Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength.

High temperatures exert a significant influence on the mechanical and fluid flow properties of rocks and minerals. In crystalline rocks, differential thermal expansion of minerals is known to induce microfracture damage leading to changes in bulk volume and tensile strength. Here we report new data from thermally treated core samples of Devon Granite in order to constrain the interplay between tensile strength and thermally-induced damage with respect to the background mineralogy. A series of core samples was cyclically heated at temperatures ranging from 25 to 800 °C, with P-wave velocity and porosity measured after each cycle. Tensile strength decreased significantly from 9 MPa to less than 3 MPa as thermal treatment increased from 25 to 800 °C. The mechanical data were then compared to fracture density values obtained by optical maps of microfracture damage to assess the quantity and degree of linkage of intergranular and intragranular fractures using the FraqPaQ toolbox. The fracture density increased from 0.02 m m - 2 to 2.0 m m - 2 which is consistent with results obtained from direct physical parameters as calculated from elastic wave data. We conclude that the combined effects of thermal expansion and the α - ß phase transition within quartz crystals has a pronounced effect on tensile strength.

Positive Retrospective SARS-CoV-2 Testing in a Case of Acute Respiratory Distress Syndrome of Unknown Etiology.

In order to elucidate the cause of acute respiratory distress syndrome of unknown etiology in a pre-pandemic patient, molecular techniques were used for detection of SARS-CoV-2. We used a SARS-CoV-2 nucleocapsid protein immunofluorescence stain to retrospectively identify an individual with diffuse alveolar damage on autopsy histology who had negative respiratory virus panel results in February, 2020, in Birmingham, Alabama. In situ hybridization for SARS-CoV-2 RNA revealed evidence of widespread multiorgan SARS-CoV-2 infection. This death antecedes the first reported death of a State of Alabama resident diagnosed with SARS-CoV-2 by 26 days.

Regional anaesthesia quality indicators for adult patients undergoing non-cardiac surgery: a systematic review.

Improvement in healthcare delivery depends on the ability to measure outcomes that can direct changes in the system. An overview of quality indicators within the field of regional anaesthesia is lacking. This systematic review aims to synthesise available quality indicators, as per the Donabedian framework, and provide a concise overview of evidence-based quality indicators within regional anaesthesia. A systematic literature search was conducted using the databases MEDLINE, Embase, CINAHL and Cochrane from 2003 to present, and a prespecified search of regional anaesthesia society websites and healthcare quality agencies. The quality indicators relevant to regional anaesthesia were subdivided into peri-operative structure, process and outcome indicators as per the Donabedian framework. The methodological quality of the indicators was determined as per the Oxford Centre for Evidence-Based Medicine's framework. Twenty manuscripts met our inclusion criteria and, in total, 68 unique quality indicators were identified. There were 4 (6%) structure, 12 (18%) process and 52 (76%) outcome indicators. Most of the indicators were related to the safety (57%) and effectiveness (19%) of regional anaesthesia and were general in nature (60%). In addition, most indicators (84%) were based on low levels of evidence. Our study is an important first step towards describing quality indicators for the provision of regional anaesthesia. Future research should focus on the development of structure and process quality indicators and improving the methodological quality and usability of these indicators.

Does replacement of missing dental units with resin-retained bridges improve oral health-related quality of life?: A systematic review.

OBJECTIVES: To assess the current literature in regard to two research questions: METHODS: Systematic review following the Preferred Reporting Items for Systemic Reviews and Meta-Analysis statement (PRISMA) statement. DATA/SOURCES: MEDLINE via Ovid, Scopus, PsycINFO via Ovid, Cochrane Library, Web of Science and clinicaltrials.gov were searched (Jan 1980 to Nov 2018) using high-level MeSH terms for studies published in English, investigating OHRQoL, using valid indices. RISK OF BIAS (ROB): Determined using Cochrane RoB tool and ROBINS-I. EVIDENCE CERTAINTY: Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group tool. RESULTS: Study Selection: 280 articles were identified; 270 were excluded after abstract review, 7 after examining full text, leaving 3 articles (3 studies, 188 participants, 172 analysed) included in this review; one RCT and two observational studies. Synthesis of results: There was significant heterogeneity and no meta-analysis was possible. Description of effect: One pre-post study design found provision of 2-unit RRBs significantly reduced the total OHIP-49 score (effect size 0.67), compared with an untreated control. One case-control study found no differences in total OHIP-49 between individuals treated with RRB or implant-supported crown. Major complications related to a worse OHRQoL. DISCUSSION: Quality of evidence: The overall RoB assessments were one study "some concerns" and two studies "serious". The GRADE assessment was "moderate" for one comparison and "low" for two comparisons. CLINICAL SIGNIFICANCE: A 2-unit cantilever RRB to replace one missing tooth probably results in a large improvement in oral health-related quality of life. Clinicians should ensure that the correct investigations and design of prosthesis are prescribed to help reduce any failures that may impact on OHRQoL.

Socioeconomic Variation in the association between Malocclusion and Oral Health Related Quality of Life.

OBJECTIVES: Oral health related quality of life (OHRQoL) has been linked to malocclusion. We aimed (a) to investigate the association between malocclusion and OHRQoL among children, and (b) to examine whether this association varied by socioeconomic status. METHODS: Cross-sectional analysis of data for 4,217 children aged 12 & 15 years, who participated in the 2013 Children Dental Health Survey (CDHS); a nationally representative survey of children in England, Wales, and Northern Ireland. Malocclusion was determined using the modified Index of Orthodontic Treatment Need (IOTN). OHRQoL was measured using the Child Oral Impacts on Daily Performance (Child-OIDP). For socioeconomic status, we used the pupils' eligibility for free school meals (FSM) and Index of Multiple Deprivation (IMD). Adjusted marginal effects were estimated controlling for confounding variables. Separate analyses were carried out for the two age groups. RESULTS: Malocclusion was associated with 6% and 15% increases in the probability of reporting negative impact of OHRQoL for 12- and 15-year olds respectively, which was significant for 15-year olds (marginal effect=0.15, 95% CI=0.08-0.22). Malocclusion was associated with the prevalence of oral impacts for 12 year olds (marginal effect=0.1, 95% CI=0.02-0.17) and 15-year olds (marginal effect=0.2, 95% CI 95%=0.13-0.28) not eligible for FSM and for 15-year olds in the most (marginal effect=0.2, 95% CI=0.1-0.29) and least (marginal effect=0.26, 95% CI=0.13-0.4) deprived IMD quintiles. CONCLUSIONS: Malocclusion was associated with impacts on OHRQoL for 15-year olds. There was evidence of a relationship between SES, malocclusion and OHRQoL.

Structural Determinants and Children's Oral Health: A Cross-National Study.

Much research on children's oral health has focused on proximal determinants at the expense of distal (upstream) factors. Yet, such upstream factors-the so-called structural determinants of health-play a crucial role. Children's lives, and in turn their health, are shaped by politics, economic forces, and social and public policies. The aim of this study was to examine the relationship between children's clinical (number of decayed, missing, and filled teeth) and self-reported oral health (oral health-related quality of life) and 4 key structural determinants (governance, macroeconomic policy, public policy, and social policy) as outlined in the World Health Organization's Commission for Social Determinants of Health framework. Secondary data analyses were carried out using subnational epidemiological samples of 8- to 15-y-olds in 11 countries ( N = 6,648): Australia (372), New Zealand (three samples; 352, 202, 429), Brunei (423), Cambodia (423), Hong Kong (542), Malaysia (439), Thailand (261, 506), United Kingdom (88, 374), Germany (1498), Mexico (335), and Brazil (404). The results indicated that the type of political regime, amount of governance (e.g., rule of law, accountability), gross domestic product per capita, employment ratio, income inequality, type of welfare regime, human development index, government expenditure on health, and out-of-pocket (private) health expenditure by citizens were all associated with children's oral health. The structural determinants accounted for between 5% and 21% of the variance in children's oral health quality-of-life scores. These findings bring attention to the upstream or structural determinants as an understudied area but one that could reap huge rewards for public health dentistry research and the oral health inequalities policy agenda.

Microscopic Evolution of Laboratory Volcanic Hybrid Earthquakes.

Characterizing the interaction between fluids and microscopic defects is one of the long-standing challenges in understanding a broad range of cracking processes, in part because they are so difficult to study experimentally. We address this issue by reexamining records of emitted acoustic phonon events during rock mechanics experiments under wet and dry conditions. The frequency spectrum of these events provides direct information regarding the state of the system. Such events are typically subdivided into high frequency (HF) and low frequency (LF) events, whereas intermediate "Hybrid" events, have HF onsets followed by LF ringing. At a larger scale in volcanic terranes, hybrid events are used empirically to predict eruptions, but their ambiguous physical origin limits their diagnostic use. By studying acoustic phonon emissions from individual microcracking events we show that the onset of a secondary instability-related to the transition from HF to LF-occurs during the fast equilibration phase of the system, leading to sudden increase of fluid pressure in the process zone. As a result of this squeezing process, a secondary instability akin to the LF event occurs. This mechanism is consistent with observations of hybrid earthquakes.

Psychometric assessment of the short-form Child Perceptions Questionnaire: an international collaborative study.

OBJECTIVE: To examine the factor structure and other psychometric characteristics of the most commonly used child oral-health-related quality-of-life (OHRQoL) measure (the 16-item short-form CPQ11-14 ) in a large number of children (N = 5804) from different settings and who had a range of caries experience and associated impacts. METHODS: Secondary data analyses used subnational epidemiological samples of 11- to 14-year-olds in Australia (N = 372), New Zealand (three samples: 352, 202, 429), Brunei (423), Cambodia (244), Hong Kong (542), Malaysia (439), Thailand (220, 325), England (88, 374), Germany (1055), Mexico (335) and Brazil (404). Confirmatory factor analysis (CFA) was used to examine the factor structure of the CPQ11-14 across the combined sample and within four regions (Australia/NZ, Asia, UK/Europe and Latin America). Item impact and internal reliability analysis were also conducted. RESULTS: Caries experience varied, with mean DMFT scores ranging from 0.5 in the Malaysian sample to 3.4 in one New Zealand sample. Even more variation was noted in the proportion reporting only fair or poor oral health; this was highest in the Cambodian and Mexican samples and lowest in the German sample and one New Zealand sample. One in 10 reported that their oral health had a marked impact on their life overall. The CFA across all samples revealed two factors with eigenvalues greater than 1. The first involved all items in the oral symptoms and functional limitations subscales; the second involved all emotional well-being and social well-being items. The first was designated the 'symptoms/function' subscale, and the second was designated the 'well-being' subscale. Cronbach's alpha scores were 0.72 and 0.84, respectively. The symptoms/function subscale contained more of the items with greater impact, with the item 'Food stuck in between your teeth' having greatest impact; in the well-being subscale, the 'Felt shy or embarrassed' item had the greatest impact. Repeating the analyses by world region gave similar findings. CONCLUSION: The CPQ11-14 performed well cross-sectionally in the largest analysis of the scale in the literature to date, with robust and mostly consistent psychometric characteristics, albeit with two underlying factors (rather than the originally hypothesized four-factor structure). It appears to be a sound, robust measure which should be useful for research, practice and policy.

Observation of the Kibble-Zurek Mechanism in Microscopic Acoustic Crackling Noises.

Characterizing the fast evolution of microstructural defects is key to understanding "crackling" phenomena during the deformation of solid materials. For example, it has been proposed using atomistic simulations of crack propagation in elastic materials that the formation of a nonlinear hyperelastic or plastic zone around moving crack tips controls crack velocity. To date, progress in understanding the physics of this critical zone has been limited due to the lack of data describing the complex physical processes that operate near microscopic crack tips. We show, by analyzing many acoustic emission events during rock deformation experiments, that the signature of this nonlinear zone maps directly to crackling noises. In particular, we characterize a weakening zone that forms near the moving crack tips using functional networks, and we determine the scaling law between the formation of damages (defects) and the traversal rate across the critical point of transition. Moreover, we show that the correlation length near the transition remains effectively frozen. This is the main underlying hypothesis behind the Kibble-Zurek mechanism (KZM) and the obtained power-law scaling verifies the main prediction of KZM.

Eyes wide open: reader and author responsibility in understanding the limits of peer review.

'Medical science can only flourish in a free society and dies under totalitarian repression.' (1) Peer review post-publication is relatively easy to define: when the world decides the importance of publication. Peer review pre-publication is what the scientific community frequently means when using the term 'peer review'. But what it is it? Few will agree on an exact definition; generally speaking, it refers to an independent, third party scrutiny of a manuscript by scientific experts (called peers) who advise on its suitability for publication. Peer review is expensive; although reviewers are unpaid, the cost in time is enormous and it is slow. There is often little agreement among reviewers about whether an article should be published and peer review can be a lottery. Often referred to as a quality assurance process, there are many examples of when peer review failed. Many will be aware of Woo-Suk Hwang's shocking stem cell research misconduct at Seoul National University. (2) Science famously published two breakthrough articles that were found subsequently to be completely fabricated and this happened in spite of peer review. Science is not unique in making this error. However, love it or hate it, peer review, for the present time at least, is here to stay. In this article, Philippa Benson, Managing Editor of Science Advances (the first open access journal of the American Association for the Advancement of Science), discusses the merits of peer review. Dr Benson has extensive experience in the publishing world and was Executive Director of PJB Consulting, a not-for-profit organisation supporting clients on issues related to converting to full electronic publishing workflows as well as challenges working with international authors and publishers. Her clients included the Public Library of Science journals, the American Society for Nutrition and the de Beaumont Foundation. She recently co-authored a book, What Editors Want: An Author's Guide to Scientific Journal Publishing (University of Chicago Press), which helps readers understand and navigate the publishing process in high impact science and technical journals. Her master's and doctorate degrees are from Carnegie Mellon University. JYOTI SHAH Commissioning Editor References 1. Eaton KK . Editorial: when is a peer review journal not a peer review journal? J Nutr Environ Med 1997 ; 7 : 139 - 144 . 2. van der Heyden MA , van de Ven T , Opthof T . Fraud and misconduct in science: the stem cell seduction . Neth Heart J 2009 ; 17 : 25 - 29 .

What is the value of orthodontic treatment?

Orthodontic treatment is as popular as ever. Orthodontists frequently have long lists of people wanting treatment and the cost to the NHS in England was £258m in 2010-2011 (approximately 10% of the NHS annual spend on dentistry). It is important that clinicians and healthcare commissioners constantly question the contribution of interventions towards improving the health of the population. In this article, the authors outline some of the evidence for and against the claims that people with a malocclusion are at a disadvantage compared with those without a malocclusion and that orthodontic treatment has significant health benefits. The authors would like to point out that this is not a comprehensive and systematic review of the entire scientific literature. Rather the evidence is presented in order to stimulate discussion and debate.

SWIFT: prospective 48-week study to evaluate efficacy and safety of switching to emtricitabine/tenofovir from lamivudine/abacavir in virologically suppressed HIV-1 infected patients on a boosted protease inhibitor containing antiretroviral regimen.

BACKGROUND: In the United States, emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) is a preferred nucleoside reverse transcriptase inhibitor (NRTI) backbone with lamivudine/abacavir (3TC/ABC) as a commonly used alternative. For patients infected with human immunodeficiency virus (HIV-1) virologically suppressed on a boosted protease inhibitor (PI) + 3TC/ABC regimen, the merits of switching to FTC/TDF as the NRTI backbone are unknown. METHODS: SWIFT was a prospective, randomized, open-label 48-week study to evaluate efficacy and safety of switching to FTC/TDF. Subjects receiving 3TC/ABC + PI + ritonavir (RTV) with HIV-1 RNA < 200 c/mL ≥3 months were randomized to continue 3TC/ABC or switch to FTC/TDF. The primary endpoint was time to loss of virologic response (TLOVR) with noninferiority measured by delta of 12%. Virologic failure (VF) was defined as confirmed rebound or the last HIV-1 RNA measurement on study drug ≥200 c/mL. RESULTS: In total, 311 subjects were treated in this study (155 to PI + RTV + FTC/TDF, 156 to PI + RTV + 3TC/ABC). Baseline characteristics were similar between the arms: 85% male, 28% black, median age, 46 years; and median CD4 532 cells/mm(3). By TLOVR through week 48, switching to FTC/TDF was noninferior compared to continued 3TC/ABC (86.4% vs 83.3%, treatment difference 3.0% (95% confidence interval, -5.1% to 11.2%). Fewer subjects on FTC/TDF experienced VF (3 vs 11; P = .034). FTC/TDF showed greater declines in fasting low-density lipoproteins (LDL), total cholesterol (TC), and triglycerides (TG) with significant declines in LDL and TC beginning at week 12 with no TC/HDL ratio change. Switching to FTC/TDF showed improved NCEP thresholds for TC and TG and improved 10-year Framingham TC calculated scores. Decreased estimated glomerular filtration rate [corrected] (eGFR) was observed in both arms with a larger decrease in the FTC/TDF arm. CONCLUSIONS: Switching to FTC/TDF from 3TC/ABC maintained virologic suppression, had fewer VFs, improved lipid parameters and Framingham scores but decreased eGFR. CLINICALTRIALS.GOV IDENTIFIER: NCT00724711.

Starting treatment according to guidelines evaluation: a multicentre audit of HIV patients in the UK.

The aim of this audit was to assess whether HIV patients are being started on antiretroviral therapy (ART) according to British and European guidelines. Data were collected from the Survey of Prevalent HIV Infections Diagnosed (SOPHID) return for 2010 at five major HIV management centres in the UK. Data from this 3873 patient cohort revealed 52 patients who should have been receiving ART according to the guidelines but were not. Of these, 23 patients elected not to start ART despite clinical advice to the contrary. Information required to assist in the decision for earlier ART initiation (CD4 count 350­500 cells/mL) was missing for some patients. Clinicians must pay attention to the regular assessment of patients with a CD4 count of 351­500 cells/mL so that all those who may benefit from earlier treatment are identified. Future research should investigate patient barriers to initiating therapy following recommendation by a clinician.

Percutaneous lumbar pedicle screw placement aided by computer-assisted fluoroscopy-based navigation: perioperative results of a prospective, comparative, multicenter study.

STUDY DESIGN: Institutional review board-approved, prospective, multicenter, comparative study. OBJECTIVE: To assess the accuracy and utility of a computer-assisted fluoroscopic navigation method for percutaneous placement of lumbar pedicle screws compared with conventional fluoroscopic placement. SUMMARY OF BACKGROUND DATA: Recent reports indicate that cortical breaches during percutaneous pedicle screw placement can exceed 15%. Computed tomography (CT)- and fluoroscopy-based navigation systems may facilitate increased placement accuracy with reduced radiation exposure and operative times. METHODS: Patients were alternately assigned to either the Guidance or Control group. The Guidance group underwent lumbar pedicle screw placement using the oblique visualization technique and computer-assisted fluoroscopic navigation. The Control group underwent lumbar pedicle screw placement per standard percutaneous technique aided by fluoroscopy alone. Baseline demographics, visual analog scale (VAS) pain scores, and American Spinal Injury Association scores were obtained preoperatively and in the immediate postoperative period. Fluoroscopy times and guidewire insertion times were recorded intraoperatively. All postoperative CT scans were reviewed by an independent spine surgeon to grade screw placement accuracy. RESULTS: Forty-two patients (210 screws) were assigned to the Guidance group and 34 patients (152 screws) were assigned to the Control group. Use of Guidance resulted in reduced average fluoroscopy usage per pedicle [6.6 sec (SD = 5.1) vs. 9.6 sec (SD 6.2), P < 0.001] and more expedient placement of guidewires per pedicle [3.65 min (SD = 2.31) vs. 4.43 min (SD = 2.56), P = 0.003]. The Guidance group experienced less than half of the breach rate of the Control group (3.0% vs. 7.2%, P = 0.055) and reduced breach magnitudes. None of the breaches resulted in a corresponding neurological deficit or required revision. All patient-reported outcomes were significantly improved after surgery and there were no significant differences in average postoperative VAS scores between treatment groups. CONCLUSION: Use of Guidance reduces fluoroscopy and insertion times with increased accuracy compared with conventional fluoroscopic methods of percutaneous pedicle screw insertion.

Mortality from asbestosis and mesothelioma in Britain by birth cohort.

BACKGROUND: Analysis of occupational mortality in England and Wales during 1991-2000 showed no decline in work-attributable deaths from asbestosis. AIMS: To explore why there was no decline in mortality from asbestosis despite stricter controls on asbestos exposure over recent decades. METHODS: Using data from registers of all deaths in Great Britain with mention of mesothelioma or asbestosis on the death certificate, we plotted death rates by 5 year age group within 5 year birth cohorts for(a) mesothelioma and (b) asbestosis without mention of mesothelioma. RESULTS: Analysis was based on a total of 33,751 deaths from mesothelioma and 5396 deaths from asbestosis. For both diseases, mortality showed a clear cohort effect; within birth cohorts, death rates increased progressively with age through to 85 years and older. However, highest mortality from mesothelioma was in men born during 1939-43, whereas, mortality from asbestosis peaked in men born during 1924-38. CONCLUSIONS: Our findings suggest that mortality, in Britain, from asbestosis has been determined mainly by cumulative exposure to asbestos before 45 years of age and that the effect of such exposure continues through to old age. That mortality from asbestosis peaked in earlier birth cohorts than mortality from mesothelioma may reflect a difference in exposure-response relationships for the two diseases. The discrepancy could be explained if risk of asbestosis increased more steeply than that of mesothelioma at higher levels of exposure to asbestos and if the highest prevalence of heavy exposure occurred in earlier birth cohorts than the highest prevalence of less intense exposures.

The effect of chewing gum on the impact, pain and breakages associated with fixed orthodontic appliances: a randomized clinical trial.

OBJECTIVES: To determine whether the use of chewing gum reduced the impact and pain of fixed orthodontic appliances. SETTING AND SAMPLE POPULATION: The Orthodontic Department of the Charles Clifford Dental Hospital, Sheffield, UK. Fifty-seven patients aged 18 years or younger and who were about to start fixed orthodontic appliance treatment. SUBJECTS AND METHODS: A randomized clinical trial with two parallel groups either allocated to receive chewing gum after placement of their appliance or who were asked not to chew gum. The patients completed a previously validated Impact of Fixed Appliances questionnaire at 24 h and 1 week following each visit up until the placement of the working archwire. A visual analogue scale (VAS) was used to assess the intensity of pain. Appliance breakages were recorded to the end of treatment. RESULTS: The difference between the median Total Impact Score of the two groups at 24 h was 16, which was significant (p = 0.031; Mann-Whitney U-test). The difference between the median VAS between the two groups at 24 h was 25 mm, which was significant (p = 0.038; Mann-Whitney U-test). There were no differences at 1 week. None of the risk ratios for appliance breakages were significant. CONCLUSION: Chewing gum significantly decreased both the impact and pain from the fixed appliances. There was no evidence that chewing gum increased the incidence of appliance breakages.

Bitter taster status predicts susceptibility to vection-induced motion sickness and nausea.

BACKGROUND: Sensitivity to bitter taste and susceptibility to nausea are both protective mechanisms that guard against toxin ingestion, and both these traits vary within and between populations. Thus, we postulated that they may have co-evolved, such that they are associated. METHODS: Bitter taster status was determined in 40 subjects (13 men, 27 women) by measuring the differential perceived taste intensity between salt and n-propylthiouracil using a labeled magnitude scale; susceptibility to vection-induced motion sickness and nausea was assessed using an optokinetic drum, a validated multi-symptom scoring scale, and electrogastrography. KEY RESULTS: Taster status distribution was 25% non-tasters (NT), 40% tasters (T), and 35% supertasters (ST). Gender had no impact on this distribution, but females had a higher mean maximum symptom score than males (12.4 ± 1.4 vs 7.3 ± 2.0). Non-tasters displayed a faster and larger increase in mean symptom scores, had a higher percentage of subjects with high maximum symptom scores, and had a higher mean maximum score than T or ST, (14.8 ± 2.6 vs 7.1 ± 1.8, vs 9.8 ± 2.0). Taster status did not affect the gastric myoelectric frequency response to vection. CONCLUSIONS & INFERENCES: Non-tasters are more susceptible to vection-induced motion sickness and nausea than T or ST, suggesting these two traits may have co-evolved in a reciprocal manner: in environments where the NT trait conferred an evolutionary advantage by enabling intake of fruits and vegetables containing bitter, yet beneficial, phytonutrients, increased nausea susceptibility may have arisen to maintain protection against ingested toxins.