In this study, Li1+xAlxTi2-x(PO4)3 (0.0 ≤ x ≤ 0.5) was prepared by acetic acid-assisted sol-gel method. The structural properties of NASICON phosphates material with chemical formula LiTi2(PO4)3 were observed using the Fourier transform infrared spectroscopy. NASICON is a family of crystalline phosphate with a general network system consisting of PO4 tetrahedra, thus bands were assigned by vibrations contributed by basic phosphates, in the wavenumber region between 1300 cm-1 and 600 cm-1. Experimental spectra indicated that all Li1+xAlxTi2-x(PO4)3 (0.0 ≤ x ≤ 0.5), heat treated at 600°C and 700°C for 3 hours in air, samples showed the presence of phosphate peaks with shift in frequency as Al3+ is substituted into the structure, and with increasing temperatures. Some bands broadened and overlapped causing it hard to analyze the arising bands. It however determined the existence of NASICON structure in all of the samples under study.
Magnesium-based polymer gel electrolytes consist of magnesium triflate (MgTf) salt, a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) solvents as well as cellulose acetate as a polymeric agent were prepared via direct dissolution method. The highest ionic conductivity obtained for MgTf-EC:DEC(1:1) liquid electrolytes was 2.66 x 10-3 S cm-1 and enhanced to 2.73 x 10-3 S cm-1 with the addition of cellulose acetate. These results were in agreement with the activation energy obtained with the lowest value of 0.11. The best explanation on the enhancement in ionic conductivity of PGE is due to the “breathing polymeric chain model”. The plots of conductivity-temperature shown to obey an Arrhenius rule. The electrical properties of the sample with the highest conductivity were analyzed using electrical permittivity-based frequency and temperature dependence in the range of 100 Hz - 1 MHz and 303-373K, respectively. The variation in dielectric permittivity (εr and εi) as a function of frequency at different temperatures exhibited decays at higher frequencies and a dispersive behavior at low frequencies. Based on the observed electrical properties, it can be inferred that this polymer gel electrolyte could be a promising candidate as an electrolyte in electrochemical devices.
The coordination complexes of Co(II) and Zn(II) with Schiff bases derived from ophenylenediamine and substituted 2-hydroxybenzaldehyde were prepared. All compounds were characterized by Fourier transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) spectroscopy elemental analyzers. They were analyzed using impedance spectroscopy in the frequency range of 100Hz - 1MHz. L1 and L2 showed higher conductivity compared to their metal
complexes, which had values of 1.37 x 10-7 and 6.13 x 10-8S/cm respectively.
Six new Pd(II) and Ni(II) metal complexes of N, O-bidentate (L1, L2) and ONNO-tetradentate (L3) Schiff base ligands have been synthesized. The compounds were characterized via various physicochemical and spectroscopic techniques namely elemental analysis (CHN), FT-IR, 1H and 13C NMR as well as magnetic susceptibility measurement. All complexes showed diamagnetism indicating that they are square planar complexes. Catalytic performance of Pd(L1)2 and Pd(L2)2 were investigated for Heck cross-coupling reaction under optimum operating parameters, monitored using GC-FID for 6 h of reaction time in inert conditions. High catalytic activities of up to 90% were observed in the presence of triethylamine as base and DMA as solvent at 100oC with 1 mmol% catalyst loading. The mechanism of catalyzed Heck reaction is proposed to go through a series of conversion of Pd(0)/Pd(II).
Proteases were extracted from starfruit at maturity Index 2 (unripe, light green) and Index 7 (very ripe, orange) and partially purified using acetone and 40% ammonium sulfate precipitations. Higher yield and proteolytic activity were observed for proteases purified using acetone than 40% ammonium sulfate. As for maturity index, yield and protein concentration of proteases from Index 2 were higher than those from Index 7. SDS-PAGE result showed intense bands for acetone proteases while a distinct band at 50 kDa was observed in all the proteases. Enzyme activity decreased during the seven days storage at 4°C with minimum relative activity of 70% achieved for acetone proteases at day seven. This study suggested that acetone precipitation is more effective method for purifying starfruit protease based on the yield and proteolytic activity compared to using 40% ammonium sulphate precipitation. In order to obtain higher protein concentration and proteolytic activity, starfruit at the unripe stage, Index 2 is a better raw material than Index 7 to be used for protease production.
The invention of microarray technology has enabled expression levels of thousands of genes to be monitored at once. This modernized approach has created large amount of data to be examined. Recently, gene regulatory network has been an interesting topic and generated impressive research goals in computational biology. Better understanding of the genetic regulatory processes would bring significant implications in the biomedical fields and many other pharmaceutical industries. As a result, various mathematical and computational methods have been used to model gene regulatory network from microarray data. Amongst those methods, the Bayesian network model attracts the most attention and has become the prominent technique since it can capture nonlinear and stochastic relationships between variables. However, structure learning of this model is NP-hard and computationally complex as the number of potential edges increase drastically with the number of genes. In addition, most of the studies only focused on the predicted results while neglecting the fact that microarray data is a fragmented information on the whole biological process. Hence this study proposed a network-based inference model that combined biological knowledge in order to verify the constructed gene regulatory relationships. The gene regulatory network is constructed using Bayesian network based on low-order conditional independence approach. This technique aims to identify from the data the dependencies to construct the network structure, while addressing the structure learning problem. In addition, three main toolkits such as Ensembl, TFSearch and TRANSFAC have been used to determine the false positive edges and verify reliability of regulatory relationships. The experimental results show that by integrating biological knowledge it could enhance the precision results and reduce the number of false positive edges in the trained gene regulatory network.
Channel estimation techniques for Multiple-input Multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) based on comb type pilot arrangement with least-square error (LSE) estimator was investigated with space-time-frequency (STF) diversity implementation. The frequency offset in OFDM impacts its performance. This was mitigated with the implementation of the presented inter-carrier interference self-cancellation (ICI-SC) techniques and different space-time subcarrier mapping. STF block coding in the system exploits the spatial, temporal and frequency diversity to improve performance. Estimated channel was fed into a decoder which combines the STF decoding together with the estimated channel coefficients using LSE estimator for equalization. The performance of the system is compared by measuring the symbol error rate with a PSK-16 and PSK-32. The results show that subcarrier mapping together with ICI-SC were able to increase the system performance. Introduction of channel estimation was also able to estimate the channel coefficient at only 5dB difference with a perfectly known channel.
Crab meat is widely consumed in several countries around the world. However, when consumed, crab meat are frequent cause of allergic reactions throughout the world. Scylla serrata is among the most common mud crab in Malaysia. In a previous study two major allergens of mud crab at 36 and 41 kDa was identified. Thus, the aim of this study is to further identify these major allergens by a proteomic approach. Protein extract was prepared and resolved by 2-dimensional electrophoresis (2-DE). Immunoblotting was then performed using reactive sera from patients with crab allergy. Major allergenic spots were then excised from the 2-DE gel and analysed by mass spectrometry. The 2-DE profile of the extract revealed approximately >100 protein spots between pH of 4.00 to 8.00. Mass spectrometry analysis has identified the 36 and 41 kDa proteins as tropomyosin and arginine kinase, respectively. Our findings indicated that tropomyosin and arginine kinase play a major role in allergic reaction to mud crab meat among local patients with crab meat allergy, and should be included in diagnostics and therapeutic strategies of this allergy.
Primary angiitis of the central nervous system (PACNS) is a rare vasculitis restricted to the central nervous system without systemic involvement. Delay in diagnosis and treatment is common due to its non-specific symptoms and lack of non-invasive diagnostic tests. Myelopathy can occur in PACNS, during the clinical course of the illness, with or without cerebral symptoms. We describe here a 51 year-old ethnic Chinese woman who presented initially with paraparesis without cerebral symptoms. The diagnosis of PACNS was eventually made from brain biopsy when she subsequently developed cerebral involvement. Despite aggressive treatment, the patient developed progressive neurological deterioration and died. This patient demonstrates the rare occurrence of myelopathy as the sole initial presentation of PACNS.
MeSH terms: Biopsy; Brain; Central Nervous System; Diagnostic Tests, Routine; Female; Humans; Spinal Cord Diseases; Vasculitis, Central Nervous System; Paraparesis
Objective: To determine the incidence and predictors of early ankle contracture in adults with acquired brain injury. Methods: A prospective cohort study of patients admitted to Neurosurgical Intensive Care Unit (NICU), University Malaya Medical Centre and referred for rehabilitation within a period of 12 months. Adult patients with newly diagnosed acquired brain injury with no prior deformity to lower limbs, Glasgow Coma Scale ≤ 12, no concomitant spinal or lower limb injuries, medical stability at inclusion into the study and agreed to participate for the total duration of assessment (3 months) were recruited. We conducted weekly review of ankle muscle tone and measurement of ankle maximum passive dorsiflexion motion. The end point is reached if ankle contracture developed or completed 3 months post injury assessment. Results: The cohort included 70 patients, of which only 46 patients completed the study. Twenty-eight patients suffered from severe brain injury whilst 18 from moderate brain injury. Out of the 46 patients, 13 (28%) developed ankle contracture at the end of the study period. Abnormal motor pattern was significantly associated with incidence of ankle contracture, which included spasticity (p
Cranial encephaloceles are rare conditions, which are more commonly seen in the anterior rather than in the middle cranial fossa. Temporal lobe encephalocele can present with a variety of clinical symptoms, amongst which include occult or symptomatic cerebrospinal fluid (CSF) fistula. We present a case of a patient with a short history of rhinorrhea who was found to have a CSF pool in the sphenoid sinus and right anteromedial temporosphenoidal encephalocele, which mimics sphenoid mucocoele, a much more common entity. This case highlights the imaging findings of temporosphenoidal encephalocoele and the diagnostic clues in differentiating this rare condition from the commoner mimics.
Thrombosis of the deep cerebral venous system in the absence of superficial sinus thrombosis is a very rare disease. The clinical and radiological findings can be diagnostically challenging due to the subtle appearances on computed tomography (CT) scan. Magnetic resonance imaging (MRI) examination is a preferred imaging modality to complement the CT findings for an accurate diagnosis of venous sinus thrombosis. We present a case of this unusual condition which present as unilateral thalamic lesion on CT scan and the role of contrast enhanced MRI with fast spoiled gradient echo (FSPGR) sequence and 3D reconstruction which led to the diagnosis of thrombosis in the deep cerebral venous system.
Background& Objective: Investigation modalities, such as MRI and CSF examination, are neither sensitive nor specific in the early phase of anti-NMDAR encephalitis. Nuclear imaging may be useful to monitor the response to treatment but limited by the availability.We aimed to determine the role of EEG as a tool for early diagnosis as well as a tool to assess disease progression and response to treatment. Methods: A total of 99 EEGsdone in 16 patients diagnosed with anti-NMDAR encephalitis throughout the course of illness, were reviewed retrospectively. The EEG changes were correlated with the clinical presentations and response to treatment. Sixteen EEGs of patients with schizophrenia and mood disorder, and 10 EEGs of patients with infective encephalitis were included as control. Results: EEGs performed during the psychiatric and cognitive dysfunctionphase in patient with anti-NMDAR encephalitis, showed diffuse background slowing in the delta-theta range in all the patients. Serial EEGs showed that the dominant background frequency improved with improvement in cognitive status. Nine patients had complete recovery with normalisation of the EEG abnormalities. Eight patients had their typical clinical seizure recorded during EEG monitoring, but only 2 (25.0%) with EEG correlation. Ten patients had status epilepticus (62.5%), 5 had EEG recorded during their status epilepticus, of which only one with EEG correlation (20.0%). Eleven patients had asymmetric background (68.8%), but only 1 has correlation with focal changes in the MRI brain (9.1%). Even though the EEGs of patients with infective encephalitis also showed background slowing, their CSF analysis was supportive of an infective cause. EEGs of patients with established psychiatric disorder were within normal limits.
Conclusion: EEG abnormality has a good correlation with the degree of psychiatric and cognitive dysfunction in patient with anti-NMDAR encephalitis, and is useful in early diagnosis, monitoring the progress and the response to treatment. However, it has poor correlation with clinical seizures.
MeSH terms: Adolescent; Adult; China/ethnology; Electroencephalography; Female; Humans; Magnetic Resonance Imaging; Malaysia; Malaysia/ethnology; Male; Retrospective Studies; Schizophrenia; Seizures; Status Epilepticus; Disease Progression; Mood Disorders; Early Diagnosis; Anti-N-Methyl-D-Aspartate Receptor Encephalitis
Objective: To delineate and differentiate between late subacute hemorrhage and intracranial lipomas in clinically available conventional and advanced MR sequences. Methods: Two cases of late subacute hemorrhage and two cases of intracranial lipoma were reviewed with CT scans and 3.0T scanner MRI. The sequences evaluated in MRI were T1-weighted (T1W) fast spin echo (FSE), T2-weighted (T2W) FSE, gradient echo T2*-weighted (GRE T2*W) images, diffusion weighted (DWI), apparent diffusion coefficient (ADC) and multivoxel spectroscopy. Results: Late subacute hemorrhage and intracranial lipoma have similar imaging features on T1W, T2W FSE with blooming artefact at the margins on GRE T2*W. However on GRE T2*W sequence, the central area of lipoma demonstrates low signal; while hemorrhage demonstrates high signal. In DWI, late subacute hemorrhage shows hyperintensity; while in lipoma there is loss of signal.
Conclusion: Awareness of the potential pitfalls in standard sequence are important, as these entities appear to have similar T1W/ T2W characteristic with blooming artefact on T2*W. Knowing the distinctive central signal intensity pattern on GRE T2W* and DWI is therefore essential to differentiate between these lesions as there are differences to their clinical management.
Background & Objectives: The burden of stroke is increasing, in part due to increasing prevalence of diabetes mellitus. Given the high prevalence of diabetes in the Malaysian population (22.6%), we aimed to determine the prevalence of diabetes in our stroke population. We also aimed to study the stroke subtype associated with diabetes. We hypothesized that lacunar infarction would be more prevalent in diabetics. Methods: We retrospectively reviewed data of consecutive patients with acute ischaemic stroke admitted from October 2004 to December 2010 from our stroke registry. Demographic data, risk factors profile and stroke subtypes were reviewed and analyzed. Results: Eight hundred and fifty eight patients were identified from the registry. As high as 59.3% (n=509) of our patients were diabetics, of which 49.2% (n=422) had pre-existing diabetes and 10.1% (n=87) were newly diagnosed. Lacunar infarction was the commonest stroke subtype, comprising 60.6% (n=519) of all strokes. Diabetes was significantly associated with lacunar infarction (OR 1.5, CI 95% 1.16-2.01, p=0.003), particularly in those aged ≤ 55 years (OR 2.29, 95% CI 1.12-4.67) and HbA1C ≥ 6.5% (χ2=8.77, p=0.003). Conclusions: The prevalence of diabetes in our stroke patients is amongst the highest reported. Diabetes mellitus, particularly those with poor glycaemic control is strongly associated with lacunar infarction.
The term “anti-epileptic drug” refers to the currently available medical treatment against epilepsy. A discussion amongst the authors was sought to critically examine the term and identify possible issues. Translations in other languages were retrieved from literature and the usage confirmed by correspondence with native users of the language working in the medical field. The aim of this article is to initiate a debate by highlighting some negative undertones attached to this terminology.
Childhood brain injury is an important and complicated public health issue worldwide. Extensive work has been done in this field. This review highlights issues that are frequently misinterpreted or overlooked in the management of childhood brain injury. The incidence of traumatic brain injury is higher than non-traumatic brain injury. However it is frequently over-reported due to various confounding factors. In ascertaining the severity of injury, assessment of brainstem functions is important and should be included in routine clinical assessment. Most rehabilitative efforts are usually aimed at improving the physical outcome. However, non-physical sequelae are also common and may be more disabling with significant impact on the learning and functioning of the child. These areas, which include depression, cognitive functioning and health-related quality of life of children, should not be overlooked in the management of childhood brain injury. In addition to caregiver’s stress, family dynamic and siblings’ well-being also play a crucial role in the recovery process of the child. By highlighting the frequently missed issues in the management of childhood brain injury, it is hoped that clinicians and professionals could pay more attention to these issues and provide a comprehensive medical care for the patients and their families.
MeSH terms: Attention; Brain Injuries; Brain Stem; Child; Cognition; Depression; Depressive Disorder; Family Relations; Humans; Learning; Public Health; Quality of Life; Incidence; Caregivers; Siblings; Hope
Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) analysis were performed in this work in order to obtain the best design for safety and aerodynamic performance of the bicycle cycling helmet. FEA analysis was computed on two different helmet designs to determine the critical area subjected to impact. A pressure load was applied on the helmets’ outer surface to simulate oblique loading. The critical areas of the helmets were then highlighted and identified, enabling design improvements to be made on both designs. CFD analysis was then executed in order to obtain the lowest drag coefficient number in reducing the air resistance induced by both of the helmet designs, inherently increasing cyclist performance and ensuring competition success.
MeSH terms: Bicycling; Head Protective Devices; Pressure; Safety; Work; Finite Element Analysis; Biochemical Processes; Hydrodynamics
This study aims to examine the decision making by rugby sevens referees, and its relationship with the referees' performance. The instruments used in this study are the Rugby Referee Decision Making Test (α=.74) and the Referee Sevens Field Performance Evaluation (α=.94). It was administered to 132 rugby sevens referees (mean age 33.4 + 1.5 years; 132 males) from the Malaysian Rugby Union (MRU), which have been refereeing in 10 rugby sevens tournaments in Malaysia. Descriptive and Inferential statistics (one way ANOVA and Pearson's Correlation) were employed to analyse the data. Decision Making ( ̅= 24.13, SD=5.24) and performance ( ̅= 136.45, SD = 4.47) were identified at a moderate level. The findings indicated no significant differences [F= (3, 128) =.246, p>0.05] in the decision making across age level, but there were significant differences [F= (3, 128) =63.159, p
The beneficial impact of the differential biofeedback intervention technique on modification in autonomic competence, as well as the ultimate impact on bilateral shooting ability, were studied on young and competitive male soccer players. A total of 45 young high-performing soccer players in the age range of 18 to 24 years were recruited. At first, the players were subjected to baseline evaluation of psychomotor (i.e., reaction time - RT), physiological (viz. resting heart-rate; VO2Max, electrical muscle potentiality, etc.), and psychobiological indices (such as skin conductance components - latency, amplitude and recovery time). Thereafter, they were equally categorized into: Control Group, Experimental Group I [who received skin conductance (Sc) biofeedback training], and Experimental Group II [who received electromyography (EMG) biofeedback intervention training]. Participants of the experimental groups were subjected to their respective interventions (Sc & EMG biofeedback intervention training), which were imparted for 24 sessions (15 mins/day; 2 days/week for 12 weeks). After six weeks of intervention, mid-term evaluation of all of the aforementioned parameters (assessed during baseline evaluation) was performed. Thereafter, intervention sessions continued following the identical protocol for six weeks. At the end of the 12th week, a post-intervention assessment on all of the psychological, psychomotor and psychobiological variables was carried out on all of the participants to verify the effect of training on dependent measures. Post-intervention analyses revealed improvements in physiological, psychobiological and performance parameters, which could be rationally attributed to the differential biofeedback therapeutic interventions introduced to the experimental groups. The outcome suggested that both interventions facilitated improvement in bilateral shooting ability, while indepth analyses clarified that a higher extent of autonomic recovery emerged as the most significant factor facilitating shooting ability in the experimental groups.