A visible light-based photocatalyst system “green” solution for treating organic pollutants and microbes has been studied as a possible solution because it is cheap, can be recycled, and works very ...well. This study synthesized the n–px.0ZnO/ZnCo2O4 (x = weight ratio of ZnO/ZnCo2O4) heterostructure by co-precipitation method combined ultrasonic and tested its degradation of methylene blue (MB) and antibacterial activity. The structure, morphology, and chemical bonds of x.0ZnO/ZnCo2O4 were tested via X-ray diffraction (XRD), Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and energy-dispersive X-ray analysis. X-ray diffraction (XRD) of the heterogeneous material x.0ZnO/ZnCo2O4 revealed only two structures: the spinel ZnCo2O4 and the ZnO hexagonal wurtzite. The absorption edge of x.0ZnO/ZC had a redshift and increased remarkable intensity absorption. The effective degradation efficiency of the ZnO/ZnCo2O4 nanocomposite was 7.0, with a degradation efficiency of 96.5% MB. Heterojunction reduces electron–hole pair recombination, forming charge densities at the n-ZnO surface or holes at p-ZnCo2O4, promoting photocatalytic activity. 7.0ZnO/ZnCo2O4 heterojunction has a photocurrent value of 4.70 µA/cm2, which is higher than 4.5 and 7.3-fold compared to ZnO and ZnCo2O4 pure and has the smallest semicircle of AC impedance spectroscopy. This study also found that the n–p heterojunction of 7.0ZnO/ZnCo2O4 could completely inactivate Escherichia coli and Staphylococcus aureus. After the photocatalytic reaction, the ZnO/ZnCo2O4 photocatalysts were reused four times, which showed that they could be used again and were stable even after being exposed to light.
Medical students are known to have higher levels of these issues than the general population but in Vietnam the effects of the pandemic on medical student mental health was not documented. To ...estimate the prevalence and identify factors associated with self-reported anxiety disorder, depression, and perception of worsening mental health among Vietnamese medical students during the COVID-19 pandemic. A cross-sectional study was conducted from April 7.sup.th to 29.sup.th, 2020. All students in Doctor of General Medicine, Doctor of Preventive Medicine, and Bachelor of Nursing tracks at Hanoi Medical University (3672 students) were invited to participate. Data were collected using an online questionnaire including demographic characteristics, Generalized Anxiety Disorder 7 items, Patient Health Questionnaire 9 items, Fear of COVID-19 scale, and question about worsening mental health status. Robust Poisson regression was used to assess the association between mental health status and associated factors. Among 1583 students (43.1% response rate), the prevalence of students screened positive for anxiety disorder was 7.3%(95%C.I.:6.0-8.7), depression was 14.5%(95%C.I.:12.8-16.3), and perceiving worsening mental health was 6.9%(95%C.I.:5.7-8.3). In multivariable regression models, significant factors associated with self-reported anxiety disorder included being male (PR = 1.99,95%C.I.:1.35-2.92), difficulty in paying for healthcare services (PR = 2.05,95%C.I.:1.39-3.01), and high level of fear of COVID-19 (Q3:PR = 2.36,95%C.I.:1.38-4.02 and Q4:PR = 4.75,95%C.I.:2.65-8.49). Significant factors associated with self-reported depression were difficulty in paying for healthcare services (PR = 1.78,95%C.I.:1.37-2.30), and high level of fear of COVID-19 (Q3:PR = 1.41,95%C.I.:1.02-1.95 and Q4:PR = 2.23,95%C.I.:1.51-3.29). Significant factors associated with perceived worsening mental health status included having clinical experience (PR = 1.83,95%C.I.:1.17-2.88) and having atypical symptoms of COVID-19 (PR = 1.96,95%C.I.:1.31-2.94). The prevalence of self-reported depression, anxiety disorder, and worsening mental health among Vietnamese students during the first wave of COVID-19 was lower than in medical students in other countries. Further investigation is needed to confirm this finding.
We study polynomial interpolation of Hermite type of holomorphic functions based on Radon projections. We give two kinds of interpolation schemes and show that the interpolation polynomials are ...continuous with respect to the angles and the distances. When the chords are suitably distributed, we prove that the interpolation polynomials converge geometrically on the closed unit disk to the functions.
AutoDock Vina (Vina) achieved a very high docking‐success rate, p^, but give a rather low correlation coefficient, R, for binding affinity with respect to experiments. This low correlation can be an ...obstacle for ranking of ligand‐binding affinity, which is the main objective of docking simulations. In this context, we evaluated the dependence of Vina R coefficient upon its empirical parameters. R is affected more by changing the gauss2 and rotation than other terms. The docking‐success rate p^ is sensitive to the alterations of the gauss1, gauss2, repulsion, and hydrogen bond parameters. Based on our benchmarks, the parameter set1 has been suggested to be the most optimal. The testing study over 800 complexes indicated that the modified Vina provided higher correlation with experiment Rset1=0.556±0.025 compared with RDefault=0.493±0.028 obtained by the original Vina and RVina1.2=0.503±0.029 by Vina version 1.2. Besides, the modified Vina can be also applied more widely, giving R≥0.500 for 32/48 targets, compared with the default package, giving R≥0.500 for 31/48 targets. In addition, validation calculations for 1036 complexes obtained from version 2019 of PDBbind refined structures showed that the set1 of parameters gave higher correlation coefficient (Rset1=0.617±0.017) than the default package (RDefault=0.543±0.020) and Vina version 1.2 (RVina1.2=0.540±0.020). The version of Vina with set1 of parameters can be downloaded at https://github.com/sontungngo/mvina. The outcomes would enhance the ranking of ligand‐binding affinity using Autodock Vina.
A new set of empirical parameters of AutoDock Vina was proposed. The accuracy of affinity prediction was significantly increased from RDefault=0.493±0.028 to Rset1=0.556±0.025 over 800 testing complexes. Over 1036 validating complexes, the proposed parameter formed Rset1=0.617±0.017, which is rigidly larger than the default package (RDefault=0.543±0.020) and Vina version 1.2 (RVina1.2=0.540±0.020).
In this work, we developed highly porous activated carbon (AC) materials with micro/meso porosity through carbonizing rice husk and treating them with K2CO3. Elemental sulfur was then loaded to the ...micropores through a solution infiltration method to form rice husk-derived activated carbon (RHAC)@S composite materials. The as-prepared RHAC@S composites with 0.25 mg cm−1 and 0.38 mg cm−1 of sulfur loading were tested as cathodes for lithium-sulfur (Li-S) batteries. The 0.25 mg cm−1 sulfur loaded sample showed an initial discharge capacity of 1080 mA h/g at a 0.1 C rate. After 50 cycles of charge/discharge tests at the current density of 0.2 C, the reversible capacity is maintained at 312 mA h/g. The RHAC material delivered a capacity of more than 300 mA h/g at a current density of 1.7 C. These results demonstrate that the RHAC porous materials are very promising as cathode materials for the development of high-performance Li-S batteries.
IntroductionGlobally, diabetic retinopathy (DR) is the leading cause of blindness in working-aged adults. Early detection and treatment of DR is essential for preventing sight loss. Services must be ...available, accessible and acceptable to patients if we are to ensure they seek such care.ObjectivesTo understand patients’ knowledge and attitudes towards laser versus antivascular endothelial growth factor (VEGF) injections to treat DR in Vietnam, and to identify factors Vietnamese ophthalmologists consider when making treatment decisions.MethodsThis is a descriptive qualitative study based on semi-structured interviews with 18 patients (12 from Ho Chi Minh City and 6 from Hanoi) plus individual interviews with 24 ophthalmologists working in eye clinics in these cities. Thematic analysis was used to analyse the data.ResultsIn total, 10/24 (41.7%) ophthalmologists were female, and their median age was 41 years (range 29–69 years). The median age of patients was 56.5 years (range 28–72 years), and 7/18 (38.9%) were female. Briefly, factors that influence DR treatment decisions for ophthalmologists are medical considerations (ie, severity of disease, benefits and risks), availability (ie, treatment and resources) and patient-related factors (ie, costs and adherence). Patient’s perceived barriers and facilitators to treatments were based on patient and family related factors (ie, treatment and transportation costs) and previous treatment experiences (ie, positive and negative). Recommendations by all participants included ensuring that both laser and anti-VEGF injections are widely available across the country and controlling costs for patients and the healthcare system.ConclusionsReducing DR treatment costs, optimising treatments options, and expanding the network of clinics offering treatment outside metropolitan areas were the main issues raised by participants. These findings can help inform policy changes in Vietnam and may be generalisable to other low-resource settings.
Diabetic eye screening programmes have been developed worldwide based on evidence that early detection and treatment of diabetic retinopathy are crucial to preventing sight loss. However, little is ...known about the decision-making processes and training needs of diabetic retinal graders, particularly in low- and middle-income countries.
To provide data for improving evidence-based diabetic retinopathy training to help novice graders process fundus images more like experts.
This is a mixed-methods qualitative study conducted in southern Vietnam and Northern Ireland. Novice diabetic retinal graders in Vietnam (n = 18) and expert graders in Northern Ireland (n = 5) were selected through a purposive sampling technique. Data were collected from 21st February to 3rd September 2019. The interviewer used neutral prompts during think-aloud sessions to encourage participants to verbalise their thought processes while grading fundus images from anonymised patients, followed by semi-structured interviews. Thematic framework analysis was used to identify themes, supported by illustrative quotes from interviews. Mann-Whitney U tests were used to compare graders' performance.
Expert graders used a more systematic approach when grading images, considered all four images per patient and used available software tools such as red-free filters prior to making a decision on management. The most challenging features for novice graders were intra-retinal microvascular abnormalities and new vessels, which were more accurately identified by experts.
Taking more time to grade fundus images and adopting a protocol-driven "checklist" approach may help novice graders to function more like experts.
Abstract
Penicillium oxalicum has been reported as a multienzyme-producing fungus and is widely used in industry due to great potential for cellulase release. Until now, there are only 10 available ...genome assemblies of P. oxalicum species deposited in the GenBank database. In this study, the genome of the I1R1 strain isolated from the root of Ixora chinensis was completely sequenced by Pacbio Sequel sequencing technology, assembled into 8 chromosomes with the genome size of 30.8 Mb, as well as a mitogenome of 26 kb. The structural and functional analyses of the I1R1 genome revealed gene model annotations encoding an enzyme set involved in significant metabolic processes, along with cytochrome P450s and secondary metabolite biosynthesis. The comparative analysis of the P. oxalicum species based on orthology and gene family duplications indicated their large and closed pan-genome of 9,500 orthologous groups. This is valuable data for future phylogenetic and population genomics studies.
Binding energy per atom (BE) of Au9M2+ clusters and AuM dimers normalized with those of Au102+ and Au2, respectively. Au9Sc2+ and Au9Ti2+ prefer the type-I (endohedral cage-like) structure, while ...Au9M2+ (M = V, Cr, Mn, Fe, Co, and Ni) favor the type-II (tetrahedral) one. Display omitted
•The structural evolution of Au9M2+ is ruled by the bond strength of AuM dimers.•The cage-like structure for M = Sc and Ti and the tetrahedral structure for heavier ones.•The exceptionally stable Au9Cr2+ is identified as a potential magnetic superatom.
Au102+ has been found very stable showing a superatomic behavior with a highly symmetrical geometry and can be considered as the smallest copy of the golden pyramid Au20. In this work, we further explore superatomic clusters as analogues of more complex molecules by doping Au102+ cluster with 3d transition metal atom. It is found that, in similarity to their sister Au19M, the structural evolution of Au9M2+ is ruled by the bond strength of AuM dimers and can be generalized into two motifs: the endohedrally doped cage-like structure for lighter dopants (M = Sc and Ti) and the slightly distorted tetrahedral structure for heavier ones. The average binding energies and dissociation energies are calculated to identify the relatively stable patterns. The molecular orbital (MO) diagram as well as the spin distribution are computed to understand the electronic structure and magnetic behavior of studied clusters. The spin magnetic moments of Au9M2+ clusters systematically vary from 0 to 5 μB, depending on the localization of unpaired 3d electrons. With a large spin magnetic moment of 5 μB, the exceptionally stable Au9Cr2+ is identified as a potential magnetic superatom and would be beneficial for further theoretical and experimental studies.
ObjectivesTo compare the accuracy of trained level 1 diabetic retinopathy (DR) graders (nurses, endocrinologists and one general practitioner), level 2 graders (midlevel ophthalmologists) and level 3 ...graders (senior ophthalmologists) in Vietnam against a reference standard from the UK and assess the impact of supplementary targeted grader training.DesignDiagnostic test accuracy study.SettingSecondary care hospitals in Southern Vietnam.ParticipantsDR training was delivered to Vietnamese graders in February 2018 by National Health Service (NHS) UK graders. Two-field retinal images (412 patient images) were graded by 14 trained graders in Vietnam between August and October 2018 and then regraded retrospectively by an NHS-certified reference standard UK optometrist (phase I). Further DR training based on phase I results was delivered to graders in November 2019. After training, a randomised subset of images from January to October 2020 (115 patient images) was graded by six of the original cohort (phase II). The reference grader regraded all images from phase I and II retrospectively in masked fashion.Primary and secondary outcome measuresSensitivity was calculated at the two different time points, and χ2 was used to test significance.ResultsIn phase I, the sensitivity for detecting any DR for all grader groups in Vietnam was low (41.8–42.2%) and improved in phase II after additional training was delivered (51.3–87.2%). The greatest improvement was seen among level 1 graders (p<0.001), and the lowest improvement was observed among level 3 graders (p=0.326). There was a statistically significant improvement in sensitivity for detecting referable DR and referable diabetic macular oedema between all grader levels. The post-training values ranged from 40.0 to 61.5% (including ungradable images) and 55.6%–90.0% (excluding ungradable images).ConclusionsThis study demonstrates that targeted training interventions can improve accuracy of DR grading. These findings have important implications for improving service delivery in DR screening programmes in low-resource settings.
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