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Recently, wastewater-based epidemiology (WBE) research has experienced a strong impetus during the Coronavirus disease 2019 (COVID-19) pandemic. However, a few technical issues related to surveillance strategies, such as standardized procedures ranging from sampling to testing protocols, need to be resolved in preparation for future infectious disease outbreaks. This review highlights the study characteristics, potential use of WBE and overview of methods, as well as methods utilized to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) including its variant in wastewater. A literature search was performed electronically in PubMed and Scopus according to PRISMA guidelines for relevant peer-reviewed articles published between January 2020 and March 2022. The search identified 588 articles, out of which 221 fulfilled the necessary criteria and are discussed in this review. Most global WBE studies were conducted in North America (n = 75, 34 %), followed by Europe (n = 68, 30.8 %), and Asia (n = 43, 19.5 %). The review also showed that most of the application of WBE observed were to correlate SARS-CoV-2 ribonucleic acid (RNA) trends in sewage with epidemiological data (n = 90, 40.7 %). The techniques that were often used globally for sample collection, concentration, preferred matrix recovery control and various sample types were also discussed. Overall, this review provided a framework for researchers specializing in WBE to apply strategic approaches to their research questions in achieving better functional insights. In addition, areas that needed more in-depth analysis, data collection, and ideas for new initiatives were identified.
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Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may transmit through airborne route particularly when the aerosol particles remain in enclosed spaces with inadequate ventilation. There has been no standard recommended method of determining the virus in air due to limitations in pre-analytical and technical aspects. Furthermore, the presence of low virus loads in air samples could result in false negatives. Our study aims to explore the feasibility of detecting SARS-CoV-2 ribonucleic acid (RNA) in air samples using droplet digital polymerase chain reaction (ddPCR). Active and passive air sampling was conducted between December 2021 and February 2022 with the presence of COVID-19 confirmed cases in two hospitals and a quarantine center in Klang Valley, Malaysia. SARS-CoV-2 RNA in air was detected and quantified using ddPCR and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The comparability of two different digital PCR platforms (QX200 and QIAcuity) to RT-PCR were also investigated. Additionally negative staining transmission electron microscopy was performed to visualize virus ultrastructure. Detection rates of SARS-CoV-2 in air samples using ddPCR were higher compared to RT-PCR, which were 15.2% (22/145) and 3.4% (5/145), respectively. The sensitivity and specificity of ddPCR was 100 and 87%, respectively. After excluding 17 negative samples (50%) by both QX200 and QIAcuity, 15% samples (5/34) were found to be positive both ddPCR and dPCR. There were 23.5% (8/34) samples that were detected positive by ddPCR but negative by dPCR. In contrast, there were 11.7% (4/34) samples that were detected positive by dPCR but negative by ddPCR. The SARS-CoV-2 detection method by ddPCR is precise and has a high sensitivity for viral RNA detection. It could provide advances in determining low viral titter in air samples to reduce false negative reports, which could complement detection by RT-PCR.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , RNA Viral/análise , Carga Viral/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Teste para COVID-19RESUMO
Contamination of water systems with endocrine disrupting chemicals (EDCs) is becoming a major public health concern due to their toxicity and ubiquity. The intrusion of EDCs into water sources and drinking water has been associated with various adverse health effects on humans. However, there is no comprehensive overview of the occurrence of EDCs in Malaysia's water systems. This report aims to describe the occurrence of EDCs and their locations. Literature search was conducted electronically in two databases (PubMed and Scopus). A total of 41 peer-reviewed articles published between January 2000 and May 2021 were selected. Most of the articles dealt with pharmaceuticals (16), followed by pesticides (7), hormones (7), mixed compounds (7), and plasticisers (4). Most studies (40/41) were conducted in Peninsular Malaysia, with 60.9% in the central region and almost half (48.8%) in the Selangor State. Only one study was conducted in the northern region and East Malaysia. The Langat River, the Klang River, and the Selangor River were among the most frequently studied EDC-contaminated surface waters, while the Pahang River and the Skudai River had the highest concentrations of some of the listed compounds. Most of the risk assessments resulted in a hazard quotient (HQ) and a risk quotient (RQ) < 1, indicating negligible health risk, except for ciprofloxacin and dexamethasone, which had a potential human health risk (HQHH) > 1 in the Selangor River. An RQ > 1 for combined pharmaceuticals was found in Putrajaya tap water. Overall, this work provides a comprehensive overview of the occurrence of EDCs in Malaysia's water systems. The findings from this review can be used to mitigate risks and strengthen legislation and policies for safer drinking water.
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Água Potável , Disruptores Endócrinos , Poluentes Químicos da Água , Humanos , Poluentes Químicos da Água/análise , Disruptores Endócrinos/análise , Malásia , Monitoramento Ambiental/métodos , Rios/química , Preparações FarmacêuticasRESUMO
One of the most significant and difficult jobs in food sustainability, is to make use of waste in the vegetable and fruit processing sectors. The discarded fruits along with their waste materials, is anticipated to have potential use for further industrial purposes via extraction of functional ingredients, extraction of bioactive components, fermentation. As a result of its abundant availability, simplicity and safe handling, and biodegradability, pineapple waste is now the subject of extensive research. It is regarded as a resource for economic development. This vast agro-industrial waste is being investigated as a low-cost raw material to produce a variety of high-value-added goods. Researchers have concentrated on the exploitation of pineapple waste, particularly for the extraction of prebiotic oligosaccharides as well as bromelain enzyme, and as a low-cost source of fibre, biogas, organic acids, phenolic antioxidants, and ethanol. Thus, this review emphasizes on pineapple waste valorisation approaches, extraction of bioactive and functional ingredients together with the advantages of pineapple waste to be used in many areas. From the socioeconomic perspective, pineapple waste can be a new raw material source to the industries and may potentially replace the current expensive and non-renewable sources. This review summarizes various approaches used for pineapple waste processing along with several important value-added products gained which could contribute towards healthy food and a sustainable environment.
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Ananas , Antioxidantes , Biotecnologia , Frutas , ResíduosRESUMO
Enzyme hydrolysis faces a bottleneck due to the recalcitrance of the lignocellulose biomass. The protein engineering of GH11 xylanase from Aspergillus fumigatus RT-1 was performed near the active site and at the N-terminal region to improve its catalytic efficiency towards pretreated kenaf (Hibiscus cannabinus) hydrolysis. Five mutants were constructed by combined approaches of error-prone PCR, site-saturation and site-directed mutagenesis. The double mutant c168â¯t/Q192H showed the most effective hydrolysis reaction with a 13.9-fold increase in catalytic efficiency, followed by mutants Y7L and c168â¯t/Q192â¯H/Y7L with a 1.6-fold increase, respectively. The enhanced catalytic efficiency evoked an increase in sugar yield of up to 28% from pretreated kenaf. In addition, mutant c168â¯t/Q192â¯H/Y7L improved the thermostability at higher temperature and acid stability. This finding shows that mutations at distances less than 15â¯Å from the active site and at putative secondary binding sites affect xylanase catalytic efficiency towards insoluble substrates hydrolysis.
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Aspergillus fumigatus/enzimologia , Hibiscus/metabolismo , Engenharia de Proteínas , Xilosidases/genética , Xilosidases/metabolismo , Biomassa , Domínio Catalítico , Hidrólise , Mutagênese , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismoRESUMO
At childbirth (parturition), zinc (Zn) homeostasis in cord blood (CB) can be affected by a number of factors: Zn in maternal blood, parturition related stress as well as metallothionein (MT). Both Zn and stress are known inducers of MT which is primarily involved in Zn homeostasis. This study analyzed Zn concentration [Zn], in CB components and MT-2A transcription in CB mononuclear cells (MNC) in relation to primiparous and multiparous childbirth. [Zn] in CB (n = 47) plasma, erythrocytes, and MNCs were measured by atomic absorption spectrophotometry (λ = 213.9 nm). The MT-2A transcription in CB-MNC was quantified using real-time PCR. Significant correlations (Pearson r) were found between: plasma-[Zn] and erythrocyte-[Zn] (p = 0.002); [Zn] and MT-2A messenger RNA (mRNA) (p = 0.000) in CB-MNC. Student's t tests showed higher levels of MT-2A mRNA and MNC-[Zn] in CB of older (≥25 years) compared to younger mothers (≤24 years) (p = 0.043 and p = 0.016, respectively). Significantly higher [Zn] was found in CB plasma (p = 0.017) and MNC (p = 0.041) of older primiparous compared to the younger primiparous and older multiparous mothers respectively. MT-2A mRNA in CB-MNC was significantly lower in CB of younger primiparous mothers compared to their older counterparts (p = 0.001). Path analysis showed that MNC-[Zn] (ß = 0.83; p = 0.000) had a greater influence on MT-2A mRNA expression, compared to parity (ß = -0.14; p = 0.033). Higher [Zn] in CB of primiparous mothers could be linked to higher stress during parturition, however, might be beneficial for the growth and development of the child. Together MNC-[Zn] and parity contributed ~70 % of the MT-2A transcription in CB-MNC.