다양한 호흡기 보호용 면체 마스크의 서브 마이크론 입자에 대한 여과 성능 평가

Zainul Alim Ali Murtadlo,조희주,박현설 한국입자에어로졸학회 2023 Particle and Aerosol Research Vol.19 No.1

Respiratory face masks are protective facepieces that are designed to filter inhaled air. They are easy-to-use devices that can protect the wearer against various hazardous particles in the air. Respiratory face masks also prevent the spread of viruses and bacteria-containing droplets that are released from the coughing or sneezing of the infected people. During the COVID-19 pandemic, various types of face masks have circulated on the market. Their ability to filter sub-micron particles, which are the sizes of harmful particulate matter and airborne viruses, needs to be investigated. Their breathability, the easiness of breath through the mask, also needs to be considered. In this study, wwe evaluated the performance of filters used for different types of face masks certified by different standards including Korean (KF94, KF80, KF-AD), USA (N95), and Chinese (KN95) standards. We also tested the filters of nanofiber masks and surgical masks for which there are no standards for filtration test. The N95 mask filters showed the highest quality factor for capturing virus-sized particles. The other types of mask filters have acceptable performance except for nanofiber mask filters whose performance is very low.

Effects of various receptor antagonists on the peripheral antinociceptive activity of aqueous extracts of Dicranopteris linearis, Melastoma malabathricum and Bauhinia purpurea leaves in mice

Zainul Amiruddin Zakaria,Nurul Husna Sodri,Halmy Hassan,Khairiyah Anuar,Fatimah Corazon Abdullah 셀메드 세포교정의약학회 2012 TANG Vol.2 No.4

The present study aimed to determine the possible mechanisms of the peripheral antinociception of the aqueous extracts of Dicranopteris linearis (AEDL), Melastoma malabathricum (AEMM) and Bauhinia purpurea (AEBP) leaves in mice. Briefly, the antinociceptive profile of each extract (300, 500, and 1000 mg/kg; subcutaneous (s.c.)), was established using the abdominal constriction test. A single dose (500 mg/kg) of each extract (s.c.) was pre-challenged for 10 min with various pain receptors’ antagonists or pain mediators’ blockers and 30 min later subjected to the antinociceptive assay to determine the possible mechanism(s) involved. Based on the results obtained, all extracts exerted significant (p < 0.05) antinociceptive activity with dose-dependent activity observed only with the AEMM. Furthermore, the antinociception of AEDL was attenuated by naloxone, atropine, yohimbine and theophylline; AEMM was reversed by yohimbine, theophylline, thioperamide, pindolol, reserpine, and 4-chloro-DL-phenylalanine methyl ester hydrochloride; and of AEBP was inhibited by naloxone, haloperidol, yohimbine and reserpine. In conclusion, the antinociceptive activity of those extracts possibly involved the activation of several pain receptors (i.e. opioids, muscarinic, 2-adrenergic and adenosine receptors, adenosine, H3-histaminergic and 5HT1A, dopaminergic receptors).

Effects of opioid and non-opioid antagonists, pH and enzymes on Corchorus olitorius antinociception in mice

Zakaria Zainul Amiruddin,Neelendran M,Pubalan S,Sulaiman MR,Fatimah CA Kyung Hee Oriental Medicine Research Center 2006 Oriental pharmacy and experimental medicine Vol.6 No.3

The present study was carried out to determine the involvement of opioid and non-opioid receptor and the effect of pH and enzymes on the recently reported antinociceptive activity of aqueous extract of Corchorus olitorius (AECO) leaves using the abdominal constriction test. The extract was prepared by soaking the dried powdered leaves of Corchorus (C.) olitorius in distilled water overnight, and the supernatant obtained was considered as a stock solution with 100% concentration/ strength. The extract, administered subcutaneously in the concentrations/ strength of 10, 50 and 100%, was found to show a significant concentration-independent antinociception. The 50% concentration AECO were further used to study on the above mentioned parameters. The extract exhibited: significant (P < 0.05) decreased in activity when pre-treated (s.c.) against 10 mg/kg naloxonazine, bicuculine (10 mg/kg), phenoxybenzamine (10 mg/kg), 10 mg/kg pindolol, and 5 mg/kg mecamylamme, but not 10 mg/kg naltrindole, 10 mg/kg atropine, respectively; significant (P < 0.05) decreased in activity after pre-treatment against 10% a-amylase, but not 1 % protease or 10% lipase and; significant (P < 0.05) decreased in activity after exposure to alkaline condition (pH between 9 and 13) while maintaining the activity at acidic condition, respectively. The C. olitorius leaves antinociception, which involved, at least in part, activation of $\mu-opioid,\;\alpha-and\;\beta-adrenergic$, and nicotinic receptors, was found to decrease under alkaline condition and in the presence of $\alpha-amylase$.

Filtration Efficiency of Electrically Charged Air Filters by a Corona Method

Murtadlo, Zainul Alim Ali,Joe, Yun-Haeng,Park, Seok-Hoon,Park, Hyun-Seol Korean Association for Particle and Aerosol Resear 2019 Particle and Aerosol Research Vol.15 No.1

The influences of corona charging parameters on collection efficiency and surface potential of air filters were investigated. A polypropylene filter medium was electrically charged using a corona charger, and the resulting surface potential and filtration efficiency against neutralized KCl particles were measured. The filter media was charged under different conditions of applied voltage, voltage polarity, charging time, and distance between electrodes. In addition, we considered charging both sides of the filter as well as charging one side of the filter. As a result, electrical force obtained by charged fiber affected filtration efficiency when the apply voltage strength was higher than 7 kV. Negatively charged filter had higher filtration efficiency than positively charged filter while the surface potential of the negatively charged filter was slightly lower than those of positively charged filter. Moreover, the filtration efficiency increased as the charging time of filter fiber increased and the distance between electrodes decreased. The filtration efficiency was more sensitive to changes of charging time than to those of electrode distance, and the efficiency of both sides charged filter was higher than that of single side charged filter.

Synthesis Of Thorium Tetrafluoride (ThF4) By Ammonium Hydrogen Difluoride (NH4HF2)

Che Nor Aniza Che Zainul Bahri,Aznan Fazli Ismail,Amran Ab. Majid 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.3

The present study aims to investigate the fluorination of thorium oxide (ThO2) by ammonium hydrogendifluoride (NH4HF2). Fluorination was performed at room temperature by mixing ThO2 and NH4HF2 atdifferent molar ratios, which was then left to react for 20 days. Next, the mixtures were analyzed using Xraydiffraction (XRD) at the intervals of 5, 10, 15, and 20 days, followed by the heating of the mixtures at450e750 C with argon gas flow. The characterization of ThF4 was established using X-ray diffraction(XRD) and scanning electron microscopyedispersion X-ray spectroscopy (SEMeEDX). In this study,ammonium thorium fluoride was synthesized through the fluorination of ThO2 at room temperature. Theoptimum molar ratio in synthesizing ammonium thorium fluoride was 1.0:5.5 (ThO2:NH4HF2) with 5days reaction time. In addition, the heating of ammonium thorium fluoride at 450 C was sufficient toproduce ThF4. Overall, this study proved that NH4HF2 is one of the fluorination agents that is capable ofsynthesizing ThF4

Anti-ulcerogenic activity of virgin coconut oil contribute to the stomach health of humankind

Malarvili Selverajah,Zainul Amiruddin Zakaria,Kamariah Long,Zuraini Ahmad,Azhar Yaacob,Muhammad Nazrul Somchit 셀메드 세포교정의약학회 2016 셀메드 (CellMed) Vol.6 No.2

The aimed of the presence study was to determine the antiulcer potential of virgin coconut oil (VCO), either extracted by wet process (VCOA) or fermentation process (VCOB), and to compare their effectiveness against the copra oil (CO) using the HCl/ethanol-induced gastric ulcer model. Earlier, the oils underwent chemical analysis to determine the free fatty acids composition, physicochemical properties and anti-oxidant capability. In the antiulcer study, rats (n = 6) were pre-treated orally for 7 consecutive days with distilled water (vehicle), 100 mg/kg ranitidine (positive group) or the respective oils (10, 50, and 100% concentration). One hour after the last test solutions administration on Day 7th, the animals were subjected to the gastric ulcer assay. Macroscopic and microscopic analyses were performed on the collected rat’s stomachs. From the results obtained, the chemical analysis revealed i) the presence of high content of lauric acid followed by myristic acid and palmitic acid in all oils and; ii) the significant (*p < 0.05) different in anisidine- and peroxide-value, percentage of free fatty acid, total phenolic content and total antioxidant activity among the oils. The animal study demonstrated that all oil possess significant (*p < 0.05) antiulcer activity with VCOB being the most effective oil followed by VCOA and CO. The macroscopic observations were supported by the microscopic findings. Interestingly, all oils were more effective than 100 mg/kg ranitidine (reference drug). In conclusion, coconut oils exert remarkable antiulcer activity depending on their methods of extraction, possibly via the modulation of its antioxidant and anti-inflammatory activity.

Mesenchymal Stromal Cells from the Maternal Segment of Human Umbilical Cord is Ideal for Bone Regeneration in Allogenic Setting

Jezamine Lim,Zainul Rashid Mohamad Razi,Jia Xian Law,Azmawati Mohammed Nawi,Ruszymah Binti Haji Idrus,Tan Geok Chin,Muaatamarulain Mustangin,Min Hwei Ng 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.1

Umbilical cord (UC) is a discarded product from the operating theatre and a ready source of mesenchymal stromal cells (MSCs). MSCs from UC express both embryonic and adult mesenchymal stem cell markers and are known to be hypoimmunogenic and non-tumorigenic and thus suitable for allogeneic cell transplantation. Our study aimed to determine the degree of immunotolerance and bone-forming capacity of osteodifferentiated human Wharton’s jelly-derived mesenchymal stromal cells (hWJ-MSCs) from different segments of UC in an allogenic setting. UCs were obtained from healthy donors delivering a full-term infant by elective Caesarean section. hWJ-MSCs were isolated from 3 cm length segment from the maternal and foetal ends of UCs. Three-dimensional fibrin constructs were formed and implanted intramuscularly into immunocompetent mice. The mice were implanted with 1) fibrin construct with maternal hWJ-MSCs, 2) fibrin construct with foetal hWJ-MSCs, or 3) fibrin without cells; the control group received sham surgery. After 1 month, the lymphoid organs were analysed to determine the degree of immune rejection and bone constructs were analysed to determine the amount of bone formed. A pronounced immune reaction was noted in the fibrin group. The maternal segment constructs demonstrated greater osteogenesis than the foetal segment constructs. Both maternal and foetal segment constructs caused minimal immune reaction and thus appear to be safe for allogeneic bone transplant. The suppression of inflammation may be a result of increased anti-inflammatory cytokine production mediated by the hWJMSC. In summary, this study demonstrates the feasibility of using bone constructs derived from hWJ-MSCs in an allogenic setting.

여과재 표면처리 방식에 따른 백필터의 탈진 및 먼지배출 특성

박현설,김동수,조희주,심준목,Zainul Alim Ali Murtadlo,조철희 한국대기환경학회 2022 한국대기환경학회지 Vol.38 No.6

This study was conducted to investigate the effect of surface treatment of filter media on the performance of bag filters. To this end, four bag filters were prepared using the different filter media made by four different surface treatment methods. Both surface and cross-sectional structures of each filter medium were examined, and the basic filtration properties of the filter media were tested. Based on the test results of the filter media, the cleaning and dust emission performance of each bag filter was evaluated using a bag filter test unit, followed by repeated filtration-cleaning cycles under dust loading conditions. As a result, the bag filters made of calendered and singed filter media with low pressure drop had cleaning intervals 3 times longer than bag filters made of membrane-laminated media. The singed filter bag, whose medium has a very porous inner structure, showed a very high concentration of dust emission which is 10 times higher than those of other bags. In addition, for the membrane-coated filter media, the pore structure of the membrane greatly affected the pressure loss of the filter media and the cleaning performance of bag filters. Among the filters tested in this work, the bag filter made of the calendered filter medium showed the best performance in terms of cleaning interval and dust emission due to the characteristics of surface and cross-sectional structure of the medium.

Comparative investigation into the anti-ulcer activity of virgin coconut oil and coconut oil in pylorous ligated animal model

Malarvili Selvarajah,Zuraini Ahmad,Zainul Amiruddin Zakaria,Hoe Siong Chiong,Yoke Kin Yong,Kamariah Long,Muhammad Nazrul Hakim 셀메드 세포교정의약학회 2015 TANG Vol.5 No.4

This current study investigated the anti-ulcer activity of 2 types of virgin coconut oil (VCO-A and VCO-B) and coconut oil (CO). Sprague-Dawley of male rats divided into 6 groups and each group consisted of ten rats. Rats were then treated with either VCO or CO and then were then anaesthetized and pyloric ligation was performed. The anaesthesia was discontinued and the animal usually recovered consciousness within less than an hour. Three hours later, the animal was then again anaesthetized and sacrificed with chloroform. Stomach removed and its content subjected to measurement of volume and pH. The results revealed VCO-B and VCO-A (100%) significantly inhibited (p < 0.001) the volume of gastric juice secreted by the control rats by 66.81% and 51.53%, respectively. Followed by CO 42.80%. While the inhibition of gastric juice for positive control rats which treated with ranitidine (100 mg/kg) was only 22.38%. The total acid output was reduced by the oils to 70.80%, 74.16% and 40.45% for VCO-A, VCO-B and CO respectively compared to control group. Ranitidine reduced the total acid output by 34.83%. In conclusion, prevention of gastric lesions in rats by VCO was found to increase the mucous and decrease the acid volume, total acid contents and ulcer scoring. The treatment of VCO affects the all parameters that influence the initiation and perpetuation of ulceration.

The Effects of Customer Value and Customer Trust on Customer Retention: An Empirical Study in Indonesia

Wiji DEWOBROTO,Umar NIMRAN,Zainul ARIFIN,Edy YULIANTO 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.7

The purpose of this study is to analyze the role of customer value and customer trust as a mediator of flexibility influence on customer retention. The study applies SEM tools with WarpPLS analysis and translates customer value and customer trust as mediation. This study was organized into three parts: exploratory research, descriptive research, and explanatory research. The quantitative approach in this study uses a survey method by taking samples from the population. This is a latent variable that is measured using a research instrument in the form of a questionnaire. The survey was conducted by distributing questionnaires to respondents. This research was conducted at PT. Nusa Prima Logistics Terminal Teluk Lamong by taking primary data, in the form of assessments or perceptions from respondents, so a survey was conducted by submitting a questionnaire directly to 194 respondents. Quantitative data analysis was performed using Structural Equation Modeling (SEM) to answer the research hypothesis. Flexibility is very influential in increasing customer retention so to develop customer retention, it is necessary to increase flexibility, customer value, and customer trust. The novelty in this research lies in identifying the role and position of customer value and customer trust as mediation that affect customer retention.