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Now showing items 1 - 16 of 93

  • Nanosilver Mitigates Biofilm Formation via FapC Amyloidosis Inhibition

    Huma, Zil-e   Javed, Ibrahim   Zhang, Zhenzhen   Bilal, Hajira   Sun, Yunxiang   Hussain, Syed Zajif   Davis, Thomas P.   Otzen, Daniel E.   Landersdorfer, Cornelia B.   Ding, Feng   Hussain, Irshad   Ke, Pu Chun  

    Multidrug resistance of bacteria is a major challenge due to the wide-spread use of antibiotics. While a range of strategies have been developed in recent years, suppression of bacterial activity and virulence via their network of extracellular amyloid has rarely been explored, especially with nanomaterials. Here, silver nanoparticles and nanoclusters (AgNPs and AgNCs) capped with cationic branched polyethylenimine polymer are synthesized, and their antimicrobial potentials are determined at concentrations safe to mammalian cells. Compared with the ultrasmall AgNCs, AgNPs entail stronger binding to suppress the fibrillization of FapC, a major protein constituent of the extracellular amyloid matrix of Pseudomonas aeruginosa. Both types of nanoparticles exhibit concentration-dependent antibiofilm and antimicrobial properties against P. aeruginosa. At concentrations of 1 x 10(-6) m or below, both the bactericidal activity of AgNCs and the antibiofilm capacity of AgNPs are associated with their structure-mediated bio-nano interactions but not ion release. For AgNPs, specifically, their antibiofilm potency correlates with their capacity of FapC fibrillization inhibition, but not with their bactericidal activity. This study demonstrates the antimicrobial potential of safe nanotechnology through the novel route of amyloidosis inhibition.
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  • Dose response of black American mink to Aleutian mink disease virus

    Farid, A. Hossain   Hussain, Irshad  

    Introduction Aleutian mink disease virus (AMDV) causes a serious health problem for mink globally. The disease has no cure nor an effective vaccine and selection for tolerance using antibody titer is adopted by many mink farmers. The objective of this study was to investigate the effects of various doses of a local AMDV isolate on the response of black American mink to infection with AMDV. Methods Eight black American mink were each inoculated intranasally with 0.5 mL of eight serial 10-fold dilutions (10(0) to 10(-7)) of a 10% spleen homogenate containing a local AMDV isolate. Blood samples were collected on days 0, 20, 35, 56, 84, 140, and 196 postinoculation (dpi). Anti-AMDV antibodies and viral DNA were tested by counter-immunoelectrophoresis (CIEP) and PCR, respectively. Animals that were PCR or CIEP positive at 196 dpi (n =3D 41) were killed at 218 dpi, and samples of blood and seven organs were tested by CIEP and PCR. Results Antibody production persisted in all seroconverted mink until the termination of the experiment, whereas 71.1% of the mink showed short-lived viremia. Significant associations were observed between inoculum dose and the incidence of viremia until 84 dpi which disappeared thereafter, whereas associations between inoculum dose and the incidence of seropositive mink were significant on all sampling occasions. Antibody titer at 218 dpi significantly decreased with decreasing inoculum dose. AMDV DNA was detected in the bone marrow, lymph nodes, and spleen samples of almost all mink inoculated at every dose but was not detected in other organs of some mink. Conclusions CIEP is more accurate than PCR for detecting AMDV infection in mink. Using antibody titer in naturally infected mink may not be accurate for the identification of tolerant mink.
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  • Social Media as a Learning Technology for University Students

    Hussain, Irshad   Cakir, Ozlem   Candeger, Ummugulsum  

    This paper demonstrates the role of social media as a learning technology for university students and highlights their problems associated with its use. The population of the study consisted of Masters' and Bachelor Studies students studying in their final semesters in the departments of Social Sciences at The Islamia University of Bahawalpur, Pakistan; and using social media for more than three years. The data was collected from 450 students taken convenient cum purposively according to the nature of study. A questionnaire on five point rating (Likert) scale was developed and used as a research tool. The tool was finalized after its pilot testing and it was administered to elicit opinions of the respondents. The study demonstrated that social media plays a significant role as a learning technology. Its careful use promotes opportunities of virtual interactions among university students, instant access to multiple, latest, reliable and students' preferred sources of learning. It facilitates in nurturing critical thinking, problem solving approach and argumentation among university students by illustrating application of theories and/ or techniques through examples, visuals and illustrations and videos, and assists them with mastery learning and futuristic approach through task oriented activities.
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  • Combatting antibiotic-resistant bacteria using nanomaterials

    Gupta, Akash   Mumtaz, Shazia   Li, Cheng-Hsuan   Hussain, Irshad   Rotello, Vincent M.  

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  • Seasonal variation's effect on antidiabetic activity of silver nanoparticles

    Tahir, Humna   Rahman, Jameel   Ashraf, Muhammad   Anjum, Shazia   Hussain, Irshad   Warsi, Muhammad Farooq  

    The present work develops an eco-friendly protocol that was adopted to synthesize silver nanoparticles (AgNPs) from the aqueous extract of Corchorus depressus collected in three different seasons. Visually, the formation of AgNPs was confirmed by the change in the color of extracts to reddish brown and the AgNPs were further characterized by ultraviolet-visible studies of the absorption band at 435-450 nm that is due to surface plasmon resonance of AgNPs. The functional groups that behave as a reducing agent and those that act as a capping agent were determined by the FTIR. The particle size was determined by scanning electron microscopy and the amount of capping agents (organic contents at the surface of AgNPs) was estimated by thermogravimetric analysis. AgNPs showed a remarkable inhibitory activity against a-glucosidase compared to their respective aqueous extracts. Extraction of plant material collected in the month of January and their AgNP formation showed the smallest particle size of 4 +/- 2 nm. Moreover, an augmented remarkable inhibitory activity against the carbohydrate-digesting enzyme a-glucosidase with IC50 of 2.48 +/- 0.56 mu g/ml was also observed compared to other extracts.
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  • Molecular basis of Cd+2 stress response in Candida tropicalis

    Khan, Zaman   Rehman, Abdul   Nisar, Muhammad Atif   Zafar, Saima   Hussain, Syed Zajif   Zerr, Inga   Hussain, Irshad   Waseem, Muhammad   Arif, Muhammad  

    This study examines the bioremediation potential and cadmium-induced cellular response on a molecular level in Candida tropicalis 3Aer. Spectroscopic analysis clearly illustrated the involvement of yeast cell wall components in biosorption. Cadmium bioaccumulation was confirmed by TEM, SEM, and EDX examination. TEM images revealed extracellular as well as cytoplasmic and vacuolar cadmium nanoparticle formation, further validated by presence of ycf1 gene and increased biosynthesis of GSH under cadmium stress. Fourteen proteins exhibited differential expression and during cellular redox homeostasis are found to involve in nitrogen metabolism, nucleotide biosynthesis, and carbohydrate catabolism. Interestingly, C. tropicalis 3Aer is equipped with nitrile hydratase enzyme, rarely been reported in yeast. It has the potential to remove nitriles from the environment. The Cd+2 toxicity not only caused growth stasis but also upregulated the cysteine biosynthesis, protein folding and cytoplasmic detoxification response elements. The present study suggests that C. tropicalis 3Aer is a potential candidate for bioremediating environmental pollution by Cd+2.
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  • Optical Investigation of Sm3+ Doped in Phosphate Glass

    Hussain, Saddam   Amjad, Raja J.   Tanveer, Muhammad   Nadeem, Muhammad   Mahmood, Hasan   Sattar, Abdul   Iqbal, Azmat   Hussain, Irshad   Amjad, Z.   Hussain, Syed Zajif   Siddique, S. A.   Reza Dousti, M.  

    Samarium doped zinc-magnesium-phosphate glasses having composition (60 - x)P2O5-10MgO-30ZnO-xSm(2)O(3) where x =3D 0.1, 0.3, 0.6, 1.0 mol % were prepared by melt quenching technique. Archimedes method was used to measure their densitieswhich are lying in the range 2.65-2.91 g/cm(3). On the basis of the increasing trend in the density while increasing the content of Sm2O3 it can be concluded that the bridging oxygen is converted to non-bridging oxygen The UV-Vis absorption spectroscopy was carried on in the wavelength range 310-900 nm where the absorption spectra consist of six absorption peaks corresponding to the transitions from the ground state H-6(5/2) to various excited energy levels. The optical band gaps are calculated to be 3.93-4.41 eV, 3.31-3.73 eV and 0.27-0.29 eV for direct band gap, indirect band gap and Urbach energy, respectively. The physical parameters like oxygen packing density, refractive index, molar refractivity, metallization, and electronic polarizability are also studied. The Differential Scanning Calorimetry (DSC) technique is used to evaluate the thermal stability.
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  • Layered microporous polymers by solvent knitting method

    Wang, Shaolei   Zhang, Chengxin   Shu, Yu   Jiang, Shulan   Xia, Qi   Chen, Linjiang   Jin, Shangbin   Hussain, Irshad   Cooper, Andrew I.   Tan, Bien  

    Two-dimensional (2D) nanomaterials, especially 2D organic nanomaterials with unprecedentedly diverse and controlled structure, have attracted decent scientific interest. Among the preparation strategies, the top-down approach is one of the considered low-cost and scalable strategies to obtain 2D organic nanomaterials. However, some factors of their layered counterparts limited the development and potential applications of 2D organic nanomaterials, such as type, stability, and strict synthetic conditions of layered counterparts. We report a class of layered solvent knitting hyper-cross-linked microporous polymers (SHCPs) prepared by improving Friedel-Crafts reaction and using dichloroalkane as an economical solvent, stable electrophilic reagent, and external cross-linker at low temperature, which could be used as layered counterparts to obtain previously unknown 2D SHCP nanosheets bymethod of ultrasonic-assisted solvent exfoliation. This efficient and low-cost strategy can produce previously unreported microporous organic polymers with layered structure and high surface area and gas storage capacity. Thepore structure and surface area of these polymers can be controlled by tuning the chain length of the solvent, the molar ratio of AlCl3, and the size of monomers. Furthermore, we successfully obtain an unprecedentedly high-surface area HCP material (3002 m(2) g(-1)), which shows decent gas storage capacity (4.82 mmol g(-1) at 273 K and 1.00 bar for CO2; 12.40 mmol g(-1) at 77.3 K and 1.13 bar for H-2). This finding provides an opportunity for breaking the constraint of former knitting methods and opening up avenues for the design and synthesis of previously unknown layered HCP materials.
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  • Catalysis by multifunctional polyelectrolyte capsules

    Hussain, Syed Zajif   Zyuzin, Mikhail V.   Hussain, Irshad   Parak, Wolfgang J.   Carregal-Romero, Susana  

    Gold nanoparticles and nanocomposites have high catalytic performance for several chemical reactions. Here we present gold and iron oxide nanoparticle modified polymer capsules as porous and multifunctional platforms for catalysis. Layer-by-layer polyelectrolyte microcapsules were formed on calcium carbonate template cores loaded with gold nanoparticles, allowing for high gold loading of the capsules. Magnetic nanoparticles were incorporated in the polymeric shells of the capsules, allowing for magnetic separation. The influence on the catalytic behaviour of gold was studied in terms of the nanoparticle size, the presence of a polymeric shell, and the presence of the magnetic nanoparticles in the shell, by using the model electron transfer reaction between hexacyanoferrate(III) and borohydride.
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  • Tracking a Decentralized Linear Trajectory in an Intermittent Observation Environment

    Ullah, Wasi   Hussain, Irshad   Shehzadi, Iram   Rahman, Zahid   Uthansakul, Peerapong  

    Faults and failures are familiar case studies in centralized and decentralized tracking systems. The processing of sensor data becomes more severe in the presence of faults/failures and/or noise. Effective schemes have been presented for decentralized systems, in the presence of faults only. In some practical scenarios of systems, there are certain interruptions in addition to these faults. These interruptions may occur in the form of noise. However it is expected that the decision about the sensor data is difficult in the presence of noise. This is because the noise adversely affects the communication amongst sensors and the processing unit. More complexity is expected when there are faults and noise simultaneously. To deal with this problem, in addition to existing fault detection and isolation schemes, the Kalman filter is employed. Here, a generic discussion is provided, which is equally applicable to other situations. This work addresses various faults in the presence of noise for decentralized tracking systems. Local single faults and multiple faults in the presence of noise are the core issues addressed in this paper. The proposed work is comprised of a general scenario for a decentralized tracking system followed by a case study of a target tracking scenario with and without noise. The presented schemes are also tested for different types of faults. The proposed work presents effective tracking in the presence of noise and faults. The results obtained demonstrate the acceptable performance of the scheme of this work.
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  • A Study to Evaluate the Social Media Trends among University Students

    Hussain, Irshad  

    The study was conducted to a). examine the trend of using social media among university students, b). evaluate reasons behind using social media, and c). identify the problems of university students in using social media. The population of the study consisted on all 4th semesters' students of Faculty of Education of the Islamia University of Bahawalpur, Pakistan. The sample size comprised of 600 students taken through convenient sampling technique. A questionnaire was developed for data collection. The research tool was finalized after its pilot testing. The study revealed that majority (90%) of the students was inclined to use face-book. They used social media for exchanging academic activities and developing social networks throughout the world. They used such media for sharing their learning experiences with their colleagues and international community. It was obvious from the study that social media played a crucial role in promoting collaboration and linkage to develop Virtual Community across the world. The respondents also faced some problems in using social media. They faced problems of bandwidth of internet and electricity break down/load shedding. (C) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of The Association Science Education and Technology
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  • Analysis of procrastination among university students

    Hussain, Irshad   Sultan, Sarwat  

    The present study focused on analyzing the factors of procrastination and its effects on learning of university students. It was conducted on 500 students and 40 teachers of the Islamia University of Bahawalpur, Pakistan through survey approach. The study concluded that procrastination effects on the academic performance of students in terms of classroom learning and participation in activities, submission of their assignments, preparing for the examinations and achievement. Likewise, the work load of assignments' and improper time management by the students caused procrastination. (C) 2010 Elsevier Ltd. All rights reserved.
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  • Cationic Silver Nanoclusters as Potent Antimicrobials against Multidrug-Resistant Bacteria

    Huma, Zil-e   Gupta, Akash   Javed, Ibrahim   Das, Riddha   Hussain, Syed Zajif   Mumtaz, Shazia   Hussain, Irshad   Rotello, Vincent M.  

    Bacterial multidrug resistance (MDR) is a serious healthcare issue caused by the long-term subtherapeutic clinical treatment of infectious diseases. Nanoscale engineering of metal nanoparticles has great potential to address this issue by tuning the nano-bio interface to target bacteria. Herein, we report the use of branched polyethylenimine-functionalized silver nanoclusters (bPEI-Ag NCs) to selectively kill MDR pathogenic bacteria by combining the antimicrobial activity of silver with the selective toxicity of bPEI toward bacteria. The minimum inhibitory concentration of bPEI-Ag NCs was determined against 12 uropathogenic MDR strains and found to be 10- to 15-fold lower than that of PEI and 2- to 3-fold lower than that of AgNO3 alone. Cell viability and hemolysis assays demonstrated the biocompatibility of bPEI-Ag NCs with human fibroblasts and red blood cells, with selective toxicity against MDR bacteria.
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  • Cationic Silver Nanoclusters as Potent Antimicrobials against Multidrug-Resistant Bacteria

    Huma, Zil-e   Gupta, Akash   Javed, Ibrahim   Das, Riddha   Hussain, Syed Zajif   Mumtaz, Shazia   Hussain, Irshad   Rotello, Vincent M.  

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  • Cell to rodent: toxicological profiling of folate grafted thiomer enveloped nanoliposomes.

    Sohail, Muhammad Farhan   Sarwar, Hafiz Shoaib   Javed, Ibrahim   Nadhman, Akhtar   Hussain, Syed Zajif   Saeed, Hamid   Raza, Abida   Irfan Bukhari, Nadeem   Hussain, Irshad   Shahnaz, Gul  

    Polymeric nanomaterials, hybridized with lipid components, e.g. phosphocholine or fatty acids, are currently being explored for efficient nano-platforms for hydrophobic drugs. However, their toxicology and toxicokinetics need to be established before enabling their clinical potential. The aim of this study was to investigate the toxicological profile of thiomer enveloped hybrid nanoliposomes (ENLs) and bare nanoliposomes (NLs), loaded with docetaxel (DTX) hydrophobic drug, biocompatible nano-carriers for therapeutic cargo. The in vitro toxicity of hybrid ENLs and NLs was evaluated towards the HCT-116 colon cancer cell line. Biocompatibility was explored against macrophages and acute oral toxicity was examined in mice for 14 days. The anticancer IC50 for ENLs was 0.148 mug ml-1 compared with 2.38 mug ml-1 for pure docetaxel (DTX). The human macrophage viability remained above 65% and demonstrated a high level of biocompatibility and safety of ENLs. In vivo acute oral toxicity showed slight changes in serum biochemistry and haematology but no significant toxicities were observed referring to the safety of DTX loaded hybrid ENLs. On histological examination, no lesions were determined on the liver, heart and kidney. These studies showed that hybrid ENLs can serve as a safe and biocompatible platform for oral delivery of hydrophobic drugs.=20
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  • Photoreductive synthesis of water-soluble fluorescent metal nanoclusters RID C-5663-2009

    Zhang, Hui   Huang, Xin   Li, Luo   Zhang, Gaowen   Hussain, Irshad   Li, Zhen   Tan, Bien  

    Water-soluble fluorescent copper, silver and gold nanoclusters with quantum yields of 2.2, 6.8 and 5.3%, respectively, are prepared by a robust photoreduction of their inorganic precursors in the presence of poly (methacrylic acid) functionalized with pentaerythritol tetrakis 3-mercaptopropionate.
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