MyMedR

Displaying publications 341 - 360 of 1115 in total

Abstract:

Sort:

Techno-economic assessment of hydrotreated vegetable oil as a renewable fuel from waste sludge palm oil

Hor CJ, Tan YH, Mubarak NM, Tan IS, Ibrahim ML, Yek PNY, et al.

Environ Res, 2023 Mar 01;220:115169.
PMID: 36587722 DOI: 10.1016/j.envres.2022.115169

To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO2) emission by up to 90% and the total annual production cost by nearly RM 450 million. Therefore, SPO-HVO production is a potential and alternative process to produce biobased diesel fuels with waste oil.

Matched MeSH terms: Oxygen
Intraoperative Inspiratory Oxygen Fraction and Myocardial Injury After Noncardiac Surgery: Results From an International Observational Study in Relation to Recent Controlled Trials

Pedersen SS, Holse C, Mathar CE, Chan MTV, Sessler DI, Liu Y, et al.

Anesth Analg, 2022 Nov 01;135(5):1021-1030.
PMID: 35417425 DOI: 10.1213/ANE.0000000000006042

BACKGROUND: Two trials reported that a high inspiratory oxygen fraction (F io2 ) does not promote myocardial infarction or death. Observational studies can provide larger statistical strength, but associations can be due to unobserved confounding. Therefore, we evaluated the association between intraoperative F io2 and cardiovascular complications in a large international cohort study to see if spurious associations were observed.
METHODS: We included patients from the Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) study, who were ≥45 years of age, scheduled for overnight hospital admission, and had intraoperative F io2 recorded. The primary outcome was myocardial injury after noncardiac surgery (MINS), and secondary outcomes included mortality and pneumonia, all within 30 postoperative days. Data were analyzed with logistic regression, adjusted for many baseline cardiovascular risk factors, and illustrated in relation to findings from 2 recent controlled trials.
RESULTS: We included 6588 patients with mean age of 62 years of whom 49% had hypertension. The median intraoperative F io2 was 0.46 (5%-95% range, 0.32-0.94). There were 808 patients (12%) with MINS. Each 0.10 increase in median F io2 was associated with a confounder-adjusted increase in odds for MINS: odds ratio (OR), 1.17 (95% confidence interval [CI], 1.12-1.23; P < .0001). MINS occurred in contrast with similar frequencies and no significant difference in controlled trials (2240 patients, 194 events), in which patients were given 80% vs 30% oxygen. Mortality was 2.4% and was not significantly associated with a median F io2 (OR, 1.07; 95% CI, 0.97-1.19 per 0.10 increase; P = .18), and 2.9% of patients had pneumonia (OR, 1.05; 95% CI, 0.95-1.15 per 0.10 increase; P = .34).
CONCLUSIONS: We observed an association between intraoperative F io2 and risk of myocardial injury within 30 days after noncardiac surgery, which contrasts with recent controlled clinical trials. F io2 was not significantly associated with mortality or pneumonia. Unobserved confounding presumably contributed to the observed association between F io2 and myocardial injury that is not supported by trials.

Matched MeSH terms: Oxygen
Digital health intervention in patients undergoing cardiac rehabilitation: systematic review and meta-analysis

Harbi AS, Soh KL, Yubbu PB, Soh KG

F1000Res, 2024;13:596.
PMID: 38984016 DOI: 10.12688/f1000research.152315.1

BACKGROUND: Cardiovascular disease (CVD) continues to be the foremost mortality internationally. Cardiac rehabilitation has proven as an effective program in reducing CVD burden. Participation in cardiac rehabilitation programs is very low. Digital health intervention emerged as an alternative method to deliver Cardiac rehabilitation. This review aimed to investigate the impact of digital health intervention on the outcomes of interest.
METHODS: the following databases: PubMed, CINAHL, Scopus, and Cochrane Library have been searched to retrieve randomized controlled trials that examine the impact of digital health intervention on blood pressure, body mass index, lipid profile, blood glucose, Six-Minute Walk Test, and peak oxygen consumption. filters were set to include studies published in English between 2000-2023.
RESULTS: Nineteen studies were included in this review. Six-Minute Walk Test (MD = 16.70; 95% CI: 6.00 to 27.39, p = 0.000) and maximal oxygen consumption (SMD = 0.27; 95% CI: 0.08 to 0.45, p = 0.004) significantly improved following digital health intervention, after employing the sensitivity analysis significant improvement was observed in systolic (MD = -2.54; 95% CI: -4.98 to -0.11, p = 0.04) and diastolic blood pressure (SMD = -2.0182; 95% CI: -3.9436 to -0.0928, p = 0.04) favoring experimental groups. Subgroup analysis revealed significant improvement in quality of life after three months of follow-up (SMD = 0.18; 95% CI: 0.05 to 0.31, p = 0.00), no significant differences have been observed in body mass index, lipid profile, and blood glucose.
CONCLUSION: The findings emphasize the significant impact of digital vs CBCR or usual care on physical capacity, blood pressure, and quality of life. Despite the non-statistically significant differences in body mass index and lipid profile, the comparable effect between the two methods suggests the superiority of digital over CBCR or usual care due to its convenient nature, accessibility, and cost-effectiveness.

Matched MeSH terms: Oxygen Consumption
Fulltext Bioprospecting of bacteria from textile effluents for enhanced dye biodegradation

Gebreyohannes G, Zenawi B, Hidru GG, Fitsum S, Sbhatu DB

Sci Rep, 2026 Jun 13;16(1).
PMID: 42288614 DOI: 10.1038/s41598-026-56447-z

The textile industry is a major contributor to water pollution, releasing effluents containing 10-15% unused synthetic dyes. These dyes have complex aromatic structures that resist biodegradation, posing serious risks to aquatic ecosystems and human health. This study evaluated the physicochemical properties of wastewater from the Maa Garment Textile Factory and investigated the bioremediation potential of indigenous bacterial isolates. Effluent samples collected from different treatment points were analyzed for pH, temperature, total suspended solids (TSS), total dissolved solids (TDS), biological oxygen demand (BOD), and chemical oxygen demand (COD). The wastewater exhibited a neutral to slightly alkaline pH (7.2-7.5), favorable for microbial activity, but had elevated temperatures (up to 38 °C) and high TDS (2633-2866 mg/L), indicating thermal and chemical pollution. A total of 30 bacterial isolates were screened for their ability to biodegrade reactive red, blue, and yellow dyes under varying conditions of temperature (25-40 °C), pH (5-9), and dye concentration (50-150 mg/L). Sixteen isolates demonstrated biodegradation capacity, with optimal performance (mean 89.4%) observed at 37 °C, pH 7, and 50 mg/L dye concentration, and significant variation across tested conditions (p

Matched MeSH terms: Biological Oxygen Demand Analysis
Treatment of diluted palm oil mill effluent (POME) synchronous with electricity production in a persulfate oxidant-promoted photocatalytic fuel cell

Yap CJ, Lam SM, Sin JC, Zeng H, Li H, Huang L, et al.

Environ Sci Pollut Res Int, 2023 Sep;30(42):96272-96289.
PMID: 37566326 DOI: 10.1007/s11356-023-29165-6

Attributable to the prosperous production growth of palm oil in Malaysia, the generated palm oil mill effluent (POME) poses a high threat owing to its highly polluted characteristic. Urged by the escalating concern of environmental conservation, POME pollution abatement and potential energy recovery from the effluent are flagged up as a research topic of interest. In this study, a cutting-edge photocatalytic fuel cell (PFC) system with employment of ZnO/Zn nanorod array (NRA) photoanode, CuO/Cu cathode, and persulfate (PS) oxidant was successfully designed to improve the treatment of POME and simultaneous energy production. The photoelectrodes were fabricated and characterized by field emission scanning electron microscopy with energy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Brunauer, Emmett, and Teller analysis (BET). Owing to the properties of strong oxidant of PS, the proposed PFC/PS system has exhibited exceptional performance, attaining chemical oxygen demand (COD) removal efficiency of 96.2%, open circuit voltage (Voc) of 740.0 mV, short circuit current density (Jsc) of 146.7 μA cm-2, and power density (Pmax) of 35.6 μW cm-2. The pre-eminent PFC/PS system performance was yielded under optimal conditions of 2.5 mM of persulfate oxidant, POME dilution factor of 1:20, and natural solution pH of 8.51. Subsequently, the postulated photoelectrocatalytic POME treatment mechanism was elucidated by the radical scavenging study and Mott-Schottky (M-S) analysis. The following recycling test affirmed the stability and durability of the photoanode after four continuous repetition usages while the assessed electrical energy efficiency revealed the economic viability of PFC system serving as a post-treatment for abatement of POME. These findings contributed toward enhancing the sustainability criteria and economic viability of palm oil by adopting sustainable and efficient POME post-treatment technology.

Matched MeSH terms: Biological Oxygen Demand Analysis
An insight into the role of experimental parameters in advanced oxidation process applied for pharmaceutical degradation

Qutob M, Alshehri S, Shakeel F, Alam P, Rafatullah M

Environ Sci Pollut Res Int, 2024 Apr;31(18):26452-26479.
PMID: 38546921 DOI: 10.1007/s11356-024-33040-3

The advanced oxidation process (AOP) is an efficient method to treat recalcitrance pollutants such as pharmaceutical compounds. The essential physicochemical factors in AOP experiments significantly influence the efficiency, speed, cost, and safety of byproducts of the treatment process. In this review, we collected recent articles that investigated the elimination of pharmaceutical compounds by various AOP systems in a water medium, and then we provide an overview of AOP systems, the formation mechanisms of active radicals or reactive oxygen species (ROS), and their detection methods. Then, we discussed the role of the main physicochemical parameters (pH, chemical interference, temperature, catalyst, pollutant concentration, and oxidant concentration) in a critical way. We gained insight into the most frequent scenarios for the proper and improper physicochemical parameters for the degradation of pharmaceutical compounds. Also, we mentioned the main factors that restrict the application of AOP systems in a commercial way. We demonstrated that a proper adjustment of AOP experimental parameters resulted in promoting the treatment performance, decreasing the treatment cost and the treatment operation time, increasing the safeness of the system products, and improving the reaction stoichiometric efficiency. The outcomes of this review will be beneficial for future AOP applicants to improve the pharmaceutical compound treatment by providing a deeper understanding of the role of the parameters. In addition, the proper application of physicochemical parameters in AOP systems acts to track the sustainable development goals (SDGs).

Matched MeSH terms: Reactive Oxygen Species
Degradation of 17α-ethinylestradiol by nano zero valent iron under different pH and dissolved oxygen levels

Karim S, Bae S, Greenwood D, Hanna K, Singhal N

Water Res, 2017 11 15;125:32-41.
PMID: 28826034 DOI: 10.1016/j.watres.2017.08.029

The catalytic properties of nanoparticles (e.g., nano zero valent iron, nZVI) have been used to effectively treat a wide range of environmental contaminants. Emerging contaminants such as endocrine disrupting chemicals (EDCs) are susceptible to degradation by nanoparticles. Despite extensive investigations, questions remain on the transformation mechanism on the nZVI surface under different environmental conditions (redox and pH). Furthermore, in terms of the large-scale requirement for nanomaterials in field applications, the effect of polymer-stabilization used by commercial vendors on the above processes is unclear. To address these factors, we investigated the degradation of a model EDC, the steroidal estrogen 17α-ethinylestradiol (EE2), by commercially sourced nZVI at pH 3, 5 and 7 under different oxygen conditions. Following the use of radical scavengers, an assessment of the EE2 transformation products shows that under nitrogen purging direct reduction of EE2 by nZVI occurred at all pHs. The radicals transforming EE2 in the absence of purging and upon air purging were similar for a given pH, but the dominant radical varied with pH. Upon air purging, EE2 was transformed by the same radical species as the non-purged system at the same respective pH, but the degradation rate was lower with more oxygen - most likely due to faster nZVI oxidation upon aeration, coupled with radical scavenging. The dominant radicals were OH at pH 3 and O2- at pH 5, and while neither radical was involved at pH 7, no conclusive inferences could be made on the actual radical involved at pH 7. Similar transformation products were observed without purging and upon air purging.

Matched MeSH terms: Oxygen/chemistry
Responses of phytoplankton community to eutrophication in Semerak Lagoon (Malaysia)

Er HH, Lee LK, Lim ZF, Teng ST, Leaw CP, Lim PT

Environ Sci Pollut Res Int, 2018 Aug;25(23):22944-22962.
PMID: 29858995 DOI: 10.1007/s11356-018-2389-0

Effects of aquaculture activities on the environmental parameters and phytoplankton community structure were investigated in a semi-enclosed lagoon located at Semerak River, Malaysia. Elevated concentrations of phosphate and ammonia were observed at the aquaculture area and the inner lagoon. Relatively low dissolved oxygen, high total chlorophyll a, and high phytoplankton abundances but low species richness were recorded. Chaetoceros, Pseudo-nitzschia brasiliana, Blixaea quinquecornis, and Skeletonema blooms were observed, and some were associated with anoxia condition. Eutrophication level assessed by UNTRIX suggests that the water quality in the lagoon is deteriorating. Dissolved inorganic phosphorus and nitrogen at the impacted area were 15 and 12 times higher than the reference sites, respectively. Such trophic status indices could provide a useful guideline for optimal aquaculture management plan to reduce the environmental impact caused by aquaculture.

Matched MeSH terms: Oxygen/analysis
Zinc and Metallothionein in the Development and Progression of Dental Caries

Rahman MT, Hossain A, Pin CH, Yahya NA

Biol Trace Elem Res, 2019 Jan;187(1):51-58.
PMID: 29744817 DOI: 10.1007/s12011-018-1369-z

Chronic oxidative stress and reactive oxygen species (ROS) in oral cavity as well as acidic pH on dental enamel surface due to the metabolic activities of bacterial plaque are the major contributors in the development and progression of dental caries. Along with other factors, deposition or dissolution Ca and Mg mostly determines the re- or demineralization of dental enamel. Zn plays an important role for both Ca and Mg bioavailability in oral cavity. Metallothionein (MT), a group of small molecular weight, cysteine-rich proteins (~ 7 kDa), is commonly induced by ROS, bacterial infection, and Zn. In the current review, we evaluated MT at the junction between the progression of dental caries and its etiologies that are common in MT biosynthesis.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Bilateral tension pneumothorax after acupuncture

Mohammad N

BMJ Case Rep, 2018 Apr 19;2018.
PMID: 29674395 DOI: 10.1136/bcr-2017-221550

Acupuncture is an ancient complementary medicine which is currently used worldwide. Many serious adverse events have been reported which include a spectrum of mild-to-fatal complications. However, the level of awareness with regard to complications is still low both to physicians and patients. We report a 63-year-old who presented with acute shortness of breath 2 hours after having had acupuncture. On examination, there was absent breath sound heard on the left lung and slightly reduced breath sound on the right lung. She had type 1 respiratory failure. Urgent chest radiograph confirmed bilateral pneumothorax which was more severe on the left with tension pneumothorax and mediastinal shift. Chest tubes were inserted bilaterally after failed needle aspiration attempts. Subsequently, the pneumothoraces resolved, and she was discharged well. The bilateral pneumothoraces caused by acupuncture were curable but could have been potentially fatal if diagnosis was delayed. This case report adds to the limited current literature on the complications of acupuncture leading to bilateral pneumothoraces.

Matched MeSH terms: Oxygen Inhalation Therapy/methods*
Fulltext Reactive oxygen species and male reproductive hormones

Darbandi M, Darbandi S, Agarwal A, Sengupta P, Durairajanayagam D, Henkel R, et al.

Reprod Biol Endocrinol, 2018 Sep 11;16(1):87.
PMID: 30205828 DOI: 10.1186/s12958-018-0406-2

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

Matched MeSH terms: Reactive Oxygen Species/metabolism*
Fulltext Nanotechnology in drug delivery gaining new perspectives in respiratory diseases

Dua K, Madan JR, Chellappan DK, Gupta G

Panminerva Med, 2018 09;60(3):135-136.
PMID: 30176702 DOI: 10.23736/S0031-0808.18.03442-0
Matched MeSH terms: Reactive Oxygen Species/chemistry
Fulltext Poultry Slaughterhouse Wastewater Treatment Using Submerged Fibers in an Attached Growth Sequential Batch Reactor

Aziz HA, Puat NNA, Alazaiza MYD, Hung YT

Int J Environ Res Public Health, 2018 08 13;15(8).
PMID: 30104522 DOI: 10.3390/ijerph15081734

In this study, a sequential batch reactor (SBR) with different types of fibers was employed for the treatment of poultry slaughterhouse wastewater. Three types of fibers, namely, juite fiber (JF), bio-fringe fiber (BF), and siliconised conjugated polyester fiber (SCPF), were used. Four SBR experiments were conducted, using the fibers in different reactors, while the fourth reactor used a combination of these fibers. The treatment efficiency of the different reactors with and without fibers on biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia-nitrogen (NH₃-N), phosphorus (P), nitrite (NO₂), nitrate (NO₃), total suspended solids (TSS), and oil-grease were evaluated. The removal efficiency for the reactors with fibers was higher than that of the reactor without fibers for all pollutants. The treated effluent had 40 mg/L BOD₅ and 45 mg/L COD with an average removal efficiency of 96% and 93%, respectively, which meet the discharge limits stated in the Environmental Quality Act in Malaysia.

Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis
Borg CR-10 scale as a new approach to monitoring office exercise training

Shariat A, Cleland JA, Danaee M, Alizadeh R, Sangelaji B, Kargarfard M, et al.

Work, 2018;60(4):549-554.
PMID: 30103362 DOI: 10.3233/WOR-182762

BACKGROUND: There are many potential training exercises for office workers in an attempt to prevent musculoskeletal disorders. However, to date a suitable tool to monitor the perceived exertion of those exercises does not exist.
OBJECTIVE: The primary objective of this study was to examine the validity and reliability of the Borg CR-10 scale to monitor the perceived exertion of office exercise training.
METHODS: The study involved 105 staff members employed in a government office with an age range from 25 to 50 years. The Borg CR-10 scale was self-administered two times, with an interval of two weeks in order to evaluate the accuracy of the original findings with a retest. Face validity and content validity were also examined.
RESULTS: Reliability was found to be high for the Borg CR-10 scale (0.898). Additionally a high correlation between the Borg CR-10 scale and Visual Analog Scale (VAS) was identified (rs = 0.754, P

Matched MeSH terms: Oxygen Consumption/physiology
Metabolic Syndrome and Its Effect on the Brain: Possible Mechanism

Arshad N', Lin TS, Yahaya MF

CNS Neurol Disord Drug Targets, 2018;17(8):595-603.
PMID: 30047340 DOI: 10.2174/1871527317666180724143258

BACKGROUND & OBJECTIVE: Metabolic syndrome (MetS) is an interconnected group of physiological, biochemical, clinical and metabolic factors that directly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) and mortality. Rising evidence suggests that MetS plays a significant role in the progression of Alzheimer's disease and other neurodegenerative diseases. Nonetheless, the factors linking this association has not yet been elucidated. As we are facing an increasing incidence of obesity and T2DM in all stages of life, understanding the association of MetS and neurodegenerative diseases is crucial to lessen the burden of the disease.
CONCLUSION: In this review, we will discuss the possible mechanisms which may relate the association between MetS and cognitive decline which include vascular damages, elevation of reactive oxygen species (ROS), insulin resistance and low-grade inflammation.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Modulation of age related protein expression changes by gelam honey in cardiac mitochondrial rats

Hasenan SM, Karsani SA, Jubri Z

Exp Gerontol, 2018 11;113:1-9.
PMID: 30248357 DOI: 10.1016/j.exger.2018.09.001

Aging is characterized by progressive decline in biochemical and physiological functions. According to the free radical theory of aging, aging results from oxidative damage due to the accumulation of excess reactive oxygen species (ROS). Mitochondria are the main source of ROS production and are also the main target for ROS. Therefore, a diet high in antioxidant such as honey is potentially able to protect the body from ROS and oxidative damage. Gelam honey is higher in flavonoid content and phenolic compounds compared to other local honey. This study was conducted to determine the effects of gelam honey on age related protein expression changes in cardiac mitochondrial rat. A total of 24 Sprague-Dawley male rats were divided into two groups: the young group (2 months old), and aged group (19 months old). Each group were then subdivided into two groups: control group (force-fed with distilled water), and treatment group (force-fed with gelam honey, 2.5 g/kg), and were treated for 8 months. Comparative proteomic analysis of mitochondria from cardiac tissue was then performed by high performance mass spectrometry (Q-TOF LCMS/MS) followed by validation of selected proteins by Western blotting. Proteins were identified using Spectrum Mill software and were subjected to stringent statistical analysis. A total of 286 proteins were identified in the young control group (YC) and 241 proteins were identified in the young gelam group (YG). In the aged group, a total of 243 proteins were identified in control group (OC), and 271 proteins in gelam group (OG). Comparative proteome profiling identified 69 proteins with different abundance (p 

Matched MeSH terms: Reactive Oxygen Species/metabolism*
Fulltext Biohydrogen Production by Antarctic Psychrotolerant Klebsiella sp. ABZ11

Mohammed A, Abdul-Wahab MF, Hashim M, Omar AH, Md Reba MN, Muhamad Said MF, et al.

Pol J Microbiol, 2018 11 20;67(3):283-290.
PMID: 30451444 DOI: 10.21307/pjm-2018-033

Lower temperature biohydrogen production has always been attractive, due to the lower energy requirements. However, the slow metabolic rate of psychrotolerant biohydrogen-producing bacteria is a common problem that affects their biohydrogen yield. This study reports on the improved substrate synthesis and biohydrogen productivity by the psychrotolerant Klebsiella sp. strain ABZ11, isolated from Antarctic seawater sample. The isolate was screened for biohydrogen production at 30°C, under facultative anaerobic condition. The isolate is able to ferment glucose, fructose and sucrose with biohydrogen production rate and yield of 0.8 mol/l/h and 3.8 mol/g, respectively at 10 g/l glucose concentration. It also showed 74% carbohydrate uptake and 95% oxygen uptake ability, and a wide growth temperature range with optimum at 37°C. Klebsiella sp. ABZ11 has a short biohydrogen production lag phase, fast substrate uptake and is able to tolerate the presence of oxygen in the culture medium. Thus, the isolate has a potential to be used for lower temperature biohydrogen production process.

Matched MeSH terms: Oxygen/metabolism
Perceptual and Cardiorespiratory Responses to High-Intensity Interval Exercise in Adolescents: Does Work Intensity Matter?

Malik AA, Williams CA, Weston KL, Barker AR

J Sports Sci Med, 2019 03;18(1):1-12.
PMID: 30787646

High-intensity interval exercise (HIIE) may not elicit prominent unpleasant feelings even with elevated perceived exertion and physiological stress in adolescents. However, the influence of different HIIE work intensities on the affective experience and cardiorespiratory responses is unknown. This study examined the acute affective, enjoyment, perceived exertion and cardiorespiratory responses to HIIE with different work intensities in adolescents. Participants (n = 16; 8 boys; age 12.0 ± 0.3 years) performed, on separate days, HIIE conditions consisting of 8 x 1-minute work-intervals at 70%, 85%, or 100% peak power separated by 75 seconds recovery at 20 W. Affect, enjoyment and rating of perceived exertion (RPE) were recorded before, during, and after HIIE. Heart rate (HR) and oxygen uptake were collected during HIIE. Affect declined in all conditions (p < 0.01) but 100%HIIE elicited significantly lower affect than 70%HIIE and 85%HIIE at work-interval 8 (all p < 0.02, ES > 1.74; 70%HIIE = 2.5 ± 0.8; 85%HIIE = 1.1 ± 1.5; 100%HIIE = -1.5 ± 1.4 on feeling scale). Similar enjoyment was evident during and after all conditions (all p > 0.44). RPE was significantly higher during 100%HIIE than 70%HIIE and 85%HIIE across all work-intervals (all p < 0.01, ES > 1.56). The majority of the participants attained ≥90%HRmax during 85%HIIE (87%) and 100%HIIE (100%), but not during 70%HIIE (6%). Affect responses during HIIE are dependent on the intensity of the work-interval and are not entirely negative (unpleasant feelings). Despite similar enjoyment, positive affect experienced during 70%HIIE and 85%HIIE could serve as a strategy to encourage exercise adoption and adherence in adolescents, but only 85%HIIE elicits sufficient HR stimulus to facilitate potential health benefits.

Matched MeSH terms: Oxygen Consumption/physiology
Investigating effect of proton-exchange membrane on new air-cathode single-chamber microbial fuel cell configuration for bioenergy recovery from Azorubine dye degradation

Kardi SN, Ibrahim N, Rashid NAA, Darzi GN

Environ Sci Pollut Res Int, 2019 Jul;26(21):21201-21215.
PMID: 31115820 DOI: 10.1007/s11356-019-05204-z

One of the biggest challenges of using single-chamber microbial fuel cells (MFCs) that utilize proton-exchange membrane (PEM) air cathode for bioenergy recovery from recalcitrant organic compounds present in wastewater is mainly attributed to their high internal resistance in the anodic chamber of the single microbial fuel cell (MFC) configurations. The high internal resistance is due to the small surface area of the anode and cathode electrodes following membrane biofouling and pH splitting conditions as well as substrate and oxygen crossover through the membrane pores by diffusion. To address this issue, the fabrication of new PEM air-cathode single-chamber MFC configuration was investigated with inner channel flow open assembled with double PEM air cathodes (two oxygen reduction activity zones) coupled with spiral-anode MFC (2MA-CsS-AMFC). The effect of various proton-exchange membranes (PEMs), including Nafion 117 (N-117), Nafion 115 (N-115), and Nafion 212 (N-212) with respective thicknesses of 183, 127, and 50.08 μ, was separately incorporated into carbon cloth as PEM air-cathode electrode to evaluate their influences on the performance of the 2MA-CsS-AMFC configuration operated in fed-batch mode, while Azorubine dye was selected as the recalcitrant organic compound. The fed-batch test results showed that the 2MA-CsS-AMFC configuration with PEM N-115 operated at Azorubine dye concentration of 300 mg L-1 produced the highest power density of 1022.5 mW m-2 and open-circuit voltage (OCV) of 1.20 V coupled with enhanced dye removal (4.77 mg L h-1) compared to 2MA-CsS-AMFCs with PEMs N-117 and N-212 and those in previously published data. Interestingly, PEM 115 showed remarkable reduction in biofouling and pH splitting. Apart from that, mass transfer coefficient of PEM N-117 was the most permeable to oxygen (KO = 1.72 × 10-4 cm s-1) and PEM N-212 was the most permeable membrane to Azorubine (KA = 7.52 × 10-8 cm s-1), while PEM N-115 was the least permeable to both oxygen (KO = 1.54 × 10-4) and Azorubine (KA = 7.70 × 10-10). The results demonstrated that the 2MA-CsS-AMFC could be promising configuration for bioenergy recovery from wastewater treatment under various PEMs, while application of PEM N-115 produced the best performance compared to PEMs N-212 and N-117 and those in previous studies of membrane/membrane-less air-cathode single-chamber MFCs that consumed dye wastewater.

Matched MeSH terms: Oxygen/chemistry
Impacts of pig farming on the water quality of Serin River, Sarawak

Ling T, Layang H, Then Y, Apun K

Sains Malaysiana, 2006;35:45-50.

In Sarawak, pig farm operators are required to treat the wastewater containing pig waste and spilt food in oxidation ponds before discharge. However, information on the impact of this industry on surface water quality is lacking. Therefore, the objective of this study is to determine the impact of pig farm effluent on the water quality of Serin River and its tributaries. Results of analysis show that the tributary that received pond effluent has significantly higher mean of total suspended solids (TSS), biochemical oxygen demand (BOD5) chemical oxygen demand (COD), ammonia-nitrogen (NH3 -N), reactive phosphorus (SRP) and Escherichia coli (E. coli) concentrations when compared to those of the tributary that did not receive pond effluent. Comparisons between the stations upstream and downstream of the discharge point indicated that BOD5 and COD were significantly higher at the downstream station that received pond effluent. Dissolved oxygen (DO) was the lowest at the tributary receiving effluent from pig farms with a mean of 2.40 mg/l. According to the Interim Water Quality Standard of the Department of Environment, water quality at the tributary that received pig farm effluent falls into Class III whereas that of the other stations falls into Class II. It is recommended that further studies be conducted on the management of waste to explore the possibility of turning the waste into a resource so that water quality of rivers can remain pristine for drinking and recreation.

Matched MeSH terms: Oxygen; Biological Oxygen Demand Analysis

Filters

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

External Links