22 research outputs found
Accelerating the Discovery of g-CN-Supported Single Atom Catalysts for Hydrogen Evolution Reaction: A Combined DFT and Machine Learning Strategy
Two-dimensional materials supported by single atom catalysis (SACs) are
foreseen to replace platinum for large-scale industrial scalability of
sustainable hydrogen generation. Here, a series of metal (Al, Sc, Ti, V, Cr,
Mn, Fe, Ni, Cu, Zn) and non-metal (B, C, N, O, F, Si, P, S, Cl) single atoms
embedded on various active sites of g-CN are screened by DFT
calculations and six machine learning (ML) algorithms (support vector
regression, gradient boosting regression, random forest regression, AdaBoost
regression, multilayer perceptron regression, ridge regression). Our results
based on formation energy, Gibbs free energy and bandgap analysis demonstrate
that the single atoms of B, Mn and Co anchored on g-CN can serve as
highly efficient active sites for hydrogen production. The ML model based on
support vector regression (SVR) exhibits the best performance to accurately and
rapidly predict the Gibbs free energy of hydrogen adsorption (GH )
for the test set with a lower mean absolute error (MAE) and a high coefficient
of determination (R) of 0.45 and 0.81, respectively. Feature selection
based on the SVR model highlights the top five primary features: formation
energy, bond length, boiling point, melting point, and valance electron as key
descriptors. Overall, the multistep work-flow employed through DFT calculations
combined with ML models for efficient screening of potential hydrogen evolution
reaction (HER) from g-CN-based single atom catalysis can significantly
contribute to the catalyst design and fabrication.Comment: 10 pages, 4 figure
Unhealthy Gambling Amongst New Zealand Secondary School Students: An Exploration of Risk and Protective Factors
This study sought to determine the prevalence of gambling and unhealthy gambling behaviour and describe risk and protective factors associated with these behaviours amongst a nationally representative sample of New Zealand secondary school students (n = 8,500). Factor analysis and item response theory were used to develop a model to provide a measure of ‘unhealthy gambling’. Logistic regressions and multiple logistic regression models were used to investigate associations between unhealthy gambling behaviour and selected outcomes. Approximately one-quarter (24.2 %) of students had gambled in the last year, and 4.8 % had two or more indicators of unhealthy gambling. Multivariate analyses found that unhealthy gambling was associated with four main factors: more accepting attitudes towards gambling (pp = 0.0061); being worried about and/or trying to cut down on gambling (p p = 0.0009). Unhealthy gambling is a significant health issue for young people in New Zealand. Ethnic and social inequalities were apparent and these disparities need to be addressed
Intravenous doxycycline, azithromycin, or both for severe scrub typhus
BACKGROUND: The appropriate antibiotic treatment for severe scrub typhus, a neglected but widespread reemerging zoonotic infection, is unclear.
METHODS: In this multicenter, double-blind, randomized, controlled trial, we compared the efficacy of intravenous doxycycline, azithromycin, or a combination of both in treating severe scrub typhus. Patients who were 15 years of age or older with severe scrub typhus with at least one organ involvement were enrolled. The patients were assigned to receive a 7-day course of intravenous doxycycline, azithromycin, or both (combination therapy). The primary outcome was a composite of death from any cause at day 28, persistent complications at day 7, and persistent fever at day 5.
RESULTS: Among 794 patients (median age, 48 years) who were included in the modified
intention-to-treat analysis, complications included those that were respiratory (in 62%), hepatic (in 54%), cardiovascular (in 42%), renal (in 30%), and neurologic (in 20%). The use of combination therapy resulted in a lower incidence of the composite primary outcome than the use of doxycycline (33% and 47%, respectively), for a risk difference of −13.3 percentage points (95% confidence interval [CI], (21.6 to −5.1; P=0.002). The incidence with combination therapy was also lower than that with azithromycin (48%), for a risk difference of −14.8 percentage points (95% CI, −23.1 to −6.5; P<0.001). No significant difference was seen between the
azithromycin and doxycycline groups (risk difference, 1.5 percentage points; 95% CI, −7.0 to 10.0; P=0.73). The results in the per-protocol analysis were similar to those in the primary analysis. Adverse events and 28-day mortality were similar in the three groups.
CONCLUSIONS: Combination therapy with intravenous doxycycline and azithromycin was a better
therapeutic option for the treatment of severe scrub typhus than monotherapy with either drug alone. (Funded by the India Alliance and Wellcome Trust; INTREST Clinical Trials Registry–India number, CTRI/2018/08/015159.
Descriptive epidemiology of somatising tendency: findings from the CUPID study.
Somatising tendency, defined as a predisposition to worry about common somatic symptoms, is importantly associated with various aspects of health and health-related behaviour, including musculoskeletal pain and associated disability. To explore its epidemiological characteristics, and how it can be specified most efficiently, we analysed data from an international longitudinal study. A baseline questionnaire, which included questions from the Brief Symptom Inventory about seven common symptoms, was completed by 12,072 participants aged 20-59 from 46 occupational groups in 18 countries (response rate 70%). The seven symptoms were all mutually associated (odds ratios for pairwise associations 3.4 to 9.3), and each contributed to a measure of somatising tendency that exhibited an exposure-response relationship both with multi-site pain (prevalence rate ratios up to six), and also with sickness absence for non-musculoskeletal reasons. In most participants, the level of somatising tendency was little changed when reassessed after a mean interval of 14 months (75% having a change of 0 or 1 in their symptom count), although the specific symptoms reported at follow-up often differed from those at baseline. Somatising tendency was more common in women than men, especially at older ages, and varied markedly across the 46 occupational groups studied, with higher rates in South and Central America. It was weakly associated with smoking, but not with level of education. Our study supports the use of questions from the Brief Symptom Inventory as a method for measuring somatising tendency, and suggests that in adults of working age, it is a fairly stable trait
Study of Anticholinergic Effect of Moringa Pterygosperma Leaves Extract on Intestinal Smooth Muscle in comparison with Atropine
Anticholinergics are the agent that inhibits neurotransmitter acetyl choline in the parasympathetic outflow. Moringa pterygosperma is a commonly available plant that has been used commercially for its anticholinergic property. It also possesses antioxidant, anti-diabetic, anti-inflammatory, anti-ulcer and hypocholesteromic properties. The aim of the study is to assess the Anticholinergic activity of ethanolic extract of Moringa pterygosperma in comparison with Atropine using in vitro experimental models. Ethanolic extract was prepared by soxhlation method. For in vitro study, isolated chick ileum was used. Chick ileum was suspended in an organ bath containing Tyrode solution at 37◦C with adequate oxygen supply. Effect of the Moringa pterygosperma extract was studied on ileum contractions induced by Acetylcholine and compared with that of atropine. Mean percentage response was calculated for ethanolic extract of Moringa pterygosperma and atropine. Ethanolic extract of Moringa pterygosperma and atropine inhibited ileum contraction induced by Acetylcholine. From this study it was concluded that Moringa pterygosperma extract have significant anticholinergic activity compared to atropine. These findings therefore raise hope for the development of a new anticholinergic drug with few side effects that may be useful in the treatment of conditions like diarrhoea, asthma, incontinence, peptic ulcer, and muscle spasms
Clinical Symptoms and Psychosocial Problems of Cancer Patients Attending Pain and Palliative Care Clinic
Abstract Palliative care is the total care which improves the quality of life of patients suffering from cancer and chronic incurable disease. Palliative care will start immediately after the detection of cancer and continue throughout the course of illness and till the end of life. This study was conducted to understand the common symptoms and psychosocial problems of cancer patients attending the pain and palliative care clinic, Medical College Hospital, Thiruvananthapuram, Kerala. A record based cross-sectional study included all new cancer patients registered in OP during Aug 1 st to Oct 31 st 2012. Incomplete records were excluded and 150 study subjects were randomly selected for analysis. Mean age of the participants was 55.8±1.36. About 57.3% were males and 42.7% were females. Among males, most common cancer was in gastrointestinal tract and lung cancer was the second commonest. Among females, cancer in breast was the most common followed by cancer in gastrointestinal tract. Regarding the symptom analysis, majority (94.7%) had pain, 48.7% had sleeplessness, 40.7% had constipation and 38% each had loss of appetite and tiredness. This study focused the need for palliative care clinic and importance of proper intervention of physical, psychological and socio-economic problems of cancer patients
Machine-Learning-Driven High-Throughput Screening of Transition-Metal Atom Intercalated g‑C<sub>3</sub>N<sub>4</sub>/MX<sub>2</sub> (M = Mo, W; X = S, Se, Te) Heterostructures for the Hydrogen Evolution Reaction
Rising global energy demand, accompanied by environmental
concerns
linked to conventional fossil fuels, necessitates a shift toward cleaner
and sustainable alternatives. This study focuses on the machine-learning
(ML)-driven high-throughput screening of transition-metal (TM) atom
intercalated g-C3N4/MX2 (M = Mo,
W; X = S, Se, Te) heterostructures to unravel the rich landscape of
possibilities for enhancing the hydrogen evolution reaction (HER)
activity. The stability of the heterostructures and the intercalation
within the substrates are verified through adhesion and binding energies,
showcasing the significant impact of chalcogenide selection on the
interaction properties. Based on hydrogen adsorption Gibbs free energy
(ΔGH) computed via density functional
theory (DFT) calculations, several ML models were evaluated, particularly
random forest regression (RFR) emerges as a robust tool in predicting
HER activity with a low mean absolute error (MAE) of 0.118 eV, thereby
paving the way for accelerated catalyst screening. The Shapley Additive
exPlanation (SHAP) analysis elucidates pivotal descriptors that influence
the HER activity, including hydrogen adsorption on the C site (HC), MX layer (HMX), S site (HS), and
intercalation of TM atoms at the N site (IN). Overall,
our integrated approach utilizing DFT and ML effectively identifies
hydrogen adsorption on the N site (site-3) of g-C3N4 as a pivotal active site, showcasing exceptional HER activity
in heterostructures intercalated with Sc and Ti, underscoring their
potential for advancing catalytic performance
The association between supportive high school environments and depressive symptoms and suicidality among sexual minority students.
The purpose of this study was to determine if sexual minority students in supportive school environments experienced fewer depressive symptoms and lower rates of suicide ideation, plans and attempts (“suicidality”) than sexual minority students in less supportive school environments. In 2007, a nationally representative sample (N = 9,056) of students from 96 high schools in New Zealand used Internet tablets to complete a health and well-being survey that included questions on sexual attractions, depressive symptoms, and suicidality. Students reported their experience of supportive environments at school and gay, lesbian, bisexual, and transgender (GLBT) bullying, and these items were aggregated to the school level. Teachers (n = 2,901) from participating schools completed questionnaires on aspects of school climate, which included how supportive their schools were toward sexual minority students. Multilevel models were used to estimate school effects on depressive symptoms and suicidality controlling for background characteristics of students. Sexual minority students were more likely to report higher levels of depressive symptoms and suicidality than their opposite-sex attracted peers (p < .001). Teacher reports of more supportive school environments for GLBT students were associated with fewer depressive symptoms among male sexual minority students (p = .006) but not for female sexual minority students (p = .09). Likewise in schools where students reported a more supportive school environment, male sexual minority students reported fewer depressive symptoms (p = .006) and less suicidality (p < .001) than in schools where students reported less favorable school climates. These results suggest that schools play an important role in providing safe and supportive environments for male sexual minority students
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A practical comparison of group-sequential and adaptive designs
Sequential methods provide a formal framework by which clinical trial data can be monitored as they accumulate. The results from interim analyses can be used either to modify the design of the remainder of the trial or to stop the trial as soon as sufficient evidence of either the presence or absence of a treatment effect is available. The circumstances under which the trial will be stopped with a claim of superiority for the experimental treatment, must, however, be determined in advance so as to control the overall type I error rate. One approach to calculating the stopping rule is the group-sequential method. A relatively recent alternative to group-sequential approaches is the adaptive design method. This latter approach provides considerable flexibility in changes to the design of a clinical trial at an interim point. However, a criticism is that the method by which evidence from different parts of the trial is combined means that a final comparison of treatments is not based on a sufficient statistic for the treatment difference, suggesting that the method may lack power.
The aim of this paper is to compare two adaptive design approaches with the group-sequential approach. We first compare the form of the stopping boundaries obtained using the different methods. We then focus on a comparison of the power of the different trials when they are designed so as to be as similar as possible. We conclude that all methods acceptably control type I error rate and power when the sample size is modified based on a variance estimate, provided no interim analysis is so small that the asymptotic properties of the test statistic no longer hold. In the latter case, the group-sequential approach is to be preferred. Provided that asymptotic assumptions hold, the adaptive design approaches control the type I error rate even if the sample size is adjusted on the basis of an estimate of the treatment effect, showing that the adaptive designs allow more modifications than the group-sequential method