1,389 research outputs found
Chemical Constituents of Micromelum Minutum and Acronychia Laurifolia (Rutaceae)
A chemotaxonomic investigationon the leaves and stems of
Micromelum minutum (Rutaceae), has resulted in the isolation of six
components. The structure of these compounds was elucidated by means of
spectroscopic methods including by the extensive used of various NMR
techniques and al so comparison with previous studies. The use of High Field
NMR is essential in structural determination of these complex molecules. With
the aids of various NMR experimental techniques and other spectroscopic
methods such as MS, UV and JR, the correct structures of the pure isolated
compounds were established.
M.minutum collected from Kelantan yielded two novel coumarins,
microminutinin and 6-methoxymicromi nutinin, and a known coumann, scopoletin. From another separate collection of the plant from Pahang, a novel
compound, MM5, squalene, and two known coumarin, micromelin and
scopoletin have al so been isolated. A similar study on the leaves and stems of
Acronychia laurifolia collected from Pulau Singa Besar, Langkawi Island
afforded three compounds, sitosterol, seselin and an unidentified compound
Venn Diagram Multi-label Class Interpretation of Diabetic Foot Ulcer with Color and Sharpness Enhancement
DFU is a severe complication of diabetes that can lead to amputation of the
lower limb if not treated properly. Inspired by the 2021 Diabetic Foot Ulcer
Grand Challenge, researchers designed automated multi-class classification of
DFU, including infection, ischaemia, both of these conditions, and none of
these conditions. However, it remains a challenge as classification accuracy is
still not satisfactory. This paper proposes a Venn Diagram interpretation of
multi-label CNN-based method, utilizing different image enhancement strategies,
to improve the multi-class DFU classification. We propose to reduce the four
classes into two since both class wounds can be interpreted as the simultaneous
occurrence of infection and ischaemia and none class wounds as the absence of
infection and ischaemia. We introduce a novel Venn Diagram representation block
in the classifier to interpret all four classes from these two classes. To make
our model more resilient, we propose enhancing the perceptual quality of DFU
images, particularly blurry or inconsistently lit DFU images, by performing
color and sharpness enhancements on them. We also employ a fine-tuned
optimization technique, adaptive sharpness aware minimization, to improve the
CNN model generalization performance. The proposed method is evaluated on the
test dataset of DFUC2021, containing 5,734 images and the results are compared
with the top-3 winning entries of DFUC2021. Our proposed approach outperforms
these existing approaches and achieves Macro-Average F1, Recall and Precision
scores of 0.6592, 0.6593, and 0.6652, respectively.Additionally, We perform
ablation studies and image quality measurements to further interpret our
proposed method. This proposed method will benefit patients with DFUs since it
tackles the inconsistencies in captured images and can be employed for a more
robust remote DFU wound classification.Comment: 12 Pages, 7 Figure
Mercury in zooplankton from the Malacca Straits.
Total mercury concentration in mixed zooplankton was determined from near surface waters in Malacca Straits (05o 59' N, 99o 59' E and 01o 10' N, 103° 29' E). Total mercury concentrations in mixed zooplankton ranged from 1.12 to 4.68 ng dry weight g-1 with a mean of 2.08 ± 0.25 ng dry weight g-1 and showed a decreasing trend from nearshore to offshore areas. Higher mercury concentrations were found in nearshore waters (mean of 2.79 ± 0.49 ng dry weight g-1). Total mercury content was higher in the southern part of the Straits compared to the other parts. The zooplankton in the Malacca Straits environment is not heavily contaminated with mercury
Advances in solid-catalytic and non-catalytic technologies for biodiesel production
The insecure supply of fossil fuel coerces the scientific society to keep a vision to boost investments in the renewable energy sector. Among the many renewable fuels currently available around the world, biodiesel offers an immediate impact in our energy. In fact, a huge interest in related research indicates a promising future for the biodiesel technology. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The number of well-defined catalyst complexes that are able to catalyze transesterification reactions efficiently has been significantly expanded in recent years. The activity of catalysts, specifically in application to solid acid/base catalyst in transesterification reaction depends on their structure, strength of basicity/acidity, surface area as well as the stability of catalyst. There are various process intensification technologies based on the use of alternate energy sources such as ultrasound and microwave. The latest advances in research and development related to biodiesel production is represented by non-catalytic supercritical method and focussed exclusively on these processes as forthcoming transesterification processes. The latest developments in this field featuring highly active catalyst complexes are outlined in this review. The knowledge of more extensive research on advances in biofuels will allow a deeper insight into the mechanism of these technologies toward meeting the critical energy challenges in future
A Multi-scale Learning of Data-driven and Anatomically Constrained Image Registration for Adult and Fetal Echo Images
Temporal echo image registration is a basis for clinical quantifications such
as cardiac motion estimation, myocardial strain assessments, and stroke volume
quantifications. Deep learning image registration (DLIR) is consistently
accurate, requires less computing effort, and has shown encouraging results in
earlier applications. However, we propose that a greater focus on the warped
moving image's anatomic plausibility and image quality can support robust DLIR
performance. Further, past implementations have focused on adult echo, and
there is an absence of DLIR implementations for fetal echo. We propose a
framework combining three strategies for DLIR for both fetal and adult echo:
(1) an anatomic shape-encoded loss to preserve physiological myocardial and
left ventricular anatomical topologies in warped images; (2) a data-driven loss
that is trained adversarially to preserve good image texture features in warped
images; and (3) a multi-scale training scheme of a data-driven and anatomically
constrained algorithm to improve accuracy. Our experiments show that the
shape-encoded loss and the data-driven adversarial loss are strongly correlated
to good anatomical topology and image textures, respectively. They improve
different aspects of registration performance in a non-overlapping way,
justifying their combination. We show that these strategies can provide
excellent registration results in both adult and fetal echo using the publicly
available CAMUS adult echo dataset and our private multi-demographic fetal echo
dataset, despite fundamental distinctions between adult and fetal echo images.
Our approach also outperforms traditional non-DL gold standard registration
approaches, including Optical Flow and Elastix. Registration improvements could
also be translated to more accurate and precise clinical quantification of
cardiac ejection fraction, demonstrating a potential for translation
Perceptions toward Music Education
Music education in Malaysia has been through various stages of development that finally got its recognition in formal education in public schools in Malaysia. The purpose of this study is to identify the perceptions of the community towards music education. Over the years, the curriculum in Malaysia has changed where music is a component in arts education and takes only 30 minutes from the one-hour slots in the primary schools. This circumstance has impacted the teaching and learning of music in schools and further impacted the intake of students and music education at the tertiary level. In addition to this circumstance, it will also affect the community. Therefore, this study has been conducted by reviewing three videos of people's perceptions of music education. On the ground of this, this study focused on a qualitative research method by collecting data and reviewing the data from the videos chosen.
Keywords: music education; music learning; qualitative; music pedagogy
eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by E-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of AMER (Association of Malaysian Environment-Behavior Researchers), ABRA (Association of Behavioral Researchers on Asians), and cE-Bs (Centre for Environment-Behavior Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.
DOI: https://doi.org/10.21834/ebpj.v7iSI9.394
Production of biodiesel from non-edible Jatropha curcas oil via transesterification using Nd2O3-La2O3 catalyst
Biodiesel is viewed as the most promising alternative fuel to replace petroleum-based diesel since it is derived from renewable sources such as animal fats, vegetable oil and grease. Out of various vegetable oil resources for biodiesel production, Jatropha curcas oil (JCO) is a viable choice for biodiesel because it is non-edible and can be grown easily in a harsh environment. In this study, Nd2O3-La2O3 catalyst was prepared for transesterification of JCO with methanol, in order to evaluate its potential as a heterogeneous catalyst for biodiesel production. Under suitable transesterification condition at 210 °C with catalyst amount of 3 wt.%, methanol/oil molar ratio of 45 and reaction time for 4 h, the conversion of JCO to fatty acid methyl ester (FAME) achieved was more than 93% over Nd2O3-La2O3 catalyst
Parametric Study of Fire Performance of Concrete Filled Hollow Steel Section Columns with Circular and Square Cross-Section
Concrete filled hollow steel section column have been widely accepted by structural engineers and designers for high rise construction due to the benefits of combining steel and concrete. The advantages of concrete filled hollow steel section column include higher strength, ductility, energy absorption capacity, and good structural fire resistance. In this paper, comparison on the fire performance between circular and square concrete filled hollow steel section column is established. A threedimensional finite element package, ABAQUS, was used to develop the numerical model to study the temperature development, critical temperature, and fire resistance time of the selected composite columns. Based on the analysis and comparison of typical parameters, the effect of equal cross-sectional size for both steel and concrete, concrete types, and thickness of external protection on temperature distribution and structural fire behaviour of the columns are discussed. The result showed that concrete filled hollow steel section column with circular cross-section generally has higher fire resistance than the square section
Bioactive sesquiterpenes from Curcuma ochrorhiza and Curcuma heyneana
Curcuma ochrorhiza ('temu putih') and C. heyneana ('temu giring') are two Zingiberaceous species which are commonly used in traditional medicine in Malaysia and Indonesia. Phytochemical investigations on these Curcuma species have resulted in the isolation of six sesquiterpenes, namely zerumbone (1), furanodienone (2), zederone (3), oxycurcumenol epoxide (4), curcumenol (5) and isocurcumenol (6), along with phytosterols stigmasterol and alpha-sitosterol. Compounds 1 and 2 were obtained for the first time for C. ochrorhiza while 4 was new to C. heyneana. The hexane extract of C. ochrorhiza and sesquiterpenes 1 and 3 showed very strong cytotoxicity activity against T-acute lymphoblastic leukaemia cells (CEM-SS), with IC(50) values of 6.0, 0.6 and 1.6 microg mL(-1), respectively. Meanwhile, constituents from C. heyneana (4-6) demonstrated moderate inhibition against CEM-SS in cytotoxic assay, with IC(50) values of 11.9, 12.6 and 13.3 microg mL(-1), respectively. The crude extracts and sesquiterpenes isolated were moderately active against certain bacteria tested in antimicrobial screening
Assessment of clean H2 energy production from water using novel silicon photocatalyst
Nanosheets of silicon have attracted a great deal of attention due to its tunable optical and electronic properties. However, the development of facile and easily scalable synthesis process has remained a great contest. Endeavor has been made in this research to find a waste inferred effective photocatalyst to deliver hydrogen (H2) through visible light responsive water splitting.
One-pot solid phase reaction was applied to synthesis catalyst and adopted ultrathin structure. The photocatalytic efficiency of catalyst was examined by XRD, XPS, and UV–VIS absorption spectra, PL, FESEM, HRTEM and EDX. The HRTEM and FESEM images revealed the interconnected nanosheets with Si having the average thickness of 5 nm and their band gaps were 2.3–2.5 eV corresponding to the absorption of visible light range. The H2 production rate on photocatalyst was originated to 3200 μmol h−1 without utilizing any conciliatory electron givers, voltage or pH alteration, which beats the Pt, Ru, Rh, Pd and Au stacked photocatalyst ever detailed up until this point. The significant increase in photocatalytic activity could be the fast charge migration and separation from the silicon-hydrogen and silicon-hydroxyl bonds on Si surface and facilitation of charge separation could results from the multiple reflections of visible light on ultrathin nanosheets. It has been confirmed that the electron/hole recombination rate in ultrathin nanosheets of Si declined due to the oxidation of Si surface. It would be presumed that the approach of surface chemistry of silicon could not be limited towards the photocatalytic water splitting and could be applicable to remedy water pollution
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