Group B beta-hemolytic streptococcus (GBS) sepsis is a serious bacterial infection in neonates, with significant morbidity and mortality. We report here a neonate with late onset GBS infection manifesting as a urinary tract infection (UTI) in an infant presenting with prolonged neonatal jaundice. The pathogenesis of this late onset is postulated.
Assessment of schoolchildren's knowledge, attitudes, and practices towards influenza A (H1N1) is crucial as schools play a major role in spreading the infection. The aims of this study were to determine the level of knowledge, attitudes, and practices on influenza A (H1N1) and the factors associated with practices of preventive behavior.A cross sectional study was conducted from July until December 2010. Two public secondary schools for two districts in Kelantan, Malaysia were randomly selected. Data were collected using a self-administered questionnaire. The questionnaire consisted of five constructs: sociodemographic, risk factors of containing influenza A (H1N1) infection, knowledge, attitudes, and practices. The questionnaire had been te,sted for its construct validity and reliability. General linear regression was applied in the data analysis. A sample of 436 secondary school students were recruited in this study involved Malay students aged 16 years old. The total knowledge, attitudes and practices scores for the overall respondents were 69.4, 82.2, and 73.8%, respectively. The significant influencing factors for the practices of preventive behavior were attended talk on H1N1 and attitudes score.This study suggested that health education is important for promoting the health of adolescents and contributing to the overall health of the public so that they will take precautions against the H1N1 infection.
There is a high rate of unintended pregnancies in Malaysia due to low contraceptive use. Only 30% of married women use modern contraceptive methods. Emergency contraception (EC) is used within a few days of unprotected sex to prevent pregnancy. The purpose of this study was to investigate the knowledge, attitudes, and practices regarding EC pill use among Malay women. A cross sectional study was conducted among married female staff using stratified random sampling from 15 faculties in the Universiti Putra Malaysia (UPM). Data about sociodemographic factors, reproductive health, knowledge, attitudes and practices regarding EC use were gathered using validated self-administered questionnaire. The response rate was 87%. Half the 294 subjects who participated had a low knowledge, 33.0% a moderate knowledge and 17.0% a good knowledge about the EC pill. Eighty-eight percent of respondents had a positive attitude and 12.0% a negative attitude toward EC. Eleven percent of respondents had previously used EC. Unplanned and unwanted pregnancies were reported by 35.0% and 14.0% of respondents, respectively. Most respondents lacked knowledge about the indications for using EC, its mechanism of action, when it can be used and its side effects. Our findings show a need to educate women about EC.
Study site: 15 faculties in Universiti Putra Malaysia, Serdang. Selangor, Malaysia
This paper presents the temperature characteristics of silicon nanowire transistors (SiNWTs) and examines the effect of temperature on transfer characteristics, threshold voltage, I(ON)/I(OFF) ratio, drain-induced barrier lowering (DIBL), and sub-threshold swing (SS). The (MuGFET) simulation tool was used to investigate the temperature characteristics of a transistor. The findings reveal the negative effect of higher working temperature on the use of SiNWTs in electronic circuits, such as digital circuits and amplifiers circuits, because of the lower I(ON)/I(OFF) ratio, higher DIBL, and higher SS at higher temperature. Moreover, the ON state is the optimum condition for using a transistor as a temperature nano-sensor.
MeSH terms: Amplifiers, Electronic; Fever; Hot Temperature; Silicon; Temperature; Nanowires
In seabed logging the magnitude of electromagnetic (EM) waves for the detection of a hydrocarbon reservoir in the marine environment is very important. Having a strong EM source for exploration target 4000 m below the sea floor is a very challenging task. A new carbon nanotubes (CNT) fibres/aluminium based EM transmitter is developed and NiZn ferrite as magnetic feeders was used in a scaled tank to evaluate the presence of oil. Resistive scaled tank experiments with a scale factor of 2000 were carried out. X-ray Diffraction (XRD), Raman Spectroscopy and Field Emission Scanning Electron Microscope (FESEM) were done to characterize the synthesized magnetic feeders. Single phase Ni0.76Mg0.04Zn0.2Fe2O4, obtained by the sol-gel method and sintered at 700 degrees C in air, has a [311] major peak. FESEM results show nanoparticles with average diameters of 17-45 nm. Samples which have a high Q-factor (approximately 50) was used as magnetic feeders for the EM transmitter. The magnitude of the EM waves of this new EM transmitter increases up to 400%. A curve fitting method using MATLAB software was done to evaluate the performance of the new EM transmitter. The correlation value with CNT fibres/aluminium-NiZnFe2O4 base transmitter shows a 152.5% increase of the magnetic field strength in the presence of oil. Modelling of the scale tank which replicates the marine environment was done using the Finite Element Method (FEM). In conclusion, FEM was able to delineate the presence of oil with greater magnitude of E-field (16.89%) and the B field (4.20%) due to the new EM transmitter.
Magnetic nanoparticles in the hollow region of carbon nanotubes have attraction due to their changing physical electrical and magnetic properties. Nickel zinc ferrite plays an important role in many applications due to its superior magnetic properties. Ni0.8Zn0.2Fe2O4 single crystals were encapsulated in multiwall carbon nanotubes (MWCNTs). The magnetic nano crystals were prepared using a sol-gel self combustion method at the sintering temperature of 750 degrees C and were characterized by XRD, FESEM, TEM and VSM. Initial permeability, Q-factor and relative loss factor were measured by impedance vector network analyzer. XRD patterns were used for the phase identification. FESEM images show morphology and dimensions of the grains of Ni0.8Zn0.2Fe2O4 single crystals and Ni0.8Zn0.2Fe2O4 single crystals in MWCNTs. TEM images were used to investigate single crystal and encapsulation of Ni0.8Zn0.2Fe2O4 single crystals in the MWCNTs. VSM results confirmed super paramagnetic behaviour of encapsulated Ni0.8Zn0.2Fe2O4 single crystals. It was also attributed that encapsulated Ni0.8Zn0.2Fe2O4 single crystals in MWCNTs showed a higher initial permeability (51.608), Q-factor (67.069), and low loss factor (0.0002) as compared to Ni0.8Zn0.2Fe2O4 single crystals. The new encapsulated Ni0.8Zn0.2Fe2O4 single crystals in the MWCNTs may have potential applications in electronic and medical industries.
In this study, Single-Walled and Multi-Walled Carbon Nanotubes in their perfect forms were investigated by the Finite Element Method. Details on the modeling of the structure are provided in this paper, including the appropriate elements, the element properties that should be defined based on the atomic structure of Carbon Nanotubes and the corresponding chemical bonds. Non-covalent van der Waals interactions between two neighbor atoms as well as the required approximations for the modeling of the structures with this kind of interaction are also presented. Specific attention was dedicated to the necessity of using some time- and energy-consuming steps in the simulation process. First, the effect of simulating only a single ring of the whole structure is studied to find out if it would represent the same mechanical behavior as the long structure. Results show that by applying an appropriate set of boundary conditions, the stiffness of the shortened structure is practically equal to the long perfect structure. Furthermore, Multi-Walled Carbon Nanotube structures with and without defining the van der Waals force are studied. Based on the observations, applying the van der Waals force does not significantly influence the obtained Young's modulus of the structure in the case of a uniaxial tensile test.
Electromagnetic (EM) waves transmitted by Horizontal Electric Dipole (HED) source to detect contrasts in subsurface resistivity termed Seabed Logging (SBL) is now an established method for hydrocarbon exploration. However, currently used EM wave detectors for SBL have several challenges including the sensitivity and its bulk size. This work exploits the benefit of superconductor technology in developing a magnetometer termed Superconducting Quantum Interference Device (SQUID) which can potentially be used for SBL. A SQUID magnetometer was fabricated using hexagon shape-niobium wire with YBa2Cu37O, (YBCO) as a barrier. The YBa2Cu37O, samples were synthesized by sol-gel method and were sintered using a furnace and conventional microwave oven. The YBCO gel was dried at 120 degrees C in air for 72 hours. It was then ground and divided into 12 parts. Four samples were sintered at 750 degrees C, 850 degrees C, 900 degrees C, and 950 degrees C for 12 hours in a furnace to find the optimum temperature. The other eight samples were sintered in a microwave with 1100 Watt (W) with a different sintering time, 5, 15, 45 minutes, 1 hour, 1 hour 15 minutes, 1 hour 30 minutes, 1 hour 45 minutes and 2 hours. A DEWAR container was designed and fabricated using fiberglass material. It was filled with liquid nitrogen (LN2) to ensure the superconducting state of the magnetometer. XRD results showed that the optimum sintering temperature for the formation of orthorhombic Y-123 phase was at 950 degrees C with the crystallite size of 67 nm. The morphology results from Field Emission Scanning Electron Microscopy (FESEM) showed that the grains had formed a rod shape with an average diameter of 60 nm. The fabricated SQUID magnetometer was able to show an increment of approximately 249% in the intensity of the EM waves when the source receiver offset was one meter apart.
This paper addresses the growth of nano-structured MgZnO thin films by sol-gel spin coating method which will be used as a template layer to grow carbon nanotubes. The nano-structured MgZnO films were deposited on platinized (100) silicon substrates. In this work, we focused on the effect of aging and Mg content on the film structure and resistivity. Sols with Mg content of 10, 30 and 50 at.% were subjected to aging times of between 3 to 240 hours. Results from scanning (SEM) and field emission scanning electron (FESEM) microscopes and surface profiler (SP) showed that the sol aging increased the thickness, grain size and surface roughness for aging up to 240 hours. The energy dispersive analysis by X-ray (EDAX) confirmed the element of Mg in the ZnO films. The electrical resistivity also increased with aging time as confirmed by four point probe method. The results suggest that appropriate aging of the sol is important for improving physical quality and electrical performance of MgZnO thin films derived from sol-gel technique.
Transparent nanostructured ZnO thin films were successfully deposited using sol-gel spin coating method on a quartz substrate. The 0.4 M ZnO solution gel was prepared using zinc acetate dihydrate (Zn(CH3COO)22H2O) as the precursor, 2-methoxyethanol as the solvent and monoethanolamine (MEA) as the stabilizer. The electrical and optical properties dependencies on the annealing temperature of the nanostructured ZnO thin films were investigated. It was found that as the annealing temperature increased, the particle size, conductivity and the peak of the UV emission also increased.
We report the use of a new precursor as active agents to promote the growth of carbon nanotubes (CNT) in methane ambient using a simple thermal chemical vapour deposition method. The agents consist of ammonia and methanol mixed at different ratios and was found to enhance the growth of CNTs. The optimum methanol to ammonia ratio was found to be 8 to 5, whereby longer and denser CNTs were produced compared to other ratios. The result was found otherwise when the experiment was done solely in methane ambient. In addition, CNT growth on substrates coated with double layer Ni catalyst was improved in terms of quality and density compared to a single coated substrates. This finding is supported by Raman spectrometry analysis.
Although there have been many new developments in the treatment of leukaemia with the use of new anti-leukaemic agents and stem cell transplantation, drug resistance and treatment failure remain a great challenge for the attending physician. Several studies have suggested that leukaemic stem cells (LSCs) play a pivotal role in chemoresistance and metastasis and the mechanisms by which these cells do so have also been elucidated. There is increasing evidence to show that there exists a large pool of therapeutic targets in LSCs and that the eradication of these cells is feasible with some promising results. This article gives an overview of different types of cancer stem cells (CSCs) derived from various types of leukaemia, the mechanisms by which LSCs contribute to drug resistance and metastasis and some recent advances in targeted therapy against LSCs.
Acral melanoma has been reported to have distinctive clinical presentation and ethnic distribution compared to other histological types of malignant melanoma. Acral melanoma also exhibits distinctive focused gene amplifications, including cyclin D1 overexpression. We reviewed archived histological material of malignant melanoma in the Sarawak General Hospital from year 2004 to 2010. 43 tumours, comprising 28 acral melanoma and 15 non-acral melanoma, had sufficient material to be included in the study. The majority (36%) of acral melanoma tumours occurred in the heel. The tumours were analyzed for cyclin D1 expression by immunohistochemistry. 68% of acral melanoma were cyclin D1 positive compared to a positivity of 33% in non-acral tumours. This difference was statistically significant (p < 0.05). This finding may improve the histological diagnosis of acral melanoma and detection of positive resection margins.
Melanoma is a lethal skin cancer that occurs predominantly among Caucasians. In Malaysia, the incidence of melanoma is low. This is a retrospective study of clinical and histopathological features of patients with cutaneous melanoma who were seen at the University Malaya Medical Centre from 1998 to 2008. Thirty-two patients with cutaneous melanoma were recorded during that period. Of these, 24 had sought treatment at the onset of disease at our centre. Chinese patients constituted the largest group (19 cases). The median age of these 24 patients at the time of presentation was 62 years. 16 patients had melanoma involving the lower limb with 12 affecting the sole of the foot. None had melanoma arising from the face. Histopathology showed nodular melanoma in 22 cases (91.6%), with superficial spreading and acral lentiginous melanoma diagnosed in 1 case each. The majority of patients (62.5%) were found to be in Stage III of the disease at the time of diagnosis.
Microgravity, hypergravity, vibration, ionizing radiation and temperature fluctuations are major factors of outer space flight affecting human organs and tissues. There are several reports on the effect of space flight on different human cell types of mesenchymal origin while information regarding changes to vascular endothelial cells is scarce. Ultrastructural and cytophysiological features of macrovascular endothelial cells in outer space flight and their persistence during subsequent culturing were demonstrated in the present investigation. At the end of the space flight, endothelial cells displayed profound changes indicating cytoskeletal lesions and increased cell membrane permeability. Readapted cells of subsequent passages exhibited persisting cytoskeletal changes, decreased metabolism and cell growth indicating cellular senescence.
MeSH terms: Cell Survival; Cells, Cultured; Cytoskeleton/ultrastructure*; Microscopy, Electron, Scanning/methods; Space Flight*; Time Factors; Weightlessness/adverse effects*; Cell Aging/physiology*; Cell Proliferation; Human Umbilical Vein Endothelial Cells/cytology*; Human Umbilical Vein Endothelial Cells/physiology
The aim of this study was to examine cells (split-sample) that were retained on sampling devices used to collect conventional Pap smears (primary smears) in order to evaluate specimen adequacy and cytological diagnosis of scrapings that are routinely discarded.
MeSH terms: Adult; Aged; Uterine Cervical Neoplasms/diagnosis*; Uterine Cervical Neoplasms/ethnology; China/ethnology; Female; Humans; India/ethnology; Malaysia/epidemiology; Mass Screening/methods*; Middle Aged; Specimen Handling/methods*; Vaginal Smears/methods*; Reproducibility of Results; Young Adult; Papanicolaou Test*
Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.
MeSH terms: Animals; Cadaver; Crime*; Electron Transport Complex IV/analysis; Electron Transport Complex IV/genetics; Diptera/enzymology; Diptera/genetics*; Diptera/chemistry; DNA, Mitochondrial/analysis; Entomology/methods*; Humans; Larva/enzymology; Larva/chemistry; Leucine/analysis; Leucine/genetics; Malaysia; Phylogeny; RNA, Transfer; Time Factors; Genes, Insect; Crime Victims*; Forensic Pathology/methods*
Threatened miscarriage is a common complication of pregnancy. Despite initial viability confirmation by ultrasound scan, some of these patients had further spontaneous abortion. A highly sensitive and specific biomarker would be useful to determine the outcome of pregnancy and to prevent emotional impact to these women. A prospective 14-month cohort study was conducted in the Obstetrics and Gynaecology Department of Universiti Kebangsaan Malaysia Medical Centre to determine whether low serum levels of pregnancy-associated plasma protein A (PAPP-A) measured in early pregnancy can predict the outcome of threatened abortion. 42 pregnant women between 6 to 22 weeks of gestation with threatened abortion and 40 controls were enrolled. Serum samples were collected at presentation and PAPP-A was assayed by electrochemiluminescent immunoassay technique. Pregnancies were followed-up until 22 weeks of gestations and the outcome documented. Nine patients (11%) developed spontaneous abortion and 73 patients (89%) had successful pregnancy. The median PAPP-A level was significantly lower in patients with spontaneous abortion compared to those who had successful pregnancies in the threatened abortion group: 0.78 MoM (0.41-1.00 MoM) vs 1.00 MoM (1.00-2.0 MoM) respectively (p < 0.05). The best sensitivity of 44% and specificity of 93% were obtained at the cut of value of 0.66 MoM (95% CI, 0.561-0.773). In conclusion, low PAPP-A value in threatened abortion women is associated with pregnancy failure, although the use of PAPP-A as a one-time single marker has limited value.
Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. Leptospira is the aetiological agent of leptospirosis, a bacterial zoonosis with worldwide distribution. There are over 230 known serovars in the genus Leptospira. The true prevalence of leptospirosis in Malaysia is unknown or underestimated. Our goal was to determine the prevalence for Leptospira infection in rodents in a selected area in Beguk Dam Labis, Segamat, Johor. A study was carried out on 69 serum samples of trapped wild rodents. DNA was extracted from the sera using Leptospira PCR kit (Shanghai ZJ Bio-Tech Co., Ltd). Of 69 rodent serum samples tested by PCR, 9 (13%) showed positive results. In this study we found that (13%) of wild rodents caught in Beguk Dam Labis were infected by Leptospira.
The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-filled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in beta thalassaemia and haemoglobin E (HbE) individuals.