Electrode modifier performance of TiO2 incorporated carbon quantum dots nanocomposites on Fe(CN)6 3/Fe(CN)6 4 electrochemical system

Zul Arham,Kurniawan Kurniawan 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.5

TiO2 incorporated carbon quantum dot nanocomposite, (CQDs@TiO2) was synthesized and applied as anew modifier for carbon paste electrode (CPE). The synthesis process consisted of two steps: the synthesis of a carbonquantum dot (CQDs) solution electrochemically and the synthesis of CQDs@TiO2 by impregnation. The characterizationresults show that the morphology of CQDs@TiO2 is composed of small particles with different particle sizes whichcauses the nanocomposite surface to be non-uniform. The impregnation process causes a change in the average particlesize of TiO2 from 29.32 to 33.23 nm. This process also produces new diffractograms at positions 2 =53.75o and54.95o. In addition, its process changes the specific wave number absorption (1/) TiO2 for -OH stretching (3,300 cm1to 3,369 cm1) and -OH bending (1,631 cm1 to 1,660 cm1). This shift in wavenumber was followed by the presence ofnew absorption at wavenumbers of 2,162 cm1 and 1,371 cm1. Based on the performance test of CQDs@TiO2 as aCPE modifier, it shows that CQDs@TiO2 improves CPE performance in the Fe(CN)63/Fe(CN)64 solution system. It ischaracterized by an increase in both oxide and reducing currents and a narrowing of the voltammogram peaks. Theoptimum mass of CQDs@TiO2 as a CPE modifier is 0.01 g with an electroactive surface area of 0.27 cm2. The overallresults of this work indicate that the CQDs@TiO2 nanocomposite can be applied as an electrode modifier for electrochemicalsensor applications in the future.

Production and Characterization of Cellulase from E. coli EgRK2 Recombinant Based on Oil Palm Empty Fruit Bunches

Said Zul Amraini,Lina Putri Ariyani,Heri Hermansyah,Siswa Setyahadi,Siti Fauziyah Rahman,박돈희,Misri Gozan 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.3

Oil Palm Empty Fruit Bunch (OPEFB) is an abundant biomass resource in Indonesia, which contains 41.3 ~ 46.5% (w/w) of cellulose. This research examined the production of cellulase by the E. coli EgRK2 recombinant strain using an OPEFB substrate. The production of the enzyme was initially examined to identify optimum growth conditions, by observing the growth and activity of E. coli EgRK2 compared to its wild type. Our results showed that the optimum production time, pH and temperature of the recombinant growth and cellulase activity were achieved at 24 h, and at 7 and 40°C, respectively. Using these optimum conditions, the enzyme was produced, and experiments were carried out to examine the enzyme characteristics, produced from both strains, on hydrolysis of cellulose from OPEFB. Our results showed that the activity of the enzyme produced by the recombinant almost doubled compared to that of the wild type, although the optimum pH for both strains was pH 6. Higher activity was achieved by the recombinant compared to the wild type strain, and values were 1.905 and 1.366 U/mL, respectively. The optimum temperature for hydrolysis by cellulase occurred at 50°C for Bacillus sp. RK2, and 60°C for Bacillus sp. EgRK2. The Michaelis-Menten constant (Km) and maximum velocity (Vmax) for OPEFB degradation by E. coli EgRK2 were 0.26% and 1.750 μmol/mL/sec, which were significantly better values than those of the wild type. Control experiments for the degradation test using CMC also showed a better Vmax value for E. coli EgRK2 compared to the wild type, which is 2.543 and 1.605 μmol/mL/sec, respectively.

Improving Maintenance Management Practices for Building Facility

Ismail, Zul-Atfi Korea Institute of Construction Engineering and Ma 2014 Journal of construction engineering and project ma Vol.4 No.3

The practiced conventional methods for maintenance management in Malaysian Polytechnic faced many issues due to poor service delivery, inadequate finance, poor maintenance plan and maintenance backlogs. The purpose of this study is to improve the conventional method practices which tend to be ineffective in Malaysian Polytechnic. The case studies were conducted with eight Polytechnics and are selected based on conventional method practices and its major problems. There are around 32 Polytechnics in Malaysia and almost are using conventional methods. The number is considered very big indicating that the use of modern Information and Communication Technology (ICT) is still very limited compared to other institutions of higher learning in Malaysia. The overall findings of this research indicated; poor service delivery, inadequate financial, poor maintenance planning and maintenance backlogs. There is also need to overcome less man power competencies of maintenance management practices which existed with all eight Polytechnics. The proposed system is intended to be used for maintenance management practices at Malaysian Polytechnics in order to provide high-quality of building facility with safe and healthy environments.

Genotypic Characterization of Cow Heifer’s Mastitis Origin Bacteria and Nano-Particles based Approach for Effective Management of Mastitis in Dairy Animals

Sarabpreet Kour,Neelesh Sharma,Zul-I-Huma,S. Gurdeep Singh,Dong Kee Jeong 한국동물생명공학회(구 한국동물번식학회) 2017 발생공학 국제심포지엄 및 학술대회 Vol.2017 No.10

Mastitis in dairy animals is a costliest disease worldwide and caused by more than 150 micro-organisms. Mastitis is defined as inflammation of mammary gland which is characterized by pathological changes in mammary gland and physical and chemical changes in milk. Cow heifers are the future milk producers of every dairy herd. Heifer mastitis is a disease that potentially threatens production and udder health in the first and subsequent lactation leading to economic losses for dairy farms. Unfortunately, most producers regard young heifers as uninfected, and the presence of mastitis is not observed until calving or until first signs of clinical mastitis in early lactation. Therefore, present study was focused to understand the distribution pattern of mastitis etiological agents in cow heifer’s with their molecular characterization. We found Coagulase Negative Staphylococci (CNS) as chief etiological agents of heifers mastitis followed by Staphylococcus aureus, Streptococcus spp., E. coli etc. Moelcular characterization of most prevalent bacteria was done using bacterial specific genes such as nuc gene, E. coli gene, S agl gene etc. Effective treatment of mastitis is major challenge to field veterinarians, researchers and farmers, use of traditional antibiotics have only upto 60% care rate due to various factors. Hence, we also focused to find out the alternative ways to fighting against low cure rate by developing nano-particles based approaches to improve the treatment of mastitis. We used chitosan nano-particles as vehicles for the Ciprofloxacin. Chitosan-Ciprofloxacin nano-particles were synthesized and characterized for in vitro use as antibacterial agent against mastitis origin bacteria. Present study found that Chitosan-Ciprofloxacin nano-particles had good antibacterial activity with the slow release properties.

A Modified E-LEACH Routing Protocol for Improving the Lifetime of a Wireless Sensor Network

Maman Abdurohman,Yadi Supriadi,Fitra Zul Fahmi 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.4

This paper proposes a modified endtoend secure low energy adaptive clustering hierarchy (MELEACH) algorithm for enhancing the lifetime of a wireless sensor network (WSN). Energy limitations are a major constraint in WSNs, hence every activity in a WSN must efficiently utilize energy. Several protocols have beenintroduced to modulate the way a WSN sends and receives information. The endtoend secure low energy adaptive clustering hierarchy (ELEACH) protocol is a hierarchical routing protocol algorithm proposed to solve highenergy dissipation problems. Other methods that explore the presence of the most powerful nodeson each cluster as cluster heads (CHs) are the sparsityaware energy efficient clustering (SEEC) protocol and an energy efficient clusteringbased routing protocol that uses an enhanced cluster formation technique accompanied by the fuzzy logic (EERRCUF) method. However, each CH in the ELEACH method sends data directly to the base station causing high energy consumption. SEEC uses a lot of energy to identify the most powerful sensor nodes, while EERRCUF spends high amounts of energy to determine the super cluster head (SCH). In the proposed method, a CH will search for the nearest CH and use it as the next hop. The formation of CH chains serves as a path to the base station. Experiments were conducted to determine the performance of the MELEACH algorithm. The results show that MELEACH has a more stable and higher throughput than SEEC and EERRCUF and has a 35.2% better network lifetime than the ELEACH algorithm.

Evaluation of acaricide resistance of Tetranychus urticae at the strawberry fields

Md. Munir Mostafiz,Matabaro Joseph Malekera,Olha Muzhanovska,Zul Norain Sajid,Kyeong-Yeoll Lee 한국응용곤충학회 2023 한국응용곤충학회 학술대회논문집 Vol.2023 No.04

Significance of immune checkpoint proteins in <i>EGFR</i>-mutant non-small cell lung cancer

Soo, Ross A.,Kim, Hye Ryun,Asuncion, Bernadette Reyna,Fazreen, Zul,Omar, Mohamed Feroz Mohd,Herrera, Maria Cynthia,Yun Lim, Joey Sze,Sia, Grace,Soong, Richie,Cho, Byoung-Chul Elsevier 2017 Lung cancer Vol.105 No.-

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>To characterize the expression of PD-L1, PD-1, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3) in epidermal growth factor receptor (<I>EGFR</I>) mutant non-small cell lung cancer (NSCLC).</P> <P><B>Materials and methods</B></P> <P>Samples from 90 patients with newly diagnosed advanced stage NSCLC harboring <I>EGFR</I> mutations and treated with first line EGFR tyrosine kinase inhibitors (TKI) within 3 months of diagnosis were stained for CTLA-4, PD-L1, PD-1, TIM-3 and CD3 expression by immunohistochemistry.</P> <P><B>Results</B></P> <P>PD-L1 was present in at least 1% of immune and tumor cells in 44% and 59% of samples, respectively. In multivariate analysis, increased CD3 immune shaped cell (ISC) counts (HR 2.805, <I>p</I> =0.034) and high PD-L1 tumor H-score (HR 3.805, <I>p</I> =0.022) was associated with a shorter progression free survival and high CTLA-4 ISC counts was associated with borderline overall survival significance (HR 1.054, <I>p</I> =0.061).</P> <P><B>Conclusion</B></P> <P>Tumor PD-L1 expression was significantly associated with a shorter PFS whereas immune cell CTLA-4 may be prognostic for OS. Our findings support the ongoing development of CTLA-4 and PD1/PD-L1 inhibitors in this important molecularly defined subset of lung adenocarcinoma.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Casesof advanced stage EGFR mutant NSCLC were analysed. </LI> <LI> PD-L1, PD-1, CTLA-4 and TIM3 expression were characterized. </LI> <LI> High tumor PD-L1 had a shorter PFS. </LI> <LI> Immune cell CTLA-4 expression was prognostic. </LI> </UL> </P>

Toxoplasma gondii virulence prediction using hierarchical cluster analysis based on coding sequences (CDS) of sag1, gra7 and rop18

Didik T Subekti,Fitrine Ekawasti,Muhammad Ibrahim Desem,Zul Azmi 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.6

Toxoplasma gondii consists of three genotypes, namely genotype I, II and III. Based on its virulence, T. gondii can be divided into virulent and avirulent strains. This study intends to evaluate an alternative method for predicting T. gondii virulence using hierarchical cluster analysis based on complete coding sequences (CDS) of sag1, gra7 and rop18 genes. Dendrogram was constructed using UPGMA with a Kimura 80 nucleotide distance measurement. The results showed that the prediction errors of T. gondii virulence using sag1, gra7 and rop18 were 7.41%, 6.89% and 9.1%, respectively. Analysis based on CDS of gra7 and rop18 was able to differentiate avirulent strains into genotypes II and III, whereas sag1 failed to differentiate.

Nanocomposite design of graphene modified TiO2 for electrochemical sensing in phenol detection

Muhammad Nurdin,Maulidiyah Maulidiyah,Abdul Haris Watoni,Armawansa Armawansa,La Ode Agus Salim,Zul Arham,Dwiprayogo Wibowo,Irwan Irwan,Akrajas Ali Umar 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.1

This study is the stage of developing a phenol detection electrochemical sensor. Phenol is one of the organic pollutants harmful to human life and ecosystems. The development of this sensor was carried out by studying the use of TiO2 anatase as a modifier of graphene electrodes. The mass of TiO2 anatase was varied, while the mass of graphene and paraffin was fixed. The results showed that the TiO2 mass of 1.0 g was the best mass as a graphene electrode modifier. The use of this mass increases the oxidation current (Ipa) of phenol by 450 A, which is observed at an oxidation potential (Epa) of −0.30 V. The presence of interfering ions such as K+, Fe2+, and OH− can decrease the measurement current. However, based on the %RSD value, it shows that the performance of TiO2-graphene is in a good category, where the %RSD value obtained is 0.6%. TiO2-graphene electrodes can be used repeatedly for 12 days. Overall, this work demonstrates the potential of TiO2-graphene electrodes as electrode candidates for electrochemical-based phenol sensors.

Vital parameters for high gamma-aminobutyric acid (GABA) production by an industrial soy sauce koji Aspergillus oryzae NSK in submerged-liquid fermentation

Wan Abd Al Qadr Imad Wan-Mohtar,Safuan Ab Kadir,Sarina Abdul Halim Lim,Zul Ilham,Siti Hajar-Azhari,Nazamid Saari 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.6

In submerged-liquid fermentation, seven keyparameters were assessed using one-factor-at-a-time toobtain the highest GABA yield using an industrial soysauce koji Aspergillus oryzae strain NSK (AOSNSK). AOSNSK generated maximum GABA at 30 C (194 mg/L) and initial pH 5 (231 mg/L), thus was able to utilizesucrose (327 mg/L of GABA) for carbon source. Sucrose at100 g/L, improved GABA production at 646 mg/L. Singlenitrogen sources failed to improve GABA production,however a combination of yeast extract (YE) and glutamicacid (GA) improved GABA at 646.78 mg/L. Carbon-tonitrogenratio (C8:N3) produced the highest cell (24.01 g/L) and GABA at a minimal time of 216 h. The keyparameters of 30 C, initial pH 5, 100 g/L of sucrose,combination YE and GA, and C8:N3 generated the highestGABA (3278.31 mg/L) in a koji fermentation. AOSNSKpromisingly showed for the development of a new GABArichsoy sauce.