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Fulltext Neobenedenia melleni Parasite of Red Snapper, Lutjanus erythropterus, with Regression Statistical Analysis between Fish Length, Temperature, and Parasitic Intensity in Infected Fish, Cultured at Jerejak Island, Penang, Malaysia

Ravi R, Yahaya ZS

J Parasitol Res, 2016;2016:1946283.
PMID: 27190634 DOI: 10.1155/2016/1946283

The fish parasites collected from Lutjanus erythropterus fish species showed a correlation with parasitic intensity, fish size, and temperature, and statistical model summary was produced using SPSS version 20, statistical software. Statistical model summary concluded that among the variables which significantly predict the prevalence of Neobenedenia melleni parasites are fish length and water temperature, both significant at 1% and 5%. Furthermore, the increase in one unit of fish length, holding other variables constant, increases the prevalence of parasite by approximately 1 (0.7≈1) unit. Also, increasing the temperature from 32°C to 33°C will positively increase the number of parasites by approximately 0.32 units, holding other variables constant. The model can be summarized as estimated number of Neobenedenia melleni parasites = 8.2 + 0.7 ⁎ (fish length) + 0.32 ⁎ (water temperature). Next, this study has also shown the DNA sequence and parasitic morphology of Neobenedenia melleni. Nucleotide sequence for 18s ribosomal gene RNA in this study showed 99% similarity with N. melleni EU707804.1 from GenBank. Finally, all the sequence of Neobenedenia melleni in this study was deposited in GenBank with accession numbers of KU843501, KU843502, KU843503, and KU843504.
Regulatory landscape, risks, and solutions for refurbished medical devices: a comparative analysis in the US, EU, Malaysia, and Ghana

Pinheiro AM, Chettri B, Mehra A, Deepti I, Ravi R

Expert Rev Med Devices, 2024 Aug 09.
PMID: 39119692 DOI: 10.1080/17434440.2024.2390581

INTRODUCTION: Refurbished medical devices are previously owned equipment that undergo a process of restoration to ensure they meet quality standards and function effectively. The utilization of refurbished medical devices, coupled with the integration of software, poses intricate challenges in terms of regulatory compliance, risk management, and patient safety.
AREAS COVERED: This article explores the regulatory frameworks governing refurbished medical devices in the United States (US), the European Union (EU), Malaysia, and Ghana. Included information from a range of primary and secondary sources. Additionally, it aims to identify and analyze the risks associated with refurbished medical devices, with a specific focus on the implications of software integration, and recommend practical solutions for mitigating these risks.
EXPERT OPINION: The landscape of refurbished medical devices presents challenges in terms of regulatory compliance, risk management, and patient safety. Addressing these challenges requires careful consideration and strategies to ensure that refurbished devices meet stringent quality standards. By focusing on these areas, policymakers and healthcare professionals can enhance the safe utilization of refurbished medical devices, thereby improving access to quality healthcare, particularly in underserved regions.
Fulltext The potential use of Azolla pinnata as an alternative bio-insecticide

Ravi R, Rajendran D, Oh WD, Mat Rasat MS, Hamzah Z, Ishak IH, et al.

Sci Rep, 2020 11 06;10(1):19245.
PMID: 33159109 DOI: 10.1038/s41598-020-75054-0

Four different tests showed the effectiveness of Azolla pinnata plant extracts against Aedes aegypti and Aedes albopictus mosquitoes. In the adulticidal test, there was a significant increase in mortality as test concentration increases and A. pinnata extracts showed LC50 and LC95 values of 2572.45 and 6100.74 ppm, respectively, against Ae. aegypti and LC50 and LC95 values of 2329.34 and 5315.86 ppm, respectively, against Ae. albopictus. The ovicidal test showed 100% eggs mortality for both species tested for all the concentrations tested at 1500 ppm, 1000 ppm, 500 ppm, 250 ppm and 125 ppm. Both tested samples of Ae. aegypti and Ae. albopictus did not lay any eggs in the plastic cups filled with the A. pinnata extract but instead opted to lay eggs in the plastic cups filled with water during the oviposition deterrence test. Similarly, the non-choice test of Ae. aegypti mosquitoes laid eggs on the sucrose solution meant for the nutrient source of the mosquitoes instead of in the plastic cup that was designed to facilitate oviposition filled with the extract. This clearly indicates the presence of bioactive compounds which are responsible in adulticidal and ovicidal activity in Aedes mosquitoes and at the same time inducing repellence towards the mosquitoes. The LC-MS results showed mainly three important chemical compounds from A. pinnata extracts such as 1-(O-alpha-D-glucopyranosyl)-(1,3R,25R)-hexacosanetriol, Pyridate and Nicotinamide N-oxide. All these chemicals have been used for various applications such as both emulsion and non-emulsion type of cosmetics, against mosquito vector such as Culex pipens and Anopheles spp. Finally, the overall view of these chemical components from A. pinnata extracts has shown the potential for developing natural product against dengue vectors.
Fulltext Systematic Performance Comparison of Fe3+/Fe0/Peroxymonosulfate and Fe3+/Fe0/Peroxydisulfate Systems for Organics Removal

Oh WD, Ho YC, Mohamad M, Ho CD, Ravi R, Lim JW

Materials (Basel), 2021 Sep 14;14(18).
PMID: 34576510 DOI: 10.3390/ma14185284

Activated zero-valent iron (Ac-ZVI) coupled with Fe3+ was employed to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) for acid orange 7 (AO7) removal. Fe3+ was used to promote Fe2+ liberation from Ac-ZVI as an active species for reactive oxygen species (ROS) generation. The factors affecting AO7 degradation, namely, the Ac-ZVI:Fe3+ ratio, PMS/PDS dosage, and pH, were compared. In both PMS and PDS systems, the AO7 degradation rate increased gradually with increasing Fe3+ concentration at fixed Ac-ZVI loading due to the Fe3+-promoted liberation of Fe2+ from Ac-ZVI. The AO7 degradation rate increased with increasing PMS/PDS dosage due to the greater amount of ROS generated. The degradation rate in the PDS system decreased while the degradation rate in the PMS system increased with increasing pH due to the difference in the PDS and PMS activation mechanisms. On the basis of the radical scavenging study, sulfate radical was identified as the dominant ROS in both systems. The physicochemical properties of pristine and used Ac-ZVI were characterized, indicating that the used Ac-ZVI had an increased BET specific surface area due to the formation of Fe2O3 nanoparticles during PMS/PDS activation. Nevertheless, both systems displayed good reusability and stability for at least three cycles, indicating that the systems are promising for pollutant removal.
Fulltext Chemical composition and larvicidal activities of Azolla pinnata extracts against Aedes (Diptera:Culicidae)

Ravi R, Zulkrnin NSH, Rozhan NN, Nik Yusoff NR, Mat Rasat MS, Ahmad MI, et al.

PLoS One, 2018;13(11):e0206982.
PMID: 30399167 DOI: 10.1371/journal.pone.0206982

BACKGROUND: The resistance problem of dengue vectors to different classes of insecticides that are used for public health has raised concerns about vector control programmes. Hence, the discovery of alternative compounds that would enhance existing tools is important for overcoming the resistance problem of using insecticides in vectors and ensuring a chemical-free environment. The larvicidal effects of Azolla pinnata extracts by using two different extraction methods with methanol solvent against Aedes in early 4th instar larvae was conducted.
METHODS: The fresh Azolla pinnata plant from Kuala Krai, Kelantan, Malaysia was used for crude extraction using Soxhlet and maceration methods. Then, the chemical composition of extracts and its structure were identified using GCMS-QP2010 Ultra (Shimadzu). Next, following the WHO procedures for larval bioassays, the extracts were used to evaluate the early 4th instar larvae of Aedes mosquito vectors.
RESULTS: The larvicidal activity of Azolla pinnata plant extracts evidently affected the early 4th instar larvae of Aedes aegypti mosquito vectors. The Soxhlet extraction method had the highest larvicidal effect against Ae. aegypti early 4th instar larvae, with LC50 and LC95 values of 1093 and 1343 mg/L, respectively. Meanwhile, the maceration extraction compounds were recorded with the LC50 and LC95 values of 1280 and 1520 mg/L, respectively. The larvae bioassay test for Ae. albopictus showed closely similar values in its Soxhlet extraction, with LC50 and LC95 values of 1035 and 1524 mg/L, compared with the maceration extraction LC50 and LC95 values of 1037 and 1579 mg/L, respectively. The non-target organism test on guppy fish, Poecilia reticulata, showed no mortalities and posed no toxic effects. The chemical composition of the Azolla pinnata plant extract has been found and characterized as having 18 active compounds for the Soxhlet method and 15 active compounds for the maceration method.
CONCLUSIONS: Our findings showed that the crude extract of A. pinnata bioactive molecules are effective and have the potential to be developed as biolarvicides for Aedes mosquito vector control. This study recommends future research on the use of active ingredients isolated from A. pinnata extracts and their evaluation against larvicidal activity of Aedes in small-scale field trials for environmentally safe botanical insecticide invention.
Larvicidal Effectiveness of Azolla pinnata against Aedes aegypti (Diptera: Culicidae) with Its Effects on Larval Morphology and Visualization of Behavioural Response

Husna Zulkrnin NS, Rozhan NN, Zulkfili NA, Nik Yusoff NR, Rasat MSM, Abdullah NH, et al.

J Parasitol Res, 2018;2018:1383186.
PMID: 30050688 DOI: 10.1155/2018/1383186

Dengue is vector-borne diseases with 390 million infections per year extending over 120 countries of the world. Aedes aegypti (L.) (Diptera: Culicidae) is a primary vector for dengue viral infections for humans. Current focus on application of natural product against mosquito vectors has been the main priority for research due to its eco-safety. The extensive use of chemical insecticides has led to severe health problems, environmental pollution, toxic hazards to human and nontarget species, and development of insecticide resistance on mosquitoes. Azolla pinnata is an aquatic fern and predominantly used as feed in poultry industry and as fertilizer in agricultural field for enhancing the fertility of rice paddy soil. The present study was conducted to explore the larvicidal efficacy of A. pinnata using fresh and powdered form against late third-stage larvae (6 days, 5 mm in larvae body length) of Ae. aegypti (L.) (Diptera: Culicidae). The larvicidal bioassays were performed using World Health Organization standard larval susceptibility test method for different concentration for powdered and fresh A. pinnata. Powdered A. pinnata concentration used during larvicidal bioassay ranges from 500ppm to 2000ppm; meanwhile, fresh A. pinnata ranges from 500ppm to 9,000,000 ppm. The highest mortality was at 1853 ppm for powdered A. pinnata compared with fresh A. pinnata at 2,521,535 ppm, while the LC50 for both powdered and fresh A. pinnata recorded at 1262 ppm and 1853 ppm, respectively. Finally, the analysis of variance (ANOVA) showed significant difference on Ae. aegypti larval mortality (F=30.439, df=1, p≤0.001) and concentration (F=20.002, df=1, p≤0.001) compared to powdered and fresh A. pinnata at 24-hour bioassay test. In conclusion, the powdered A. pinnata serves as a good larvicidal agent against Ae. aegypti (L.) (Diptera: Culicidae) and this study provided information on the lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program.
Fulltext Oral Health-Related Quality of Life Among Non-institutionalized Elderly in Malaysia: A Teaching Hospital-Based Survey

Ramien AS, Azmi AAB, Ravichandran S, Wai Li TT, Ravendran S, Kyaw Soe HH, et al.

Cureus, 2024 Mar;16(3):e56202.
PMID: 38618473 DOI: 10.7759/cureus.56202

Background In Malaysia, the Geriatric Oral Health Assessment Index (GOHAI) has been recognized as a vital instrument for evaluating oral health-related quality of life among the elderly population. Its integration into the National Health and Morbidity Survey (NHMS) in 2018 demonstrates the country's dedication to understanding and addressing the unique oral health challenges faced by older individuals. The NHMS, led by the Ministry of Health Malaysia, serves as a crucial platform for identifying and addressing healthcare needs, while also working towards achieving sustainable development goals. This study aimed to provide valuable information for stakeholders and researchers by investigating the relationship between quality of life related to oral health and demographic factors, with the ultimate goal of enhancing oral healthcare for older individuals. Objective The objective of this research was to identify the variables that impact the Oral Health-Related Quality of Life (OHRQoL) of non-institutionalized elderly individuals who visit the Klinik Pergigian Manipal University College Malaysia (MUCM). By utilizing the OHRQoL, dental practitioners can gain insight into the elderly's oral health-related quality of life, which is crucial information for dental healthcare providers to effectively reach out to and cater to the elderly at the institution. Methodology A cross-sectional design was employed, utilizing a non-probability sampling method to select eligible elderly individuals at the clinic. A validated questionnaire comprising 18 items covering sociodemographic details and the Geriatric Oral Health Assessment Index (GOHAI) was distributed to individuals above 60 years via printed forms. One way ANOVA, unpaired t-test and multiple linear regression analysis were performed to analyze the data. Results The overall mean GOHAI score among non-institutionalized elderly attending Klinik Pergigian MUCM was 48.38±9.33, indicating poor OHRQoL. The psychosocial impact domain had a mean score of 19.33±5.21, surpassing the pain and discomfort domain with a score of 10.73±2.82, highlighting the significant impact of psychosocial factors on poor oral health-related quality of life. Multiple linear regression analysis revealed no significant associations between OHRQoL and factors such as ethnicity, living arrangements apart from spouse and family, or tertiary education among older individuals after adjusting for confounding variables. Conclusions This study indicates that sociodemographic aspects have minimal impact on the OHRQoL of seniors. Further examination is needed to understand the economic aspects of tooth replacement options and preventive measures in this age group. To enhance the OHRQoL of older adults, especially those not living in facilities like nursing homes or assisted living centers, tailored oral healthcare plans and strategies are crucial. Interdisciplinary collaboration among mental health professionals, geriatric experts, and oral healthcare providers is crucial for empowering both healthcare practitioners and seniors to maintain optimal oral health.
Fulltext Analysis of chemical compositions and larvicidal activity of nut extracts from Areca catechu Linn against Aedes (Diptera: Culicidae)

Bharathithasan M, Ravindran DR, Rajendran D, Chun SK, Abbas SA, Sugathan S, et al.

PLoS One, 2021;16(11):e0260281.
PMID: 34843539 DOI: 10.1371/journal.pone.0260281

BACKGROUND: There is a growing need to use green alternative larvicidal control for Aedes larvae compared to chemical insecticides. Substantial reliance on chemical insecticides caused insecticide resistance in mosquito populations. Thus, research for alternate chemical compounds from natural products is necessary to control Aedes larvae. This study explores the analysis of chemical compositions from Areca catechu nut as a potential larvicide for Aedes (Diptera: Culicidae).
METHODS: The Areca catechu nut collected from Ipoh, Perak, Malaysia was grounded into powder and used for Soxhlet extraction. The chemical analysis of the extracts and their structures were identified using the GCMS-QP2010 Ultra (Shimadzu) system. National Institute of Standards and Technology (NIST) Chemistry WebBook, Standard Reference Database 69 (https://webbook.nist.gov/chemistry/) and PubChem (https://pubchem.ncbi.nlm.nih.gov/), the two databases used to retrieve the synonyms, molecular formula, molecular weight, and 2-dimensional (2D) structure of chemical compounds. Next, following WHO procedures for larval bioassays, the extracts were used to asses larvicidal activity against early 4th instar larvae of Aedes aegypti and Aedes albopictus.
RESULTS: The larvicidal activities were observed against early 4th stage larvae with different concentrations in the range from 200 mg/L to 1600 mg/L. The LC50 and LC95 of Aedes aegypti were 621 mg/L and 2264 mg/L respectively; whereas the LC50 and LC95 of Aedes albopictus were 636 mg/L and 2268 mg/L respectively. Mortality was not observed in the non-target organism test. The analysis using gas chromatography and mass spectrometer recovered several chemical compounds such as Arecaidine, Dodecanoic acid, Methyl tetradecanoate, Tetradecanoic acid , and n-Hexadecanoic acid bioactive components. These chemical constituents were used as additive formulations in pesticides, pest control, insect repellent, and insecticidal agents.
CONCLUSIONS: Our study showed significant outcomes from the extract of Areca catechu nut and it deserves further investigation in relation to chemical components and larvicidal actions between different species of Aedes mosquitoes. Even though all these findings are fundamental, it may have some interesting potentials to be developed as natural bio-larvicidal products.