2,690 research outputs found

    Positronium collisions with rare-gas atoms

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    We calculate elastic scattering of positronium (Ps) by the Xe atom using the recently developed pseudopotential method [I. I. Fabrikant and G. F. Gribakin, Phys. Rev. A 90, 052717 (2014)] and review general features of Ps scattering from heavier rare-gas atoms: Ar, Kr, and Xe. The total scattering cross section is dominated by two contributions: elastic scattering and Ps ionization (breakup). To calculate the Ps ionization cross sections we use the binary-encounter method for Ps collisions with an atomic target. Our results for the ionization cross section agree well with previous calculations carried out in the impulse approximation. Our total Ps-Xe cross section, when plotted as a function of the projectile velocity, exhibits similarity with the electron-Xe cross section for the collision velocities higher than 0.8 a.u., and agrees very well with the measurements at Ps velocities above 0.5 a.u.Comment: 7 pages, 7 figures, submitted to J. Phys.

    Cadherin-5: a biomarker for metastatic breast cancer with optimum efficacy in oestrogen receptor-positive breast cancers with vascular invasion

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    Background: A glycoproteomic study has previously shown cadherin-5 (CDH5) to be a serological marker of metastatic breast cancer when both protein levels and glycosylation status were assessed. In this study we aimed to further validate the utility of CDH5 as a biomarker for breast cancer progression. Methods: A nested caseā€“control study of serum samples from breast cancer patients, of which n=52 had developed a distant metastatic recurrence within 5 years post-diagnosis and n=60 had remained recurrence-free. ELISAs were used to quantify patient serum CDH5 levels and assess glycosylation by Helix pomatia agglutinin (HPA) binding. Clinicopathological, treatment and lifestyle factors associated with metastasis and elevated biomarker levels were identified. Results: Elevated CDH5 levels (P=0.028) and ratios of CDH5:HPA binding (P=0.007) distinguished patients with metastatic disease from those that remained metastasis-free. Multivariate analysis showed that the association between CDH5:HPA ratio and the formation of distant metastases was driven by patients with oestrogen receptor (ER+) positive cancer with vascular invasion (VI+). Conclusions: CDH5 levels and the CDH5 glycosylation represent biomarker tests that distinguish patients with metastatic breast cancer from those that remain metastasis-free. The test reached optimal sensitivity and specificity in ER-positive cancers with vascular invasion

    The frequency, nature and impact of GP-assessed avoidable delays in a population-based cohort of cancer patients

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    Background: There is a growing emphasis on the speed of diagnosis as an aspect of cancer prognosis. While epidemiological data in the last decade have quantified diagnostic timeliness and its variation, whether and how often prolonged diagnostic intervals can be considered avoidable is unknown. // Methods: We used data from the English National Cancer Diagnosis Audit (NCDA) on 17,042 patients diagnosed with cancer in 2014. Participating primary care physicians were asked to identify delays in diagnosis that they deemed avoidable, together with the ā€˜settingā€™ of the avoidable delay and key attributable factors. We used descriptive analysis and regression frameworks to assess validity and examine variation in the frequency and nature of avoidable delays. // Results: Among 14,259 patients, 24% were deemed to have had an avoidable delay to their diagnosis. Patients with a reported avoidable delay had a longer median diagnostic interval (92 days) than those without (30 days). Of all avoidable delays, 13% were deemed to have occurred pre-consultation, 49% within primary care, and 38% within secondary care. Avoidable delays were mostly attributed to the test request/performance phase (25%). Multimorbidity was associated with greater odds of avoidable delay (OR for 3+ vs no comorbidity: 1.43 (95% CI 1.25ā€“1.63)), with heterogeneous associations with cancer site. // Conclusion: We have shown that GP-identified instances of avoidable delay have construct validity. Whilst the causes of avoidable diagnostic delays are multi-factorial and occur in different settings and phases of the diagnostic process, their analysis can guide improvement initiatives and enable the examination of any prognostic implications

    Documentation of Apollo 15 samples

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    A catalog is presented of the documentation of Apollo 15 samples using photographs and verbal descriptions returned from the lunar surface. Almost all of the Apollo 15 samples were correlated with lunar surface photographs, descriptions, and traverse locations. Where possible, the lunar orientations of rock samples were reconstructed in the lunar receiving laboratory, using a collimated light source to reproduce illumination and shadow characteristics of the same samples shown in lunar photographs. In several cases, samples were not recognized in lunar surface photographs, and their approximate locations are known only by association with numbered sample bags used during their collection. Tables, photographs, and maps included in this report are designed to aid in the understanding of the lunar setting of the Apollo 15 samples

    Is England's public health nutrition system in crisis? A qualitative analysis of the capacity to feed all in need during the COVID-19 pandemic

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    Methodology: An exploratory methodology was adopted to examine experiences relating to capability and capacity among formal and informal helpers within the PHN domain. An online survey, mainly open-ended questions, was used to capture experiences over the period 2010 - 2020. A mixed sampling strategy, including snowball and convenience sampling, via social media and social network contact-sharing approaches, was adopted. Data was analysed using an inductive thematic approach. Results: A total of 89 participants representing the PHN system in England were recruited over two months. Three main themes and eight sub-themes were identified. The first reflected unequivocal accounts of the impact of austerity and the inability of PHN services to meet demand for food security. The second articulated capacity and capability issues within the system, with geographical variations in service delivery, and a lack of connectivity between central, local government, and third sector providers. These were attributed to widening nutrition and health inequalities. Participants felt that the government needed to invest more technical and financial resources to support public health nutrition. They also felt that schools could play a larger role at local level, but there was a need for a clear national recovery plan, setting out a comprehensive and fully supported national strategy to eradicate food insecurity in England Conclusions: Further in-depth research is needed to continue to track the impact of recovery strategies on food insecure people and the capacity of the PHN system. Urgent investment in the capacity and coordination of PHN services is needed to support food insecure people in England. The UK could include the ratification of the right to food in national laws, in line with global commitments already agreed to by the UK State Party

    The Effect of Moxidectin Treatment on the Equine Hind Gut Microbiome, Metabonome and Feed Fermentation Kinetics in Horses with Very Low Parasite Burdens

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    Seventeen horses, mean 12 Ā± 3.5 years, kept at pasture, with haylage provided and no concentrates. Faecal Egg Counts were conducted September 2015ā€March 2016, no eggs seen, no anthelmintic given. Sampling commenced March 2016, points were 0 (prior), 16, 48 and 168 hours post anthelmintic. Treatments were randomized, nine animals dosed orally with Moxidectin 18.92 mg/g at 0.4 mg/kg bw and eight controls. Three horses from each group were randomly assigned for fermentation kinetics. Sequencing of the 16S rRNA gene was conducted on extracted faecal bacterial DNA, bioinformatics using QIIME assigning operational taxonomic units (OTUs). LEfSe (Segata et al., 2011) was used to identify differentially abundant OTUs. Bacterial metabolic profiles were characterized by 1H NMR spectroscopy (Escalona et al., 2015), from urine, analysed by Principal Components Analysis. Fermentation of hay and oats, separately, were measured by in vitro gas production (Murray et al., 2006), data were analysed by repeated measures ANOVA

    Impact of previous hepatitis B infection on the clinical outcomes from chronic hepatitis C? A population-level analysis

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    Chronic coinfection with hepatitis C virus (HCV) and hepatitis B virus (HBV) is associated with adverse liver outcomes. The clinical impact of previous HBV infection on liver disease in HCV infection is unknown. We aimed at determining any association of previous HBV infection with liver outcomes using antibodies to the hepatitis B core antigen (HBcAb) positivity as a marker of exposure. The Scottish Hepatitis C Clinical Database containing data for all patients attending HCV clinics in participating health boards was linked to the HBV diagnostic registry and mortality data from Information Services Division, Scotland. Survival analyses with competing risks were constructed for time from the first appointment to decompensated cirrhosis, hepatocellular carcinoma (HCC) and liverā€related mortality. Records of 8513 chronic HCV patients were included in the analyses (87 HBcAb positive and HBV surface antigen [HBsAg] positive, 1577 HBcAb positive and HBsAg negative, and 6849 HBcAb negative). Multivariate causeā€specific proportional hazards models showed previous HBV infection (HBcAb positive and HBsAg negative) significantly increased the risks of decompensated cirrhosis (hazard ratio [HR]: 1.29, 95% CI: 1.01ā€1.65) and HCC (HR: 1.64, 95% CI: 1.09ā€2.49), but not liverā€related death (HR: 1.02, 95% CI: 0.80ā€1.30). This is the largest study to date showing an association between previous HBV infection and certain adverse liver outcomes in HCV infection. Our analyses add significantly to evidence which suggests that HBV infection adversely affects liver health despite apparent clearance. This has important implications for HBV vaccination policy and indications for prioritization of HCV therapy

    Morbidity and measures of the diagnostic process in primary care for patients subsequently diagnosed with cancer

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    Background: There is uncertainty regarding how pre-existing conditions (morbidities) may influence the primary care investigation and management of individuals subsequently diagnosed with cancer. / Methods: We identified morbidities using information from both primary and secondary care records among 11,716 patients included in the English National Cancer Diagnosis Audit (NCDA) 2014. We examined variation in 5 measures of the diagnostic process (the primary care interval, diagnostic interval, number of pre-referral consultations, use of primary care-led investigations, and referral type) by both primary care- and hospital records-derived measures of morbidity. / Results: Morbidity prevalence recorded before cancer diagnosis was almost threefold greater using the primary care (75%) vs secondary care-derived measure (28%). After adjustment, there was limited variation in the primary care interval and the number of pre-referral consultations by either definition of morbidity. Patients with more severe morbidities were less likely to have had a primary care-led investigation before cancer diagnosis compared with those without any morbidity (adjusted odds ratio, OR [95% confidence interval]: 0.72 [0.60ā€“0.86] for Charlson score 3+ vs 0; joint P 1.00ā€“1.41], respectively), and more likely to receive an emergency referral (aOR: 1.60 [1.26ā€“2.02] and 1.61 [1.26ā€“2.06], respectively). / Conclusion: Among cancer cases with up to 2 morbidities, there was no evidence of differences in diagnostic processes and intervals in primary care but higher morbidity burden was associated with longer time to diagnosis and higher likelihood of emergency referral
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