Cadmium-Induced Changes in Antioxidant Enzyme Activities in Rice(Oryza sativa L. cv. Dongjin)

Ali, Mohammad Babar,Chun, Hyun Sik,Kim, Byung Ki,Lee, Chin Bum 한국식물학회 2002 Journal of Plant Biology Vol.45 No.3

We studied how the relationship between cadmium (Cd) toxicity and oxidative stress influenced the growth, photo-synthetic efficiency, lipid peroxidation, and activity of ntioxidative enzymes in the roots and leaves of rice (Oryza sativa L Dongjin). Plants were exposed to Cd for 21 d. Both seedling growth and photosynthetic efficiency decreased gradually with increasing cadmium concentrations. Lipid peroxidation increased slowly in both roots and leaves, causing oxidative stress. However, each tissue type responded differently to Cd concentrations with regard to the induction/inhibition of antioxidative enzymes. The activity of superoxide dismutase (SOD) increased in both roots and leaves. Ascorbate peroxidase (APX) activity increased in leaves treated with up to 0.25 μM Cd, then decreased gradually at higher concentrations. In contrast, APX activity in roots increased and remained constant between 0.25 and 25 μM Cd. Enhanced peroxidase (POD) activity was recorded for treatments with up to 25 μM Cd, gradually decreasing at higher concentrations in the leaves but remaining unchanged in the roots. Catalase (CAT) activity increased in the roots, but decreased in the leaves, whereas the activity of glutathione reductase (GR) was enhanced in both roots and leaves, where it remained elevated at higher Cd concentrations. These results suggest that rice seedlings tend to cope with free radicals generated by Cd through coordinated, enhanced activities of the antioxidative enzymes involved in detoxification.

Response of Antioxidant Enzymes in Rice(Oryza sativa L. cv. Dongjin) under Mercury Stress

Ali, Mohammad Babar,Chun, Hyun Sik,Lee, Chin Bum 한국식물학회 2002 Journal of Plant Biology Vol.45 No.3

We studied the effects of different concentrations of mercury (0.0 to 100 μM) on growth and photosynthetic efficiency in rice plants treated for 21 d. In addition, we investigated how this metal affected the malondialdehyde (MDA) content as well as the activity of five antioxidant enzymes - superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), guaiacol peroxidase (POD), and catalase (CAT). Photosynthetic efficiency (F_v/F_m) and seedling growth decreased as the concentration of Hg was increased in the growth media. Plants also responded to Hg-induced oxidative stress by changing the levels of their antioxidative enzymes. Enhanced lipid peroxidation was observed in both leaves and roots that had been exposed to oxidative stress, with leaves showing higher enzymatic activity. Both SOD and APX activities increased in treatments with up to 50 μM Hg, then decreased at higher concentrations. In the leaves, both CAT and POD activities increased gradually, with CAT levels decreasing at higher concentrations. In the roots, however, CAT activity remained unchanged while that of POD increased a bit more than did the control for concentrations of up to 10 μM Hg. At higher Hg levels, both CAT and POD activities decreased. GR activity increased in leaves exposed to no more than 0.25 μM Hg, then decreased gradually. In contrast, its activity was greatly inhibited in the roots. Based on these results, we suggest that when rice plants are exposed to different concentrations of mercury, their antioxidative enzymes become involved in defense mechanisms against the free radicals that are induced by this stress.

Antioxidative responses of <i>Echinacea angustifolia</i> cultured roots to different levels of CO₂ in bioreactor liquid cultures

Ali, Mohammad Babar,Hahn, Eun Joo,Paek, Kee-Yoeup Elsevier 2006 Enzyme and microbial technology Vol.39 No.5

<P><B>Abstract</B></P><P>The effects of CO<SUB>2</SUB> levels (0.03, 0.5, 1, 2 and 5%) on growth and antioxidant responses in 5l bioreactor (working volume 4l) root suspension cultures of <I>Echinacea angustifolia</I> were studied. CO<SUB>2</SUB> caused reduction in growth, malondialdehyde content (MDA), lipoxygenase (LOX, EC 1.13.11.13) activity and superoxide anion (O<SUB>2</SUB><SUP>−</SUP>) accumulation along with high total phenols accumulation and pH levels. Maximal increases (37%) in total phenols were obtained at 1% CO<SUB>2</SUB> compared to the control. An increase in total glutathione and total ascorbate (ASC+DHA), accompanied with enhanced ascorbate–glutathione cycle enzymes were observed in CO<SUB>2</SUB>-treated roots, which played an important role for the detoxification of harmful substances. CO<SUB>2</SUB> also induced an increase in glutathione peroxidase (GPx, EC 1.11.1.9) and glutathione-<I>S</I>-transferase (GST, EC 2.5.18) activities. After native polyacrylamide gel electrophoresis (PAGE) analysis, three superoxide dismutase (SOD, EC 1.15.1.1) isoenzymes were detected. Increase in SOD and CAT (EC 1.11.16) activities observed at 0.5% CO<SUB>2</SUB>-treated roots and induced SOD activity seemed to be mainly due to Mn-SOD. However, both SOD and CAT activities were inhibited at 2 and 5% CO<SUB>2</SUB> but reached similar to control value. Three APX (EC 1.11.1.11) and three guaiacol peroxidase (G-POD, EC 1.11.1.7) isoenzymes were strongly detected, an increase in APX and G-POD activities suggests increased scavenging of ROS, indicating the tolerance to CO<SUB>2</SUB>. These results indicated that limited oxidative damage as shown by lower MDA level, low LOX activity and low O<SUB>2</SUB><SUP>−</SUP> accumulation may be due to the induced activities of antioxidant enzymes and non-enzymatic antioxidant. It is therefore, suggested that roots cultured in a bioreactor could protect themselves from CO<SUB>2</SUB> by altering the defense systems.</P>

Controlling the selectivity and deactivation of H-ZSM-5 by tuning b-axis channel length for glycerol dehydration to acrolein

Babar Ali,Xiaocheng Lan,Muhammad Tahir Arslan,Syed Zulfiqar Ali Gilani,Huanjun Wang,Tiefeng Wang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.88 No.-

Glycerol dehydration to value-added acrolein over zeolite catalysts is a useful approach to offer asustainable economic route for the biodiesel industry. Glycerol dehydration over H-ZSM-5 withconventional morphology often exhibits a significant mass transfer limitation and inhibits the access toactive sites in the micropores, which causes low activity, selectivity, and severe catalyst deactivation. Inthis study, a significant impact of b-axis channel length on acrolein selectivity and catalyst activity wasrevealed by using H-ZSM-5 synthesized with varied channel length in b-axis of 60, 130, 180, and 250 nm. Complete glycerol conversion and high acrolein selectivity (88%) were observed over H-ZSM-5 with60 nm channels length in b-axis, due to high availability of active sites and enhanced diffusion throughthe shortest channels, which dramatically suppressed the coke formation. The catalysts with long b-axischannels exhibited a slow internal diffusion, leading to increased polymerization side reactions and cokeformation.

Propagation Loss Model for Neighborhood Area Networks in Smart Grids

Muhammad Babar Ali,Wolfgang Endemann,R¨udiger Kays 한국통신학회 2022 Journal of communications and networks Vol.24 No.3

Currently the power sector is striving for theefficient utilization of its generation capabilities in existingdistributed energy networks. In future smart grids, applicationslike automated meter reading, direct load control with demandside management, and charging points for electric vehicles inmultistory parking plazas will pose a strong communicationchallenge to the RF planners. One of the main objectives isto design a realistic link budget for outdoor-to-deep-indoorwireless communication scenarios while utilizing the existinggrid infrastructure. This paper presents a realistic two-slopeempirical path loss model to predict power requirements for thewireless link between smart meters in prosumer premises andremote utility/grid devices presumably available in near vicinity. The proposed model is based on measurements performed overthree sub-gigahertz frequency bands (200 MHz, 434 MHz, and868 MHz) and the 2.4 GHz band. It supports outside, inside andin-basement deployment of the smart meter communication unit.

Effects of Oxygen Levels on Activities of Antioxidant Enzymes in Tissue Cultured Mountain Ginseng in Bioreactors

Mohammad Babar Ali,Eun-Joo Hahn(한은주),Kee-Yoeup Paek(백기엽) 한국원예학회 2004 한국원예학회 학술발표요지 Vol.2004 No.5

Copper Induced Physiological Effects and Saponin Production in Suspension Cultures Root of Panax ginseng in Bioreactor

Mohammad Babar Ali,Kee-Won Yu(유기원),Eun-Joo Hahn(한은주),Kee-Yoeup Paek(백기엽) 한국원예학회 2005 한국원예학회 학술발표요지 Vol.2005 No.5

Partial Selection of Agile Software Requirements

Davoud Mougouei,Haifeng Shen,Muhammad Ali Babar 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.1

Prioritization And Selection (PAS) of requirements is an important concern of Agile software development. Existing PAS techniques are primarily binary selection of requirements and postponing lower-priority requirements to the future. As a result, lower-priority requirements may be constantly delayed until they never have a chance to be implemented at all. However, ignoring lower-priority requirements may threaten the quality of software. In this paper, we propose the concept of partial selection as an alternative to binary selection of Agile software requirements rather than ignoring them altogether or postponing them to the future releases. We further contribute a goal-oriented framework that allows requirements to be partially satisfied when tolerated. The framework specifies the fuzzy priority of requirements and accomplishes partial selection through relaxing the satisfaction level of requirements with respect to their priority in the release backlog of software. The experimental results show that partial selection of requirements will reduce the number of neglected requirements when compared to binary selection.

Induction of Folate Sensitive Chromosomal Fragile Sites by Fudr in Pakistani Lohi Sheep (Ovis aries)

Ali, Ahmad,Babar, Masroor Ellahi,Abdullah, M. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.8

An investigation to determine frequency and distribution of folate sensitive chromosomal fragile sites was carried out in a Pakistani breed of Lohi sheep to uncover fragile site phenomena. The means and standard errors of aberrant cell count (AC) and Number of aberrations (NoA) in Lohi sheep were $0.56{\pm}0.15$ and $0.59{\pm}0.16$ in the control cultures. FUdR treated cells showed significantly higher (p<0.001) AC and NoA means ($2.18{\pm}0.33$ and $2.65{\pm}0.50$). The sex comparison for the frequency of expression indicated that males had significantly higher number of aberrant cells and total number of aberrations in FUdR cultures than the female group in Lohi sheep. The comparison of control cultures was however, not significantly different between the two groups. The regression analysis of FUdR-induced chromosomal fragility data analysis of the fragility data predicted very low ${\beta}$ of 0.325 and 0.412 for AC and NoA respectively. Lohi chromosomes expressed lesions in only 7 and 24 bands in the control and FUdR cultures respectively. The total number of significantly fragile bands in the Lohi genome was only 4. The X-chromosome of the Lohi sheep was highly stable at $5{\mu}g/ml$ FUdR with no fragile sites. The sex comparison for the distribution of fragile sites across the Lohi genome did not reveal any noticeable differences.

Design and SAR Analysis of Wearable Antenna on Various Parts of Human Body, Using Conventional and Artificial Ground Planes

Ali, Usman,Ullah, Sadiq,Khan, Jalal,Shafi, Muhammad,Kamal, Babar,Basir, Abdul,Flint, James A,Seager, Rob D. The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper presents design and specific absorption rate analysis of a 2.4 GHz wearable patch antenna on a conventional and electromagnetic bandgap (EBG) ground planes, under normal and bent conditions. Wearable materials are used in the design of the antenna and EBG surfaces. A woven fabric (Zelt) is used as a conductive material and a 3 mm thicker Wash Cotton is used as a substrate. The dielectric constant and tangent loss of the substrate are 1.51 and 0.02 respectively. The volume of the proposed antenna is $113{\times}96.4{\times}3mm^3$. The metamaterial surface is used as a high impedance surface which shields the body from the hazards of electromagnetic radiations to reduce the Specific Absorption Rate (SAR). For on-body analysis a three layer model (containing skin, fats and muscles) of human arm is used. Antenna employing the EBG ground plane gives safe value of SAR (i.e. 1.77W/kg<2W/kg), when worn on human arm. This value is obtained using the safe limit of 2 W/kg, averaged over 10g of tissue, specified by the International Commission of Non Ionization Radiation Protection (ICNIRP). The SAR is reduced by 83.82 % as compare to the conventional antenna (8.16 W/kg>2W/kg). The efficiency of the EBG based antenna is improved from 52 to 74 %, relative to the conventional counterpart. The proposed antenna can be used in wearable electronics and smart clothing.