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  1. Piezoresistive Effect in Plasma-Doping of Graphene Sheet for High-Performance Flexible Pressure Sensing Application
    Haniff MASM, Hafiz SM, Huang NM, Rahman SA, Wahid KAA, Syono MI, et al.
    ACS Appl Mater Interfaces, 2017 May 03;9(17):15192-15201.
    PMID: 28418234 DOI: 10.1021/acsami.7b02833
    This paper presents a straightforward plasma treatment modification of graphene with an enhanced piezoresistive effect for the realization of a high-performance pressure sensor. The changes in the graphene in terms of its morphology, structure, chemical composition, and electrical properties after the NH3/Ar plasma treatment were investigated in detail. Through a sufficient plasma treatment condition, our studies demonstrated that plasma-treated graphene sheet exhibits a significant increase in sensitivity by one order of magnitude compared to that of the unmodified graphene sheet. The plasma-doping introduced nitrogen (N) atoms inside the graphene structure and was found to play a significant role in enhancing the pressure sensing performance due to the tunneling behavior from the localized defects. The high sensitivity and good robustness demonstrated by the plasma-treated graphene sensor suggest a promising route for simple, low-cost, and ultrahigh resolution flexible sensors.
  2. Fulltext Development of Organo-Dispersible Graphene Oxide via Pseudo-Surface Modification for Thermally Conductive Green Polymer Composites
    Sim S, Andou Y, Bashid HAA, Lim H, Altarawneh M, Jiang Z, et al.
    ACS Omega, 2018 Dec 31;3(12):18124-18131.
    PMID: 31458398 DOI: 10.1021/acsomega.8b02478
    Graphene has attracted lots of researchers attention because of its remarkable conductivity in both electrically and thermally. However, it has poor dispersibility in organic solvents which limited its applications. Polymers with aromatic end group which act as an intercalator were prepared by ring-opening polymerization with ε-caprolactone by utilizing 1-naphthalene methanol (1-NM) as an initiator. These intercalators will exist between graphene oxide (GO) sheets to prevent aggregation via interactions. The attachment of 1-NM on polymer chains was supported by ultraviolet-visible spectra, size exclusion chromatography profiles, and 1H nuclear magnetic resonance spectra. Exfoliated structured functionalized GO (fGO)/polycaprolactone (PCL) (synthesized fGO) nanocomposites that dispersed well in acetone, chloroform, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, and toluene were successfully synthesized. This agreed well with the enlarged interlayer spacing in the optimized fGO as compared to that of GO from density functional theory simulations using the DMol3 module that implemented in the Materials Studio 6.0. Furthermore, its potential to be applied as green electronics in electronics, aerospace, and automotive industries was presented, by trailering the thermal conductivity enhancement from the incorporation of fGO/PCL with commercialized biodegradable polymers, PCL, and poly[(R)-3-hydroxybutyric acid].
  3. Unconfined compression properties of a porous poly(vinyl alcohol)-chitosan-based hydrogel after hydration
    Lee SY, Pereira BP, Yusof N, Selvaratnam L, Yu Z, Abbas AA, et al.
    Acta Biomater, 2009 Jul;5(6):1919-25.
    PMID: 19289306 DOI: 10.1016/j.actbio.2009.02.014
    A poly(vinyl alcohol) (PVA) hydrogel composite scaffold containing N,O-carboxymethylated chitosan (NOCC) was tested to assess its potential as a scaffold for cartilage tissue engineering in a weight-bearing environment. The mechanical properties under unconfined compression for different hydration periods were investigated. The effect of supplementing PVA with NOCC (20wt.% PVA:5vol.% NOCC) produced a porosity of 43.3% and this was compared against a non-porous PVA hydrogel (20g PVA: 100ml of water, control). Under non-hydrated conditions, the porous PVA-NOCC hydrogel behaved in a similar way to the control non-porous PVA hydrogel, with similar non-linear stress-strain response under unconfined compression (0-30% strain). After 7days' hydration, the porous hydrogel demonstrated a reduced stiffness (0.002kPa, at 25% strain), resulting in a more linear stiffness relationship over a range of 0-30% strain. Poisson's ratio for the hydrated non-porous and porous hydrogels ranged between 0.73 and 1.18, and 0.76 and 1.33, respectively, suggesting a greater fluid flow when loaded. The stress relaxation function for the porous hydrogel was affected by the hydration period (from 0 to 600s); however the percentage stress relaxation regained by about 95%, after 1200s for all hydration periods assessed. No significant differences were found between the different hydration periods between the porous hydrogels and control. The calculated aggregate modulus, H(A), for the porous hydrogel reduced drastically from 10.99kPa in its non-hydrated state to about 0.001kPa after 7days' hydration, with the calculated shear modulus reducing from 30.92 to 0.14kPa, respectively. The porous PVA-NOCC hydrogel conformed to a biphasic, viscoelastic model, which has the desired properties required for any scaffold in cartilage tissue engineering.
  4. Bis[N,N-bis(2-hydroxyethyl)dithiocarbamato]dimethyltin(IV)
    Ng SW, Yang Farina AA, Othman AH, Baba I, Sivakumar K, Fun HK
    Acta Crystallogr C, 2000 Mar 15;56(Pt 3):E84-5.
    PMID: 15263206
    The title compound, [Sn(CH(3))(2)(C(5)H(10)NO(2)S(2))(2)], has crystallographic mirror symmetry (C-Sn-C on mirror plane) and the coordination polyhedron around the Sn atom is a tetrahedron [C-Sn-C 139.3 (2) degrees and S-Sn-S 82.3 (1) degrees ] distorted towards a skew-trapezoidal bipyramid owing to an intramolecular Sn.S contact [3.0427 (6) A]. The molecules are linked into a linear chain by intermolecular O-H.O hydrogen bonds [O.O 2.646 (3) A].
  5. Fulltext 5-Chloro-5''-[4-(di-methyl-amino)-benzyl-idene]-4'-[4-(di-methyl-amino)-phen-yl]-1',1''-di-methyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione
    Farag IS, Girgis AS, Ramadan AA, Moustafa AM, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jan 01;70(Pt 1):o70-1.
    PMID: 24855471 DOI: 10.1107/S1600536813033771
    The title compound, C34H38ClN5O2, has spiro links connecting the pyrrolidine ring and indole residue, as well as the piperidine and pyrrolidine rings. A half-chair conformation is found for the piperidine ring with the C atom connected to the spiro-C atom lying 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å). The methyl-ene C atom is the flap in the envelope conformation for the pyrrolidine ring. In the crystal, supra-molecular chains are sustained by alternating eight-membered {⋯HNCO}2 and 14-membered {⋯HC5O}2 synthons. Chains are connected into a three-dimensional network by (pyrrolidine-bound phenyl-meth-yl)C-H⋯π(pyrrolidine-bound phen-yl) edge-to-face inter-actions.
  6. Fulltext 5-Chloro-5''-(4-chloro-benzyl-idene)-4'-(4-chloro-phen-yl)-1''-ethyl-1'-methyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione
    Farag IS, Girgis AS, Ramadan AA, Moustafa AM, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jan 01;70(Pt 1):o43-4.
    PMID: 24855468 DOI: 10.1107/S1600536813033096
    Two spiro links are found in the title compound, C31H28Cl3N3O2, one connecting the piperidine and pyrrolidine rings, and the other connecting the pyrrolidine ring and indole residue. The piperidine ring adopts a half-chair conformation, in which the C atom connected to the spiro-C atom lies 0.741 (3) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.053 Å). The pyrrolidine ring has an envelope conformation with the flap atom being the methyl-ene C atom. Centrosymmetric eight-membered {⋯HNCO}2 amide dimers are the most significant feature of the crystal packing. These are connected into layers parallel to (-120) by C-H⋯O and π-π inter-actions between pyrrolidine-bound benzene rings [inter-centroid distance = 3.8348 (15) Å]. Slipped face-to-face inter-actions between the edges of pyrrolidine-bound benzene [shortest C⋯C separation = 3.484 (4) Å] connect the layers into a three-dimensional architecture.
  7. Fulltext 5''-Benzyl-idene-5-chloro-1',1''-dimethyl-4'-phenyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione
    Farag IS, Girgis AS, Ramadan AA, Moustafa AM, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jan 01;70(Pt 1):o22-3.
    PMID: 24855467 DOI: 10.1107/S1600536813032765
    The title compound, C30H28ClN3O2, features two spiro links, one connecting the piperidine and pyrrolidine rings, and the other connecting the pyrrolidine ring and indole residue. The configuration about the ethene bond is E. The piperidine ring adopts a half-chair conformation where the C atom connected to the spiro-C atom lies 0.713 (3) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.086 Å). The pyrrolidine ring has an envelope conformation with the flap atom being the methyl-ene C atom. Centrosymmetric eight-membered {⋯HNCO}2 amide synthons feature in the crystal packing. These are consolidated into a three-dimensional architecture by phen-yl-pyrrolidine C-H⋯N and chloro-benzene-pyrrolidine-bound phenyl C-H⋯π inter-actions.
  8. Computed tomography of the brain in predicting outcome of traumatic intracranial haemorrhage in Malaysian patients
    Azian AA, Nurulazman AA, Shuaib L, Mahayidin M, Ariff AR, Naing NN, et al.
    Acta Neurochir (Wien), 2001;143(7):711-20.
    PMID: 11534693
    Head injury is a significant economic, social and medical problem all over the world. Road accidents are the most frequent cause of head injury in Malaysia with highest risk in the young (15 to 24 years old). The associated outcomes include good recovery, possibility of death for the severely injured, which may cause disruption of the lives of their family members. It is important to predict the outcome as it will provide sound information to assist clinicians in Malaysia in providing prognostic information to patients and their families, to assess the effectiveness of different modes of treatment in promoting recovery and to document the significance of head injury as a public health problem.

    RESULTS: A total of 103 cases with intracranial haemorrhage i.e. intracerebral haemorrhage, extradural haemorrhage, subdural haemorrhage, intraventricular haemorrhage, haemorrhagic contusion and subarachnoid haemorrhage, following motor vehicle accidents was undertaken to study factors contributing to either good or poor outcome according to the Glasgow Outcome Scale. Patients below 12 years of age were excluded. The end point of the study was taken at 24 months post injury. The selected variables were incorporated into models generated by logistic regression techniques of multivariate analysis to see the significant predictors of outcome as well as the correlation between the CT findings with GCS.

    CONCLUSION: Significant predictors of outcome were GCS on arrival in the accident emergency department, pupillary reflex and the CT scan findings. The CT predictors of outcome include ICH, EDH, IVH, present of SAH, site of ICH, volumes of EDH and SDH as well as midline shift.

  9. Association of p53 tumor suppressor gene with paraclinical and clinical modalities of gliomas patients in Malaysia
    Yusoff AA, Abdullah J, Abdullah MR, Mohd Ariff AR, Isa MN
    Acta Neurochir (Wien), 2004 Jun;146(6):595-601.
    PMID: 15168228
    Alteration of the tumor suppressor gene p53 is considered to be a critical step in the development of human cancer. Changes in this gene have been detected in a wide range of human tumours, including gliomas. In glioma, the presence of p53 gene alterations has been associated with worse prognosis.
  10. Small interfering RNA for cancer treatment: overcoming hurdles in delivery
    Charbe NB, Amnerkar ND, Ramesh B, Tambuwala MM, Bakshi HA, Aljabali AAA, et al.
    Acta Pharm Sin B, 2020 Nov;10(11):2075-2109.
    PMID: 33304780 DOI: 10.1016/j.apsb.2020.10.005
    In many ways, cancer cells are different from healthy cells. A lot of tactical nano-based drug delivery systems are based on the difference between cancer and healthy cells. Currently, nanotechnology-based delivery systems are the most promising tool to deliver DNA-based products to cancer cells. This review aims to highlight the latest development in the lipids and polymeric nanocarrier for siRNA delivery to the cancer cells. It also provides the necessary information about siRNA development and its mechanism of action. Overall, this review gives us a clear picture of lipid and polymer-based drug delivery systems, which in the future could form the base to translate the basic siRNA biology into siRNA-based cancer therapies.
  11. Response to: Depolarization vs. repolarization: what is the mechanism of ventricular arrhythmogenesis underlying sodium channel haploinsufficiency in mouse hearts?
    Jeevaratnam K, Guzadhur L, Goh YM, Grace AA, Huang CL
    Acta Physiol (Oxf), 2016 12;218(4):236-238.
    PMID: 27272698 DOI: 10.1111/apha.12731
  12. Sodium channel haploinsufficiency and structural change in ventricular arrhythmogenesis
    Jeevaratnam K, Guzadhur L, Goh YM, Grace AA, Huang CL
    Acta Physiol (Oxf), 2016 Feb;216(2):186-202.
    PMID: 26284956 DOI: 10.1111/apha.12577
    Normal cardiac excitation involves orderly conduction of electrical activation and recovery dependent upon surface membrane, voltage-gated, sodium (Na(+) ) channel α-subunits (Nav 1.5). We summarize experimental studies of physiological and clinical consequences of loss-of-function Na(+) channel mutations. Of these conditions, Brugada syndrome (BrS) and progressive cardiac conduction defect (PCCD) are associated with sudden, often fatal, ventricular tachycardia (VT) or fibrillation. Mouse Scn5a(+/-) hearts replicate important clinical phenotypes modelling these human conditions. The arrhythmic phenotype is associated not only with the primary biophysical change but also with additional, anatomical abnormalities, in turn dependent upon age and sex, each themselves exerting arrhythmic effects. Available evidence suggests a unified binary scheme for the development of arrhythmia in both BrS and PCCD. Previous biophysical studies suggested that Nav 1.5 deficiency produces a background electrophysiological defect compromising conduction, thereby producing an arrhythmic substrate unmasked by flecainide or ajmaline challenge. More recent reports further suggest a progressive decline in conduction velocity and increase in its dispersion particularly in ageing male Nav 1.5 haploinsufficient compared to WT hearts. This appears to involve a selective appearance of slow conduction at the expense of rapidly conducting pathways with changes in their frequency distributions. These changes were related to increased cardiac fibrosis. It is thus the combination of the structural and biophysical changes both accentuating arrhythmic substrate that may produce arrhythmic tendency. This binary scheme explains the combined requirement for separate, biophysical and structural changes, particularly occurring in ageing Nav 1.5 haploinsufficient males in producing clinical arrhythmia.
  13. Survey of chloroquine-resistant mutations in the Plasmodium falciparum pfcrt and pfmdr-1 genes in Hadhramout, Yemen
    Bamaga OA, Mahdy MA, Lim YA
    Acta Trop, 2015 Sep;149:59-63.
    PMID: 26001972 DOI: 10.1016/j.actatropica.2015.05.013
    Malaria is still a major public health problem in Yemen. More than 95% of the malaria cases are due to Plasmodium ‎falciparum‎. Recently in Yemen, the antimalarial treatment policy was changed from chloroquine (CQ) to artemisinin combination therapy (ACTs). However, CQ is still available and prescribed in the Yemeni market. The persistence of CQ resistance will be prolonged if the shift to ACT and the simultaneous withdrawal of CQ are not rigorously implemented. The aim of the current survey is to detect chloroquine-resistant mutations in P. falciparum chloroquine-resistance transporter (pfcrt) and P. falciparum multi-drug resistance-1 (pfmdr1) genes. These data will be important for future monitoring and assessment of antimalarial drug policy in Yemen. Blood specimens were collected from 735 individuals from different districts of the Hadhramout province, Yemen by house-to-house visit. Mutation-specific nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP) methods were used to investigate the mutations in the pfmdr1(codons 86 and 1246) and pfcrt (codons 76, 271, 326, 356 and 371) genes. The overall prevalence of pfcrt mutations at codons 76, 271, 326 and 371 were 50.4%, 58.7%, 54.3% and 44.9%, respectively. All isolates had wild-type pfcrt 356 allele. The majority of pfmdr1 86 alleles (83.3%) and all pfmdr1 1246 alleles were wild type. There was no association between pfcrt mutations and symptomatology, gender and age groups. In conclusion, point mutations in codons 76, 271, 326 and 371 of pfcrt of P. falciparum are high suggesting a sustained high CQ resistance even after 4 years of shifting to ACTs. These findings warrant complete withdrawal of CQ use from the Yemeni market for P. falciparum and careful usage of CQ for treating Plasmodium vivax.
  14. Development of animal disease data bank in Malaysia
    Jamaluddin AA, Chang KW, Johar MS, Yaacob H
    Acta Vet Scand Suppl, 1988;84:194-6.
    PMID: 3232606
  15. [Possibilities for predicting of cardiac arrhythmias and conductivity disorders in former athletes.]
    Krysiuk OB, Obrezan AG, Zadvorev SF, Yakovlev AA
    Adv Gerontol, 2020;33(1):131-136.
    PMID: 32362096
    In order to analyze the relationship between the athletic qualification and syndrome of cardiac rhythm and conductivity disturbances in former athletes, a retrospective analysis of medical records of 39 male former athletes with cardiovascular complaints (mean age 61,6±11,3 years, mean duration of career in sports 23,9±17,3 years, mean duration of post-athletic period 20,1±9,9 years) was carried out. The patients were screened for cardiac arrhythmias and underwent echocardiography. The overall prevalence of sustained paroxysms of atrial fibrillation was 42%, increasing with the athletic qualification. Ryan grade 4b-5 premature ventricular contractions were found in 14% of patients. 3 parameters were found to be the independent predictors of arrhythmias in former athletes, i. e. athletic qualification, multifocal atherosclerosis (as an anti-risk factor), and age. The coefficient of determinance for the created prognostic model reached 43%. Further prospective studies are needed to validate an algorithm.
  16. Rhinitis associated with asthma is distinct from rhinitis alone: The ARIA-MeDALL hypothesis
    Bousquet J, Melén E, Haahtela T, Koppelman GH, Togias A, Valenta R, et al.
    Allergy, 2023 Feb 17.
    PMID: 36799120 DOI: 10.1111/all.15679
    Asthma, rhinitis, and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of "one-airway-one-disease," coined over 20 years ago, is a simplistic approach of the links between upper- and lower-airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitization and multimorbidity, (iii) advances in mHealth for novel phenotype definitions, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches, and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper- and lower-airway allergic diseases with skin, gut, and neuropsychiatric multimorbidities, is the "Epithelial Barrier Hypothesis." This review determined that the "one-airway-one-disease" concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme "allergic" (asthma) phenotype combining asthma, rhinitis, and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll-Like Receptors and IL-17 for rhinitis alone as a local disease; IL-33 and IL-5 for allergic and non-allergic multimorbidity as a systemic disease), (ii) allergen sensitization patterns (mono- or pauci-sensitization versus polysensitization), (iii) severity of symptoms, and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and autoimmune diseases.
  17. THE PERSISTENCE OF FOCI OF LEPTOTROMBIDIUM (LEPTOTROMBIDIUM) AKAMUSHI ALONG A TRANSECT IN MALAYA (ACARINA: TROMBICULIDAE)
    HUBERT AA, BAKER HJ
    Am J Hyg, 1963 Sep;78:143-9.
    PMID: 14063718
  18. STUDIES ON THE HABITATS AND POPLUATION OF LEPTOTROMBIDIUM (LEPTOTROMBIDIUM) AKAMUSHI AND L. (L.) DELIENSIS IN MALAYA (ACARINA: TROMBICULIDAE)
    HUBERT AA, BAKER HJ
    Am J Hyg, 1963 Sep;78:131-42.
    PMID: 14063717
  19. Plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest,Sarawak, Malaysia
    Sakai S, Momose K, Yumoto T, Nagamitsu T, Nagamasu H, Hamid AA, et al.
    Am J Bot, 1999 Oct;86(10):1414-36.
    PMID: 10523283
    The first systematic observation of a general flowering, a phenomenon unique to lowland mixed-dipterocarp forests in Southeast Asia, is presented. During general flowering, which occurs at irregular intervals of 3-10 yr, nearly all dipterocarp species together with species of other families come heavily into flower. We monitored reproductive phenology of 576 individual plants representing 305 species in 56 families in Sarawak, Malaysia. Observations continued for 53 mo from August 1992 and covered one episode of a general flowering cycle. Among 527 effective reproductive events during 43 mo, 57% were concentrated in the general flowering period (GFP) of 10 mo in 1996. We classified 257 species into flowering types based on timing and frequency of flowering. The most abundant type was "general flowering" (35%), which flowered only during GFP. The others were "supra-annual" (19%), "annual" (13%), and "sub-annual" (5%) types. General flowering type and temporal aggregation in reproductive events were commonly found among species in various categories of taxonomic groups, life forms, pollination systems, and fruit types. Possible causes for general flowering, such as promotion of pollination brought about by interspecific synchronization and paucity of climatic cues suitable for flowering trigger, are proposed, in addition to the predator satiation hypothesis of Janzen (1974).
  20. MRI for the diagnosis of cardiac and liver iron overload in patients with transfusion-dependent thalassemia: An algorithm to guide clinical use when availability is limited
    Viprakasit V, Ajlan A, Aydinok Y, Al Ebadi BAA, Dewedar H, Ibrahim AS, et al.
    Am J Hematol, 2018 06;93(6):E135-E137.
    PMID: 29473204 DOI: 10.1002/ajh.25075
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