MyMedR

Displaying publications 81 - 100 of 2877 in total

Abstract:

Sort:

High pressure CO2 adsorption onto Malaysian Mukah-Balingian coals: Adsorption isotherms, thermodynamic and kinetic investigations

Abunowara M, Bustam MA, Sufian S, Babar M, Eldemerdash U, Mukhtar A, et al.

Environ Res, 2023 Feb 01;218:114905.
PMID: 36442522 DOI: 10.1016/j.envres.2022.114905

CO2 sequestration into coalbed seams is one of the practical routes for mitigating CO2 emissions. The adsorption mechanisms of CO2 onto Malaysian coals, however, are not yet investigated. In this research CO2 adsorption isotherms were first performed on dry and wet Mukah-Balingian coal samples at temperatures ranging from 300 to 348 K and pressures up to 6 MPa using volumetric technique. The dry S1 coal showed the highest CO2 adsorption capacity of 1.3 mmol g-1, at 300 K and 6 MPa among the other coal samples. The experimental results of CO2 adsorption were investigated using adsorption isotherms, thermodynamics, and kinetic models. Nonlinear analysis has been employed to investigate the data of CO2 adsorption onto coal samples via three parameter isotherm equilibrium models, namely Redlich Peterson, Koble Corrigan, Toth, Sips, and Hill, and four parameter equilibrium model, namely Jensen Seaton. The results of adsorption isotherm suggested that the Jensen Seaton model described the experimental data well. Gibb's free energy change values are negative, suggesting that CO2 adsorption onto the coal occurred randomly. Enthalpy change values in the negative range established that CO2 adsorption onto coal is an exothermic mechanism. Webber's pore-diffusion model, in particular, demonstrated that pore-diffusion was the main controlling stage in CO2 adsorption onto coal matrix. The activation energy of the coals was calculated to be below -13 kJ mol-1, indicating that adsorption of CO2 onto coals occurred through physisorption. The results demonstrate that CO2 adsorption onto coal matrix is favorable, spontaneous, and the adsorbed CO2 molecules accumulate more onto coal matrix. The observations of this investigation have significant implications for a more accurate measurement of CO2 injection into Malaysian coalbed seams.

Matched MeSH terms: Temperature
Multi-objective operation optimization of spent coffee ground torrefaction for carbon-neutral biochar production

Chen WH, Lee KT, Ho KY, Culaba AB, Ashokkumar V, Juan CJ

Bioresour Technol, 2023 Feb;370:128584.
PMID: 36610482 DOI: 10.1016/j.biortech.2023.128584

Many energy-intensive processes are employed to enhance biomass fuel properties to overcome the difficulties in utilizing biomass as fuel. Therefore, energy conservation during these processes is crucial for realizing a circular bioeconomy. This study develops a newly devised method to evaluate SCG biochars' higher heating value (HHV) and predict moisture content from power consumption. It is found that the increasing rates of HHV immediately follow decreases in power consumption, which could be used to determine the pretreatment time for energy conservation. The non-dominated sorting genetic algorithm II (NSGA-II) maximizes SCG biochar's HHV while minimizing energy consumption. The results show that producing SCG biochar with 23.98 MJ∙kg-1 HHV requires 20.042 MJ∙kg-1, using a torrefaction temperature of 244 °C and torrefaction time of 27 min and 43 sec. Every kilogram of biochar with an energy yield of 85.93 % is estimated to cost NT$ 12.21.

Matched MeSH terms: Temperature
A study to examine the ageing behaviour of cold plasma-treated agricultural seeds

Ahmed N, Siow KS, Wee MFMR, Patra A

Sci Rep, 2023 Jan 30;13(1):1675.
PMID: 36717647 DOI: 10.1038/s41598-023-28811-w

Cold plasma (low pressure) technology has been effectively used to boost the germination and growth of various crops in recent decades. The durability of these plasma-treated seeds is essential because of the need to store and distribute the seeds at different locations. However, these ageing effects are often not ascertained and reported because germination and related tests are carried out within a short time after the plasma-treatment. This research aims to fill that knowledge gap by subjecting three different types of seeds (and precursors): Bambara groundnuts (water), chilli (oxygen), and papaya (oxygen) to cold plasma-treatment. Common mechanisms found for these diverse seed types and treatment conditions were the physical and chemical changes induced by the physical etching and the cold plasma on the seeds and subsequent oxidation, which promoted germination and growth. The high glass transition temperature of the lignin-cellulose prevented any physical restructuring of the surfaces while maintaining the chemical changes to continue to promote the seeds germination and growth. These changes were monitored over 60 days of ageing using water contact angle (WCA), water uptake, electrical conductivity, field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The vacuum effect was also investigated to separate its effect from cold plasma (low pressure). This finding offers a framework for determining how long agricultural seeds that have received plasma treatment can be used. Additionally, there is a need to transfer this research from the lab to the field. Once the impact of plasma treatment on seeds has been estimated, it will be simple to do so.

Matched MeSH terms: Cold Temperature
Fulltext Evidence of adult male scarcity associated with female-skewed offspring sex ratios in sea turtles

Hays GC, Laloë JO, Lee PLM, Schofield G

Curr Biol, 2023 Jan 09;33(1):R14-R15.
PMID: 36626854 DOI: 10.1016/j.cub.2022.11.035

Climate change is a clear and present threat to species survival. For species with temperature-dependent sex determination, including all sea turtles, it has been hypothesised that climate change may drive the creation of sex-ratio biases leading to population extinctions1. Through a global analysis across multiple species, we present the first direct empirical evidence for a demographic consequence of male scarcity in sea turtle populations, with a lower incidence of multiple paternity being found in populations with more extreme female-biased hatchling sex-ratio skews. For green turtles, when the female bias in hatchling sex ratio was >90%, the incidence of multiple paternity was low compared to other nesting sites, being 24.5% in the eastern Mediterranean (Cyprus), 36.4% on Redang Island (Malaysia) and 15.4% on the southern Great Barrier Reef (Heron Island, Australia) compared to higher values (range 61.1-91.7%) at other sites globally. These results suggest that a low incidence of multiple paternity may serve as a harbinger of future problems with egg fertility if males become even scarcer. Assessments of the incidence of multiple paternity at sites where adult males are expected to become scarce, such as Raine Island on the northern Great Barrier Reef in Australia, may help to identify when a lack of males raises the threat of local extinctions. In such cases, intervention to increase the production of male hatchlings may be needed.

Matched MeSH terms: Temperature
Evaluation of membrane fouling at elevated temperature impacted by algal organic matter

Ng YS, Ragupathy S, Shau Hwai AT, Khoo KS, Chieh Chan DJ

Chemosphere, 2023 Jan;310:136790.
PMID: 36220430 DOI: 10.1016/j.chemosphere.2022.136790

Membrane distillation (MD) is a thermally driven technology applied in desalination and water reuse with utilisation of sustainable energy. However, algal organic matter (AOM) could foul membrane critically and plague MD's long-term operational stability. In this study, the soluble extracellular polymeric substance (sEPS) and intracellular organic matter with bound extracellular polymeric substance (IOM + bEPS) of two algal species (Amphora coffeaeformis and Navicula incerta) were exposed to 60 °C, 70 °C and 80 °C for 8 h with polypropylene hydrophobic membrane, simulating heated AOMs contacted with membrane inside MD unit, to study the temperature effect on membrane fouling. The dissolved carbohydrate and protein in the sEPS and IOM + bEPS samples generally increased after being heated. Heating caused cell lysis and the release and dissolution of carbohydrate and protein from sEPS, IOM and bEPS into water. As heating temperature increased, the carbohydrate release from the AOM usually increased. The contact angle of membrane contacted with sEPS and IOM + bEPS reduced significantly after heat treatment. The reduction in IOM + bEPS was larger than sEPS, in line with SEM analysis, indicating membrane surfaces and pores with IOM + bEPS fouled more severely than sEPS. It is due to higher hydrophobicity in IOM + bEPS causing adherence to membrane and presence of amphiphiles. High protein, lipid, and saturated fats proportions also cause severe fouling. SEM-EDX analysis indicated presence of O, Na, Cl and Mg elements, pointing to carbohydrate and lipids, and salt trapped in foulants. AOM heating and composition had direct effect to the membrane integrity, dictating severity of fouling in MD operations.

Matched MeSH terms: Temperature
Carbonized rice husk coated solar absorber for clean water generation from seawater with a solar still

Karen WMJ, Wong CY, Wang Z, Liew WYH, Melvin GJH

Environ Technol, 2023 Jan;44(3):326-333.
PMID: 34407722 DOI: 10.1080/09593330.2021.1970820

This study demonstrated the generation of clean water from seawater collected at the beach coast in Universiti Malaysia Sabah, Malaysia, with carbonized rice husk coated melamine sponge as solar absorber by a solar still. Melamine sponge was utilized as a seawater transportation medium since its porous structure is excellent in channelling the seawater. Whereas carbonized rice husk was used as the photothermal conversion material for its efficient heat absorption due to its black colour and porous structure. Implementing air gap between the seawater body and solar absorber, and restricted water pathway assisted in localizing heat on the top surface of the solar absorber. Clean water was generated under direct solar radiation during the day at an open space with average solar intensity around 1.1∼1.2 kW/m2 (slightly higher than 1 sun) for about 4 h. Efficiency of the solar absorber was calculated, while the quality of the generated clean water was observed in terms of salinity and pH value. Insulated solar still with carbon-coated sponge showed the highest efficiency at about 54.74%. Salinity of the collected clean water significantly reduced to consumable level which was approximately 55 ppm, and the pH value at about 6.73 where it was within the safe limit of the drinkable water pH.

Matched MeSH terms: Hot Temperature
Thermo-Responsive Polymer-siRNA Conjugates Enabling Artificial Control of Gene Silencing around Body Temperature

Honda Y, Onodera S, Takemoto H, Harun NFC, Nomoto T, Matsui M, et al.

Pharm Res, 2023 Jan;40(1):157-165.
PMID: 36307662 DOI: 10.1007/s11095-022-03414-8

PURPOSE: Controlling small interfering RNA (siRNA) activity by external stimuli is useful to exert a selective therapeutic effect at the target site. This study aims to develop a technology to control siRNA activity in a thermo-responsive manner, which can be utilized even at temperatures close to body temperature.
METHODS: siRNA was conjugated with a thermo-responsive copolymer that was synthesized by copolymerization of N-isopropylacrylamide (NIPAAm) and hydrophilic N,N-dimethylacrylamide (DMAA) to permit thermally controlled interaction between siRNA and an intracellular gene silencing-related protein by utilizing the coil-to-globule phase transition of the copolymer. The composition of the copolymer was fine-tuned to obtain lower critical solution temperature (LCST) around body temperature, and the phase transition behavior was evaluated. The cellular uptake and gene silencing efficiency of the copolymer-siRNA conjugates were then investigated in cultured cells.
RESULTS: The siRNA conjugated with the copolymer with LCST of 38.0°C exhibited ~ 11.5 nm of the hydrodynamic diameter at 37°C and ~ 9.8 nm of the diameter at 41°C, indicating the coil-globule transition above the LCST. In line with this LCST behavior, its cellular uptake and gene silencing efficiency were enhanced when the temperature was increased from 37°C to 41°C.
CONCLUSION: By fine-tuning the LCST behavior of the copolymer that was conjugated with siRNA, siRNA activity could be controlled in a thermo-responsive manner around the body temperature. This technique may offer a promising approach to induce therapeutic effects of siRNA selectively in the target site even in the in vivo conditions.

Matched MeSH terms: Body Temperature*; Temperature
Fabrication and response optimization of Moringa oleifera-functionalized nanosorbents for the removal of diesel range organics from contaminated water

Ubah PC, Dashti AF, Saaid M, Imam SS, Adnan R

Environ Sci Pollut Res Int, 2023 Jan;30(2):4462-4484.
PMID: 35969341 DOI: 10.1007/s11356-022-22245-z

The purpose of this research is to synthesize environmentally friendly nanosorbents for the novel adsorption of diesel range organics (DRO) from contaminated water. Central composite design (CCD) analysis of response surface methodology (RSM) was employed in a model fitting of the variables predicting the adsorption efficiency of Moringa oleifera-functionalized zerovalent iron particles (ZINPs) for the removal of DRO. The effects of the reaction parameters on the response were screened using 24 factorial designs to determine the statistically significant independent variables. A quadratic model predicting the DRO adsorption efficiency of ZINPs with an F value of 276.84 (p value

Matched MeSH terms: Temperature
Intensification of Inclusion Body Processing via Temperature-Based Refolding

Wong RS, Alias NNM, Ong EBB, Liew MWO

Methods Mol Biol, 2023;2617:189-200.
PMID: 36656525 DOI: 10.1007/978-1-0716-2930-7_13

Inclusion bodies (IB) are dense insoluble aggregates of mostly misfolded polypeptides that usually result from recombinant protein overexpression. IB formation has been observed in protein expression systems such as E. coli, yeast, and higher eukaryotes. To recover soluble recombinant proteins in their native state, IB are commonly first solubilized with a high concentration of denaturant. This is followed by concurrent denaturant removal or reduction and a transition into a refolding-favorable chemical environment to facilitate the refolding of solubilized protein to its native state. Due to the high concentration of denaturant used, conventional refolding approaches can result in dilute products and are buffer inefficient. To circumvent the limitations of conventional refolding approaches, a temperature-based refolding approach which combines a low concentration of denaturant (0.5 M guanidine hydrochloride, GdnHCl) with a high temperature (95 °C) during solubilization was proposed. In this chapter, we describe a temperature-based refolding approach for the recovery of core streptavidin (cSAV) from IB. Through the temperature-based approach, intensification was achieved through the elimination of a concentration step which would be required by a dilution approach and through a reduction in buffer volumes required for dilution or denaturant removal. High-temperature treatment during solubilization may have also resulted in the denaturation and aggregation of undesired host-cell proteins, which could then be removed through a centrifugation step resulting in refolded cSAV of high purity without the need for column purification. Refolded cSAV was characterized by biotin-binding assay and SDS-PAGE, while purity was determined by RP-HPLC.

Matched MeSH terms: Hot Temperature*; Temperature
Fulltext Investigation of the impacts of climate change and rising temperature on food poisoning cases in Malaysia

Hassan NA, Hashim JH, Wan Puteh SE, Wan Mahiyuddin WR, Mohd MSF, Shaharudin SM, et al.

PLoS One, 2023;18(10):e0283133.
PMID: 37862373 DOI: 10.1371/journal.pone.0283133

This study is an attempt to investigate climate-induced increases in morbidity rates of food poisoning cases. Monthly food poisoning cases, average monthly meteorological data, and population data from 2004 to 2014 were obtained from the Malaysian Ministry of Health, Malaysian Meteorological Department, and Department of Statistics Malaysia, respectively. Poisson generalised linear models were developed to assess the association between climatic parameters and the number of reported food poisoning cases. The findings revealed that the food poisoning incidence in Malaysia during the 11 years study period was 561 cases per 100 000 population for the whole country. Among the cases, females and the ethnic Malays most frequently experienced food poisoning with incidence rates of 313 cases per 100,000 and 438 cases per 100,000 population over the period of 11 years, respectively. Most of the cases occurred within the active age of 13 to 35 years old. Temperature gave a significant impact on the incidence of food poisoning cases in Selangor (95% CI: 1.033-1.479; p = 0.020), Melaka (95% CI: 1.046-2.080; p = 0.027), Kelantan (95% CI: 1.129-1.958; p = 0.005), and Sabah (95% CI: 1.127-2.690; p = 0.012) while rainfall was a protective factor in Terengganu (95% CI: 0.996-0.999; p = 0.034) at lag 0 month. For a 1.0°C increase in temperature, the excess risk of food poisoning in each state can increase up to 74.1%, whereas for every 50 mm increase in rainfall, the risk of getting food poisoning decreased by almost 10%. The study concludes that climate does affect the distribution of food poisoning cases in Selangor, Melaka, Kelantan, Sabah, and Terengganu. Food poisoning cases in other states are not directly associated with temperature but related to monthly trends and seasonality.

Matched MeSH terms: Temperature
Fulltext Hydrogen gas sensing performance of a carbon-doped boron nitride nanoribbon at elevated temperatures

Taib AK, Johari Z, Abd Rahman SF, Mohd Yusoff MF, Hamzah A

PLoS One, 2023;18(3):e0282370.
PMID: 36897883 DOI: 10.1371/journal.pone.0282370

In this study, computational simulations were used to investigate the performance of a carbon-doped boron nitride nanoribbon (BC2NNR) for hydrogen (H2) gas sensing at elevated temperatures. The adsorption energy and charge transfer were calculated when H2 was simultaneously attached to carbon, boron, and both boron and nitrogen atoms. The sensing ability was further analyzed considering the variations in current-voltage (I-V) characteristics. The simulation results indicated that the energy bandgap of H2 on carbon, boron, and both boron and nitrogen exhibited a marginal effect during temperature variations. However, significant differences were observed in terms of adsorption energy at a temperature of 500 K, wherein the adsorption energy was increased by 99.62% of that observed at 298 K. Additionally, the evaluation of charge transfer indicated that the strongest binding site was achieved at high adsorption energies with high charge transfers. Analysis of the I-V characteristics verified that the currents were considerably affected, particularly when a certain concentration of H2 molecules was added at the highest sensitivity of 15.02% with a bias voltage of 3 V. The sensitivity at 298 K was lower than those observed at 500 and 1000 K. The study findings can form the basis for further experimental investigations on BC2NNR as a hydrogen sensor.

Matched MeSH terms: Temperature
Superheated steam processing: An emerging technology to improve food quality and safety

Fang J, Liu C, Law CL, Mujumdar AS, Xiao HW, Zhang C

Crit Rev Food Sci Nutr, 2023;63(27):8720-8736.
PMID: 35389273 DOI: 10.1080/10408398.2022.2059440

Heat processing is one of the most efficient strategies used in food industry to improve quality and prolong shelf life. However, conventional processing methods such as microwave heating, burning charcoal treatment, boiling, and frying are energy-inefficient and often lead to inferior product quality. Superheated steam (SHS) is an innovative technology that offers many potential benefits to industry and is increasingly used in food industry. Compared to conventional processing methods, SHS holds higher heat transfer coefficients, which can reduce microorganisms on surface of foodstuffs efficiently. Additionally, SHS generates a low oxygen environment, which prevents lipid oxidation and harmful compounds generation. Furthermore, SHS can facilitate development of desired product quality, such as protein denaturation with functional characteristics, proper starch gelatinization, and can also reduce nutrient loss, and improve the physicochemical properties of foodstuffs. The current work provides a comprehensive review of the impact of SHS on the nutritional, physicochemical, and safety properties of various foodstuffs including meat, fruits, and vegetables, cereals, etc. Additionally, it also provides food manufacturers and researchers with basic knowledge and practical techniques for SHS processing of foodstuffs, which may improve the current scope of SHS and transfer current food systems to a healthy and sustainable one.

Matched MeSH terms: Hot Temperature
Fulltext Temperature vegetation dryness index (TVDI) for drought monitoring in the Guangdong Province from 2000 to 2019

Chen A, Jiang J, Luo Y, Zhang G, Hu B, Wang X, et al.

PeerJ, 2023;11:e16337.
PMID: 38130929 DOI: 10.7717/peerj.16337

Drought monitoring is crucial for assessing and mitigating the impacts of water scarcity on various sectors and ecosystems. Although traditional drought monitoring relies on soil moisture data, remote sensing technology has have significantly augmented the capabilities for drought monitoring. This study aims to evaluate the accuracy and applicability of two temperature vegetation drought indices (TVDI), TVDINDVI and TVDIEVI, constructed using the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) vegetation indices for drought monitoring. Using Guangdong Province as a case, enhanced versions of these indices, developed through Savitzky-Golay filtering and terrain correction were employed. Additionally, Pearson correlation analysis and F-tests were utilized to determine the suitability of the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) in correlation with TVDINDVI and TVDIEVI. The results show that TVDINDVI had more meteorological stations passing both significance test levels (P

Matched MeSH terms: Temperature
Fulltext Characterization of Sphingobacterium sp. Ab3 Lipase and Its Coexpression with LEA Peptides

Ng YK, Ikeno S, Kadhim Almansoori AK, Muhammad I, Abdul Rahim R

Microbiol Spectr, 2022 Dec 21;10(6):e0142221.
PMID: 36314920 DOI: 10.1128/spectrum.01422-21

Sphingobacterium sp. is a yellowish Gram-negative bacterium that is usually characterized by high concentrations of sphingophospholipids as lipid components. As microbial enzymes have been in high demand in industrial fields in the past few decades, this study hopes to provide significant information on lipase activities of Sphingobacterium sp., since limited studies have been conducted on the Sphingobacterium sp. lipase. A microbe from one collected Artic soil sample, ARC4, was identified as psychrotolerant Sphingobacterium sp., and it could grow in temperatures ranging from 0°C to 24°C. The expression of Sphingobacterium sp. lipase was successfully performed through an efficient approach of utilizing mutated group 3 late embryogenesis abundant (G3LEA) proteins developed from Polypedilum vanderplanki. Purified enzyme was characterized using a few parameters, such as temperature, pH, metal ion cofactors, organic solvents, and detergents. The expressed enzyme is reported to be cold adapted and has the capability to work efficiently under neutral pH (pH 5.0 to 7.0), cofactors like Na+ ion, and the water-like solvent methanol. Addition of nonionic detergents greatly enhanced the activity of purified enzyme. IMPORTANCE The mechanism of action of LEA proteins has remained unknown to many; in this study we reveal their presence and improved protein expression due to the molecular shielding effect reported by others. This paper should be regarded as a useful example of using such proteins to influence an existing expression system to produce difficult-to-express proteins.

Matched MeSH terms: Temperature
Catalytic pyrolysis of high-density polyethylene over nickel-waste chicken eggshell/HZSM-5

Mohamad Dzol MAA, Balasundram V, Shameli K, Ibrahim N, Manan ZA, Isha R

J Environ Manage, 2022 Dec 15;324:116392.
PMID: 36208512 DOI: 10.1016/j.jenvman.2022.116392

The main objective of the current work is to investigate the effect of nickel-waste chicken eggshell modified Hydrogen exchanged Zeolite Socony Mobil-5 (Ni-WCE/HZSM-5) on pyrolysis of high-density polyethylene (HDPE). Ni-WCE/HZSM-5 was synthesized via the impregnation incipient wetness (IWI) method with Ni and WCE mass loading of 4 and 12 wt% respectively. HZSM-5, CaO, WCE, WCE/HZSM-5, and Ni/HZSM-5 were prepared for comparison purposes with Ni-WCE/HZSM-5. All the synthesized catalysts were characterized for phase analysis, metal loading, surface morphology, and textural properties. The impregnation of nickel and WCE had significantly affected the original framework of HZSM-5, where the crystallinity percentage and average crystal size of HZSM-5 dropped to 44.97% and increased to 47.90 nm respectively. The surface morphology of HZSM-5 has drastically changed from a cubic-like shape into a spider web-like surface after the impregnation of WCE. The BET surface area of HZSM-5 has been lowered due to the impregnation of nickel and WCE, but the total pore volume has increased greatly from 0.2291 cm3/g to 0.2621 cm3/g. The catalyst performance was investigated in the pyrolysis of HDPE via a fixed bed reactor and the pyrolysis oil was further analysed to evaluate the distribution of C6 to C9> hydrocarbons. Among the tested catalytic samples, the highest pyrolysis oil yield was achieved by WCE (80%) followed by CaO (78%), WCE/HZSM-5 (63%), HZSM-5 (61%), Ni/HZSM-5 (44%) and Ni-WCE/HZSM-5 (50%). For hydrocarbon distribution in pyrolysis oil, the Ni/HZSM-5 produced the highest of total C6 and C7 hydrocarbons at 12% and 27% respectively followed by WCE/HZSM-5 (4% and 20%), non-catalytic (5% and 13%), Ni-WCE/HZSM-5 (0% and 15%), WCE (0% and 10%), HZSM-5 (0% and 6%) and CaO (0% and 0%).

Matched MeSH terms: Hot Temperature
Fulltext The Impact of Heatwaves on Mortality and Morbidity and the Associated Vulnerability Factors: A Systematic Review

Arsad FS, Hod R, Ahmad N, Ismail R, Mohamed N, Baharom M, et al.

Int J Environ Res Public Health, 2022 Dec 06;19(23).
PMID: 36498428 DOI: 10.3390/ijerph192316356

BACKGROUND: This study aims to investigate the current impacts of extreme temperature and heatwaves on human health in terms of both mortality and morbidity. This systematic review analyzed the impact of heatwaves on mortality, morbidity, and the associated vulnerability factors, focusing on the sensitivity component.
METHODS: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 flow checklist. Four databases (Scopus, Web of Science, EBSCOhost, PubMed) were searched for articles published from 2012 to 2022. Those eligible were evaluated using the Navigation Guide Systematic Review framework.
RESULTS: A total of 32 articles were included in the systematic review. Heatwave events increased mortality and morbidity incidence. Sociodemographic (elderly, children, male, female, low socioeconomic, low education), medical conditions (cardiopulmonary diseases, renal disease, diabetes, mental disease), and rural areas were crucial vulnerability factors.
CONCLUSIONS: While mortality and morbidity are critical aspects for measuring the impact of heatwaves on human health, the sensitivity in the context of sociodemographic, medical conditions, and locality posed a higher vulnerability to certain groups. Therefore, further research on climate change and health impacts on vulnerability may help stakeholders strategize effective plans to reduce the effect of heatwaves.

Matched MeSH terms: Hot Temperature
Fulltext Cold-Active Lipases and Esterases: A Review on Recombinant Overexpression and Other Essential Issues

Matinja AI, Kamarudin NHA, Leow ATC, Oslan SN, Ali MSM

Int J Mol Sci, 2022 Dec 06;23(23).
PMID: 36499718 DOI: 10.3390/ijms232315394

Cold environments characterised by diverse temperatures close to or below the water freezing point dominate about 80% of the Earth's biosphere. One of the survival strategies adopted by microorganisms living in cold environments is their expression of cold-active enzymes that enable them to perform an efficient metabolic flux at low temperatures necessary to thrive and reproduce under those constraints. Cold-active enzymes are ideal biocatalysts that can reduce the need for heating procedures and improve industrial processes' quality, sustainability, and cost-effectiveness. Despite their wide applications, their industrial usage is still limited, and the major contributing factor is the lack of complete understanding of their structure and cold adaptation mechanisms. The current review looked at the recombinant overexpression, purification, and recent mechanism of cold adaptation, various approaches for purification, and three-dimensional (3D) crystal structure elucidation of cold-active lipases and esterase.

Matched MeSH terms: Cold Temperature
Deviations in red cell blood component temperature during laboratory processing and at blood return monitored by a time-temperature indicator device

Cheng JY, Samudram H, Lee Lai Ling C, Nadarajan VS

Transfus Med, 2022 Dec;32(6):484-491.
PMID: 36239101 DOI: 10.1111/tme.12924

OBJECTIVES: To evaluate the performance and utility of a time-temperature indicator (TTI) to determine the cumulative exposure time (CET) of red cell components (RCC) to temperatures above 10°C occurring within and outside the transfusion laboratory.
BACKGROUND AND OBJECTIVES: Blood centres often use the '30 or 60-min rule' for accepting RCC exposed to room temperature (RT) back into inventory. Effective monitoring of these temperature deviations is however lacking.
MATERIALS AND METHODS: A Timestrip PLUS® TP153 10°C (TS + 10) TTI was attached to RCC units after preparation of the unit in the blood bank or on issue to the ward, to track the CET > 10°C during laboratory processing and outside the transfusion laboratory.
RESULTS: The mean CET of 153 RCC tracked within the laboratory was 56 min. Sixty-four (41.8%) and 34 (22.2%) of RCC had core temperature (CT) >10°C for more than 30 and 60 min, respectively. Among the 69 RCC that were returned unused, 27 (39.1%), 17 (24.6%) and 5 (7.2%) RCC units had CT >10°C for more than 30, 60 and 120 min respectively.
CONCLUSION: A large proportion of RCC have CT >10°C exceeding 30 min during handling within the transfusion laboratory, as well as when RCC are returned unused from transfusion locations. Corrective measures should be implemented to better manage the cold chain to avoid undesirable consequences to blood transfusion. A temperature sensitive device that can also indicate CET can be employed to objectively monitor the period that RCC remained at a CT that exceeds 10°C.

Matched MeSH terms: Temperature
Formation of 3-MCPD and glycidyl esters in biscuits produced using soybean oil-based diacylglycerol stearin-shortening blends: Impacts of different baking temperatures and blending ratios

Shafika Abdul Kadir N, Khor YP, Lee YJ, Lan D, Qi S, Wang Y, et al.

Food Res Int, 2022 Dec;162(Pt B):112055.
PMID: 36461315 DOI: 10.1016/j.foodres.2022.112055

Diacylglycerol (DAG) is commonly known as one of the precursors for 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) formation. Besides, 3-MCPDE and GE are heat-induced contaminants which can be formed in fat-containing baked products during the baking process. This study attempted to replace the conventional palm-based shortening (SH) with a healthier fat, namely soybean oil-based diacylglycerol stearin (SDAG) in producing biscuits. The effects of different baking temperatures (200, 210 and 220 °C) and SDAG:SH fat blend ratios (0:100, 60:40 (D64S), 80:20 (D82S), 100:0, w/w) towards the biscuits' physical properties were evaluated. Moreover, the oxidative stability, 3-MCPDPE and GE formation in the fats extracted from the biscuits were also investigated. SDAG-produced biscuit showed slight reductions in the spread ratio compared to the SH-produced biscuit. The elevated baking temperatures resulted in biscuits with increased hardness and low moisture content. Pure SDAG and the other fat blends exhibited significant (p

Matched MeSH terms: Temperature
An in silico derived dosage and administration guide for effective thermochemical ablation of biological tissues with simultaneous injection of acid and base

Mak NL, Ooi EH, Lau EV, Ooi ET, Pamidi N, Foo JJ, et al.

Comput Methods Programs Biomed, 2022 Dec;227:107195.
PMID: 36323179 DOI: 10.1016/j.cmpb.2022.107195

BACKGROUND AND OBJECTIVES: Thermochemical ablation (TCA) is a thermal ablation technique involving the injection of acid and base, either sequentially or simultaneously, into the target tissue. TCA remains at the conceptual stage with existing studies unable to provide recommendations on the optimum injection rate, and reagent concentration and volume. Limitations in current experimental methodology have prevented proper elucidation of the thermochemical processes inside the tissue during TCA. Nevertheless, the computational TCA framework developed recently by Mak et al. [Mak et al., Computers in Biology and Medicine, 2022, 145:105494] has opened new avenues in the development of TCA. Specifically, a recommended safe dosage is imperative in driving TCA research beyond the conceptual stage.
METHODS: The aforesaid computational TCA framework for sequential injection was applied and adapted to simulate TCA with simultaneous injection of acid and base at equimolar and equivolume. The developed framework, which describes the flow of acid and base, their neutralisation, the rise in tissue temperature and the formation of thermal damage, was solved numerically using the finite element method. The framework will be used to investigate the effects of injection rate, reagent concentration, volume and type (weak/strong acid-base combination) on temperature rise and thermal coagulation formation.
RESULTS: A higher injection rate resulted in higher temperature rise and larger thermal coagulation. Reagent concentration of 7500 mol/m3 was found to be optimum in producing considerable thermal coagulation without the risk of tissue overheating. Thermal coagulation volume was found to be consistently larger than the total volume of acid and base injected into the tissue, which is beneficial as it reduces the risk of chemical burn injury. Three multivariate second-order polynomials that express the targeted coagulation volume as functions of injection rate and reagent volume, for the weak-weak, weak-strong and strong-strong acid-base combinations were also derived based on the simulated data.
CONCLUSIONS: A guideline for a safe and effective implementation of TCA with simultaneous injection of acid and base was recommended based on the numerical results of the computational model developed. The guideline correlates the coagulation volume with the reagent volume and injection rate, and may be used by clinicians in determining the safe dosage of reagents and optimum injection rate to achieve a desired thermal coagulation volume during TCA.

Matched MeSH terms: Hot Temperature; Temperature

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links