Expanded quantum vortex liquid regimes in the electron nematic superconductors FeSe1-xSx and FeSe1-xTex.

The quantum vortex liquid (QVL) is an intriguing state of type-II superconductors in which intense quantum fluctuations of the superconducting (SC) order parameter destroy the Abrikosov lattice even at very low temperatures. Such a state has only rarely been observed, however, and remains poorly understood. One of the key questions is the precise origin of such intense quantum fluctuations and the role of nearby non-SC phases or quantum critical points in amplifying these effects. Here we report a high-field magnetotransport study of FeSe1-xSx and FeSe1-xTex which show a broad QVL regime both within and beyond their respective electron nematic phases. A clear correlation is found between the extent of the QVL and the strength of the superconductivity. This comparative study enables us to identify the essential elements that promote the QVL regime in unconventional superconductors and to demonstrate that the QVL regime itself is most extended wherever superconductivity is weakest.

Charge density waves and Fermi surface reconstruction in the clean overdoped cuprate superconductor Tl2Ba2CuO6+δ.

Hall effect and quantum oscillation measurements on high temperature cuprate superconductors show that underdoped compositions have small Fermi surface pockets whereas when heavily overdoped, a single much larger pocket is found. The origin of this change in electronic structure has been unclear, but may be related to the high temperature superconductivity. Here we show that the clean overdoped single-layer cuprate Tl2Ba2CuO6+δ (Tl2201) displays CDW order with a remarkably long correlation length ξ ≈ 200 Å which disappears above a hole doping of pCDW ≈ 0.265. We show that the evolution of the electronic properties of Tl2201 as the doping is lowered may be explained by a Fermi surface reconstruction which accompanies the emergence of the CDW below pCDW. Our results demonstrate importance of CDW correlations in understanding the electronic properties of overdoped cuprates.

Incoherent transport across the strange-metal regime of overdoped cuprates.

Strange metals possess highly unconventional electrical properties, such as a linear-in-temperature resistivity1-6, an inverse Hall angle that varies as temperature squared7-9 and a linear-in-field magnetoresistance10-13. Identifying the origin of these collective anomalies has proved fundamentally challenging, even in materials such as the hole-doped cuprates that possess a simple bandstructure. The prevailing consensus is that strange metallicity in the cuprates is tied to a quantum critical point at a doping p* inside the superconducting dome14,15. Here we study the high-field in-plane magnetoresistance of two superconducting cuprate families at doping levels beyond p*. At all dopings, the magnetoresistance exhibits quadrature scaling and becomes linear at high values of the ratio of the field and the temperature, indicating that the strange-metal regime extends well beyond p*. Moreover, the magnitude of the magnetoresistance is found to be much larger than predicted by conventional theory and is insensitive to both impurity scattering and magnetic field orientation. These observations, coupled with analysis of the zero-field and Hall resistivities, suggest that despite having a single band, the cuprate strange-metal region hosts two charge sectors, one containing coherent quasiparticles, the other scale-invariant 'Planckian' dissipators.

Investigation of the potential of buffalo and couch grasses to grow on AFIs and for removal of nutrients from paper mill wastewater.

The potential growth of buffalo grass (Stenotaphrum secundatum) and couch grass (Cynodon dactylon) on artificial floating islands (AFIs) and their ability to remove total nitrogen (TN) and total phosphorus (TP) from a simulated paper mill wastewater was studied. This was done to assess the potential of AFIs for removal of nutrients from aerated stabilization basins (ASBs) that had occasional growth of blue-green algae (BGA) to bloom levels. Small scale AFIs were prepared using polyethylene foam and planted with the grasses in 30 L of tested water. Trials were conducted in a plastic covered greenhouse over a three-month period where temperatures ranged from 15 to 44 °C. The results showed that both buffalo and couch grasses can adapt to planting in AFIs showing increases of 125% and 148% in wet weight, respectively. Nutrient uptake by buffalo grass and couch grass were found to be similar. Percentage uptakes of TP and TN from the synthetic water by the buffalo grass were 82% and 47%, whereas by couch grass, uptakes were 83% and 45%, respectively.

Electrical resistivity across a nematic quantum critical point.

Correlated electron systems are highly susceptible to various forms of electronic order. By tuning the transition temperature towards absolute zero, striking deviations from conventional metallic (Fermi-liquid) behaviour can be realized. Evidence for electronic nematicity, a correlated electronic state with broken rotational symmetry, has been reported in a host of metallic systems1-5 that exhibit this so-called quantum critical behaviour. In all cases, however, the nematicity is found to be intertwined with other forms of order, such as antiferromagnetism5-7 or charge-density-wave order8, that might themselves be responsible for the observed behaviour. The iron chalcogenide FeSe1-xSx is unique in this respect because its nematic order appears to exist in isolation9-11, although until now, the impact of nematicity on the electronic ground state has been obscured by superconductivity. Here we use high magnetic fields to destroy the superconducting state in FeSe1-xSx and follow the evolution of the electrical resistivity across the nematic quantum critical point. Classic signatures of quantum criticality are revealed: an enhancement in the coefficient of the T2 resistivity (due to electron-electron scattering) on approaching the critical point and, at the critical point itself, a strictly T-linear resistivity that extends over a decade in temperature T. In addition to revealing the phenomenon of nematic quantum criticality, the observation of T-linear resistivity at a nematic critical point also raises the question of whether strong nematic fluctuations play a part in the transport properties of other 'strange metals', in which T-linear resistivity is observed over an extended regime in their respective phase diagrams.

Investigation and treatment of premature ovarian insufficiency: A multi-disciplinary review of practice.

Objectives: To assess compliance with the European Society for Human Reproduction and Embryology (ESHRE) guidelines on the investigation and management of women with premature ovarian insufficiency at the Leeds Teaching Hospitals NHS Trust (LTHT) and to determine whether this varies depending on the clinical setting in which the women present. Study design: A retrospective review of all females diagnosed with premature ovarian insufficiency between 1 July 2016 and 30 June 2017, presenting to one of the following clinics: reproductive medicine, specialist menopause, general gynaecology, oncology long-term follow-up, general endocrinology or paediatric endocrinology. Main outcome measures: Proportion of patients who had the necessary investigations performed and relevant treatment options discussed. Results: 103 women were included in the study. Overall, 40.6% had a karyotype. Screening for the Fragile-X pre-mutation, thyroid peroxidase and 21-hydroxylase antibodies occurred in 7.4%, 11.1% and 13.6% of women, respectively. Only 35.9% had their bone mineral density measured. There was significant variation in the performance of a karyotype (p < 0.001) and thyroid peroxidase antibodies (p < 0.01) between the different clinical settings. Overall, lifestyle advice was offered to 30.1%. Estrogen replacement, contraception, fertility options and bone protection were discussed with 76.0%, 38.4%, 59.0% and 75.0%, respectively. Psychological support was offered to 25.2%. There was significant variation for all apart from contraception. Conclusion: The investigation and treatment of women with premature ovarian insufficiency at the LTHT is not consistent with the ESHRE guidelines and requires improvement. Furthermore, there is significant variation in management depending on the department to which the patient initially presents.

Systematic review: chronic obstructive pulmonary disease and work-related outcomes.

Background: Several studies have assessed the impact of chronic obstructive pulmonary disease (COPD) on work ability and work productivity; however, this relationship is poorly understood. Aims: To undertake a systematic review to assess the effects of COPD on employment, absenteeism and presenteeism. Methods: A comprehensive search using CINAHL, Embase, MEDLINE and the Cochrane Library was conducted to include epidemiological studies from 1937 to August 2017. One reviewer screened all citations. Shortlisted full-text articles were independently assessed by a second reviewer. Data were extracted by one reviewer with a random sample of papers (45%) checked by a second reviewer. Results: Forty-four studies were included; the majority of evidence was from cross-sectional studies, and some cohort studies. COPD patients had lower employment rates than those without COPD. Among those in work, most studies showed patients with COPD took more time off work than those without and reported poorer work performance (presenteeism), although evidence for this association was weaker. The influence of disease severity on these outcomes was unclear; however, it appeared that increasing severity of airflow obstruction was associated with reduced likelihood of being employed. A number of methodological limitations were found among the evidence, including the lack of adjustment for important confounders. Conclusions: Future studies are required which assess the impact of COPD on presenteeism using validated presenteeism instruments and consistent reporting methods. Robust studies are now needed to identify modifiable factors associated with these poorer working outcomes to inform future interventions aimed at improving work productivity among those with COPD.

Disease tolerance: concept and mechanisms.

Two distinct defense strategies provide a host with survival to infectious diseases: resistance and tolerance. Resistance is dependent on the ability of the host to kill pathogens. Tolerance promotes host health while having a neutral to positive impact of pathogen fitness. Immune responses are almost inevitably defined in terms of pathogen resistance. Recent evidence has shown, however, that several effects attributed to activation of innate and adaptive immune mechanisms, cannot be readily explained with the paradigm of immunity as effectors of microbial destruction. This review focuses on integrating the concept of disease tolerance into recent studies of immune system function related to the regulation and resolution of tissue damage, T cell exhaustion, and tolerance to innocuous antigen.

Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal.

Household Air Pollution (HAP) from biomass cooking fuels is a major cause of morbidity and mortality in low-income settings worldwide. In Nepal the use of open stoves with solid biomass fuels is the primary method of domestic cooking. To assess patterns of domestic air pollution we performed continuous measurement of carbon monoxide (CO) and particulate Matter (PM2.5) in 12 biomass fuel households in Janakpur, Nepal. We measured kitchen PM2.5 and CO concentrations at one-minute intervals for an approximately 48-h period using the TSI DustTrak II 8530/SidePak AM510 (TSI Inc, St. Paul MN, USA) or EL-USB-CO data logger (Lascar Electronics, Erie PA, USA) respectively. We also obtained information regarding fuel, stove and kitchen characteristics and cooking activity patterns. Household cooking was performed in two daily sessions (median total duration 4 h) with diurnal variability in pollutant concentrations reflecting morning and evening cooking sessions and peak concentrations associated with fire-lighting. We observed a strong linear relationship between PM2.5 measurements obtained by co-located photometric and gravimetric monitoring devices, providing local calibration factors of 4.9 (DustTrak) and 2.7 (SidePak). Overall 48-h average CO and PM2.5 concentrations were 5.4 (SD 4.3) ppm (12 households) and 417.6 (SD 686.4) µg/m3 (8 households), respectively, with higher average concentrations associated with cooking and heating activities. Overall average PM2.5 concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5 and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5 exposure assessment in this setting. Domestic indoor air quality levels associated with biomass fuel combustion in this region exceed WHO Indoor Air Quality standards and are in the hazardous range for human health.

A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years.

OBJECTIVES: Childhood asthma is a complex condition where many environmental factors are implicated in causation. The aim of this study was to complete a systematic review of the literature describing associations between environmental exposures and the development of asthma in young children. SETTING: A systematic review of the literature up to November 2013 was conducted using key words agreed by the research team. Abstracts were screened and potentially eligible papers reviewed. Papers describing associations between exposures and exacerbation of pre-existing asthma were not included. Papers were placed into the following predefined categories: secondhand smoke (SHS), inhaled chemicals, damp housing/mould, inhaled allergens, air pollution, domestic combustion, dietary exposures, respiratory virus infection and medications. PARTICIPANTS: Children aged up to 9 years. PRIMARY OUTCOMES: Diagnosed asthma and wheeze. RESULTS: 14,691 abstracts were identified, 207 papers reviewed and 135 included in the present review of which 15 were systematic reviews, 6 were meta-analyses and 14 were intervention studies. There was consistent evidence linking exposures to SHS, inhaled chemicals, mould, ambient air pollutants, some deficiencies in maternal diet and respiratory viruses to an increased risk for asthma (OR typically increased by 1.5-2.0). There was less consistent evidence linking exposures to pets, breast feeding and infant dietary exposures to asthma risk, and although there were consistent associations between exposures to antibiotics and paracetamol in early life, these associations might reflect reverse causation. There was good evidence that exposures to house dust mites (in isolation) was not associated with asthma risk. Evidence from observational and intervention studies suggest that interactions between exposures were important to asthma causation, where the effect size was typically 1.5-3.0. CONCLUSIONS: There are many publications reporting associations between environmental exposures and modest changes in risk for asthma in young children, and this review highlights the complex interactions between exposures that further increase risk.

Voice disorders in Nigerian primary school teachers.

BACKGROUND: The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. School teachers routinely use their voices intensively at work and are therefore at a higher risk of dysphonia. AIMS: To determine the prevalence of voice disorders among primary school teachers in Lagos, Nigeria, and to explore associated risk factors. METHODS: Teaching and non-teaching staff from 19 public and private primary schools completed a self-administered questionnaire to obtain information on personal lifestyles, work experience and environment, and voice disorder symptoms. Dysphonia was defined as the presence of at least one of the following: hoarseness, repetitive throat clearing, tired voice or straining to speak. RESULTS: A total of 341 teaching and 155 non-teaching staff participated. The prevalence of dysphonia in teachers was 42% compared with 18% in non-teaching staff. A significantly higher proportion of the teachers reported that voice symptoms had affected their ability to communicate effectively. School type (public/private) did not predict the presence of dysphonia. Statistically significant associations were found for regular caffeinated drink intake (odds ratio [OR] = 3.07; 95% confidence interval [CI]: 1.51-6.62), frequent upper respiratory tract infection (OR = 3.60; 95% CI: 1.39-9.33) and raised voice while teaching (OR = 10.1; 95% CI: 5.07-20.2). CONCLUSIONS: Nigerian primary school teachers were at risk for dysphonia. Important environment and personal factors were upper respiratory infection, the need to frequently raise the voice when teaching and regular intake of caffeinated drinks. Dysphonia was not associated with age or years of teaching.

Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal.

The exposure of children to air pollution in low resource settings is believed to be high because of the common use of biomass fuels for cooking. We used microenvironment sampling to estimate the respirable fraction of air pollution (particles with median diameter less than 4 µm) to which 7-9 year old children in southern Nepal were exposed. Sampling was conducted for a total 2649 h in 55 households, 8 schools and 8 outdoor locations of rural Dhanusha. We conducted gravimetric and photometric sampling in a subsample of the children in our study in the locations in which they usually resided (bedroom/living room, kitchen, veranda, in school and outdoors), repeated three times over one year. Using time activity information, a 24-hour time weighted average was modeled for all the children in the study. Approximately two-thirds of homes used biomass fuels, with the remainder mostly using gas. The exposure of children to air pollution was very high. The 24-hour time weighted average over the whole year was 168 µg/m(3). The non-kitchen related samples tended to show approximately double the concentration in winter than spring/autumn, and four times that of the monsoon season. There was no difference between the exposure of boys and girls. Air pollution in rural households was much higher than the World Health Organization and the National Ambient Air Quality Standards for Nepal recommendations for particulate exposure.

Employment in adults with cystic fibrosis.

BACKGROUND: Chronic ill-health may significantly impact on an individual's ability to work. This not only relates to disease severity but also to psychosocial factors such as illness perception and coping strategies. AIMS: To explore the factors associated with employment status in adults with cystic fibrosis (CF). METHODS: Subjects recruited from adult CF clinics in Aberdeen, Birmingham and Newcastle completed questionnaires assessing health-related quality of life (HRQoL), workplace productivity (presenteeism) and employment. Clinical data indicative of disease severity were also recorded. RESULTS: A total of 254 subjects were recruited, 41 from Aberdeen, 63 from Birmingham and 150 from Newcastle. Sixty-five per cent of subjects were in employment or education. If employed/self-employed, median hours worked was 37.3h/week. Forty per cent reported stopping a job due to CF; 47% felt CF had affected career choice and 24% changed duties because of CF. Ten per cent had taken a pay cut and 23% reported workplace discrimination due to CF. Multivariate modelling demonstrated that employment status was independently associated with educational attainment, centre and the HRQoL domains of role and health perception and is independent of clinical parameters of disease severity. CONCLUSIONS: Adults with CF reported that CF impacted on their ability to work. Employment appeared to be most strongly associated with educational attainment, locality and HRQoL domains and not clinical parameters of severity. Specific guidance is needed for both adults with CF and potential employers, with appropriate targeted interventions aimed at improving health perceptions and coping strategies.

Oxidative potential of smoke from burning wood and mixed biomass fuels.

More than half the world's population still rely on burning biomass fuels to heat and light their homes and cook food. Household air pollution, a common component of which is inhalable particulate matter (PM), emitted from biomass burning is associated with increased vulnerability to respiratory infection and an enhanced risk of developing chronic obstructive pulmonary disease. In the light of an emerging hypothesis linking chronic PM exposure during childhood and increased vulnerability to respiratory diseases in adulthood, in a chain of events involving oxidative stress, reduced immunity and subsequent infection, the aim of this study was to characterise the oxidative potential (OP) of PM collected during the burning of wood and mixed biomass, whilst cooking food in the Kathmandu Valley, Nepal. Our assessments were based on the capacity of the particles to deplete the physiologically relevant antioxidants from a validated, synthetic respiratory tract lining fluid (RTLF). Incubation of mixed biomass and wood smoke particles suspensions with the synthetic RTLF for 4 h resulted in a mean loss of ascorbate of 64.76 ± 16.83% and 83.37 ± 14.12% at 50 µg/ml, respectively. Reduced glutathione was depleted by 49.29 ± 15.22% in mixed biomass and 65.33 ± 13.01% in wood smoke particles under the same conditions. Co-incubation with the transition metal chelator diethylenetriaminepentaacetate did not inhibit the rate of ascorbate oxidation, indicating a negligible contribution by redox-active metals in these samples. The capacity of biomass smoke particles to elicit oxidative stress certainly has the potential to contribute towards negative health impacts associated with traditional domestic fuels in the developing world.

Low back pain among textile workers: a cross-sectional study.

BACKGROUND: Low back pain (LBP) is one of the most prevalent occupational health problems in industrialized countries. Little is known about the epidemiology of LBP in developing countries. AIMS: To determine the prevalence of LBP among Nepalese textile workers and to investigate the influence of exposure to mechanical and other factors on LBP reporting. METHODS: Interviewers completed questionnaires with study subjects, and work-related mechanical exposures were measured by self-completed questionnaires. Associations of LBP with mechanical factors and somatic symptoms were determined by logistic regression and reported as odds ratios (ORs) with 95% confidence intervals (CI). RESULTS: Nine hundred and thirty-eight workers took part, a participation rate of 92%. The 1 month period prevalence of LBP was 35% (n = 324), being higher in females than males (45% versus 28%; P < 0.001). Several work-related mechanical factors were associated with increased odds of reporting LBP: lifting heavy weights with one hand (OR 1.7; 95% CI 1.1-2.8), pushing weights (OR 1.6; 95% CI 1.2-2.3 and pulling weights (OR 1.6; 95% CI 1.1-2.1). No association was found with working posture. Strong associations were found for reporting one (OR 2.4; 95% CI 1.7-3.4) or two somatic symptoms (OR 2.7; 95% CI 1.4-5.1). On multivariable analysis, reporting of somatic symptoms (OR 2.8; 95% CI 1.5-5.4), female gender (OR 2.2; 95% CI 1.5-3.1) and increasing age were significantly associated with increased risk of reporting LBP (OR 1.7; 95% CI 1.2-2.5), but no associations were found with mechanical factors. CONCLUSIONS: This study suggests that mechanical load may not be the leading cause of LBP and adds to evidence that psychological factors play an important role in LBP in non-industrialized countries.

Thunderstorm asthma: an overview of the evidence base and implications for public health advice.

Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following the occurrence of thunderstorms in the local vicinity. The roles of accompanying meteorological features and aeroallergens, such as pollen grains and fungal spores, have been studied in an effort to explain why thunderstorm asthma does not accompany all thunderstorms. Despite published evidence being limited and highly variable in quality due to thunderstorm asthma being a rare event, this article reviews this evidence in relation to the role of aeroallergens, meteorological features and the impact of thunderstorm asthma on health services. This review has found that several thunderstorm asthma events have had significant impacts on individuals' health and health services with a range of different aeroallergens identified. This review also makes recommendations for future public health advice relating to thunderstorm asthma on the basis of this identified evidence.

Audit of the recording of occupational asthma in primary care.

BACKGROUND: Occupational asthma (OA) remains common; 1 in 10 cases of adult-onset asthma is due to work. Health outcomes are better with early diagnosis, but there is considerable delay, largely due to lack of enquiry about work effect in primary care. National guidelines (2008) recommend asking two screening questions, which together have a high sensitivity in identifying OA. AIMS: To audit how working-age asthmatics are currently screened for OA in a local primary care population. METHODS: An audit of the electronic patient records of working-age asthmatics, from four Birmingham primary care practices was undertaken. Practice-level data (list size, gender, prevalence of asthma and OA and socio-economic status) and patient-level data (gender, age, onset, occupation and work-effect enquiry and lung function) were collected. RESULTS: The total practice population was 27,295 of which 17,564 (64%) were of working age. The audit sample was 396 of whom 49% were male. The prevalence of asthma in working-age adults was 12% (8-15%) and the prevalence of OA in working-age asthmatics was 0.3% (0-0.8%). Occupation was recorded in only 55/396 (14%) cases with very few (2) documented within the asthma-review template. Occupation was only recorded in 13/55 adult-onset asthmatics in high-risk occupations. Of 396, 9 (2%) had any work-effect enquiry and 4 patients had work-effect enquiry at diagnosis in those with traceable notes (n = 117). CONCLUSIONS: The prevalence of OA was low, suggesting under-diagnosis plus under-reporting in primary care. Occupation and work-effect enquiry is lacking despite guidelines for identifying OA. Existing electronic templates for recording asthma review could be modified to include these elements.