Displaying all 18 publications

Abstract:
Sort:
  1. Almasi D, Sadeghi M, Lau WJ, Roozbahani F, Iqbal N
    Mater Sci Eng C Mater Biol Appl, 2016 Jul 01;64:102-107.
    PMID: 27127033 DOI: 10.1016/j.msec.2016.03.053
    The present work reviews the current fabrication methods of the functionally graded polymeric material (FGPM) and introduces a novel fabrication method that is versatile in applications as compared to those of existing used methods. For the first time electrophoresis was used to control the distribution of the tetracycline hydrochloride (TC) in a film made of polylactic acid (PLA), aiming to induce antimicrobial effect on the film prepared. The elemental analysis on the film surface showed that by employing electrophoresis force, higher amount of TC was detected near the top surface of the film. Results also showed that the FGPM samples with higher percentage of the TC on the film surface were highly effective to minimize the growth of Escherichia coli. These findings are useful and important to improve dispersion quality of the particles in the composite material and further enhance its antibacterial property.
  2. Almasi D, Izman S, Sadeghi M, Iqbal N, Roozbahani F, Krishnamurithy G, et al.
    Int J Biomater, 2015;2015:475435.
    PMID: 25838826 DOI: 10.1155/2015/475435
    Polyether ether ketone (PEEK) is considered the best alternative material for titanium for spinal fusion cage implants due to its low elasticity modulus and radiolucent property. The main problem of PEEK is its bioinert properties. Coating with hydroxyapatite (HA) showed very good improvement in bioactivity of the PEEK implants. However the existing methods for deposition of HA have some disadvantages and damage the PEEK substrate. In our previous study a new method for deposition of HA on PEEK was presented. In this study cell proliferation of mesenchymal stem cell and apatite formation in simulated body fluid (SBF) tests were conducted to probe the effect of this new method in improvement of the bioactivity of PEEK. The mesenchymal stem cell proliferation result showed better cells proliferation on the treated layer in comparison with untreated PEEK. The apatite formation results showed the growth of the HA on the treated PEEK but there was not any sight of the growth of HA on the untreated PEEK even after 2 weeks. The results showed the new method of the HA deposition improved the bioactivity of the treated PEEK in comparison with the bare PEEK.
  3. Yu M, Kubiczek J, Ding K, Jahanzeb A, Iqbal N
    Energy Effic, 2022;15(1):2.
    PMID: 34980948 DOI: 10.1007/s12053-021-10010-z
    Policies on reducing energy demand should incorporate the newly formed economic models, digitalization, and consumer awareness trends. Therefore, this study analyzes the interaction of the three trends with SDG7 under energy efficiency vision 2050, measuring the energy efficiency of OECD from 2005 to 2017 to enable this inclusion. In this context, four new trends expected to shape future energy demand are identified through extensive consultation with experts from South Asian countries by developing future power demand for the year of 2050. Consequently, the results show a crucial impact of such trends on a future power demand that exceeds the economic potential of techno. Hence, the best-case scenario, "New Trends Efficient," reduces final energy demand by 78% compared to the South Asian "Baseline" scenario in 2050, whereas the "Worst Case" scenario increases final energy demand by 35%. Therefore, Austria and Korea have the highest energy efficiency score of 0.76 and 0.75, whereas Canada and Chile have the lowest energy efficiency score of 0.41 and 0.42. This paper discusses the ability of digitalization and energy consumer awareness trends in shaping the future energy demand based on SDG 7, emphasizing the importance of energy efficiency vision 2050 in policymaking for effective acquisition.
  4. Bakhsheshi-Rad HR, Hamzah E, Kasiri-Asgarani M, Jabbarzare S, Iqbal N, Abdul Kadir MR
    Mater Sci Eng C Mater Biol Appl, 2016 Mar;60:526-537.
    PMID: 26706560 DOI: 10.1016/j.msec.2015.11.057
    The present study addressed the synthesis of a bi-layered nanostructured fluorine-doped hydroxyapatite (nFHA)/polycaprolactone (PCL) coating on Mg-2Zn-3Ce alloy via a combination of electrodeposition (ED) and dip-coating methods. The nFHA/PCL composite coating is composed of a thick (70-80 μm) and porous layer of PCL that uniformly covered the thin nFHA film (8-10 μm) with nanoneedle-like microstructure and crystallite size of around 70-90 nm. Electrochemical measurements showed that the nFHA/PCL composite coating presented a high corrosion resistance (R(p)=2.9×10(3) kΩ cm(2)) and provided sufficient protection for a Mg substrate against galvanic corrosion. The mechanical integrity of the nFHA/PCL composite coatings immersed in SBF for 10 days showed higher compressive strength (34% higher) compared with the uncoated samples, indicating that composite coatings can delay the loss of compressive strength of the Mg alloy. The nFHA/PCL coating indicted better bonding strength (6.9 MPa) compared to PCL coating (2.2 MPa). Immersion tests showed that nFHA/PCL composite-coated alloy experienced much milder corrosion attack and more nucleation sites for apatite compared with the PCL coated and uncoated samples. The bi-layered nFHA/PCL coating can be a good alternative method for the control of corrosion degradation of biodegradable Mg alloy for implant applications.
  5. Almasi D, Iqbal N, Sadeghi M, Sudin I, Abdul Kadir MR, Kamarul T
    Int J Biomater, 2016;2016:8202653.
    PMID: 27127513 DOI: 10.1155/2016/8202653
    There is an increased interest in the use of polyether ether ketone (PEEK) for orthopedic and dental implant applications due to its elastic modulus close to that of bone, biocompatibility, and its radiolucent properties. However, PEEK is still categorized as bioinert due to its low integration with surrounding tissues. Many studies have reported on methods to increase the bioactivity of PEEK, but there is still one-preparation method for preparing bioactive PEEK implant where the produced implant with desirable mechanical and bioactivity properties is required. The aim of this review is to present the progress of the preparation methods for improvement of the bioactivity of PEEK and to discuss the strengths and weaknesses of the existing methods.
  6. Saud SN, Hosseinian S R, Bakhsheshi-Rad HR, Yaghoubidoust F, Iqbal N, Hamzah E, et al.
    Mater Sci Eng C Mater Biol Appl, 2016 Nov 01;68:687-694.
    PMID: 27524069 DOI: 10.1016/j.msec.2016.06.048
    In the present work, the microstructure, corrosion, and bioactivity of graphene oxide (GO) coating on the laser-modified and -unmodified surfaces of TiNb shape memory alloys (SMAs) were investigated. The surface morphology and chemical composition was examined using field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The surface modification was carried out via a femtosecond laser with the aim to increase the surface roughness, and thus increase the adhesion property. FE-SEM analysis of the laser-treated Ti-30at.% Nb revealed the increase in surface roughness and oxygen/nitrogen containing groups on the Ti-30at.% Nb surface after being surface modified via a femtosecond laser. Furthermore, the thickness of GO was increased from 35μm to 45μm after the surface was modified. Potentiodynamic polarisation and electrochemical impedance spectroscopy studies revealed that both the GO and laser/GO-coated samples exhibited higher corrosion resistance than that of the uncoated TiNb SMA sample. However, the laser/GO-coated sample presented the highest corrosion resistance in SBF at 37°C. In addition, during soaking in the simulated body fluid (SBF), both the GO and laser/GO coating improved the formation of apatite layer. Based on the bioactivity results, the GO coating exhibited a remarkable antibacterial activity against gram-negative bacteria compared with the uncoated. In conclusion, the present results indicate that Ti-30at.% Nb SMAs may be promising alternatives to NiTi for certain biomedical applications.
  7. Irfan M, Ahmad M, Fareed Z, Iqbal N, Sharif A, Wu H
    PMID: 33448868 DOI: 10.1080/09603123.2021.1874888
    The aim of this study is to identify and highlight the positive and negative indirect environmental impacts of COVID-19, with a particular focus on the most affected economies (USA, China, Spain, and Italy). In this respect, the empirical and theoretical dimensions of the contents of those impacts are analyzed. Research findings reveal a significant relationship between contingency actions and positive indirect impacts such as air quality improvements, clean beaches, and the decline in environmental noise. Besides, negative indirect impacts also exist, such as the rise in waste level and curtailment in recycling, further threatening the physical spaces (land and water), besides air. It is expected that global businesses will revive in the near future (though slowly), but the reduction in greenhouse gas emissions during this short time span is not a sustainable way of environmental mitigation. Thus, long-term mitigation policies should be strengthened to cope with the undesirable deterioration of the environment. Research findings provide an up-to-date glimpse of the pandemic from the perspectives of current and future indirect environmental impacts and the post-pandemic situation. Finally, it is suggested to invent and prepare action plans to induce a sustainable economic and environmental future in the post-pandemic world scenario.
  8. Ali H, Musharraf SG, Iqbal N, Adhikari A, Abdalla OM, Ahmed Mesaik M, et al.
    Int Immunopharmacol, 2015 Sep;28(1):235-43.
    PMID: 26093268 DOI: 10.1016/j.intimp.2015.06.009
    Sarcococca saligna methanolic extract, fractions and isolated pure compounds saracocine (1), saracodine (2), pachyximine-A (3) and terminaline (4) were found to possess potent immunosuppressive activities. The fractions and compounds were tested in-vitro for their effects on human T-cell proliferation, and cytokine (IL-2) production. All the fractions, sub-fractions and purified compounds showed significant suppressive effect on IL-2 production in a dose-dependent manner. They also exhibited a suppressive effect on the phytohemagglutinin-stimulated T-cell proliferation. None of the extracts and purified compounds showed any cytotoxicity effects on the 3T3 mice fibroblast cell line. The crude extract, DCM fraction (pH9), DCM fractions (pH7) and one of the steroidal alkaloids (terminaline) were checked in-vivo for their hepato-protective potential against CCl4-induced liver injury. In in-vivo experiments, the basic and neutral DCM fractions and terminaline (4) significantly reduced inflammation in the liver. DCM fraction (pH9), DCM fractions (pH7) and compound 4 reduced the serum enzyme levels (ALT, AST, and ALP) down to control levels despite CCl4 treatment. They also reduced the CCl4-induced damaged area to almost zero as assessed by histopathology. The pale necrotic areas and mixed inflammatory infiltrate which are seen after CCl4 treatment were absent in the cases of basic, neutral fractions and terminaline treatment. These hepato-protective effects were better than the positive control silymarin. Our results suggest the therapeutic effect of S. saligna extract, fractions and bioactive steroidal alkaloids against CCl4-induced liver injury in vivo and their immunosuppressive function in vitro.
  9. Sarian MN, Iqbal N, Sotoudehbagha P, Razavi M, Ahmed QU, Sukotjo C, et al.
    Bioact Mater, 2022 Jun;12:42-63.
    PMID: 35087962 DOI: 10.1016/j.bioactmat.2021.10.034
    Magnesium alloys are considered the most suitable absorbable metals for bone fracture fixation implants. The main challenge in absorbable magnesium alloys is their high corrosion/degradation rate that needs to be controlled. Various coatings have been applied to magnesium alloys to slow down their corrosion rates to match their corrosion rate to the regeneration rate of the bone fracture. In this review, a bioactive coating is proposed to slow down the corrosion rate of magnesium alloys and accelerate the bone fracture healing process. The main aim of the bioactive coatings is to enhance the direct attachment of living tissues and thereby facilitate osteoconduction. Hydroxyapatite, collagen type I, recombinant human bone morphogenetic proteins 2, simvastatin, zoledronate, and strontium are six bioactive agents that show high potential for developing a bioactive coating system for high-performance absorbable magnesium bone implants. In addition to coating, the substrate itself can be made bioactive by alloying magnesium with calcium, zinc, copper, and manganese that were found to promote bone regeneration.
  10. Sharifi R, Almasi D, Sudin IB, Abdul Kadir MR, Jamshidy L, Amiri SM, et al.
    Int J Biomater, 2018;2018:9607195.
    PMID: 30154853 DOI: 10.1155/2018/9607195
    The mechanical properties of coated layers are one of the important factors for the long-term success of orthopeadic and dental implants. In this study, the mechanical properties of the porous coated layer were examined via scratch and nanoindentation tests. The effect of compression load on the porous coated layer of sulphonated poly ether ether ketone/Hydroxyapatite was studied to determine whether it changes its mechanical properties. The water contact angle and surface roughness of the compressed coated layer were also measured. The results showed a significant increase in elastic modulus, with mean values ranging from 0.464 GPa to 1.199 GPa (p<0.05). The average scratch hardness also increased significantly from 69.9 MPa to 95.7 MPa after compression, but the surface roughness and wettability decreased significantly (p<0.05). Simple compression enhanced the mechanical properties of the sulphonated poly ether ether ketone/hydroxyapatite coated layer, and the desired mechanical properties for orthopaedic and dental implant application can be achieved.
  11. Naqvi SR, Hameed Z, Tariq R, Taqvi SA, Ali I, Niazi MBK, et al.
    Waste Manag, 2019 Feb 15;85:131-140.
    PMID: 30803566 DOI: 10.1016/j.wasman.2018.12.031
    This study investigates the thermal decomposition, thermodynamic and kinetic behavior of rice-husk (R), sewage sludge (S) and their blends during co-pyrolysis using thermogravimetric analysis at a constant heating rate of 20 °C/min. Coats-Redfern integral method is applied to mass loss data by employing seventeen models of five major reaction mechanisms to calculate the kinetics and thermodynamic parameters. Two temperature regions: I (200-400 °C) and II (400-600 °C) are identified and best fitted with different models. Among all models, diffusion models show high activation energy with higher R2(0.99) of rice husk (66.27-82.77 kJ/mol), sewage sludge (52.01-68.01 kJ/mol) and subsequent blends (45.10-65.81 kJ/mol) for region I and for rice husk (7.31-25.84 kJ/mol), sewage sludge (1.85-16.23 kJ/mol) and blends (4.95-16.32 kJ/mol) for region II, respectively. Thermodynamic parameters are calculated using kinetics data to assess the co-pyrolysis process enthalpy, Gibbs-free energy, and change in entropy. Artificial neural network (ANN) models are developed and employed on co-pyrolysis thermal decomposition data to study the reaction mechanism by calculating Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and coefficient of determination (R2). The co-pyrolysis results from a thermal behavior and kinetics perspective are promising and the process is viable to recover organic materials more efficiently.
  12. Taha M, Imran S, Salahuddin M, Iqbal N, Rahim F, Uddin N, et al.
    Bioorg Chem, 2021 05;110:104808.
    PMID: 33756236 DOI: 10.1016/j.bioorg.2021.104808
    We have synthesized new hybrid class of indole bearing sulfonamide scaffolds (1-17) as α-glucosidase inhibitors. All scaffolds were found to be active except scaffold 17 and exhibited IC50 values ranging from 1.60 to 51.20 µM in comparison with standard acarbose (IC50 = 42.45 µM). Among the synthesized hybrid class scaffolds 16 was the most potent analogue with IC50 value 1.60 μM, showing many folds better potency as compared to standard acarbose. Whereas, synthesized scaffolds 1-15 showed good α-glucosidase inhibitory potential. Based on α-glucosidase inhibitory effect, Scaffold 16 was chosen due to highest activity in vitro for further evaluation of antidiabetic activity in Streptozotocin induced diabetic rats. The Scaffold 16 exhibited significant antidiabetic activity. All analogues were characterized through 1H, 13CNMR and HR MS. Structure-activity relationship of synthesized analogues was established and confirmed through molecular docking study.
  13. Taha M, Sain AA, Ali M, Anouar EH, Rahim F, Ismail NH, et al.
    Bioorg Chem, 2020 06;99:103819.
    PMID: 32325334 DOI: 10.1016/j.bioorg.2020.103819
    Leishmaniasis has affected a wider part of population around the globe. Most often, the existing regiments to battle against leishmaniasis are inadequate and limited. In our ongoing efforts to develop new leishmanicidal agents, we have synthesized a series of novel and symmetrical bis-Schiff base-disulfide hybrids 1-27. Intermediate disulfide was synthesized from corresponding 2-aminothiol followed by reacting the coupled adduct with various aromatic aldehydes. All these compounds showed outstanding inhibition when compared with standard (Table 1). Out of twenty seven analogues, twenty two analogues i.e. 1-5, 7-13, 17-21, 23-27 analogues showed excellent inhibitory potential with EC50 values ranging from 0.010 ± 0.00 to 0.096 ± 0.01 μM while five compounds i.e. 6, 14-16, and 22 showed good inhibitory potential with EC50 values ranging from 0.10 ± 0.00 to 0.137 ± 0.01 μM when compared with the standard Amphotericin B. Structure-activity relationship has been established while molecular docking studies were performed to pin the binding interaction of active molecules. This study will help to develop new antileishmanial lead compounds.
  14. Alomari M, Taha M, Rahim F, Selvaraj M, Iqbal N, Chigurupati S, et al.
    Bioorg Chem, 2021 03;108:104638.
    PMID: 33508679 DOI: 10.1016/j.bioorg.2021.104638
    A series of nineteen (1-19) indole-based-thiadiazole derivatives were synthesized, characterized by 1HNMR, 13C NMR, MS, and screened for α-glucosidase inhibition. All analogs showed varied α-glucosidase inhibitory potential with IC50 value ranged between 0.95 ± 0.05 to 13.60 ± 0.30 µM, when compared with the standard acarbose (IC50 = 1.70 ± 0.10). Analogs 17, 2, 1, 9, 7, 3, 15, 10, 16, and 14 with IC50 values 0.95 ± 0.05, 1.10 ± 0.10, 1.30 ± 0.10, 1.60 ± 0.10, 2.30 ± 0.10, 2.30 ± 0.10, 2.80 ± 0.10, 4.10 ± 0.20 and 4.80 ± 0.20 µM respectively showed highest α-glucosidase inhibition. All other analogs also exhibit excellent inhibitory potential. Structure activity relationships have been established for all compounds primarily based on substitution pattern on the phenyl ring. Through molecular docking study, binding interactions of the most active compounds were confirmed. We further studied the kinetics study of analogs 1, 2, 9 and 17 and found that they are Non-competitive inhibitors.
  15. Taha M, Alrashedy AS, Almandil NB, Iqbal N, Anouar EH, Nawaz M, et al.
    Int J Biol Macromol, 2021 Nov 01;190:301-318.
    PMID: 34481854 DOI: 10.1016/j.ijbiomac.2021.08.207
    In this study, we have investigated a series of indole-based compounds for their inhibitory study against pancreatic α-amylase and intestinal α-glucosidase activity. Inhibitors of carbohydrate degrading enzymes appear to have an essential role as antidiabetic drugs. All analogous exhibited good to moderate α-amylase (IC50 = 3.80 to 47.50 μM), and α-glucosidase inhibitory interactions (IC50 = 3.10-52.20 μM) in comparison with standard acarbose (IC50 = 12.28 μM and 11.29 μM). The analogues 4, 11, 12, 15, 14 and 17 had good activity potential both for enzymes inhibitory interactions. Structure activity relationships were deliberated to propose the influence of substituents on the inhibitory potential of analogues. Docking studies revealed the interaction of more potential analogues and enzyme active site. Further, we studied their kinetic study of most active compounds showed that compounds 15, 14, 12, 17 and 11 are competitive for α-amylase and non- competitive for α-glucosidase.
  16. Zaman K, Rahim F, Taha M, Sajid M, Hayat S, Nawaz M, et al.
    Bioorg Chem, 2021 10;115:105199.
    PMID: 34329995 DOI: 10.1016/j.bioorg.2021.105199
    Synthesis of quinoline analogs and their urease inhibitory activities with reference to the standard drug, thiourea (IC50 = 21.86 ± 0.40 µM) are presented in this study. The inhibitory activity range is (IC50 = 0.60 ± 0.01 to 24.10 ± 0.70 µM) which displayed that it is most potent class of urease inhibitor. Analog 1-9, and 11-13 emerged with many times greater antiurease potential than thiourea, in which analog 1, 2, 3, 4, 8, 9, and 11 (IC50 = 3.50 ± 0.10, 7.20 ± 0.20, 1.30 ± 0.10, 2.30 ± 0.10, 0.60 ± 0.01, 1.05 ± 0.10 and 2.60 ± 0.10 µM respectively) were appeared the most potent ones among the series. In this context, most potent analogs such as 1, 3, 4, 8, and 9 were further subjected for their in vitro antinematodal study against C. elegans to examine its cytotoxicity under positive control of standard drug, Levamisole. Consequently, the cytotoxicity profile displayed that analogs 3, 8, and 9 were found with minimum cytotoxic outline at higher concentration (500 µg/mL). All analogs were characterized through 1H NMR, 13C NMR and HR-EIMS. The protein-ligand binding interaction for most potent analogs was confirmed via molecular docking study.
  17. Khan AA, Rahim F, Taha M, Rehman W, Iqbal N, Wadood A, et al.
    Int J Biol Macromol, 2022 Feb 28;199:77-85.
    PMID: 34968547 DOI: 10.1016/j.ijbiomac.2021.12.147
    Triazinoindole bearing thiadiazole derivatives (1-25) have been synthesized and characterized through different spectroscopic techniques such as 1H, 13C-NMR and HREI-MS. The purpose of the study was to investigate the anti-diabetic activity of the synthesized triazinoindole bearing thiadiazole derivatives by inhibition of α-glucosidase. All synthesized analogues showed outstanding inhibition of α-glucosidase enzyme with IC50 values ranging from 2.5 ± 0.10 to 38.10 ± 0.10 µM as compared to the standard drug acarbose (IC50 = 38.45 ± 0.80 µM). Analogue 4 (IC50 = 2.5 ± 0.10 µM) was identifies as the most potent analogue in the series with fifteen folds more active than standard acarbose. Structure activity relationship (SAR) studies suggested that α-glucosidase activities of triazinoindole bearing thiadiazole are primarily dependent upon on number and position of different substitutions present on phenyl parts. Molecular docking study were conducted of the optimized compounds (i.e., compound 4, 6, and 3 etc. using MOE default parameters), the results revealed that compound 4, 6, and 3 showed numerous key interactions with the target protein, which indicate the high potential of these compounds against the target compound. All these compounds were screened for cytotoxic activity against normal normal Vero cell line and found non-toxic.
  18. Jovanović V, Rudnev M, Arslan G, Buzea C, Dimitrova R, Góngora V, et al.
    Appl Res Qual Life, 2022 Jan 24.
    PMID: 35096193 DOI: 10.1007/s11482-021-10024-w
    Measurement of adolescent life satisfaction across cultures has not received much attention in previous empirical research. The present study evaluated measurement invariance of the Satisfaction with Life Scale (SWLS) among adolescents in 24 countries and regions (N = 22,710; age range = 13-19 years; 53% female). A single-factor model with residual covariance between a pair of items tapping past life satisfaction fitted well in 19 countries and regions and showed a partial metric invariance. In a subset of nine countries and regions, partial scalar invariance was supported. Partial metric invariance across all 24 countries and regions was achieved when custom model modifications in five countries and regions were included. Three SWLS items showed evidence of noninvariance across cultures. The measurement model was found to operate similarly across gender and age. Our findings suggest that caution is needed when using the SWLS for measuring life satisfaction among adolescents from different cultures.

    Supplementary Information: The online version contains supplementary material available at 10.1007/s11482-021-10024-w.

Filters
Contact Us

Please provide feedback to Administrator (tengcl@gmail.com)

External Links