Revista Jurídica Digital UANDES
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Arithmetic progressions in binary quadratic forms and norm forms
No full textWe prove an upper bound for the length of an arithmetic progression represented by an irreducible integral binary quadratic form or a norm form, which depends only on the form and the progression's common difference. For quadratic forms, this improves significantly upon an earlier result of Dey and Thangadurai
Dynamics and control of a heat pump assisted azeotropic dividing-wall column for biobutanol purification
No full textAn efficient downstream process has been developed for the acetone-butanol-ethanol (ABE), allowing about 60% energy savings as compared to a conventional separation sequence. This is achievable in an azeotropic dividing-wall column (A-DWC) coupled with a heat pump and applying heat integration. The energy use is reduced to only 2.7 MJ/kg butanol (or 7.5% of the energy content of butanol), but to take full advantage of the energy savings offered by this highly integrated process, the process must be also controllable. This work presents the dynamics and control of this novel A-DWC process used for biobutanol purification.A rigorous, pressure-driven dynamic simulation has been developed in Aspen Plus Dynamics. After adding the required PID controllers (e.g. flow, pressure, liquid level and temperature) to the base-case process, the system can handle small and short disturbances (e.g. 5% change of feed flow rate for 10 min.) but if the disturbance persists for a long time the process shuts down. To solve this problem, the controllability of the system is improved by adding an additional reboiler and condenser to control the temperature on the feed-side stripping section. Moreover, adding concentration controllers ensures that the products purity is kept constant when feed flowrate or composition disturbances occur
Unrecognized bipolar disorder in patients with depression managed in primary care:A systematic review and meta-analysis
No full text Purpose: Bipolar disorder is a common, severe mental health condition and a major financial burden for healthcare systems across the globe. There is some evidence that unrecognized bipolar disorder is prevalent amongst patients with depression in primary care which can lead to non-optimal treatment. However, a systematic synthesis of this literature is lacking. We aimed to determine the percentage of primary care patients who are diagnosed with depression that have unrecognized bipolar disorder. Methods: Medline, Embase, Cochrane and PsycINFO were searched to January 2019. We included quantitative observational studies. Risk of bias was assessed using the Newcastle Ottawa cohort scale. Analyses were performed using random-effects models, heterogeneity was quantified using I 2 and formal tests of publication bias were undertaken. Results: Ten studies with 3803 participants with depression in primary care were included. The pooled prevalence of bipolar disorder in those with depression was 17% (95% CI = 12 to 22). The prevalence of unrecognized bipolar depression was higher in studies which used questionnaires as assessment tools for bipolar disorder compared to studies which used clinical interviews but this difference was not significant (14%, 95% CI = 8 to 20 versus 22%, 95% CI = 16 to 28, Q = 1.27, p = 0.12). The prevalence of unrecognized bipolar disorder was not significantly affected by study-level variations in the risk of bias and we found no evidence for publication bias. Conclusion: Over 3 in 20 patients with depression have unrecognized bipolar disorder in primary care which can lead to harmful patient outcomes. Increased awareness of unrecognition of bipolar disorder in primary care patients with depression and efficient assessment strategies in primary care are warranted. </p
Effects of ‘pre-fracking’ operations on ambient air quality at a shale gas exploration site in rural North Yorkshire, England
No full text Rural observations of air quality and meteorological parameters (NO x , O 3 , NMHCs, SO 2 , PM) were made over a 2.5-year period (2016–2018) before, during and after preparations for hydraulic fracturing (fracking) at a shale gas exploration site near Kirby Misperton, North Yorkshire, England. As one of the first sites to apply for permits to carry out hydraulic fracturing, it has been subject to extensive regulatory and public scrutiny, as well as the focus for a major programme of long-term environmental monitoring. A baseline period of air quality monitoring (starting 2016) established the annual climatology of atmospheric composition against which a 20-week period of intensive activity on the site in preparation for hydraulic fracturing could be compared. During this ‘pre-operational phase’ of work in late 2017, the most significant effect was an increase in ambient NO (3-fold) and NO x (2-fold), arising from a combination of increased vehicle activity and operation of equipment on site. Although ambient NO x increased, air quality limit values for NO 2 were not exceeded, even close to the well-site. Local ozone concentrations during the pre-operational period were slightly lower than the baseline phase due to titration with primary emitted NO. The activity on site did not lead to significant changes in airborne particulate matter or non-methane hydrocarbons. Hydraulic fracturing of the well did not subsequently take place and the on-site equipment was decommissioned and removed. Air quality parameters then returned to the original (baseline) climatological conditions. This work highlights the need to characterise the full annual climatology of air quality parameters against which short-term local activity changes can be compared. Based on this study, changes to ambient NO x appear to be the most significant air quality ahead of hydraulic fracturing. However, in rural locations, concentrations at individual sites are expected to be below ambient air quality limit thresholds. </p
Chronic pulmonary aspergillosis update:A year in review
No full textChronic pulmonary aspergillosis (CPA) is an uncommon, slowly destructive pulmonary disease characterized by progressive cavitation, fibrosis, and pleural thickening. CPA is usually seen in immunocompetent individuals with underlying respiratory disorders. Estimates suggest that up to 3 million people are affected worldwide causing high rates of morbidity and mortality. Pulmonary tuberculosis (TB) seems to be the most relevant driver for the global burden of CPA with estimates suggesting about 1.2 million patients with CPA as a sequel to TB. Diagnosis of CPA is often challenging and delayed and should be based upon a combination of characteristics. The first guidelines for the diagnosis and management of CPA were published in 2016 jointly by the European Society for Clinical Microbiology and Infectious Diseases (ESCMID), the European Respiratory Society (ERS), and the European Confederation of Medical Mycology (ECMM). CPA continues to receive significant public attention, which resulted in almost 150 newly published papers during 2017. The aim of this mini-review is to highlight the most important published papers from January 2017 to April 2018 to provide an update on current developments in the field of CPA.</p
Enhancing Disease Diagnosis: Biomedical Applications of Surface-Enhanced Raman Scattering:Biomedical applications of surface-enhanced raman scattering
No full textSurface-enhanced Raman scattering (SERS) has recently gained increasing attention for the detection of trace quantities of biomolecules due to its excellent molecular specificity, ultrasensitivity, and quantitative multiplex ability. Specific single or multiple biomarkers in complex biological environments generate strong and distinct SERS spectral signals when they are in the vicinity of optically active nanoparticles (NPs). When multivariate chemometrics are applied to decipher underlying biomarker patterns, SERS provides qualitative and quantitative information on the inherent biochemical composition and properties that may be indicative of healthy or diseased states. Moreover, SERS allows for differentiation among many closely-related causative agents of diseases exhibiting similar symptoms to guide early prescription of appropriate, targeted and individualised therapeutics. This review provides an overview of recent progress made by the application of SERS in the diagnosis of cancers, microbial and respiratory infections. It is envisaged that recent technology development will help realise full benefits of SERS to gain deeper insights into the pathological pathways for various diseases at the molecular level.</p
Measurements of inclusive and differential fiducial cross-sections of tt¯ production with additional heavy-flavour jets in proton-proton collisions at √s =13 TeV with the ATLAS detector
No full textSupporting medication adherence for adults with cystic fibrosis:A randomised feasibility study
No full text Background: Preventative medication reduces hospitalisations in people with cystic fibrosis (PWCF) but adherence is poor. We assessed the feasibility of a randomised controlled trial of a complex intervention, which combines display of real time adherence data and behaviour change techniques. Methods: Design: Pilot, open-label, parallel-group RCT with concurrent semi-structured interviews. Participants: PWCF at two Cystic Fibrosis (CF) units. Eligible: aged 16 or older; on the CF registry. Ineligible: post-lung transplant or on the active list; unable to consent; using dry powder inhalers. Interventions: Central randomisation on a 1:1 allocation to: (1) intervention, linking nebuliser use with data recording and transfer capability to a software platform, and behavioural strategies to support self-management delivered by trained interventionists (n = 32); or, (2) control, typically face-to-face meetings every 3 months with CF team (n = 32). Outcomes: RCT feasibility defined as: recruitment of ≥ 48 participants (75% of target) in four months (pilot primary outcome); valid exacerbation data available for ≥ 85% of those randomised (future RCT primary outcome); change in % medication adherence; FEV 1 percent predicted (key secondaries in future RCT); and perceptions of trial procedures, in semi-structured interviews with intervention (n = 14) and control (n = 5) participants, interventionists (n = 3) and CF team members (n = 5). Results: The pilot trial recruited to target, randomising 33 to intervention and 31 to control in the four-month period, June-September 2016. At study completion (30th April 2017), 60 (94%; Intervention = 32, Control =28) participants contributed good quality exacerbation data (intervention: 35 exacerbations; control: 25 exacerbation). The mean change in adherence and baseline-adjusted FEV 1 percent predicted were higher in the intervention arm by 10% (95% CI: -5.2 to 25.2) and 5% (95% CI -2 to 12%) respectively. Five serious adverse events occurred, none related to the intervention. The mean change in adherence was 10% (95% CI: -5.2 to 25.2), greater in the intervention arm. Interventionists delivered insufficient numbers of review sessions due to concentration on participant recruitment. This left interventionists insufficient time for key intervention procedures. A total of 10 key changes that were made to RCT procedures are summarised. Conclusions: With improved research processes and lower monthly participant recruitment targets, a full-scale trial is feasible. Trial registration: ISRCTN13076797. Prospectively registered on 07/06/2016. </p
The UbiX flavin prenyltransferase reaction mechanism resembles Class I terpene cyclase chemistry
No full textThe UbiX-UbiD enzymes are widespread in microbes, acting in concert to decarboxylate alpha-beta unsaturated carboxylic acids using a highly modified flavin cofactor, prenylated FMN (prFMN). UbiX serves as the flavin prenyltransferase, extending the isoalloxazine ring system with a fourth non-aromatic ring, derived from sequential linkage between a dimethylallyl moiety and the FMN N5 and C6. Using structure determination and solution studies of both dimethylallyl monophosphate (DMAP) and dimethyallyl pyrophosphate (DMAPP) dependent UbiX enzymes, we reveal the first step, N5-C1’ bond formation, is contingent on the presence of a dimethylallyl substrate moiety. Hence, an SN1 mechanism similar to other prenyltransferases is proposed. Selected variants of the (pyro)phosphate binding site are unable to catalyse subsequent Friedel-Crafts alkylation of the flavin C6, but can be rescued by addition of (pyro)phosphate. Thus, retention of the (pyro)phosphate leaving group is required for C6-C3’ bond formation, resembling pyrophosphate initiated class I terpene cyclase reaction chemistry
Evaluating the environmental sustainability of cakes
No full textCakes are a favourite food across the globe and yet little is known about their environmental sustainability. To address this research gap, this paper evaluates the life cycle environmental impacts associated with the production and consumption of industrially-produced cakes. The following main product categories are considered: whole cakes, cake slices, pies, cupcakes and cheesecake. The results reveal that whole cakes have the lowest impacts for 13 out of 18 categories considered. Cheesecake is environmentally the least sustainable option, with all impacts but terrestrial ecotoxicity higher than any other cake type. Raw materials are the major contributors to the majority of impact categories (22%–98%), followed by packaging and manufacturing. Wheat flour, sugar, palm oil and milk-based ingredients are the main hotspots in the life cycle. A range of improvement opportunities is considered across the supply chain. For example, decreasing sugar content in cakes by 30% would lower the impacts by up to 3%–11% while reducing the amount of packaging and energy used in manufacturing would lower the impacts cumulatively by 9%–23%. Minimising waste would decrease water ecotoxicity by 6%–28%. Based on annual consumption in the UK, the cakes sector contributes 2% to the energy consumption and 1% to the GHG emissions of the whole food sector. The results of this work can assist the industry and government in benchmarking the sector and minimising its environmental impacts. The findings will also be of interest to consumers in identifying environmentally more sustainable cake alternatives