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A molecular dynamics study of Beta-Glucosidase B upon small substrate binding

Mazlan NS, Ahmad Khairudin NB

J Biomol Struct Dyn, 2016 Jul;34(7):1486-94.
PMID: 26261863 DOI: 10.1080/07391102.2015.1081570

Paenibacillus polymyxa β-glucosidase B (BglB), belongs to a GH family 1, is a monomeric enzyme that acts as an exo-β-glucosidase hydrolysing cellobiose and cellodextrins of higher degree of polymerization using retaining mechanism. A molecular dynamics (MD) simulation was performed at 300 K under periodic boundary condition for 5 ns using the complexes structure obtained from previous docking study, namely BglB-Beta-d-glucose and BglB-Cellobiose. From the root-mean-square deviation analysis, both enzyme complexes were reported to deviate from the initial structure in the early part of the simulation but it was stable afterwards. The root-mean-square fluctuation analysis revealed that the most flexible regions comprised of the residues from 26 to 29, 43 to 53, 272 to 276, 306 to 325 and 364 to 367. The radius of gyration analysis had shown the structure of BglB without substrate became more compact towards the end of the simulation compare to other two complexes. The residues His122 and Trp410 were observed to form stable hydrogen bond with occupancy higher than 10%. In conclusion, the behaviour of BglB enzyme towards the substrate binding was successfully explored via MD simulation approaches.
Fulltext A case of choroidal melanocytoma mimicking a choroidal melanoma

Ahmad SS, Lad L, Ghani SA

Saudi J Ophthalmol, 2015 Jul-Sep;29(3):242-5.
PMID: 26155089 DOI: 10.1016/j.sjopt.2015.02.002

A 17-year-old young girl was seen by us with complaints of progressive, painless decreasing vision in one eye for the last 4 years. No other supporting history could be elucidated. On examination, a large choroidal mass was found. Since the features were suggestive of malignant melanoma of the choroid, an enucleation of the eye was performed. Subsequently, histopathological examination of the enucleated eye revealed findings consistent with melanocytoma of the choroid. This case is unique in that the patient was of relatively young age and the tumor was huge compared to previous such reports.
Fulltext Maternal filicide among women admitted to forensic psychiatric institutions in Malaysia: case series

Razali S, Salleh RM, Yahya B, Ahmad SH

East Asian Arch Psychiatry, 2015 Jun;25(2):79-87.
PMID: 26118747

Objectives: To examine the characteristics of maternal filicide and describe the adverse life events experienced by women who have committed filicide and been hospitalised in forensic psychiatric institutions in Malaysia.
Methods: Registration records from 2000 through 2012 of female patients from 2 main forensic psychiatric institutions in Malaysia were reviewed. The medical records of patients who had committed maternal filicide were selected and descriptively evaluated.
Results: A total of 18 cases of maternal filicide were identified. Family dysfunction that presented with marital discord, domestic violence, or husband with substance abuse was the main stress experienced by the women. Three social circumstances, including an adolescent who became a victim of date rape; immigrants who experienced sexual abuse; and filicide-suicide precipitated by financial difficulties were highlighted.
Conclusion: Women who committed filicide had experienced various difficulties in their life. The presence of such life events might alert mental health professionals to investigate the possibility of filicide among their patients.
Key words: Depressive disorder; Domestic violence; Infanticide; Maternal behavior
Magnetophoresis of superparamagnetic nanoparticles at low field gradient: hydrodynamic effect

Leong SS, Ahmad Z, Lim J

Soft Matter, 2015 Sep 21;11(35):6968-80.
PMID: 26234726 DOI: 10.1039/c5sm01422k

Convective current driven by momentum transfer between magnetic nanoparticles (MNPs) and their surrounding fluid during magnetophoresis process under a low gradient magnetic field (<100 T m(-1)) is presented. This magnetophoresis induced convective flow, which imposed direct hydrodynamic effects onto the separation kinetics of the MNPs under low gradient magnetic separation (LGMS), is analogous to the natural convection found in heat transportation. Herein, we show the significance of the induced convection in controlling the transport behavior of MNPs, even at a very low particle concentration of 5 mg L(-1), and this feature can be characterized by the newly defined magnetic Grashof number. By incorporating fluid flow equations into the existing magnetophoresis model, we reveal two unique features of this convective flow associated with low gradient magnetophoresis, namely, (1) the continuous homogenization of the MNPs solution and (2) accompanying sweeping flow that accelerates the collection of MNPs. According to both simulation and experimental data, the induced convection boosts the magnetophoretic capture of MNPs by approximately 30 times compared to the situation with no convection.
Fulltext Metal phthalocyanine: fullerene composite nanotubes via templating method for enhanced properties

Ahmad Makinudin AH, Fakir MS, Supangat A

Nanoscale Res Lett, 2015;10:53.
PMID: 25852350 DOI: 10.1186/s11671-015-0741-6

The use of templating method to synthesize the vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) composite nanotubes is presented here. VOPcPhO is a p-type material and PC71BM is an n-type material which acts as an electron donor and electron acceptor, respectively. Both materials have been studied due to their potential applications as solar energy converter and organic electronics. High-resolution transmission electron microscope (HRTEM) and field emission scanning electron microscope (FESEM) images have shown the replication of the porous template diameter of approximately 200 nm with a superior incorporation of both VOPcPhO and PC71BM. VOPcPhO:PC71BM composite nanotubes showed the significant properties improvement if compared over their bulk heterojunction counterpart. UV-vis spectra of composite nanotubes show a shift to a longer wavelength at the absorption peaks. Significant quenching has been attained by the photoluminescence spectra of VOPcPhO:PC71BM composite nanotubes which supports the redshift of UV-vis absorption spectra. Presumably, the photo-induced charge transfer and charge carrier dissociation can be enhanced from the VOPcPhO:PC71BM composite nanotubes rather than the bulk heterojunction.
Fulltext Seed/catalyst-free growth of zinc oxide on graphene by thermal evaporation: effects of substrate inclination angles and graphene thicknesses

Ahmad NF, Yasui K, Hashim AM

Nanoscale Res Lett, 2015;10:10.
PMID: 25852308 DOI: 10.1186/s11671-014-0716-z

A seed/catalyst-free growth of ZnO on graphene by thermal evaporation of Zn in the presence of O2 gas was further studied. The effects of substrate positions and graphene thicknesses on the morphological, structural, and optical properties were found to be very pronounced. By setting the substrate to be inclined at 90°, the growth of ZnO nanostructures, namely, nanoclusters and nanorods, on single-layer (SL) graphene was successfully realized at temperatures of 600°C and 800°C, respectively. For the growth on multilayer (ML) graphene at 600°C with an inclination angle of 90°, the grown structures show extremely thick and continuous cluster structures as compared to the growth with substrate's inclination angle of 45°. Moreover, the base of nanorod structures grown at 800°C with an inclination angle of 90° also become thicker as compared to 45°, even though their densities and aspect ratios were almost unchanged. Photoluminescence (PL) spectra of the grown ZnO structures were composed of the UV emission (378-386 nm) and the visible emission (517-550 nm), and the intensity ratio of the former emission (I UV) to the latter emission (I VIS) changed, depending on the temperature. The structures grown at a low temperature of 600°C show the highest value of I UV/I VIS of 16.2, which is almost two times higher than the structures grown on SL graphene, indicating fewer structural defects. The possible growth mechanism was proposed and described which considered both the nucleation and oxidation processes. From the results obtained, it can be concluded that temperature below 800°C, substrate position inclined at 90° towards the gas flow, and ML graphene seems to be preferable parameters for the growth of ZnO structures by thermal evaporation because these factors can be used to overcome the problem of graphene's oxidation that takes place during the growth.
Fluorescence technique for the characterization of natural organic matter in river water

Ahmad UK, Ulang Z, Yusop Z, Fong TL

Water Sci Technol, 2002;46(9):117-25.
PMID: 12448460

The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase extraction (SPE) using C18 extraction cartridges were used to fractionate the water samples into humic and non-humic fractions. To differentiate and classify various types of humic substances, fluorescence was applied in emission, excitation and in synchronous-scan modes. A synchronous spectral profile was found to be able to differentiate humic and fulvic acids better than the emission or excitation spectra. Synchronous excitation spectra showed different spectral patterns for the water samples due to different origin. All water samples showed the presence of both fulvic and humic acids.
The use of an aberrant flexor carpi ulnaris tendon with an ulnar artery island forearm flap for reconstruction of a dorsal defect of the hand

Jeyaratnam TS, Ahmad TS, Kassim NM

Hand Surg, 2001 Jul;6(1):99-102.
PMID: 11677671
Curcumin in a model skin lotion formulation

Suhaimi H, Ahmad FB, Friberg SE

J Pharm Sci, 1995 Mar;84(3):376-80.
PMID: 7616381

A lamellar liquid crystalline region was identified in a typical skin lotion formulation system composed of a mixture of isostearic acid and triethanolamine (TEA) at 65:35 (w/w), decane, and water (the temperature was controlled at 30 degrees C). The interlayer spacings were determined by a small-angle X-ray diffraction technique. Incorporation of a natural dye, curcumin, resulted in lower interlayer spacings and higher penetration of water into the layered structure. However, the higher penetration of water was not apparent at all compositions of isostearic acid:TEA, decane, and water.
Fulltext Side effects of short course tuberculosis chemotherapy

Simon GK, Lye MS, Ahmad N

Med J Malaysia, 1991 Mar;46(1):88-94.
PMID: 1836044

A retrospective study of 300 tuberculosis patients on short course chemotherapy registered in 1985 at the Chest Clinic, General Hospital Alor Setar, Kedah was carried out with the purpose of identifying patient characteristics, determining incidence of side-effects and modifying treatment regimens in order to minimise these side-effects. One hundred and sixteen (38.7%) patients developed side effects. Twenty seven (9%) had side effects severe enough to warrant a change in treatment regimen. Treatment modifications and ways to minimise or control side effects are discussed.
Study site: Chest clinic, Hospital Alor Setar, Kedah, Malaysia
Fulltext Amoebiasis with multiple colonic perforations and ruptured liver abscess - a case report

Manukaran MN, Ahmad H, Abdullah I

Med J Malaysia, 1983 Mar;38(1):71-3.
PMID: 6633343

A case of amoebiasis with colonic perforation and ruptured liver abscess is reported. It is rare for both these complications to occur in the same patient. The management is described and the literature reviewed
Fulltext Evaluation with acoustic rhinometry of patients undergoing sinonasal surgery

Raja Ahmad RLA, Gendeh BS

Med J Malaysia, 2003 Dec;58(5):723-8.
PMID: 15190659

The purpose of this study is to evaluate the use of acoustic rhinometry in assessing surgical outcomes in sinonasal surgery. This prospective study was carried out from January till December 2001. A group of 44 patients who presented with nasal obstruction due to various rhinologic abnormality were examined with acoustic rhinometry pre and post-operatively. They were examined with acoustic rhinometry pre and post decongestion with cocaine and adrenaline. A highly significant correlation existed between minimal cross sectional area (MCA) and the subjective feeling of nasal problem, pre and post surgery. Thus MCA is a valuable parameter to express objectively the nasal patency. The mucovascular component of the nasal cavity plays a major role in the nasal patency as determined in the pre and post-decongestion acoustic rhinometry measurement. Acoustic rhinometry is a good tool to evaluate the nasal patency in cases where sinonasal surgery is considered in correcting the abnormality as well as for the post-operative evaluation.
Epidemiology of tuberculosis and leprosy, Sabah, Malaysia

Dony JF, Ahmad J, Yap KT

Tuberculosis (Edinb), 2004;84(1-2):8-18.
PMID: 14670341 DOI: 10.1016/j.tube.2003.08.002

The objectives in this epidemiology review are to measure and report the extent of morbidity and mortality due to tuberculosis (TB), the proportion of new sputum smear positive cases in districts and the status of cohort analysis as of 1999. As for leprosy, the main objective is to determine morbidity and the treatment outcomes of Multiple Drug Therapy (MDT). Based on the results obtained, a comprehensive action plan for prevention, control and monitoring of tuberculosis and leprosy cases and patients is being produced and implemented throughout the state. The analysis concentrated on patients diagnosed at all out-patient units and admitted in all of the state's hospitals. The patient particulars were recorded using a standardized format based on TB and Leprosy Health Management Information System (TB HMIS). TB was the second highest by notification of communicable diseases in Malaysia in 2001. 29% or about one-third of the national TB cases are from Sabah. However, it has been noted that there was an average decline of 2.6% in annual notification since 10 years ago to date. There was also a reduction of 11.4% in 2001 as compared to annual notification in 2000. Immigrants contribute more than 24% in detection of new cases since 1990. Treatment success rate in term of completion of treatment to date is 82%. Mortality rate has steadily declined from 14 deaths to 7 deaths per 100,000 population. Leprosy in Sabah also contributes to 30% of the yearly total caseload of Malaysia and has the highest notification rate of 2 per every 100,000 population as compared to other states. The average registered leprosy cases over the past 5 years are 239 cases and the prevalence rate is 0.7/10,000 population. The state has successfully achieved its goal to decrease leprosy as per the World Health Organization (WHO) goal of yearly overall prevalence rate of less than 1 case for every 10,000 population. However, the districts of Kudat, Tawau, Lahad Datu, Kota Kinabalu and Semporna are still within the prevalence rate of more than one per 10,000 population. This review highlights some interesting findings which can be incorporated into the State and Districts action plans and strategies. It is also noted that in order to translate National Plans and Strategies into effective action at the community level, health workers need relevant up-to-date knowledge of the pattern of health and disease, and of their determinants, in each district. The Sabah Health Department continues to organize and support programs related to management and control of tuberculosis and leprosy to progressively reduce the incidence of these diseases in the community by breaking the chain of transmission of Mycobacterium tuberculosis and M. leprae, respectively.
Study site: outpatient clinics, inpatients, hospitals, Sabah, Malaysia
Fulltext Medical professionalism videos on YouTube: Content exploration and appraisal of user engagement

Ahmad T, Sattar K, Akram A

Saudi J Biol Sci, 2020 Sep;27(9):2287-2292.
PMID: 32884409 DOI: 10.1016/j.sjbs.2020.06.007

Background: Social media has become the fastest growing platform for sharing and retrieving information and knowledge, and YouTube is one of the most popular and growing sources of health and educational information video-sharing website. But, videos on this open platform are not peer-assessed, therefore, the accessible data should be adequately assessed. Till date, no exploration and analysis for assessing the credibility and usefulness of Medical professionalism videos available on YouTube are conducted.
Objective: To analyze the video sources, contents and quality of YouTube videos about the topic of medical professionalism.
Methods: A systematic search was accomplished on YouTube videos during the period between March 1, 2020 and March 27, 2020. The phrases as significant words used throughout YouTube web search were 'Professionalism in Medical Education', Professionalism in medicine', 'Professionalism of medical students', 'Professionalism in healthcare'. 'Teaching professionalism', 'Attributes of professionalism'. The basic information collected for each video included author's/publisher's name, total number of watchers, likes, dislikes and positive and undesirable remarks. The videos were categorized into educationally useful and useless established on the content, correctness of the knowledge and the advices. Different variables were measured and correlated for the data analysis.YouTube website was searched the using keywords 'Professionalism in Medical Education', Professionalism in medicine', 'Professionalism of medical students', 'Professionalism in healthcare'. 'Teaching professionalism', and 'Attributes of professionalism'.
Results: After 2 rounds of screening by the subject experts and critical analysis of all the 137 YouTube videos, only 41 (29.92%) were identified as pertinent to the subject matter, i.e., educational type. After on expert viewing these 41 videos established upon our pre-set inclusion/exclusion criteria, only 17 (41.46%) videos were found to be academically valuable in nature.
Conclusion: Medical professionalism multimedia videos uploaded by the healthcare specialists or organizations on YouTube provided reliable information for medical students, healthcare workers and other professional. We conclude that YouTube is a leading and free online source of videos meant for students or other healthcare workers yet the viewers need to be aware of the source prior to using it for training learning.
Fulltext Ser-653-Asn substitution in the acetohydroxyacid synthase gene confers resistance in weedy rice to imidazolinone herbicides in Malaysia

Ruzmi R, Ahmad-Hamdani MS, Mazlan N

PLoS One, 2020;15(9):e0227397.
PMID: 32925921 DOI: 10.1371/journal.pone.0227397

The continuous and sole dependence on imidazolinone (IMI) herbicides for weedy rice control has led to the evolution of herbicide resistance in weedy rice populations across various countries growing IMI herbicide-resistant rice (IMI-rice), including Malaysia. A comprehensive study was conducted to elucidate occurrence, level, and mechanisms endowing resistance to IMI herbicides in putative resistant (R) weedy rice populations collected from three local Malaysian IMI-rice fields. Seed bioassay and whole-plant dose-response experiments were conducted using commercial IMI herbicides. Based on the resistance index (RI) quantification in both experiments, the cross-resistance pattern of R and susceptible (S) weedy rice populations and control rice varieties (IMI-rice variety MR220CL2 and non-IMI-rice variety MR219) to imazapic and imazapyr was determined. A molecular investigation was carried out by comparing the acetohydroxyacid synthase (AHAS) gene sequences of the R and S populations and the MR220CL2 and MR219 varieties. The AHAS gene sequences of R weedy rice were identical to those of MR220CL2, exhibiting a Ser-653-Asn substitution, which was absent in MR219 and S plants. In vitro assays were conducted using analytical grade IMI herbicides of imazapic (99.3%) and imazapyr (99.6%) at seven different concentrations. The results demonstrated that the AHAS enzyme extracted from the R populations and MR220CL2 was less sensitive to IMI herbicides than that from S and MR219, further supporting that IMI herbicide resistance was conferred by target-site mutation. In conclusion, IMI resistance in the selected populations of Malaysian weedy rice could be attributed to a Ser-653-Asn mutation that reduced the sensitivity of the target site to IMI herbicides. To our knowledge, this study is the first to show the resistance mechanism in weedy rice from Malaysian rice fields.
A new species of Cerapus (Amphipoda: Senticaudata: Ischyroceridae) from Pulau Bum Bum, Sabah, Malaysia, with an identification key to Cerapus species

Nurshazwan J, Ahmad-Zaki AB, Azman BAR

Zootaxa, 2020 Jun 24;4802(3):zootaxa.4802.3.7.
PMID: 33056047 DOI: 10.11646/zootaxa.4802.3.7

The first representative of the genus Cerapus in Malaysian waters, Cerapus bumbumiensis sp. nov. is described from specimens sampled from Pulau Bum Bum, Sabah (east Malaysia). The main identifying characteristics of this new amphipod species are: pereonites 1, 2 with constriction; male gnathopod 2 carpochelate, carpus large with long defining posterior tooth and well-developed anterodistal tooth; pereopod 6 coxa with fine hair/fringe setae ventrally; and telson with deep cleft. An updated identification key for the 23 known species in the genus is also presented.
Fulltext Factors associated with patient satisfaction towards pharmacy services among out-patients attending public health clinics: Questionnaire development and its application

Ismail A, Gan YN, Ahmad N

PLoS One, 2020;15(11):e0241082.
PMID: 33170854 DOI: 10.1371/journal.pone.0241082

INTRODUCTION: Patient satisfaction is widely used to measure quality of healthcare by identifying potential areas for improvement. Aim of study is to assess patient satisfaction towards pharmacy services and its associated factors using newly developed questionnaire among outpatients attending public health clinics.
MATERIALS AND METHODS: Public Health Clinic Patient Satisfaction Questionnaire (PHC-PSQ) towards pharmacy services was developed using exploratory factor analysis and Cronbach's α. A cross-sectional study was conducted among 400 patients visiting the pharmacy in three randomly selected public health clinics recruited via systematic random sampling. Data was collected using a set of questionnaire including PHC-PSQ. Factors associated with patient satisfaction was analysed using multiple linear regression.
RESULTS: Final PHC-PSQ consisted of three domains (administrative competency, technical competency and convenience of location) and 22 items with 69.9% total variance explained. Cronbach's α for total items was 0.96. Total mean score for patient satisfaction was 7.56 (SD 1.32). Older age and higher education were associated with lower patient satisfaction mean score. Patients who had visited the pharmacy more than once in the past three months, perceived to be in better health status and had a more correct general knowledge of pharmacists expressed higher patient satisfaction mean score.
CONCLUSIONS: PHC-PSQ is a newly developedtool to measure patient satisfaction towards pharmacy services in public health clinics in Malaysia. Patient satisfaction was relatively high. Age, education, frequency of visit, self-perceived health status and general knowledge of pharmacists were factors significantly associated with patient satisfaction.
Fulltext Development of Laser Drilling Strategy for Thick Carbon Fibre Reinforced Polymer Composites (CFRP)

Ahmad Sobri S, Heinemann R, Whitehead D

Polymers (Basel), 2020 Nov 12;12(11).
PMID: 33198377 DOI: 10.3390/polym12112674

Composites from carbon fibre reinforced polymers (CFRPs) play a significant role in modern manufacturing. They are typically used in aerospace and other industries that require high strength-to-weight ratios. Composite machining, however, remains a challenging job and sometimes is hampered by poor efficiency. Despite considerable research being conducted over the past few years on the machining of composite materials, the material nevertheless suffers from delamination, fibre loss, and imperfect finishing of the fuselage. Laser technology is becoming increasingly popular as an alternative approach to cutting and drilling composites. Experiments have been conducted with a CFRP thickness of 25.4 mm using fibre laser to test the effect of the machining parameters on the primary performance measurements. In this study, different machining criteria are used to assess the fibre laser ability of thick CFRP composites for drilling operation. The experimental findings revealed that a fibre laser is capable of penetrating a thick CFRP to a depth of 22 mm by using a novel drilling procedure.
Fulltext Correction: Ser-653-Asn substitution in the acetohydroxyacid synthase gene confers resistance in weedy rice to imidazolinone herbicides in Malaysia

Ruzmi R, Ahmad-Hamdani MS, Mazlan N

PLoS One, 2020;15(12):e0244686.
PMID: 33351858 DOI: 10.1371/journal.pone.0244686

[This corrects the article DOI: 10.1371/journal.pone.0227397.].
Fulltext Bioavailability of zinc oxide nano particle with fly ash soil for the remediation of metals by Parthenium hysterophorus

Ahmad A, Ghufran R, Al-Hosni TK

J Environ Health Sci Eng, 2019 Dec;17(2):1195-1203.
PMID: 32030185 DOI: 10.1007/s40201-019-00434-2

To investigate the interaction of zinc oxide nanoparticles (ZnO NPs) with fly ash soil (FAS) for the reduction of metals from FAS by Parthenium hysterophorus were studied. The average accumulation of metals by P. hysterophorus stem were Fe 79.6%; Zn 88.5%; Cu 67.5%; Pb 93.6%; Ni 43.5% and Hg 39.4% at 5.5 g ZnO NP. The concentration of ZnO NP at 1.5 g did not affect the metals accumulation, however at 5.5 g ZnO NP showed highest metal reduction was 96.7% and at 10.5-15.5 g ZnO NP of 19.8%. The metal reduction rate was R
max
for Fe 16.4; Zn 21.1; Pb 41.9; Hg 19.1 was higher than Ni 6.4 and Cu 11.3 from the FAS at 5.5 g ZnO NP whereas, the reduction rate of Pb showed highest. With doses of 5.5 g ZnO NP the biomass increased upto 78%; the metal reduced upto 98.7% with the share of 100% ZnO NP from FAS. Further investigation with phytotoxicity the plant reactive oxygen species (ROS) production were affected due was mainly due to the recovery of metals from FAS (R2 = 0.99).

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