Mitigation measures against Coronavirus Disease 2019 (COVID-19) in overnight faith-based camps: summer 2021.

OBJECTIVE: In this study, we describe community-based nonpharmaceutical interventions (NPIs) incorporated into COVID-19 mitigation protocols, and SARS-CoV-2 incidence at five faith-based summer camps in the US. STUDY DESIGN: Retrospective cohort study. METHODS: Six southeastern states within the United States (13 sites) were assessed from May 30 to August 14, 2021 (13 sites; N = 13,132; May-August 2021). Camp mitigation policies and NPIs (including masking, vaccinations, meal arrangements, physical distancing, pre-arrival testing, symptom screening, quarantine/isolation, and ventilation upgrades), and SARS-CoV-2 infections were tracked at each site. RESULTS: The symptomatic primary case attack rate was 24.7 (range: 0.0-120.0) cases per 100,000 people per week. Fewer infections were observed in camps with greater mitigation protocols. CONCLUSION: These findings suggest that nonpharmaceutical mitigation can promote stable access to youth programs for historically vaccine-hesitant subgroups. Policy recommendations for nonpharmaceutical interventions to prevent respiratory viral transmission in overnight youth faith-based camp settings may include outdoor activities, accessible symptomatic tests, prearrival testing, indoor mask use, small cohorts, physical distancing, and protocols to minimize staff exposures during time off.

Treatment Outcomes of Stereotactic Ablative Body Radiotherapy on Extra-cranial Oligometastatic and Oligoprogressive Breast Cancer: Mature Results from a Single Institution Experience.

AIMS: Evidence shows stereotactic ablative body radiotherapy (SABR) is used as a non-invasive ablative therapy in the treatment of multisite oligometastatic (OM) and oligoprogressive (OP) diseases originating from metastatic breast cancer. This study aims to report the treatment outcomes and to investigate what factors that are prognostic in terms of local control, progression-free survival (PFS) and overall survival (OS) in patients receiving SABR for extracranial OM and OP diseases originating from metastatic breast cancer. MATERIALS AND METHODS: A retrospective review on treatment records of patients with OM and OP from metastatic breast cancer who underwent SABR at a single was carried out. SABR was performed with daily image-guided radiotherapy (IGRT) using a dedicated robotic SABR machine. Local control, PFS and OS were calculated using Kaplan-Meier statistics and the post-treatment toxicity data was scored following the CTCAE v4.0 protocol. Univariate and multivariate Cox regression tests were used in the subgroup analysis of prognostic factors on PFS and OS including patients' age, types of follow-up imaging (staging CT only vs whole-body MR/PET), metastases status (OM vs OP), primary breast cancer tumour grade, hormone receptors (ER/PR/HER2) status, change of systemic treatments at SABR, number of metastases, SABR treatment sites and doses. RESULTS: 56 metastatic breast cancer patients (38 patients with OM and 18 patients with OP) were involved in this retrospective review. The median follow-up was 35.6 months (range 4.0-132.9 months). The estimated local control at 1 , 2 and 5 years were 90.9%, 88.7% and 88.7%, respectively. The estimated median PFS was 19.2 months (95%CI 10.3-28.1 months); the PFS at 1, 2 and 5 years were 63.3%, 44.4% and 33.2%. The estimated OS at 1, 2 and 5 years were 98.0%, 91.9% and 74.3%, respectively with the estimated median OS of 105.1 months (95%CI 51.5-158.7 months). The vast majority of patients tolerated the treatment well with the commonest acute side effects as grade 1 fatigue. There were no statistically significant factors found in OS regression analysis. The types of follow-up imaging, metastases status, oestrogen receptor status, and number of metastases for SABR were statistically significant factors (p < 0.05) in the multivariate Cox regression analysis on PFS. CONCLUSION: There are limited studies published on the efficacy and post-treatment toxicities of metastatic breast cancer OM and OP SABR with adequate length of follow-up. This study confirmed that SABR was a safe, non-invasive treatment option for patients with extracranial OM and OP diseases originated from primary breast cancer in terms of the acceptable post-treatment toxicities.

Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel.

BACKGROUND: In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel. LABORATORY STRUCTURE AND RESOURCE: The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists. LABORATORY RESULTS: Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started. CONCLUSIONS: Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

Evaluation of the Efficacy of Doxycycline, Ciprofloxacin, Levofloxacin, and Co-trimoxazole Using In Vitro and In Vivo Models of Q Fever.

Q fever, caused by the intracellular pathogen Coxiella burnetii, is traditionally treated using tetracycline antibiotics, such as doxycycline. Doxycycline is often poorly tolerated, and antibiotic-resistant strains have been isolated. In this study, we have evaluated a panel of antibiotics (doxycycline, ciprofloxacin, levofloxacin, and co-trimoxazole) against C. burnetii using in vitro methods (determination of MIC using liquid and solid media; efficacy assessment in a THP cell infection model) and in vivo methods (wax moth larvae and mouse models of infection). In addition, the schedule for antibiotic treatment has been evaluated, with therapy initiated at 24 h pre- or postchallenge. Both doxycycline and levofloxacin limited overt clinical signs during treatment in the AJ mouse model of aerosol infection, but further studies are required to investigate the possibility of disease relapse or incomplete bacterial clearance after the antibiotics are stopped. Levofloxacin was well tolerated and therefore warrants further investigation as an alternative to the current recommended treatment with doxycycline.

IL-1α Modulates IFN-γ-Induced Production of CXCL9/MIG during Herpes Simplex Virus Type-1 Corneal Infection.

PURPOSE: Investigating the modulation of neutrophil production of MIG and IP-10 during the inflammatory response to HSV-1 infection. MATERIALS AND METHODS: An ex vivo model of human corneal infection by HSV-1 was used for this study. This model permits the study of cytokine production by human corneal buttons in the presence, or absence, of gradient purified human neutrophils, under conditions of HSV-1 infection. All experimental samples were stimulated with a baseline concentration of recombinant human IFN-γ at 1 ng/mL. The relative levels of production for 12 pro-inflammatory mediators were screened using a multi-analyte ELISA assay. Neutrophil production of chemokines MIG and IP-10, under conditions of IFN-γ and/or HSV-1 stimulation were measured by quantitative ELISA. Lastly, antibody neutralization (goat IgG anti-human IL-1α, 2 µg/mL) of de novo production of IL-1α by corneal tissue was performed to investigated the effect on MIG and IP-10 production in the ex vivo model for HSV-1 infection. RESULTS: Four of the 12 pro-inflammatory mediators screened (IL-8, IL-6, IL-1α and IL-1ß) demonstrated elevated levels of production during corneal cell infection with HSV-1 and communication with neutrophils. Neutrophils were demonstrated to produce significant levels of both MIG and IP-10 under conditions of IFN-γ stimulation, and production of MIG was further upregulated by co-stimulation with IFN-γ and HSV-1. Neutralization of de novo IL-1α production in the model resulted in increased production of the chemokine production MIG but had no observable effect on IP-10 production. CONCLUSIONS: Our data provide evidence demonstrating the potential for expression patterns of MIG and IP-10 to be modulated by IL-1α, during the inflammatory response to HSV-1 corneal infection. Both corneal cells and neutrophils contribute to the production of T cell recruiting chemokines. However, IL-1α has the potential to upregulate MIG production by corneal cells while down-regulating MIG production by neutrophils.

Evaporation and Electrowetting of Sessile Droplets on Slippery Liquid-Like Surfaces and Slippery Liquid-Infused Porous Surfaces (SLIPS).

Sessile droplet evaporation underpins a wide range of applications from inkjet printing to coating. However, drying times can be variable and contact-line pinning often leads to undesirable effects, such as ring stain formation. Here, we show voltage programmable control of contact angles during evaporation on two pinning-free surfaces. We use an electrowetting-on-dielectric approach and Slippery Liquid-Infused Porous (SLIP) and Slippery Omniphobic Covalently Attached Liquid-Like (SOCAL) surfaces to achieve a constant contact angle mode of evaporation. We report evaporation sequences and droplet lifetimes across a broad range of contact angles from 105°-67°. The values of the contact angles during evaporation are consistent with expectations from electrowetting and the Young-Lippman equation. The droplet contact areas reduce linearly in time, and this provides estimates of diffusion coefficients close to the expected literature value. We further find that the total time of evaporation over the broad contact angle range studied is only weakly dependent on the value of the contact angle. We conclude that on these types of slippery surfaces, droplet lifetimes can be predicted and controlled by the droplet's volume and physical properties (density, diffusion coefficient, and vapor concentration difference to the vapor phase) largely independent of the precise value of contact angle. These results are relevant to applications, such as printing, spraying, coating, and other processes, where controlling droplet evaporation and drying is important.

Complex Clinical Decision-Making Process of Re-Irradiation.

As patients live longer with their cancer as a result of more effective treatment, recurrences and second malignancies in a previously irradiated field are an increasing challenge. The technical advances that enable high-dose radiation to limited volumes, excluding critical normal tissues, have increased the use of re-irradiation for many tumour sites. Minimising the volume, selecting patients with good performance status, negative metastatic screening and longer disease-free intervals are important principles. Despite this there is a narrow therapeutic window, and careful consideration with open discussion, including the patient, of the probable benefit and the implications of potential toxicities will always be essential. In this overview we evaluate the various radiobiological factors that need to be considered for re-irradiation, tissue recovery and dose tolerances in the setting of re-irradiation and summarise the available literature to guide clinicians in their decision-making for re-irradiation to primary and metastatic site/s of disease.

Botulinum toxin in the management of temporomandibular disorders: a systematic review.

The aim of this review was to critically investigate and assess the evidence relating to the use and efficacy of botulinum toxin (BTX) in the management of temporomandibular joint disorders (TMD) and masticatory myofascial pain. A comprehensive search was conducted of PubMed, Scopus, Embase, and Cochrane CENTRAL, to find relevant studies from the last 30 years up to the end of July 2018. Seven were identified. Three showed a significant reduction in pain between the BTX and placebo groups and one showed a clinical, but not a significant, difference. In one that compared BTX with another novel treatment, myofascial pain reduced equally in both groups, and in the remaining two there was no significant difference in pain reduction between the BTX and control groups. Of the four studies that assessed mouth opening, two reported that BTX had resulted in a slight improvement; one reported no improvement, and the other a worsening of the condition. A meta-analysis was not possible because of the considerable variation in the studies' designs, the heterogeneity between the groups, and the different assessment tools used. Despite showing benefits, consensus on the therapeutic benefit of BTX in the management of myofascial TMD is lacking. Further randomised controlled trials with larger sample sizes, minimal bias, and longer follow-up periods are now needed.

Precision and accuracy of a point-of-care glucometer in horses and the effects of sample type.

Point-of-care glucometry is used commonly in clinical and research settings; however, accuracy and precision of this method are concerns. The objectives of this study were to determine the accuracy of glucometry in adult horses and the precision of duplicate measurements. Blood samples were collected from 62 horses into one plain syringe, one EDTA tube and three fluoride oxalate (FO) tubes. Immediately after collection, glucose concentrations in whole blood were determined, in duplicate, by glucometry from the syringe (plain whole blood [WB] group), EDTA tube (EDTA group) and one FO tube (FO group). One FO sample was used to measure plasma glucose concentration by a laboratory chemistry analyser (LAB group) ≤1 h after collection. The third FO tube was used to measure plasma glucose concentration by glucometry after 3 h storage (FO3hr group). Adequate precision was present for all groups (coefficient of variation: 0.7-3.5%) except WB (5.5-9.4%). Between groups, correlations were significant (P < 0.05; except for WB-EDTA), varied with group comparison, and tended to be lowest for comparisons involving WB. Mean bias was lowest for WB-LAB and greatest for FO-LAB and FO3hr-LAB; however, the limits of agreement were ≥4.65 mmol/L for WB-LAB and ≤2.75 mmol/L for most other comparisons. For the glucometer used, performance was influenced by sample type: WB was unsuitable, while FO or EDTA samples resulted in adequate precision and accuracy, provided under-estimation of glucose concentrations is accounted for by using method-specific reference ranges. Glucometer performance and optimal sample type(s) should be determined prior to use in horses.

Nonrestorative Treatments for Caries: Systematic Review and Network Meta-analysis.

The goal of nonrestorative or non- and microinvasive caries treatment (fluoride- and nonfluoride-based interventions) is to manage the caries disease process at a lesion level and minimize the loss of sound tooth structure. The purpose of this systematic review and network meta-analysis was to summarize the available evidence on nonrestorative treatments for the outcomes of 1) arrest or reversal of noncavitated and cavitated carious lesions on primary and permanent teeth and 2) adverse events. We included parallel and split-mouth randomized controlled trials where patients were followed for any length of time. Studies were identified with MEDLINE and Embase via Ovid, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews. Pairs of reviewers independently conducted the selection of studies, data extraction, risk-of-bias assessments, and assessment of the certainty in the evidence with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Data were synthesized with a random effects model and a frequentist approach. Forty-four trials (48 reports) were eligible, which included 7,378 participants and assessed the effect of 22 interventions in arresting or reversing noncavitated or cavitated carious lesions. Four network meta-analyses suggested that sealants + 5% sodium fluoride (NaF) varnish, resin infiltration + 5% NaF varnish, and 5,000-ppm F (1.1% NaF) toothpaste or gel were the most effective for arresting or reversing noncavitated occlusal, approximal, and noncavitated and cavitated root carious lesions on primary and/or permanent teeth, respectively (low- to moderate-certainty evidence). Study-level data indicated that 5% NaF varnish was the most effective for arresting or reversing noncavitated facial/lingual carious lesions (low certainty) and that 38% silver diamine fluoride solution applied biannually was the most effective for arresting advanced cavitated carious lesions on any coronal surface (moderate to high certainty). Preventing the onset of caries is the ultimate goal of a caries management plan. However, if the disease is present, there is a variety of effective interventions to treat carious lesions nonrestoratively.

Development of a three-wave far-infrared laser interferometry and polarimetry diagnostic system for the C-2W field-reversed configuration plasmas.

Great advancements in modern field-reversed configuration (FRC) experiments motivated the development of a 14-chord three-wave far infrared (FIR) laser interferometry and polarimetry diagnostic system, which can provide simultaneous high temporal resolution measurements of density and Faraday rotation profiles with high accuracy. The unique challenges facing FIR diagnostics in high beta FRC plasmas are the extremely small (<0.5°) Faraday rotation angles, and severe laser beam refraction effects due to high density gradient and choice of long wavelength. The diagnostic system design and development are described with methods to overcome the challenges, and initial experimental data are also presented.

Evidence-based dentistry skill acquisition by second-year dental students.

INTRODUCTION: Identification and assessment of Evidence-based dentistry (EBD) outcomes have been elusive. Our objective was to describe EBD skill acquisition during the second (D2) year of pre-doctoral dental education and student competency at the end of the year. METHODS: The first and fourth (final) curricular-required EBD Exercises (ie, application of the first 4 steps of the 5-Step evidence-based practice process applied to a real or hypothetical situation) completed by D2 students (n = 151) during 2014-2015 and 2015-2016 were evaluated to measure skill acquisition through use of a novel rubric with measures of performance from novice to expert. Exercises were evaluated on the performance for each step, identification of manuscript details and reflective commentary on manuscript components. Changes in performance were evaluated using the chi-square test for trend and the Wilcoxon signed-rank test. RESULTS: Seventy-eight per cent of students scored competent or higher on the Ask step at the beginning of the D2 year; scores improved with 58% scoring proficient or expert on the fourth Exercise (P < .001). Most students were advanced beginners or higher in the Acquire, Appraise and Apply steps at the beginning of the D2 year, with minimal growth observed during the year. Identification of manuscript details improved between the first and fourth Exercises (P = .015); however, depth of commentary skills did not change. DISCUSSION: Unlike previous investigations evaluating EBD knowledge or behaviour in a testing situation, we evaluated skill acquisition using applied Exercises. CONCLUSION: Consistent with their clinical and scientific maturity, D2 students minimally performed as advanced beginners at the end of their D2 year.

Chair based exercise in community settings: a cluster randomised feasibility study.

BACKGROUND: Some older people who find standard exercise programmes too strenuous may be encouraged to exercise while remaining seated - chair based exercises (CBE). We previously developed a consensus CBE programme (CCBE) following a modified Delphi process. We firstly needed to test the feasibility and acceptability of this treatment approach and explore how best to evaluate it before undertaking a definitive trial. METHODS: A feasibility study with a cluster randomised controlled trial component was undertaken to 1. Examine the acceptability, feasibility and tolerability of the intervention and 2. Assess the feasibility of running a trial across 12 community settings (4 day centres, 4 care homes, 4 community groups). Centres were randomised to either CCBE, group reminiscence or usual care. Outcomes were collected to assess the feasibility of the trial parameters: level of recruitment interest and eligibility, randomisation, adverse events, retention, completion of health outcomes, missing data and delivery of the CCBE. Semi- structured interviews were conducted with participants and care staff following the intervention to explore acceptability. RESULTS: 48% (89 out of 184 contacted) of eligible centres were interested in participating with 12 recruited purposively. 73% (94) of the 128 older people screened consented to take part with 83 older people then randomised following mobility testing. Recruitment required greater staffing levels and resources due to 49% of participants requiring a consultee declaration. There was a high dropout rate (40%) primarily due to participants no longer attending the centres. The CCBE intervention was delivered once a week in day centres and community groups and twice a week in care homes. Older people and care staff found the CCBE intervention largely acceptable. CONCLUSION: There was a good level of interest from centres and older people and the CCBE intervention was largely welcomed. The trial design and governance procedures would need to be revised to maximise recruitment and retention. If the motivation for a future trial is physical health then this study has identified that further work to develop the CCBE delivery model is warranted to ensure it can be delivered at a frequency to elicit physiological change. If the motivation for a future trial is psychological outcomes then this study has identified that the current delivery model is feasible. TRIAL REGISTRATION: ISRCTN27271501 . Date registered: 30/01/2018.

Feasibility and Patient Perceptions of Video Declarations Regarding End-of-Life Decisions by Hospitalized Patients.

BACKGROUND: A videotaped declaration by patients of their advance care planning preferences could be an opportunity to supplement advance directive forms and be a source of information for family, caregivers, and clinicians, yet research is needed to examine the content and acceptability of making declarations among patients. OBJECTIVE: To evaluate the content and acceptability of 'video declarations': the process of patients videotaping themselves describing their advance care planning preferences. DESIGN: We showed a brief video describing three approaches to end-of-life care and then invited participants to use an iPad to videotape themselves making a declaration about their wishes. SETTING/SUBJECTS: Hospitalized patients from a large urban U.S. safety net hospital. MEASUREMENTS: We interviewed participants about the acceptability of the declaration process. Declarations were transcribed and coded by a team, with multiple stakeholder input. RESULTS: There were 16 participants; mean age was 60 (SD = 14) years. One participant declined. Out of 15 declarations, most were able to express their wishes for CPR (n = 12) and intubation (n = 13). Participants frequently discussed their family structure (n = 11), religious/spiritual well-being (n = 8), legacy/dignity issues (n = 6), and physical symptoms (n = 6). Nine declarations had directives judged to be unclear. The majority (66%) thought that this process was quite a bit or extremely helpful. CONCLUSIONS: Findings show that asking hospitalized patients to make videos describing their advance care planning preferences was feasible and acceptable. While the majority described their wishes around CPR and intubation, a fair amount of uncertainty remained. Further research is needed to support patients in describing their wishes clearly and test the effectiveness of video declarations to promote care concordant with preferences.

Time of rumen fluid collection relative to feeding alters in vitro fermentation gas parameters.

The objective of this study was to determine the effect of time of rumen fluid collection relative to feeding on gas production kinetics for in vitro rumen fermentation. Three ruminally cannulated Holstein heifers were rumen fluid donors. Feed was removed from heifers 12 h prior to feeding, rumen fluid was collected from each heifer before feeding (0 h), and at 2, 4, and 6 h after feeding, repeated on three separate incubation days. Buffered rumen fluid (100 mL) was incubated in 250-mL bottles containing 1.4 g of dried TMR, in duplicate for each heifer at each collection time. All bottles were incubated for 24 h at 39°C and constant agitation (60 rpm), and capped with monitors to capture temperature and pressure every 15 min (RF1, Ankom Technology, Macedon, NY). At the end of incubation, final pH was recorded. Gas data were fit with nonlinear regression comparison of fit in GraphPad Prism 7 to find best fit regression. The formula with best fit was as follows: y = Vm(1 - (e(-Kd(x - lag)))), where y is gas produced at time X (mmol), Vm is the asymptotic gas production (mmol), Kd indicates the fractional rate of gas production (mmol/h), X is time (h), and lag refers to the lag time before the start of fermentation (h) as indicated by positive gas production (R 2 = 0.98). Data were analyzed using PROC GLIMMIX of SAS, with donor as the experimental unit and day as the random blocking factor; significance is defined as P ≤ 0.05. Time of rumen fluid collection significantly affected gas production kinetics (lag P = 0.01, Vm P = 0.03, Kd P <0.0001). Gas production was highest in fermenter units fed with rumen fluid collected 2-h post-feeding. Fractional rate of fermentation (Kd) was fastest in rumen fluid collected at 0 h. Lag time was longest in rumen fluid collected at 4-h post-feeding and slowest in rumen fluid collected at 0 h. Time of rumen fluid collection did not alter final pH. Our findings suggest that gas production is maximized when rumen fluid is collected between 2 and 4 h after feeding.

Time of rumen fluid collection relative to feeding alters in vitro fermentation volatile fatty acid production.

The objective of this study was to determine the effect of time of rumen fluid collection relative to feeding on volatile fatty acid (VFA) production for in vitro rumen fermentation. Three ruminally cannulated Holstein heifers were used as rumen fluid donors. Feed was removed from heifers 12 h prior to feeding, rumen fluid was collected from each heifer before feeding (0 h), and at 2, 4, and 6 h after feeding, repeated on three separate incubation days. Buffered rumen fluid (100 mL) was incubated in 250-mL bottles containing 1.4 g of dried TMR, in duplicate for each heifer at each collection time. All bottles were incubated for 24 h at 39°C and constant agitation (60 rpm), and capped with monitors to capture temperature and pressure every 15 min (RF1, Ankom Technology, Macedon, NY). At the end of incubation, final pH and a sample of rumen fluid were collected for VFA and ammonia nitrogen. Data were analyzed using PROC GLIMMIX of SAS, with donor as the experimental unit and day as the random blocking factor; significance is defined as P ≤ 0.05. Time of rumen fluid collection significantly affected acetate (mmol/liter; P = 0.0004), propionate (mmol/liter; P = 0.02), isobutyrate (mmol/liter; P < 0.0001), valerate (mmol/liter; P = 0.004), isovalerate (mmol/liter; P < 0.00001), and total VFA concentrations (mmol/liter; P = 0.004). All VFA relative proportions were altered due to time of rumen fluid collection (P < 0.02). VFA production was highest when rumen fluid was collected 4-h post-feeding. There was little to no effect on pH. Our findings suggest that VFA production is maximized when rumen fluid is collected between 2 and 4 h after feeding.

The efficacy of HI-6 DMS in a sustained infusion against percutaneous VX poisoning in the guinea-pig.

Post-exposure nerve agent treatment usually includes administration of an oxime, which acts to restore function of the enzyme acetylcholinesterase (AChE). For immediate treatment of military personnel, this is usually administered with an autoinjector device, or devices containing the oxime such as pralidoxime, atropine and diazepam. In addition to the autoinjector, it is likely that personnel exposed to nerve agents, particularly by the percutaneous route, will require further treatment at medical facilities. As such, there is a need to understand the relationship between dose rate, plasma concentration, reactivation of AChE activity and efficacy, to provide supporting evidence for oxime infusions in nerve agent poisoning. Here, it has been demonstrated that intravenous infusion of HI-6, in combination with atropine, is efficacious against a percutaneous VX challenge in the conscious male Dunkin-Hartley guinea-pig. Inclusion of HI-6, in addition to atropine in the treatment, improved survival when compared to atropine alone. Additionally, erythrocyte AChE activity following poisoning was found to be dose dependent, with an increased dose rate of HI-6 (0.48mg/kg/min) resulting in increased AChE activity. As far as we are aware, this is the first study to correlate the pharmacokinetic profile of HI-6 with both its pharmacodynamic action of reactivating nerve agent inhibited AChE and with its efficacy against a persistent nerve agent exposure challenge in the same conscious animal.

The Effects of Cavity Preparation and Composite Resin on Bond Strength and Stress Distribution Using the Microtensile Bond Test.

OBJECTIVES: To evaluate the effect of flowable bulk-fill or conventional composite resin on bond strength and stress distribution in flat or mesio-occlusal-distal (MOD) cavity preparations using the microtensile bond strength (µTBS) test. METHODS: Forty human molars were divided into two groups and received either standardized MOD or flat cavity preparations. Restorations were made using the conventional composite resin Z350 (Filtek Z350XT, 3M-ESPE, St Paul, MN, USA) or flowable bulk-fill (FBF) composite resin (Filtek Bulk Fill Flowable, 3M-ESPE). Postgel shrinkage was measured using the strain gauge technique (n=10). The Z350 buildup was made in two increments of 2.0 mm, and the FBF was made in a single increment of 4.0 mm. Six rectangular sticks were obtained for each tooth, and each section was used for µTBS testing at 1.0 mm/min. Polymerization shrinkage was modeled using postgel shrinkage data. The µTBS data were analyzed statistically using a two-way analysis of variance (ANOVA), and the postgel shrinkage data were analyzed using a one-way ANOVA with Tukey post hoc test. The failure modes were analyzed using a chi-square test (α=0.05). RESULTS: Our results show that both the type of cavity preparation and the composite resin used affect the bond strength and stress distribution. The Z350 composite resin had a higher postgel shrinkage than the FBF composite resin. The µTBS of the MOD preparation was influenced by the type of composite resin used. Irrespective of composite resin, flat cavity preparations resulted in higher µTBS than MOD preparations ( p<0.001). Specifically, in flat-prepared cavities, FBF composite resin had a similar µTBS relative to Z350 composite resin. However, in MOD-prepared cavities, those with FBF composite resin had higher µTBS values than those with Z350 composite resin. Adhesive failure was prevalent for all tested groups. The MOD preparation resulted in higher shrinkage stress than the flat preparation, irrespective of composite resin. For MOD-prepared cavities, FBF composite resin resulted in lower stress than Z350 composite resin. However, no differences were found for flat-prepared cavities. CONCLUSIONS: FBF composite resin had lower shrinkage stress than Z350 conventional composite resin. The µTBS of the MOD preparation was influenced by the composite resin type. Flat cavity preparations had no influence on stress and µTBS. However, for MOD preparation, composite resin with higher shrinkage stress resulted in lower µTBS values.

An approach on defining competency in evidence-based dentistry.

INTRODUCTION: Assessment of evidence-based dentistry (EBD) knowledge and behaviour is hampered by lack of explicit competency criteria. This void impedes instructional design and assessment of student growth during the educational process. METHODS: Knowledge and cognitive domains supporting educational objectives in a pre-doctoral dental programme were identified for each level of the EBD five-step process. We articulated educational objectives with behavioural expectations for each level of skill acquisition at each step of the EBD process. Outcome evaluation criteria identify students' progressive level of skill acquisition from novice to expert. RESULTS: The educational objectives, type of knowledge, and nature of the cognitive process supporting these objectives are presented for each step of the EBD process. For example, educational objectives of the "Ask" step include (i) to construct a question from the patient presentation and knowledge limitations that addresses the clinical problem and (ii) to articulate the Problem, Intervention/Exposure, Comparison, Outcome (PICO) components. Achievement of these objectives requires both factual information regarding the PICO format and the cognitive process of understanding. Educational outcome criteria consistent with a competent clinician include clear articulation of the PICO with identifiable pieces that relate to the clinical situation. DISCUSSION: Assessment strategies for progression towards EBD competency are limited due to the complexity associated with evaluating EBD knowledge and behaviours. To evaluate performance, the EBD academic community must define competency expectations for entry into unsupervised general dental practice. CONCLUSION: This framework offers measurable outcome evaluation criteria to initiate a conversation with academic peers regarding current gaps in EBD assessment.