37 results on '"Saba Zahid"'
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2. Credit Card Fraud Detection using Deep Learning and Machine Learning Algorithms
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Saba Zahid, Saba Zahid, primary, Hafiz Muhammad Usman Hafeez, Hafiz Muhammad Usman Hafeez, additional, Muhammad Javaid Iqbal, Muhammad Javaid Iqbal, additional, Ali Asif, Ali Asif, additional, Sobia Yaqoob, Sobia Yaqoob, additional, and Fozia Mehboob, Fozia Mehboob, additional more...
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- 2024
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Catalog
3. Novel A-π-D-π-A type non-fullerene acceptors of dithienyl diketopyrropopyrrole derivatives to enhance organic photovoltaic applications: a DFT study
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Mafia Rani, N. M. A. Hadia, Ahmed M. Shawky, Rana Farhat Mehmood, Shanza Hameed, Saba Zahid, Javed Iqbal, Naifa S. Alatawi, Asma Ahmed, and Rasheed Ahmad Khera
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General Chemical Engineering ,General Chemistry - Abstract
The investigated non-fullerene acceptor molecules TM1, TM2, TM3, TM4, TM5, TM6, and TM7 that are fashioned by making alterations at the terminal position of reference molecule TMR demonstrate significant absorption in the visible region. more...
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- 2023
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4. Environmentally compatible and highly improved hole transport materials (HTMs) based on benzotrithiophene (BTT) skeleton for perovskite as well as narrow bandgap donors for organic solar cells
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Saba Zahid, Alvina Rasool, Muhammad Ans, Mohammed Salim Akhter, Javed Iqbal, M.S. Al-Buriahi, Sultan Alomairy, and Z.A. Alrowaili
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Renewable Energy, Sustainability and the Environment ,General Materials Science - Published
- 2022
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5. Bithieno Thiophene-Based Small Molecules for Application as Donor Materials for Organic Solar Cells and Hole Transport Materials for Perovskite Solar Cells
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Shabbir Muhammad, Muhammad Ans, Javed Iqbal, Saba Zahid, Khurshid Ayub, and Alvina Rasool
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Chemistry ,General Chemical Engineering ,General Chemistry ,QD1-999 ,Article - Abstract
This quantum mechanical study focuses on the designing of twelve (MPAM1–MPAM12) bithieno thiophene (BTTI) central core-based small molecules to explore optoelectronic properties as donor candidates for organic solar cells (OSCs) and hole transport materials (HTMs) accompanied by enhanced charge mobility for perovskite solar cells (PSCs). MPAM1–MPAM6 have been designed by the substitution of thiophene-bridged end-capped acceptors on both side terminals of reference (MPAR). MPAM7–MPAM12 are tailored by adopting the same tactic on one side terminal only. MPW1PW91/6-311G (d,p) has been employed for all computational simulations. MPAM12 revealed the highest λmax at 639 nm in dichloromethane (DCM) solvent with the lowest Eg of 1.78 eV and dipole moment (20.74 D) in the solvent phase, showing excellent miscibility as compared to the reference. All designed chromophores (MPAM1–MPAM12) demonstrated higher estimated VOC and power conversion efficiency (PCE) when compared to MPAR, suggesting their prominent operational efficiency. Among all, MPAM4 manifested the highest PCE (47.86%). MPAM2 portrayed the highest electron mobility (0.0041573 eV) and MPAM3 exhibited the highest hole mobility (0.0047178 eV). The outcomes highlight the adequacy of the planned strategies, paving a new route for the development of small-molecule HTMs for PSCs and donor contributors for OSCs. more...
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- 2021
6. Quantum Chemical Approach of Donor−π–Acceptor Based Arylborane–Arylamine Macrocycles with Outstanding Photovoltaic Properties Toward High-Performance Organic Solar Cells
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Saba Zahid, Muhammad Yaseen, Javed Iqbal, Muhammad Ans, and Alvina Rasool
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Quantum chemical ,Fuel Technology ,Materials science ,Organic solar cell ,General Chemical Engineering ,Photovoltaic system ,Energy Engineering and Power Technology ,Photochemistry ,Acceptor - Published
- 2021
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7. Organic Semiconductors for Photovoltaics
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Rao Aqil Shehzad, Saba Zahid, Alvina Rasool, and Javed Iqbal
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- 2022
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8. Molecular Modeling of Pentacyclic Aromatic Bislactam-Based Small Donor Molecules by Altering Auxiliary End-Capped Acceptors to Elevate the Photovoltaic Attributes of Organic Solar Cells
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Mahnoor Qaisar, Saba Zahid, Rasheed Ahmad Khera, Yaser A. El-Badry, Muhammad Umar Saeed, Rana Farhat Mehmood, and Javed Iqbal
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General Chemical Engineering ,General Chemistry - Abstract
Small-molecule (SM)-based organic solar cells (OSCs) have dominated the photovoltaic industry on account of their efficient optical and electronic properties. This quantum mechanical study addresses a DFT study of pentacyclic aromatic bislactam (PCL)-based small molecules for extremely proficient OSCs. Five novel small molecules ( more...
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- 2022
9. Silver cluster doped graphyne (GY) with outstanding non-linear optical properties
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Saba Zahid, Alvina Rasool, Ali Raza Ayub, Khurshid Ayub, Javed Iqbal, M. S. Al-Buriahi, Norah Alwadai, and H. H. Somaily
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General Chemical Engineering ,General Chemistry - Abstract
This research study addresses the computational simulations of optical and nonlinear optical (NLO) characteristics of silver (Ag) cluster doped graphyne (GY) complexes. By precisely following DFT and TD-DFT hypothetical computations, in-depth characterization of GY@Ag more...
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- 2021
10. Theoretical study of [36]adamanzane (36Adz) based alkalides with remarkable non-linear optical properties
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Alvina Rasool, Saba Zahid, Abraham Elmushyakhi, Muhammad Ans, Ahmed M. Shawky, Khurshid Ayub, and Javed Iqbal
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Condensed Matter Physics ,Mathematical Physics ,Atomic and Molecular Physics, and Optics - Abstract
Herein, a series of 36Adamanzane (stable C–N bond) based alkalides possessing alkaline Earth metal cation complexed by the 36Adz cage has been designed and studied with theoretical tools. All suggested complexes are within the range of effective NLO materials such as red-shifted λ max (1080–1241 nm), narrowed Eg (1.74 to 2.31 eV), lowered Eopt (0.9945–1.1485 eV), enhanced Δ μ (5.3873–6.2544 au), ameliorated α O (454.20–1400.34 au) and β 0 (801301.48–819800.06 au) as compared to pure 36Adz (Eg = 10.2 eV, λ max = 179 nm, Eopt = 6.9217, α O = 241.64 and β 0 = 0.02 au). All of the aimed complexes have substantially large α O as well as β 0 values. NBO charges investigations reveal that one of the s-electrons has migrated from the inside metal atom to the outer one, resulting in not only alkalide characteristics but also significant NLO responses for the targeted compounds. This research is useful in the development of new types of excess electron compounds. The findings presented in this study may have implications for future research on high-performance NLO materials, as well as give important references for future research on various alkalides including non-alkali cations. more...
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- 2023
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11. DFT study of super-halogen (Al7) doped carbon nitride (C2N) and its nonlinear optical properties
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Abid Hussain, N.M.A. Hadia, M.M. Hessien, Rasheed Ahmad Khera, Saba Zahid, Rao Aqil Shehzad, Ali Raza Ayub, Khurshid Ayub, and Javed Iqbal
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Inorganic Chemistry ,Organic Chemistry ,Spectroscopy ,Analytical Chemistry - Published
- 2022
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12. Tuning the optoelectronic properties of triphenylamine (TPA) based small molecules by modifying central core for photovoltaic applications
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Ijaz Ahmad Bhatti, Alvina Rasool, Rao Aqil Shehzad, Saba Zahid, and Javed Iqbal
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Materials science ,Organic solar cell ,Band gap ,Organic Chemistry ,Time-dependent density functional theory ,Triphenylamine ,Photochemistry ,Acceptor ,Catalysis ,Computer Science Applications ,Inorganic Chemistry ,chemistry.chemical_compound ,Computational Theory and Mathematics ,chemistry ,Electron affinity (data page) ,Bathochromic shift ,Molecule ,Physical and Theoretical Chemistry - Abstract
Small donor molecules based on fused ring acceptors exhibit encouraging photovoltaic properties and expeditious advancement in organic solar cells. Central core modification of non-fullerene acceptor materials is a favorable methodology to enhance electronic properties and efficiency for OSCs. Herein, four new donor molecules, namely, BDTM1, PYRM2, ANTM3, and NM4 are designed with a strong donor moiety triphenylamine, tetracyanobutadiene as acceptor unit, and thiophene as spacer linked to a modified central core. Geometric parameters, optical, electrical properties, effect of central core modification on tailored molecules BDTM1-NM4 are investigated and compared with reference DPPR. DFT together with TDDFT approaches using MPW1PW91 functional is used to study key parameters like absorption maximum (λmax), frontier molecular approach, ionization potential, electron affinity, the density of states, transition density matrix along with open-circuit voltage (VOC), dipole moment and reorganization energy. Among all these molecules, BDTM1 shows maximum calculated absorption λmax (817 nm) and the lowest band gap (2.54 eV). This bathochromic shift in BDTM1 is due to the presence of 4,8-dimethoxy-2,6-di-2-thienylbenzodithiophene as a strong electron-withdrawing group. Computed reorganization energies (RE) shows that BDTM1 has the highest hole and electron mobility among all designed molecules. Combination of BDTM1 donor and PC61BM acceptor further verifies charge transfer and their interaction. The results illustrate that designed donor molecules (BDTM1-NM4) are better in performance and are recommended for experimentation to develop efficient OSCs. Four new donor molecules, namely, BDTM1, PYRM2, ANTM3, and NM4 are designed with a strong donor moiety triphenylamine, tetracyanobutadiene as acceptor unit and thiophene as spacer linked to a modified central core. Geometric parameters, optical, electrical properties, effect of central core modification on tailored molecules BDTM1-NM4 are investigated and compared with reference DPPR. more...
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- 2021
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13. Relationship between Academic Boredom, Learning Climate and Academic Motivation Among University Students
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Saira Khan, Rayna Sadia, Saba Zahid Hayat, and Sonia Tahir
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Learning climate ,media_common.quotation_subject ,05 social sciences ,050301 education ,050109 social psychology ,Boredom ,Negative relationship ,Scale (social sciences) ,medicine ,Intrinsic motivation ,Positive relationship ,0501 psychology and cognitive sciences ,Correlational analysis ,medicine.symptom ,Psychology ,0503 education ,Social psychology ,General Psychology ,Autonomy ,media_common - Abstract
The present research aimed at exploring the relationship between academic motivation, learning climate (Autonomy supported) and academic boredom among university students. In addition to this it aimed at confirming the mediating role of learning climate in relationship between intrinsic motivation and academic boredom among students studying in Universities of Pakistan. For the present study data was collected from 399 university students. The age of the sample ranged from 17 to 35 years (M = 21.45, SD = 2.40). Reliability coefficients of all the variables ranged from .65-.89 (Class Related Boredom Scale = .89, Learning Climate Questionnaire =.88, Academic Motivation Scale = .82, Intrinsic Motivation = .81, Extrinsic Motivation = .81, and A Motivation =.65). Further correlational analysis indicated a negative relationship of classroom related boredom with learning climate and intrinsic motivation. However, class related boredom was found to have positive relationship with extrinsic and a motivation. Learning climate (autonomy supportive) showed positive relation with intrinsic motivation. Based upon literature, mediation analysis was carried out which confirmed the mediating role of learning climate (autonomy supportive) in relation between intrinsic motivation and academic boredom. In the light of existing literature, findings were discussed, and suggestions were given for future researches. more...
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- 2019
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14. Comparative Physicochemical and Microbiological Assessment of Branded and Unbranded Whole Wheat Flours in Pakistan
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Sajid Husain, Salman Saeed, Abdul Ahid Rashid, Khurram Shahzad, Abida Hassan, Shaista Nawaz, Yasar Saleem, and Saba Zahid
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Wheat flour ,Microbiological quality ,Food science ,Biology ,General Agricultural and Biological Sciences ,Whole wheat - Published
- 2019
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15. Surface-grafted remedial hydroxyapatite nanoparticles to avoid operational infections
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Faiza Zarif, Mazhar Amjad Gilani, Anila Asif, Arshad Jamal, Faiza Sharif, Aqif Anwar Chaudhry, Urooj Gul, Saba Zahid, Ihtesham Ur Rehman, and Sobia Tabassum
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Biocompatibility ,010405 organic chemistry ,medicine.drug_class ,Antibiotics ,General Chemistry ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallinity ,chemistry ,Bromide ,Staphylococcus aureus ,Moxifloxacin ,medicine ,Surface charge ,Antibacterial activity ,Nuclear chemistry ,medicine.drug - Abstract
Development of economical bone repair materials that can avoid bone infections is a necessity. Hydroxyapatite (HA) and grafted hydroxyapatite (g-HA) were prepared by the in situ co-precipitation method and explored for controlled delivery of moxifloxacin. It was revealed that high surface area, surface charge, and low degree of crystallinity of g-HA enhanced its electrostatic interaction with an antibiotic moxifloxacin and improved in vitro release of the drug as compared to pure HA. In vitro antibacterial activity showed that drug release from HA and g-HA was effective against Staphylococcus aureus and Escherichia coli. The biocompatibility of HA and g-HA was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. more...
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- 2019
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16. In-vitro investigation of graphene oxide reinforced bioactive glass ceramics composites
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Oliver Goerke, Kanwal Ilyas, Asma Tufail Shah, Saba Zahid, Aleksander Gurlo, Aqif Anwar Chaudhry, Madeeha Batool, Mian Hasnain Nawaz, Ihtesham Ur Rehman, Farasat Iqbal, and Arshad Jamal
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Materials science ,Composite number ,Oxide ,02 engineering and technology ,01 natural sciences ,Apatite ,law.invention ,chemistry.chemical_compound ,symbols.namesake ,law ,0103 physical sciences ,Materials Chemistry ,Ceramic ,Composite material ,010302 applied physics ,Graphene ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Electronic, Optical and Magnetic Materials ,chemistry ,visual_art ,Bioactive glass ,Ceramics and Composites ,visual_art.visual_art_medium ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
In graphene oxide (GO) reinforced composite materials, the uniform dispersion of GO and its interaction with matrix is highly desired for better mechanical properties. In order to achieve better interlocking and uniform microstructure, ion interaction approach has been used for the synthesis of GO and bioactive glass ceramics (BGC) composites. Oxygenated functional groups of GO played a decisive role in GO and BGC interlocking and towards the uniform homogeneity of the composite. GO-BGC composites with different GO to BGC weight ratios (0.5 to 2.0 wt.-%) were synthesized via the base-catalyzed sol-gel method and characterized by FTIR, RAMAN, SEM, TGA-DSC, and X-Ray diffraction techniques. An increase in micro-hardness was observed with the addition of GO up to 1 wt.-%, however, further loading led to a decrease in hardness. Moreover, GO-BGC composites were thermally more stable as compared to pristine GO. Bio-mineralization studies showed that composites were bioactive and GO supported the formation of the apatite layer. Furthermore, the composites were cytocompatible as was demonstrated by MTT assay using rat mesenchymal stem cells. This study can provide interesting insights into the synthesis and applications of novel composite biomedical materials. more...
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- 2019
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17. Application in decision making based on fuzzy parameterized hypersoft set theory
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Atiqe Ur Rahman, Muhammad Saeed, and Saba Zahid
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Soft set ,Hypersoft set ,Fuzzy soft set ,Fuzzy parameterized soft set - Abstract
Hypersoft set is the generalization of the soft set as it converts single attribute function to multi-attribute function. The core purpose of this study is to make the existing literature regarding fuzzy parameterized soft set in line with the need for multi-attribute function. We first conceptualize the fuzzy parameterized hypersoft set along with some of its fundamentals. Then we propose a decision-making-based algorithm with the help of this theory. Moreover, an illustrative example is presented which depicts its validity for successful application to the problems involving vagueness and uncertainties., {"references":["Zadeh, L. (1965). Fuzzy sets. Information and control, 8(3), 338-353.","Molodtsov, D. (1999). Soft Set Theory - First Results. Comput Math with Appl., 37, 19-31.","Maji. P.K., Biswas R. and Roy, A. R. (2003). Soft Set Theory. Comput Math with Appl., 45, 555-562.","Maji, P. K., Biswas, R. and Roy, A. R. (2001). Fuzzy soft sets. Journal of Fuzzy Mathematics, 9(3), 589–602 .","Pei, D. and Miao, D. (2005). From soft set to information system. In international conference of granular computing IEEE, 2, 617-621.","Ali, M. I., Feng, F., Liu, X., Min, W. K. and Sabir, M. (2009). On some new operations in soft set theory. Comput Math with Appl., 57, 1547-1553.","Babitha, K. V. and Sunil, J. J., (2010). Soft set relations and functions. Comput Math with Appl., 60, 1840-1849.","Babitha, K. V. and Sunil, J. J., (2011). Transitive closure and ordering in soft set. Comput Math with Appl., 61, 2235-2239.","Sezgin, A. and Atagun A. O., (2011). On operations of soft sets. Comput Math with Appl., 61(5), 1457-1467.","Ge, X. and Yang, S. (2011). Investigations on some operations of soft sets. World Academy of Science Engineering and Technology, 75, 1113-1116."]} more...
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- 2021
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18. Enhancement in non-linear optical properties of carbon nitride (C2N) by doping superalkali (Li3O): A DFT study
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Talha Ishfaq, Rasheed Ahmad Khera, Saba Zahid, Umer Yaqoob, Rao Aqil Shehzad, Khurshid Ayub, and Javed Iqbal
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Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2022
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19. Fabrication, in vitro and in vivo studies of bilayer composite membrane for periodontal guided tissue regeneration
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Oliver Goerke, Muhammad Imran Rahim, Ihtesham Ur Rehman, Ahtasham Raza, Abdul Samad Khan, Sarah Ghafoor, Asma Tufail, Aqif Anwar Chaudhry, Qurat Ul Ain, and Saba Zahid
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Male ,animal testing ,Bone Regeneration ,Biocompatibility ,Polyesters ,Polyurethanes ,0206 medical engineering ,Biomedical Engineering ,Biocompatible Materials ,02 engineering and technology ,law.invention ,Biomaterials ,chemistry.chemical_compound ,Tissue engineering ,law ,Cell Line, Tumor ,Animals ,ddc:610 ,Bone regeneration ,Tissue Scaffolds ,immuno-staining ,Regeneration (biology) ,Bilayer ,bioactive glass ,Membranes, Artificial ,guided tissue regeneration ,021001 nanoscience & nanotechnology ,020601 biomedical engineering ,in vitro cytotoxicity ,Rats ,Membrane ,chemistry ,bilayer membrane ,Bioactive glass ,Polycaprolactone ,Guided Tissue Regeneration, Periodontal ,Biophysics ,610 Medizin und Gesundheit ,0210 nano-technology ,Porosity - Abstract
This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively., Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., Development of a guided occlusive biodegradable membrane with controlled morphology in order to restrict the ingrowth of epithelial cells is still a challenge in dental tissue engineering. A bilayer membrane with a non-porous upper layer (polyurethane) and porous lower layer (polycaprolactone and bioactive glass composite) with thermoelastic properties to sustain surgery treatment was developed by lyophilization. Morphology, porosity, and layers attachment were controlled by using the multi-solvent system. In vitro and in vivo biocompatibility, cell attachment, and cell proliferation were analyzed by immunohistochemistry and histology. The cell proliferation rate and cell attachment results showed good biocompatibility of both surfaces, though cell metabolic activity was better on the polycaprolactone-bioactive glass surface. Furthermore, the cells were viable, adhered, and proliferated well on the lower porous bioactive surface, while non-porous polyurethane surface demonstrated low cell attachment, which was deliberately designed and a pre-requisite for guided tissue regeneration/guided bone regeneration membranes. In addition, in vivo studies performed in a rat model for six weeks revealed good compatibility of membranes. Histological analysis (staining with hematoxylin and eosin) indicated no signs of inflammation or accumulation of host immune cells. These results suggested that the fabricated biocompatible bilayer membrane has the potential for use in periodontal tissue regeneration. more...
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- 2018
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20. Sol-gel derived fluoride-doped bioactive glass powders: Structural and long-term fluoride release/pH analysis
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Hashmat Gul, Asma Tufail Shah, Saba Zahid, Shahreen Zahid, Muhammad Kaleem, and Abdul Samad Khan
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Materials science ,Scanning electron microscope ,Fluorapatite ,030206 dentistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Ion selective electrode ,Amorphous solid ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,chemistry ,law ,Bioactive glass ,Materials Chemistry ,Ceramics and Composites ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Fluoride ,Nuclear chemistry ,Sol-gel - Abstract
The study aimed to compare the fluoride release behavior of newly synthesized bioactive glass powders and its effect on the pH. The bioactive glass (BG) and three groups of fluoride-doped (2.5, 5 and 7.5 mol%) bioactive glasses (F-BG) powders were synthesized by a base-catalyzed sol-gel method. The prepared samples were heat-treated and were characterized by Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy, and Brunauer–Emmett–Teller (BET) surface area analyzer. The prepared heat-treated F-BG samples were amorphous in nature, except F-BAG with 2.5 mol% fluoride which was glass-ceramic with few characteristic peaks of fluorapatite and teracalcium phosphate phases. High surface area of these prepared powders were observed, however, it was decreased with the increase in fluoride contents and particle size. A 6 month long fluoride release behavior was studied periodically in deionized water using an Ion Selective Electrode. Fluoride release was maximum with F-BG (7.5% mol.%), however, the insignificant difference was observed among samples. Initially, high pH value was exhibited by all samples, where highest pH was observed with BG and least with F-BAG (5 mol%). The resulting F-BG (5% mol.%) has potential to be used in dentifrices, restorative materials and for other dental applications. more...
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- 2018
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21. Synergistic engineering of end-capped acceptor and bridge on arylborane-arylamine macrocycles to boost the photovoltaic properties of organic solar cells
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Alvina Rasool, Saba Zahid, Muhammad Ans, Javed Iqbal, Muhammad Adnan, El-Sayed M. Sherif, and M.S. Al-Buriahi
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Inorganic Chemistry ,Organic Chemistry ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Atomic and Molecular Physics, and Optics ,Spectroscopy ,Electronic, Optical and Magnetic Materials - Published
- 2022
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22. Designing of benzodithiophene (BDT) based non-fullerene small molecules with favorable optoelectronic properties for proficient organic solar cells
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Muhammed Salim Akhter, Saba Zahid, Rao Aqil Shehzad, Alvina Rasool, and Javed Iqbal
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Organic solar cell ,business.industry ,Band gap ,Time-dependent density functional theory ,Condensed Matter Physics ,Biochemistry ,Acceptor ,chemistry.chemical_compound ,chemistry ,Thiophene ,Molecule ,Optoelectronics ,Molecular orbital ,Density functional theory ,Physical and Theoretical Chemistry ,business - Abstract
To extinguish the thirst of extraordinary tailback in the stock of energy and to jack up the operational effectiveness of organic solar cells, 5 new donor molecules namely BDTM1, BDTM2, BDTM3, BDTM4, BDTM5 have been designed by the structural tailoring of the already experimentally synthesized POBDT-4Cl. POBDT-4Cl is taken as a reference designated as BDTR. All the designed chromophores constitute benzodithiophene as donor and thiophene bridged end-capped (3-methyl-5-methylene-2-thioxothiazolidin-4-one) BDTM1, (2-methylenemalononitrile) BDTM2, (methyl 2-cyanoacrylate) BDTM3, (2-(3-methyl-5-methylene-4-oxothiazolidin-2-ylidene)malononitrile) BDTM4, (4-(5-methylthiophen-2-yl)benzo[c][1,2,5]thiadiazole) BDTM5 acceptor groups. Influence of different terminal acceptor moieties on the molecular orbitals, density of states (DOS), maximum absorption (λmax), energy required for the generation of electron and hole carrier, transition density matrix (TDM), dipole moment, reorganization energy (RE), and open-circuit voltage (VOC) has been inquired via density-functional theory (DFT) and time-dependent density functional theory (TDDFT) methodology using B3LYP/6-31G (d,p) and these afore-mentioned features of newly devised molecules have been compared with the reference (BDTR). Among all newly designed molecules (BDTM1-BDTM5), BDTM1 exhibited the highest λmax value of 725 nm. BDTM3, BDTM4, and BDTM5 have displayed the highest dipole moment than the reference (BDTR). Cation (hole) transport rate of BDTM5 (0.00578 eV) and BDTM2 (0.00632 eV) has been explored lower than BDTR (0.00662 eV). Similarly, BDTM5 has displayed lower anion (electron) transport rate (0.00578 eV) relative to BDTR (0.00603 eV). Among all designed molecules, BDTM5 has expressed formidable and unique results accompanied by the lowest band gap (1.90 eV), comparable λmax (720 nm), and VOC. All newly constructed molecules have exposed enhanced VOC. Briefly, the thiophene bridged end-capped acceptor modification approach has been demonstrated compelling in providing the door to plan profoundly effective photovoltaic materials accompanied by exquisite optoelectronic parameters. more...
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- 2021
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23. Contributors
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Yara Khalid Almaimouni, Nujood Ibrahim Alyousef, Aysha Arshad, Anila Asif, Usaid Azhar, Mashael Abdullah Benrahed, Aqif Anwar Chaudhry, Amber Fareed, Hira Fatima, Sandleen Feroz, Hashmat Gul, Shorouq Khalid Hamid, Shehriar Hussain, Kashif Ijaz, Farasat Iqbal, Hamad Khalid, Abdul Samad Khan, Ather Farooq Khan, Maria Khan, Zohaib Khurshid, Muhammad Maqbool, Ume Omema, Saeed Ur Rahman, Mariam Raza, Franziska Schmidt, Farshid Sefat, Saroash Shahid, Saadat Anwar Siddiqi, Sobia Tabassum, Ahmed Talal, Asma Tufail, Christie Lung Ying Kei, Safiyya Yousaf, Muhammad Sohail Zafar, and Saba Zahid more...
- Published
- 2020
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24. Analytical tools for substituted hydroxyapatite
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Mariam Raza, Saba Zahid, and Anila Asif
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Chemical engineering ,Chemistry ,visual_art ,Biological property ,visual_art.visual_art_medium ,Hard tissue ,Apatite - Abstract
Hydroxyapatite (HA) continues to attract much attention owning to its many potential applications in biomedical field, especially in orthopedics and dentistry, because of its similarity to the composition of mineral component of hard tissue. The ability to exchange ions in apatite structure allows to play with structure–property relation for design and development of ion-substituted calcium phosphates for targeted applications. The influence of the various vicarious ions within the HA provokes structural changes that have key effects related to the physical, microstructural, chemical, and biological properties of the obtained substituted HA. This chapter provides an overview about the analytical tools for majority of the investigated anionic and cationic substitutions within the HA lattice. more...
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- 2020
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25. Smart injectable self-setting bioceramics for dental applications
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Abdul Samad Khan, Qurat ul Ain Malik, Sundus Iftikhar, Ather Farooq Khan, Sher Zaman Safi, Sarah Ghafoor, Asma Tufail Shah, Muhammad Nawshad, and Saba Zahid
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Ceramics ,Materials science ,Scanning electron microscope ,Cell Survival ,Composite number ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Apatite ,law.invention ,Cell Line ,Biomaterials ,Mice ,stomatognathic system ,law ,Dentin ,medicine ,Animals ,Fourier transform infrared spectroscopy ,Bone regeneration ,Dental Implants ,Saliva, Artificial ,Poloxamer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,medicine.anatomical_structure ,Mechanics of Materials ,Bioactive glass ,visual_art ,visual_art.visual_art_medium ,Nanoparticles ,Glass ,0210 nano-technology ,Biomedical engineering - Abstract
A thermo-responsive injectable bioactive glass (BAG) that has the ability to set at body temperature was prepared using pluronic F127 and hydroxypropyl methylcellulose as the carrier. The injectable composite has the advantage to fill irregular shape implantation sites and quick setting at body temperature. The structural and morphological analysis of injectable BAG before and after setting was done by using Fourier Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscope (SEM). The effect of an ultrasonic scaler for a quick setting of injectable BAG was also investigated. The ultrasonic scaler sets the BAG formulation three-folds faster than at body temperature and homogenized the dispersion. The in vitro bio-adhesion was studied in the bovine tooth in both artificial saliva and deionized water for periodic time intervals, i.e., day 7, 30, 90, and 180, which confirmed the apatite layer formation. The mineral density analysis was used to differentiate the newly formed apatite with tooth apatite. In the MTT assay, the experimental material showed continuous proliferation and cell growth. This indicated that injectable hydrogel promoted cell growth, facilitated proliferation, and had no cytotoxic effect. The SEM and micro-CT results (performed after in vitro bioactivity testing) showed that the injectable BAG had the ability to regenerate dentin, hence this material has the potential to be used for dental and biomedical applications including tooth and bone regeneration in minimally invasive procedures in future. more...
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- 2019
26. Physical, mechanical, and in vitro biological analysis of bioactive fibers‐based dental composite
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Mehvish Saleem, Sarfraz Ahmad, Saba Zahid, Anila Asif, Hina Khalid, Abdul Samad Khan, Rabia Zeeshan, Haffsah Iqbal, and Sarah Ghafoor
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Dental composite ,Materials science ,Polymers and Plastics ,Biocompatibility ,Materials Chemistry ,General Chemistry ,In vitro ,Surfaces, Coatings and Films ,Biomedical engineering - Published
- 2020
- Full Text
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27. Tri-layered functionally graded membrane for potential application in periodontal regeneration
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Oliver Goerke, Abdul Samad Khan, Fakhera Ikram, Ihtesham Ur Rehman, Asma Tufail Shah, Franziska Schmidt, Saba Zahid, Aqif Anwar Chaudhry, Muhammad Imran Rahim, and Muhammad Maqbool
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Materials science ,Biocompatibility ,Bioengineering ,Biocompatible Materials ,02 engineering and technology ,Poloxamer ,010402 general chemistry ,01 natural sciences ,law.invention ,Biomaterials ,Chitosan ,Contact angle ,chemistry.chemical_compound ,Mice ,X-Ray Diffraction ,law ,In vivo ,Materials Testing ,Spectroscopy, Fourier Transform Infrared ,medicine ,Cell Adhesion ,Animals ,Rats, Wistar ,Dental Implants ,Osteoblasts ,Guided Tissue Regeneration ,Osteoblast ,Membranes, Artificial ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,medicine.anatomical_structure ,Membrane ,chemistry ,Mechanics of Materials ,Bioactive glass ,Biophysics ,Microscopy, Electron, Scanning ,Nanoparticles ,Glass ,0210 nano-technology - Abstract
A novel tri-layered, functionally-graded chitosan membrane (FGM) with bioactive glass gradient (50%, 25%, and 0% wt.) was developed by lyophilization. A step-wise grading of chitosan, bioactive glass (BG), and Pluronic F127 was introduced into the membrane in which each layer has separate surface functions that play a role of guided tissue regeneration (GTR) membranes. The lower layer was designed to replicate alveolar bone and contains 50%wt. BG, the middle layer contains 25%wt. BG, while the upper layer was non-porous without BG and it did not support cell growth. Scanning Electron Microscopy (SEM) revealed that the lower FGM surface possessed a porous structure with embedded BG particles, while the upper surface was non-porous with interconnected architecture. The contact angle measurement confirmed that the surface with BG was hydrophilic (≈00), while the opposite surface was hydrophobic (910 ± 3.840). Both osteoblast and fibroblast cells have maximum adhesion at contact angle more...
- Published
- 2019
28. Bi-layered α-tocopherol acetate loaded membranes for potential wound healing and skin regeneration
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Lubna Shahzadi, Asma Tufail Shah, Fakhera Ikram, Hamad Khalid, Ather Farooq Khan, Haffsah Iqbal, Sana Javaid Awan, Aqif Anwar Chaudhry, Ihtesham Ur Rehman, Muhammad Yar, Muhammad Samie, and Saba Zahid more...
- Subjects
Materials science ,Cell Survival ,Polyesters ,alpha-Tocopherol ,Bioengineering ,Biocompatible Materials ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biomaterials ,chemistry.chemical_compound ,Polylactic acid ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,Viability assay ,Cell adhesion ,Cell Proliferation ,Skin ,Wound Healing ,Tissue Engineering ,Tissue Scaffolds ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Membrane ,chemistry ,Mechanics of Materials ,Nanofiber ,Polycaprolactone ,Biophysics ,Microscopy, Electron, Scanning ,Swelling ,medicine.symptom ,0210 nano-technology ,Wound healing - Abstract
With an increase in the demand for skin regeneration products, there is a noticeable increase in developing materials that encourage, wound healing and skin regeneration. It has been reported that antioxidants play an important role in anti-inflammatory reactions, cellular proliferation and remodeling phase of wound healing. While consideration all these factors, a novel α-tocopherol acetate (vitamin E) (VE) loaded bi-layered electrospun membrane, based on lower polycaprolactone (PCL) layer and upper polylactic acid (PLA) layer, was fabricated through electrospinning. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), in-vitro degradation studies, swelling studies and VE release studies were performed to evaluate structural, physical and in-vitro behavior of membranes. Biological properties of membranes were evaluated through cell proliferation assay, cell adhesion studies, live/dead cell assay and CAM assay. SEM images showed that the average diameter of nanofibers ranged from 1 to 6 μm, while addition of VE changed the diameter and morphology of fibers. Bi-layered membranes showed significant swelling behavior through water uptake, membranes loaded with 30% VE showed 8.7% and 6.8% degradation in lysozyme and H2O2 respectively. 20% and 30% VE loaded membranes followed Korsmeyer-Peppas and first order drug release kinetics followed by non-fickian drug release kinetics. Membranes showed non-toxic behavior and supported cell proliferation via alamar blue assay, cell adhesion via SEM, cell viability via live/dead assay and wound healing by scratch assay. CAM assay showed that membranes having VE supported angiogenesis and showed significant formation of blood vessels making it suitable for skin regeneration and wound healing. Results showed that large surface area of nanofibers, porous structure and biocompatible nature are suitable for targeted clinical applications. more...
- Published
- 2018
29. Efficient drug delivery system for bone repair by tuning the surface of hydroxyapatite particles
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Aqif Anwar Chaudhry, Arshad Jamal, Faisal Manzoor, Ihtesham Ur Rehman, Mazhar Amjad Gilani, Sobia Tabassum, Fozia Rehman, Faiza Zarif, Saba Zahid, and Saadat Anwar Siddiqi
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Adipic acid ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,Malonic acid ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Succinic acid ,Drug delivery ,Surface modification ,Organic chemistry ,Stearic acid ,0210 nano-technology ,Nuclear chemistry ,BET theory - Abstract
A limited blood flow to skeletal tissues results in minimal therapeutic effect of drugs being administered to a patient using conventional ways. To obtain sufficient amount of drug at an effected site, implanted drug delivery systems based on biomaterials can be used. In this study, surface modified hydroxyapatites (m-HA) were prepared and evaluated as drug delivery systems. The effect of modifiers on surface properties of HA and their in vitro drug delivery efficiency were investigated. For synthesis of m-HA, a simple in situ co-precipitation method was used. Hydroxyapatite was subjected to surface modification by various carboxylic acids such as adipic acid, malonic acid, succinic acid and stearic acid. This surface modification affected its surface properties such as surface area, pore size, pore volume, particle size and crystallinity. The m-HA were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Brunauer–Emmett–Teller (BET) technique was used to compute surface properties of m-HA. The highest BET surface area of 143 m2 g−1 has been found for HA modified with malonic acid and the lowest surface area of 37 m2 g−1 was calculated for stearic acid modified HA. The BET adsorption average pore size (17–20 nm) of m-HA confirmed its mesoporous nature. The biocompatible nature of the prepared m-HA was assessed by 3-(4,5)-dimethylthiahiazo(-z-yl)-3,5-di-phenytetrazoliumromide (MTT) assay. To evaluate the influence of functional groups and surface properties of m-HA on drug delivery efficiency, ibuprofen was used as a model drug. In vitro drug delivery experimental results indicated that drug loading and release efficiency relied on functional groups, surface area, and porosity of m-HA. The percentage loading of ibuprofen was good for samples containing free –COOH groups and high surface area. A drug loading of 22 mg g−1 has been found for malonic acid modified HA (ma-HA) having high surface area, pore volume, whereas a poor loading of 2.03 mg g−1 has been observed for stearic acid modified HA (st-HA) sample having low surface area and pore volume. A sustained drug release profile showed that 61% drug had been released from malonic acid modified HA (ma-HA) in 24 hours. A 100% drug release was observed for st-HA in 8 hours. Succinic acid modified HA and adipic acid modified HA exhibited intermediate drug release profiles. The drug release behavior of m-HA followed Fick's laws of diffusion. more...
- Published
- 2016
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30. Biological behavior of bioactive glasses and their composites
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Aqif Anwar Chaudhry, Abdul Samad Khan, Nawshad Muhammad, Ihtesham Ur Rehman, Saba Zahid, Ather Farooq Khan, Arshad Jamal, and Asma Tufail Shah
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Angiogenesis ,Cell growth ,General Chemical Engineering ,Cellular differentiation ,0206 medical engineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Phosphate ,020601 biomedical engineering ,chemistry.chemical_compound ,Adsorption ,chemistry ,Composite material ,Solubility ,0210 nano-technology ,Cytotoxicity ,Protein adsorption - Abstract
Bioactive glasses (BGs) as third generation biomaterials have the ability to form an interfacial bonding more rapidly than other bioceramics between implant and host tissues in defect treatment. Therefore, BGs have shown great applications in the field of bone tissue engineering, dental materials, skin and other tissue regeneration. This review is based on inorganic and organic BG composites being used in bone tissue engineering and summarizes current developments in improving the biological behavior of BGs and their composites. A main focus was given to highlight the role of BGs and their composites in osteogenic differentiation and angiogenesis, followed by their cytotoxicity, protein adsorption ability and antibacterial properties. BGs were found to enhance the cell proliferation and cell attachment without any toxic effects with a significant increase in metabolic activity and possess osteogenic properties. Organic and inorganic dopants have been used to improve their cytocompatibility, osteoconductivity and promote stem cell differentiation towards the osteogenic lineage. BGs have also been used as graft materials because of their significant role in angiogenesis, as they stimulate relevant cells (i.e. fibroblasts, osteoblasts and endothelial cells) to release angiogenic growth factors. They show good protein adsorption because they act as templates for the adsorption of proteins which in turn depends upon surface properties. Antibacterial effects were also observed in BGs as a result of the high aqueous pH value in body fluids due to the presence of alkaline ions. There has been significant research work performed on silica-based bioactive glasses but not much literature can be found on phosphate- and borate-based bioactive glasses, which have good solubility and degradation, respectively. more...
- Published
- 2016
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31. Study of dielectric relaxations in co-precipitated Sr–Fe(Cr) nanoferrites
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Muhammad Anis-ur-Rehman, Fatima-tuz-Zahra, Seemab Kanwal, Anila Asif, Saba Zahid, Zeenat Khan, and Anam Noor Hussain
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Thermogravimetric analysis ,Materials science ,Analytical chemistry ,chemistry.chemical_element ,Dielectric ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Chromium ,Differential scanning calorimetry ,chemistry ,Electrical resistivity and conductivity ,Thermal stability ,Dielectric loss ,Electrical and Electronic Engineering ,Thermal analysis - Abstract
Chromium (Cr) doped strontium hexaferrites with nominal composition SrFe12−xCrxO19 (x = 0.0, 0.1, 0.2, 0.3) were prepared using co-precipitation method. Thermal analysis of the samples was carried out using thermogravimetric analysis and differential scanning calorimetry to study the thermal stability as well as the transitions within the samples with variation in temperature. Structural analysis of the samples was carried out using X-ray diffraction (XRD). XRD revealed that all the samples possess hexagonal structure with space group P63/mmc. AC electrical properties including dielectric constant (έ), dielectric loss tangent (tan δ) and ac electrical conductivity (σ ac ) were studied as a function of frequency (1 kHz–3 MHz) at temperatures 100–700 °C. The dielectric losses tend to decrease with increasing Cr content. AC conductivity could be very well explained by Jonscher power law. These materials have applications in high frequency devices with reduced energy losses. more...
- Published
- 2015
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32. Identification of anti-cancer potential of doxazocin: Loading into chitosan based biodegradable hydrogels for on-site delivery to treat cervical cancer
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Lubna Shahzadi, Saba Zahid, Samreen Ahtzaz, Aqif Anwar Chaudhry, Arshad Jamal, Muhammad Yar, and Ihtesham Ur Rehman
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Materials science ,Uterine Cervical Neoplasms ,Bioengineering ,Nanotechnology ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Polyvinyl alcohol ,Biomaterials ,Chitosan ,chemistry.chemical_compound ,In vivo ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,MTT assay ,Viability assay ,Fourier transform infrared spectroscopy ,Cell Cycle ,Doxazosin ,technology, industry, and agriculture ,G1 Phase ,Hydrogels ,021001 nanoscience & nanotechnology ,Flow Cytometry ,0104 chemical sciences ,Drug Liberation ,chemistry ,Mechanics of Materials ,Polyvinyl Alcohol ,Self-healing hydrogels ,Microscopy, Electron, Scanning ,Female ,Swelling ,medicine.symptom ,0210 nano-technology ,Nuclear chemistry - Abstract
In this study, an effective, biocompatible and biodegradable co-polymer comprising of chitosan (CS) and polyvinyl alcohol (PVA) hydrogels, chemically crosslinked and impregnated with doxazocin, is reported. The chemical structural properties of the hydrogels were evaluated by Fourier Transform Infrared spectroscopy (FTIR) and physical properties were analysed by scanning electron microscopy (SEM). The swelling behaviour is an important parameter for drug release mechanism and was investigated to find out the solution absorption capacity of the synthesized hydrogels. MTT assay revealed that doxazocin loaded hydrogels significantly hindered the cell viability. Flow cytometry analysis was performed to analyse the effect of 8CLH and 4CLH on regulation of cell cycle. Moreover, in vivo anti-cancer potential of synthesized hydrogels was assessed by CAM Assay. Results displayed that 8CLH with 1 mg/ml of doxazocin had prominently decreased the angiogenesis and significantly increased the number of cells in G1 phase of cell cycle. These results declared that 8CLH will be a good addition among hydrogels used for treatment of cancer by onsite delivery of drug. more...
- Published
- 2017
33. Sol-gel derived fluoridated and non-fluoridated bioactive glass ceramics-based dental adhesives: Compositional effect on re-mineralization around orthodontic brackets
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Saba Zahid, Asma Tufail Shah, Faisal Manzoor, Saad Asad, Abdul Samad Khan, and Hira Firzok
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Materials science ,Metallurgy ,Mineralization (soil science) ,Dental Adhesives ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Orthodontic brackets ,law ,visual_art ,Bioactive glass ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Ceramic ,Sol-gel - Published
- 2019
- Full Text
- View/download PDF
34. Influence of processing parameters and solid concentration on microstructural properties of gel-casted porous hydroxyapatite
- Author
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Aqif Anwar Chaudhry, Ihtesham Ur Rehman, Anila Asif, Rabia Nazir, Nafisa Ashraf, Saba Zahid, Tehseen Riaz, Anis Ur-Rehman, and Ramla Shahid
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Materials science ,food.ingredient ,Biocompatibility ,Scanning electron microscope ,Mechanical Engineering ,Biocompatible material ,Gelatin ,food ,Mechanics of Materials ,Interconnected porosity ,General Materials Science ,Composite material ,Fourier transform infrared spectroscopy ,Porosity ,Chemical composition - Abstract
Porous hydroxyapatite (HA) scaffolds with interconnected porosity have been successfully fabricated by using food grade gelatin as a gelling agent. Phase stability, chemical composition and topographical features of HA scaffolds were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy and scanning electron microscopy respectively. XRD study revealed that additives used in the gel-casting process did not influence the phase composition of the investigated materials. The porosity of sintered scaffolds was assessed by the liquid displacement method and found to be 55–76 %. The pores were tailored to spherical shape and size in the range 300–400 nm, feature of utmost interest to clinicians for cell attachment, proliferation and development of soft tissues. Biocompatibility of HA scaffolds was evaluated via hemolysis studies. The results of hemolysis proved the highly biocompatible behavior of the synthesized HA scaffolds. more...
- Published
- 2013
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35. Triethyl orthoformate covalently cross-linked chitosan-(poly vinyl) alcohol based biodegradable scaffolds with heparin-binding ability for promoting neovascularisation
- Author
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Sheila MacNeil, Aqif Anwar Chaudhry, Muhammad Yar, Lubna Shahzadi, Ihtesham Ur Rehman, Arshad Jamal, Saba Zahid, Muhammad Tariq, and Saadat Anwar Siddiqi
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Vinyl alcohol ,Materials science ,Formates ,Biomedical Engineering ,Neovascularization, Physiologic ,Chick Embryo ,02 engineering and technology ,macromolecular substances ,010402 general chemistry ,01 natural sciences ,Polyvinyl alcohol ,Chorioallantoic Membrane ,Biomaterials ,Chitosan ,chemistry.chemical_compound ,Absorbable Implants ,Materials Testing ,Polymer chemistry ,medicine ,Animals ,Tissue Engineering ,Tissue Scaffolds ,Heparin ,technology, industry, and agriculture ,Hydrogels ,Equipment Design ,021001 nanoscience & nanotechnology ,Triethyl orthoformate ,0104 chemical sciences ,Equipment Failure Analysis ,Cross-Linking Reagents ,chemistry ,Polyvinyl Alcohol ,Self-healing hydrogels ,Blood Vessels ,Adsorption ,Swelling ,medicine.symptom ,0210 nano-technology ,Wound healing ,Protein Binding ,medicine.drug - Abstract
There is a need to develop pro-angiogenic biomaterials to promote wound healing and to assist in regenerative medicine. To this end, various growth factors have been exploited which have the potential to promote angiogenesis. However, these are generally expensive and labile which limits their effectiveness. An alternative approach is to immobilize heparin onto biocompatible degradable hydrogels. The heparin in turn will then bind endogenous proangiogenic growth factors to induce formation of new blood vessels. In this study, we continue our development of hydrogels for wound healing purposes by exploring covalently cross-linking chitosan and polyvinyl alcohol hydrogels using triethyl orthoformate. Two concentrations of triethyl orthoformate (4 and 16%) were compared for their effects on the structure of hydrogels – their swelling, pore size, and rate of degradation and for their ability to support the growth of cells and for their heparin-binding capacity and their effects on angiogenesis in a chick chorioallantoic membrane assay. Hydrogels formed with 4 or 16% both triethyl orthoformate cross-linker were equally cyto-compatible. Hydrogels formed with 4% triethyl orthoformate absorbed slightly more water than those made with 16% triethyl orthoformate and broke down slightly faster than non-cross-linked hydrogels. When soaked in heparin the hydrogel formed with 16% triethyl orthoformate showed more blood vessel formation in the CAM assay than that formed with 4% triethyl orthoformate. more...
- Published
- 2016
36. Effect of calcium hydroxide on mechanical strength and biological properties of bioactive glass
- Author
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Ihtesham Ur Rehman, Farasat Iqbal, Kanwal Ilyas, Madeeha Batool, Saba Zahid, Saad Bin Qasim, Ayesha Javaid, Ather Farooq Khan, Asma Tufail Shah, Aqif Anwar Chaudhry, and Abdul Samad Khan
- Subjects
Thermogravimetric analysis ,Ceramics ,Materials science ,Surface Properties ,Biomedical Engineering ,chemistry.chemical_element ,Biocompatible Materials ,02 engineering and technology ,Calcium ,engineering.material ,010402 general chemistry ,01 natural sciences ,Wollastonite ,law.invention ,Biomaterials ,Calcium Hydroxide ,chemistry.chemical_compound ,Differential scanning calorimetry ,X-Ray Diffraction ,law ,Spectroscopy, Fourier Transform Infrared ,Fourier transform infrared spectroscopy ,Composite material ,Calcium hydroxide ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,Bioactive glass ,Knoop hardness test ,engineering ,Microscopy, Electron, Scanning ,Glass ,0210 nano-technology ,Nuclear chemistry - Abstract
In this manuscript for the first time calcium hydroxide (Ca(OH)2) has been used for preparation of bioactive glass (BG-2) by co-precipitation method and compared with glass prepared using calcium nitrate tetrahydrate Ca(NO3)2·4H2O (BG-1), which is a conventional source of calcium. The new source positively affected physical, biological and mechanical properties of BG-2. The glasses were characterized by Fourier transform infrared (FTIR), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA-DSC), BET surface area analysis and Knoop hardness. The results showed that BG-2 possessed relatively larger surface properties (100m(2)g(-1) surface area) as compared to BG-1 (78m(2)g(-1)), spherical morphology and crystalline phases (wollastonite and apatite) after sintering at lower than conventional temperature. These properties contribute critical role in both mechanical and biological properties of glasses. The Knoop hardness measurements revealed that BG-2 possessed much better hardness (0.43±0.06GPa at 680°C and 2.16±0.46GPa at 980°C) than BG-1 (0.24±0.01 at 680°C and 0.57±0.07GPA at 980°C) under same conditions. Alamar blue Assay and confocal microscopy revealed that BG-2 exhibited better attachment and proliferation of MG63 cells. Based on the improved biological properties of BG-2 as a consequent of novel calcium source selection, BG-2 is proposed as a bioactive ceramic for hard tissue repair and regeneration applications. more...
- Published
- 2016
37. Relationship between Academic Boredom, Learning Climate and Academic Motivation Among University Students.
- Author
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Khan, Saira, Sadia, Rayna, Hayat, Saba Zahid, and Tahir, Sonia
- Subjects
ACADEMIC motivation ,BOREDOM ,EXTRINSIC motivation ,INTRINSIC motivation ,COLLEGE students - Abstract
The present research aimed at exploring the relationship between academic motivation, learning climate (Autonomy supported) and academic boredom among university students. In addition to this it aimed at confirming the mediating role of learning climate in relationship between intrinsic motivation and academic boredom among students studying in Universities of Pakistan. For the present study data was collected from 399 university students. The age of the sample ranged from 17 to 35 years (M = 21.45, SD = 2.40). Reliability coefficients of all the variables ranged from .65-.89 (Class Related Boredom Scale = .89, Learning Climate Questionnaire =.88, Academic Motivation Scale = .82, Intrinsic Motivation = .81, Extrinsic Motivation = .81, and A Motivation =.65). Further correlational analysis indicated a negative relationship of classroom related boredom with learning climate and intrinsic motivation. However, class related boredom was found to have positive relationship with extrinsic and a motivation. Learning climate (autonomy supportive) showed positive relation with intrinsic motivation. Based upon literature, mediation analysis was carried out which confirmed the mediating role of learning climate (autonomy supportive) in relation between intrinsic motivation and academic boredom. In the light of existing literature, findings were discussed, and suggestions were given for future researches. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
- View/download PDF
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