The objective of the study was to asses the adhesion of Streptococcus mutans on nanofilled and microfilled composite resin and glass ionomer cement restorative materials. Glass ionomer cements; KetacTM N100 (nanofilled) and Fuji IITM LC (microfilled) and composite resins; FiltekTM Z350 (nanofilled) and FiltekTM Z250 (microhybrid) were packed in acrylic mould of 2 mm thickness and 5 mm diameter. All samples were light-cured and polished with Sof-Lex discs. All materials were cultured with the exponential phase of S. mutans cultivation. Surface roughness values were assessed using Atomic Force Microscope (AFM, Ambios, USA) at time intervals (7hrs, 24 hrs, 7 days, 14 days and 21 days). The morphology of S. mutans on materials was observed after 24 hour incubation of S. mutan on materials under Scanning Electron Microscope (SEM, Quanta FEG 450). Within groups, results showed that both nanofilled materials had lower surface roughness and less adhesion of S. mutans compared to microfilled materials. This study would enhance the clinical knowledge especially in aesthetic area and improve the longevity of the dental restoration.
The objective of the present study is to evaluate the effect of incorporation of 3- acetylcoumarin (3-AC), an antibacterial agent, on the mechanical and surface morphology of glass ionomer cement (GIC). A conventional GIC, Fuji II LC, was used as a control. 3-AC was incorporated into GIC during its manipulation at percentage of 2% and 5% (wt/wt). Flexural strength of the specimens were analysed using Shimadzu AGX-Plus while morphological evaluation of the specimens were observed using Scanning Electron Microscope (SEM). Oneway analysis (ANOVA) with post-hoc Bonferroni multiple-range test was used to determine the significant differences among the groups. Statistically, the incorporation of 2% (wt/wt) of 3-AC into GIC showed a significantly lower flexural strength (p
Silicon dioxide (SiO2) has been extensively studied due to their unique properties that make it desirable for many applications ranging from electronic, catalysis, pigment as well as sensors. Multitude of methods and processes are established with the ability to manipulate and control the key properties that can cater for specific applications. Stober method is a very simple and easy for up-scale production of SiO2. This paper presents the experimental study on the effect of synthesis parameter on the morphology of SiO2 synthesized via Stober method. Three parameters were investigated such as concentration of catalyst, concentration of precursor and percentage of water content. The obtained samples were characterized using scanning electron microscopy (SEM) analysis. The findings showed that the size of particles produced is dependent on the synthesis parameter. In this study, particles size ranging from 50 nm to >100 nm are easily produced. The sphere size of SiO2 can be increased by increasing the concentration of ammonia hydroxide catalyst, the concentration of TEOS, as well as the percentage of water content.
Acanthaster planci, a marine starfish is a major management issue on geochemical signatures coral reefs. Attempts to tap into the vast potential of these marine invertebrates as exploitable innovative sources of bioactive metabolites that may or can be directly utilized as drugs or serve as lead structures for drug development and neutraceuticals have been intensified. Such probing effort are based on purported reports and folk medicine that indicate most of these exploitable marine based natural products are believed to be mainly accumulated in most local iconic geochemical signatures marine invertebrates’ biomass such as within the echinoderm, sponges, tunicates, bryozoans, and molluscs. However, little is known on local Malaysia Acanthaster planci or crown of thorns (COTS) biomass actual inert biocompounds profile and its related tangibilities, for a sustainable commercial optimization and exploitation in health related agendas or therapeutic application. This manuscript will thus highlights present research efforts of pertinent to local Malaysia geochemical signature invertebrates Acanthaster planci‘s potential from a once wasted predator biomass to as this said millennium, wealth generated medical and pharmaceutical-therapeutics’ development targeted agenda.
The effect of alginate concentration on the mechanical properties of hydroxyapatite (HAp) scaffold was investigated in this study. Sodium alginate solution with concentration 1%, 3% and 5% was prepared through the neutral extraction of cultivated Sargassumpolycystum brown seaweed. HAp scaffold was prepared via polymer reticulate method and sintered at 1250 ̊C. HAp scaffolds were then immersed in sodium alginate solution at 1%, 3% and 5% concentration under vacuum. FTIR spectra show that the extracted sodium alginate has the same functional groups as in commercial sodium alginate. Compressive strength increased as the sodium alginate concentration increased. Morphology observation shows that the micro cracks on the struts were covered by alginate. The increase in the compressive strength is due to the coverage of the cracks on the struts by sodium alginate.
Porous ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. In this study, porous hydroxyapatite (HA) was produced via polymer replication method. Polyurethane (PU) sponge was selected as the template and synthetic binder, polyvinyl alcohol (PVA) was used in this study. Fixed formulation of HA powder, distilled water and PVA (40:60:3) were prepared and stirred at a constant 4 hours time. PU sponges with 30 ppi and 60 ppi size were cut and impregnated in slurry using vacuum and roller infiltration methods. The microstructures were observed by using field emission scanning electron microscope (FESEM). The results obtained indicate that vacuum infiltration method and 60 ppi template pore size exhibited the highest compressive strength with moderate average strut thickness and lowest average pore size compared to samples produced by roller infiltration method at different template pore size.
MeSH terms: Bone and Bones; Ceramics; Microscopy, Electron, Scanning; Polymers; Polyurethanes; Polyvinyl Alcohol; Vacuum; Porosity; Durapatite; Bone Substitutes; Compressive Strength; Tissue Engineering
Sol-gel barium titanate (BaTiO3) and erbium doped barium titanate (Er-BaTiO3) were deposited on SiO2/Si substrates. The phase and crystallinity of the thin films were identified using x-ray diffractometer (XRD). The effect of Er dopant into BaTiO3 thin film on its grain size and surface roughness was studied using atomic force microscope (AFM) in tapping mode. XRD patterns revealed that the films were crystallized with perovskite structure. At the same time, it was shown that introducing Er dopant into BaTiO3 thin film caused the dominant peak to shift towards higher angle. AFM micrographs indicated that the films had well distributed grains, dense and crack-free surface. In general, substitution of Er dopant into Ba-site reduced the grain sizes and roughness parameter of the BaTiO3 which was attributed to the smaller ionic radius of Er.
Glass-ceramics are a group of materials that takes advantage of the various glass-forming methods before they are subsequently heat-treated in a controlled manner to effect nucleation and crystallization to produce crystalline materials. The production of glassceramic materials is to overcome the low mechanical strength in pure glassy materials. In this work, a study on the crystallisation of a soda-lime-silica glass was undertaken to ascertain how the processing parameters affect the crystallization of such glasses, viz. either via a single or two-step heat-treatment procedure, as well as the effect of soaking duration at the heat-treatment temperature. A soda-lime-silica glass system was chosen because the raw materials for producing such glasses are readily available and can be considered to be the cheapest. The glass produced was examined by thermal analysis to determine the nucleation and crystallization temperatures before they were heat-treated using a single-step and a two-stage heat-treatment procedures. The resultant glassceramics produced were characterized using x-ray diffraction as well as by scanning electron microscopy. The results thus obtained showed that a two-stage heat-treatment procedure is more successful in producing a well-crystallized glass-ceramic product.
Neoculin is a sweet protein capable to alter the sour taste into sweet taste, it is 500 times sweeter than the ordinary sugar. This protein has been discovered in Malaysia under the name of Curculin. There are a number of experimental studies that have been conducted on neoculin but none of the studies focuses on molecular level, in order to understand how the protein interacts with the human sweet taste receptors T1R2 and T1R3. Therefore, in this work, a protein-protein docking study was performed between neoculin and the human sweet taste receptor T1R2 and T1R3. The docking results showed residues that might be important for binding the neoculin with the human sweet taste receptors, particularly T1R3 at the amino terminal domain (ATD). In addition, the current results showed that His11, which is important for the taste modifying ability does not bind directly to the human sweet taste receptors.
This paper presents an experimental investigation on the effects of sintering temperature to the mechanical properties and microstructures of FeCrAl powder compacts formed through warm powder compaction route. Elemental iron powder ASC 100.29, copper and aluminum powder were blended mechanically in a low speed mixer. The blended powder mass was compacted at a temperature of 200°C and was later sintered in an argon gas fired furnace by varying the sintering temperature, i.e., 600°C, 750°C and 900°C for 90 minutes. The sintered products were then subjected to density measurement, flexure strength measurement as well as microstructure analysis through scanning electron microscopy. The results revealed that the suitable sintering temperature is 600°C which generated light weight products with higher bending strength, lower volumetric expansion, and better microstructure.
Biofilm complicates osteomyelitis as there is antibiotic resistance and toxicity involved. In order to overcome the challenges of current treatment, gentamicin, the current antibiotic of choice for osteomyelitis, is fused with Nigella sativa oil to form an emulsion. Its efficacy as anti-biofilm agent is assessed using confocal laser scanning microscope (CLSM) against different strains of biofilm-producing Staphylococcus aureus. These strains of S.aureus were first allowed to express biofilm before being exposed for 24 hours to the emulsion with (0.1% (w/v) gentamicin; 40.2% (v/v) N.sativa. Later, the emulsion was removed and the biofilm was stained with fluorescence staining. The slides were viewed under CLSM at 100 times resolution. 3D images of biofilm were reconstructed, using Image J software, to measure the thickness of biofilm and viability of bacteria cells. Results revealed that the emulsion significantly reduced biofilm thickness compared to gentamicin and N.sativa alone in all strains of S.aureus (Tukey’s test p < 0.05). The emulsion was also able to produce more than 80% and 15% surface percentage (%) of non-viable (dead) bacteria in the sensitive and resistant strain, respectively, at a significant level when compared to gentamicin and N.sativa (Tukey’s test p < 0.05). As a conclusion, this new fusion of gentamicin-N.sativa may be effective towards the biofilm of S.aureus, and can be developed further as a new promising anti-biofilm agent in osteomyelitis.
Incineration and disposal of carbon fiber waste from the aircraft industry lead to serious energy consumption and environmental pollution. The use of this waste as reinforcement is a wise approach to appreciate the high performance of the carbon fiber. This study is part of our effort to develop new green rubber foam from recycled carbon fiber prepreg (rCFP) reinforced natural rubber via internal mixer. It is focusing on the effect of different rCFP loading at 1, 3, 5, and 7 parts per hundred rubbers (phr) as reinforcement. The samples were prepared by melt compounding using an internal mixer and expanded via two step heat transfer foaming process. The physical properties of the green rubber foam were characterized and the results were observed to systematically correlate with the impact properties of the foam. The absorbed energy of the foam increases up to 0.3 joules with increasing relative foam density of 0.81 which is associated with the formation of smaller foam cells ~0.68mm and more spherical shape pores.
Current study report the growth of Zinc Oxide (ZnO) nanorods (NRs) by a facile and low temperature method on Zinc (Zn) foil in deionized (DI) water. These ZnO NRs have a typical length of 500-700 nm and average diameter of 50-70 nm. By using different volume of DI water, the morphology of ZnO nanostructures are tunable from rod-like to flower-like structures. Under the presence of Zn nitrate precursor, mixture of rod/wall-like structures are formed. Both of ZnO NRs and combined nanorods/nanowalls render higher diffraction for the (002) peak reveals, which implies preferred orientation growth along c-axis take place. However, photoluminescence (PL) study indicates that ZnO NRs have strong emission located at ~380 nm if compared to that of combined ZnO nanorods/nanowalls. This shows that ZnO NRs have higher-densities of defects.
Pollen distribution from the pollen loads of stingless bee foragers in KampungTempinis, Besut, Terengganu was observed and recorded using optical microscope. Heterotrigona itama, one of the most common IndoMalayan stingless bee species domesticated and widely distributed throughout Malaysia was selected for this observation.The objective of this study was to have an annual bee calendar for H. itama in Besut. Pollen collection was carried out twice a month from January to June 2015. Results showed, during the six months period of observation H. itama foraged 31 different flowering plants. Different months of the year showed different floral preference by the stingless bee. The most dominant flower visited by the stingless bee in January and February is Stevia rebaudiana while March to June is Antigonon leptopus (Honolulu creeper). This observation could be useful for conservation purposes and also in planning a good beescape in Malaysia meliponiculture industry.
Aims: To review the psychosocial risk factors for colorectal cancer (CRC),
report the types and explore their association with CRC.
Methods: We
followed PRISMA guidelines to conduct the systematic review. We searched
electronic databases (PubMed, CINAHL, PsychINFO and EMBASE) and
hand searched up to 15th April 2015 for studies on psychosocial or stress or
depression or anxiety or personality or support or coping as risk factor for
CRC. We extracted information about the place of the study, study design,
measurement tools, participant’s characteristics, psychosocial risk factor and
its association with CRC. We limited the studies in English language only.
The findings were synthesized and analysed. We presented them in tables
and text.
Results: We identified eight research papers which met the criteria.
The studies reported four different types of psychosocial factor i.e.
personality, stress, anxiety and depression. Four studies explored on
personality, two on stress, one on anxiety and one on depression. There were
four case-control studies and three longitudinal prospective studies. Two of
the studies showed a significant association between personality and risk of
CRC and two studies reported otherwise. Aggressive-hostility personality
and negative emotions were significantly associated with risk of CRC. One
study reported high level of job stress, higher anxiety levels and high level of
depressive symptoms in females was also associated with increased risk of
CRC. However, one study showed a lower risk of CRC in highly stressed
females and no clear relationship between stress and risk of CRC in men.
Conclusion: There is still inconclusive evidence to show that psychosocial
factors are risk for colorectal cancer.
Objective: Wilson’s disease (WD) is a rare disorder of copper metabolism
with hepatic, neurological and psychiatric manifestations. This case describes
insomnia as a rare primary psychiatric presentation of WD.
Methods: An 18
year old gentleman presented with three months of poor sleep. There was no
depressive, manic, psychotic, anxiety or cognitive symptoms. He was
diagnosed with WD three months ago. Physical examination was normal
however Kayser-Fleischer rings were noted. MRI brain demonstrated
symmetrical signal abnormalities noted in the head of the caudate nucleus,
putamen and globus pallidus. His insomnia worsened on increased dose of
chelating agent so the agent was reduced. Longitudinally he developed
depressive symptoms so has been commenced on mirtazapine.
Discussion:
Psychiatric complications of WD are found in initial presentation in 30-67%
cases. Underlying scientific mechanisms proposed include brain copper
toxicity, presynaptic SERT availability, and alternative metabolic influences.
Treatment focuses on chelating agents and psychotropic augmentation.
Introduction: Grief may be complicated in patients with dementia, posing a challenge to caregivers and healthcare professionals. A case of major vascular neurocognitive disorder with pathological jealousy and major depressive disorder in grief is reported.
Case: A 73 year-old Malay lady with diabetes mellitus, hypertension, dyslipidemia, and right cerebrovascular
accident developed major vascular neurocognitive disorder with pathological jealousy and major depressive disorder. She presented with unmanageable agitation and depression after her late husband’s death. She also experienced
a bizarre delusion of her husband’s resurrection and infidelity. Her psychotropic medications were optimised and her bizarre delusion was challenged daily using validation and distraction techniques. Combined pharmacotherapy and behavioural therapy managed to resolve her psychiatric symptoms and facilitate her grief process.
Conclusion: Grief reaction in major vascular neurocognitive disorder patients is often atypical. Individualized treatment comprising both pharmacotherapy and behavioural therapy should be offered to treat atypical grief and the underlying disease.
The authors report a case of co-morbid diagnosis Anorexia Nervosa (AN) with co-morbid diagnosis of Obsessive-compulsive Disorder (OCD) by proxy. The patient is a 16-year-old female who presented to the emergency department with features of AN and also OCD. To reduce the anxiety of her AN, she incorporated her mother as a proxy to follow specific instructions. The patient received both inpatient and outpatient support, and her condition gradually improved with antidepressants and antipsychotics. This case illustrates a co-morbid presentation of OCD with AN and also the result of family accommodation that led to the family member aiding with the compulsion. Treatment for the case was also briefly discussed.
Study site: emergency department (unspecified)
Introduction: Korsakoff Syndrome (KS) is a preventable memory disorder
that can occur after Wernicke’s encephalopathy (WE). There is scarce
information regarding KS in Malaysia. Method: Case report. Results: A 49
year-old Chinese lady with daily alcohol use in between 15-20 units for more
than 10 years became forgetful eight months prior to her admission due to
withdrawal symptoms and a fall when she attempted to cut down her alcohol
use to 7–8 units. Examination revealed confabulation, dysdiadochokinesia,
resting and intentional tremor but not confusion, ophthalmoplegia,
nystagmus or ataxia. Mini mental state examination result was 14/30.
Investigations revealed features of chronic alcohol use and cerebral atrophy
of bilateral frontotemporal lobe. Despite aggressive treatment with
intravenous and oral thiamine, the patient’s cognitive deficit persisted. Hence
KS was diagnosed. Discussion: There is no proven treatment that can
reverse KS other than prevention. Thiamine fortification may be
implemented locally to prevent this condition.
Objective: This systematic review is aimed to quantitatively summarise the
prevalence of sexual dysfunction among non-SSRI second generation
antidepressants namely agomelatine, bupropion, duloxetine, venlafaxine, and
mirtazapine.
Methods: Relevant studies published from inception till
December 2012 were identified by searching PubMed, OVID and Embase.
We included all literatures encompassing randomized controlled, cohort,
case-controlled and cross-sectional studies, which contained quantitative data
for prevalence on all aspects of sexual dysfunction in depressive patients who
were older than 18 years of age. Heterogeneity, publication bias and odds
ratio were assessed thoroughly.
Results: In the non-SSRI second generation
antidepressant group which consisted of 17,316 subjects, various studies
showed the range of sexual dysfunction prevalence between 0% and 67%.
Sexual dysfunction in patients who took non-SSRI second generation
antidepressants constituted a meta-analytical pooled prevalence of 15%, and
36% in those who took SSRIs. The combined relative risk of sexual
dysfunction in the non-SSRI second generation antidepressant group when
compared with SSRI was 0.57.
Conclusions: The pooled prevalence of sexual
dysfunction in non-SSRI second generation antidepressant is lower than in
SSRI antidepressants.