192 research outputs found

    Biases in Long-term NO2 Averages Inferred from Satellite Observations Due to Cloud Selection Criteria

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    Retrievals of atmospheric trace gas column densities from space are compromised by the presence of clouds, requiring most studies to exclude observations with significant cloud fractions in the instrument's field of view. Using NO2 observations at three ground stations representing urban, suburban, and rural environments, and tropospheric vertical column densities measured by the Ozone Monitoring Instrument (OMI) over each site, we show that the observations from space represent monthly averaged ground-level pollutant conditions well (R=0.86) under relatively cloud-free conditions. However, by analyzing the ground-level data and applying the OMI cloud fraction as a filter, we show there is a significant bias in long-term averaged NO2 as a result of removing the data during cloudy conditions. For the ground-based sites considered in this study, excluding observations on days when OMI-derived cloud fractions were greater than 0.2 causes 12:00-14:00 mean summer mixing ratios to be underestimated by 12%+/-6%, 20%+/-7%, and 40%+/-10% on average (+/-1 standard deviation) at the urban, suburban, and rural sites respectively. This bias was investigated in particular at the rural site, a region where pollutant transport is the main source of NO2, and where longterm observations of NOy were also available. Evidence of changing photochemical conditions and a correlation between clear skies and the transport of cleaner air masses play key roles in explaining the bias. The magnitude of a bias is expected to vary from site to site depending on meteorology and proximity to NOx sources, and decreases when longer averaging times of ground station data (e.g. 24-h) are used for the comparison

    Risk factors for bleeding complications after nephrologist-performed native renal biopsy

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    Background: Bleeding is a recognized complication of native percutaneous renal biopsy. This study aimed to describe the incidence of major bleeding after biopsy in a single centre over a 15-year period and examine factors associated with major bleeding. Methods: We identified consecutive adult patients undergoing ultrasound-guided native renal biopsy in the Glasgow Renal and Transplant Unit from 2000 to 2014. From the electronic patient record, we collected data pertaining to biopsy indication, pre- and post-biopsy laboratory measurements, prescribed medication and diagnosis. Aspirin was routinely continued. We defined major bleeding post-biopsy as the need for blood transfusion, surgical or radiological intervention or death. Binary logistic regression analysis was used to assess factors associated with increased risk of major bleeding. Results: There were 2563 patients who underwent native renal biopsy (1499 elective, 1064 emergency). The average age of patients was 57 (SD 17) years and 57.4% were male. Overall, the rate of major bleeding was 2.2%. In all, 46 patients required transfusion (1.8%), 9 patients underwent embolization (0.4%), no patient required nephrectomy and 1 patient died as a result of a significant late retroperitoneal bleed. Major bleeding was more common in those undergoing emergency compared with elective renal biopsy (3.4 versus 1.1%; P < 0.001). Aspirin was being taken at the time of biopsy in 327 of 1509 patients, with no significant increase in the risk of major bleeding (P = 0.93). Body mass index (BMI) data were available for 546 patients, with no increased risk of major bleeding in 207 patients classified as obese (BMI >30). Conclusions: The risk of major bleeding following native renal biopsy in the modern era is low. Complications are more common when biopsy is conducted as an emergency, which has implications for obtaining informed consent. Our data support the strategy of not stopping aspirin before renal biopsy

    The utility of anti-Müllerian hormone in women with chronic kidney disease, on haemodialysis and after kidney transplantation

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    Women with renal disease have menstrual and gonadal dysfunction manifesting as hormonal imbalance. Anti-Müllerian hormone (AMH) is a potential measure of ovarian reserve. We examined circulating AMH concentrations in young women with renal failure, determined associations with clinical characteristics, and compared AMH with age-matched healthy individuals. AMH was measured in 77 women: 26 had chronic kidney disease (CKD), 26 were on haemodialysis (HD), and 25 had a kidney transplant. Random AMH levels were highest in women on HD [HD 2.9 (1.1–5.2), CKD 1.6 (0.7–2.2), transplant 1.5 (1.0–4.2) ng/ml]. On multiple linear regression, AMH was 53% higher [95% CI 0.20–0.98, P = 0.002] in women on HD and decreased by 20% per 5-year increase in age (P < 0.001). AMH was 43% lower in women with renal failure compared with 600 age-matched controls [1.7 (0.9–3.8) versus 3.0 (1.9–5.0) ng/ml, P < 0.001]; however, we found no difference in AMH between those on HD and healthy individuals [2.9 (1.1–5.2) versus 3.0 (1.9–5.0) ng/ml]. AMH may be a useful biomarker in female renal patients with non-dialysis dependent renal disease pursuing pregnancy. In contrast, AMH levels are higher in HD but unlikely to reflect ovarian reserve

    Consent to discuss participation in research: A pilot study

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    Background. Equitable access to research studies needs to be increased for all patients. There is debate about which is the best approach to use to discuss participation in research in real-world clinical settings. Objective. We aimed to determine the feasibility of asking all clinical staff within one hospital Trust (an organisation that provides secondary health services within the English and Welsh National Health Service) to use a newly created form on the Trust’s electronic patient records system, as a means of asking patients to consent to discuss participation in research (the opt-in approach). We also aimed to collect feedback from patients and clinicians about their views of the opt-in approach. Methods. Four pilot sites were selected in the Trust: two memory clinics, an adult mental health team and an acute adult ward. Data were collected in three phases: (1) for 6 months, pilot site staff were asked to complete a consent to discuss participation in research form with patients; (2) staff feedback on the form was collected through an online survey; and (3) patient feedback was collected through focus groups. Findings. Of 1779 patients attending services during the pilot period, 197 (11%) had a form completed by staff and 143 (8%) opted-in to finding out about research. Staff cited limited time, low priority and poor user experience of the electronic patient records system as reasons for low uptake of the form. Patients generally approved of the approach but offered suggestions for improvement. Conclusions. There were mixed results for adopting an opt-in approach; uptake was very low, limiting its value as an effective strategy for improving access to research. Clinical implications. Alternative strategies to the opt-in approach, such as transparent opt out approaches, warrant consideration to maximise access to research within routine clinical care

    Obesity is not associated with progression to end stage renal disease in patients with biopsy-proven glomerular diseases

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    Background: Body mass index (BMI) is associated with renal disease progression in unspecified CKD. The relationship between BMI and primary glomerular disease (GN) may be more complex. We aimed to evaluate the association between BMI and renal disease progression in patients with primary glomerular disease (GN). Methods: This was a single-centre retrospective cohort study performed in adult patients with biopsy-proven primary GN (excluding minimal change disease) from January 2000 to December 2015, with follow-up data until June 2017. BMI at time of biopsy was categorised as ≤25 kg/m2, > 25 to ≤30 kg/m2 and > 30 kg/m2. We used univariate and multivariate survival analyses to evaluate factors associated with progression to a composite endpoint of stage 5 CKD or renal replacement therapy (Major Adverse Renal Event - MARE) censoring for competing risk of death using Fine and Gray subdistribution hazards model. Results: We included 560 patients with biopsy-proven primary GN and available BMI data: 66.1% were male with median age 54.8 (IQR 41.1–66.2) years and BMI 28.2 (IQR 24.9–32.1) kg/m2. Those with BMI 25-30 kg/m2 (n = 210) and with BMI > 30 kg/m2 (n = 207) were older (p = 0.007) with higher systolic and diastolic blood pressures (p = 0.02 and 0.004 respectively) than those with BMI < 25 kg/m2 (n = 132). There was a greater proportion of focal segmental glomerulosclerosis in those with higher BMI (3.9% in BMI < 25 kg/m2, 7.9% in BMI 25–30 kg/m2 and 10.7% in BMI > 30 kg/m2 of biopsies (p = 0.01)), but similar proportions of other GN diagnoses across BMI groups. Baseline eGFR (p = 0.40) and uPCR (p = 0.17) were similar across BMI groups. There was no interaction between BMI and time to MARE (log-rank p = 0.98) or death (log-rank p = 0.42). Censoring for competing risk of death, factors associated with progression to MARE were: younger age, lower baseline eGFR and higher uPCR, but not BMI (SHR 0.99, 95%CI 0.97–1.01, p = 0.31) nor blood pressure or GN diagnosis. Conclusion: BMI was not associated with progression to MARE in this patient cohort with primary GN. Efforts should be directed to managing other known risk factors for CKD progression

    Fusarium head blight of barley : resistance evaluation and identification of resistance mechanisms

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    xvii, 196 leaves : ill. ; 29 cm.An evaluation of nineteen barley lines using three artificial inoculation methods concluded that spray inoculation was the most reproducible method and provided the greatest discrimination of resistance. Six of the nineteen barley lines were used for proteomic studies to identify defense responses following F. graminearum infection. All lines responded by inducing an oxidative burst and pathogenesis-related proteins. Differences in response magnitude and the proteins activated could be attributed to varying levels of FHB resistance amongst the barley lines. RNA microarray profiling and iTRAQ technology were used to study the interaction between two barley lines under five different treatments testing the effect of the fungus, trichothecene, and their interaction. Resistance was differentiated by the early induction of defense-related genes and the activation of the JA and ethylene defense pathways in Chevron, compared to the induction of a less efficient defense pathway in Stander; observed intra- and inter-cultivar differential responses are discussed

    Wellbeing of breastfeeding women in Australia and New Zealand during the covid‐19 pandemic: A cross‐sectional study

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    During the COVID‐19 pandemic, breastfeeding women have experienced restricted access to support, placing them at increased risk of mental health concerns and limited breastfeeding assistance. This study investigated the effect of the pandemic on feeding choices and maternal well-being amongst breastfeeding mothers living in Australian and New Zealand. We conducted a cross-sectional online survey that examined feeding methods, maternal mental wellbeing, worries, challenges, and positive experiences during the pandemic. Most women were exclusively breastfeeding (82%). Partial breastfeeding was associated with perceived low milk supply and longer pregnancy duration during the pandemic. Reduced mental health and wellbeing was associated with lower levels of family functioning, increased perceived stress, and perinatal anxiety. Longer pregnancy duration during the pandemic was associated with lower mental health wellbeing scores, while higher perceived stress scores were reported for regions with higher COVID‐19 infection rates and women with perceived low milk supply. Women reported that the pandemic resulted in less pressure and more time for family bonding, while worries about the pandemic, family health, and parenting challenges were also cited. Mental health concerns of breastfeeding women appear to be exacerbated by COVID‐19, highlighting a critical need for access to mental health and broader family support during the pandemic

    Longitudinal changes in wellbeing amongst breastfeeding women in Australia and New Zealand during the COVID-19 pandemic

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    The COVID-19 pandemic has impacted new mothers’ wellbeing and breastfeeding experience. Women have experienced changes in birth and postnatal care and restricted access to their support network. It is unclear how these impacts may have changed over time with shifting rates of infection and policies restricting movement and access to services in Australia and New Zealand. This study investigated the longitudinal effect of the COVID-19 pandemic on breastfeeding and maternal wellbeing in Australia and New Zealand. Mothers (n = 246) completed an online survey every 4 weeks for 6 months that examined feeding methods, maternal mental wellbeing, worries, challenges, and positive experiences during the pandemic. Mothers maintained high full breastfeeding rates at 4 months (81%) which decreased to 37% at 6 months. Perceived low milk supply contributed to the earlier cessation of full breastfeeding. Poor infant sleep was associated with stress, perinatal anxiety, mental wellbeing, and breastfeeding status. Although mothers initially reported that lockdowns helped with family bonding and less pressure, prolonged lockdowns appeared to have adverse effects on access to social networks and extended family support. Conclusion: The results highlight the changing dynamic of the pandemic and the need for adaptable perinatal services which allow mothers access to in-person services and their support network even in lockdowns. Similarly, access to continuous education and clinical care remains critical for women experiencing concerns about their milk supply, infant sleep, and their own wellbeing. What is Known: The COVID-19 pandemic and lockdown restrictions have significantly affected perinatal mental health, disrupted maternal services, and subsequent breastfeeding. What is New: In Australia and New Zealand, breastfeeding women experienced challenges to their mental wellbeing, sleep, and breastfeeding, which was likely exacerbated over time by the pandemic. Lockdowns, while initially beneficial for some families, became detrimental to maternal support and wellbeing
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