DPP-4 inhibitor dose selection according to manufacturer specifications:A Contemporary Experience From UK General Practice

Recently, 2 dipeptidyl peptidase-4 (DPP-4) inhibitors, sitagliptin and saxagliptin, adjusted dosing specification from creatinine clearance to glomerular filtration rate, more typically reported in routine laboratory tests. This cross-sectional study examines all DPP-4 inhibitor initiations that require dose adjustment and the dose selection using data from UK general practice. Results indicate that 34% of patients taking a nonlinagliptin DPP-4 inhibitor were given a higher dose and 11% a lower dose than specified in the Summary of Product Characteristics. This reinforces the deviation from Summary of Product Characteristics prescription of DPP-4 inhibitors identified in earlier studies despite improvement in compatibility with routine reporting. (C) 2019 The Authors. Published by Elsevier Inc

The relation between cigarette price and hand-rolling tobacco consumption in the UK: an ecological study

OBJECTIVES: Cigarette price increases reduce smoking prevalence but as a tobacco control policy are undermined by the availability of lower cost alternatives such as hand-rolling tobacco. The aim of this descriptive study is to explore time trends in the price of manufactured cigarettes and hand-rolling tobacco, and in the numbers of people who smoke these products, over recent years in the UK. SETTINGS AND PARTICIPANTS: UK. OUTCOME MEASURES: Trends in the most popular price category (MPPC) data for cigarettes and hand-rolling tobacco from 1983 to 2012 adjusted for inflation using the Retail Price Index, and trends in smoking prevalence and the proportion of smokers using hand-rolling tobacco from 1974 to 2010. RESULTS: After adjustment for inflation, there was an increase in prices of manufactured cigarettes and hand-rolling tobacco between 1983 and 2012. Between 1974 and 2010, the prevalence of smoking fell from 45% to 20%, and the estimated total number of smokers from 25.3 to 12.4 million. However the number of people smoking hand-rolling tobacco increased from 1.4 to 3.2 million, and MPPC cigarette price was strongly correlated with number of people smoking hand-rolling tobacco. CONCLUSIONS: Although the ecological study design precludes conclusions on causality, the association between increases in manufactured cigarette price and the number of people smoking hand-rolling tobacco suggests that the lower cost of smoking hand-rolling tobacco encourages downtrading when cigarette prices rise. The magnitude of this association indicates that the lower cost of hand-rolling tobacco seriously undermines the use of price as a tobacco control measure

Tailoring porosity and rotational dynamics in a series of octacarboxylate metal-organic frameworks

Modulation and precise control of porosity of metal-organic frameworks (MOFs) are of critical importance to their materials function. Here we report the first modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs show absence of network interpenetration, robust structures and permanent porosity. Interestingly, activated MFM-185a shows a record high BET surface area of 4734 m2 g-1 for an octacarboxylate MOF. These MOFs show remarkable CH4 and CO2 adsorption properties, notably with simultaneously high gravimetric and volumetric deliverable CH4 capacities of 0.24 g g-1 and 163 v/v (298 K, 5-65 bar) recorded for MFM-185a due to selective elongation of tubular cages. Dynamics of molecular rotors in deuterated MFM-180a-d16 and MFM-181a-d16 were investigated by variable-temperature 2H solid state NMR spectroscopy to reveal the reorientation mechanisms within these materials. Analysis of the flipping modes of the mobile phenyl groups on the linkers, their rotational rates and transition temperatures, paves the way to controlling and understanding the role of molecular rotors through organic linker design within porous MOF materials

High efficiency synthesis of HKUST-1 under mild conditions with high BET surface area and CO2 uptake capacity

This study focuses on the development of a hydrothermal method for the rapid synthesis of good quality copper benzene-1,3,5-tricarboxylate (referred to as HKUST-1) with high yield under mild preparation conditions to address the issues associated with reported methods. Different synthesis conditions and activation methods were studied to understand their influence on the properties of HKUST-1. It was found that mixing the precursors at 50 °C for 3 h followed by activation via methanol refluxing led to the formation of a product with the highest BET specific surface area of 1615 m2/g and a high yield of 84.1%. The XRD and SEM data illustrated that the product was highly crystalline. The sample was also tested on its capacity in CO2 adsorption. The results showed strong correlation between surface area of the sample and its CO2 uptake at 1 bar and 27 °C. The HKUST-1 prepared in this study demonstrated a high CO2 uptake capacity of 4.2 mmol/g. It is therefore concluded that this novel and efficient method can be used in the rapid preparation of HKUST-1 with high surface area and CO2 uptake capacity

Language Models for Ancient Greek

Το BERT είναι ένα προ-εκπαιδευμένο Γλωσσικό Μοντέλο το οποίο αναπτύχθηκε από την ομάδα της Google AI Language το 2018, που πετυχαίνει κορυφαίες επιδόσεις σε πολλά προβλήματα Επεξερασίας Φυσικής Γλώσσας. Είναι ένα επαναστατικό μοντέλο που μπο- ρεί να χρησιμοποιηθεί για την επίλυση σχεδόν οποιουδήποτε προβλήματος απατεί διαχείριση φυσικής γλώσσας. Ήδη, έχει εφαρμοσθεί με επιτυχία σε πληθώρα γλωσσών πέρα από τα Αγγλικά, όπως Γαλλικά, Ισπανικά, αλλά ακόμη και σε Ελληνικά και Λατινικά. Ο στόχος αυτής της πτυχιακής ήταν η δημιουργία ενός Γλωσσικού Μοντέλου για την Αρχαία Ελληνική γλώσσα βασισμένο σε μια αρχιτεκτονική τύπου BERT, και στη συνέχεια η εφαρμογή του σε κάποιο πρόβλημα, συγκεκριμένα στην αναγώριση ετικετών μέρους του λόγου. Υπήρχαν δύο βασικά βήματα που έπρεπε να πραγματοποιηθούν για να αναπτυ- χθεί το μοντέλο. Αρχικά, υπήρξε το κομμάτι της συλλογής δεδομένων, και στη συνέχεια η εκπαίδευση ενός γλωσσικού μοντέλου με τα δεδομένα που αποκτήθηκαν. Όσον αφορά το κομμάτι της συλλογής δεδομένων, πραγματοποιήθηκε αρκετή έρευνα προκειμένου να βρεθούν διαθέσιμες στο κοινό πηγές με δεδομένα απλού κειμένου, αλλά δεν βρέθηκαν πολλά. Συνολικά, ο όγκος των δεδομένων που μπορέσαμε να συλλέξουμε ήταν λίγο μικρότερος από 450 MB. Αυτό ήταν ένα σημαντικό πρόβλημα, καθώς τα πε- ρισσότερα μοντέλα που βασίζονται σε αρχιτεκτονική BERT είχαν εκπαιδευτεί με όγκους δεδομένων της κλίμακας των 30-50 GB. Όσον αφορά το κομμάτι της εκπαίδευσης, η προ-εκπαίδευση και το μοντέλο RoBERTa επιλέχθηκαν ως πλαίσιο για το Μοντέλο της Αρχαίας Ελληνικής Γλώσσας, αφού έχουν επιδείξει καλύτερες επιδόσεις από άλλες παραλλαγές του BERT. Ο στόχος εκπαίδευσης ήταν αυτός του Masked Language Modeling με δυναμική μάσκα. Απροσδόκητα, τα αποτελέσματα είχαν δύο πλευρές. Από την μία πλευρά, το Γλωσσικό Μοντέλο αδυνατούσε να μάθει εις βάθος την Αρχαία Ελληνική Γλώσσα διότι δεν εκπαιδευόταν με αρκετά δεδομένα. Δοκιμάστηκαν πολλές ιδέες, όπως η μείωση του μεγέθους του μοντέλου και ο συντονισμός των υπερπαραμέτρων με μπαεσιανή βελτιστοποίηση, αλλά καμία δεν έδωσε καλά αποτελέσματα. Από την άλλη πλευρά, όταν το εφαρμόσαμε στο πρόβλημα αναγνώρισης ετικετών μέρους του λόγου, τα αποτέσματα είναι αρκετά καλά, κάτι το οποίο συνιστά πως το μοντέλο είχε όντως κατανοήσει ορισμένες πτυχές της Αρχαίας Ελληνικής Γλώσσας. Ρίχνοντας μια ματιά στις καμπύλες εκπαίδευσης, μπορούμε να δούμε ότι το μοντέλο σίγουρα μαθαίνει κάτι, καθώς η αντικειμενική συνάρτηση συνεχίζει να μειώνεται, μέχρι ένα σημείο στο οποίο συγκλίνει. Πιστεύουμε ότι αυτή η συμπεριφορά οφείλεται στην έλλειψη ενός πολύ μεγαλύτερου σώματος δεδομένων. Εάν διατεθούν περισσότερα δεδομένα στο μέλλον, σίγουρα θα άξιζε να δοκιμαστεί ξανά αυτή η προσέγγιση. Γι' αυτό τον λόγο, ο κώδικας για τη λήψη των δεδομένων και την εκπαίδευση ενός μοντέλου διατίθεται στη ηλεκτρονική διεύθυνση https://github.com/AndrewSpano/BSc-Thesis.BERT is a pre-trained Language Model introduced by Google AI Language in 2018, that manages to achieve state-of-the-art results on many downstream tasks. It is a revolutionary model that can be used to tackle almost any NLP task. It has also been successfully applied to other languages apart from English, such as French, Spanish and even Greek and Latin. The goal of this thesis was to create a Language Model for the Ancient Greek language based on a BERT-like architecture, and then fine-tune it to some downstream task, specifically Part-of-Speech tagging. There were two main steps that needed to be taken in order to develop the model. First, there was the data collection part, and then training a language model with the data acquired. Regarding the data collection part, a lot of research was done in order to find publicly available sources with plain-text data, but not much was found. In total, the amount of data that we were able to collect was a bit less than 450 MB. This was a major problem, as most BERT-like models had been trained on corpora in the scale of 30-50 GB. Regarding the training part, the RoBERTa pre-training and model were chosen as a frame- work for the Ancient Greek Language Model, since it had demonstrated better performance than other variants. The training objective was that of Masked Language Modelling with dynamic masking. Unexpectedly, the results were two-fold. One the one hand, the Language Model kept underfitting due to the fact that it wasn’t seeing enough data. Many ideas were tried such as reducing the model size and tuning the hyperparameters with bayesian optimization, but none yielded good results. On the other hand, when fine-tuning for PoS Tagging, the results were reasonably good, which suggests that the Language Model has learnt important aspects of the Ancient Greek language. By taking a look at the training curves, we can see that the model is definitely learning something as the loss keeps decreasing, up until a point where it converges. We strongly believe that this underfitting effect is due to the lack of a much larger corpora. If more data is made available in the future, it would be definitely worth trying out again this approach. That’s why the code for downloading the data and training a model is made available at https://github.com/AndrewSpano/BSc-Thesis

Tuning Ionic and Electronic Conductivities in the "Hollow" Perovskite { en}MAPbI₃

The recently developed family of 3D halide perovskites with general formula (A)1-x(en)x(M)1-0.7x(I)3-0.4x (A = MA, FA; M = Pb2+, Sn2+ en = ethylenediammonium), often referred to as "hollow"perovskites, exhibits exceptional air stability and crystallizes in the high symmetry α phase at room temperature. These properties are counterintuitive, considering that these structures include the large divalent en cation charge-compensated by vacancies of Pb cations and I anions. Moreover, the understanding of their transport behavior is incomplete. To provide new insights into the ionic and electronic transport properties of these "hollow"perovskites, we performed DC polarization experiments and ab initio calculations on the {en}MAPbI3 material. We observe large variations of ionic and electronic conductivities with en concentration, which can be explained by charge and site arguments in conjunction with trapping effects. The latter is reflected by the increase of the activation energies for iodide ion transport with higher en content that we observe from both experimental and computational results. The connection between these transport phenomena and the stability of "hollow"perovskite materials and devices is discussed. </p

Out-of-Plane Mechanical Properties of 2D Hybrid Organic-Inorganic Perovskites by Nanoindentation

2D layered hybrid organic-inorganic perovskites (HOIPs) have demonstrated improved stability and promising photovoltaic performance. The mechanical properties of such functional materials are both fundamentally and practically important to achieve both high performance and mechanical stable (flexible) devices. Here we report the mechanical properties of a series of 2D layered lead iodide HOIPs and investigate the role of structural sub-units (e.g., variation of the length of the organic spacer molecules -R and the number of inorganic layer -n) on the mechanical properties. While 2D HOIPs have much lower nominal elastic moduli and hardness than 3D HOIPs, larger n number and shorter R lead to stiffer materials. DFT simulations showed a similar trend to the experimental results. We compared these findings with other 2D layered crystals and shed light on routes to further tune the out-of-plane mechanical properties of 2D layered HOIPs

Alternative Organic Spacers for More Efficient Perovskite Solar Cells Containing Ruddlesden-Popper Phases

The halide perovskite Ruddlesden-Popper (RP) phases are a homologous layered subclass of solution-processable semiconductors that have aroused great attention, especially for developing long-term solar photovoltaics. They are defined as (A′)2(A)n-1PbnX3n+1 (A′ = spacer cation, A = cage cation, and X = halide anion). The orientation control of low-temperature self-assembled thin films is a fundamental issue associated with the ability to control the charge carrier transport perpendicular to the substrate. Here we report new chemical derivatives designed from a molecular perspective using a novel spacer cation 3-phenyl-2-propenammonium (PPA) with conjugated backbone as a low-temperature strategy to assemble more efficient solar cells. First, we solved and refined the crystal structures of single crystals with the general formula (PPA)2(FA0.5MA0.5)n-1PbnI3n+1 (n = 2 and 3, space group C2) using X-ray diffraction and then used the mixed halide (PPA)2(Cs0.05(FA0.88MA0.12)0.95)n-1Pbn(I0.88Br0.12)3n+1 analogues to achieve more efficient devices. While forming the RP phases, multiple hydrogen bonds between PPA and inorganic octahedra reinforce the layered structure. For films we observe that as the targeted layer thickness index increases from n = 2 to n = 4, a less horizontal preferred orientation of the inorganic layers is progressively realized along with an increased presence of high-n or 3D phases, with an improved flow of free charge carriers and vertical to substrate conductivity. Accordingly, we achieve an efficiency of 14.76% for planar p-i-n solar cells using PPA-RP perovskites, which retain 93.8 ± 0.25% efficiency with encapsulation after 600 h at 85 °C and 85% humidity (ISOS-D-3)

Exposure to point-of-sale displays and changes in susceptibility to smoking: findings from a cohort study of school students

AimsTo investigate the association between frequency of visiting shops and noticing of tobacco point-of-sale (PoS) displays and the development of susceptibility to smoking, or smoking uptake, in secondary school students.DesignTwo surveys of a school based cohort study carried out in 2011 and 2012.SettingsNottinghamshire, UK.ParticipantsA total of 2270 children aged 11–16 years from eight schools in Nottinghamshire.MeasurementsWe investigated changes in susceptibility to smoking and smoking status in relation to frequency of visiting shops and noticing PoS displays and number of tobacco brands recognized, controlling for a range of potential confounders. Susceptibility to smoking was defined using a set of three questions covering intentions to try smoking, to smoke within the next year and likelihood of smoking if a best friend offered a cigarette. For the analysis we used multinomial logistic regression.FindingsAmong non-susceptible never smokers, noticing PoS displays more frequently was associated independently with an increased risk of becoming susceptible to smoking [adjusted relative risk ratio (RRR) = 1.74; 99% confidence interval (CI) = 1.13–2.69], but was not associated with smoking uptake. Recognizing a higher number of brands among non-susceptible never smokers doubled the risk of becoming susceptible to smoking and of becoming a smoker, but this did not have a significant effect on transition to smoking among susceptible never smokers. Frequency of noticing tobacco PoS displays was not associated significantly with smoking uptake among those who were susceptible never smokers at baseline.ConclusionsNoticing tobacco point-of-sale displays more often and recognizing a higher number of tobacco brands is associated with an increased risk of becoming susceptible to smoking among adolescents in the United Kingdom, and recognizing a higher number of brands is associated positively with an increased risk of smoking uptake

Hausdorff spectrum of harmonic measure

For every non-elementary hyperbolic group, we show that for every random walk with finitely supported admissible step distribution, the associated entropy equals the drift times the logarithmic volume growth if and only if the corresponding harmonic measure is comparable with Hausdorfff measure on the boundary. Moreover, we introduce one parameter family of probability measures which interpolates a Patterson-Sullivan measure and the harmonic measure, and establish a formula of Hausdorff spectrum (multifractal spectrum) of the harmonic measure. We also give some finitary versions of dimensional properties of the harmonic measure