workforce. The innovative and interactive glossary of terms identifies the terminology associated with social prescribing and provides additional contextual information. The process of developing the dual language glossary presented several considerations and challenges. Conclusion: The glossary of terms will facilitate cross-sector communication and reduce barriers to engagement with social prescribing. It takes an important first step to help clarify and standardise the language associated with social prescribing, for professionals and members of the public alike.

Micro-Computed Tomography Analysis of Resin and Calcium Silicate Based Sealers Removal in Mandibular Molars Curved Canals.

Objective: The removal of the root canal sealer is an important factor in nonsurgical retreatment. The aim of this study was to compare the removal of AH Plus, Well Root ST, and AH Plus Bioceramic Sealer using Protaper Universal retreatment files. Methods: The curved mesio-buccal canals of extracted mandibular molars were prepared with the Protaper Gold file system (up to F2). Specimens were randomly divided into 3 groups and filled with the single cone technique using AH Plus, Well-Root ST, and AH Plus Bioceramic Sealer, respectively. After two weeks, the root canal filling of all specimens was removed using Protaper Universal retreatment files. All specimens were scanned using micro-CT. The remaining volume of the root canal filling was recorded in total and the coronal, middle, and apical third of each specimen. Results: Well-Root ST and AH Plus Bioceramic Sealer groups had a higher percentage of total remaining filling material than the AH Plus group (P<0.05). Conclusion: This study has shown that the volume of remaining root canal filling was significantly higher in the samples filled with calcium silicate-based sealers.

Patients' and Parents' Concerns over Orthodontic Treatment during the COVID - 19 Pandemic.

Objective: We aimed to assess the impact of the COVID-19 pandemic on the concern of adolescents in orthodontic treatment, and to determine whether personality traits and parental perception were predictors of adolescent patients' concerns. Participants and methods: The sample consisted of 229 adolescent patients (57.2% female) and 223 parents (65.1% female). Questionnaires included items about the importance of infection control and concern about treatment duration and results. Their latent structure was determined using exploratory factor analysis. The Big Five Inventory was used for assessing personality traits. Predictors of patients' and parental orthodontic concern and awareness of the importance of infection control measures were tested by the hierarchical multiple regression analysis. Results: Two factors were revealed for the patient questionnaire, Treatment concern (TC) and Awareness of the importance of measures (AM), and four factors for the parent questionnaire, Parents' treatment concern (PTC), Parents' awareness of the importance of measures (PAM), Parents' concern about the pandemic (PCP) and Parents' concern about their child with regards to the pandemic (PCC). Adolescents' personality traits were not predictors of either TC or AM. PTC was a predictor of TC (p<0.001), accounting for 28% of the variance. PAM and the patient's following of the news were predictors of AM (p≤0.022), accounting for 24% and 2% of the variance, respectively. Conclusion: Parental concern and awareness of measures had an important role in attitudes of adolescent orthodontic patients during the COVID-19 pandemic, while personality traits did not. The clinician should put additional emphasis on communication with the parent.

Thickness Variations of Thermoformed and 3D-Printed Clear Aligners.

Objective: To assess thickness variations of thermoformed and 3D-printed clear aligners. Materials and Methods: Six different thermoplastic materials with different initial thicknesses were used for aligner thermoforming using Biostar® device (Biostar®, SCHEU-DENTAL GmbH, Iserlohn, Germany). Also, two different dental resins were used to create the printed aligners in three digitally designed thicknesses using IZZI Direct printer (3Dtech, Zagreb, Croatia). The aligners were measured using an electronic micrometer (ELECTRONIC UNIVERSAL MICROMETER, Schut Geometrical Metrology, Groningen, The Netherlands, accuracy: 0.001 mm) on a total of 20 points per aligner. Statistical analysis was performed using the JASP program (JASP, University of Amsterdam, Amsterdam, The Netherlands). Results: The difference between the thermoformed and printed groups was statistically significant. Significant differences between different thermoformed materials and between 3D-printed materials were found. The thickness of thermoformed aligners deviated more in the upper jaw, whereas the thickness of printed aligners deviated more in the lower jaw. Both differences were statistically significant. The greatest average deviation from the initial thickness was found in Duran 0.75; Erkodur 0.6; Erkoloc-Pro 1.0; IZZI 0.5; NextDent 0.6 and NextDent A 0.6. NextDent group had the lowest deviations for all teeth of both jaws, except for upper and lower first molar where NextDent A group was more accurate. Conclusions: Thermoformed aligners showed decreased values, while printed ones showed mostly increased values compared to the original material thickness. The highest mean deviation belonged to IZZI group, and the NextDent group had the lowest mean deviation. The thickness of both aligners was thinner at the edges compared to the thickness at cusps and fissures.

Clinical Survival of Reduced-Thickness Monolithic Lithium-Disilicate Crowns: A 3-Year Randomized Controlled Trial.

Objectives: The aim of this randomized controlled trial was to see if the minimally invasive approach (reduced restoration thickness) would result in good clinical success of monolithic ceramic crowns compared to conventional layered all-ceramic crowns, and thus be an alternative to conventional tooth preparation. Materials and methods: The ceramic that was investigated was IPS e.max lithium-disilicate ceramic produced using two different processing methods. A comparison was made between monolithic crowns with reduced thickness and standard layered crowns. Fifty-two patients, who had undergone endodontic treatment on either a premolar or molar, were randomly assigned into two groups. The teeth intended for layered crowns underwent to a 2 mm occlusal reduction with a 1 mm rounded shoulder, whereas the teeth intended for monolithic crowns underwent to a 1 mm reduction in the occlusal area with a 0.6 mm rounded shoulder. The clinical success was evaluated in eight categories using modified United States Public Health Service (USPHS) criteria. The observation period was 36 months, with control appointments every 6 months. Results: There was no significant difference in clinical success between monolithic and conventional layered crowns after 3 years. One monolithic crown fractured while all other crowns were intact and the survival rate was 96%. All layered crowns were intact and the survival rate was 100%. Conclusion: The results of this study indicate that the minimally invasive approach can be a good alternative to conventional tooth preparation. IPS e.max lithium-disilicate ceramic demonstrated an exceptional three-year survival rate independently of the thickness of the material.

Dental Anxiety Among Students of the University of Rijeka, Croatia.

Objectives: Dental anxiety is a common problem and a great challenge for many patients, but also for dentists - the treatment of anxious patients is considered to be one of the most stressful situations for dentists. The aim of this study was to evaluate the prevalence of dental anxiety among the students of the University of Rijeka and to detect possible differences in the level of anxiety among students of different study programs. Participants and methods: This cross-sectional study included 290 students from different faculties of the University of Rijeka (Faculty of Law, Faculty of Humanities and Social Sciences, Faculty of Engineering, Faculty of Medicine, Faculty of Dental Medicine), 73 (25.17%) male and 217 (74.83%) female students. The study was conducted online via The Modified Dental Anxiety Scale (MDAS) in 2020 and sampling was based on voluntary responses. The Student's t-test and ANOVA were used to compare differences in MDAS scores among students. Results: There is a significant difference in dental anxiety levels between students from the Faculty of Humanities and Social Sciences and Faculty of Dental Medicine (MDAS=11.32±4.11, MDAS=8.84±3.03, p=0.01), and also between students from the Faculty of Law and Faculty of Dental Medicine (MDAS=11.47±4.64, MDAS=8.84±3.03, p <0.01). Conclusions: This research showed that non-dental students have a higher level of dental anxiety than dental students. Sufficient knowledge of dental and oral health could potentially overcome dental fear and anxiety. Therefore, there is a need to provide additional dental education throughout the university curriculum.

Periodontal Disease in Patients with Ischemic Stroke - an Exploratory Study.

Objective: The aim of this study was to assess the periodontal disease parameters in patients with ischemic stroke. Materials and methods: The study included 21 patients with ischemic brain stroke and a control group that was matched in number, age, and gender. All participants underwent a standard periodontal examination. The inclusion criterion of this study was the presence of at least 15 teeth. Periodontal epithelial surface area, periodontal inflamed surface area (PISA), and periodontal disease stage were determined. All participants were given a questionnaire to determine oral health-related quality of life (OHQL). Stroke risk factors were assessed. Results: Stroke patients had a significantly higher OHQL score than the control group (20.81 vs. 12.57) and a full-mouth plaque score (FMPS, 27.57 vs. 16.83), while full-mouth bleeding score (FMBS) was significantly higher in the control group than in the hospital group (10.17 vs. 6.42). For PISA, statistically significant negative correlations were found for smoking, cholesterol levels, and LDL levels, while significant positive correlations were found for FMBS, clinical attachment level and probing depth. Conclusion: Although PISA does represent the amount of periodontal tissue that is inflamed, tooth loss due to advanced periodontal disease combined with oral hygiene limitations imposed by the hospital setting and the stroke recovery process remain the most significant obstacles for a more meaningful understanding of the data represented by specific clinical, laboratory and various demographic parameters that characterize the two diseases.

Evaluation of Sella Turcica Variations in Lateral Cephalometric Radiographs and its Association with Malocclusion.

Objectives: Understanding the shape and size of the sella turcica may help predict future orthodontic treatment needs related to skeletal malocclusion. This study aims to assess different morphological types of the sella turcica in lateral cephalometric radiographs and its correlation with malocclusion, as well as the relationship between gender and linear measurements of sella turcica. Materials and Methods: The lateral cephalometric radiographs of 410 volunteers (111 men and 299 women) aged 8 to 30 years were evaluated. The patients were divided into three groups based on their skeletal growth patterns (cl I, II, and III). Then the anatomical shape and linear dimensions of sella turcica were assessed. Measurements were made using Adobe Photoshop Version: 20.0.0 software, and data analysis was performed by IBM SPSS Statistics version 25. Results: The following morphologies were observed: normal (37.8%), oblique anterior wall (9.3%), double contour of the floor (21.5%), sella turcica bridge (8.8%), irregularity (notching) in the posterior part of sella turcica (16.6%), and pyramidal shape of the dorsum sellae (6.1%). No statistically significant relationship was found between sella turcica variations and skeletal malocclusion. The correlation between female sex with the diameter (p=0.027) and depth values (p=0.035) of sella turcica was statistically significant. There was no statistically significant difference (p>0.05) in length based on gender. Conclusion: The most morphological type reported was normal sella turcica (37.8%). Anatomical variations of sella turcica had no association with malocclusion. The most considerable depth and diameter of sella turcica were found in women.

Assessment of Tooth Shade Measurement Precision and Consistency with Digital Photography Calibration System.

Objectives: To ascertain the degree of precision and repeatability inherent in the "capture to edit" digital imaging system, namely the ColorChecker Passport Photo (X-Rite, MI, USA), and to juxtapose its performance against spectrophotometric assessments utilizing the Vita Easyshade® (Vita Zahnfabrik, H Rauter GmbH & Co. KG., Bad Sackingen, Germany) for the same set of teeth. Materials and methods: Eighty participants aged 19-25 were included in the study; all of them were Croatian students at the School of Dental Medicine, University of Zagreb. Color measurements of the maxillary right central incisors were performed in controlled, standardized laboratory conditions. The measurements were performed on calibrated digital photographs by an experienced clinician three times in a row, and L, a, and b of CIELAB color space values were recorded. The same procedure was performed using the Vita Easyshade 5.0 spectrophotometer (Vita Zahnfabrik, Bad Säckingen, Germany) in "Tooth single" mode. Results: The Cronbach's alpha was used as a repeatability measurement, thus revealing high consistency for both methods (α=0.94-1). Correlations were moderate (Pearson r=0.44-0.66 p<0.05). Testing confirmed that digital photography is inaccurate as spectrophotometry (p<0.05). An analysis of errors of means and their standard deviations revealed consistent discrepancies with minor deviations. Conclusion: The "capture to edit" method showed high consistency (Cronbach's α=0.94-0.96), and it exhibits comparability in terms of variability, reliability, and repeatability when compared to spectrophotometric measurement (VitaShade 5, VitaZahnfabrik). Disparities between the methods are evident and anticipated, yet they do not follow a consistently linear pattern. The combination of repeatability and consistency renders the "capture to edit" method a valuable tool for enhanced color mapping, thus facilitating comparisons between digital images.

Which outcomes are key to the pre-intervention assessment profile of a child with developmental coordination disorder? A systematic review and meta-analysis.

BACKGROUND: Purpose of this study was to determine what key aspects of function should be incorporated to make up a pre-intervention assessment profile of a child with Developmental Coordination Disorder (DCD); more specifically, what aspects of functioning are implicated in DCD and what is their relative impact? METHODS: A systematic review and meta-analysis were conducted, for which Pubmed, Web of Science, Scopus and Proquest were searched (last update: April 2023, PROSPERO: CRD42023461619). Case-control studies were included to determine point estimates for performances on field-based tests in different domains of functioning. Risk of bias was assessed, and level of evidence estimated. Random-effect meta-analyses were performed to calculate the pooled standardized mean differences for domains of functioning and subgrouping was done for clinically relevant subdomains. Heterogeneity was determined with I2. RESULTS: 121 papers were included for analyses. Data of 5 923 children with DCD were included (59.8% boys) and 23 619 Typically Developing (TD) children (45.8% boys). The mean (SD) age of the DCD group was 10.3y (1.2) and 9.3y (1.3) for the TD children. Moderate evidence was found for motor performance, executive functions, sensory processing and perceptions, cognitive functions and sports and leisure activities to be affected in children with DCD. CONCLUSION: Differences between the two groups varied per domain of functioning. This emphasizes the diversity present within children with DCD and provides a rationale for explaining the heterogeneity in this patient group. Yet, results highlight the potential involvement of all these domains and call for clinicians to be alert not only to examine motor skill difficulties but also other aspects of function. Results indicate the need to develop an individualized pre-intervention multi-dimensional assessment profile for each child with DCD. It also supports the important role that clinicians play in an interdisciplinary team to tackle the difficulties encountered by children with DCD.

Experiences and preferences of people with stroke and caregivers, around supports provided at the transition from hospital to home: a qualitative descriptive study.

BACKGROUND: Transitioning home from the structured hospital setting poses challenges for people with stroke (PWS) and their caregivers (CGs), as they navigate through complex uncertainties. There are gaps in our understanding of appropriate support interventions for managing the transition home. In this qualitative study, we explored the perspectives of PWS and their CGs regarding their support experiences and preferences during this period. METHODS: Between November 2022 and March 2023, and within six months of hospital discharge, audio-recorded, semi-structured interviews were conducted with PWS and CGs. All interviews were transcribed, imported into NVivo software, and analysed using reflexive thematic analysis. RESULTS: Sixteen interviews were conducted, nine with PWS and seven with CGs. Four themes relevant to their collective experiences and preferences were identified: (i) Need for tailored information-sharing, at the right time, and in the right setting; (ii) The importance of emotional support; (iii) Left in limbo, (iv) Inequity of access. Experiences depict issues such as insufficient information-sharing, communication gaps, and fragmented and inequitable care; while a multi-faceted approach is desired to ease anxiety and uncertainty, minimise delays, and optimise recovery and participation during transition. CONCLUSIONS: Our findings highlight that regardless of the discharge route, and even with formal support systems in place, PWS and families encounter challenges during the transition period. The experiences of support at this transition and the preferences of PWS and CGs during this important period highlights the need for better care co-ordination, early and ongoing emotional support, and equitable access to tailored services and support. Experiences are likely to be improved by implementing a partnership approach with improved collaboration, including joint goal-setting, between PWS, CGs, healthcare professionals and support organisations.

Acute Achilles tendon ruptures between 2002-2021: sustained increased incidence, surgical decline and prolonged delay to surgery-a nationwide study of 53 688 ruptures in Sweden.

Introduction: Given the lack of consensus on optimal treatment strategies for acute Achilles tendon rupture (ATR), understanding temporal trends, treatment choice and demographic characteristics is important. Previous research suggests increasing incidence with declining surgical treatment. Current trends in Sweden are not known. Hypothesis/purpose: To assess how incidence rates, treatment trends and time from injury to surgery (TTS) of ATR have changed between 2002 and 2021 in Sweden, with particular attention to changes since 2012. Study design: Descriptive epidemiology study. Methods: We conducted a nationwide register-based study including all inpatients and outpatients ≥18 years of age with an ATR between 2002 and 2021 in Sweden. Results: 53 688 ATRs (78.5% men) were identified during the study period. 15 045 patients (81.5% men) were surgically treated within 30 days. The long-term incidence rate for ATR injury increased by 45%, from 28.8 in 2002 to 41.7 in 2021 per 100 000 person-years (p<0.0001). In the last 5 years of the study, there was a significant, continuing increase in ATR incidence by 21%, from 34.4 in 2017 to 41.7 in 2021 per 100 000 person-years (p<0.0001). The surgical incidence rates decreased from 13.4 to 6.0 per 100 000 person-years (p<0.0001). TTS increased from 0.6 days in 2002 to 5.1 in 2021 (p<0.0001). Conclusion: The observed increase in incidence rates and decrease in surgical treatment of ATR emphasise the need for evidence-based treatment and rehabilitation protocols for non-operated patients of all ages. A significant increase in time from injury to surgery was observed throughout the study period.

The wide-awake local anesthesia no tourniquet (WALANT) technique in thumb injuries: a systematic review.

Human hands have a complex anatomical structure. The thumb, being an integral part of the hand, has an essential function in gripping. In this sense, thumb fractures account for 4% of all hand fractures (it may occur in association with fractures of the trapezium). The majority of hand fractures should be treated non-surgically and surgeons must avoid unnecessary surgery. Historically, hand surgery has used a combination of local/regional/general anaesthesia and a tourniquet. This study aims to carry out a systematic review to determine whether the WALANT technique is an advantageous alternative to conventional anaesthesia for surgical procedures on thumb injuries, in terms of patient function and pain. METHOD: We conducted a search in the following databases: Pubmed/Medline, EBSCOhost, Web of Science, Scopus, ScienceDirect and Google Scholar, using the equation "WALANT" OR "Wide Awake Local Anesthesia No Tourniquet" AND "thumb pathology". RESULTS: In five of the 584 articles included, two studied trapeziometacarpal osteoarthritis, one De Quervain's disease and the remaining two flexor injuries. WALANT showed good results in active movements, but with similar levels of pain between anaesthetics. Patients were more anxious during general anaesthesia, plus the fact that they were fasting and suspending medication. CONCLUSION: WALANT is a convenient and favourable option in several studies. It has been demonstrated the benefits in terms of return to function and pain.

Patellar articular overlap is better associated with patellar alignment during weight-bearing than traditional measures of patellar height.

BACKGROUND: A consequence of a high riding patella is reduced osseous stability and malalignment of the patella (i.e., lateral patellar tilt and displacement). Although quantification of patellar height is a routine part of the radiographic examination of the patellofemoral joint, it is not clear which measure of patellar height is best associated with patella alignment. HYPOTHESIS/PURPOSE: To determine if patellar articular overlap (PAO) is better associated with lateral patellar tilt and lateral patellar displacement compared to traditional measures of patellar height. STUDY DESIGN: Cross-sectional. METHODS: Magnetic resonance images were obtained from 50 female participants (21 with patellofemoral pain and 29 healthy controls) under loaded conditions (25-35% bodyweight) at 15-20 degrees of knee flexion. Measurements of lateral patellar tilt and displacement as well as the PAO, Insall-Salvati ratio (ISV), Caton Deschamps-index (CD-index), or the Blacburn Peel-index (BP-index) were obtained from sagittal and axial plane images. RESULTS: The PAO was found to significantly correlated with lateral patellar tilt (r = -0.77, p < 0.001). In contrast, the ISV, CD-index, or the BP-index were not found to be associated with lateral patellar tilt (r = 0.13, p = 0.34; r = -0.14, p = 0.33; r = -0.08, p = 0.56, respectively). Both the PAO and ISV were found to be significantly correlated with lateral patellar displacement (r = -0.52, p < 0.001; r = 0.43, p = 0.002, respectively). Conversely, the CD-index and BP-index were not found to be associated with lateral patellar displacement (r = 0.03 p = 0.83; r = 0.05 p = 0.74, respectively). CONCLUSION: Of the measures of patellar height evaluated, the PAO was found to provide the greatest association with lateral patellar tilt and displacement.

Multiple graphical views for automatically generating SQL for the MycoDiversity DB; making fungal biodiversity studies accessible.

Fungi is a highly diverse group of eukaryotic organisms that live under an extremely wide range of environmental conditions. Nowadays, there is a fundamental focus on observing how biodiversity varies on different spatial scales, in addition to understanding the environmental factors which drive fungal biodiversity. Metabarcoding is a high-throughput DNA sequencing technology that has positively contributed to observing fungal communities in environments. While the DNA sequencing data generated from metabarcoding studies are available in public archives, this valuable data resource is not directly usable for fungal biodiversity investigation. Additionally, due to its fragmented storage and distributed nature, it is not immediately accessible through a single user interface. We developed the MycoDiversity DataBase User Interface (https://mycodiversity.liacs.nl) to provide direct access and retrieval of fungal data that was previously inaccessible in the public domain. The user interface provides multiple graphical views of the data components used to reveal fungal biodiversity. These components include reliable geo-location terms, the reference taxonomic scientific names associated with fungal species and the standard features describing the environment where they occur. Direct observation of the public DNA sequencing data in association with fungi is accessible through SQL search queries created by interactively manipulating topological maps and dynamic hierarchical tree views. The search results are presented in configurable data table views that can be downloaded for further use. With the MycoDiversity DataBase User Interface, we make fungal biodiversity data accessible, assisting researchers and other stakeholders in using metabarcoding studies for assessing fungal biodiversity.

Real-world safety and effectiveness of intravenous fomepizole in patients with ethylene glycol and methanol poisoning in Japan: results of a 7-year post-marketing surveillance study.

BACKGROUND: Fomepizole is a competitive alcohol dehydrogenase inhibitor used for the treatment of ethylene glycol and methanol poisoning. We evaluated the safety and effectiveness of fomepizole in patients with ethylene glycol or methanol poisoning in Japan. RESEARCH DESIGN AND METHODS: This retrospective post-marketing surveillance study conducted in Japan registered patients who received fomepizole intravenous infusion per the package insert (January 2015-June 2022). Endpoints included adverse drug reactions/infections (ADRs), arterial blood pH, and treatment outcomes. RESULTS: Of 147 patients registered (91 institutions), 131 and 126 were included in the safety and effectiveness analysis sets, respectively. Mean age was 43.6 years, and 66.4% were male. Mean time from poison ingestion to treatment was 15.1 hours; 66.4% received concomitant hemodialysis. No serious ADRs were reported. ADRs were reported in seven patients; the most-reported ADR was vomiting (2.3%). Seven patients died, 105 survived without sequelae, and 19 survived with sequelae. Most common sequelae were renal failure or renal dysfunction. Mean arterial blood pH increased to 7.4 by 4 hours of treatment, remaining stable for 24 hours post-treatment. CONCLUSIONS: Fomepizole is well tolerated and helps improve clinical outcomes in patients with ethylene glycol or methanol poisoning in Japan. TRIAL REGISTRATION: Japanese Pharmaceutical Information Center (JapicCTI-152817).

Quantum Magnetism of the Iron Core in Ferritin Proteins-A Re-Evaluation of the Giant-Spin Model.

The electron-electron, or zero-field interaction (ZFI) in the electron paramagnetic resonance (EPR) of high-spin transition ions in metalloproteins and coordination complexes, is commonly described by a simple spin Hamiltonian that is second-order in the spin S: H=D[Sz2-SS+1/3+E(Sx2-Sy2). Symmetry considerations, however, allow for fourth-order terms when S ≥ 2. In metalloprotein EPR studies, these terms have rarely been explored. Metal ions can cluster via non-metal bridges, as, for example, in iron-sulfur clusters, in which exchange interaction can result in higher system spin, and this would allow for sixth- and higher-order ZFI terms. For metalloproteins, these have thus far been completely ignored. Single-molecule magnets (SMMs) are multi-metal ion high spin complexes, in which the ZFI usually has a negative sign, thus affording a ground state level pair with maximal spin quantum number mS = ±S, giving rise to unusual magnetic properties at low temperatures. The description of EPR from SMMs is commonly cast in terms of the 'giant-spin model', which assumes a magnetically isolated system spin, and in which fourth-order, and recently, even sixth-order ZFI terms have been found to be required. A special version of the giant-spin model, adopted for scaling-up to system spins of order S ≈ 103-104, has been applied to the ubiquitous iron-storage protein ferritin, which has an internal core containing Fe3+ ions whose individual high spins couple in a way to create a superparamagnet at ambient temperature with very high system spin reminiscent to that of ferromagnetic nanoparticles. This scaled giant-spin model is critically evaluated; limitations and future possibilities are explicitly formulated.

Emerging activated tungsten dust: Source, environmental behaviors, and health effects.

Fusion energy investigation has stepped to a new stage adopting deuterium and tritium as fuels from the previous stage concentrating hydrogen plasma physics. Special radiation safety issues would be introduced during this stage. In addition to industrial and military uses, tungsten is also regarded as the most promising plasma facing material for fusion reactors. During the operation of fusion reactors, tungsten-based plasma facing materials can be activated via neutron nuclear reaction. Meanwhile, activated tungsten dust can be produced when high-energy plasma interacts with the tungsten-based plasma facing materials, namely plasma wall interaction. Activated tungsten dust would be an emerging environmental pollutant with radiation toxicity containing various radionuclides in addition to the chemical toxicity of tungsten itself. Nonetheless, the historical underestimation of its environmental availability has led to limited research on tungsten compared to other environmental contaminants. This paper presents the first systematic review on the safety issue of emerging activated tungsten dust, encompassing source terms, environmental behaviors, and health effects. The key contents are as follows: 1) to detail the source terms of activated tungsten dust from aspects of tungsten basic properties, generation mechanism, physical morphology and chemical component, radioactivity, as well as potential release pathways, 2) to illustrate the environmental behaviors from aspects of atmospheric dispersion and deposition, transformation and migration in soil, as well as plant absorption and distribution, 3) to identify the toxicity and health effects from aspects of toxicity to plants, distribution in human body, as well as health effects by radiation and chemical toxicity, 4) based on the research progress, research and development issues needed are also pointed out to better knowledge of safety issue of activated tungsten dust, which would be beneficial to the area of fusion energy and ecological impact caused by the routine tungsten related industrial and military applications.