bluuebunny/crossref_metadata_2025 huggingface dataset:
Preoperative Heart Rate Variability as Predictors of Vagus Nerve Stimulation Outcome in Patients with Drug-resistant Epilepsy
Authors: Liu Hong-Yun , Yang Zhao , Meng Fan-Gang , Guan Yu-Guang , Ma Yan-Shan , Liang Shu-Li , Lin Jiu-Luan , Pan Long-Sheng , Zhao Ming-Ming , Qu Wei , Hao Hong-Wei , Luan Guo-Ming , Zhang Jian-Guo , Li Lu-Ming
Published: February 2018

Vagus nerve stimulation (VNS) is an adjunctive treatment for drug-resistant epilepsy (DRE). However, it is still difficult to predict which patients will respond to VNS treatment and to what extent. We aim to explore the relationship between preoperative heart rate variability (HRV) and VNS outcome. 50 healthy control subjects and 63 DRE patients who had received VNS implants and had at least one year of follow up were included. The preoperative HRV were analyzed by traditional linear methods and heart rhythm complexity analyses with multiscale entropy (MSE). DRE patients had significantly lower complexity indices (CI) as well as traditional linear HRV measurements than healthy controls. We also found that non-responders0 had significantly lower preoperative CI including Area 1–5, Area 6–15 and Area 6–20 than those in the responders0 while those of the non-responders50 had significantly lower RMSSD, pNN50, VLF, LF, HF, TP and LF/HF than the responders50. In receiver operating characteristic (ROC) curve analysis, Area 6–20 and RMSSD had the greatest discriminatory power for the responders0 and non-responders0, responders50 and non-responders50, respectively. Our results suggest that preoperative assessment of HRV by linear and MSE analysis can help in predicting VNS outcomes in patients with DRE.
Degradation shaped bacterial and archaeal communities with predictable taxa and their association patterns in Zoige wetland at Tibet plateau
Authors: Gu Yunfu , Bai Yan , Xiang Quanju , Yu Xiumei , Zhao Ke , Zhang Xiaoping , Li Chaonan , Liu Songqing , Chen Qiang
Published: February 2018

Soil microbes provide important ecosystem services. Zoige Plateau wetland, the largest alpine peat wetland in the world, has suffered from serious degradation in the past 30 years. We studied the composition of the Zoige Plateau alpine wetland soil microbiota and relations among specific taxa using 16S rRNA amplicon sequencing combined with association network analysis. Compared to the pristine swamp soil, taxons DA101,Aeromicrobium,Bradyrhizobium, andCandidatus Nitrososphaerawere enriched and several methanogenic Euryarchaeota were depleted in the moderately degraded meadow soil and highly degraded sandy soil. Soil total potassium contents in soils with different degradation levels were significantly different, being the highest in meadow soil and lowest in swamp soil. The association network analysis showed that total potassium positively correlated with specific bacterial and archaeal taxa.Jiangella,Anaerolinea,Desulfobulbus,Geobacter,Flavobacterium,MethanobacteriumandMethanosaetawere identified as the keystone genera in the networks. Soil degradation affected soil properties, and caused changes in the bacterial and archaeal community composition and the association patterns of community members. The changes could serve as early warning signals of soil degradation in alpine wetlands.
Large-scale patterning of single cells and cell clusters in hydrogels
Authors: Gong Xiangyu , Mills Kristen L.
Published: February 2018

Biophysical properties of the extracellular matrix (ECM) are known to play a significant role in cell behavior. To gain a better understanding of the effects of the biophysical microenvironment on cell behavior, the practical challenge is longitudinally monitoring behavioral variations within a population to make statistically powerful assessments. Population-level measurements mask heterogeneity in cell responses, and large-scale individual cell measurements are often performed in a one-time, snapshot manner after removing cells from their matrix. Here we present an easy and low-cost method for large-scale, longitudinal studies of heterogeneous cell behavior in 3D hydrogel matrices. Using a platform we term “the drop-patterning chip”, thousands of cells were simultaneously transferred from microwell arrays and fully embedded, only using the force of gravity, in precise patterns in 3D collagen I or Matrigel. This method allows for throughputs approaching 2D patterning methods that lack phenotypic information on cell-matrix interactions, and does not rely on special equipment and cell treatments that may result in a proximal stiff surface. With a large and yet well-organized group of cells captured in 3D matrices, we demonstrated the capability of locating selected individual cells and monitoring cell division, migration, and proliferation for multiple days.
A Highly Sensitive Detection System based on Proximity-dependent Hybridization with Computer-aided Affinity Maturation of a scFv Antibody
Authors: Wang Zhiheng , Li Yan , Liang Wenbin , Zheng Junsong , Li Shuhui , Hu Chuanmin , Chen An
Published: February 2018

The hepatitis B virus (HBV) infection is a critical health problem worldwide, and HBV preS1 is an important biomarker for monitoring HBV infection. Previously, we found that a murine monoclonal antibody, mAb-D8, targets the preS1 (aa91-107) fragment of HBV. To improve its performance, we prepared the single-chain variable region of mAb-D8 (scFvD8) and constructed the three-dimensional structure of the scFvD8-preS1 (aa91-107) complex by computer modelling. The affinity of scFvD8 was markedly increased by the introduction of mutations L96Tyr to Ser and H98Asp to Ser. Furthermore, a highly sensitive immunosensor was designed based on a proximity-dependent hybridization strategy in which the preS1 antigen competitively reacts with an antibody labelled with DNA, resulting in decreased proximity-dependent hybridization and increased electrochemical signal from the Fc fragment, which can be used for the quantisation of preS1. The results showed a wide detection range from 1 pM to 50 pM with a detection limit of 0.1 pM. The sensitivity and specificity of this immunosensor in clinical serum samples were 100% and 96%, respectively. This study provides a novel system based on proximity-dependent hybridization and the scFv antibody fragment for the rapid quantisation of antigens of interest with a high sensitivity.
An allosteric link connecting the lipid-protein interface to the gating of the nicotinic acetylcholine receptor
Authors: Domville Jaimee A. , Baenziger John E.
Published: February 2018

The mechanisms underlying lipid-sensing by membrane proteins is of considerable biological importance. A unifying mechanistic question is how a change in structure at the lipid-protein interface is translated through the transmembrane domain to influence structures critical to protein function. Gating of the nicotinic acetylcholine receptor (nAChR) is sensitive to its lipid environment. To understand how changes at the lipid-protein interface influence gating, we examined how a mutation at position 418 on the lipid-facing surface of the outer most M4 transmembrane α-helix alters the energetic couplings between M4 and the remainder of the transmembrane domain. Human muscle nAChR is sensitive to mutations at position 418, with the Cys-to-Trp mutation resulting in a 16-fold potentiation in function that leads to a congenital myasthenic syndrome. Energetic coupling between M4 and the Cys-loop, a key structure implicated in gating, do not change with C418W. Instead, Trp418 and an adjacent residue couple energetically with residues on the M1 transmembrane α-helix, leading to a reorientation of M1 that stabilizes the open state. We thus identify an allosteric link connecting the lipid-protein interface of the nAChR to altered channel function.
Transcriptional activation of zebrafish fads2 promoter and its transient transgene expression in yolk syncytial layer of zebrafish embryos
Authors: Tay Shu-Shen , Kuah Meng-Kiat , Shu-Chien Alexander Chong
Published: February 2018

The front-end desaturases (Fads) are rate-limiting enzymes responsible for production of long-chain polyunsaturated fatty acids (LC-PUFA). The full spectrum of the transcriptional regulation of fads is still incomplete, as cloning of fads promoter is limited to a few species. Here, we described the cloning and characterisation of the zebrafish fads2 promoter. Using 5′-deletion and mutation analysis on this promoter, we identified a specific region containing the sterol regulatory element (SRE) which is responsible for the activation of the fads2 promoter. In tandem, two conserved CCAAT boxes were also present adjacent to the SRE and mutation of either of these binding sites attenuates the transcriptional activation of the fads2 promoter. An in vivo analysis employing GFP reporter gene in transiently transfected zebrafish embryos showed that this 1754 bp upstream region of the fads2 gene specifically directs GFP expression in the yolk syncytial layer (YSL) region. This indicates a role for LC-PUFA in the transport of yolk lipids through this tissue layer. In conclusion, besides identifying novel core elements for transcriptional activation in zebrafish fads2 promoter, we also reveal a potential role for fads2 or LC-PUFA in YSL during development.
Lateral attachment of kinetochores to microtubules is enriched in prometaphase rosette and facilitates chromosome alignment and bi-orientation establishment
Authors: Itoh Go , Ikeda Masanori , Iemura Kenji , Amin Mohammed Abdullahel , Kuriyama Sei , Tanaka Masamitsu , Mizuno Natsuki , Osakada Hiroko , Haraguchi Tokuko , Tanaka Kozo
Published: February 2018

Faithful chromosome segregation is ensured by the establishment of bi-orientation; the attachment of sister kinetochores to the end of microtubules extending from opposite spindle poles. In addition, kinetochores can also attach to lateral surfaces of microtubules; called lateral attachment, which plays a role in chromosome capture and transport. However, molecular basis and biological significance of lateral attachment are not fully understood. We have addressed these questions by focusing on the prometaphase rosette, a typical chromosome configuration in early prometaphase. We found that kinetochores form uniform lateral attachments in the prometaphase rosette. Many transient kinetochore components are maximally enriched, in an Aurora B activity-dependent manner, when the prometaphase rosette is formed. We revealed that rosette formation is driven by rapid poleward motion of dynein, but can occur even in its absence, through slow kinetochore movements caused by microtubule depolymerization that is supposedly dependent on kinetochore tethering at microtubule ends by CENP-E. We also found that chromosome connection to microtubules is extensively lost when lateral attachment is perturbed in cells defective in end-on attachment. Our findings demonstrate that lateral attachment is an important intermediate in bi-orientation establishment and chromosome alignment, playing a crucial role in incorporating chromosomes into the nascent spindle.
Melanopsin photoreception contributes to human visual detection, temporal and colour processing
Authors: Zele Andrew J. , Feigl Beatrix , Adhikari Prakash , Maynard Michelle L. , Cao Dingcai
Published: February 2018

The visual consequences of melanopsin photoreception in humans are not well understood. Here we studied melanopsin photoreception using a technique of photoreceptor silent substitution with five calibrated spectral lights after minimising the effects of individual differences in optical pre-receptoral filtering and desensitising penumbral cones in the shadow of retinal blood vessels. We demonstrate that putative melanopsin-mediated image-forming vision corresponds to an opponent S-OFF L + M-ON response property, with an average temporal resolution up to approximately 5 Hz, and >10x higher thresholds than red-green colour vision. With a capacity for signalling colour and integrating slowly changing lights, melanopsin-expressing intrinsically photosensitive retinal ganglion cells maybe the fifth photoreceptor type for peripheral vision.
Room temperature 90° phase-matching in zirconium and magnesium co-doped lithium niobate crystals
Authors: Kong Tengfei , Liu Hongde , Ge Xinyu , Qu Da , Liu Shiguo , Chen Shaolin , Zhang Ling , Kong Yongfa , Rupp Romano , Xu Jingjun
Published: February 2018

Laser has been widely used in many aspects, by now it is difficult to get each frequency that we want, and frequency conversion is an effective way to obtain different frequency laser through a nonlinear optical crystal. MgO-doped LiNbO3 (Mg:LN) crystal has usually been used for second harmonic generation (SHG) through temperature-matching configuration with a stove, till now a room temperature 90° phase-matching is still lacking. Here we find that the SHG of Nd:YAG laser is achieved at 26.1 °C while the optical damage resistance is higher than 6.5 MW/cm2 in the ZrO2 and MgO co-doped LiNbO3 (Zr,Mg:LN) crystal. Moreover, the monotonic decrease of phase-matching temperature is firstly found with the increase of doping concentration. These unusual properties may be attributed to the formation of $${{\bf{Mg}}}_{{\bf{Li}}}^{{\boldsymbol{+}}}$$

Mg

Li

+

 + $${{\bf{Zr}}}_{{\bf{Nb}}}^{{\boldsymbol{-}}}$$

Zr

Nb

−

defect pairs. Our work suggests that Zr,Mg:LN crystal may be an attractive candidate for nonlinear optical applications.
Echinacoside Increases Sperm Quantity in Rats by Targeting the Hypothalamic Androgen Receptor
Authors: Jiang Zhihui , Zhou Bo , Li Xinping , Kirby Gordon M. , Zhang Xiaoying
Published: February 2018

Male infertility is a major health issue with an estimated prevalence of 4.2% of male infertility worldwide. Our early work demonstrated that Cistanche extracts protect against sperm damage in mice and that echinacoside (ECH) is one of the major active components. Here we report an essential role for ECH, a natural product that reverses or protects against oligoasthenospermia in rats. ECH was assayed by HPLC, the quantity and quality of sperm was evaluated and hormone levels were determined by radioimmunosorbent assay. ECH reduced levels of androgen receptor (AR) and key steroidogenic-related genes as determined by Western blot and qPCR analysis. The interaction between ECH and AR were evaluated by indirect ELISA and molecular docking. The results show that ECH combined with hypothalamic AR in the pocket of Met-894 and Val-713 to inhibit transfer of AR from the cytoplasm to nuclei in the hypothalamus. While negative feedback of sex hormone regulation was inhibited, positive feedback was stimulated to increase the secretion of luteinizing hormone and testosterone subsequently enhancing the quantity of sperm. Taken together, these data demonstrate that ECH blocks AR activity in the hypothalamus to increase the quantity of sperm and protect against oligoasthenospermia in rats.
Critical role of sigma-1 receptors in central neuropathic pain-related behaviours after mild spinal cord injury in mice
Authors: Castany Sílvia , Gris Georgia , Vela José Miguel , Verdú Enrique , Boadas-Vaello Pere
Published: February 2018

Sigma-1 receptor (σ1R) knockout (KO) CD1 mice, generated by homologous recombination, and separate pharmacological studies in wild type (WT) mice were done to investigate the role of this receptor in the development of pain-related behaviours (thermal hyperalgesia and mechanical allodynia) in mice after spinal cord contusion injury (SCI) – a model of central neuropathic pain. The modulatory effect of σ1R KO on extracellular mediators and signalling pathways in the spinal cord was also investigated. In particular, changes in the expression of inflammatory cytokines (tumour necrosis factor TNF-α, interleukin IL-1β) and both the expression and activation (phosphorylation) of the N-methyl-D-aspartate receptor subunit 2B (NR2B-NMDA) and extracellular signal-regulated kinases (ERK1/2) were analysed. Compared with WT mice, both mechanical and thermal hypersensitivity were attenuated in σ1R KO mice following SCI. Accordingly, treatment of WT mice with the σ1R antagonist MR309 (previously developed as E-52862; S1RA) after SCI exerted antinociceptive effects (i.e. reduced mechanical allodynia and thermal hyperalgesia). Attenuated nociceptive responses in σ1R KO were accompanied by reduced expression of TNF- α and IL-1β as well as decreased activation/phosphorylation of NR2B-NMDA receptors and ERK1/2. These findings suggest that σ1R may modulate central neuropathic pain and point to regulation of sensitization-related phenomena as a possible mechanism.
Functional innate immunity restricts Hepatitis C Virus infection in induced pluripotent stem cell–derived hepatocytes
Authors: Schöbel Anja , Rösch Kathrin , Herker Eva
Published: February 2018

Knowledge of activation and interplay between the hepatitis C virus (HCV) and the hosts’ innate immunity is essential to understanding the establishment of chronic HCV infection. Human hepatoma cell lines, widely used as HCV cell culture system, display numerous metabolic alterations and a defective innate immunity, hindering the detailed study of virus-host interactions. Here, we analysed the suitability of induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (iHLCs) as a physiologically relevant model to study HCV replication in vitro. Density gradients and triglyceride analysis revealed that iHLCs secreted very-low density lipoprotein (VLDL)-like lipoproteins, providing a putative platform for bona fide lipoviroparticles. iHLCs supported the full HCV life cycle, but in contrast to Huh7 and Huh7.5 cells, replication and viral RNA levels decreased continuously. Following HCV infection, interferon-stimulated gene (ISG)-expression significantly increased in iHLCs, whereas induction was almost absent in Huh7/7.5 cells. However, IFNα-stimulation equally induced ISGs in iHLCs and hepatoma cells. JAK-STAT pathway inhibition increased HCV replication in mature iHLCs, but not in Huh7 cells. Additionally, HCV replication levels where higher in STAT2-, but not STAT1-knockdown iHLCs. Our findings support iHLCs as a suitable model for HCV-host interaction regarding a functional innate immunity and lipoprotein synthesis.
Engineering Axl specific CAR and SynNotch receptor for cancer therapy
Authors: Cho Jang Hwan , Okuma Atsushi , Al-Rubaye Dalal , Intisar Ejaj , Junghans Richard P. , Wong Wilson W.
Published: February 2018

Axl is a tyrosine kinase receptor that is commonly overexpressed in many cancers. As such, Axl represents an attractive therapeutic target. The transfer of engineered T cell expressing chimeric antigen receptor (CAR) is an exciting cancer therapeutic approach that shows high efficacy against cancers in clinical trials, especially for B cell malignancies. Furthermore, recently developed synthetic Notch (synNotch) receptor has demonstrated potential in enhancing the specificity of CAR T cell therapy and delivering therapeutic payloads to tumors in an antigen-dependent manner. Therefore, a CAR or synNotch against Axl could be a valuable therapeutic reagent against many cancers. Here, we develop a single-chain variable fragment from a humanized monoclonal antibody against Axl. The scFv is attached to CD3ζ, CD28, and 4-1BB signaling domains to generate an anti-Axl CAR. When introduced into human primary T cells, the anti-Axl CAR can lead to cytokine production and cell killing in response to tumor cells expressing Axl. Moreover, an anti-Axl synNotch generated using the same scFv can be activated with Axl expressing tumor cells. Given the fact that Axl is an important cancer therapeutic target, these receptors could be valuable reagents for developing anti-Axl therapies.
Acrylic Acid Plasma Coated 3D Scaffolds for Cartilage tissue engineering applications
Authors: Cools Pieter , Mota Carlos , Lorenzo-Moldero Ivan , Ghobeira Rouba , De Geyter Nathalie , Moroni Lorenzo , Morent Rino
Published: February 2018

The current generation of tissue engineered additive manufactured scaffolds for cartilage repair shows high potential for growing adult cartilage tissue. This study proposes two surface modification strategies based on non-thermal plasma technology for the modification of poly(ethylene oxide terephthalate/poly(butylene terephthalate) additive manufactured scaffolds to enhance their cell-material interactions. The first, plasma activation in a helium discharge, introduced non-specific polar functionalities. In the second approach, a carboxylic acid plasma polymer coating, using acrylic acid as precursor, was deposited throughout the scaffolds. Both surface modifications were characterized by significant changes in wettability, linked to the incorporation of new oxygen-containing functional groups. Their capacity for chondrogenesis was studied using ATDC5 chondroblasts as a model cell-line. The results demonstrate that the carboxylic acid-rich plasma coating had a positive effect on the generation of the glucoaminoglycans (GAG) matrix and stimulated the migration of cells throughout the scaffold. He plasma activation stimulated the formation of GAGs but did not stimulate the migration of chondroblasts throughout the scaffolds. Both plasma treatments spurred chondrogenesis by favoring GAG deposition. This leads to the overall conclusion that acrylic acid based plasma coatings exhibit potential as a surface modification technique for cartilage tissue engineering applications.
Gradient reduced aeration in an enhanced aerobic granular sludge process optimizes the dominant microbial community and its function
Authors: Zhang Zhiming , Yu Zhuodong , Zhu Liang , Yu Haitian , Dai Xin , Xu Xiangyang , Alvarez Pedro J. J.
Published: February 2018

Gradient reduced aeration leads to stable granules and a significant reduction of energy consumption.
Improved performance of optical phased arrays assisted by transparent graphene nanoheaters and air trenches
Authors: Wang Yubing , Liang Lei , Chen Yongyi , Jia Peng , Qin Li , Liu Yun , Ning Yongqiang , Wang Lijun
Published: February 2018

Improved performances of optical phased arrays have been achieved assisted by graphene nanoheaters and air trenches.
A UV-visible absorption spectrum denoising method based on EEMD and an improved universal threshold filter
Authors: Li Jingwei , Tong Yifei , Guan Li , Wu Shaofeng , Li Dongbo
Published: February 2018

When using ultraviolet-visible spectroscopy (UV-visible spectroscopy) to detect water quality parameters, the measured absorption spectrum signal often contains a lot of interference information.
Economical synthesis of composites of FeNi alloy nanoparticles evenly dispersed in two-dimensional reduced graphene oxide as thin and effective electromagnetic wave absorbers
Authors: Li Juan , Zhang Dong , Qi Hui , Wang Guangming , Tang Jimin , Tian Ge , Liu Anhua , Yue Huijuan , Yu Yang , Feng Shouhua
Published: February 2018

Two-dimensional magnetic FeNi/rGO composites with excellent microwave absorbing performance have been synthesized under the assistance of glucose.
Redox and photocatalytic properties of a NiII complex with a macrocyclic biquinazoline (Mabiq) ligand
Authors: Grübel Michael , Bosque Irene , Altmann Philipp J. , Bach Thorsten , Hess Corinna R.
Published: February 2018

Upon irradiation with visible light, the NiII complex 1 is converted to the reduced form 2 in the presence of NEt3. The Ni-based photosensitizer catalyzes the cyclization of a bromoalkyl-substituted indole.
Synthesis of nitrogen doped carbon quantum dots/magnetite nanocomposites for efficient removal of methyl blue dye pollutant from contaminated water
Authors: Tadesse Aschalew , RamaDevi Dharmasoth , Hagos Mabrahtu , Battu GangaRao , Basavaiah K.
Published: February 2018

Herein, we report the green synthesis of magnetic, nitrogen doped carbon quantum dot/Fe3O4 NPs using aqueous lemon extract for the efficient removal of organic dye pollutants from contaminated water.
On the role of Ce in CO2 adsorption and activation over lanthanum species
Authors: Li Xinyu , Zhao Zhi-Jian , Zeng Liang , Zhao Jiubing , Tian Hao , Chen Sai , Li Kang , Sang Sier , Gong Jinlong
Published: February 2018

This paper describes the influence of Ce addition on the CO2 adsorption and activation over La2O3. Ce addition is verified to promote the formation of bidentate carbonate on La2O3 and affect the ratio of hexagonal/monoclinic La2O2CO3 on the Ce–La binary oxides.
Lysosomal membrane permeabilization as a cell death mechanism in cancer cells
Authors: Serrano-Puebla Ana , Boya Patricia
Published: February 2018

Lysosomes are acidic organelles that contain hydrolytic enzymes that mediate the intracellular degradation of macromolecules. Damage of these organelles often results in lysosomal membrane permeabilization (LMP) and the release into the cytoplasm of the soluble lysosomal contents, which include proteolytic enzymes of the cathepsin family. This, in turn, activates several intracellular cascades that promote a type of regulated cell death, called lysosome-dependent cell death (LDCD). LDCD can be inhibited by pharmacological or genetic blockade of cathepsin activity, or by protecting the lysosomal membrane, thereby stabilizing the organelle. Lysosomal alterations are common in cancer cells and may increase the sensitivity of these cells to agents that promote LMP. In this review, we summarize recent findings supporting the use of LDCD as a means of killing cancer cells.
Partial Least Square with Savitzky Golay Derivative in Predicting Blood Hemoglobin Using Near Infrared Spectrum
Authors: Mohd Idrus Mohd Nazrul Effendy , Chia Kim Seng
Published: February 2018

Near infrared spectroscopy (NIRS) is a reliable technique that widely used in medical fields. Partial least square was developed to predict blood hemoglobin concentration using NIRS. The aims of this paper are (i) to develop predictive model for near infrared spectroscopic analysis in blood hemoglobin prediction, (ii) to establish relationship between blood hemoglobin and near infrared spectrum using a predictive model, (iii) to evaluate the predictive accuracy of a predictive model based on root mean squared error (RMSE) and coefficient of determination rp2. Partial least square with first order Savitzky Golay (SG) derivative preprocessing (PLS-SGd1) showed the higher performance of predictions with RMSE = 0.7965 and rp2= 0.9206 in K-fold cross validation. Optimum number of latent variable (LV) and frame length (f) were 32 and 27 nm, respectively. These findings suggest that the relationship between blood hemoglobin and near infrared spectrum is strong, and the partial least square with first order SG derivative is able to predict the blood hemoglobin using near infrared spectral data.
Development of Op-Amp Based Piezoelectric Rectifier for Low Power Energy Harvesting Applications
Authors: Syazmie Bin Sepeeh Muhamad , Binti Mustafa Farahiyah , Binti Mohd Asry Anis Maisarah , Sim Sy Yi , Shafinaz Binti Zainal Abidin Mastura
Published: February 2018

In this study, the development of operational amplifier (op-amp) based rectifier for piezoelectric energy harvesting applications was studied. The two stage op-amp full wave rectifier was used to convert the AC signal to DC signal voltage received by piezoelectric devices. The inverted half wave rectifier integrated with full wave rectifier were designed and simulated using MultiSIM software. The circuit was then fabricated onto a printed circuit board (PCB), using standard fabrication process. The achievement of this rectifier was able to boost up the maximum voltage of 5 V for input voltage of 800 mV. The output of the rectifier was in DC signal after the rectification by the op-amp. In term of power, the power dissipation was reduced consequently the waste power decreases. Future work includes optimization of the rectifying circuit to operate more efficiently can be made to increase the efficiency of the devices.
An Electro-Hydraulic Servo with Intelligent Control Strategy
Authors: Mohammed Saeed , Chee Soon Chong , Ghazali Rozaimi , Yusof Ahmad Anas , Md Sam Yahaya , Mau Shern Chai
Published: February 2018

Versatile engineering applications have been developed to assist, reduce, and avoid human being from any heavy or harmful manufacturing processes. The gradually increased demand in force and position controls have simultaneously increased the usage of Electro-Hydraulic Servo (EHS) system. However, the time varying characteristics such as high-speed, outburst starting and stopping dynamic have led the EHS system to suffer from uncertainties and nonlinearities effects. Therefore, in order to enhance the performance of an EHS to surmount the uncertain and nonlinear effects, a hybrid Fuzzy-PID control strategy is developed which particularly improve the accuracy of the system by enhancing the control performance during the positioning tracking. By measuring the performance of the proposed control approach, the transient response and steady-state analysis will be performed which taking linear and intelligent control strategies as the references in the assessment process. The finding indicates the capability of a hybrid Fuzzy-PID controller in reducing the control effort applied to the EHS system.
Kalman filter estimation of RLC parameters for UMP transmission line
Authors: Mohd Amin Siti Nur Aishah , Ahmad Hamzah , Mohamed Mohd Rusllim
Published: February 2018

This paper present the development of Kalman filter that allows evaluation in the estimation of resistance (R), inductance (L), and capacitance (C) values for Universiti Malaysia Pahang (UMP) short transmission line. To overcome the weaknesses of existing system such as power losses in the transmission line, Kalman Filter can be a better solution to estimate the parameters. The aim of this paper is to estimate RLC values by using Kalman filter that in the end can increase the system efficiency in UMP. In this research, matlab simulink model is developed to analyse the UMP short transmission line by considering different noise conditions to reprint certain unknown parameters which are difficult to predict. The data is then used for comparison purposes between calculated and estimated values. The results have illustrated that the Kalman Filter estimate accurately the RLC parameters with less error. The comparison of accuracy between Kalman Filter and Least Square method is also presented to evaluate their performances.
Adsorption of Benzene by “Green” functionalization of Montmorillonite
Authors: Anjum Hirra , Obaid Mansoor Abdullah , Shamim Muhammad Yasir , Murugesan Thanabalan
Published: February 2018

The capacity of organically modified Montmorillonite (MMT) clay to adsorb nonpolar organic compound (benzene) in an aqueous solution, was investigated under the batch process. MMT was pretreated (centrifuged) and then functionalized with green intercalating agent i.e. 1-hexyl-3-methyl imadazolium chloride [HMim][Cl]. The characterization through Fourir Transoform Infrared Spectroscopy (FTIR), Differential Scanning Calorimeter (DSC) and Field Emission Scanning Electron Microscope (FE-SEM) confirmed the presence of the oxygen containing functional groups, changes in melting point and variation in the morphological properties. The governing parameters for the sorption of benzene such as the effect of contact time, pH, adsorbent dose and rotation were studied. The kinetic data conformed to pseuodo 2ndorder kinetic model and the isotherm experimental data were a better fit to Langmuir model with maximum adsorption capacity of 588.23mg/g under experimental conditions. Overall, MMT intercalated with 1-hexyl-3-methyl imadazolium chloride is a promising environmental friendly adsorbent for the abatement of benzene in an aqueous solution.
Surface Modification of Nanoclay for the Synthesis of Polycaprolactone (PCL) – Clay Nanocomposite
Authors: Yusoh Kamal , Kumaran Shamini Vesaya , Ismail Fadwa Sameeha
Published: February 2018

This paper presents a new modification method to modify the surface of nanoclay (Na-MMT) to increase its d-spacing using Aminopropylisooctyl Polyhedral Oligomeric Silsesquioxane (AP-POSS) and the fabrication of Polycaprolactone (PCL) nanocomposite through solution intercalation technique. The structure and morphology of pure nanoclay, modified nanoclay (POSS-MMT) and the PCL nanocomposite were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). XRD revealed that the d-spacing of the POSS-MMT is increased by 0.64 nm as compared to pure nanoclay. FTIR and FESEM results also showed that AP-POSS were well dispersed and intercalated throughout the interlayer space of Na-MMT. An exfoliated structure was also observed for PCL/POSS-MMT nanocomposite. Thermal properties of the nanocomposite were investigated using Thermal Gravimetry Analysis (TGA) which recorded highest degradation temperature for PCL/POSS-MMT 1% nanocomposite which is 394.1°C at 50% weight loss (T50%) but a decrease in degradation temperature when POSS-MMT content is increased and Differential Scanning Calorimetry (DSC) analysis which showed highest melting and crystallization temperature for PCL/POSS-MMT 5% nanocomposite which is 56.6°C and 32.7°C respectively whereas a decrease in degree of crystallinity for PCL/POSS-MMT nanocomposite as compared to PCL/Na-MMT nanocomposite. This study affords an efficient modification method to obtain organoclay with larger interlayer d-spacing to enhance the properties of polymer nanocomposite.
Electrochemical Evaluation of Fluorinated MnO2 for Supercapacitor Application
Authors: Mohd Yusof Siti Nur Najwa , Mohd Zain Nurul Khairiyyah , Misnon Izan Izwan , Jose Rajan
Published: February 2018

Supercapacitors (SCs) functioning as alternative energy storage is useful in most electronic devices, renewable energy system and hybrid vehicles that have high demand in these days. Excellent electrochemical performance, environment friendliness and low cost material are needed to fulfil the energy demand by most developed country. In this study, fluorination treatment on manganese oxide (MnO2) is considered as an effective way to develop better energy storage due to fluorine electronegativity and reactivity when correlate with other element. Hydrothermal method is used to synthesis MnO2 (α–MnO2 and δ–MnO2) and the effect of fluorination (Fα–MnO2 and Fδ–MnO2) on MnO2 surfaces is investigated on the charge storage ability. The crystallinity and functional groups of the samples was confirmed by the X-ray diffractogram and fourier transforms infrared spectroscopy (FTIR). The cyclic voltammetry (CV) and galvanostatic charging–discharging (CDC) analysis in 0.5 M K2SO4 electrolyte shows that F-δ-MnO2 gives the highest Cs value of 184 F g-1 at scan rate of 5 mV s-1 and 66 F g-1 at current density of 0.3 A g-1. The electrochemical impedance spectroscopy shows that the Fδ–MnO2 has the lowest electrode resistances and charge transfer resistance which contributes to high Cs and the high conductivity of electrode.
Investigation of Salt Intrusion Condition in the Belat Estuary
Authors: Gisen Jacqueline Isabella , Adnan Siti Syuhaida , Ahmad Tajudin Ahmad Amirul , Chan Tian Xian
Published: February 2018

Awareness on salt intrusion problem is still lacking in Malaysia due to high precipitation in the region. However, the El-Nino phenomenon that occurred recently has caused extremely low fresh water discharge in the Kuantan River which allowed the sea water to intrude further into its water intake region. Consequently, the Belat River may become potential water resources alternative to build new water intake station for the water supply in the Kuantan River Basin. The aims of this study are to: 1) investigate the salinity distribution in the Belat Estuary; 2) evaluate the applicability of the 1-D analytical salt intrusion solution; 3) determine the calibration parameters in the salt intrusion model. Salt intrusion measurements was conducted during the dry season at spring tide when the fresh water discharge is the minimum. Collection of data such as hydrological data, river cross section and salinity were collected to be used in the salt intrusion analysis. The results obtained show good agreement between the simulated and observed salinity distribution in the estuary with low RMSE and high NSE values. This indicates that the model is reliable and can become an important tool for water manager in conducting salt intrusion study for this area.
Effect of Polypropylene Fibres on the Thermal Conductivity of Lightweight Foamed Concrete
Authors: Jhatial Ashfaque Ahmed , Goh Wan Inn , Mohamad Noridah , Alengaram U. Johnson , Mo Kim Hung
Published: February 2018

With the reduction in the permanent load on the structure and excellent insulation properties, the lightweight foamed concrete is a potential thermal insulating building material to counter the urban heat island effect, which increases the temperature of urban areas due to the concentration of infrastructures constructed using conventional concrete that absorbs the solar radiation. The lightweight foamed concrete whose dry density ranges from 400 kg/m3 to 1600 kg/m3, has lower thermal conductivity compared to conventional concrete. But reduced density attributes to reduced compressive strength. In this study, to enhance the mechanical properties, the foamed concrete of 1600 kg/m3 density is reinforced with polypropylene fibres (PP). Four percentages of PP fibres, 0% (controlled), 0.2%, 0.25% and 0.30% were added into the foamed concrete. The compressive strength as well as the thermal conductivity of foamed concrete reinforced with PP fibres were determined. Based upon the findings, the optimum percentage of PP was determined to be 0.20% which gave higher compressive strength while thermal conductivity of foamed concrete was observed to decrease upon addition of PP fibres. Thus, addition of PP fibres improves the thermal resistance in the foamed concrete along with enhancing the mechanical properties.
Behaviour of Condensation for High Steam Energy and Water in Vertical Annular Channel
Authors: Wan Abd Rahim W.M.Faizal , Zainon M.Zamri , Nik Ghazali N.Nazri
Published: February 2018

In this paper, condensation for high steam energy in vertical annular channel was investigated. Simulations were carried out to investigate the behaviour of condensation using FLUENT 14.5 in static water and steam velocity 0.2ms-1. The results show that, the steam outer surface show rapid condensation activity effect from the steam velocity. Due to this effect, further investigate may require to show condensation behaviour with the various steam velocity.
Model Updating of Friction Stir Welding for Aluminium and Magnesium Plate Structure
Authors: Nazri Nazrotul Afina , Sani Mohd Shahrir Mohd , Mansor Muhammad Nasiruddin , Zahari Siti Norazila
Published: February 2018

Friction stir welding (FSW) of aluminium and magnesium alloys face high demands in automotive and aerospace application due to its advanced and lightweight properties. FSW is an emerging solid state joining process in which the material that is being welded does not melt and recast. The main objectives of this project are to perform model updating based on finite element analysis (FEA) and experimental modal analysis (EMA) of dissimilar material of aluminium alloy AL 7075 and magnesium alloy AZ 31B. Modal properties such as natural frequencies, mode shapes are obtained and compared between FEA and EMA. The discrepancies of first five modes natural frequencies are below than 10% and the model updating have been conducted to minimize the error between two methods. This model updating are based on sensitivity analysis in order to make sure which parameters are given more influence in this structural dynamic analysis. Young’s modulus and Poisson’s ratio both materials are selected in the model updating process. After perform model updating, total average error of the natural frequencies of dissimilar friction stir welding plate is improved significantly.
Effect of starch sizes particle as binder on short pineapple leaf fiber composite mechanical properties
Authors: Selamat Mohd Zulkefli , Zhafri Tahir Muhammad Syazwan , Kasim Ayu Natasya , Dharmalingam Sivakumar , Putra Azma , Yaakob Mohd Yuhazri , Mohd Daud Mohd Ahadlin
Published: February 2018

Pineapple leaf fiber (PLF) is one of the natural fibers that abundantly can be found in Malaysia, but the usage of the pineapple plant is limited only on their fruit and the other parts to be a waste. In this study, PLF is used as the reinforcement material and starch (SH) used as the matrix or binder. Both materials were combined with several compositions ratio (weight percentage) of PLF/SH composites which are 50PLF/50SH, 60PLF/40SH and 70PLF/30SH. Before undergo the fabrication process, the fiber has gone through an alkaline treatment to increase the strength of the fiber and chopped with an approximate size range from 0.5 mm to 5 mm. Besides that, SH powder is sieved to gain several particulate sizes which are 75 μm, 100 μm and 250 μm. The related tests such as flexural, hardness, density tests and macrostructure analysis have been done to determine their mechanical properties of composite. Based on the results, the sample with composition of 70PL/30SH with 75 μm has shown the highest result for flexural stress which is 14.49 MPa. While, the composite with the same composition of 70PLF/30SH with particulate size SH of 250 μm has shown the highest result in the hardness of 67 Shore-D and density of 1.36 g/cm3 respectively.
The Readiness Level of Using e-Learning Among Teacher Graduate Programme (TGP)
Authors: Abd Samad Noorazman , Wan Ahmad Wan Mohd Rashid , Harun Hairuddin , Mohd. Noor Siti Noor Fazelah , Ismail Affero , Abd. Rahman Mohd Wafi , Justin Randy
Published: February 2018

Using e-Learning among Teacher Graduate Programme (TGP) to students who are newly exposed in Teaching and Learning (T&L) proses. The major problem among student’s TGP is the readiness level in knowledge, attitude and skills using e-Learning during Teaching and Learning (T&L) . This study is to identify any significant differences of the knowledge level between male and female TGP students. The design of this study is to survey research using instruments of questionnaire which are distributed to respondents among TGP students at the Faculty of Technical and Vocational, UTHM. The sample is given to 248 respondents and analysis using version SPSS 21.0. Data presented using descriptive method such as, Mean, Standard Deviation(SD), inferens statistic using Mann-Whitney U to identify the knowledge difference between male and female TGP students. The result showed that the level of application of e-Learning among TGP students in terms of knowledge, attitude and skill at moderate level. The study also showed that there are no significant knowledge difference among male and female TGP students because the result of p= 0.044 value is less <0.05 can be stated that Ha failed rejected. The results of this study is important to provide awareness especially to the TGP students, lecturers and also UTHM in providing new T&L using e-Learning.
A Review of Continuing Professional Development (CPD) of Training Competencies for Malaysian Mechanical Industries
Authors: Kasman Zeti , Ismail Affero , Siron Nadzri , Abd Samad Noorazman
Published: February 2018

The aim of this paper is to review issues in continuing professional development of vocational training to the mechanical industries. The spectacle of individuals entering the labour market without relevant qualifications is common in Malaysia. There are many who choose to work instead of pursuing further education after secondary school. In the labour market, these individuals are considered to be low-skilled workers because they had no training prior to employment. The role of employers in providing training and education to employees is vital in establishing career development of employees. Employers who contributed to their employees' training funds through Human Resources Development Council would provide opportunities to increase the skills of workers. Based on the Malaysia's Development Plan of Occupational Skill, the issues and challenges that have been identified in producing skilled workers in interpersonal and technical skills. This paper provided an opportunity to examine an enterprise-based approach to skill formation for workers with basic academic qualifications. It presents an alternative scenario to institution-based Technical and Vocational Education and Training (TVET), which many Malaysians are familiar with. A structured curriculum development of human resources learning needs according to the job profile of the typical individual and group work which will provide a clearer perspective on knowledge, competence and skill levels of employee behavior in performing tasks will be discussed. The biggest impact on this study is to produce high skill employees concerning customer satisfaction and increased organizational productivity towards high income nations.
Figurative Language in Malay to English Translation: An Analysis of the 2015 UniMAP VC's Keynote Speech
Authors: Sharmini A. , Mahmood Muhammad Bazli , Jamalludin Khairul Hisham , Ridzuan Ahmad Hifzurrahaman , Abdul Halim Mohamad Zaki , Fital Siti Nurul Jannah
Published: February 2018

Translating figurative language involves more than just replacing the figurative language with its equivalent in the target language. Therefore, it is not surprising for the translation of figurative language to have its own set of challenges. Problems the translator faces in translating the Malay Figurative Language into English include complexities in understanding, interpreting and recreating the Figurative language that are unique in the Source Language (SL) culture; which have to be explained and described in Target Language (TL) where such practices and customs are non - existent. Secondly, the Source Text (ST) figurative language may appear in a variety of types and have a distinct denotative and connotative meaning and reference; most often, it is difficult to find an equivalent which totally matches the original meaning or concept. This particular paper analyses the translation of figurative language extracted from UniMAP's Vice Chancellor Keynote Speech in 2015. Findings reveal that the three categories of figurative language identified were namely idioms, metaphors and similes. Translation strategies used are either not translated, paraphrased or translated with a similar meaning but in different form.
The Roles of Product Attributes towards Generation-Y Shopping Interest
Authors: Nurul Fazura Abd Majid , Haslinda Musa , Hazmilah Hasan , Norfaridatul Akmaliah Othman , Fadhlur Rahim Azmi
Published: February 2018

Generation Y is the second largest generational cohort growing up in a world infused with brands that has been socialized in a materialistic society with purchasing power and extraordinary impact on the economy. They often involve with the shopping behavior and purchase involvement that makes their preferences towards one product would most likely depending on the attributes of the product itself. Thus, this study has developed a framework that explored the generation-Y shopping interest towards product attributes. This study applied four (4) concepts; which are the functions of the product, features of the product, benefits of the product, and generation-Y shopping interest. In this study, the researcher used empirical study by employing the questionnaire survey to investigate its managerial implications to 150 respondents of generation-Y. The data collected is analyzed by using Statistical Package for Social Science (SPSS) that showed all features of the product, functions of the product, and benefits of the product are positively affected the generation-Y shopping interest.