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Fulltext An audit of the turnaround time of fixed prosthodontics cases in the ceramic laboratory

Khan, A., Mohd Noor, N.S., Sukumaran, P., Sheikh Aladin, S.H.A., Wai Ying, Y.

Ann Dent, 2016;22(2):1-8.
MyJurnal

This clinical audit is aimed to provide an insight into the performance of dental technicians in rendering
fixed prosthodontics services at Faculty of Dentistry, University of Malaya. A retrospective audit was
carried out between 1st of November 2014 and 31st January 2015 using data derived from records and
monthly returns of the technicians, which are kept at the ceramic laboratory. Retrospective data on
cases of diagnostic wax-ups, full metal crowns, metal ceramic crowns, all ceramic crowns and bridges
that were sent to ceramic laboratory for fabrication from 1st of September 2013 to 31st of August 2014
was systematically extracted from the record and tabulated categorically in SPSS version 22.0. The
turnaround time in workings day for diagnostic wax-ups and the prostheses was calculated by deducting
exit date from entry date. Subsequently, the turnaround time and the complexity of cases were categorized
accordingly. The association of turnaround time and the complexity of the cases was analysed using
Fisher Exact test with p value < 0.05. Within this time frame, a total of 102 cases of diagnostic waxups,
36 cases of crown and 18 cases of bridges were fabricated. 57.8% of diagnostic wax-ups were
completed within 3 days. 100% of 1 unit crown were completed within 7 days and 94.4% of bridges were
completed within 14 days. There was a significant association of turnaround time and the complexity of
the cases for diagnostic wax-ups and crowns with p value

Matched MeSH terms: Metals
Fulltext Occupational safety and health assessment in metal industry within small and medium enterprise

Siti Suhaili Shahlan, Mimi H. Hassim, Kamarizan Kidam, Haszlee Mohd Safuan, Norasikin Othman, Adnan Ripin, et al.

Journal of Occupational Safety and Health, 2015;12(1):81-84.
MyJurnal

According to annual reports from the Social Security Organization (SOCSO), between years 2009 and 2011,
metal industry has the highest reported number of accidents compared to the other manufacturing industry in small
and medium enterprises (SMEs). Therefore, the aim of this study was to investigate the actual causes of problems that
lead to the accidents involving metal industries within SMEs. In this study, a checklist through site visits was used to
collect the data. The overall results revealed that the main causes of accidents are; organization failure, human factor,
machine failure and surrounding environments.

Matched MeSH terms: Metals
Fulltext Cu-Ni alloys coatings for corrosion protection on mild steel in 0.5 M NaCl solution

Mohammad Hafizudden Mohd Zaki, Yusairie Mohd, Nik Norziehana Che Isa

Science Letters, 2016;11(2):20-29.
MyJurnal

Mild steel is the most common metal used in industry. However, mild steel easily corrodes when exposed to environment. One way to protect mild steel from corrodes is by coating it with more noble metal like copper and its alloys. In this study, copper and Cu-Ni alloys were successfully coated on the mild steel substrate by electrodeposition technique using alkaline citrate solutions containing Cu and Ni ions precursors. The reaction and mechanisms of the electrodeposition of copper and Cu-Ni alloys on the mild steel substrate were investigated by cyclic voltammetry and chronoamperometry methods. Surface morphology of the coatings was examined by FESEM. The elemental compositions of the coatings were confirmed by EDAX analysis. The molar ratios of Cu-Ni solutions have affected the formation of the coatings. Corrosion study shows that copper coated mild steel can improve the corrosion resistance of the mild steel in 0.5 M NaCl. Cu-Ni coating prepared from Cu60-Ni40 showed the highest corrosion resistance. The order of the corrosion resistance of the samples in 0.5 M NaCl at 25 oC is Cu60-Ni40> Cu75- Ni25> Cu90-Ni10> Cu100> mild steel.

Matched MeSH terms: Metals
Fulltext Radiation damage in the silicon dioxide (SiO2) layer

Chee, Fuei Pien, Saafie Salleh, Afishah Alias, Haider F. Abdul Amir, Abu Hassan Husin

Journal of Nuclear and Related Technologies, 2017;12(2):81-87.
MyJurnal

The most sensitive part of a metal-oxide-semiconductor (MOS) structure to ionizing radiation is the
oxide insulating layer. When ionizing radiation passes through the oxide, the energy deposited creates
electron/hole pairs. Oxide trapped charge causes a negative shift in capacitance-voltage (C-V)
characteristics. These changes are the results of, firstly, incre using trapped positive charge in the
oxide, which causes a parallel shift of the curve to more negative voltages, and secondly, increasing
interface trap density, which causes the curve to stretch-out.

Matched MeSH terms: Metals
Fulltext Minimum intervention dentistry with indirect fibrereinforced composite bridge: a case report

Yanti Johari, Zaihan Ariffin, Haslina Taib, Norehan Mokhtar

Archives of Orofacial Sciences, 2016;11(2):49-53.
MyJurnal

Resin-bonded fibre-reinforced composite bridges provide many advantages over the conventional
bridges or implant treatment in the management of a traumatically or congenitally missing anterior tooth.
Furthermore, there is an increasing demand towards providing a metal free resin-bonded bridges over the alloybased
restorations in order to meet the aesthetic needs especially in the anterior region. Advances in the
adhesive technology and tooth colored materials offer improved bonding system and better aesthetic outcome.
Nevertheless, careful selection of cases to receive this type of approach is also one of the key factor to ensure
the clinical survival of fibre-reinforced composite bridges. This report aims to present the use of fibre-reinforced
composite to construct indirect cantilever fibre-reinforced composite bridges as part of minimum intervention
dentistry.

Matched MeSH terms: Metals
Graphene/transition metal dichalcogenides hybrid supercapacitor electrode: status, challenges, and perspectives

Seman RNAR, Azam MA, Ani MH

Nanotechnology, 2018 Dec 14;29(50):502001.
PMID: 30248022 DOI: 10.1088/1361-6528/aae3da

Supercapacitors, based on fast ion transportation, are among the most promising energy storage solutions that can deliver fast charging-discharging within seconds and exhibit excellent cycling stability. The development of a good electrode material is one of the key factors in enhancing supercapacitor performance. Graphene (G), an allotrope of carbon that consists of a single layer of carbon atoms arranged in a hexagonal lattice, elicits research attention among scientists in the field of energy storage due to its remarkable properties, such as outstanding electrical conductivity, good chemical stability, and excellent mechanical behavior. Furthermore, numerous studies focus on 2D materials that are analogous to graphene as electrode supercapacitors, including transition metal dichalcogenides (TMDs). Recently, scientists and researchers are exploring TMDs because of the distinct features that make 2D TMDs highly attractive for capacitive energy storage. This study provides an overview of the structure, properties, synthesis methods, and electrochemical performance of G/TMD supercapacitors. Furthermore, the combination of G and TMDs to develop a hybrid structure may increase their energy density by introducing an asymmetric supercapacitor system. We will also discuss the future prospect of this system in the energy field.

Matched MeSH terms: Metals
Fulltext Preliminary screening of plant proteases as a potential source for the development of an inhibitive assay for heavy metals

Gunasekaran, B., Johari, W.L.W., Wasoh, M.H., Masdor, N.A., Shukor, M.Y.

Bioremediation Science and Technology Research, 2018;6(1):9-13.
MyJurnal

Heavy metals pollution has become a great threat to the world. Since instrumental methods are
expensive and need skilled technician, a simple and fast method is needed to determine the
presence of heavy metals in the environment. In this work, a preliminary study was carried out
on the applicability of various local plants as a source of protease for the future development of
the inhibitive enzyme assay for heavy-metals. The crude proteases preparation was assayed using
casein as a substrate in conjunction with the Coomassie dye-binding assay. The crude protease
from the kesinai plant was found to be the most potent plant protease. The crude enzyme
exhibited broad temperature and pH ranges for activity and will be developed in the future as a
potential inhibitive assay for heavy metals.

Matched MeSH terms: Metals, Heavy
Evaluation of Microleakage Between Different Post and Core Systems Under Gradual Loading: an In-Vitro Study

Salim NA, Muttlib NAA, Alawi R, Rahman NA, Ariffin Z

Acta Stomatol Croat, 2018 Sep;52(3):218-226.
PMID: 30510297 DOI: 10.15644/asc52/3/5

Objective: This study aimed to compare the difference in marginal dye penetration between everStick, Parapost XP, Parapost fiber white and control groups under gradual loading.
Materials and Methods: Sixty-eight human maxillary permanent incisors were divided into four groups. Each specimen was endodontically treated with step-back technique and prepared for each post system according to experimental groups, subsequently cemented in the canal. Composite resin cores were built and laboratory fabricated metal crowns were cemented. All specimens except those in the control group were subjected to thermal cycling. All groups were subjected to gradual loading from 0N-50N for 100 cycles. Specimens were sectioned transversely and the depths of dye penetration along the post were measured. Data were entered in SPSS ver. 22 and analyzed using two-way ANOVA test.
Results: There was no significant difference in marginal dye penetration between each group (p-value>0.05). However, there was a significant difference in percentage of marginal dye penetration between all groups (p-value<0.05); post-hoc comparison showed significant difference between Fiber White and Control groups (p-value=0.009).
Conclusion: All the groups showed dye penetration but the percentage was significant only between Parapost Fiber White and the control groups.

Matched MeSH terms: Metals
Effects of metal-contaminated soils on the accumulation of heavy metals in different parts of Centella asiatica: a laboratory study

Yap C, Mohd Fitri MR, Mazyhar Y, Tan S

Sains Malaysiana, 2010;39.

Centella asiatica is widely used as a medicinal plant in Malaysia and other parts of the world. In the present study, the growth and uptake of heavy metal by C. asiatica were determined based on the plant exposure to different treatment of metal-contaminated soils under laboratory conditions. Heavy metals uptake in different parts of the plants namely roots, stems and leaves were determined. In general, it was found that the metal uptake capacity followed the order: roots > stems > leaves. Since a close positive relationship was established between the concentrations of metal accumulated in different parts of the plant and the metal levels in the most contaminated soil, C. asiatica has the potential of being used as a biomonitoring plant for heavy metal pollution in the polluted soils.

Matched MeSH terms: Metals, Heavy
Effects of Ni, Fe and Mn exposures towards the growth of Anabaena floss-aquae in the batchculture

Khairiah Jusoh, Nik Marzuki Sidik, Mohd. Fahmi Ismail, Shaanaz Mohd. Yusof, Tunisah Risman, Ahmad Mahir Razali, et al.

Sains Malaysiana, 2008;37.

The aim of this work is to investigate the effect of exposure of heavy metals such as Ni, Fe and Mn on the growth of the cyanobacteria Anabaena flos-aquae, which can be found in fresh water environment. Results of the experiments showed that exposure of A. flos-aquae to Ni caused the most toxic effect as compared to exposure with Fe and Mn. The 96 hr LC50 value for Ni exposure was 0.321 mg/mL (approximately 30% inhibition), whereas Mn was the second most toxic metal followed by Fe with the 96 hr LC50 values of 0.684 mg/mL and 3.020 mg/mL respectively. This study demonstrated that even though Fe and Mn are essential micronutrients for A. flos-aquae, both show toxic effects at high concentrations. The difference in the toxicity value between Fe and Mn for A. flos-aquae is five times and this indicates that Mn was five times more toxic to A. flos-aquae than Fe suggesting that the Cyanobacteria is more tolerant to Fe when compared with Mn.

Matched MeSH terms: Metals, Heavy
Effects of vermicomposting duration to macronutrient elements and heavy metals concentrations in vermicompost

Adi Ainurzaman Jamaludin, Noor Zalina Mahmood

Sains Malaysiana, 2010;39.

Vermicomposting using Lumbricus rubellus was conducted in two different durations, 10 and 30 weeks in the same plots. Three different of treatments combination were prepared with eight replicates for each treatment namely cow dung : kitchen waste in 30:70 ratio (T1), cow dung : coffee grounds in 30:70 ratio (T2), and cow dung : kitchen waste : coffee grounds in 30:35:35 ratio (T3). Macronutrients elements in the vermicompost from each treatment were measured in the tenth and thirtieth week. Comparatively longer duration of vermicomposting by using Lumbricus rubellus enhanced the quality of vermicompost by the increase of the macronutrient elements while reducing the heavy metal concentration and C/N ratio.

Matched MeSH terms: Metals, Heavy
Synthesis and characterization of mixed ligand complexes of caffeine, adenine and thiocyanate with some transition metal ions

Shaker SA, Yang Farina, Mahmmod S, Eskender M

Sains Malaysiana, 2010;39.

An ethanolic solution of caffeine was added to an aqueous solution of metal salts and followed by adding ethanolic solution of adenine and an aqueous solution of potassium thiocyanate to give complexes with general formula [M(CA)2(Ad)X2] where CA is caffeine, Ad is adenine, X is thiocyanate ion and M is Co(II), Ni(II), Cu(II), Zn(II) and Cd(II). The resulting products were characterized using UV-visible and infrared spectroscopies. Elemental analyses were performed using C, H, N analysis and atomic absorption techniques. The magnetic susceptibility and the conductivity were also measured. The results suggested that the complexes have octahedral geometry.

Matched MeSH terms: Metals
Life cycle inventory of institutional medium-scaled co-composting of food waste and yard waste in tropical country

Chee Guan Ng, Sumiani Yusoff

Sains Malaysiana, 2015;44:517-527.

The main objective of the present study was to provide a comprehensive LCI of medium scale composting of food waste
and yard waste at institutional level, based on substance flow analysis (SFA). A secondary objective was to present the
composition and assess the quality of the final compost product from composting of typical Asian organic waste (food
waste and yard waste). The experiments were designed to represent a batch situation in an institutional medium size
composting scenario with input material of food waste mixed with grass clippings and dried leaves. Two composting
runs were carried out with the intention to showcase the heterogeneity of organic waste and study the effect of windrow
size on the performance of the process. The input and output material were sampled and characterized in order to
quantify the substance balance of the process. SFA was performed by means of the mass balance model STAN 2.5 to
compute unknown parameters (gaseous emissions). SFAs have been performed for C, N, K, P, Cd, Cr, Cu, Ni and Pb. The
composting windrows were fed with 212.4 and 393 kg, respectively. VS content reduction is greater in composting pile
with larger size (Run 2). The loss of C during composting was recorded in the range of 0.146-0.166 kg/kg ww. The C
losses via leachate were insignificant (0.02% of the total input C). The total N loss during the process was 0.005-0.012
kg/kg ww. The leachate generation was measured as 0.012-0.013 kg/kg ww. The flows of selected heavy metals were
assessed. Heavy metals were of minor significance due to low concentrations in the inputs (food waste and yard waste).
Heavy metals were found to be released to the atmosphere. However, majority of heavy metals remain in the finished
compost. The C/N reduction during the process was in the range of 10-23%. In general, the compost composition was
considered to be within the ranges previously reported in literature and thus ready for application in gardening. The LCI
presented in the present study can be used as a starting point for making environmental assessments of medium-scale
co-composting of food waste and yard waste in tropical environment. No major environmental problems were identified
from the process, except for the emissions of GHGs.

Matched MeSH terms: Metals, Heavy
A study on the potential of the periostracum of Perna Viridis as a biomonitoring material for Pb in tropical coastal waters based on correlation analysis

Yap C, Tan S

Sains Malaysiana, 2011;40:1179-1186.

The periostracum is the outermost layer overlying the inner prismatic and nacreous layers of the shells of bivalves. In the present study, the distributions of Cd and Pb in the soft tissues (ST) and periostracum of the green-lipped mussel Perna viridis sampled from 15 sampling sites in the coastal waters of Peninsular Malaysia were determined. The concentrations of Cd (0.21-10.87 mg/g dry weight) and Pb (1.16-40.20 mg/g dry weight) in the periostracum were generally higher than those in the ST (Cd: 0.10-5.55 mg/g dry weight; Pb: 2.53-18.62 mg/g dry weight). Based on correlation analysis from nine geographical populations, the higher correlation coefficients (R values) between the periostracum-geochemical fractions of the sediments than between the ST-geochemical fractions of the sediments indicated that the periostracum could be a potential biomonitoring material for Pb. Hence, the present results supported the use of the periostracum of P. viridis as a potential biomonitoring material for Pb but not for Cd. However, more studies are warranted to verify its usefulness for the biomonitoring of heavy metal pollution in tropical coastal waters.

Matched MeSH terms: Metals, Heavy
Kandungan logam berat terpilih dalam tanih ultrabes dan mengkudu (Morinda citrifolia) dari Kuala Pilah, Negeri Sembilan, Malaysia

Sahibin Abd. Rahim, Wan Mohd. Razi Idris, Zulfahmi Ali Rahman, Kadderi Md. Desa, Tukimat Lihan, Azman Hashim, et al.

Sains Malaysiana, 2009;38.

This study was carried out at an ultrabasic area, Selaru (S1 & S2) dan Felda Rokan Barat (S3), Kuala Pilah, Negeri Sembilan. Eighteen samples of plant and their substrates were collected from study area. The purpose of this study was to determine heavy metal such as Ni, Cr, Mn, Co, Fe and Zn contents in soils and different parts of the plant, such as leaf, stem, root and fruit. Biologal Absorption Coefficient (BAC) of the plant was obtained by calculation. Heavy metals content in the plant were extracted by digestion method whereas in soil the heavy metals were extracted by sequential extraction. Heavy metals content in soil and plant extract was determined using Flame Atomic Absorption Spectrophotometer. It was found that heavy metal concentrations in soil substrate for mengkudu (Morinda citrifolia) were high for Fe followed by Cr, Ni, Mn, Zn and Co with average concentration of 1208.5, 583.4, 352.4, 352.4, 70.7 and 53.6 mg.kg-1, respectively. Available Mn and Zn concentrations were higher than the other heavy metals in term of percentage. Fe and Mn were dominant in all parts of plants however in terms of BAC average, Co showed the highest enrichment value in all parts of the plants.

Matched MeSH terms: Metals, Heavy
A biomonitor of heavy metals on ruderal habitats in Turkey - Diplotaxis tenuifolia (L.) DC

Ozturk M, Sakcali S, Celik A

Sains Malaysiana, 2013;42:1371-1376.

Diplotaxis tenuifolia is a medicinally important perennial plant species, distributed widely alongside the roads in Turkey. The samples were collected from 54 sites, including highways, sideways, industrial areas, urban centres and rural environs. Both the plant and soil samples were analysed to determine the concentrations of different metals using AAS. The results showed that in the soil samples copper and lead were highest near highway 45.533 and 2.865 mg/kg, respectively; but lowest values of copper were determined around industrial areas (3.514 mg/kg), latter however showed higher concentrations of cadmium (0.726 mg/kg) and iron (82.766 mg/kg). The lead as well as iron were the lowest around sideways 1.917 mg/kg and 54.073 mg/kg, respectively, whereas chromium concentrations in the soils were highest near sideways (18.397 mg/kg) and lowest around industrial areas (0.182 mg/kg). The sideways showed very low nickel concentrations (0.271 mg/kg), as compared to the rural areas which had higher nickel concentrations (0.726 mg/kg). No cadmium was detected in the urban soil samples. In the plants copper and chromium were higher in the urban areas 50.130 and 0.238 mg/kg, respectively. The former was lowest around sideways (32.377 mg/kg) and latter around highways (0.114 mg/kg). Both nickel and cadmium were higher in the samples from industrial areas 0.238 and 0.016 mg/kg, respectively. Their values around the highways were lowest 0.182 and 0.005 mg/kg. The samples from urban sites revealed highest values of lead (3.474 mg/kg) and iron (61.304 mg/kg), but the values of lead were lowest around sideways (2.420 mg/kg) and those of iron in the vicinity of industrial areas (20.600 mg/kg). All these findings depict that there is some aerial deposition of these metals on the leaves. A significant correlation is seen between the plants and the soils.

Matched MeSH terms: Metals
A comparative study of condition indices and heavy metals in perna viridis populations at Sebatu and Muar, Peninsular Malaysia

Yap C, Al-Barwani S

Sains Malaysiana, 2012;41:1063-1069.

This study compared some allometric parameters (shell length, shell width, shell height, total dry weight of soft tissues, condition index and heavy metals (Cd, Cu, Pb and Zn) in the different soft tissues of Perna viridis collected from Sebatu and Muar estuary. It was found that the total dry weight of soft tissues and condition index of mussels collected from Sebatu were significantly (p<0.05) higher than those in Muar. The significantly (p<0.05) higher concentrations of Cu in most soft tissues and some of Cd indicated a higher bioavailability of Cu and Cd at Muar than Sebatu. In addition, the significantly (p<0.05) higher levels of Cu, Cd, Zn and Pb in surface sediments collected from Muar supported the observable anthropogenic impacts at Muar than Sebatu and hence, higher metal contamination at Muar than Sebatu. The higher condition index value in mussels recorded in Sebatu than in Muar was believed to be a result of higher metal contamination at Muar estuary.

Matched MeSH terms: Metals, Heavy
Sodium anilinide-cyclohexylamide pair: synthesis, characterization, and hydrogen storage properties

Jing Z, Yu Y, Chen R, Tan KC, He T, Wu A, et al.

Chem Commun (Camb), 2020 Jan 22.
PMID: 31967625 DOI: 10.1039/c9cc08593a

The lack of efficient hydrogen storage material is one of the bottlenecks for the large-scale implementation of hydrogen energy. Here, a series of new hydrogen storage materials, i.e., anilinide-cyclohexylamide pairs, are proposed via the metallation of an aniline-cyclohexylamine pair. DFT calculations show that the enthalpy change of hydrogen desorption (ΔHd) can be significantly tuned from 60.0 kJ per mol-H2 for the pristine aniline-cyclohexylamine pair to 42.2 kJ per mol-H2 for sodium anilinide-cyclohexylamide and 38.7 kJ per mol-H2 for potassium anilinide-cyclohexylamide, where an interesting correlation between the electronegativity of the metal and the ΔHd was observed. Experimentally, the sodium anilinide-cyclohexylamide pair was successfully synthesised with a theoretical hydrogen capacity of 4.9 wt%, and the hydrogenation and dehydrogenation cycle can be achieved at a relatively low temperature of 150 °C in the presence of commercial catalysts, in clear contrast to the pristine aniline-cyclohexylamine pair which undergoes dehydrogenation at elevated temperatures.

Matched MeSH terms: Metals
Fulltext Investigation of Micromachined Antenna Substrates Operating at 5 GHz for RF Energy Harvesting Applications

Mohd Yunus NH, Yunas J, Pawi A, Rhazali ZA, Sampe J

Micromachines (Basel), 2019 Feb 22;10(2).
PMID: 30813276 DOI: 10.3390/mi10020146

This paper investigates micromachined antenna performance operating at 5 GHz for radio frequency (RF) energy harvesting applications by comparing different substrate materials and fabrication modes. The research aims to discover appropriate antenna designs that can be integrated with the rectifier circuit and fabricated in a CMOS (Complementary Metal-Oxide Semiconductor)-compatible process approach. Therefore, the investigation involves the comparison of three different micromachined antenna substrate materials, including micromachined Si surface, micromachined Si bulk with air gaps, and micromachined glass-surface antenna, as well as conventional RT/Duroid-5880 (Rogers Corp., Chandler, AZ, USA)-based antenna as the reference. The characteristics of the antennas have been analysed using CST-MWS (CST MICROWAVE STUDIO®-High Frequency EM Simulation Tool). The results show that the Si-surface micromachined antenna does not meet the parameter requirement for RF antenna specification. However, by creating an air gap on the Si substrate using a micro-electromechanical system (MEMS) process, the antenna performance could be improved. On the other hand, the glass-based antenna presents a good S11 parameter, wide bandwidth, VSWR (Voltage Standing Wave Ratio) ≤ 2, omnidirectional radiation pattern and acceptable maximum gain of >5 dB. The measurement results on the fabricated glass-based antenna show good agreement with the simulation results. The study on the alternative antenna substrates and structures is especially useful for the development of integrated patch antennas for RF energy harvesting systems.

Matched MeSH terms: Metals
Case 263: Malaysian Charm Needles (Susuk)

Martin JL, Vlachou PA

Radiology, 2019 03;290(3):843-847.
PMID: 30789811 DOI: 10.1148/radiol.2019162113

History A 58-year-old woman was seen in the rheumatology clinic for bilateral wrist and knee pain that was unresponsive to physiotherapy and intra-articular steroid injections. Remote fracture of the left tibia from a motor vehicle collision was reported and was previously treated with conservative management. Serologic work-up for inflammatory disease was negative. The patient reported no prior surgical or medical history. Social history revealed remote immigration from Malaysia. Radiographs of the hands and knees were obtained.

Matched MeSH terms: Metals

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