695915 research outputs found
Sort by
PKU-2: an intrinsically microporous aluminoborate with the potential in selective gas separation of CO2/CH4 and C2H2/C2H4
No full textSelective gas adsorption and separation were intensively investigated for porous materials like metal-organic frameworks (MOFs) and Zeolites. In this study, an intrinsically microporous aluminoborate, PKU-2, with an extra-large one dimensional channel (~ 9.6 Å) was discovered for the first time to exhibit selective CO2 and C2H2 adsorption over CH4 and C2H4, respectively. Incorporation of Cr3+ and Fe3+ ions into the framework could effectively enlarge the specific surface area in comparison with the pristine PKU-2, which is accompanied with a significant enhancement of gas adsorption capacities for CO2 and C2H2 to 3.9 and 2.86 mmol/g, respectively, for Fe-PKU-2, and a slight decrease of gas separation selectivities. The high gas adsorption capacities and selectivities together with their high thermal stability imply their potential practice applications for environment and energy-relevant gas adsorption and separation
Exploring the relationships between illness beliefs and psychosis symptoms among Black African and Caribbean people with non-affective psychosis
No full textBlack African and Caribbean people in the UK have the highest rates of psychosis and poorest access, experiences and outcomes of mental health services than other ethnic groups. Previous research suggests that beliefs about mental health problems may influence emotional responses, coping behaviours and outcomes in psychosis. The aim of this study was to examine the causal attributions and illness perceptions of 51 Black African and Caribbean people with non-affective psychosis and their associations with psychosis symptoms. Black service users with non-affective psychosis most frequently attributed mental health problems to psychosocial factors, though spiritual, biological and substance abuse explanations were also provided. Endorsing a psychosocial explanation for psychosis was associated with less severe negative symptoms. More negative or threatening illness perceptions were correlated with greater negative, general and overall symptom severity in psychosis. Psychological formulations and interventions for Black people experiencing psychosis should consider personalised beliefs about their mental health problems as this may facilitate improvements in symptoms. Further longitudinal research is warranted in larger samples to examine psychological causal mechanisms linking illness beliefs and psychosis outcomes
The paradox of forbs in grasslands and their legacy of the Mammoth steppe
No full textThe grassland biome harbors great biodiversity and includes ecosystems used extensively by humans. Although graminoids lend grasslands their characteristic appearance, forbs contribute significantly to their species, phylogenetic, and functional diversity. Yet, in terms of abundance the forbs often play a subordinate role.This subordinate role of forbs in grasslands may be a relatively recent phenomenon. Evidence is mounting that forbs made up a major part of the richness and were abundant in the extensive and highly productive grasslands of the Pleistocene: the Mammoth Steppe. As a legacy of their past prevalence under intensive grazing by megafauna, we hypothesize that forbs were, and still are, dependent on niche construction by mammalian herbivores. We suggest that the high species richness of forbs in grasslands globally merits attention along with management actions tailored to sustain them. <br/
Specifications of the ACMG/AMP variant interpretation guidelines for germline TP53 variants
No full textGermline pathogenic variants in TP53 are associated with Li-Fraumeni syndrome (LFS), a cancer predisposition disorder inherited in an autosomal dominant pattern associated with high risk of malignancy, including early onset breast cancers, sarcomas, adrenocortical carcinomas, and brain tumors. Intense cancer surveillance for individuals with TP53 germline pathogenic variants is associated with reduced cancer-related mortality. Accurate and consistent classification of germline variants across clinical and research laboratories is important to ensure appropriate cancer surveillance recommendations. Here, we describe the work performed by the Clinical Genome Resource TP53 Variant Curation Expert Panel (ClinGen TP53 VCEP) focused on specifying the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) guidelines for germline variant classification to the TP53 gene. Specifications were developed for twenty ACMG/AMP criteriawhile nine were deemed not applicable. The original strength level for ten criteria was also adjusted due to current evidence. Use of TP53-specific guidelines and sharing of clinical data amongst experts and clinical laboratories led to a decrease in variants of uncertain significancefrom 28% to 12% compared with the original guidelines. The ClinGen TP53 VCEP recommends the use of these TP53-specific ACMG/AMP guidelines as the standard strategy for TP53 germline variant classification.<br/
Ascent of the herbivores, decline of the carnivores: The social stratification of eating profiles in Italy, 1997–2016
No full textUsing data from the Multipurpose Survey of Daily Life by ISTAT, we analyse the profiling and social stratification of eating styles among Italian adults from 1997 to 2016. We apply Latent Class Analysis on a set of common foods to document the existence of six consumption clusters,(herbivore, carnivore, hedonist, enhanced Mediterranean, paucivore, omnivore) and their relative size over time. We then illustrate how gender and education are associated with each of the identified clusters and document the evolution of their gradients over time. Results point to an increase in the relative size of the herbivores and omnivores, a substantial stability of the hedonists and paucivores, and a decline of the carnivores and enhanced Mediterraneans. Moreover, our findings highlight a substantial social stratification of eating profiles and show that, within a broad picture of persistence, gender and education became more important in affecting the propensity of adopting certain profiles
From BRCA1 to polygenic risk scores - Mutations associated risks in breast cancer-related genes
No full textThere has been huge progress over the last 30 years in identifying the familial component of breast cancer. Summary: Currently around 20% is explained by the high-risk genes BRCA1 and BRCA2, a further 2% from other high penetrance genes and around 5% from the moderate risk genes ATM and CHEK2. In contrast the more than 300 low penetrance Single Nucleotide Polymorphisms (SNPs) now account for around 28% and are predicted to account for most of the remaining 45% yet to be found. Even for high-risk genes which confer a 40-90% risk of breast cancer these SNPs can substantially affect the level of breast cancer risk. Indeed, the strength of family history and hormonal and reproductive factors are very important in assessing risk even for a BRCA carrier. Risks of contralateral breast cancer are also affected by SNPs as well as the presence of high or moderate risk genes. Genetic testing using gene panels is now commonplace. Key-messages: There is need for a more parsimonious approach to panels only testing those genes with a definite 2-fold increased risk, and only testing the genes with challenging management implications, such as CDH1and TP53, where there is strong clinical indication to do so. Testing of SNPs alongside genes is likely to provide more accurate risk assessment
Estimation and Optimal Structure Selection of High-Dimensional Toeplitz Covariance Matrix
No full textThe estimation of structured covariance matrix arises in many elds. An appropriate covariance structure not only improves the accuracy of covariance estimation but also increases the eciency of mean parameter estimators in statistical models. In this paper, a novel statistical method is proposed, which selects the optimal Toeplitz covariance structure and estimates the covariance matrix, simultaneously. An entropy loss function with nonconvex penalty is employed as a matrix-discrepancy measure, under which the optimal selection of sparse or nearly sparse Toeplitz structure and the parameter estimators of covariance matrix are made, simultaneously, through its minimization. The cases of both low-dimensional (p n) and high-dimensional (p > n) covariance matrix estimation are considered. The resulting Toeplitz structured covariance estimators are guaranteed to be positive denite and consistent. Asymptotic properties are investigated and simulation studies are conducted, showing that very high accurate Toeplitz covariance structure estimation is made. The proposed method is then applied t
Demyelination following anti-TNFɑ
No full textObjective: To establish the incidence of demyelination in patients who have received anti-tumour necrosis factor (anti-TNFɑ) therapy, through analysis of adverse events reported in a prospective cohort of patients receiving biological therapies. Methods: A cohort study was performed on prospectively acquired data via the British Society for Rheumatology Biologics Register in Rheumatoid Arthritis. All potential demyelinating events during follow-up were extracted and classified as definite, probable or possible blinded to treatment data. The point of starting an anti-TNF therapy in individuals with no prior reported demyelination was the time of exposure. Crude rates of demyelination and standardised incident rates (SIR) compared to the general UK population were calculated. Results: 35 individuals with demyelinating events were identified from a total pool of 13,489. Median age at study entry was 44 years and median disease duration 8 years; 71% were female. Events occurred a median of 3 (IQR 1-5) years from the start of first anti-TNF therapy. 26 events occurred in individuals still taking anti-TNFɑ therapy; of the other 9, 6 were within 90 days of drug withdrawal. The raw incidence of demyelination was 19.7/100,000 patient years (95%CI 13.7-27.3). SIR in the whole population was 1.38 (95%CI 0.96-1.92) and 0.83 (0.51-1.26) limited to definite/probable cases. Conclusions: Demyelination following anti-TNF therapy is uncommon. Patients receiving anti-TNFɑ therapy show a marginally increased SIR; this is lost in sensitivity analyses. Patients concerned about anti-TNFɑ- associated demyelination can be relatively reassured by these data.<br/
The impact of ionic surfactants on the crystallisation of glycine polymorphs
No full textThe glycine polymorphs have provided a rich and challenging tapestry for crystal growth andpolymorphism studies. In this new contribution we report some preliminary studies of theimpact of two ionic surfactants on the morphologies and the competitive crystallisation of theα and γ polymorphs. We find both selective growth inhibition and acceleration combined withfascinating crystal aggregates. The role of both monomeric and micellar forms of thesurfactants are explored and discussed in terms of nucleation and crystal growth processes
A review of sophorolipid production from alternative feedstocks for the development of a localized selection strategy
No full textThe replacement of traditional petroleum-based surfactants with renewable biosurfactants is a key part of the transition towards a circular economy. Sophorolipids are the most commercially adopted biosurfactant due to the existence of high productivity fermentation process, excellent surface and interfacial tension properties and because the main producer organism Starmerella bombicola is non-pathogenic/non-GMO. However, the current large-scale production of sophorolipids still utilizes purified substrates such as glucose and oleic acid. This is a major reason their price is an order of magnitude higher than traditional surfactants, severely limiting their commercial adoption. Hence, implementation of sophorolipid production from alternative biomass byproducts and wastes is crucial. This review illustrates the potential performance of alternative feedstocks as sources of sugars, fatty acids and nitrogen for sophorolipid production. Important studies where alternative feedstocks outperformed purified substrates under the same conditions, as well as high overall production of sophorolipid using sophisticated fermentation schemes are highlighted. Promising performance such as productivities of up to 2.4 g/L/h currently exist with processes based on alternative feedstocks. Important knowledge gaps within the literature are also identified, such as the need to combine alternative feedstocks to eliminate the use of purified substrates. Future improvement of productivity on alternative feedstocks could be achieved via implementation of sophisticated fermentation schemes to either improve cell titer during growth or to improve SL production itself, such as in-situ separation of sophorolipids. Selection criteria were produced using key performance factors identified from the literature, together with other factors such as available quantity, price and logistics as well as the potential for integrated biorefining. These selection criteria were then applied to the UK as a case study. In the future, the framework developed could be applied to feedstock assessment and selection for localized sophorolipid production in various locations around the world