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Fulltext Opportunity for using WLAN with IEC 61850 and the future of this protocol

Ali, N.H., Borhanuddin, M. Ali, Basir, O., Hashim, F., Othman, M.L., Aker, E.

Pertanika Journal of Science & Technology, 2017;25(101):25-38.
MyJurnal

The unified protocols are unified in application interface, models, and seamless. They generate one
standard protocol, one world called IEC 61850. IEC 61850 integrate the security, interoperability,
modelling, mapping to a substation, and reliability. Presently, the more expensive fiber based Ethernet
LAN is the most prevalent technology for medium and low voltage distribution substations. To
circumvent this problem Wireless Local Area Network (WLAN) has been investigated for its suitability
for applications that are compliant to IEC 61850: automation and metering; control and monitoring; and
over-current protection. In this paper the IEEE 802.11n WLAN is studied when used in various IEC
61850 supported applications for substation automation. It also discusses the benefits of using GOOSE
message to protect and control applications and the use of IEC 61850.
Fulltext Pliable Cognitive MAC for Heterogeneous Adaptive Cognitive Radio Sensor Networks

Al-Medhwahi M, Hashim F, Ali BM, Sali A

PLoS One, 2016;11(6):e0156880.
PMID: 27257964 DOI: 10.1371/journal.pone.0156880

The rapid expansion of wireless monitoring and surveillance applications in several domains reinforces the trend of exploiting emerging technologies such as the cognitive radio. However, these technologies have to adjust their working concepts to consider the common characteristics of conventional wireless sensor networks (WSNs). The cognitive radio sensor network (CRSN), still an immature technology, has to deal with new networks that might have different types of data, traffic patterns, or quality of service (QoS) requirements. In this paper, we design and model a new cognitive radio-based medium access control (MAC) algorithm dealing with the heterogeneous nature of the developed networks in terms of either the traffic pattern or the required QoS for the node applications. The proposed algorithm decreases the consumed power on several fronts, provides satisfactory levels of latency and spectrum utilization with efficient scheduling, and manages the radio resources for various traffic conditions. An intensive performance evaluation is conducted to study the impact of key parameters such as the channel idle time length, node density, and the number of available channels. The performance evaluation of the proposed algorithm shows a better performance than the comparable protocols. Moreover, the results manifest that the proposed algorithm is suitable for real time monitoring applications.
Fulltext Clustering Transmission Opportunity Length (CTOL) Model over Cognitive Radio Network

Mohamad MH, Sali A, Hashim F, Nordin R, Takyu O

Sensors (Basel), 2018 Dec 10;18(12).
PMID: 30544655 DOI: 10.3390/s18124351

This paper investigated the throughput performance of a secondary user (SU) for a random primary user (PU) activity in a realistic experimental model. This paper proposed a sensing and frame duration of the SU to maximize the SU throughput under the collision probability constraint. The throughput of the SU and the probability of collisions depend on the pattern of PU activities. The pattern of PU activity was obtained and modelled from the experimental data that measure the wireless local area network (WLAN) environment. The WLAN signal has detected the transmission opportunity length (TOL) which was analyzed and clustered into large and small durations in the CTOL model. The performance of the SU is then analyzed and compared with static and dynamic PU models. The results showed that the SU throughput in the CTOL model was higher than the static and dynamic models by almost 45% and 12.2% respectively. Furthermore, the probability of collisions in the network and the SU throughput were influenced by the value of the minimum contention window and the maximum back-off stage. The simulation results revealed that the higher contention window had worsened the SU throughput even though the channel has a higher number of TOLs.
Fulltext Pseudorandom sequence contention algorithm for IEEE 802.11ah based internet of things network

Raouf MA, Hashim F, Liew JT, Alezabi KA

PLoS One, 2020;15(8):e0237386.
PMID: 32790697 DOI: 10.1371/journal.pone.0237386

The IEEE 802.11ah standard relies on the conventional distributed coordination function (DCF) as a backoff selection method. The DCF is utilized in the contention-based period of the newly introduced medium access control (MAC) mechanism, namely restricted access window (RAW). Despite various advantages of RAW, DCF still utilizes the legacy binary exponential backoff (BEB) algorithm, which suffers from a crucial disadvantage of being prone to high probability of collisions with high number of contending stations. To mitigate this issue, this paper investigates the possibility of replacing the existing exponential sequence (i.e., as in BEB) with a better pseudorandom sequence of integers. In particular, a new backoff algorithm, namely Pseudorandom Sequence Contention Algorithm (PRSCA) is proposed to update the CW size and minimize the collision probability. In addition, the proposed PRSCA incorporates a different approach of CW freezing mechanism and backoff stage reset process. An analytical model is derived for the proposed PRSCA and presented through a discrete 2-D Markov chain model. Performance evaluation demonstrates the efficiency of the proposed PRSCA in reducing collision probability and improving saturation throughput, network throughput, and access delay performance.
Fulltext Totally opportunistic routing algorithm (TORA) for underwater wireless sensor network

Rahman Z, Hashim F, Rasid MFA, Othman M

PLoS One, 2018;13(6):e0197087.
PMID: 29874237 DOI: 10.1371/journal.pone.0197087

Underwater Wireless Sensor Network (UWSN) has emerged as promising networking techniques to monitor and explore oceans. Research on acoustic communication has been conducted for decades, but had focused mostly on issues related to physical layer such as high latency, low bandwidth, and high bit error. However, data gathering process is still severely limited in UWSN due to channel impairment. One way to improve data collection in UWSN is the design of routing protocol. Opportunistic Routing (OR) is an emerging technique that has the ability to improve the performance of wireless network, notably acoustic network. In this paper, we propose an anycast, geographical and totally opportunistic routing algorithm for UWSN, called TORA. Our proposed scheme is designed to avoid horizontal transmission, reduce end to end delay, overcome the problem of void nodes and maximize throughput and energy efficiency. We use TOA (Time of Arrival) and range based equation to localize nodes recursively within a network. Once nodes are localized, their location coordinates and residual energy are used as a matrix to select the best available forwarder. All data packets may or may not be acknowledged based on the status of sender and receiver. Thus, the number of acknowledgments for a particular data packet may vary from zero to 2-hop. Extensive simulations were performed to evaluate the performance of the proposed scheme for high network traffic load under very sparse and very dense network scenarios. Simulation results show that TORA significantly improves the network performance when compared to some relevant existing routing protocols, such as VBF, HHVBF, VAPR, and H2DAB, for energy consumption, packet delivery ratio, average end-to-end delay, average hop-count and propagation deviation factor. TORA reduces energy consumption by an average of 35% of VBF, 40% of HH-VBF, 15% of VAPR, and 29% of H2DAB, whereas the packet delivery ratio has been improved by an average of 43% of VBF, 26% of HH-VBF, 15% of VAPR, and 25% of H2DAB. Moreover, the average end-to-end delay has been reduced by 70% of VBF, 69% of HH-VBF, 46% of VAPR, and 73% of H2DAB. Furthermore, average hope-count has been improved by 57%, 53%, 16% and 31% as compared to VBF, HHVBF, VAPR, and H2DAB, respectively. Also, propagation delay has been reduced by 34%, 30%, 15% and 23% as compared to VBF, HHVBF, VAPR, and H2DAB, respectively.
Fulltext Combinatorial Cytotoxic Effects of Gelam Honey and 5-Fluorouracil against Human Adenocarcinoma Colon Cancer HT-29 Cells In Vitro

T-Johari SAT, Hashim F, Ismail WI, Ali AM

Int J Cell Biol, 2019;2019:3059687.
PMID: 30923553 DOI: 10.1155/2019/3059687

Combination of natural products with chemodrugs is becoming a trend in discovering new therapeutics approach for enhancing the cancer treatment process. In the present study, we aimed to investigate the cytotoxic and apoptosis induction of Gelam honey (GH) combined with or without 5-Fluorouracil (5-FU) on HT-29 cells. The cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to assess cytotoxicity. Morphological changes and apoptosis were determined by the inverted microscope, Annexin V-FITC, and DNA fragmentation via flow cytometric analysis, respectively. Our results demonstrate that combined treatment revealed a remarkable and concentration-dependent cytotoxic effect on HT-29 cells in comparison with GH and 5-FU alone. Flow cytometry analysis showed that early apoptosis event was more pronounced in combined treatment. In addition, compared to 5-FU alone, apoptosis of HT-29 cells treated with combinations of GH and 5-FU demonstrated increasing percentages of fragmented DNA. Our results suggest that GH has a synergistic cytotoxic effect with 5-FU in HT-29 cell lines in vitro. Although the actions of the molecular mechanisms are not yet clear, the results reveal that the combination of GH and 5-FU could have the potential as a therapeutic agent.
Fulltext Hybrid Multi-Level Detection and Mitigation of Clone Attacks in Mobile Wireless Sensor Network (MWSN)

Shaukat HR, Hashim F, Shaukat MA, Ali Alezabi K

Sensors (Basel), 2020 Apr 17;20(8).
PMID: 32316487 DOI: 10.3390/s20082283

Wireless sensor networks (WSNs) are often deployed in hostile environments, where an adversary can physically capture some of the sensor nodes. The adversary collects all the nodes' important credentials and subsequently replicate the nodes, which may expose the network to a number of other security attacks, and eventually compromise the entire network. This harmful attack where a single or more nodes illegitimately claims an identity as replicas is known as the node replication attack. The problem of node replication attack can be further aggravated due to the mobile nature in WSN. In this paper, we propose an extended version of multi-level replica detection technique built on Danger Theory (DT), which utilizes a hybrid approach (centralized and distributed) to shield the mobile wireless sensor networks (MWSNs) from clone attacks. The danger theory concept depends on a multi-level of detections; first stage (highlights the danger zone (DZ) by checking the abnormal behavior of mobile nodes), second stage (battery check and random number) and third stage (inform about replica to other networks). The DT method performance is highlighted through security parameters such as false negative, energy, detection time, communication overhead and delay in detection. The proposed approach also demonstrates that the hybrid DT method is capable and successful in detecting and mitigating any malicious activities initiated by the replica. Nowadays, crimes are vastly increasing and it is crucial to modify the systems accordingly. Indeed, it is understood that the communication needs to be secured by keen observation at each level of detection. The simulation results show that the proposed approach overcomes the weaknesses of the previous and existing centralized and distributed approaches and enhances the performance of MWSN in terms of communication and memory overhead.
A novel antiamoebic agent against Acanthamoeba sp.--A causative agent for eye keratitis infection

Kusrini E, Hashim F, Azmi WN, Amin NM, Estuningtyas A

Spectrochim Acta A Mol Biomol Spectrosc, 2016 Jan 15;153:714-21.
PMID: 26474244 DOI: 10.1016/j.saa.2015.09.021

The terbium trinitrate.trihydrate.18-crown ether-6, Tb(NO3)3(OH2)3.(18C6) complex has been characterized by elemental analysis, photoluminescence and single X-ray diffraction. The IC50 values were determined based on MTT assay while light and fluorescence microscopy imaging were employed to evaluate the cellular morphological changes. Alkaline comet assay was performed to analyze the DNA damage. The photoluminescence spectrum of the Tb complex excited at 325 nm displayed seven luminescence peaks corresponding to the (5)D4→(7)F(0, 1, 2, 3, 4, 5, 6) transitions. The cytotoxicity and genotoxicity studies indicated that the Tb(NO3)3(OH2)3.(18C6) complex and its salt form as well as the 18C6 molecule have excellent anti-amoebic activity with very low IC50 values are 7, 2.6 and 1.2 μg/mL, respectively, with significant decrease (p<0.05) in Acanthamoeba viability when the concentration was increased from 0 to 30 μg/mL. The mode of cell death in Acanthamoeba cells following treatment with the Tb complex was apoptosis. This is in contrast to the Tb(NO3)3.6H2O salt- and 18C6 molecule-treated Acanthamoeba, which exhibited necrotic type cells. The percentage of DNA damage following treatment with all the compounds at the IC25 values showed high percentage of type 1 with the % nuclei damage are 14.15±2.4; 46.00±4.2; 36.36±2.4; 45.16±0.6%, respectively for untreated, treated with Tb complex, Tb salt and 18C6 molecule. The work features promising potential of Tb(NO3)3(OH2)3.(18C6) complex as anti-amoebic agent, representing a therapeutic option for Acanthamoeba keratitis infection.
Fulltext Corrigendum to "Combinatorial Cytotoxic Effects of Gelam Honey and 5-Fluorouracil against Human Adenocarcinoma Colon Cancer HT-29 Cells In Vitro"

T-Johari SAT, Hashim F, Ismail WIW, Ali AM

Int J Cell Biol, 2019 07 18;2019:9050626.
PMID: 31396280 DOI: 10.1155/2019/9050626

[This corrects the article DOI: 10.1155/2019/3059687.].
Fulltext SELAMAT: A New Secure and Lightweight Multi-Factor Authentication Scheme for Cross-Platform Industrial IoT Systems

Khalid H, Hashim SJ, Ahmad SMS, Hashim F, Chaudhary MA

Sensors (Basel), 2021 Feb 18;21(4).
PMID: 33670675 DOI: 10.3390/s21041428

The development of the industrial Internet of Things (IIoT) promotes the integration of the cross-platform systems in fog computing, which enable users to obtain access to multiple application located in different geographical locations. Fog users at the network's edge communicate with many fog servers in different fogs and newly joined servers that they had never contacted before. This communication complexity brings enormous security challenges and potential vulnerability to malicious threats. The attacker may replace the edge device with a fake one and authenticate it as a legitimate device. Therefore, to prevent unauthorized users from accessing fog servers, we propose a new secure and lightweight multi-factor authentication scheme for cross-platform IoT systems (SELAMAT). The proposed scheme extends the Kerberos workflow and utilizes the AES-ECC algorithm for efficient encryption keys management and secure communication between the edge nodes and fog node servers to establish secure mutual authentication. The scheme was tested for its security analysis using the formal security verification under the widely accepted AVISPA tool. We proved our scheme using Burrows Abdi Needham's logic (BAN logic) to prove secure mutual authentication. The results show that the SELAMAT scheme provides better security, functionality, communication, and computation cost than the existing schemes.
Design, synthesis and antiamoebic activity of dysprosium-based nanoparticles using contact lenses as carriers against Acanthamoeba sp

Kusrini E, Sabira K, Hashim F, Abdullah NA, Usman A, Putra N, et al.

Acta Ophthalmol, 2021 Mar;99(2):e178-e188.
PMID: 32701190 DOI: 10.1111/aos.14541

PURPOSE: Contact lenses have direct contact with the corneal surface and can induce sight-threatening infection of the cornea known as Acanthamoeba keratitis. The objective of this study was to evaluate the dysprosium-based nanoparticles (Dy-based NPs), namely Fe3 O4 -PEG-Dy2 O3 nanocomposites and Dy(OH)3 nanorods, as an active component against Acanthamoeba sp., as well as the possibility of their loading onto contact lenses as the drug administering vehicle to treat Acanthamoeba keratitis (AK).
METHODS: The Dy-based NPs were synthesized, and they were loaded onto commercial contact lenses. The loading content of the NPs and their release kinetics was determined based on the absorbance of their colloidal solution before and after soaking the contact lenses. The cytotoxicity of the NPs was evaluated, and the IC50 values of their antiamoebic activity against Acanthamoeba sp. were determined by MTT colorimetric assay, followed by observation on the morphological changes by using light microscopy. The mechanism of action of the Dy-based NPs against Acanthamoeba sp. was evaluated by DNA laddering assays.
RESULTS: The loading efficiencies of the Dy-based NPs onto the contact lens were in the range of 30.6-36.1% with respect to their initial concentration (0.5 mg ml-1 ). The Dy NPs were released with the flux approximately 5.5-11 μg cm-2 hr-1 , and the release was completed within 10 hr. The emission of the NPs consistently showed a peak at 575 nm due to Dy3+ ion, offering the possible monitoring and tracking of the NPs. The SEM images indicated the NPs are aggregated on the surface of the contact lenses. The DNA ladder assay suggested that the cells underwent DNA fragmentation, and the cell death was due most probably to necrosis, rather than apoptosis. The cytotoxicity assay of Acanthamoeba sp. suggested that Fe3 O4 -PEG, Fe3 O4 -PEG-Dy2 O3 , Dy(NO3 )3 .6H2 O and Dy(OH)3 NPs have an antiamoebic activity with the IC50 value being 4.5, 5.0, 9.5 and 22.5 μg ml-1 , respectively.
CONCLUSIONS: Overall findings in this study suggested that the Dy-based NPs can be considered as active antiamoebic agents and possess the potential as drugs against Acanthamoeba sp. The NPs could be loaded onto the contact lenses; thus, they can be potentially utilized to treat Acanthamoeba keratitis (AK).
Analysis on Target Detection and Classification in LTE Based Passive Forward Scattering Radar

Raja Abdullah RS, Abdul Aziz NH, Abdul Rashid NE, Ahmad Salah A, Hashim F

Sensors (Basel), 2016 Sep 29;16(10).
PMID: 27690051

The passive bistatic radar (PBR) system can utilize the illuminator of opportunity to enhance radar capability. By utilizing the forward scattering technique and procedure into the specific mode of PBR can provide an improvement in target detection and classification. The system is known as passive Forward Scattering Radar (FSR). The passive FSR system can exploit the peculiar advantage of the enhancement in forward scatter radar cross section (FSRCS) for target detection. Thus, the aim of this paper is to show the feasibility of passive FSR for moving target detection and classification by experimental analysis and results. The signal source is coming from the latest technology of 4G Long-Term Evolution (LTE) base station. A detailed explanation on the passive FSR receiver circuit, the detection scheme and the classification algorithm are given. In addition, the proposed passive FSR circuit employs the self-mixing technique at the receiver; hence the synchronization signal from the transmitter is not required. The experimental results confirm the passive FSR system's capability for ground target detection and classification. Furthermore, this paper illustrates the first classification result in the passive FSR system. The great potential in the passive FSR system provides a new research area in passive radar that can be used for diverse remote monitoring applications.
Fulltext Phytochemicals, mineral contents, antioxidants, and antimicrobial activities of propolis produced by Brunei stingless bees Geniotrigona thoracica, Heterotrigona itama, and Tetrigona binghami

Abdullah NA, Zullkiflee N, Zaini SNZ, Taha H, Hashim F, Usman A

Saudi J Biol Sci, 2020 Nov;27(11):2902-2911.
PMID: 33100845 DOI: 10.1016/j.sjbs.2020.09.014

The present study focused on the evaluation of phytochemical properties, essential mineral elements, and heavy metals contained in raw propolis produced by stingless bees Geniotrigona thoracica, Heterotrigona itama, and Tetrigona binghami found in the same ecological conditions and environment in Brunei Darussalam. The results indicated that propolis of the three stingless bee species mainly consisted of lipids (45.60-47.86%) and very low carbohydrate (0.17-0.48%) and protein contents (0.18-1.18%). The propolis was rich in mineral elements, thus good sources of minerals, while they contained low concentrations of all heavy metals. Propolis of the different bee species could be distinguished based on their mineral compositions. The vibrational and absorption spectra suggested that propolis contains π-conjugated aliphatic and aromatic compounds as well as aromatic acids having amine, ester, carbonyl, alkyl, and hydroxyl functional groups which might be attributed to the presence of phenolic and flavonoid compounds. The antioxidant capacity of the propolis, based on radical scavenging activity of their ethanol extract, was in line with their total phenolic content. The ethanol extract of the propolis also showed antimicrobial activities against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). The propolis showed slightly higher antibacterial activity against Gram-positive (B. subtilis and S. aureus) bacteria, indicating that the antimicrobial active compounds could be associated with flavonoids, which were quantified to be approximately comparable in all the propolis.
Fulltext A lightweight and secure online/offline cross-domain authentication scheme for VANET systems in Industrial IoT

Khalid H, Hashim SJ, Ahmad SMS, Hashim F, Akmal Chaudhary M

PeerJ Comput Sci, 2021;7:e714.
PMID: 34977343 DOI: 10.7717/peerj-cs.714

In heterogeneous wireless networks, the industrial Internet of Things (IIoT) is an essential contributor to increasing productivity and effectiveness. However, in various domains, such as industrial wireless scenarios, small cell domains, and vehicular ad hoc networks, an efficient and stable authentication algorithm is required (VANET). Specifically, IoT vehicles deal with vast amounts of data transmitted between VANET entities in different domains in such a large-scale environment. Also, crossing from one territory to another may have the connectivity services down for a while, leading to service interruption because it is pervasive in remote areas and places with multipath obstructions. Hence, it is vulnerable to specific attacks (e.g., replay attacks, modification attacks, man-in-the-middle attacks, and insider attacks), making the system inefficient. Also, high processing data increases the computation and communication cost, leading to an increased workload in the system. Thus, to solve the above issues, we propose an online/offline lightweight authentication scheme for the VANET cross-domain system in IIoT to improve the security and efficiency of the VANET. The proposed scheme utilizes an efficient AES-RSA algorithm to achieve integrity and confidentiality of the message. The offline joining is added to avoid remote network intrusions and the risk of network service interruptions. The proposed work includes two different significant goals to achieve first, then secure message on which the data is transmitted and efficiency in a cryptographic manner. The Burrows Abdi Needham (BAN logic) logic is used to prove that this scheme is mutually authenticated. The system's security has been tested using the well-known AVISPA tool to evaluate and verify its security formally. The results show that the proposed scheme outperforms the ID-CPPA, AAAS, and HCDA schemes by 53%, 55%, and 47% respectively in terms of computation cost, and 65%, 83%, and 40% respectively in terms of communication cost.
Fulltext Biomedical PEVA Nanocomposite with Dual Clay Nanofiller: Cytotoxicity, Mechanical Properties, and Biostability

Mohammed Fitri TF, Osman AF, Alosime EM, Othman R, Hashim F, Abdullah MAA

Polymers (Basel), 2021 Dec 12;13(24).
PMID: 34960896 DOI: 10.3390/polym13244345

Poly(ethylene-vinyl acetate) (PEVA) nanocomposite incorporating dual clay nanofiller (DCN) of surface modified montmorillonite (S-MMT) and bentonite (Bent) was studied for biomedical applications. In order to overcome agglomeration of the DCN, the S-MMT and Bent were subjected to a physical treatment prior to being mixed with the copolymer to form nanocomposite material. The S-MMT and Bent were physically treated to become S-MMT(P) and Bent(pH-s), respectively, that could be more readily dispersed in the copolymer matrix due to increments in their basal spacing and loosening of their tactoid structure. The biocompatibility of both nanofillers was assessed through a fibroblast cell cytotoxicity assay. The mechanical properties of the neat PEVA, PEVA nanocomposites, and PEVA-DCN nanocomposites were evaluated using a tensile test for determining the best S-MMT(P):Bent(pH-s) ratio. The results were supported by morphological studies by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Biostability evaluation of the samples was conducted by comparing the ambient tensile test data with the in vitro tensile test data (after being immersed in simulated body fluid at 37 °C for 3 months). The results were supported by surface degradation analysis. Our results indicate that the cytotoxicity level of both nanofillers reduced upon the physical treatment process, making them safe to be used in low concentration as dual nanofillers in the PEVA-DCN nanocomposite. The results of tensile testing, SEM, and TEM proved that the ratio of 4:1 (S-MMT(P):Bent(pH-s)) provides a greater enhancement in the mechanical properties of the PEVA matrix. The biostability assessment indicated that the PEVA-DCN nanocomposite can achieve much better retention in tensile strength after being subjected to the simulated physiological fluid for 3 months with less surface degradation effect. These findings signify the potential of the S-MMT(P)/Bent(pH-s) as a reinforcing DCN, with simultaneous function as biostabilizing agent to the PEVA copolymer for implant application.
Successful sperm cryopreservation of the brown-marbled grouper, Epinephelus fuscoguttatus using propylene glycol as cryoprotectant

Yusoff M, Hassan BN, Ikhwanuddin M, Sheriff SM, Hashim F, Mustafa S, et al.

Cryobiology, 2018 04;81:168-173.
PMID: 29355519 DOI: 10.1016/j.cryobiol.2018.01.005

This study developed the cryopreservation of brown-marbled grouper spermatozoa for practical application. We examined 32 cryodiluents, developed from four types of cryoprotectants [propylene glycol (PG), dimethyl-sulphoxide (Me2SO), dimethyl-acetamide (DMA) and ethylene glycol (EG)] at four concentrations of 5, 10, 15 and 20% in combination with two extenders [Fetal bovine serum (FBS) and artificial seminal plasma (ASP). Cooling rates were examined by adjusting the height of straws (2.5-12.5 cm) from the liquid nitrogen (LN) vapor and cooled for 5 min before immersion into LN. DNA laddering was used to detect DNA damage in cryopreserved sperm. In fertilization trials, 0.5 g of eggs was mixed with cryopreserved sperm stored for 30 days in LN. The best motility of post-thaw sperm was achieved using 15% PG + 85% FBS (76.7 ± 8.8%); 10% PG + 90% FBS was also effective as cryodiluent. Generally, FBS gave better post-thaw motility compared to ASP. The optimum cooling rate was at 17.6 °C min-1 obtained by freezing at the height of 7.5 cm surface of LN. The results obtained showed that cryopreserved sperm of brown-marbled grouper suffered slight DNA fragmentation, which resulted in significantly lower motility. However, the fertilization (90.9 ± 0.5%), hatching (64.5 ± 4.1%) and deformity rates (3.8 ± 0.2%) obtained from cryopreserved sperm showed no significant difference with fresh sperm. These findings show that the developed protocol for cryopreservation of brown-marbled grouper sperm was viable and will be useful for successful breeding and seed production of brown-marbled grouper.
Pre-dispersed organo-montmorillonite (organo-MMT) nanofiller: Morphology, cytocompatibility and impact on flexibility, toughness and biostability of biomedical ethyl vinyl acetate (EVA) copolymer

Osman AF, M Fitri TF, Rakibuddin M, Hashim F, Tuan Johari SAT, Ananthakrishnan R, et al.

Mater Sci Eng C Mater Biol Appl, 2017 May 01;74:194-206.
PMID: 28254285 DOI: 10.1016/j.msec.2016.11.137

Polymer-clay based nanocomposites are among the attractive materials to be applied for various applications, including biomedical. The incorporation of the nano sized clay (nanoclay) into polymer matrices can result in their remarkable improvement in mechanical, thermal and barrier properties as long as the nanofillers are well exfoliated and dispersed throughout the matrix. In this work, exfoliation strategy through pre-dispersing process of the organically modified montmorillonite (organo-MMT) nanofiller was done to obtain ethyl vinyl acetate (EVA) nanocomposite with improved flexibility, toughness, thermal stability and biostability. Our results indicated that the degree of organo-MMT exfoliation affects its cytotoxicity level and the properties of the resulting EVA nanocomposite. The pre-dispersed organo-MMT by ultrasonication in water possesses higher degree of exfoliation as compared to its origin condition and significantly performed reduced cytotoxicity level. Beneficially, this nanofiller also enhanced the EVA flexibility, thermal stability and biostability upon the in vitro exposure. We postulated that these were due to plasticizing effect and enhanced EVA-nanofiller interactions contributing to more stable chemical bonds in the main copolymer chains. Improvement in copolymer flexibility is beneficial for close contact with human soft tissue, while enhancement in toughness and biostability is crucial to extend its life expectancy as insulation material for implantable device.
Anti-amoebic activity of acyclic and cyclic-samarium complexes on Acanthamoeba

Kusrini E, Hashim F, Gunawan C, Mann R, Azmi WNNWN, Amin NM

Parasitol Res, 2018 May;117(5):1409-1417.
PMID: 29532220 DOI: 10.1007/s00436-018-5814-x

This work investigated the anti-amoebic activity of two samarium (Sm) complexes, the acyclic complex [bis(picrato)(pentaethylene glycol)samarium(III)] picrate-referred to as [Sm(Pic)2(EO5)](Pic)-and the cyclic complex [bis(picrato)(18-crown-6)samarium(III)] picrate-referred to as [Sm(Pic)2(18C6)](Pic). Both Sm complexes caused morphological transformation of the protozoa Acanthamoeba from its native trophozoite form carrying a spine-like structure called acanthopodia, to round-shaped cells with loss of the acanthopodia structure, a trademark response to environmental stress. Further investigation, however, revealed that the two forms of the Sm complexes exerted unique cytotoxicity characteristics. Firstly, the IC50 of the acyclic complex (0.7 μg/mL) was ~ 10-fold lower than IC50 of the cyclic Sm complex (6.5 μg/mL). Secondly, treatment of the Acanthamoeba with the acyclic complex caused apoptosis of the treated cells, while the treatment with the cyclic complex caused necrosis evident by the leakage of the cell membrane. Both treatments induced DNA damage in Acanthamoeba. Finally, a molecular docking simulation revealed the potential capability of the acyclic complex to form hydrogen bonds with profilin-a membrane protein present in eukaryotes, including Acanthamoeba, that plays important roles in the formation and degradation of actin cytoskeleton. Not found for the cyclic complex, such potential interactions could be the underlying reason, at least in part, for the much higher cytotoxicity of the acyclic complex and also possibly, for the observed differences in the cytotoxicity traits. Nonetheless, with IC50 values of
Fulltext Green innovation behaviour: Impact of industry 4.0 and open innovation

Ogiemwonyi O, Alam MN, Hago IE, Azizan NA, Hashim F, Hossain MS

Heliyon, 2023 Jun;9(6):e16524.
PMID: 37274640 DOI: 10.1016/j.heliyon.2023.e16524

Developing nations have motivated contemporary manufacturing companies to embrace green innovation and focus on smart technology that is sustainable to harness the growing economy and uplift the people. Although, scientific research in this direction has been neglected, and at the same time there are challenges to the attainment while meeting the need of the people. This study aims to investigate the impact of Industry 4.0, open innovation and green innovation performance on green innovation behaviour. To this end, a theoretical model was established. A quantitative research approach was applied in which survey data were utilized to capture 247 responses from different manufacturing companies in Malaysia. The model was tested using SmartPLSver3.0 to measure the structural relationship between variables. The findings indicate that Industry 4.0 and green innovation performance positively impact green innovation behaviour, compared to open innovation which has no impact. The impact of green innovation performance is found to be stronger when compared to Industry 4.0 and open innovation. Likewise, green innovation performance exhibits a substantial mediating impact between the exogenous variables and green innovation behaviour. The policy implication and conclusions are further discussed in the last section of the study.
Synthesis, anti-amoebic activity and molecular docking simulation of eugenol derivatives against Acanthamoeba sp

Zamli KM, Hashim F, Razali SA, Yusoff HM, Mohamad H, Abdullah F, et al.

Saudi Pharm J, 2023 Sep;31(9):101703.
PMID: 37546528 DOI: 10.1016/j.jsps.2023.101703

Amoebae of the genus Acanthamoeba can cause diseases such as amoebic keratitis and granulomatous amoebic encephalitis. Until now, treatment options for these diseases have not been fully effective and have several drawbacks. Therefore, research into new drugs is needed for more effective treatment of Acanthamoeba infections. Eugenol, a phenolic aromatic compound mainly derived from cloves, has a variety of pharmaceutical properties. In this study, nine eugenol derivatives (K1-K9), consisting of five new and four known compounds, were synthesized and screened for their antiamoebic properties against Acanthamoeba sp. The structure of these compounds was characterized spectroscopically by Fourier transform infrared (FTIR), Ultraviolet-Visible (UV-Vis), 1H and 13C Nuclear Magnetic Resonance (NMR) and mass spectrometer (MS). The derived molecules were screened for antiamoebic activity by determining IC50 values based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and observation of amoeba morphological changes by light and fluorescence microscopy. Most of the tested compounds possessed strong to moderate cytotoxic effects against trophozoite cells with IC50 values ranging from 0.61 to 24.83 μg/mL. Observation of amoebae morphology by light microscopy showed that the compounds caused the transformed cells to be roundish and reduced in size. Furthermore, fluorescence microscopy observation using acridine orange (AO) and propidium iodide (PI) (AO/PI) staining showed that the cells have damaged membranes by displaying a green cytoplasm with orange-stained lysosomes. Acidification of the lysosomal structure indicated disruption of the internal structure of Acanthamoeba cells when treated with eugenol derivatives. The observed biological results were also confirmed by interaction simulations based on molecular docking between eugenol derivatives and Acanthamoeba profilin. These interactions could affect the actin-binding ability of the protein, disrupting the shape and mobility of Acanthamoeba. The overall results of this study demonstrate that eugenol derivatives can be considered as potential drugs against infections caused by Acanthamoeba.

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