24 research outputs found
Isolation of a pigment-producing bacterium chryseobacterium sp. from the tentacle of holothuria (lessonothuria) pardalis (Selenka 1867) from Pulau Tinggi, Johor
Chryseobacterium sp, a bacteria producing pigment was isolated from the tentacles of Holothuria (Lessonothuria) pardalis (Selenka 1867) from Pulau Tinggi, Johor. This study aimed to observe and genetically identified the presence of bacteria focusing on pigmentproducing bacteria. Thus, the partial 16S ribosomal RNA gene sequence of bacteria obtained and the shape, number of bacteria and gram staining observed using a digital compound microscope. Six gene sequence successfully obtained and the Basic Local Alignment Search Tool (BLAST) analysis suggested three species of bacteria identified from genus Pseudomonas, Chryseobacterium and Klebsiella. Besides, the neighbourhood-joining and Maximum Likelihood method had been used in the phylogenetic analysis to support the identification of bacteria species. The visible spectra of Chryseobacterium sp. were recorded between 400nm to 600nm which is a visible spectrum for carotenoid; orange pigment. However, further analysis is needed to confirm the characterisation and the potential of this pigment in industria
Isolation of bacteria associated with the tentacles of holothuria (lessonothuria) pardalis (selenka 1867) from Pulau Tinggi, Johor including pigment-producing chryseobacterium sp.
Pigment-producing microorganisms have become a main focus due to the search
of food-grade microbial pigments for natural food colourant industry. Therefore,
this study aimed to isolate and genetically identify bacteria including pigmentproducing
bacterial strains associated with the tentacles of Holothuria
(Lessonothuria) pardalis (Selenka 1867) from Pulau Tinggi, Johor.
Morphological characteristics of bacteria based on Gram staining were observed
using a digital compound microscope. Partial 16S ribosomal RNA (rRNA) gene
sequencing was also incorporated to support the morphological approach. A
number of six partial gene sequences of non-protein coding 16S rRNA were
obtained and the Basic Local Alignment Search Tool (BLAST) analysis
suggested the presence of three known bacteria species from the genera of
Pseudomonas, Chryseobacterium and Klebsiella. The neighbourhood-joining
method and Maximum Likelihood method used in the phylogenetic analysis
supported the identification and classification of the bacteria species. Among the
bacterial isolates, only strain B14 identified as Chryseobacterium sp. produced
pigment i.e. orange pigment. The highest point of cell density of
Chryseobacterium sp. was recorded at 16 hours. However, further analysis is
needed to confirm the pigment characterisation and the potential of this pigment
to be exploited as natural colourant in the food industry
Mitogenomic phylogeny of the common long-tailed macaque (Macaca fascicularis fascicularis)
Background
Long-tailed macaques (Macaca fascicularis) are an important model species in biomedical research and reliable knowledge about their evolutionary history is essential for biomedical inferences. Ten subspecies have been recognized, of which most are restricted to small islands of Southeast Asia. In contrast, the common long-tailed macaque (M. f. fascicularis) is distributed over large parts of the Southeast Asian mainland and the Sundaland region. To shed more light on the phylogeny of M. f. fascicularis, we sequenced complete mitochondrial (mtDNA) genomes of 40 individuals from all over the taxon’s range, either by classical PCR-amplification and Sanger sequencing or by DNA-capture and high-throughput sequencing.
Results
Both laboratory approaches yielded complete mtDNA genomes from M. f. fascicularis with high accuracy and/or coverage. According to our phylogenetic reconstructions, M. f. fascicularis initially diverged into two clades 1.70 million years ago (Ma), with one including haplotypes from mainland Southeast Asia, the Malay Peninsula and North Sumatra (Clade A) and the other, haplotypes from the islands of Bangka, Java, Borneo, Timor, and the Philippines (Clade B). The three geographical populations of Clade A appear as paraphyletic groups, while local populations of Clade B form monophyletic clades with the exception of a Philippine individual which is nested within the Borneo clade. Further, in Clade B the branching pattern among main clades/lineages remains largely unresolved, most likely due to their relatively rapid diversification 0.93-0.84 Ma.
Conclusions
Both laboratory methods have proven to be powerful to generate complete mtDNA genome data with similarly high accuracy, with the DNA-capture and high-throughput sequencing approach as the most promising and only practical option to obtain such data from highly degraded DNA, in time and with relatively low costs. The application of complete mtDNA genomes yields new insights into the evolutionary history of M. f. fascicularis by providing a more robust phylogeny and more reliable divergence age estimations than earlier studies
Q-switched fibre laser using Samarium oxide for C-band region
We demonstrated the usage of samarium oxide (Sm2O3) polymer film as a saturable absorber (SA) for generating stable Q-switched fibre laser at the C-band region. The SA was prepared by embedding a commercial Sm2O3 powder into polyvinyl alcohol (PVA) solution to form a Sm2O3-PVA film. The obtained film was then cut into a square shape of 1 mm x 1mm and adhered to the tip of fibre ferrule by using index matching gel. A stable Q-switching operation presence from 52 mW to 164 mW pump power at 1568 nm wavelength. Under this pump power, the repetition rate increased from 24.34 kHz to 55.80 kHz, while the pulse width reduced from 13.29 µs to 6.96 µs. The obtained Q-switching operation has a signal-to-noise ratio (SNR) of 38 dB with a maximum output power and pulse energy of 8.58 mW and 123.27 nJ, respectively. This finding shows that the Sm2O3 has good potential to be used as an alternative passive SA for the C-band all-fibre laser seed pulse
Airco Wind Turbine Prototype Design And Development
The AIRco Wind Turbine is a new kind of product that can generate an electrical power from aerodynamic air flow that can be used to charge the phone. It is a green technology that used the wind as a source of energy to rotate the wind turbine and small electrical motor to generate an electrical power. This product is assembled and attached to the side of motorcycles basket in order to collect the wind energy to generate an electric power and also come with a gadget storage to place the phone when charging the battery. When travelling by riding the motorcycle, the energy from the aerodynamic air flow that occurs when increase the acceleration of the motorcycle can be converted to be an electrical power with adding few electrical components such as 12 volt DC electrical motor 5 volt voltage regulator and USB port which can used to charge our gadgets. It is an alternative way to generate the electrical power using the aerodynamic air flow as a free green energy. The objectives of this research are to analyze and propose the best blade design for wind flow, to design and develop functional prototype of AirCo Wind Turbine and to testing power generation from prototype
DNA barcoding of holothuria (mertensiothuria) leucospilota from Pulau Tinggi, Johor
Sea cucumber or locally known as gamat and timun laut is a well-known attraction of Pulau Langkawi, Kedah, Malaysia. Not only limited to Pulau Langkawi, sea cucumber can also be found in other coastal water areas of Malaysia. However, the species richness and genetic diversity of sea cucumber in Pulau Tinggi, Johor is still unknown to the marine scientific communities, especially for Holothuria (Mertensiothuria) leucospilota, the most dominant species in Malaysia. Therefore, this study aimed to generate DNA barcodes of H. leucospilota from Pulau Tinggi. Protein-coding cytochrome c oxidase 1 (CO1) mtDNA gene was used as it is commonly and widely used for molecular species identification via DNA barcoding. Polymerase chain reaction (PCR) and DNA sequencing were incorporated to generate the DNA barcodes of CO1 mtDNA gene. The BLAST program confirmed the species status of the sea cucumber specimens as H. leuscospilota or locally known as bat puntil or white threads fish. The application for GenBank, NCBI, U.S. National Library of Medicine registration was successfully accepted on October 17, 2019 with accession numbers of MN580537 and MN580538). The phylogenetic trees i.e neighbor joining tree (NJ, distancebased method), maximum parsimony tree (MP, character-based method) and maximum likehood tree (ML, character-based method) reconstructed using MEGA X software version 10.0.5 (BETA) further supported the species status of the sea cucumber specimens from Pulau Tinggi as H. leuscospilota. This is the first record of CO1 mtDNA barcodes of H. leuscospilota from Pulau Tinggi, Johor, Malaysia
In vivo evaluation of oxidized multiwalled-carbon nanotubes-mediated hyperthermia treatment for breast cancer
Breast cancer is one of the most common types of cancer that contribute to high mortality worldwide. Hyperthermia (HT) was introduced as one of the alternative treatments to treat breast cancer but has major drawback of damaging normal adjacent cells. This study explores the integration effect of multiwalled-carbon nanotubes (MWCNTs) in combination with hyperthermia treatment for breast cancer therapy regimes. In this study, acid-functionalized MWCNTs (ox-MWCNTs) were prepared by acid washing methods using H2SO4/HNO3 (98%/68%) with the ratio of 3:1 (?/?) and characterized by colloidal dispersibility test, FTIR, TGA, XRD, FESEM and EDX analysis. EMT6 tumor-bearing mice were treated with ox-MWCNTs in combination with local HT at 43 °C. The tumor progression was monitored and the influence of immune response was evaluated. Results from this study demonstrated that mice from ox-MWCNTs in combination with local HT treatment group experienced complete tumor eradication, accompanied by a significant increase in median survival of the mice. Histological and immunohistochemical analysis of tumor tissues revealed that tumor treated with combined treatment underwent cell necrosis and there was a significant reduction of proliferating cells when compared to the untreated tumor. This observation is also accompanied with an increase in Hsp70 expression in tumor treated with HT. Flow cytometry analysis of the draining lymph nodes showed an increase in dendritic cells infiltration and maturation in mice treated with combined treatment. In addition, a significant increase of tumor-infiltrated CD8+ and CD4+ T cells along with macrophages and natural killer cells was observed in tumor treated with combined treatment. Altogether, results presented in this study suggested the potential of ox-MWCNTs-mediated HT as an anticancer therapeutic agent, hence might be beneficial in the future of breast cancer treatment
The first Malay database toward the ethnic-specific target molecular variation
BACKGROUND:The Malaysian Node of the Human Variome Project (MyHVP) is one of the eighteen official Human Variome Project (HVP) country-specific nodes. Since its inception in 9(th) October 2010, MyHVP has attracted the significant number of Malaysian clinicians and researchers to participate and contribute their data to this project. MyHVP also act as the center of coordination for genotypic and phenotypic variation studies of the Malaysian population. A specialized database was developed to store and manage the data based on genetic variations which also associated with health and disease of Malaysian ethnic groups. This ethnic-specific database is called the Malaysian Node of the Human Variome Project database (MyHVPDb).
FINDINGS:Currently, MyHVPDb provides only information about the genetic variations and mutations found in the Malays. In the near future, it will expand for the other Malaysian ethnics as well. The data sets are specified based on diseases or genetic mutation types which have three main subcategories: Single Nucleotide Polymorphism (SNP), Copy Number Variation (CNV) followed by the mutations which code for the common diseases among Malaysians. MyHVPDb has been open to the local researchers, academicians and students through the registration at the portal of MyHVP ( http://hvpmalaysia.kk.usm.my/mhgvc/index.php?id=register ).
CONCLUSIONS:This database would be useful for clinicians and researchers who are interested in doing a study on genomics population and genetic diseases in order to obtain up-to-date and accurate information regarding the population-specific variations and also useful for those in countries with similar ethnic background
Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic
Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer
Passively Q-switched fibre laser utilizing erbium-doped fibre saturable absorber for operation in C-band region
In this paper, a stable and robust all-fibre passively Q-switched erbium-doped fibre laser (EDFL) emitting at 1558 nm is described. The proposed laser utilizes an 11 cm long erbium-doped fibre as saturable absorber (SA). The fibre SA features a linear optical absorption of about 13 dB in the Q-switched EDFL operating regime. By elevating the input pump power from the threshold of 60 mW to the maximum available power of 142 mW, a pulse train with a maximum repetition rate of 86 kHz, minimum pulse width of 3.39 µs, maximum average output power of 10.5 mW, maximum pulse energy of 122 nJ and maximum peak power of 36 mW are obtained. The signal to noise ratio (SNR) of the spectrum is measured to be around 70 dB. This fibre SA is simple, reliable, compact and alignment free. Thus it is suitable for making a portable pulse laser source