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Sustainable landfill leachate treatment: Optimize use of guar gum as natural coagulant and floc characterization

Cheng SY, Show PL, Juan JC, Ling TC, Lau BF, Lai SH, et al.

Environ Res, 2020 09;188:109737.
PMID: 32554270 DOI: 10.1016/j.envres.2020.109737

Sustainable wastewater treatment necessitates the application of natural and green material in the approach. Thus, selecting a natural coagulant in leachate treatment is a crucial step in landfill operation to prevent secondary environmental pollution due to residual inorganic coagulant in treated effluent. Current study investigated the application of guar gum in landfill leachate treatment. Central composite design in response surface methodology was used to optimize the performance of Chemical Oxygen Demand (COD) removal. Quadratic model developed indicated the optimum COD removal 22.57% at guar gum dosage of 44.39 mg/L, pH 8.56 (natural pH of leachate) and mixing speed 79.27 rpm. Scanning electron microscopy showed that floc was compact and energy-dispersive-x-ray analysis showed that guar gum was capable to adsorb multiple ions from the leachate. Structural characterization using Fourier Transform Infrared analysis demonstrated that hydrogen bonding between guar and pollutant particles was involved in coagulation and flocculation process. Therefore, guar gum coagulant present potential to be an alternative in leachate treatment where pH requirement is not required during treatment. Simultaneously, adsorption by guar gum offers added pollutant removal advantage.
Gelatine Film Incorporated with Clitoria ternatea-Derived Anthocyanin Microcapsules, A Food Packaging Material Effective Against Foodborne Pathogens

Leong CR, Daud NS, Tong WY, Cheng SY, Tan WN, Hamin NS, et al.

Food Technol Biotechnol, 2021 Dec;59(4):422-431.
PMID: 35136367 DOI: 10.17113/ftb.59.04.21.7069

Research background: Microbial contamination of food products is one of the significant causes of food spoilage and foodborne illnesses. The use of active packaging films incorporated with antimicrobial agents can be a measure to improve food quality and extend shelf life. Nevertheless, antimicrobial agents such as silver, copper, titanium and zinc in the packaging films have raised concerns among consumers due to toxicity issues.
Experimental approach: The current study aims to develop biodegradable gelatine-based edible films incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. The impact of incorporation of microcapsules with anthocyanins on the morphology, thermal, mechanical, water vapour barrier and physicochemical properties of the gelatine films was evaluated in this study. The effectiveness of the developed films against foodborne pathogens and their application for perishable food protection were also investigated.
Results and conclusions: The results show that incorporating anthocyanin microcapsules enhances the gelatine film physical and mechanical properties by increasing the thickness, tensile strength, Young's modulus and elongation at break of the films. Scanning electronic microscopy analysis revealed that the film surface morphology with anthocyanin microcapsules had a homogeneous and smooth surface texture compared to the control. The thermogravimetric analysis also showed a slight improvement in the thermal properties of the developed films. Agar well diffusion assay revealed that the developed films exhibit significant inhibition against a broad-spectrum of bacteria. Furthermore, the films composed of gelatine with anthocyanin microcapsules significantly reduced the total viable count of microorganisms in the bean curd during storage for 12 days compared with the control films.
Novelty and scientific contribution: Increasing global awareness of healthy and safe food with minimal synthetic ingredients as preservatives has sparked the search for the use of antimicrobial agents of natural origins in active food packaging material. In this study, a safe and effective active packaging film was developed using an environmentally friendly biopolymer, gelatine film incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. This study demonstrated that such a method is not only able to improve the film physical properties but can also significantly prolong the shelf life of food products by protecting them from microbial spoilage.
New Prospects for Modified Algae in Heavy Metal Adsorption

Cheng SY, Show PL, Lau BF, Chang JS, Ling TC

Trends Biotechnol, 2019 Nov;37(11):1255-1268.
PMID: 31174882 DOI: 10.1016/j.tibtech.2019.04.007

Heavy metal pollution is one of the most pervasive environmental problems globally. Novel finely tuned algae have been proposed as a means to improve the efficacy and selectivity of heavy metal biosorption. This article reviews current research on selective algal heavy metal adsorption and critically discusses the performance of novel biosorbents. We emphasize emerging state-of-the-art techniques that customize algae for enhanced performance and selectivity, particularly molecular and chemical extraction techniques as well as nanoparticle (NP) synthesis approaches. The mechanisms and processes for developing novel algal biosorbents are also presented. Finally, we discuss the applications, challenges, and future prospects for modified algae in heavy metal biosorption.
Landfill leachate wastewater treatment to facilitate resource recovery by a coagulation-flocculation process via hydrogen bond

Cheng SY, Show PL, Juan JC, Chang JS, Lau BF, Lai SH, et al.

Chemosphere, 2021 Jan;262:127829.
PMID: 32768754 DOI: 10.1016/j.chemosphere.2020.127829

Recent trend to recover value-added products from wastewater calls for more effective pre-treatment technology. Conventional landfill leachate treatment is often complex and thus causes negative environmental impacts and financial burden. In order to facilitate downstream processing of leachate wastewater for production of energy or value-added products, it is pertinent to maximize leachate treatment performance by using simple yet effective technology that removes pollutants with minimum chemical added into the wastewater that could potentially affect downstream processing. Hence, the optimization of coagulation-flocculation leachate treatment using multivariate approach is crucial. Central composite design was applied to optimize operating parameters viz. Alum dosage, pH and mixing speed. Quadratic model indicated that the optimum COD removal of 54% is achieved with low alum dosage, pH and mixing speed of 750 mgL-1, 8.5 and 100 rpm, respectively. Optimization result showed that natural pH of the mature landfill leachate sample is optimum for alum coagulation process. Hence, the cost of pH adjustment could be reduced for industrial application by adopting optimized parameters. The inherent mechanism of pollutant removal was elucidated by FTIR peaks at 3853 cm-1 which indicated that hydrogen bonds play a major role in leachate removal by forming well aggregated flocs. This is concordance with SEM image that the floc was well aggregated with the porous linkages and amorphous surface structure. The optimization of leachate treatment has been achieved by minimizing the usage of alum under optimized condition.
Phomopsidione nanoparticles coated contact lenses reduce microbial keratitis causing pathogens

Bin Sahadan MY, Tong WY, Tan WN, Leong CR, Bin Misri MN, Chan M, et al.

Exp Eye Res, 2019 01;178:10-14.
PMID: 30243569 DOI: 10.1016/j.exer.2018.09.011

Microbial keratitis is the infection caused by pathogenic microorganisms that commonly occurs among the contact lens users. Various antimicrobial compounds were coated on contact lenses to kill keratitis causing microorganisms, however these compounds caused several adverse side effects. Hence, the aim of this study is to develop a silicone hydrogel contact lens coated with phomopsidione nanoparticle that inhibit keratitis causing clinical isolates. Phomopsidione nanoparticles were synthesized using polyvinyl alcohol as encapsulant. The nanoparticles showed an average size of 77.45 nm, with neutral surface charge. Two drug release patterns were observed in the drug release profile, which are the initial slow release phase with extended drug release (release rate 46.65 μg/h), and the burst release phase observed on Day 2 (release rate 2224.49 μg/h). This well-regulated drug delivery system enables the control of drug release to meet the therapeutic requirements. On agar diffusion assay, 3 out of 5 test microorganisms were inhibited by phomopsidione nanoparticle coated contact lenses, including two Gram negative bacteria. Besides, all test microorganisms showed at least 99% of growth reduction, with the treatment of the contact lens model. The drug loaded onto the nanoparticles is sufficient to prevent the bacterial growth. In conclusion, this study provides an effective alternative to combat keratitis-causing microorganisms among contact wearers.
Palliative care development in the Asia-Pacific region: an international survey from the Asia Pacific Hospice Palliative Care Network (APHN)

Yamaguchi T, Kuriya M, Morita T, Agar M, Choi YS, Goh C, et al.

BMJ Support Palliat Care, 2017 Mar;7(1):23-31.
PMID: 25012126 DOI: 10.1136/bmjspcare-2013-000588

BACKGROUND: Although palliative care is an important public healthcare issue worldwide, the current situation in the Asia-Pacific region has not been systematically evaluated.
OBJECTIVES: This survey aimed to clarify the current status of palliative care in the Asia-Pacific region.
METHODS: Questionnaires were sent to a representative physician of each member country/region of the Asia Pacific Hospice Palliative Care Network (APHN). The questionnaire examined palliative care service provision, information regarding physician certification in palliative care, the availability of essential drugs for palliative care listed by the International Association for Hospice and Palliative Care (IAHPC) and the regulation of opioid-prescribing practice.
RESULTS: Of the 14 member countries/regions of the APHN, 12 (86%) responded. Some form of specialist palliative care services had developed in all the responding countries/regions. Eight member countries/regions had physician certifications for palliative care. Most essential drugs for palliative care listed by the IAHPC were available, whereas hydromorphone, oxycodone and transmucosal fentanyl were unavailable in most countries/regions. Six member countries/regions required permission to prescribe and receive opioids.
CONCLUSIONS: The development of palliative care is in different stages across the surveyed countries/regions in the Asia-Pacific region. Data from this survey can be used as baseline data for monitoring the development of palliative care in this region.
Global 30-day morbidity and mortality of surgery for perforated peptic ulcer: GRACE study

Abouelazayem M, Jain R, Wilson MSJ, Martinino A, Balasubaramaniam V, Biffl W, et al.

Surg Endosc, 2024 Aug;38(8):4402-4414.
PMID: 38886232 DOI: 10.1007/s00464-024-10881-0

BACKGROUND: There is little international data on morbidity and mortality of surgery for perforated peptic ulcer (PPU). This study aimed to understand the global 30-day morbidity and mortality of patients undergoing surgery for PPU and to identify variables associated with these.
METHOD: We performed an international study of adults (≥ 18 years) who underwent surgery for PPU from 1st January 2022 to 30th June 2022. Patients who were treated conservatively or had an underlying gastric cancer were excluded. Patients were divided into subgroups according to age (≤ 50 and > 50 years) and time from onset of symptoms to hospital presentation (≤ 24 and > 24 h). Univariate and Multivariate analyses were carried out to identify factors associated with higher 30-day morbidity and mortality.
RESULTS: 1874 patients from 159 centres across 52 countries were included. 78.3% (n = 1467) of the patients were males and the median (IQR) age was 49 years (25). Thirty-day morbidity and mortality were 48.5% (n = 910) and 9.3% (n = 174) respectively. Median (IQR) hospital stay was 7 (5) days. Open surgery was performed in 80% (n = 1505) of the cohort. Age > 50 years [(OR = 1.7, 95% CI 1.4-2), (OR = 4.7, 95% CI 3.1-7.6)], female gender [(OR = 1.8, 95% CI 1.4-2.3), (OR = 1.9, 95% CI 1.3-2.9)], shock on admission [(OR = 2.1, 95% CI 1.7-2.7), (OR = 4.8, 95% CI 3.2-7.1)], and acute kidney injury [(OR = 2.5, 95% CI 1.9-3.2), (OR = 3.9), 95% CI 2.7-5.6)] were associated with both 30-day morbidity and mortality. Delayed presentation was associated with 30-day morbidity [OR = 1.3, 95% CI 1.1-1.6], but not mortality.
CONCLUSIONS: This study showed that surgery for PPU was associated with high 30-day morbidity and mortality rate. Age, female gender, and signs of shock at presentation were associated with both 30-day morbidity and mortality.
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

Klionsky DJ, Abdel-Aziz AK, Abdelfatah S, Abdellatif M, Abdoli A, Abel S, et al.

Autophagy, 2021 Jan;17(1):1-382.
PMID: 33634751 DOI: 10.1080/15548627.2020.1797280

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.