Impact of Tillage, Plant Population and Mulches on Phenological Characters of Maize

Bakhtiar Gul,Khan Bahadar Marwat,M. Saeed,Haidar Ali 한국잡초학회 2011 한국잡초학회 별책(학술대회 초록집) Vol.31 No.2

In vivo evaluation of biodistribution and toxicity of pH-responsive strontium nanoparticles for gene deliveryIn vivo evaluation of biodistribution and toxicity of pH-responsive strontium nanoparticles for gene delivery

Bakhtiar Athirah,Neah Aik Seng,Ng Khuen Yen,Chowdhury Ezharul Hoque 한국약제학회 2022 Journal of Pharmaceutical Investigation Vol.52 No.1

Purpose Low efficacy of parenteral administration of naked therapeutic genes is associated with the presence of biological barriers including circulatory monocytes that clear and eliminate foreign materials via reticuloendothelial system. Chemically synthesized inorganic strontium nanoparticles (SNPs) present a way to improve the delivery of genetic content to the targeted tissues of mammary carcinoma while protecting the load from premature degradation. Methods Biodistribution profiles in the brain, liver, spleen, kidneys, lung, and mammary tumor of BALB/c mice were investigated at 1, 2 and 4 h following intravenous administration of fluorescent siRNA-loaded SNPs. Following SNPs-mediated in vivo delivery of p53 gene and MAPK siRNA, the effects of exogenous p53 expression and silencing of endogenous MAPK were analyzed via tumor size measurement over 14 days. Results SNPs mainly accumulate in the liver and kidney with notable deposition in the brain, lung, spleen, and tumor tissues. However, higher salt concentrations hindered the optimal localization of SNPs in tumor tissues. Despite lower residual accumulation in tumor tissues, mice treated with SNPs carrying either p53 gene or MAPK siRNA demonstrated slower tumor growth than those treated with the naked gene or siRNA. Unlike p53 gene, higher siRNA concentration resulted in lower regression activity of the carcinoma tissues, which might be due to unexpected off-target effects. Conclusion The effective role of SNPs in overcoming biological barriers in vivo and supporting gene trafficking for substantial nucleic acid activities at the targeted tissues provides an opportunity for future novel therapeutic strategies for breast cancer.

Distributed Matching Algorithms for Spectrum Access: A Comparative Study and Further Enhancements

( Bakhtiar Ali ),( Nida Zamir ),( Soon Xin Ng ),( Muhammad Fasih Uddin Butt ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.4

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

Engineering of highly mismatched alloy with semiconductor and semi-metallic substituent's for photovoltaic applications

Bakhtiar Ul Haq,R. Ahmed,Mazmira Mohamad,A. Shaari,이주열,S. AlFaify,Mohammed Benali Kanoun,Souraya Goumri-Said 한국물리학회 2017 Current Applied Physics Vol.17 No.2

Highly mismatched alloys (HMAs) are getting a substantial interest of researchers because of holding competence of rapid change in physical properties with minor compositional change and consequently showing their potential for solar energy and photovoltaic applications. In the present density functional theory based work, we design HMAs from the extremely dissimilar GaP (semiconductor) and GaBi (semimetal). The alloying of the two compounds with unmatched electronic characteristics has triggered a rapid reduction in the energy gap of GaPBi. The energy gap is reduced by 39.3 meV for every 1% increase in Bi composition. The semiconductor behavior of GaPBi based HMAs is found to be transformed to semimetallic for replacing 64.6% of P atoms by Bi. Unlike the conventional alloys, the variation in the electronic energy gap of GaP1-xBix shows deviation from the Vegard's formalism. Where the optical properties are strongly influenced with the narrowing energy gap of GaPBi. For the Bi-rich GaPBi, the notable red shift is observed in optical dielectric function and absorption spectra. Moreover, the larger atomic size of Bi has enhanced the lattice parameters of Bi-rich GaPBi. The GaPBi based HMAs with tunable energy gap in the span of 2.51 eVe0 eV and the interesting optical properties highlight them prospective materials for optoelectronic applications.

Active targeting via ligand-anchored pH-responsive strontium nanoparticles for efficient nucleic acid delivery into breast cancer cellsActive targeting via ligand-anchored pH-responsive strontium nanoparticles for efficient nucleic acid delivery into bre

Bakhtiar Athirah,Liew Qing Xin,Ng Khuen Yen,Chowdhury Ezharul Hoque 한국약제학회 2022 Journal of Pharmaceutical Investigation Vol.52 No.2

Purpose Gene therapy is a promising and novel therapeutic strategy for many mutated gene-associated diseases, including breast cancer. However, it poses significant biological drawbacks such as rapid clearance from the circulatory system and low cellular uptake of the exogenously delivered functional nucleic acids. The development of efficient and biocompatible carriers for genetic materials has been extensively explored in the literature, and the functionalization of nanoparticles (NPs) with cancer cell-recognizing ligands has become an attractive approach to promote tumor targetability and efficient cellular internalization via endocytosis. Methods This study introduced self-assembling targeting ligands, including transferrin and fibronectin with the ability to electrostatically interact with strontium nanoparticles (SNPs), and then analyzed their influence on size and zeta potential of the resultant hybrid SNPs, cellular uptake and expression efficiency of transgene-loaded hybrid NPs. Results Smaller ligand-coated SNPs (LCSNPs) remarkably increased gene transfection activity in both MCF-7 and 4T1 cells as well as nucleic acid localization into tumor tissues with improved tumor regression activity in a 4T1-tumor xenograft mouse model. Conclusion LCSNPs-mediated delivery of p53 gene and MAPK siRNA provided a proof-of-concept for the functionalized nanocarrier formulation in order to inhibit breast cancer cell growth.

‘Close Your Book and Open Your Facebook’ : A Case for Extending Classroom Collaborative Activities Online

Bakhtiar Naghdipour 아시아영어교육학회 2017 The Journal of Asia TEFL Vol.14 No.1

This study investigated EFL language teachers’ and learners’ evaluation of classroom-based pair and group work activities during an intensive English language program and it sought their opinions on the potential of Facebook to extend such collaborative activities online. Data were collected from 26 teachers and 178 pre-intermediate students using surveys and semi-structured interviews at an international university in Cyprus. The data analysis revealed that despite acknowledging the benefits involved in using pair and group work tasks in their classes, more than half of the participants reported that students developed the feelings of boredom and demotivation toward participating in classroombased collaborative activities, mostly due to their overuse, poor design, and failure to cater to students’ learning needs and beliefs and their educational and cultural backgrounds. The results also indicated that, under some conditions, Facebook could function as a learning environment to revamp students’ interest and facilitate their engagement in collaborative language learning activities. Both students and teachers suggested specific ideas with respect to the informal as well as formal integration of Facebook into language learning classes.

The Impact of L1 Reading Directionality Mode on L2 Reading Fluency

Bakhtiar Naghdipour 아시아영어교육학회 2015 The Journal of Asia TEFL Vol.12 No.1

Cross-orthography research has thus far focused on the effect of learners’ first language (L1) reading ability in alphabetic or nonalphabetic languages on their second language (L2) reading performance, paying scant attention to the different aspects of L2 reading performance in learners of two alphabetic languages that have different writing systems or reading directionality modes. This study, however, examines the impact of L1 reading directionality on English reading fluency–represented here by a combination of reading rate, reading accuracy, and reading comprehension–in Turkish and Arab learners of English. Different reading texts from both first and second languages were employed to compare undergraduate intermediate students’ (n = 40) performance on different components of reading fluency. Students were also interviewed upon the completion of the tasks in order to obtain in-depth insights into the way they approached reading and the challenges they encountered while reading in each language. Analysis of the data indicated that in spite of significant differences in some areas, the learners’ L1 reading directionality mode did not have a significant effect on all aspects of their reading fluency in English. However, the observed differences between the mean scores of reading fluency components could have pedagogical implications for classroom practice.

A Study on Water Balance in Stationary Load Proton Exchange Membrane(PEM) Fuel Cell Power Generator

Agung Bakhtiar(아궁 박타아르),Oh,Hoo-Kyu(오후규),Yoon,Jung-In(윤정인),Kim,Young-Bok(김영복),Choi,Kwang-Hwan(최광환) 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.4

일반적으로 PEM 연료전지에서는 수분 균형이 시스템의 효율에 결정적으로 영향을 미치기 때문에, 이에 대한 균형(balance)을 잡는 것이 매우 중요하다. 특히, 촉매 층에서 물이 넘치는 익수현상(flooding)이나 건조현상(drying)이 발생하게 되면 연료전지의 효율이 급격하게 저하하므로, 항상 수분의 균형이 잡히도록 시스템을 제어하는 것이 일반적이다. 이 때, 수분의 익수현상이나 건조현상은 PEM 연료전지의 용량과 주위의 환경, 즉 온도와 습도에 많은 영향을 받게 된다. 금번 논문에서는 가정용 규모인 3㎾급에서 10㎾급까지의 PEM 연료전지를 설치하였을 때, 주위의 환경(온도와 습도)이 수분 이동에 어떠한 영향을 미치는 지를 시간에 따라서 시뮬레이션(simulation)한 결과를 보여주고 있다. 결과에서 유입공기의 온도가 50℃ 이하일 경우, 고정부하가 5㎾급 이하이면 대부분이 건조현상이 발생하였으나, 고정부하가 6㎾급 이상이 되면 익수현상이 운전시간이 20분 이내에서 발생하였다. 또한 고정부하를 최고 10㎾급까지 올린 경우, 유입공기의 온도가 50℃까지는 익수현상이 발생하였으나 60℃ 이상인 경우에는 거의 건조현상이 발생함을 알 수 있었다.

Engineering of highly mismatched alloy with semiconductor and semi-metallic substituent's for photovoltaic applications

Haq, Bakhtiar Ul,Ahmed, R.,Mohamad, Mazmira,Shaari, A.,Rhee, JooYull,AlFaify, S.,Kanoun, Mohammed Benali,Goumri-Said, Souraya ELSEVIER 2017 Current Applied Physics Vol.17 No.2

<P>Highly mismatched alloys (HMAs) are getting a substantial interest of researchers because of holding competence of rapid change in physical properties with minor compositional change and consequently showing their potential for solar energy and photovoltaic applications. In the present density functional theory based work, we design HMAs from the extremely dissimilar GaP (semiconductor) and GaBi (semi metal). The alloying of the two compounds with unmatched electronic characteristics has triggered a rapid reduction in the energy gap of GaPBi. The energy gap is reduced by 39.3 meV for every 1% increase in Bi composition. The semiconductor behavior of GaPBi based HMAs is found to be transformed to semi metallic for replacing 64.6% of P atoms by Bi. Unlike the conventional alloys, the variation in the electronic energy gap of GaP1-xBix shows deviation from the Vegard's formalism. Where the optical properties are strongly influenced with the narrowing energy gap of GaPBi. For the Bi-rich GaPBi, the notable red shift is observed in optical dielectric function and absorption spectra. Moreover, the larger atomic size of Bi has enhanced the lattice parameters of Bi-rich GaPBi. The GaPBi based HMAs with tunable energy gap in the span of 2.51 eV-0 eV and the interesting optical properties highlight them prospective materials for optoelectronic applications. (C) 2016 Elsevier B.V. All rights reserved.</P>

Study on the sampling time for the model based adaptive water management on PEM fuel cell

Agung Bakhtiar,Jin-Kwang You(유진광),Kwang-Hwan Choi(최광환) 한국태양에너지학회 2014 한국태양에너지학회 학술대회논문집 Vol.2014 No.3