164 research outputs found

    Generation of Q-switched thulium-doped fiber laser (TDFL) using differentsaturable absorbers

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    A Q-switched Thulium-doped Fiber Laser (TDFL) operating at approximately 2 µm wavelength is successfully generated by using four different saturable absorbers (SAs) which are nitrogen-doped graphene in PVA (NG:PVA), nitrogen-doped graphene in PEO (NG:PEO), single-walled carbon nanotube in PVA (SWCNT:PVA), and high pressure carbon monoxide carbon nanotube in PVA (CNTHiPCO:PVA). The SAs integrated in the cavity were able to provide the real saturable absorption in modulating the intra-cavity losses. SWCNT gives the best results with the highest repetition rate and lowest pulse width of 57.45 kHz and 1.958 nJ correspondingly as compared to the other three SAs

    An overview of moisture damage performance tests on asphalt mixtures

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    This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage

    The implementation of unmanned aerial vehicle (UAV) for slope mapping

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    This paper discusses the applications of unmanned aerial vehicle (UAV) for slope mapping and its important parameters including perimeter, area and volume of certain selected areas at Perumahan Taman Gambang Damai in Kuantan Pahang. This study also focused on determining the potential slope hazard based on slope angle. Modern UAV able to take high quality image which essential for the effectiveness and nature of normal mapping output such as Digital Elevation Model (DEM) and Digital Orthophoto. This photo captured by the UAV will later transfer to Agisoft to generate full map of study area. With the help of Global Mapper, the measurement (perimeter, area and volume) of selected study areas can be determined easily and considered as the main interest in this study. In addition, another outcome of this study is, this modern method of mapping helps researchers and engineers to study the possibility of slope hazard based on their respective slope angle (according to slope classes). In conclusion, modern technology of UAV proves to be very effective for mapping in geotechnical engineering. Slope mapping help researchers and engineers to obtain slope measurement within short period of time compare to previous traditional method

    Genome-scale compositional comparisons towards drought tolerant genes in rice, date palm, maize and thale cress

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    Extreme and unpredictable weather has gradually posed a threat to the global production of the world’s staple food crops such as rice, wheat, and maize. For instance, drought had caused significant losses which makes drought-tolerant planting materials increasingly important not only for food security but also for the sustainability of agricultural activities. This could be done by first exploring the genetic materials that are responsible for survival in hot and dry conditions other than solely relying on conventional methods. The availability of various comparative genomics tools has allowed the identification of several potential drought-tolerant genes in plants such as wheat, tomato, maize and others. In this study, potential drought-tolerant genes in rice are predicted by identifying orthologous proteins between four species; Oryza sativa (rice), Arabidopsis thaliana (thale cress), Zea mays (maize) and Pheonix dactylifera (date palm) using InParanoid, SonicParanoid and Mauve software tool. From the 9,952 orthologous proteins found among the four species, 8,573 sequences were annotated and assigned to 5,729 GO terms; classified into the biological process category (54%, 2777 sequences), molecular function category (65%, 3223 sequences) and cellular component category (58%, 2539 sequences). Sixty five genes were found to be represented under four drought tolerance GO terms; regulation of response to water deprivation (GO:2000070; 1 gene, 1.54% ); response to water deprivation (GO:0009414, 47 genes, 72.31%); behavioural response to water deprivation (GO:0042630, 11 genes, 16.92%) and; cellular response to water deprivation (GO:0042631, 6 genes, 9.23%). Narrowing down potential drought-stress response genes through this study could contribute to a better understanding and knowledge on the biological and functional analysis of drought-tolerant genes in rice

    Ocular injury and its associated factors among patients admitted to a hospital in Selangor

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    Background: There are various factors associated with ocular injury such as age, gender, nationality, ethnicity, work related factor and alcohol intake. The aim of this study is to determine the proportion of ocular injury and its associated factors among patients admitted to a hospital in Selangor. Materials and Methods: A hospital-based cross-sectional study design and universal sampling method were used. Data collection was conducted in a hospital in Selangor by retrospective review of secondary data for last six months from data collection period. The data were transferred into a proforma. The data analysis was done using Statistical Package for Social Sciences (SPSS) version 20. Chi square test was done to determine the relationship between the associated factors of ocular injury. Result: There were 11 8 proforma collected. There were higher proportion of ocular injury in age group of 20-39 (59.3%), male (92.4%), Malay (47.5%) and Malaysian (65.3%). Cases of unilateral eye involvement were highest (88.1%) and occurred unintentionally (94.9%). Mostly (80.5%), patients sought immediate treatment after ocular injury. The commonest place of incident and source of ocular injury were industrial premises (33.1%) and blunt object (28.0%) respectively. 52.5% of ocular injury were of non penetrating diagnosis. There was high proportion of ocular injury due to work related factor (44.9%). Besides, there were significant relationship between types of nationality with work related factor (p=0.001) and types with sources of injury (p=0.001). There was no relationship between period of time taken before treatment with types of injury (p=0.118). Conclusion: In short, ocular injury is more common in age group of 20-39 years old, male, Malaysian and Malay. There is high proportion of ocular injury due to work related factor. There are also significant relationship between types of nationality with work related factor and types of ocular injury with sources of injury among patients with ocular injury

    Effects of Indole-3-Butyric Acid (IBA) and rooting media on rooting and survival of air layered wax apple (Syzygium samarangense) CV Jambu Madu

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    The wax apple or jambu madu, is a non-climacteric tropical fruit from Myrtaceae family and widely cultivated in South East Asia. The limited availability of good quality seedlings of wax apple is the main problem to development of flourish it’s market share in the current fruit industry. Therefore, in order to produce good quality planting materials, a study aimed at optimizing propagation and adventitious rooting technique and survivability of wax apple air layer was conducted. In this study, four different levels of Indole-3-Butyric Acid (IBA) concentration (0, 1000, 1500 and 2000 mg L-1) and three rooting media (sphagnum moss, vermicompost and garden soil) were applied after removal of bark (phloem) on the shoot to determine the effect on rooting and survivability of the wax apple air layer under field conditions. The results showed that the wax apple shoots treated with 2000 mg L-1 IBA produced the significantly higher number of roots, increased length of root, diameter of branch, length of branch, number of leaf and leaf area of air layers. In addition, the highest chlorophyll content and stomatal aperture were recorded in 2000 mg L-1 IBA treatment compared to other treatments including control. Vermicompost medium was better than garden soil and sphagnum moss in respect of rooting and survivability of air layers. The results showed that the combination of 2000 mg L-1 IBA and vermicompost as rooting media give the best combination to root initiation, root number, root length and survival rate (100%) of wax apple air layers. From this study, it can be concluded that 2000 mg L-1 IBA and vermicompost treatment enhance the root initiation, early establishment and survivability of wax apple air layered under field conditions

    High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence

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    Blue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m-2. Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures

    A conventional multiplex PCR for the detection of four common soil-transmitted nematodes in human feces : development and validation

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    Soil-transmitted helminth (STH) infections, mainly caused by Ascaris lumbricoides, Trichuris trichiura, and hookworms, are among the most common intestinal parasites that infect humans. The infections are widely distributed throughout tropical and subtropical countries, including Malaysia, particularly in underprivileged communities. Microscopic and culture techniques have been used as a gold standard for diagnostic techniques. However, these methods yield low sensitivity and specificity, laborious and time-consuming. Therefore, simple, rapid, and accurate alternative methods are needed for the simultaneous detection of STH infections. Although advanced technologies such as real-time multiplex PCR have been established, the use of this technique as a routine diagnostic is limited due to the high cost of the instrument. Therefore, a single-round multiplex conventional PCR assay for rapid detection of four STH species in the fecal sample was developed in this study. To perform the single-round multiplex PCR, each pair of species-specific primers was selected from target genes, including Ancylostoma duodenale (Internal Transcribed Spacer 2; accession No. AJ001594; 156 base pair), Necator americanus (ITS 2; accession No. AJ001599; 225 base pair), Ascaris lumbricoides (Internal Transcribed Spacer 1; accession No. AJ000895; 334 base pair) and Trichuris triciura (partial ITS 1, 5.8s rRNA and partial ITS 2; accession No. AM992981; 518 base pair). The results showed that the newly designed primers could detect the DNA of STH at low concentrations (0.001 ng/μl) with no cross-amplification with other species. This assay enables the differentiation of single infections as well as mixed infections. It could be used as an alternative and is a convenient method for the detection of STHs, especially for the differentiation of N. americanus and A. duodenale

    Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

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    Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
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