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Science and Technology Indonesia

JSTI
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Published by Universitas Sriwijaya

ISSN : 25804405 EISSN : 25804391 DOI : -

Core Subject : Science, Social, Engineering,

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Environmental Science Materials Science & Nanotechnology Physics

An international Peer-review journal in the field of science and technology published by The Indonesian Science and Technology Society. Science and Technology Indonesia is a member of Crossref with DOI prefix number: 10.26554/sti. Science and Technology Indonesia publishes quarterly (January, April, July, October). Science and Technology Indonesia is an international scholarly journal on the field of science and technology aimed to publish a high-quality scientific paper including original research papers, reviews, short communication, and technical notes. This journal welcomes the submission of articles that covers a typical subject of natural science and technology such as: > Chemistry > Biology > Physics > Marine Science > Pharmacy > Chemical Engineering > Environmental Science and Engineering > Computational Engineering > Biotechnology Journal Commencement: October 2016

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Articles 521 Documents

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Influence of Sepiolite Addition Methods and Contents on Physical Properties of Natural Rubber Composites Nabil Hayeemasae; Ajaman Adair; Mohamad Syahmie Mohamad Rasidi; Patiwarada Jitsopin; Abdulhakim Masa
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

The influence of sepiolite loadings (1-10 phr) and sepiolite addition procedures (mill and latex mixing approaches) on properties improvement of natural rubber composites was investigated. The viscosity, curing behavior, and tensile test were used to assess the property changes whereas the rubber-filler interactions was confirmed by using stress relaxation, swelling, Mooney-Rivlin and rheological methods. It was found that the characteristics of rubber composites influenced by both mixing methods and filler contents. Comparing between two different mixing methods, the slower stress relaxation rate and less swelling capability were achieved from mill mixing technique. This method also lowered the strain where the upturn of stress was occurred as suggested by Mooney-Rivlin plot. The greater properties enhancement of composites was obtained from milling method because of the better rubber-filler interactions, probably as a result of the nature of filler used. The greatest tensile strength improvement was achieved at 1 phr sepiolite loading where the smallest damping characteristics (tan ????) indicating the highest elastic behavior were obtained as revealed by rheological measurements. The simplicity of production and shortened step of milling procedure would be more favorable than the latex mixing approach for fabrication sepiolite filled rubber composites.

Optimization of Antibacterial Production of Endophytic Fungi with Various Sources of C, N, and pH using The Response Surface Methodology Hary Widjajanti; Elisa Nurnawati; Muharni; Eca Desriana Zahwa
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Secondary metabolites extract of McB1 endophytic fungi from gelam (Melaleuca cajuputi Powell.) leaves have a high potential antibacterial activity against Escherichia coli ATCC8739 and Staphylococcus aureus ATCC6538 with flavonoids and phenol as bioactive compound. The low production of secondary metabolites extract in the cultivation stage and the high potential antibacterial activity of bioactive compounds produced by McB1 endophytic fungi require special treatment for optimize the secondary metabolites product. This is possibly achieved by optimizing the composition of the cultivation media, where various sources of carbon, nitrogen, and pH produce different amounts and classes of secondary metabolites. The objectives of the research to obtain the optimum interaction between sources of carbon, nitrogen, and pH for the production of secondary metabolite extract using Response Surface Methodology (RSM). The results showed that the highest extract (0.25 g) with the composition of sucrose as carbon source, yeast extract as nitrogen source, and pH 6. Based on the optimization of the medium with a variation of 4.5 gL-1 sucrose, 0.48 gL-1 yeast extract, and pH 6.1 yielded 0.34 g of secondary metabolites extract of McB1 endophytic fungi. The chromatogram profile of the optimized secondary metabolite extract showed the presence of flavonoids, phenols, terpenoids, and tannins.

The Synthesis of CuO/Polystyrene Nanocomposite Superhydrophobic Layer using The Spin Coating Method Ratnawulan Ratnawulan; Ahmad Fauzi; Sarimai Sarimai
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

This paper shows the synthesis of CuO/Polystyrene(PS) nanocomposite superhydrophobic layer using the spin coating method. The objective of this study was to determine the effect of calcination temperature on the contact angle, morphology, and energy gap of the CuO/PS nanocomposite thin layer. Preparation of copper powder into copper oxide (CuO) nanoparticles using the method of High Energy 3 Dimensional Milling (HEM-3D) for 20 hours. The calcination temperature variations used were 100◦C , 150◦C, 180◦C, 200◦C, and 300◦C. In this study, sample analysis was performed using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Ultraviolet-Visible (UV-Vis) Spectrophotometry. The contact angle was determined using the sessile drop method. The findings indicate that the calcination temperature affects the contact angle of the nanocomposite thin films the highest contact angle was obtained at 162◦ at a temperature of 200◦C. The results of SEM analysis obtained that at a temperature of 200◦C, the particle size was 62.91 nm and the particles were evenly distributed in the composite layer. The energy gap at 200◦C is 2.03 eV. We found that CuO/PS synthesized at a temperature of 200◦C was superhydrophobic.

Study on Volatile Compounds of Gelatine and The Maillard Reaction Products from Different Species Using SPME-GCMS Ismarti Ismarti; Dody Dwi Handoko; Kuwat Triyana; Hamzah M. Salleh; Nurrulhidayah A. Fadzillah; Noor Faizul Hadry Nordin
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Food fraud and adulteration are the global issues, currently. One important issue is about gelatine since it comes from many sources of animals. Therefore, analytical method for gelatine must be developed and used for the authentication. This study was conducted to investigate the Volatile Compounds (VCs) of gelatine and the Maillard Reaction Products (MRPs) which are responsible to their aroma. Three gelatine standards from bovine, fish and porcine bought from Sigma Aldrich were used. A high reactivity reducing sugar namely xylose was used in the Maillard Reaction (MR). A Solid Phase Micro Extraction-Gas Chromatography-Mass Spectroscopy (SPME-GC-MS) used to evaluate the VCs in the samples. The VCs were identified by comparing the mass spectra of the compounds with database of NIST library. Moreover, retention time using the n-Alkane index were compared with literature data. There were 67 VCs have been identified. Among them, furfural, acetic acid, nonanone, dimethyl disulphide and decanone were considered as the important volatiles in gelatine due to its abundance. In the MRPs, furfural, 1-(2-furanylmethyl)-1H-pyrrole, 1-(2-furanyl)- ethanone, acetic acid and 2,2’-bifuran were predominant. Additionally, heptanol, octanal, nonanal, nonanone, dimethyl disulphide and dimethyl trisulphide could be considered as the important compounds due to its low odour threshold value. The compounds had a direct influence on the overall aroma of samples and could be potential to use in gelatine differentiation.

Chaos Theory of 0-1 Test and Logistic Map in New Confirmed COVID-19 Cases Norliza Muhamad Yusof; Muhamad Luqman Sapini; Lidiya Irdeena Az’hari; Nor Akma Hanis Roslee; Siti Noor Afiqah Rahmat; Siti Hidayah Muhad Salleh
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

This study aims to forecast the new number of positive cases of COVID-19 using the logistic map, where the presence of chaos is determined using the 0-1 Test. There are a small number of investigations on chaos utilizing the 0-1 Test and logistic map in the literature. This study provides a straightforward technique of forecasting and a current way of determining chaos. Information on new confirmed COVID-19 cases and population of ten countries involving China, Vietnam, Korea, Malaysia, Singapore, New Zealand, India, USA, Brazil, and Mexico for six months from January 20 to June 15, 2020, are selected as samples. The logistic map runs through three stages: data training, forecasting, and validation using the Mean Absolute Error method (MAE). The data training procedure is critical for determining the best growth rate, r, for the logistic map. In chaotic investigations of the 0-1 Test, there appears to be an inverse expectation toward a logistic map. The 0-1 Test in the data of new confirmed COVID-19 cases in all the selected countries reveals the presence of non-chaotic. This contrasts with the existence of chaos in the logistic map forecasts for the USA, Brazil, and Mexico. Regardless, the logistic map was found to be capable of forecasting new COVID-19 positive cases with low error instances. Beginning in the middle of May 2020, new COVID-19 positive cases are forecasted to be on the rise in the USA, Brazil, and Mexico.

A Comparative Study of Photobiological and Photophysical Characteristic of Meso-Tetraphenylporphyrin and Meso-Tetraphenylchlorin as Photosensitizers for Photodynamic Therapy Asmiyenti Djaliasrin Djalil; Susanti; Fuji Marsela Erlita; Ari Fariz Mustafa; Alwani Hamad; Suwandri
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Photosensitizer modifications are needed to improve the performance of Photodynamic Therapy (PDT) for the treatment of cancer. This work appraised the photophysical and photobiological characteristics of tetrapyrrolic macrocycles. Meso-tetraphenylporphyrin (m-TPP) and meso-tetraphenylchlorin (m-TPC) represent non-reduced and reduced pyrrole rings tetrapyrrolic macrocycles, respectively. The absorption spectra of m-TPP and m-TPC were performed. The relative quantum yield of singlet oxygen (ΦΔ) was measured at two different pH (6.3 and 7.4) relative to chlorine e6. Dark toxicity was monitored using the MTT assay on breast cancer T47D and NIH 3T3 cell lines. In addition, the stability of the compounds under indirect sunlight was also observed. The absorption maxima of the Q1 band of both compounds are at a longer wavelength. The Q1 peak of a reduced pyrrole ring is more intense than the non-reduced pyrrole ring with the lowest energy transition undergoing a redshift. The singlet oxygen generations are higher at pH 7.4 for both compounds with them-TPC showed a higher relative singlet oxygen quantum yield. In addition, the photosensitizers are stable under indirect sunlight radiation. m-TPC has higher cellular uptake than m-TPP in both cell lines. The dark toxicity of m-TPC is higher than m-TPP in T47D cells. However, the opposite occurred in observing dark toxicity in the NIH 3T3 cell line. Our study concludes that the cellular uptake and ΦΔ can be enhanced by reducing the pyrrole ring of the tetrapyrrole macrocycle. Therefore, m-TPC proved to be a better photosensitizer than m-TPP.

Antifungal Analysis of Papaya Seed Extracts and Biosynthesized Silver Nanoparticles Tri Lestari Simangunsong; Ananda Putra; Sahna Ferdinand Ginting; Fiska Maya Wardhani; Hairus Abdullah; Refi Ikhtiari
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

The purpose of research is to investigate the antifungal potential of papaya seed extract and the biosynthesis of silver nanoparticles by C. papaya extract. Here we report 14 secondary metabolites from C. papaya seed extract detected by gas chromatography mass spectroscopy. Bioactive components were majority classified as fatty acid-methyl ester, heterocyclic amides, and phenolic compounds. The proposed mechanisms of those metabolites on inducing antifungal activity were comprehensively studied. We found that the n-hexane fraction was the solely fraction to produce the silver nanoparticles. Scanning electron images presented the aggregation and evenly distribution of spherical silver nanoparticles. The XRD exhibited the crystallization of the bio-organic synthetic phase based on the specific spectrum of 2-theta at 38.9 degree with miller index [1,1,1]. The particle size analyzer also confirmed the nanoscale of synthesized materials as in the average size of 92.1 nm (Z) and 0.406 (PI). Antifungal effects were examined by disc diffusion method upon each fraction with varying concentrations of 25%, 50%, 75%, and 100% (w/w) against C. albicans. ANOVA analysis showed no significant difference among all fractions tested (p > 0.25). The antifungal activity was categorized as a moderate effect with the mean of inhibition zone ranging from 6.1 to 6.8 mm. However, the potential of papaya seed extract is relatively better than the papaya leaves extract, as previously reported. We suggest further studies on the molecular docking of the secondary metabolites against nanoparticle, and specific biomolecular analysis according to the mechanism of action.

Insecticidal Activity, Toxicity, Resistance and Metabolism of Pyrethroids: a Review Ashutosh Singh; Abhishek Singh; Preeti Singh; Archana Chakravarty; Akhilesh Singh; Priti Singh; Mahendra Kumar Mishra; Vivek Singh; Atul Kumar Srivastava; Himanshu Aggarwal; Suresh Sagadevan
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Pyrethroids are synthetic or man-made versions of natural pyrethrins discovered in the flowers of a plant species of the Compositae family called "Chrysanthemum cinerariaefolium". The plant was transported into Europe and America after it was discovered in the Near East. Commercial insecticides such as pyrethrin and synthetic pyrethroid are available. These are used to control agricultural pests as well as non-agricultural insects. They are also commercially used in personal care items such as shampoo and as a scent in insect repellent to boost efficacy and persistence in the environment, these insecticides are frequently combined with additional chemicals in diverse formulations, known as synergists. Nerve toxins, known as pyrethroids, although their chemical mechanism of action is unknown. Pyrethroids are neurotoxins, which interfere with the messages sent along nerves by maintaining sodium and chloride channels in an open position. This review presents perspectives, commercial uses and other useful characteristics features of pyrethroids based on human benefits and environmental friendly

Preparation and Evaluation of Antihypercholesterolemic Activity of Atorvastatin Calcium-Maleic Acid Co-Amorphous Solids Yudi Wicaksono; Shofiatul Izzah Al Amaliyah; Finas Rahmayanti; Viddy Agustian Rosidi; Lina Winarti; Dwi Setyawan
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Atorvastatin calcium is a statin drug used for antihypercholesterolemic. The oral bioavailability of atorvastatin calcium is relatively low because it is poorly soluble in water. The low oral bioavailability of the drug causes a decrease in its therapeutic effectiveness. This study aimed to increase the solubility of atorvastatin calcium through the formation of co-amorphous solids and evaluate its activity as antihypercholesterolemic. Atorvastatin calcium was prepared into co-amorphous solids with a maleic acid coformer using the spray drying method. Solids characterization was carried out using Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transforms Infra Red (FTIR), and Scanning Electronic Microscopy (SEM). The solubility test was carried out using the shaking method, while the evaluation of antihypercholesterolemic was carried out in vivo in experimental animals. The results of the analysis of diffractograms, thermograms, FTIR spectra, and micrograph images showed that the atorvastatin calcium-maleic acid solids prepared by spray drying were a co-amorphous solid. The atorvastatin calcium-maleic acid co-amorphous solids had a greater solubility in water (p<0.05) when compared to pure atorvastatin calcium. However, the in vivo antihypercholesterolemic activity results in experimental animals showed that the cholesterol-lowering activity of the atorvastatin calcium-maleic acid co-amorphous solidswas not significantly different (p>0.05) with pure atorvastatin calcium. This phenomenon is thought to be because atorvastatin calcium from co-amorphous solids in solution is more present as a charged fraction, affecting the permeability and absorption process.

Optimization of Liquid Smoke from Shorea pachyphylla using Response Surface Methodology and its Characterization Hasan Ashari Oramahi; Kustiati; Elvi Rusmiyanto Pancaning Wardoyo
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

The present study aims to optimize the processing variables producing liquid smoke from mabang wood (Shorea pachyphylla) by using Response Surface Methodology (RSM). In this investigation, a design of experiment with different combinations of pyrolysis temperature and pyrolysis time on the liquid smoke yield from mabang wood was applied. The response of the optimal yield, temperature, and time of pyrolysis was predicted using a mathematical model. The optimal operating conditions for the process of yielding 31.31% liquid smoke were identified at the pyrolysis temperature of 440◦C and pyrolysis time of 124 minutes. The effect of pyrolysis temperature was more significant than the pyrolysis time (p<0.05). The liquid smoke samples were evaluated by a GC-MS. The main chemical compound of the liquid smoke were 1,2-ethanediol (19.26%), fluoromethane (6.69%), formic acid (4.96%), 2-propanone (4.17%), acetic acid (18.64%), acetol (4.80%), furfural (9.94%), 2,4-hexadecanoic acid (3.45%), and guaiacol (2.93%).

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