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Introduction: Vitamin D deficiency associated with COVID-19 patients has recently garnered interest. This is likely due to the elderly population who are most commonly affected by COVID-19. In this study, we investigated the association of vitamin D levels with the clinico-demographical and laboratory characteristics of COVID-19 patients. Methods: We recruited 77 COVID-19 patients who were admitted to Hospital Pengajar Universiti Putra Malaysia (HPUPM) from January 2022 until February 2023. Their clinico-demographic data were retrieved, and serum vitamin D and C-reactive protein (CRP) immunoassays were conducted. The vitamin D levels of each patient were categorized as normal (≥50 nmol/L) or low (<50 nmol/L). Statistical comparisons of the patients’ clinico-demographic parameters with vitamin D levels were conducted. Results: In univariable analysis of categorical variables, significantly higher proportion of female COVID-19 patients presented with low serum vitamin D levels compared with male COVID-19 patients (p=0.045; 85.3% vs 65.1%). Pertaining to continuous variables, younger COVID-19 patients demonstrated significantly higher prevalence of low vitamin D levels (p=0.040; 45.58 vs 54.90 years old). COVID-19 patients with lower CRP levels also demonstrated significantly higher proportion of low vitamin D levels (p=0.046; 35.70 vs 60.92 mg/dl). These three parameters (i.e. gender, age, and CRP levels) were included in the multivariable logistic regression analysis to determine which factor(s) remained significantly associated with low vitamin D levels. All three parameters did not show significance in the multivariable analysis. Conclusion: Absence of statistical significance in the multivariable analysis indicates that the individual associations between age, gender, and CRP levels with low vitamin D levels are not independent of each other. These suggest underlying interactions between these factors that influence their relationships with vitamin D levels, and further studies are required to clarify such interactions in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Cryopreservation is used to preserve biological samples over an extended period at ultralow temperatures. This process evolved into vitrification, a more advanced and superior technology in which fluids or water molecules form a glass-like structure without forming ice crystals. Unlike fresh cells, cryopreservation is reported to reduce oocyte viability and developmental competency. This study employed two vitrification techniques, vitrification solution (VS) and Cryotop, to investigate the meiotic resumption in bovine. Oocytes were extracted from cow ovaries collected from slaughterhouses in Banting and Shah Alam, Selangor, Malaysia. The oocytes were grouped (A, B, and B') based on cumulus morphology and matured in vitro in a culture dish (humidified 5% carbon dioxide incubator at 38.5°C) for 20 to 24 hr. Oocytes were vitrified after maturation using straws or aids of Cryotop sheets, then submerged in liquid nitrogen and stored for five days before defrosting for cryoprotectant elimination. By using Giemsa staining, the maturation state of fresh and vitrified bovine oocytes was evaluated through five parameters: zygotene, pachytene, diakinesis, metaphase I, and metaphase II. The maturation rate demonstrated only slight differences in the three groups of oocytes treated with VS (A: 44.79%; B: 30.97%; B': 20.70%) and Cryotop (A: 39.42%; B: 37.27%; B': 28.97%), which were significantly lower than fresh oocytes (A: 55.83%; B: 44.82%; B': 56.17%). Both VS and Cryotop methods were viable options for cryopreserving oocytes, but the Cryotop technique was more effective in increasing the meiotic competence of poor-quality oocytes. [ABSTRACT FROM AUTHOR]

A fuzzy linguistic data set that is uncertain is difficult to analyze and describe in the form of a smooth and continuous generic figure. Therefore, the study aims to develop a new model of a B-spline surface using a different approach of a crisp and fuzzy linguistic point relation with three types of linguistic function: low L , medium M i and high H. These linguistic functions are defined first to introduce the fuzzy linguistic point relation. Then, a new algorithm of the fuzzy linguistic bicubic B-spline surface model is presented to convert fuzzy linguistic data into fuzzy linguistic control points. In addition, a numerical example of fuzzy linguistic data is considered at the end of this study to visualize the suggested model. Thus, the relation between the fuzzy linguistic data points can be analyzed to present another area of knowledge in which symmetry phenomena occur. The symmetry here plays an important role in solving the uncertain fuzzy linguistic data problem by using the suggested model. [ABSTRACT FROM AUTHOR]

Introduction: Despite improvements in insertion techniques and catheter designs, catheter malfunction and infection pose a great source of morbidity and limitation to adequate dialysis. The two most used peritoneal dialysis (PD) catheters are the coiled and straight PD catheters. Existing studies show conflicting results. Methods: This study aims to look at the clinical outcomes and mortality between the two catheter types. This study was designed as an ambidirectional cohort study. A total of 126 patients undergoing PD, with 75 receiving the straight PD catheter and 51 receiving the coiled PD catheter, participated in the study. The primary outcome was catheter survival, and the secondary outcomes included PD failure, catheter-related infections, and all-cause mortality. Results: In the coiled catheter group, 30 (40%) patients had catheter malfunction, whereas the straight catheter group had 15 (29.4%) patients catheter malfunction. However, the survival functions represented by the Kaplan--Meier survival curve did not show any statistical significance (P = 0.659). In the coiled PD catheter group, 13 (17.3%) had PD failure, which was comparable with the straight PD catheter group of nine (17.6%) cases (P = 1.000). The catheter-related infections are similar in both groups. The mortality between two groups was also similar (P = 0.777). Conclusions: There is no difference in outcomes between the coiled and straight PD catheters. [ABSTRACT FROM AUTHOR]

Mangrove forest is known for the important natural resources and tree species that might have medicinal and authentic values. The forest floor is expected to support high diversity of polychaetes which is important in the decomposition process. This study aimed to investigate the effect of environmental condition on the infaunal polychaetes inhabiting the forest floor in relation to the change of monsoon for dry (July), pre-monsoon (September) and monsoon (December) in 2005. Polychaeta samples were obtained by sieving the top 6cm sediment of the forest floor using a 500 microns sieve. The species, Neries unifasciata, Namalycastis indica, Capitella capita, Chone collaries, Syllis trifalcata, Ampherete agulhanis, Parasclerocheilus capensis, Potamilla reniformis and Leonates decipiens were identified which generally errant species. The temperature, dissolved oxygen, pH and salinity were significantly correlated with the monsoon season but not with the polychaetes. Density of polychaetes correlates negatively with season (r = -0.657) and TOM (-0.580) at p<0.05 as shown by the Pearson-Rank Correlation Test. The infaunal polychaetes, received less influence from the surface water thus maintained their abundance despite the changes in monsoon season. More inclusive data can be obtained through a long-term study in the area. [ABSTRACT FROM AUTHOR]

This article reports the antibiotics sensitivity and pathogenicity of Aeromonas veronii 5L isolated from diseased red hybrid tilapia. The antibiotic sensitivity of A. veronii 5L was determined towards 13 antimicrobial agents. Then, the bacterial inoculums ranging between 0 and 106 CFU/mL were used for intraperitoneal challenge in red hybrid tilapia juveniles. Aeromonas veronii 5L showed resistance to ampicillin, streptomycin and sulfamethoxazole/trimethoprim. Following intraperitoneal exposure, mortality was observed as early as 24 h post infection leading to a total of 56.7% cumulative mortality at 10² CFU/mL, and 66.7% from 10³ to 106 CFU/mL. Clinical signs and gross lesions including abdominal distension, detachment of scales and ulceration on the body surface, inflammation around the operculum and based of fins, hemorrhage of internal organs, and accumulation of fluid in abdominal cavity. Histopathological examinations revealed generalized congestion of the brain, necrotic hepatocytes, generalized tubular necrosis of kidney and multifocal necrosis of spleen with splenic infarction. The LD50- 336h of A. veronii 5L was determined at 1.9 × 103.73 CFU/mL. This study revealed the capability of A. veronii as another important pathogen in tilapia culture in Malaysia. [ABSTRACT FROM AUTHOR]

The RECOVERY trial showed evidence that dexamethasone given at moderate doses for a short period of time reduced mortality in comparison to standard of care in hospitalised COVID-19 patients. However, there is no evidence to demonstrate whether higher doses of steroid may improve or worsen the outcomes. This study compares the effectiveness of low-dose- methylprednisolone to pulse-methylprednisolone among the critically-ill COVID- 19 patients. This is a retrospective observational study among critically-ill COVID- 19 patients whom were admitted to intensive care unit Hospital Pulau Pinang from August 2020 until February 2021. We collected the data of patients that received either methylprednisolone dose more than 2mg/kg/day or methylprednisolone dose equal or less than 2mg/kg/day. Both groups received standard of care. The primary outcome is all-cause mortality within 30 days from symptoms onset. The secondary outcomes are duration of mechanical ventilation, length of ICU stays and rate of complications such as acute kidney injury, sepsis, bleeding tendency and diabetic ketoacidosis. A total of 100 patients were included in the analysis, whom 64% were male, mean age of 56.6 (SD 13.4) and 53% have at least one comorbidity. The survival analysis revealed that 30 days survival rate were 91.2% in the low-dose- methylprednisolone group and 81.8% in the pulse-methylprednisolone group (p = 0.226) and showed no significant differences after adjustment for covariates such as the doses of methylprednisolone, gender, requirement of mechanical ventilation and absence or presence of comorbidity. However, age more than 60 years old does increase the risk of mortality (p value 0.018). Comparing the low- dose-methylprednisolone to pulse-methylprednisolone, the duration of mechanical ventilation were 15.7 days vs 13.8 days (p 0.572), length of ICU stay were 14.9 days vs 15 days (p 0.875) and rate of complications were not significantly differences. The use of pulse-methylprednisolone in critically-ill COVID-19 patients does not improve the survival rate. [ABSTRACT FROM AUTHOR]

Background: Preoperative anxiety is a challenging issue among patients awaiting surgical procedures. Preoperative anxiety is derived from stress responses towards perceived threat and risk related to surgery. The purpose of this study is to investigate factors that impact preoperative anxiety among surgical patients at a public hospital in Selangor, Malaysia. Method: A cross-sectional study with universal sampling was used in this study. A total of 98 preoperative patients from a public hospital in Selangor were selected to participate in a self-administered questionnaire carried out from June until October 2018. The study instrument used in this study was adapted from the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The data obtained were analyzed by descriptive analysis using frequencies and percentages. Results: Our findings showed that of the 98 respondents in this study, 57(58.2%) respondents experienced preoperative anxiety while 41(41.8%) experienced no anxiety prior to surgery. The two most common reasons for anxiety were over the outcome of their operation (51.0%) and postoperative pain (49.0%), while insufficient attention from caregiver (5.1%) was the factor with the least impact on preoperative anxiety in this study. Conclusion: The majority of respondents experienced preoperative anxiety prior to surgery. Hence, intervention should be conducted by healthcare providers, especially nurses, to reduce such distress among surgical patients at public hospitals. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is a silent disease. Most CKD patients are unaware of their condition during the early stages of the disease which poses a challenge for healthcare professionals to institute treatment or start prevention. The trouble with the diagnosis of CKD is that in most parts of the world, it is still diagnosed based on measurements of serum creatinine and corresponding calculations of eGFR. There are controversies with the current staging system, especially in the methodology to diagnose and prognosticate CKD. The aim of this review is to examine studies that focused on the different types of samples which may serve as a good and promising biomarker for early diagnosis of CKD or to detect rapidly declining renal function among CKD patient. The review of international literature was made on paper and electronic databases Nature, PubMed, Springer Link and Science Direct. The Scopus index was used to verify the scientific relevance of the papers. Publications were selected based on the inclusion and exclusion criteria. 63 publications were found to be compatible with the study objectives. Several biomarkers of interest with different sample types were taken for comparison. Biomarkers from urine samples yield more significant outcome as compare to biomarkers from blood samples. But, validation and confirmation with a different type of study designed on a larger population is needed. More comparison studies on different types of samples are needed to further illuminate which biomarker is the better tool for the diagnosis and prognosis of CKD. • Traditional markers are insensitive, over-reliance and lead to extensive time lapses. • Some reviewed biomarkers showed great promise but further validation is required. • Urine is a good and easier sample for clinical diagnosis as compared to blood. • Urine and blood have their own advantages and disadvantages in CKD diagnosis. [ABSTRACT FROM AUTHOR]

Context. The open cluster (OC) NGC 2453 is of particular importance since it has been considered to host the planetary nebula (PN) NGC 2452, however their distances and radial velocities are strongly contested. Aims. In order to obtain a complete picture of the fundamental parameters of the OC NGC 2453, 11 potential members were studied. The results allowed us to resolve the PN NGC 2452 membership debate. Methods. Radial velocities for the 11 stars in NGC 2453 and the PN were measured and matched with Gaia data release 2 (DR2) to estimate the cluster distance. In addition, we used deep multi-band UBVRI photometry to get fundamental parameters of the cluster via isochrone fitting on the most likely cluster members, reducing inaccuracies due to field stars. Results. The distance of the OC NGC 2453 (4.7 ± 0.2 kpc) was obtained with an independent method solving the discrepancy reported in the literature. This result is in good agreement with an isochrone fitting of 40–50 Myr. On the other hand, the radial velocity of NGC 2453 (78 ± 3 km s−1) disagrees with the velocity of NGC 2452 (62 ± 2 km s−1). Our results show that the PN is a foreground object in the line of sight. Conclusions. Due to the discrepancies found in the parameters studied, we conclude that the PN NGC 2452 is not a member of the OC NGC 2453. [ABSTRACT FROM AUTHOR]

Cinnamon nanoparticles (CNPs) containing rich active agents of cinnamaldehyde and polyphenols are prospective for nanobiomedicine. They are preferred over metallic nanoparticles due to excellent bioactivity and non-toxicity. This paper reports the structural and emission properties of CNPs grown in citric acid medium (under varying laser energy) using pulse laser ablation in liquid (PLAL) technique. TEM analysis revealed the nucleation of crystalline truncated tetrahedral CNPs with average diameter ≈12.85 nm. EDX spectra detected the exact elemental constituents in protein capped CNPs. Raman spectra displayed the symmetric bonding vibration of CNPs in the presence of secondary metabolites enclosing terpenoids, flavonoids, phenols and tannins. Photoluminescence emission spectra disclosed two prominent peaks centered at 420 nm and 480 nm assigned to the occurrence of phenolic acids in CNPs. [ABSTRACT FROM AUTHOR]

Aluminum (Al) and Gallium (Ga) co-doped ZnO nanostructures (AGZO NSs) were prepared on p-type Si(100) substrate using sol-gel united spin coating method. Ga contents were varied from 1 to 5 at% at fixed Al doping (1 at%). Synthesized samples were annealed at 500 °C for 3 h. The structural, morphological, and electrical property of the optimum sample (containing 3 at% of Ga) were determined. Optimum AGZO NSs enclosing highest density of nanorod (NR) arrays were selected to fabricate a hydrogen gas (H 2 ) sensor. As-grown AGZO NSs revealed hexagonal wurtzite structure with mean grain size ≈ 41.20 nm and resistivity ≈ 0.6475 × 10 −2 Ω cm. The gas sensing attributes of the developed sensor was evaluated for two different temperatures (at 100 and 150 °C) under varying gas H 2 contents (from 250 to 1750 ppm). Furthermore, the selectivity of the AGZO NSs for three different gases such as H 2 , CO and CH 4 were examined. The sensitivity of the sensor at 100 °C was augmented sharply from 60% to 385% with the increment of H 2 gas contents from 250 to 1750 ppm. This enhancement was attributed to the increases of hydrogen gas current (I H ) and good stability of the air atmosphere. The synthesized AGZO NSs have high potential for gas sensing, photovoltaic and field emission applications. [ABSTRACT FROM AUTHOR]

Organic nanoparticles with controlled properties are advantageous for diversified biomedical and pharmacological applications. Cinnamon nanoparticles (CNPs) being bioactive and nontoxic can be effective antibacterial agents. Driven by this idea, we prepared spherical CNPs using pulse laser ablation in liquid (PLAL) technique and characterized these NPs. A pure cinnamon target immersed in liquid ethanol (5 mL) was ablated using Q-switched Nd:YAG pulse laser of varying energy (30–180 mJ). Laser energy dependent structure, morphology and optical properties of the as-grown CNPs were determined. Furthermore, the antibacterial activity of such CNPs against four bacterial strains ( Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa ) was evaluated using agar well diffusion and optical density measurements. These CNPs were demonstrated to be beneficial for the development of antibacterial drugs and food processing. [ABSTRACT FROM AUTHOR]

The influence of annealing time on the structure, morphology and photoluminescence behavior (Al)/(Ga) co-doped ZnO (AGZO). nanofilms are grown on the p-type Si(100) substrate via combined sol-gel, spin coating annealed in air at 500 °C at 0–3 h. Samples are characterized using XRD, TEM, AFM, FESEM, EDX, (PL) and Raman measurements. XRD pattern confirmed the growth of highly poly-crystalline hexagonal wurtzite structure of ZnO with preferred orientation along (101) direction. At (3 h) is found to cause lattice contraction and strain relaxation. TEM images revealed the nucleation of nanoparticles (NPs) and SAED pattern identified the lattice parameter. Raman spectra of AGZO exhibited optical and acoustic modes. FESEM displayed an increase in the particles size and number of nanoflakes with increasing annealing time. EDX detected right elemental traces. PL revealed an intense emission peak centered at 3.23 eV, which is continuously shifted toward lower frequency with increasing time. [ABSTRACT FROM AUTHOR]

Broad range of biomedical applications demands accurate synthesis and characterization of various nanoparticles. We report the characterization of cinnamon nanoparticles (CNPs) grown via simple pulsed laser ablation in liquid (PLAL). The influence of different liquid media (olive oil, ethanol, and citric acid each of volume 4 ml) on the growth morphology, structure and optical properties of CNPs is determined. Q-switched 1064-Nd: YAG laser of 10 ns pulse duration, 1 Hz repetition rate, 532 nm s harmonic generation and laser fluence of 6.37 J/cm 2 is used to irradiate the cinnamon targets immersed in those liquids. Samples are characterized using TEM, HRTEM, SAED, FTIR, UV–Vis and Photoluminescence measurements. TEM images revealed the nucleation of CNPs of average size 18.36 nm (in olive oil), 21.48 nm (in ethanol), and 29.56 nm (in citric acid). Morphology of CNPs is demonstrated to be sensitive to the liquid medium. Our simple and innovative method may constitute a basis to produce CNPs of desired size distribution potential for the development of nanobiomedicine. [ABSTRACT FROM AUTHOR]

The objective of green tax law is to promote green growth among companies, people and communities as well as environmental preservation. The Malaysian green tax law, however, is more concerned with tax incentives than with tax penalties. Evidence showed most companies in Malaysia are not even aware of the incentive-based tax and thus, do not include them as part of their strategies for environmental sustainability. The green tax penalty has become a popular environmental policy tool for many countries, but not in Malaysia. The Malaysian system of environmental taxes should include the green tax penalty. Therefore, this study aims to identify key drivers for companies to respond to the green tax policy. The study uses institutional theory to explore the driving force of green tax acceptance within companies. Institutional pressure suggests that the three mechanisms of organisational changes are coercive, mimetic, and normative pressures. Coercive pressure stems from political influences and the legitimacy problem; mimetic pressure results from a standard response to uncertainty, and normative pressure is associated with professionalisation. The study utilises the survey questionnaire to identify opinions, experiences and behaviours towards green tax acceptance among manufacturing companies. The population of the study is manufacturing companies and the unit of analysis is managers or accountants who represent the manufacturing companies and members of the Federation of Malaysian Manufacturer (FMM). The outcomes from the study confirmed the institutional theory to support the green tax reform acceptance for companies in Malaysia. The study also develops a green tax model that the government can take into account when enacting green tax reform so that companies can cooperate with Malaysia's green tax law. The study contributes to institutional theory by conceptualising the key drivers of green tax laws among Malaysian companies. The conceptualisation is used to formulate a structural model that explains the key drivers of green tax laws, and the structural model is tested against empirical data. A better understanding of factors influencing green tax policy acceptance is relevant to the government to strengthen the green growth environment and enhance awareness to create a shared responsibility among Malaysian companies. [ABSTRACT FROM AUTHOR]

Natural cinnamon containing polyphenolic compound is well known for diverse biological activities, broad range of pharmacological and therapeutic properties. However, the potential of nanocinnamon for antibacterial usage was not widely explored. Highly crystalline elliptical shaped cinnamon nanoparticles (CNPs) were prepared via pulse laser ablation in liquid (PLAL) by immersing a cinnamon target in methanol. Effects of varying laser fluence on the structure, morphology and optical properties of as-grown CNPs were determined. Samples were characterized via UV-Vis, FTIR, XRD, TEM, HRTEM, SAED, EDX, DLS and HPLC measurements. Methanol was found to be favorable for the growth of CNPs at optimum fluence of 5.73 J/cm 2 . These CNPs revealed robust antibacterial activity against Gram-negative and Gram-positive bacterial strains including Escherichia coli , Pseudomonas aeruginosa , Bacillus subtilis and Staphylococcus aureus . Antibacterial activity of CNPs was evaluated via agar well diffusion assay and optical density (OD 600 ) tests. It was established that the PLAL may constitute a basis for the production CNPs with desired size distribution potential for nanomedicinal applications. [ABSTRACT FROM AUTHOR]

Exploration of novel meso-materials with higher surface areas is a major challenge in the rapidly expanding field of opto-chemical sensor devices. Therefore, synthesis and growth mechanism of surfactant CTAB assisted sol-gel based silica and phenolphthalein encapsulated silica nanoparticles (NPs) and their optical and pH sensing activities is reported at low temperature in this present communication. Hierarchical/ordered structures/architectures are observed after encapsulation of phenolphthalein by FE-SEM analysis. AFM analysis exhibits the formation of porous nanostructures with average surface roughness Ra ∼5.15 nm which is reduced to Ra ∼4.98 nm after encapsulation of phenolphthalein, whereas, particle size increased from 8 nm to 13 nm. N 2 adsorption isotherms explain the meso-porous nature of the matrix with high surface area value of 443 m 2 /g with a pore volume of 0.93 cm 3 /g and pore diameter of 85.59 Å. Experimental findings show that the prepared meso-silica-phenolphthalein frameworks have high thermal stability, low refractive index (1.33) with good optical transparency of 83%. Furthermore, the evanescent wave is used to selectively excite the phph molecules encapsulated in silica matrix and deposited on the Plastic Clad Silica fiber as cladding for sampling the aqueous media (pH solutions 2–12) surrounding the fiber. Highest sensing response is optimized for pH 12 within 1s with pink color indication. The improved structural and optical characteristics identify that the prepared optochemical nanosensor device has potential for fast detection of pH at dynamic range. [ABSTRACT FROM AUTHOR]

Hydrogen production via water electrolysis was studied under the effect of magnetic and optical field. A diode solid state laser at blue, green and red were utilized as optical field source. Magnetic bar was employed as external magnetic field. The green laser has shown a greatest effect in hydrogen production due to its non-absorbance properties in the water. Thus its intensity of electrical field is high enough to dissociation of hydronium and hydroxide ions during orientation toward polarization of water. The potential to break the autoprotolysis and generate the auto-ionization is the mechanism of optical field to reveal the hydrogen production in water electrolysis. The magnetic field effect is more dominant to enhance the hydrogen production. The diamagnetic property of water has repelled the present of magnetic in water. Consequently the water splitting occurs due to the repulsive force induced by the external magnetic field. The magnetic distributed more homogenous in the water to involve more density of water molecule. As a result hydrogen production due to magnetic field is higher in comparison to optical field. However the combination both fields have generated superior effect whereby the hydrogen yields nine times higher in comparison to conventional water electrolysis. [ABSTRACT FROM AUTHOR]

Despite their close proximity, the complex interplay between the two Magellanic Clouds, the Milky Way and the resulting tidal features, is still poorly understood. Recent studies have shown that the Large Magellanic Cloud (LMC) has a very extended disc strikingly perturbed in its outskirts. We search for recent star formation in the far outskirts of the LMC, out to ~30° from its centre. We have collected intermediate-resolution spectra of 31 young star candidates in the periphery of the LMC and measured their radial velocity, stellar parameters, distance and age. Our measurements confirm membership to the LMC of six targets, for which the radial velocity and distance values match well with those of the Cloud. These objects are all young (10-50 Myr), main-sequence stars, projected between 7° and 13° from the centre of the parent galaxy. We compare the velocities of our stars with those of a disc model, and find that our stars have low to moderate velocity differences with the disc model predictions, indicating that they were formed in situ. Our study demonstrates that recent star formation occurred in the far periphery of the LMC, where thus far only old objects were known. The spatial configuration of these newly formed stars appears ring-like with a radius of 12 kpc and a displacement of 2.6 kpc from the LMC's centre. This structure, if real, would be suggestive of a star formation episode triggered by an off-centre collision between the Small Magellanic Cloud and the LMC's disc. [ABSTRACT FROM AUTHOR]

Despite their close proximity, the complex interplay between the two Magellanic Clouds, the Milky Way and the resulting tidal features, is still poorly understood. Recent studies have shown that the Large Magellanic Cloud (LMC) has a very extended disc strikingly perturbed in its outskirts.We search for recent star formation in the far outskirts of the LMC, out to ~30° from its centre.We have collected intermediate-resolution spectra of 31 young star candidates in the periphery of the LMC and measured their radial velocity, stellar parameters, distance and age. Our measurements confirm membership to the LMC of six targets, for which the radial velocity and distance values match well with those of the Cloud. These objects are all young (10-50 Myr), main-sequence stars, projected between 7° and 13° from the centre of the parent galaxy. We compare the velocities of our stars with those of a disc model, and find that our stars have low to moderate velocity differences with the disc model predictions, indicating that they were formed in situ. Our study demonstrates that recent star formation occurred in the far periphery of the LMC, where thus far only old objects were known. The spatial configuration of these newly formed stars appears ring-like with a radius of 12 kpc and a displacement of 2.6 kpc from the LMC's centre. This structure, if real, would be suggestive of a star formation episode triggered by an off-centre collision between the Small Magellanic Cloud and the LMC's disc. [ABSTRACT FROM AUTHOR]

Surface modification of metals is demanding for high strength industrial purposes. Weak mechanical properties of aluminum (Al) are disadvantageous for several applications and needs improvement. We modify the surface of pure Al substrate by alloying it with a thick layer of Fe-Ni, where a low power (27 watt) cw CO 2 laser with varying exposure time (30, 40 and 50 s) is used. The exposure time dependent microstructure, surface morphology, and surface hardness of the achieved inter-metallic alloyed samples are determined. Microstructure analysis revealed the formation of different phases (Al 0.9 Ni 1.1 , AlNi 3 , Al 6 Fe, AlFe 3 , Al 5 Fe 2 and Al 76.8 Fe 14 , Al 5 FeNi) with chemical heterogeneity. Alloyed sample displayed enhanced surface hardness (varied from 27 HV 0.1 to 53.9 HV 0.1 ) for extended laser radiation exposure time (from 30 to 50 s). A new inter-metallic compound aluminum-iron-nickel (Al-Fe-Ni) with considerably tougher surface is achieved. Our observations may contribute towards the development of laser assisted modification of metal surface alloying. [ABSTRACT FROM AUTHOR]

Despite their close proximity, the complex interplay between the two Magellanic Clouds, the Milky Way and the resulting tidal features, is still poorly understood. Recent studies have shown that the Large Magellanic Cloud (LMC) has a very extended disc strikingly perturbed in its outskirts. We search for recent star formation in the far outskirts of the LMC, out to ~30° from its centre. We have collected intermediate-resolution spectra of 31 young star candidates in the periphery of the LMC and measured their radial velocity, stellar parameters, distance and age. Our measurements confirm membership to the LMC of six targets, for which the radial velocity and distance values match well with those of the Cloud. These objects are all young (10-50 Myr), main-sequence stars, projected between 7° and 13° from the centre of the parent galaxy. We compare the velocities of our stars with those of a disc model, and find that our stars have low to moderate velocity differences with the disc model predictions, indicating that they were formed in situ. Our study demonstrates that recent star formation occurred in the far periphery of the LMC, where thus far only old objects were known. The spatial configuration of these newly formed stars appears ring-like with a radius of 12 kpc and a displacement of 2.6 kpc from the LMC's centre. This structure, if real, would be suggestive of a star formation episode triggered by an off-centre collision between the Small Magellanic Cloud and the LMC's disc. [ABSTRACT FROM AUTHOR]

The ruminant industry is one of the most burgeoning sectors in Malaysia. With increasing beef productions in Malaysia, the issue of bacterial contamination on beef carcass deserves extra attention as to ensure public food safety. The main objective of this study was to determine the level of bacterial contamination of beef carcasses by determining the presence of selected microorganisms (total plate count, Enterobacteriaceae, Escherichia coli and Salmonella spp.). Swab samples were taken from the two abattoirs located in Selangor, Malaysia from October 2015 to February 2016. The results obtained showed that the samples (n = 40) of the two abattoirs has recorded an average reading of 4.00 ± 0.934 log CFU/cm2 for total plate count. Enterobacteriaceae was detected from 82.5% of total samples with an average reading of 2.728 ± 0.936 log CFU/cm2. While for E. coli was isolated from 55% of total samples with an average reading of 1.87 log CFU/cm2. A total of 4 samples (10%) were tested positive for the presence of Salmonella spp. The result reflect on the level of contamination of locally produced beef in Malaysian abattoirs. Thus, this study will allow better interventions from related authorities in order to improve the safety and the quality of locally produced beef. [ABSTRACT FROM AUTHOR]

Using a simple combination of pulse laser ablation in liquid and hydrothermal (PLAL-H) approaches, we control the morphology of ZnO nanostructures (ZNSs) to determine the feasibility of their photocatalytic efficacy. These ZNSs are deposited on Si (100) substrates and two different morphologies are achieved. In this synergistic approach, PLAL synthesized NSs are used as a nutrient solution with different pH for further hydrothermal treatment at 110 °C under varying growth time (5, 30 and 60 min). Surface morphology, structure, composition, and optical characteristics of the prepared ZNSs are determined using FESEM, XRD, FTIR and Photoluminescence (PL) and UV–vis absorption measurements. The morphology revealed remarkable transformation from nanorods (NRs)/nanoflowers (NFs) (at pH 7.6) to nanoparticles (NPs)-like (at pH 10.5) structure. XRD patterns showed better polycrystallinity for NPs with enlarged band gap than NR/NF-like structures. Both PL and UV–vis spectral analysis of ZNPs exhibited higher surface area and deep level defects density dependent morphology, where the nutrient pH and growth time variation are found to play a significant role towards structural evolution. Furthermore, the photocatalytic activities of, such ZNSs are evaluated via sunlight driven photo-degradation of methylene blue (MB) dye. The photocatalytic efficiency of ZNPs is demonstrated to be much superior (97.4%) than ZNRs/ZNFs-like morphology (86%). Such enhanced photocatalytic activities of as-synthesized ZNPs is attributed to the synergism of the improved surface area and defects density, which is useful for promoting the adsorption of the MB dye and suppressed surface recombination of photo-generated charge carriers. [ABSTRACT FROM AUTHOR]

We present wide-field JHKS photometry of 16 Galactic globular clusters located towards the Galactic bulge, calibrated on the Two Micron All-Sky Survey photometric system. Differential reddening corrections and statistical field star decontamination are employed for all of these clusters before fitting fiducial sequences to the cluster red giant branches (RGBs). Observed values and uncertainties are reported for several photometric features, including the magnitude of the RGB bump, tip, the horizontal branch (HB) and the slope of the upper RGB. The latest spectroscopically determined chemical abundances are used to build distance- and reddening-independent relations between observed photometric features and cluster metallicity, optimizing the sample size and metallicity baseline of these relations by supplementing our sample with results from the literature. We find that the magnitude difference between the HB and the RGB bump can be used to predict metallicities, in terms of both iron abundance [Fe/H] and global metallicity [M/H], with a precision of better than 0.1 dex in all three near-IR bandpasses for relatively metal-rich ([M/H] ≳ -1) clusters. Meanwhile, both the slope of the upper RGB and the magnitude difference between the RGB tip and bump are useful metallicity indicators over the entire sampled metallicity range (-2 ≲ [M/H] ≲ 0) with a precision of 0.2 dex or better, despite model predictions that the RGB slope may become unreliable at high (near-solar) metallicities. Our results agree with previous calibrations in light of the relevant uncertainties, and we discuss implications for clusters with controversial metallicities as well as directions for further investigation. [ABSTRACT FROM AUTHOR]

We present wide-field JHKS photometry of 16 Galactic globular clusters located towards the Galactic bulge, calibrated on the Two Micron All-Sky Survey photometric system. Differential reddening corrections and statistical field star decontamination are employed for all of these clusters before fitting fiducial sequences to the cluster red giant branches (RGBs). Observed values and uncertainties are reported for several photometric features, including the magnitude of the RGB bump, tip, the horizontal branch (HB) and the slope of the upper RGB. The latest spectroscopically determined chemical abundances are used to build distance-and reddening-independent relations between observed photometric features and cluster metallicity, optimizing the sample size and metallicity baseline of these relations by supplementing our sample with results from the literature. We find that the magnitude difference between the HB and the RGB bump can be used to predict metallicities, in terms of both iron abundance [Fe/H] and global metallicity [M/H], with a precision of better than 0.1 dex in all three near-IR bandpasses for relatively metal-rich ([M/H] ≳ -1) clusters. Meanwhile, both the slope of the upper RGB and the magnitude difference between the RGB tip and bump are useful metallicity indicators over the entire sampled metallicity range (-2 ≲ [M/H] ≲ 0) with a precision of 0.2 dex or better, despite model predictions that the RGB slope may become unreliable at high (near-solar) metallicities. Our results agree with previous calibrations in light of the relevant uncertainties, and we discuss implications for clusters with controversial metallicities as well as directions for further investigation. [ABSTRACT FROM AUTHOR]

Water electrolysis is the cleanest technology to gain energy because its combustion product is only water. However this technology still lack of efficiency due to its residue electric field effect. One way to overcome the problem is by utilizing sunlight. Three sets of experiments were conducted and found that by using collimated sunlight the hydrogen production enhance up to 53% higher in comparison to conventional light (31%) and dark field (16%). The polarizibilty and infinitival of the sunlight result in strengthening the electric field in the water electrolysis thus enrich the water splitting. The surface tension and the electrical conductivity were measured to validate the effect of hydrogen bond breaking. The stretching and stressing of the hydrogen bond in order to align the dipole of water parallel to the external electric field was manifested by the behaviour of surface tension. The large separation charges due to the water splitting were demonstrated via the increment of electrical conductivity. [ABSTRACT FROM AUTHOR]

The size distribution of gold hydrosol aggregates induced by ascorbic acid has been characterised by small angle x-ray scattering (SAXS). The results are used to compute the extinction coefficients around the localised surface plasmon resonance (LSPR) wavelengths and verified by comparing experimental extinction spectra obtained via spectrophotometry. Citrate refluxed gold nanoparticles with initial ionic ratio of 0.94 measured by fitting an averaged intensity profile from two scattering lengths exhibit lognormal distribution with mean diameter of 27.4 nm (σd = 14.4 nm), while ascorbic acid induced agglomeration on gold nanoparticles at pH of 3.2 has mean diameter of 51.2 nm (σd = 19.2 nm). Both experiment and simulated optical extinction shows agreement in LSPR peak wavelength corresponding to their respective mean particle sizes. [ABSTRACT FROM AUTHOR]

The synthesis of Ni-doped silica-titania nanocomposite is performed by sol-gel method. The samples prior and after heat treatment at 300 °C for 1 h are characterized by analytical instrumental techniques. FE-SEM and AFM results indicate the regular morphology with low surface roughness without any cracks. EDX analysis verifies the formation of nanocomposites. XRD of the films reveals crystalline titania phases after annealing at 300 °C. The FTIR confirms the bond linkage between silica, titania and nickel molecules. High surface area ~155 m/g, pore volume of 0.2 cm/g and pore diameter of 48.10 Å are obtained after heat treatment. The magnetic results show that the composite content is reminiscent of ferromagnetic hysteresis loop, with remanence magnetization Mr of 45.35 and 13.20 emu/g for both samples. The organic dye phenol red is used for the evaluation of photocatalytic activity of the synthesized magnetic material. The homogeneous surface morphology, crystalline nature, good solubility of magnetic nanoparticles into the silica-titania matrix show that the Ni/SiO-TiO magnetic photocatalyst can be efficient and reusable. [ABSTRACT FROM AUTHOR]

From 2003 to 2006, samples of intestinal content and spleens from 10-day-old to 6-week-old fattening turkeys showing clinical signs of enteritis were analyzed by specific PCR and RT-PCRs for detection of haemorrhagic enteritis virus (HEV), avian reovirus (ARV), turkey astrovirus-2 (TastV-2), and turkey coronavirus (TCV). A total of 23 flocks from 6 farms were included in the study. Specific sequence for HEV hexon gene was present in 6 samples from turkeys younger than and in one turkey at 6 weeks of age. A product of TastV-2 capsid gene was detected in 17/23 intestinal content samples. A 626-bp band of sigma A (S2) encoding gene segment from avian reovirus was present in three samples, all from the same farm. Sequence analysis of 450 bp fragment of avian reovirus sigma A encoding gene sequence showed that our strain had the identity of 91.3% with the strains 138, 2408, 1733, 919, T6, and Os161. No TCV specific PCR band was found in any sample. Four flocks were positive simultaneously for HEV and TastV-2, and three flocks on TastV-2 and ARV. Severity of poult enteritis described in our study is caused by immunosuppressive TastV-2 in combination with HEV or ARV. [ABSTRACT FROM AUTHOR]

Samples of urchin and multipods-like ZnO micro/nanostructure with various morphology, physical, and optical properties are fabricated on glass and silicon substrates through a simple hydrothermal method without any catalyst. The samples demonstrated that high-density ZnO nanorods are assembled to form ZnO micro/nanostructure which has structures that depended on growth time. The influence of growth time and substrate type on the crystalline structure, morphology, and emission response of synthesized ZnO samples were investigated. The samples were characterized by XRD, EDX, FESEM, and PL measurements. A reduction in consumed growth times to produce ZnO micro/nanostructure was achieved. XRD patterns confirmed the wurtzite hexagonal structure of ZnO micro/nanostructure with good crystallinity for (1–4 h) growth time, irrespective of substrate type. Conversely, FESEM images revealed that prolonged growth time of (6–8 h) resulted in destruction of ZnO morphology. EDX patterns showed an oxygen-deficiency- and crystal-defect-mediated growth of ZnO micro/nanostructure on both substrates with different stoichiometric ratios. Optical band-gap energy evaluated from the emission spectra displayed reasonable blue and red shifts depending on growth time (for 1–4 h) and substrate type. The formation mechanism of ZnO micro/nanostructure was demonstrated from the perspective of nucleation and self-assembly of growth unites. [ABSTRACT FROM AUTHOR]

We report the morphology-controlled ZnO nanostructures (ZNSs) evolution synthesized via a novel and facile technique at different growth times, where the pulse laser ablation in liquid (PLAL) is creatively combined with hydrothermal (H) method (hereafter called PLAL-H technique). Four types of ZNSs with varying sizes and shapes such as tapers, multipods, flowers, and hollow flowers are produced on Si substrate via PLAL-H technique. Furthermore, multipod- and flower-like ZNSs are grown using direct hydrothermal method to compare them with the one obtained via synergistic effects of PLAL-H method. This catalyst-free fabrication method is not only cost-effective but greatly useful for the rapid production of different quality of ZNSs at low temperature. ZNSs synthesized under prolonged growth time (60 min) exhibited structural deformation. Growth technique and time dependent morphology, structure, composition, and optical properties of these as-grown ZNSs are characterized using FESEM, X-ray diffraction, FTIR, photoluminescence, and UV–vis measurements. Synthesized ZNSs revealed excellent crystallinity and growth process dependent variation in the physical and optical features. The ZNSs growth mechanism is understood. Excellent features of the results demonstrate that this synergized new growth technique may constitute a basis for modifying the morphology, sizes, and optical properties of ZNSs in a controllable manner useful for diverse applications. [ABSTRACT FROM AUTHOR]

Liquid refractometer based mirrorless fiber optic displacement sensor is proposed and demonstrated. Various liquid samples with refractive index in the range of 1.333–1.433 RIU were used as modulator. The refractometer sensor was operated based on intensity modulation with regard to displacement sensor. Each of the tested samples has its own fingerprint. This allows the performance of the sensor to be quantified based on the front slope, back slope and peak voltage. The peak voltage is optimized at constant displacement of 3 mm. The sensitivity of the refractometer sensor based mirrorless fiber optic displacement sensor is achieved as 188.37 mV/mm/RIU with repeatability of 99.87% and resolution of 0.00531RIU. The sensor work based on the peak voltage. The higher the peak voltage means the higher the refractive index of the liquid medium. The collection of more lights entering into the receiver is realized due to the contribution from the reflectivity of the surface liquid. Such mirrorless liquid refractometer sensor offering many advantages including the simplicity, easier, faster and cheaper compared to conventional refractometer. [ABSTRACT FROM AUTHOR]

The performance of passively Q-switched Nd:YAG laser operating at 1060 nm is demonstrated using liquid graphene oxide (GO) composite solution as saturable absorber for the first time. The Q-switched Nd:YAG laser is pumped by a xenon flashlamp. The GO was prepared using the simplified Hummer's method and then mixed with polyethylene oxide to form a composite solution. The Q-switched pulsed laser operates at wavelength of 1064.5 nm with a threshold pump energy of 33.64 J. The maximum output Q-switched laser energy of 41.6 mJ achieved at the maximum pump energy of 81 J. The corresponding pulse width is 98.67 ns. [ABSTRACT FROM AUTHOR]

Passively Q-switched Nd:YAG laser pumped by flashlamp is demonstrated by using a saturable absorber made of a multi-walled carbon nanotubes-polyethylene oxide (MWCNTs-PEO) film. Two positions of the film are tested in the resonator to optimize its performance. The maximum pulsed energy obtained for the Q-switching operation is 1.68 mJ corresponding to 88.36 J electrical pump energy. The pulse duration of 83.64 ns is achieved with a peak power of 20.1 kW. A MWCNTs-PEO-film is a promising saturable absorber because of its simple cavity design, reliable and low cost fabrication compared to normal nonlinear crystal absorber. [ABSTRACT FROM AUTHOR]

Hydrocarbon contamination in water is a major environmental concern in terms of foreseen collapse of the natural ecosystem. Hydrocarbon level in water was determined by generating acoustic wave via an innovative laser-induced breakdown in conjunction with high-speed photographic coupling with piezoelectric transducer to trace acoustic wave propagation. A Q-switched Nd:YAG (40 mJ) was focused in cuvette-filled hydrocarbon solution at various concentrations (0–2000 ppm) to induce optical breakdown, shock wave generation and later acoustic wave propagation. A nitro-dye (ND) laser (10 mJ) was used as a flash to illuminate and frozen the acoustic wave propagation. Lasers were synchronised using a digital delay generator. The image of acoustic waves was grabbed and recorded via charged couple device (CCD) video camera at the speed of 30 frames/second with the aid of Matrox software version 9. The optical delay (0.8–10.0 μs) between the acoustic wave formation and its frozen time is recorded through photodetectors. A piezo-electric transducer (PZT) was used to trace the acoustic wave (sound signal), which cascades to a digital oscilloscope. The acoustic speed is calculated from the ratio of acoustic wave radius (1–8 mm) and optical time delay. Acoustic wave speed is found to linearly increase with hydrocarbon concentrations. The acoustic signal generation at higher hydrocarbon levels in water is attributed to supplementary mass transfer and impact on the probe. Integrated high-speed photography with transducer detection system authenticated that the signals indeed emerged from the laser-induced acoustic wave instead of photothermal processes. It is established that the acoustic wave speed in water is used as a fingerprint to detect the hydrocarbon levels. [ABSTRACT FROM AUTHOR]

The correlation between structural and optical properties of surfactant-assisted hybrid thin films deposited by sol–gel method has been studied. The samples prior and after heat treatment were characterized by analytical instrumental techniques like field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscope (TEM) and UV–vis spectroscopy. Microscopic results indicate that the inorganic nanoparticles are much smaller in the presence of surfactant than in the pure hybrid film, and the shape of the inorganic particles and compatibility with surfactant vary at a low-temperature of 100 °C. FE-SEM study confirms grain size within 12–20 nm range that exhibit regular morphology with large pores without any cracks. EDX analysis verify stoichiometric formation of nanocomposite. XRD of the films reveal amorphous to crystalline anatase titania phase after annealing at low-temperature of 100 °C. The FTIR confirms the bond linkage between silica, titania and surfactant molecules. The refractive index of 1.48, with thickness 138 nm and porosity 73% of the films are measured with spectroscopic ellipsometry. Band-gap of 3.8 eV is obtained from the absorption of UV–vis spectroscopy. UV–vis spectroscopy reveals that the prepared matrix shows good response at pH 12 with 96.19% repeatability without leaching and has potential as optochemical sensor with fast response time. [ABSTRACT FROM AUTHOR]

A two-step method was applied to obtain gold–silver alloy nanoparticles (Au–Ag alloy NPs). First, Au and Ag colloids with average particle sizes of 14.80 and 8.47 nm, respectively, were synthesized by pulsed laser ablation of pure metallic targets immersed in ethanol, subsequent mixing, and re-irradiation of individual Au and Ag colloids (volume ratio of 4:1). In this study, a dense layer of porous titanium dioxide (TiO 2 ) film with a thickness of ∼11 μm was deposited directly on the central area of the conductive face of a fluorine tin oxide (FTO) glass by blade doctor method. A specific amount of N719 dye molecules with and without the plasmonic-metal nanoparticles (NPs) was mixed, incorporated into the porous TiO 2 film, and used as photoanode to fabricate dye-sensitized solar cells (DSSCs). The optical and structural properties of the prepared photoanodes before their application to DSSCs were investigated. The photocurrent density–voltage and external quantum efficiency characteristics of the DSSCs fabricated with these photoanodes were also analyzed and discussed. The experimental results confirmed the plasmonic enhancement effects on the performance of DSSCs, which indicated that cells loaded with the plasmonic-metal NPs yielded larger enhancement. The plasmonic effect of the Au–Ag alloy NPs significantly enhanced the broadband light absorption of dye molecules. The best cell was achieved using the photoanode loaded with Au–Ag alloy NPs, exhibiting a power conversion efficiency of 5.81%, which was ∼8.4% and 52.1% higher than that of the DSSCs with Au NPs and the reference cell, respectively. [ABSTRACT FROM AUTHOR]