The geological terrain mapping conducted by the Department of Mineral and Geosciences, Malaysia (JMG) is time-consuming especially for inaccessible or remote area. In order to improve the current practice, remotely sensed data such as aerial photographs and Landsat imagery were used to identify geological terrain features in Cameron Highlands, Pahang. It was found that features such as hillcrest, sideslope, footslope, straight slope, convex slope and concave slope were easily delineated using aerial photographs draped over a digital elevation model (DEM) compared to using Landsat imagery.
A retrospective study was carried out to determine the distribution of intraocular pressure in normal patients who came for vision problems at the Optometry Clinic, Universiti Kebangsaan Malaysia (UKM) Kuala Lumpur Campus, and to determine the differences in intraocular pressure with respect to age, gender and race. The cohort consisted of 148 subjects divided into five groups with age ranged from 10 to 59 years. The inclusion criteria were, subjects had no sistemic or ocular disease, subjects were not taking any medication, visual acuity was 6/6 or better, refractive errors < ±6.00D, astigmatism < 2.00D, anisometropia <2.00D, and mean intraocular pressure measured using the X-PERT tonometer and taken between 9 am to 2 pm. Statistical analysis (ANOVA) showed the mean intraocular pressure without consideration for age, race or gender was 12.6 mmHg (SD ±2.5). There was no significant differences in intraocular pressure between right and left eyes, between different age groups and between different genders. However, the intraocular pressuse for the Chinese was found to be significantly higher than the Malays. It was found that the intraocular pressure of patients who came for vision problems at the Optometry Clinic UKM follows a normal distribution and there was no significant diference found between right and left eyes, between different age groups and genders. Race seemed to contribute to the differences in intraocular pressure. Keywords: Age; clinic population; genders; pressure; intraocular pressure; race
Study site: Optometry clinic, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
This paper reports the infestation of psocid, Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelidae) in the insect museum at Medical Entomology Unit, Institute for Medical Research, Kuala Lumpur. These tiny organisms were recognised as museum insect pest and found frequently in the insect boxes containing mosquitoes, flies, cockroaches and butterflies. They feed on dead insect specimens and cause severe physical damages to the valuable reference specimens collected in the early 20th century. Hence, it is important to control their population immediately to prevent them from causing further deterioration to the museum collection.
MeSH terms: Academies and Institutes; Animals; Butterflies; Cockroaches; Entomology; Culicidae; Museums; Parasitic Diseases; Biomedical Research
Recent studies suggest that reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) may exert beneficial effects on health. Therefore this study evaluated the effects of H2O2 and gamma-tocotrienol (GTT), an antioxidant, on D-[2-3H]Glucose uptake by myotubes compared to insulin. Results showed that H2O2 and insulin significantly increased D-[2-3H]Glucose uptake. This was associated with an increased in Vmax but Michaelis constant (Km) of the transport system remained unchanged indicating that an increase in amount, rather than affinity, of the glucose transporter was involved in the process. Western blot studies confirmed that H2O2 increased the expressions of insulin sensitive glucose transporter, GLUT4 and also hexokinase (an enzyme which phosphorylates glucose and indirectly stimulates glucose uptake by cells). H2O2 and insulin also stimulated increased in PPAR-γ and IRS-1, which are proteins of the insulin transduction pathway. The present data however showed that GTT did not exert any effect on glucose uptake. Thus, the study showed that H2O2 mimicked insulin action in stimulating glucose uptake in myotube cells by influencing the insulin signaling pathway.
Kajian ini dilakukan bagi melihat keupayaan sel mononukleus sistem darah pusat membeza kepada sel osteoblas dan osteoklas secara in vitro bagi tiga tempoh proliferasi yang berbeza. Sel mononukleus sistem darah pusat dikulturkan di dalam medium pemilihan proliferasi bagi tiga tempoh proliferasi yang berbeza iaitu jangkamasa pendek (5 hari), sederhana (15 hari) dan panjang (30 hari). Keupayaan sel mononukleus untuk membeza kepada sel osteoblas dan osteoklas seterusnya diperhatikan pada setiap jenis sel ini. Medium proliferasi ditambah dengan faktor pembezaan asid askorbik dan β-gliserofosfat bagi membezakan sel mononukleus kepada sel osteoblas. Bagi pembezaan sel osteoklas pula, RANKL dan M-CSF ditambah ke dalam medium proliferasi. Bagi kawalan, sel yang sama digunakan tanpa penambahan faktor pembezaan. Viabiliti sel yang membeza daripada sel jangkamasa pendek, sederhana dan panjang menunjukkan sel-sel tersebut berupaya untuk bermandiri tanpa sebarang peningkatan yang signifikan sehingga 10 dan 14 hari dengan kehadiran faktor-faktor pembezaan tertentu di dalam medium pembezaan masing-masing. Analisis biokimia ke atas aktiviti alkali fosfatase (ALP) dan asid fosfatase rintang tartarat (TRAP) menunjukkan peningkatan yang signifikan (p<0.05) apabila dikulturkan di dalam medium pembezaan masing-masing. Kesimpulannya, keupayaan sel primitif untuk membeza kepada sel osteoblas dan osteoklas matang adalah hampir sama bagi ketiga-tiga jenis jangkamasa proliferasi tetapi mempunyai kadar proliferasi yang berlainan iaitu 0.37, 0.55 dan 0.72 pembahagian/hari masing-masing bagi sel jangkamasa pendek, sederhana dan panjang. Sel mononukleus yang diasingkan daripada darah periferi ini sangat primitif kerana berpotensi untuk membeza kepada dua jenis sel matang yang berasal daripada sel stem yang berbeza, justeru boleh dikategorikan sebagai sel stem multipoten.
Mammography is used as a screening tool for early detection of breast cancer. However, the radiation dose used should be as low as possible to minimize any effects on asymptomatic woman while maintaining the diagnostic value of the image as mammography is done annually. This study was done to determine the optimum exposure parameter in exposure control mode (AEC) for two combinations of anode/filter which were molybdenum/molybdenum (Mo/Mo) and molybdenum/rhodium (Mo/Rh) using the Lorad Selenia digital mammography system at the Women’s Breast Clinic, National Cancer Society (NCS). A CIRS012A mammography research of phantom 4 cm thickness with 50% glandularity was exposed in the cranio-caudal projection. TLD 100H was used to measure the entrance surface air kerma (ESAK). The AGD values were then calculated from the ESAK values, incorporating three correction factors (g, c and s) according to Euref protocol. Image quality was evaluated using signal to noise ratio (SNR). Figure of Merit (FOM) which is the ratio of the square of SNR to the AGD shows that 30 kVp is the optimum exposure parameter for a 4 cm thickness phantom with the use of Mo/Rh and Mo/Mo anode/filter combination. Non-parametric Spearman correlation test showed a negative linear relationship between AGD and SNR with increasing tube voltage for both anode/filters.
Keywords: Average glandular dose; CIRS012A phantom; exposure; full field digital mammography
Study site: Women’s Breast Clinic, National Cancer Society (NCS), Kuala Lumpur, Malaysia
Jelmaan surih yang merupakan pengitlakan jelmaan Radon, membenarkan pembinaan fitur imej tak-ubah kepada sekumpulan jelmaan imej yang dipilih. Dalam makalah ini, penulis mendemonstrasi kebergunaan fitur Jelmaan surih yang tak-ubah kepada herotan afin bagi membolehkannya membezakan aksara Jawi. Proses ini terdiri daripada menyurih imej dengan garis-garis lurus pada semua orientasi yang mungkin sambil menghitung beberapa fungsian bagi fungsi imej. Setiap kombinasi fungsian akan menghasilkan satu fungsi orientasi (atau fitur) bagi garis-garis surihan tersebut yang dikenali sebagai tandatangan objek. Jika fungsian yang digunakan mempunyai beberapa sifat pratakrif, tandatangan objek tersebut boleh digunakan untuk membezakan aksara Jawi secara afin. Ia bermanfaat untuk membina fitur tak-ubah terhadap putaran, translasi, penskalaan dan ricihan imej. Seterusnya, penulis mendemonstrasi kebergunaan fitur ini dengan membandingkan keputusan pengecamannya dengan keputusan yang diperoleh daripada fitur berasaskan momen afin tak-ubah. Eksperimen menggunakan Jelmaan surih telah menghasilkan keputusan yang cemerlang untuk pengecaman aksara Jawi bercetak dan tulisan tangan yang tak-ubah kepada herotan afin.
Aliran lapisan sempadan mantap dua matra bersebelahan titik genangan pada permukaan meregang dalam bendalir mikropolar dengan fluks haba permukaan boleh ubah dikaji. Halaju regangan dan halaju aliran bebas diandaikan berubah secara linear dari titik genangan. Persamaan dalam bentuk persamaan pembezaan separa dijelmakan kepada persamaan pembezaan biasa menggunakan penjelmaan keserupaan dan diselesaikan secara berangka menggunakan skim beza-terhingga yang dikenali sebagai kaedah kotak Keller. Kedua-dua aliran membantu dan aliran menentang dipertimbangkan. Lapisan sempadan terbentuk apabila halaju aliran bebas melebihi halaju regangan, sebaliknya, lapisan sempadan yang terbalik terbentuk apabila halaju aliran bebas kurang daripada halaju regangan. Keputusan berangka menunjukkan bahawa daya seretan berkurangan bagi bendalir mikropolar berbanding dengan bendalir Newtonan, dan ini seterusnya mengurangkan kadar pemindahan haba pada permukaan.
We used the density functional theory to calculate the vibrational frequencies of clusters of atoms. We obtained the bond distances and angles for which the energy of the Schrödinger equation is minimum. We found the bond distance between two Se atoms to be 232.1 pm when double zeta wave function was used. The frequency of oscillations was calculated to be 325.3 cm-1 but the intensity was zero because Se2 molecules were present in a very small number. When polarised double zeta wave function (DZP) was used, the bond length of Se2 was found to be 223.1 pm and the frequency is 367.4 cm-1. Similarly for other clusters of selenium, we calculated the frequencies and compared with the experimental data. The experimental Raman spectra give 250 cm-1 for a selenium glass. By comparing the experimental frequencies with those calculated we found that linear Se3 was present in the glass. This indicates the possibility of linear growth in the glass.
Small angle neutron scattering (SANS) technique has been widely employed in probing the microstructure of amorphous materials in the nanometer range. In aerogels system, the size range of 1 – 100 nm is of particular interest since the structural units, such as the pores and particles, often fall in this range. In a typical scattering experiment, scattered neutron intensity is measured as a function of the scattering angle. Various plots of intensity I(Q) and scattering vector, Q, can provide information about fractal dimensions, and particle and cluster sizes. In this study, SANS facilities, at Nuklear Malaysia (NM) and Badan Tenaga Atom Nasional (BATAN), Indonesia were used to analyse particle and cluster size of silica aerogels and titanium containing silica aerogels. Results from NM showed that silica aerogels have surface fractal dimension while titanium containing silica aerogels have mass fractal dimension. On the other hand, results from BATAN showed that both silica aerogels and titanium containing silica aerogels have mass fractal dimension. The particle size for silica aerogels and titanium containing silica aerogels samples obtained by NM were 11.18 ± 0.03 and 9.19 ± 0.06 nm, respectively while the respective values obtained from BATAN measurements were 11.78 ± 0.06 and 10.57 ± 0.07 nm.
Brushite (BR) and hydroxyapatite (HA) nanoparticles were fabricated through reverse microemulsion and hydrothermal processing route, respectively. The processing routes influenced nucleation and crystal growth although both methods resulted in nanorods formation. The calcium-to-phosphate ratio was 1.67, similar to that of natural bone and teeth. X-ray diffraction patterns revealed that the nanorods possessed almost pure crystal phase with negligible second phase. The ratio of particle length-to-width of BR and HA were approximately 3 and 4, respectively. To mimic the natural bone, chitosan/brushite (CTS/BR) and chitosan/hydroxyapatite (CTS/HA) nanocomposite scaffolds were prepared through rapid freeze-drying technique. The compressive strength of CTS/BR and CTS/HA nanocomposite scaffolds was compared for the first time. The compression test revealed that both the nanocomposite scaffolds exhibited reasonably high compressive strength of approximately 7 MPa. This value falls in the high-end range of cancellous bone’s compressive strength, with the compressive strength of CTS/HA 0.88 MPa more than CTS/BR.
Titanium dioxide nanoparticles were synthesized via low-temperature sucrose ester micelle-mediated hydrothermal processing route using titanium isopropoxide as the precursor. X-ray diffractometer revealed that the samples possessed a mixed crystalline phases consisting of anatase and brookite in which anatase was the main phase. Upon increasing the hydrothermal reaction temperature, the degree of crystallinity of the nanoparticles improved and their morphology transformed from bundles of needles to rods and to spheres. Photocatalytic behaviour of the as-synthesized nanoparticles was investigated by photodegradation of methylene blue solution in an ultraviolet A irradiating photoreactor. The as-synthesized nanoparticles exhibited higher photocatalytic performance as compared to the commercial counterpart.
Aloi Fe-Cr (Cr: 9-30 brt%) telah dikenakan pengoksidaan berkitar dalam Ar-20%O2, Ar-20%O2-5%H2O dan Ar-10%H2-5%H2O (tekanan separa oksigen, pO2 = 1.1 × 10-16atm), pada suhu 950oC. Pengukuran perubahan berat pengoksidaan menunjukkan secara umunnya bahawa peningkatan kandungan Cr dalam aloi akan mengurangkan kadar pengoksidaan. Untuk aloi Cr≤17%, ‘pengoksidaan pemecahan’ telah dapat diperhatikan. Untuk aloi Cr≥25%, penambahan berat adalah sangat rendah disebabkan oleh pembentukan lapisan Cr2O3. Penambahan 5%H2O kepada Ar-20%O2 dapat mempercepatkan lagi kadar pengoksidaan pada aloi yang mempunyai Cr≤20%. Walau bagaimanapun, kesan pencepatan ini tidak berlaku pada aloi yang mempunyai kandungan Cr yang tinggi. Analisis XRD menunjukkan aloi yang mempunyai kandungan Cr≤20%, wustit dan spinel terbentuk pada pO2 yang rendah, manakala pada pO2 yang tinggi, hematit, oksida besi dan spinel didapati terbentuk. Untuk aloi yang mempunyai kandungan Cr yang tinggi, hanya Cr2O3 dapat dikesan. Analisis keratan rentas menunjukkan bahawa spinel terbentuk melalui pengoksidaan dalaman. Ketebalan dan saiz zon oksida dalaman bertambah dengan bertambahnya kandungan Cr. Lapisan kromium oksida tunggal yang tumpat dapat diperhatikan apabila kandungan Cr melebihi 25%. Kerak oksida yang terbentuk di dalam wap air adalah lebih poros dan kurang padat berbanding kerak yang terbentuk dalam keadaan oksigen kering. Kesan wap air ke atas peningkatan pengoksidaan aloi Fe-Cr telah dibincangkan daripada aspek interaksi gas-pepejal.
Nano sized copper sulfide, iron sulfide and molybdenum sulfide were successfully synthesised via a simple hydrothermal method. Sodium thiosulfate pentahydrate (Na2S2O3×5H2O) and hydroxylamine sulfate ((H3NO)2×H2SO4) were used as the starting materials and reacted with the transition metal source at 200oC for 90 min. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR). Spherical shape CuS and FeS2 nanoparticles with high crystallinity were successfully produced. The transmission electron micrographs revealed the well-dispersibility of the produced nanoparticles. Scanning electron micrograph showed the MoS2 nanoparticles possessed a spherical shape with sheet-like structure covering on the outer surface of the particles.
The mechanical strength of magnetic lumen loaded handsheets was reported to be lower than the unloaded handsheets. This effect is due to the deposition of filler inside the fiber lumen and some on the fibre surface which interfere with the fibre to fibre bonding. Hence, in order to improve the handsheets strength, cationic starch is used as a dry strength additive. In this study, mixed tropical hardwood pulps were used throughout the experiment. The magnetite particles were deposited in the fibre lumen via the lumen loading technique. The addition of cationic starch was found to increase the handsheet strength. However, it disturbed and influenced the location and distribution of the magnetic fillers. Some of the magnetite particles were observed to be displaced from the fiber lumen and pit apertures. The charges of the filler particles and cationic starch played an important role in producing charge repulsion and pulling effect which lead to filler dislocation.
Kegunaan Cetyl CacaoateTM dalam pembangunan produk gincu telah dinilai dengan mengubah nisbah campuran lilin carnauba, jojoba ester dan Cetyl CacaoateTM berdasarkan reka bentuk uji kaji Simplex centroid {3,3} melalui penilaian sensori oleh sembilan orang panel terlatih dengan kaedah analisis diskriptif kuantitatif. Atribut-atribut yang dipersetujui untuk penilaian sensori dalam sesi pembangunan bahasa sensori adalah senang disapu, bau tengik, kekerasan, tektur, kelembapan, kesan sapuan, berkilat, berminyak, keselesaan selepas guna dan warna kekal. Keputusan menunjukkan bahawa kehadiran Cetyl CacaoateTM dalam pemformulasian gincu akan meningkatkan skor bagi atribut senang disapu tetapi akan merendahkan skor bagi atribut kekerasan. Kehadiran Cetyl CacaoateTM memberi gincu lebih berminyak manakala lilin carnauba mengurangkan kesan berminyak. Tiada bau tengik yang dikesan dalam semua sampel. Analisis variasi antara panel menunjukkan terdapat kebezaan pendapat antara panel dalam penilaian sampel-sampel bagi atribut keselesaan selepas guna dan warna kekal. Nisbah lilin-lilin kosmetik dalam pemformulasian dasar gincu yang mempunyai skor yang hampir sama dengan sampel rujukan adalah ½ Cetyl CacaoateTM : ½ jojoba ester atau 2/3 Cetyl CacaoateTM : 1/6 jojoba ester : 1/6 lilin carnauba.
Haloacetic acids (HAAs) are one of the most common disinfection by-products formed during chlorination of drinking water. An analytical method involving solid phase extraction (SPE) followed by gas-chromatograph mass-spectrometry (GC-MS) was developed and optimized using experimental design to determine the HAAs in water. Selectivity, percent recovery, and detection limit studies were carried out on a Silia-SAX (Trimethyl ammonium chloride) SPE. Under optimized conditions, average recoveries for nine HAAs spiked in drinking water samples range from 69.2% to 108.2 %. The relative
standard deviation (RSD) data were found to range from 2.5 % to 12.5% based upon five repeat recovery experiments and detection limit range of 0.16 to 0.009μg/l were obtained. On this basis, SPE was studied as a possible alternative to liquid-liquid extraction (LLE) for the analysis of HAAs in water. The performance of the SPE-GC-MS with actual water samples was tested.
Kandungan hidrokarbon polisiklik aromatik (PAH) dalam tiga spesies ikan yang berbeza tabiat pemakanan dan habitat, iaitu Lolong (Selar boops), Kerisi (Nemipterus peronii) dan Mengkarong (Trachinocephalus myops) dari luar pantai Pulau Perhentian, Malaysia ditentukan. Tiga individu daripada setiap spesies dipilih secara rawak dan kandungan 10 sebatian PAH diukur, iaitu fenantrena, antrasena, fluorantena, pirena, benzo(a)anthracene benzo(a)antrasena, krisena, benzo(a)fluorantena, benzo(k)fluorantena, benzo(e)pirena dan dibenzo(a,h)antrasena dalam otot ikan ditentukan. Pengekstrakan PAH menggunakan kaedah Soxhlet dan kandungannya diukur dengan kromatografi gas - spektrometri jisim (GC-MS). Jumlah PAH dalam tisu ikan yang dikaji adalah pada julat 17.89 – 42.18 ng/g berat basah dan 393.98 – 511.07 ng/g mengikut berat lipid. Kandungan PAH dalam tisu jenis ikan menurut berat basah adalah Mengkarong (42.18 ng/g)> Lolong (25.61 ng/g)> Kerisi (17.89 ng/g), sementara menurut berat lipid ialah Kerisi (511.07 ng/g)> Mengkarong (409.50 ng/g)> Lolong (393.98 ng/g). Otot Kerisi mengandungi kandungan lipid paling sedikit, iaitu 3.5 % berbanding dengan Lolong (6.5 %) dan Mengkarong (10.3 %). Tidak ada penumpukan PAH yang jelas dalam lipid tisu ikan (kolerasi Pearson, p>0.05) dan ketiga-tiga spesies ikan tidak menunjukkan kandungan PAH yang berbeza (ANOVA, p>0.05). Berdasarkan kadar pengambilan ikan pada 142.2 g/hari, pengiraan kepekatan potensi setara (PEC), iaitu nilai potensi karsinogenisiti sebatian PAH, ketiga-tiga spesies ikan adalah pada julat 0.41 – 0.63 ng/g berat basah. Nilai ini lebih rendah daripada nilai garis panduan yang ditetapkan oleh USEPA, iaitu 0.67 ng/g berat basah.
This study aimed to determine phylogenetic relationship between and among selected species of sea cucumbers (Echinodermata: Holothuroidea) using 16S mitochondrial ribosomal RNA (rRNA) gene. Phylogenetic analyses of 37 partial sequences of 16S mitochondrial rRNA gene using three main methods namely neighbour joining (NJ), maximum parsimony (MP) and maximum likelihood (ML) showed the presence of five main genera of sea cucumbers: Molpadia from order Molpadiida and four genera of order Aspidochirotida namely Holothuria, Stichopus, Bohadschia and Actinopyga. All of the 17 species obtained from Malaysia distributed among the main genera except within Actinopyga. Interestingly, Holothuria excellens was out of Holothuria group causing Holothuria to be paraphyletic. High bootstrap value and consistent clustering made Molpadia, Stichopus, Bohadschia and Actinopyga monophyletic. The relationship of Actinopyga with the other genera was unclarified and Stichopus was sister to Molpadia. The latter finding caused the resolution at order level unclear. The pairwise genetic distance calculated using Kimura 2-parameter model further supported and verified findings from the phylogenetic trees. Further studies with more samples and different mitochondrial DNA genes need to be done to get a better view and verification on the molecular phylogeny of sea cucumbers.
Kajian mengenai taburan ostrakod di dalam sedimen luar pantai telah dijalankan sekitar Pulau Besar, Johor. Sebanyak 11 stesen telah dipilih sebagai stesen pensampelan. Sebanyak 47 spesies ostrakod hidup dan mati daripada 37 genus dan 18 famili telah dikutip dan dikenal pasti. Sebanyak 1036 spesimen mati dan 932 spesimen hidup telah dijumpai di kawasan kajian. Spesies yang paling dominan adalah Pistocythereis cribriformis dan famili yang paling dominan ialah Trachyleberididae. Famili yang mempunyai kepelbagaian spesies terbanyak ialah Trachyleberididae dengan 14 spesies. Beberapa parameter fiziko-kimia telah diukur secara in-situ terdiri daripada suhu, saliniti, oksigen terlarut, pH dan kedalaman. Julat bagi setiap parameter masing-masing adalah 27.05-30.80oC, 31.20-34.01 ppt, 6.90-11.93 mg/L dan 6.60-20.50 m. Bagi parameter fiziko-kimia ex-situ seperti peratus bahan organik, pasir, lodak dan lempung dengan julat bagi setiap parameter masing-masing adalah 1.98-7.58%, 74.87-95.05%, 0.05-24.21% dan 0.75-9.74%. Tekstur sedimen di kawasan kajian boleh dikelaskan kepada pasir berlodak, pasir sangat halus, pasir halus, pasir sederhana dan pasir kasar. Indeks Shannon-Wiener, H(S) yang paling tinggi dicatatkan pada stesen ST 6 dengan 2.91 dan paling rendah pada stesen ST 11 iaitu 2.26. Kelimpahan dan kepelbagaian ostrakod adalah berkait dengan ciri-ciri sedimen. Peratus lodak menunjukkan korelasi positif yang signifikan manakala suhu dan peratus pasir menunjukkan korelasi negatif yang signifikan dengan kelimpahan ostrakod bentos. Parameter-parameter fiziko-kimia yang lain tidak menunjukkan hubungan yang signifikan.