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  1. Hassan B, Baig S, Aslam S
    Sensors (Basel), 2023 Aug 07;23(15).
    PMID: 37571774 DOI: 10.3390/s23156991
    Cell-free massive multiple-input multiple-output (MIMO) systems have the potential of providing joint services, including joint initial access, efficient clustering of access points (APs), and pilot allocation to user equipment (UEs) over large coverage areas with reduced interference. In cell-free massive MIMO, a large coverage area corresponds to the provision and maintenance of the scalable quality of service requirements for an infinitely large number of UEs. The research in cell-free massive MIMO is mostly focused on time division duplex mode due to the availability of channel reciprocity which aids in avoiding feedback overhead. However, the frequency division duplex (FDD) protocol still dominates the current wireless standards, and the provision of angle reciprocity aids in reducing this overhead. The challenge of providing a scalable cell-free massive MIMO system in an FDD setting is also prevalent, since computational complexity regarding signal processing tasks, such as channel estimation, precoding/combining, and power allocation, becomes prohibitively high with an increase in the number of UEs. In this work, we consider an FDD-based scalable cell-free network with angular reciprocity and a dynamic cooperation clustering approach. We have proposed scalability for our FDD cell-free and performed a comparative analysis with reference to channel estimation, power allocation, and precoding/combining techniques. We present expressions for scalable spectral efficiency, angle-based precoding/combining schemes and provide a comparison of overhead between conventional and scalable angle-based estimation as well as combining schemes. Simulations confirm that the proposed scalable cell-free network based on an FDD scheme outperforms the conventional matched filtering scheme based on scalable precoding/combining schemes. The angle-based LP-MMSE in the FDD cell-free network provides 14.3% improvement in spectral efficiency and 11.11% improvement in energy efficiency compared to the scalable MF scheme.
  2. Aslam S, Yee VC, Narayanan S, Duraisamy G, Standen GR
    Br J Haematol, 1997 Aug;98(2):346-52.
    PMID: 9266932
    Molecular analysis has been performed on a Malaysian patient with a severe bleeding disorder due to factor XIII(A) subunit deficiency. Total mRNA was isolated from the patient's leucocytes and four overlapping segments corresponding to the entire coding region of the A subunit cDNA were amplified by RT-PCR. The cDNA segments amplified efficiently and were of expected size. Direct sequencing of the complete reading frame revealed a single homozygous base change (nt 1327G-T) in exon 10 corresponding to a missense mutation, Val414Phe, in the catalytic core domain of the A subunit monomer. The mutation eliminates a BsaJ1 restriction site and family screening showed that both parents were heterozygous for the defect. The base substitution was absent in 55 normal individuals. Val414 is a highly conserved residue in the calcium-dependent transglutaminase enzyme family. Computer modelling based on 3D crystallographic data predicts that the bulky aromatic side chain of the substituted phenylalanine residue distorts protein folding and destabilizes the molecule. In addition, conformation changes in the adjacent catalytic and calcium binding regions of the A subunit are likely to impair the enzymatic activity of any protein synthesized.
  3. Abid N, Aslam S, Alghamdi AA, Kumar T
    Front Psychol, 2023;14:1020269.
    PMID: 36777200 DOI: 10.3389/fpsyg.2023.1020269
    INTRODUCTION: Reading is an attempt to comprehend the writer's message for personal growth and success in the relevant fields. Thus, psychologists consider it a multifaceted cognitive process of constructing meanings from texts. The present study was conducted to determine the relationships among students' reading habits, study skills, and academic achievement in English at the secondary level in Punjab, Pakistan.

    METHODS: The (n = 1614) students enrolled in the science section for the academic year 2019-2020 participated in this descriptive correlational survey, selected from 40 high schools in Lahore, Punjab, Pakistan, through a non-proportionate stratified random sampling technique. The Reading Habits Questionnaire (RHQ) and the Study Skills Scale (SSS) were used to collect data about students' reading habits and study skills. At the same time, academic achievement was the students' grades obtained in the ninth class in the subject of English that were determined by the Board of Intermediate and Secondary Education (BISE) Lahore in 2019. Students' responses were analyzed through descriptive and inferential statistics.

    RESULTS: The results indicated that students have competent reading habits and study skills. The correlational findings showed a strong positive relationship among reading habits, study skills, and academic achievement in English, while moderate positive relationships between reading habits and academic achievement in English. However, regression analysis results were significant, while reading habits and study skills moderately predicted academic achievement.

    DISCUSSION: It is implicated that teachers should plan such assignments and tasks based on reflective thinking by considering the role of study skills in academic achievement. Moreover, teachers and school administrators could mutually create timetables for library lessons to build reading habits and study skills among learners.

  4. Liu H, Khan AR, Aslam S, Rasheed AK, Mohsin M
    PMID: 34705201 DOI: 10.1007/s11356-021-16882-z
    This research examines how financial transformative power sector reforms affect energy efficiency and the economy in a sample of economies from South Asia, the Middle East, and Europe. We applied two stages of OLS, Bayesian VAR, and Data Envelopment Analysis (DEA) methods to a panel data set from 1995 to 2018. According to empirical findings, institutional deficiency has a negative effect on electricity reforms, implying that the greater the impact of reforms on electricity performance, the higher the institutional efficiency, A collection of reform initiatives involving a variety of reform agencies will boost energy efficiency by up to 13% and per capita electricity access by 62%. Despite recent reforms and regulatory measures, the electricity sector continues to face challenges in terms of private investment and structural flaws such as energy inefficiency, significant technological and financial losses, low power quality, and outdated transmission and network infrastructure. Interestingly 13.2% increases can be found in energy efficiency after electricity reforms. Unlike previous studies, our findings reveal a conflict between the broader economic effects and the welfare impact on electricity consumers.
  5. Phang P, Labadin J, Suhaila J, Aslam S, Hazmi H
    BMC Public Health, 2023 Jul 20;23(1):1396.
    PMID: 37474904 DOI: 10.1186/s12889-023-16300-8
    BACKGROUND: In Sarawak, 252 300 coronavirus disease 2019 (COVID-19) cases have been recorded with 1 619 fatalities in 2021, compared to only 1 117 cases in 2020. Since Sarawak is geographically separated from Peninsular Malaysia and half of its population resides in rural districts where medical resources are limited, the analysis of spatiotemporal heterogeneity of disease incidence rates and their relationship with socio-demographic factors are crucial in understanding the spread of the disease in Sarawak.

    METHODS: The spatial dependence of district-wise incidence rates is investigated using spatial autocorrelation analysis with two orders of contiguity weights for various pandemic waves. Nine determinants are chosen from 14 covariates of socio-demographic factors via elastic net regression and recursive partitioning. The relationships between incidence rates and socio-demographic factors are examined using ordinary least squares, spatial lag and spatial error models, and geographically weighted regression.

    RESULTS: In the first 8 months of 2021, COVID-19 severely affected Sarawak's central region, which was followed by the southern region in the next 2 months. In the third wave, based on second-order spatial weights, the incidence rate in a district is most strongly influenced by its neighboring districts' rate, although the variance of incidence rates is best explained by local regression coefficient estimates of socio-demographic factors in the first wave. It is discovered that the percentage of households with garbage collection facilities, population density and the proportion of male in the population are positively associated with the increase in COVID-19 incidence rates.

    CONCLUSION: This research provides useful insights for the State Government and public health authorities to critically incorporate socio-demographic characteristics of local communities into evidence-based decision-making for altering disease monitoring and response plans. Policymakers can make well-informed judgments and implement targeted interventions by having an in-depth understanding of the spatial patterns and relationships between COVID-19 incidence rates and socio-demographic characteristics. This will effectively help in mitigating the spread of the disease.

  6. Walayat K, Ahmad M, Rasul A, Aslam S, Anjum MN, Sultan S, et al.
    Pak J Pharm Sci, 2020 Mar;33(2(Supplementary)):855-860.
    PMID: 32863262
    The drug resistance phenomenon in microbes is resulting in the ineffectiveness of available drugs to treat the infections. Thus, there is a continued need to discover new molecules to combat the drug resistance phenomenon. Norfloxacin is a fluoroquinolone antibiotic that is used for the treatment of urinary tract infections. In this research work, norfloxacin is structurally modified by hybridizing with a range of substituted acetohydrazidic moieties through a multistep reaction. The first step involves the coupling of norfloxacin 1 with methyl chloroacetate followed by the treatment with hydrazine hydrate to result in corresponding acetohydrazide 3. A range of substituted benzaldehydes were reacted with the acetohydrazide to form the targeted series of norfloxacin derivatives 4a-i. The final compounds were screened for antimicrobial activity. Among the tested compounds, 4c, 4d, 4e and 4f displayed better antifungal activity against F.avenaceum, while compound 4c and 4e were active against F. bubigeum.
  7. Ibraheem F, Ahmad M, Ashfaq UA, Aslam S, Khan ZA, Sultan S
    Pak J Pharm Sci, 2020 Mar;33(2(Supplementary)):847-854.
    PMID: 32863261
    Pyrazoline and benzimidazoles derivatives have been widely studied due to their potential applications in the medicinal field. In this research project, we have hybridized these two heterocyclic systems in the same molecule. A new series of compounds, 2-((3,5-diaryl-4,5-dihydro-1H-pyrazol-1-yl)methyl)-1H-benzo[d]imidazole (5a-i) were synthesized through a multistep reaction. In the first step, chalcones 3a-i were prepared by coupling of various acetophenones and benzaldehydes under alkaline conditions. These chalcones were cyclized with hydrazine hydrate to form a series of pyrazolines which were finally coupled with 2-chloromethyl-1H-benzimidazole to get a new series of titled hybrid molecules. The structures of these compounds were elucidated by spectral (1H NMR and 13C NMR) analysis. The anti-diabetic potential of these compounds was studied by screening them for their α-glucosidase inhibition activity. The SAR was established through molecular docking analysis. Compound 5d appeared as effective inhibitor with IC50 = 50.06μM as compared to reference drug (acarbose) having IC50 = 58.8μM.
  8. Ahmad S, Zaib S, Jalil S, Shafiq M, Ahmad M, Sultan S, et al.
    Bioorg Chem, 2018 10;80:498-510.
    PMID: 29996111 DOI: 10.1016/j.bioorg.2018.04.012
    In this research work, we report the synthesis and biological evaluation of two new series of 1-benzyl-4-(benzylidenehydrazono)-3,4-dihydro-1H-benzo[c] [1,2]thiazine 2,2-dioxides and 1-benzyl-4-((1-phenylethylidene)hydrazono)-3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxides. The synthetic plan involves the mesylation of methyl anthranilate with subsequent N-benzylation of the product. The methyl 2-(N-benzylmethylsulfonamido)benzoate was subjected to cyclization reaction in the presence of sodium hydride to obtain 1-benzyl-1H-benzo[c][1,2]thiazin-4(3H)-one 2,2-dioxide which was treated with hydrazine hydrate to get corresponding hydrazone precursor. Finally, the titled compounds were obtained by reaction of hydrazone with various substituted aldehydes and ketones. The synthesized derivatives were subjected to carry out their inhibition activities against monoamine oxidases along with modelling investigations to evaluate their binding interactions and dynamic stability during the docking studies. The inhibition profile of potent compounds was found as competitive for both the isozymes. The compounds were more selective inhibitors of MAO-A as compared to MAO-B. Moreover, drug likeness profile of the derivatives was evaluated to have an additional insight into the physicochemical properties. The molecular dynamic simulations predicted the behaviour of amino acids with the active site residues.
  9. Saddique FA, Zaib S, Jalil S, Aslam S, Ahmad M, Sultan S, et al.
    Eur J Med Chem, 2018 Jan 01;143:1373-1386.
    PMID: 29126721 DOI: 10.1016/j.ejmech.2017.10.036
    Three series of 4-hydroxy-N'-[benzylidene/1-phenylethylidene]-2-H/methyl/benzyl-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides (9-11)a-l were synthesized and unraveled to be highly potent dual inhibitors of monoamine oxidases (MAO-A and MAO-B). All the examined compounds demonstrated IC50 values in lower micro-molar range for both MAO-A as well as MAO-B. The most active MAO-A inhibitor was 4-hydroxy-N'-(1-phenylethylidene)-2H-benzo[e][1,2]thiazine-3-carbohydrazide 1,1-dioxide (9i) with an IC50 value of 0.11 ± 0.005 μM, whereas, methyl 4-hydroxy-2H-benzo[e][1,2]thiazine-3-carboxylate 1,1-dioxide (3) was the most active MAO-B inhibitor with an IC50 value of 0.21 ± 0.01 μM. Enzyme kinetics studies revealed that the most potent compounds inhibited both MAO enzymes (A & B) in a competitive fashion. Molecular docking studies were also performed to obtain an intuitive picture of inhibition potential for potent inhibitors. The high potency of these compounds is optimally combined with highly favorable ADME profile with predicted good oral bioavailability.
  10. Abbas M, Aslam S, Abdullah FA, Riaz MB, Gepreel KA
    Heliyon, 2023 Sep;9(9):e19307.
    PMID: 37810099 DOI: 10.1016/j.heliyon.2023.e19307
    Spline curves are very prominent in the mathematics due to their simple construction, accuracy of assessment and ability to approximate complicated structures into interactive curved designs. A spline is a smooth piece-wise polynomial function. The primary goal of this study is to use extended cubic B-spline (ExCuBS) functions with a new second order derivative approximation to obtain the numerical solution of the weakly singular kernel (SK) non-linear fractional partial integro-differential equation (FPIDE). The spatial and temporal fractional derivatives are discretized by ExCuBS and the Caputo finite difference scheme, respectively. The present study found that it is stable and convergent. The validity of the current approach is examined on a few test problems, and the obtained outcomes are compared with those that have previously been reported in the literature.
  11. Rafiq A, Aslam S, Ahmad M, Nazir MS, Farooq A, Sultan S
    Mol Divers, 2023 Apr 24.
    PMID: 37095354 DOI: 10.1007/s11030-023-10647-1
    Heterocyclic compounds are attractive candidates because of their vast applications in natural and physical sciences. Thienothiophene (TT) is an annulated ring of two thiophene rings with a stable and electron-rich structure. Thienothiophenes (TTs) fully represent the planar system, which can drastically alter or improve the fundamental properties of organic, π-conjugated materials when included into a molecular architecture. These molecules possessed many applications including, pharmaceutical as well as optoelectronic properties. Different isomeric forms of thienothiophene showed various applications such as antiviral, antitumor, antiglaucoma, antimicrobial, and as semiconductors, solar cells, organic field effect transistors, electroluminiscents etc. A number of methodologies were adopted to synthesize thienothiophene derivatives. In this review, we have addressed different synthetic strategies of various isomeric forms of thienothiophene that have been reported during last seven years, i.e., 2016-2022.
  12. Dayrat B, Goulding TC, Apte D, Aslam S, Bourke A, Comendador J, et al.
    Zookeys, 2020;972:1-224.
    PMID: 33071542 DOI: 10.3897/zookeys.972.52853
    The genus Peronia Fleming, 1822 includes all the onchidiid slugs with dorsal gills. Its taxonomy is revised for the first time based on a large collection of fresh material from the entire Indo-West Pacific, from South Africa to Hawaii. Nine species are supported by mitochondrial (COI and 16S) and nuclear (ITS2 and 28S) sequences as well as comparative anatomy. All types available were examined and the nomenclatural status of each existing name in the genus is addressed. Of 31 Peronia species-group names available, 27 are regarded as invalid (twenty-one synonyms, sixteen of which are new, five nomina dubia, and one homonym), and four as valid: Peronia peronii (Cuvier, 1804), Peronia verruculata (Cuvier, 1830), Peronia platei (Hoffmann, 1928), and Peronia madagascariensis (Labbé, 1934a). Five new species names are created: P. griffithsi Dayrat & Goulding, sp. nov., P. okinawensis Dayrat & Goulding, sp. nov., P. setoensis Dayrat & Goulding, sp. nov., P. sydneyensis Dayrat & Goulding, sp. nov., and P. willani Dayrat & Goulding, sp. nov.Peronia species are cryptic externally but can be distinguished using internal characters, with the exception of P. platei and P. setoensis. The anatomy of most species is described in detail here for the first time. All the secondary literature is commented on and historical specimens from museum collections were also examined to better establish species distributions. The genus Peronia includes two species that are widespread across the Indo-West Pacific (P. verruculata and P. peronii) as well as endemic species: P. okinawensis and P. setoensis are endemic to Japan, and P. willani is endemic to Northern Territory, Australia. Many new geographical records are provided, as well as a key to the species using morphological traits.
  13. Saddique FA, Aslam S, Ahmad M, Ashfaq UA, Muddassar M, Sultan S, et al.
    Molecules, 2021 May 20;26(10).
    PMID: 34065194 DOI: 10.3390/molecules26103043
    Diabetes mellitus (DM) is a chronic disorder and has affected a large number of people worldwide. Insufficient insulin production causes an increase in blood glucose level that results in DM. To lower the blood glucose level, various drugs are employed that block the activity of the α-glucosidase enzyme, which is considered responsible for the breakdown of polysaccharides into monosaccharides leading to an increase in the intestinal blood glucose level. We have synthesized novel 2-(3-(benzoyl/4-bromobenzoyl)-4-hydroxy-1,1-dioxido-2H-benzo[e][1,2]thiazin-2-yl)-N-arylacetamides and have screened them for their in silico and in vitro α-glucosidase inhibition activity. The derivatives 11c, 12a, 12d, 12e, and 12g emerged as potent inhibitors of the α-glucosidase enzyme. These compounds exhibited good docking scores and excellent binding interactions with the selected residues (Asp203, Asp542, Asp327, His600, Arg526) during in silico screening. Similarly, these compounds also showed good in vitro α-glucosidase inhibitions with IC50 values of 30.65, 18.25, 20.76, 35.14, and 24.24 μM, respectively, which were better than the standard drug, acarbose (IC50 = 58.8 μM). Furthermore, a good agreement was observed between in silico and in vitro modes of study.
  14. Ahmad S, Jalil S, Zaib S, Aslam S, Ahmad M, Rasul A, et al.
    Eur J Pharm Sci, 2019 Apr 01;131:9-22.
    PMID: 30735822 DOI: 10.1016/j.ejps.2019.02.007
    We report the synthesis and biological evaluation of two new series of 2-amino-6-benzyl-4-phenyl-4,6-dihydrobenzo[c]pyrano[2,3-e][1,2]thiazine-3‑carbonitrile 5,5-dioxides and 2-amino-6-methyl-4-phenyl-4,6-dihydrobenzo[c]pyrano[2,3-e][1,2]thiazine-3‑carbonitrile 5,5-dioxides. The synthetic methodology involves a multistep reaction starting with methyl anthranilate which was coupled with methane sulfonyl chloride. The product of the reaction was subjected to N-benzylation and N-methylation reactions followed by ring closure with sodium hydride resulting in the formation of respective 2,1-benzothiazine 2,2-dioxides. These 2,1-benzothiazine precursors were subjected to multicomponent reaction with malononitrile and substituted benzaldehydes for the synthesis of two new series of pyranobenzothiazines (6a-r and 7a-r). The synthesized compounds were screened as selective inhibitors of monoamine oxidase A and monoamine oxidase B. The in vitro results suggested that compound 6d and 7q are the selective inhibitors of monoamine oxidase A, however, the selective and potent inhibitors of monoamine oxidase B included compounds 6h and 7r. Moreover, some dual inhibitors were noticed like 7l having more inhibitory activity towards both the isozymes. Moreover, the binding modes of the selective and potent inhibitors of monoamine oxidase A and B were investigated by molecular docking analysis. The results suggested that the synthetic derivatives may be potential towards the monoamine oxidase isozymes.
  15. Muñoz-Moreno R, Martínez-Romero C, Blanco-Melo D, Forst CV, Nachbagauer R, Benitez AA, et al.
    Cell Rep, 2019 12 17;29(12):3997-4009.e5.
    PMID: 31851929 DOI: 10.1016/j.celrep.2019.11.070
    Influenza A viruses (IAVs) have a remarkable tropism in their ability to circulate in both mammalian and avian species. The IAV NS1 protein is a multifunctional virulence factor that inhibits the type I interferon host response through a myriad of mechanisms. How NS1 has evolved to enable this remarkable property across species and its specific impact in the overall replication, pathogenicity, and host preference remain unknown. Here we analyze the NS1 evolutionary landscape and host tropism using a barcoded library of recombinant IAVs. Results show a surprisingly great variety of NS1 phenotypes according to their ability to replicate in different hosts. The IAV NS1 genes appear to have taken diverse and random evolutionary pathways within their multiple phylogenetic lineages. In summary, the high evolutionary plasticity of this viral protein underscores the ability of IAVs to adapt to multiple hosts and aids in our understanding of its global prevalence.
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