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Journal of Environmental Management Apr 2024Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by... (Review)
Review
Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by advanced treatments of the fractions. The knowledge about the performance of the separators and the quality of the fractions is scattered because of many available techniques and large variability in digestate characteristics. We performed a systematic review and found 175 observations of full-scale solid-liquid separation of digestate. We identified 4 separator groups, 4 digestate classes based on substrate, and distinguished whether chemical conditioners were used. We confirmed the hypothesis that the dominant substrate can affect the efficiency of the digestate separation. Furthermore, the results showed that centrifuges separated significantly more dry matter and total P than screw presses. Use of chemical conditioners in combination with a centrifuge lowered the dry matter concentration in the liquid fraction by 30%. Screw presses consumed 4.5 times less energy than centrifuges and delivered 3.3 tonne ammonium N in the liquid fraction and 0.3 tonne total P in the solid fraction using 1 MWh. The results can provide data for systems analyses of biogas solutions and can support practitioners when choosing among full-scale separator techniques depending on the digestate type. In a broader perspective, this work contributes to the continuous improvement of biogas plants operations and to their role as nutrients recovery sites.
Topics: Anaerobiosis; Biofuels
PubMed: 38508011
DOI: 10.1016/j.jenvman.2024.120585 -
PloS One 2024Locomotor profiling using anaerobic speed reserve (ASR) enables insights into athletes' physiological and neuromuscular contributing factors and prescription of...
Assessing anaerobic speed reserve: A systematic review on the validity and reliability of methods to determine maximal aerobic speed and maximal sprinting speed in running-based sports.
PURPOSE
Locomotor profiling using anaerobic speed reserve (ASR) enables insights into athletes' physiological and neuromuscular contributing factors and prescription of high-intensity training beyond maximal aerobic speed (MAS). This systematic review aimed to determine the validity and reliability of different methods to assess the characteristics of ASR, i.e., MAS and maximal sprinting speed (MSS).
METHODS
A comprehensive search of the PubMed and Web of Science databases was conducted according to the PRISMA guidelines. Studies were included if they reported data on validity and/or reliability for methods to assess MAS or MSS.
RESULTS
58 studies were included with 28 studies referring to MAS and 30 studies to MSS. Regarding MAS, different methods for cardiopulmonary exercise testing yielded different values (four out of seven studies) of MAS (Cohen's d (ES) = 0.83-2.8; Pearson's r/intraclass correlation coefficient (r/ICC) = 0.46-0.85). Criterion validity of different field tests showed heterogeneous results (ES = 0-3.57; r/ICC = 0.40-0.96). Intraday and interday reliability was mostly acceptable for the investigated methods (ICC/r>0.76; CV<16.9%). Regarding MSS, radar and laser measurements (one out of one studies), timing gates (two out of two studies), and video analysis showed mostly good criterion validity (two out of two studies) (ES = 0.02-0.53; r/ICC = 0.93-0.98) and reliability (r/ICC>0.83; CV<2.43%). Criterion validity (ES = 0.02-7.11) and reliability (r/ICC = 0.14-0.97; CV = 0.7-9.77%) for global or local positioning systems (seven out of nine studies) and treadmill sprinting (one out of one studies) was not acceptable in most studies.
CONCLUSION
The criterion validity of incremental field tests or shuttle runs to examine MAS cannot be confirmed. Results on time trials indicate that distances adapted to the participants' sporting background, fitness, or sex might be suitable to estimate MAS. Regarding MSS, only sprints with radar or laser measures, timing gates, or video analysis provide valid and reliable results for linear sprints of 20 to 70 m.
Topics: Humans; Anaerobiosis; Reproducibility of Results; Athletes; Exercise; Running
PubMed: 38252665
DOI: 10.1371/journal.pone.0296866 -
Journal of Environmental Management Dec 2023Anaerobic digestion (AD) as a waste management strategy for the organic fraction of municipal waste (OFMSW) has received attention in developed countries for several...
Anaerobic digestion (AD) as a waste management strategy for the organic fraction of municipal waste (OFMSW) has received attention in developed countries for several decades, leading to the development of large-scale plants. In contrast, AD of OFMSW has only recently drawn attention in developing countries. This systematic review was carried out to investigate the implementation of AD to treat the OFMSW in developing countries, focusing on assessing pilot and full-scale AD plants reported in the last ten years. Studies that met the selection criteria were analyzed and data regarding operating parameters, feedstock characteristics, and biogas, digestate, and energy production were extracted. As outlined in this systematic review, AD plants located in developing countries are mostly one-stage mesophilic systems that treat OFMSW via mono-digestion, almost exclusively with the aim of producing electrical energy. Based on the analysis done throughout this systematic review, it was noted that there is a large difference in the maturity level of AD systems between developing and developed countries, mainly due to the economic capacity of developed countries to invest in sustainable waste management systems. However, the number of AD plants reported in scientific papers is significantly lower than the number of installed AD systems. Research articles regarding large-scale implementation of AD to treat OFMSW in developed countries were analyzed and compared with developing countries. This comparison identified practices used in plants in developed countries that could be utilized in the large-scale implementation and success of AD in developing countries. These practices include exploiting potential products with high market-values, forming partnerships with local industries to use industrial wastes as co-substrates, and exploring different biological and physical pretreatment technologies. Additionally, the analysis of capital and operational costs of AD plants showed that costs tend to be higher for developing countries due to their need to import of materials and equipment from developed countries. Technical, economical, and political challenges for the implementation of AD at a large-scale in developing countries are highlighted.
Topics: Solid Waste; Refuse Disposal; Anaerobiosis; Developing Countries; Bioreactors; Biofuels; Methane
PubMed: 37751665
DOI: 10.1016/j.jenvman.2023.118993 -
Revista Espanola de Quimioterapia :... Apr 2023The objective of this study was to perform a systematic review of the characteristics, causative microorganisms and outcome of brain abscesses caused by anaerobic...
The objective of this study was to perform a systematic review of the characteristics, causative microorganisms and outcome of brain abscesses caused by anaerobic bacteria over the past 25 years. We reviewed studies on brain abscesses which included infection due to anaerobic microorganisms published between 1998 and 2022. We excluded reports with polymicrobial infections (more than 2 anaerobic bacteria isolated) and those that do not provide enough information to make comparisons, the reports with only one case of brain abscess due to anaerobes, as well as those focused on an only anaerobic bacterium. Also, we have excluded the cases in pediatric population. We searched the scientific literature through the Cochrane Library, EMBASE and PubMed/MEDLINE databases for studies of this condition. We finally included 28 studies with 6,167 patients, of which 715 (11.5%) were cases caused by anaerobic bacteria. There was a male predominance (70%) and mean age of 40.3 years. Most infections were monomicrobial (59.4%). The most common anaerobic microorganisms isolated were Bacteroides spp (43.4%) and Gram-positive anaerobic cocci (35.1%). Cases of brain abscesses caused by anaerobic bacteria were most frequent in Asia and Europe. The source of infection most frequent was otogenic in 84.6% followed by a neurosurgery procedure infection in 23% of patients. The main symptom observed was headache in 95.6% of patients followed by fever (69.5%). Surgical treatment was performed in 48 % of patients and the percentage of patients in whom antibiotic treatment was applied range 88.8% to 100%. The main limitation of this review is the non-inclusion of studies published before of 1998 in which MALDI-TOF MS system had not been introduced in the majority of laboratories for routine identification. The patient rate with isolation of anaerobic bacteria in brain abscesses is low, but these data could be underestimated mainly due to the fastidious nature of these microorganisms and the difficulties in the identification of some anaerobes.
Topics: Humans; Male; Child; Adult; Female; Anaerobiosis; Base Composition; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Brain Abscess; Bacteria, Anaerobic; Gram-Positive Cocci
PubMed: 36733997
DOI: 10.37201/req/114.2022 -
Journal of the International Society of... Feb 2021The effects of sodium bicarbonate (NaHCO) on anaerobic and aerobic capacity are commonly acknowledged as unclear due to the contrasting evidence thus, the present study... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The effects of sodium bicarbonate (NaHCO) on anaerobic and aerobic capacity are commonly acknowledged as unclear due to the contrasting evidence thus, the present study analyzes the contribution of NaHCO to energy metabolism during exercise.
METHODS
Following a search through five databases, 17 studies were found to meet the inclusion criteria. Meta-analyses of standardized mean differences (SMDs) were performed using a random-effects model to determine the effects of NaHCO supplementation on energy metabolism. Subgroup meta-analyses were conducted for the anaerobic-based exercise (assessed by changes in pH, bicarbonate ion [HCO], base excess [BE] and blood lactate [BLa]) vs. aerobic-based exercise (assessed by changes in oxygen uptake [VO], carbon dioxide production [VCO], partial pressure of oxygen [PO] and partial pressure of carbon dioxide [PCO]).
RESULTS
The meta-analysis indicated that NaHCO ingestion improves pH (SMD = 1.38, 95% CI: 0.97 to 1.79, P < 0.001; I = 69%), HCO (SMD = 1.63, 95% CI: 1.10 to 2.17, P < 0.001; I = 80%), BE (SMD = 1.67, 95% CI: 1.16 to 2.19, P < 0.001, I = 77%), BLa (SMD = 0.72, 95% CI: 0.34 to 1.11, P < 0.001, I = 68%) and PCO (SMD = 0.51, 95% CI: 0.13 to 0.90, P = 0.009, I = 0%) but there were no differences between VO, VCO and PO compared with the placebo condition.
CONCLUSIONS
This meta-analysis has found that the anaerobic metabolism system (AnMS), especially the glycolytic but not the oxidative system during exercise is affected by ingestion of NaHCO. The ideal way is to ingest it is in a gelatin capsule in the acute mode and to use a dose of 0.3 g•kg body mass of NaHCO 90 min before the exercise in which energy is supplied by the glycolytic system.
Topics: Anaerobiosis; Bicarbonates; Carbon Dioxide; Energy Metabolism; Exercise; Humans; Hydrogen-Ion Concentration; Lactic Acid; Oxygen; Sodium Bicarbonate
PubMed: 33546730
DOI: 10.1186/s12970-021-00410-y -
Nutrients Aug 2020Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition... (Meta-Analysis)
Meta-Analysis
Beta-alanine supplementation (BA) has a positive impact on physical performance. However, evidence showing a benefit of this amino acid in aerobic-anaerobic transition zones is scarce and the results controversial. The aim of this systematic review and meta-analysis is to analyze the effects of BA supplementation on physical performance in aerobic-anaerobic transition zones. At the same time, the effect of different dosages and durations of BA supplementation were identified. The search was designed in accordance with the PRISMA guidelines for systematic reviews and meta-analyses and performed in Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2010 and 2020. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the Time Trial Test (TTT) and Time to Exhaustion (TTE) tests, the latter separated into the Limited Time Test (LTT) and Limited Distance Test (LDT). The analysis was carried out with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Nineteen studies were included in the systematic review and meta-analysis, revealing a small effect for time in the TTT (SMD, -0.36; 95% CI, -0.87-0.16; I = 59%; = 0.010), a small effect for LTT (SMD, 0.25; 95% CI, -0.01-0.51; I = 0%; = 0.53), and a large effect for LDT (SMD, 4.27; 95% CI, -0.25-8.79; I = 94%; = 0.00001). BA supplementation showed small effects on physical performance in aerobic-anaerobic transition zones. Evidence on acute supplementation is scarce (one study); therefore, exploration of acute supplementation with different dosages and formats on physical performance in aerobic-anaerobic transition zones is needed.
Topics: Aerobiosis; Anaerobiosis; Dietary Supplements; Humans; Physical Functional Performance; Sports Nutritional Physiological Phenomena; beta-Alanine
PubMed: 32824885
DOI: 10.3390/nu12092490 -
International Journal of Environmental... Jun 2020: There are many athletes who like to listen to music while making a high intensity effort. However, research into the effects of listening to music on athletic... (Meta-Analysis)
Meta-Analysis
: There are many athletes who like to listen to music while making a high intensity effort. However, research into the effects of listening to music on athletic performance has provided controversial results, and it is suggested that the timing and type of music might affect the anaerobic performance response. : The main aim of the current systematic review and meta-analysis was to analyze the effects while listening to music tasks via the 30 s Wingate anaerobic test (WAnT) on absolute performance and relative peak power (APP and RPP), absolute and relative mean power (AMP and RMP), and fatigue index (FI). : PRISMA guidelines were used as a basis for conducting this systematic review, with inclusion criteria being set out according to the PICOS model. Computer-based literature research was undertaken until 10 March 2020 using the following online databases: PubMed/Medline, WOS, Cochrane Library, and Scopus. The literature was reviewed with regard to the effects of listening to music on the WAnT using several music variables on: APP, RPP, AMP, RMP and FI. Hedges' g formula was used to calculate both standard mean differences and 95% confidence intervals, in order to establish continuous outcomes. Furthermore, the I statistic evaluated systematic differences (heterogeneity) together with a random effect meta-analysis model. : This systematic review included nine articles that researched into the effects of music on WAnT performance (six studies describe improvements in APP and/or RPP, four in AMP and/or RMP and three in FI). The random effects model was used to undertake a final meta-analysis, with standardized mean differences (SMD) and magnitude of standardized mean differences (MSMD) (Hedges' g) being pooled accordingly. The resulting meta-analysis incorporated eight studies that had been previously published, with results showing that there were no apparent beneficial effects on APP ( = 0.09), AMP ( = 0.33) and FI ( = 0.46) as a consequence of listening to music. However, listening to music showed beneficial effects on RPP (SMD: 0.65; 95%: CI 0.35 to 0.96; MSMD: moderate; I, 0%; < 0.001) and RMP (SMD: 1.03; 95%: CI, 0.63 to 1.42; MSMD: trivial; I, 0%; < 0.001). : This systematic review and meta-analysis has shown that listening to music during the WAnT might physiologically enhance relative anaerobic exercise performance, although reasons remain speculative.
Topics: Anaerobiosis; Auditory Perception; Exercise; Exercise Test; Fatigue; Humans; Music
PubMed: 32599941
DOI: 10.3390/ijerph17124564 -
Nutrients May 2020Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms.... (Meta-Analysis)
Meta-Analysis
Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms. However, research results have shown to be controversial. The great differences regarding required metabolic pathways and physiological demands between aerobic and anaerobic sport disciplines could be the reasons. The aim of this systematic review and meta-analysis was to evaluate the effects of Arg supplementation on aerobic (≤VOmax) and anaerobic (>VOmax) performance. Likewise, to show the effective dose and timing of this supplementation. A structured search was carried out in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and PICOS guidelines in PubMed/MEDLINE, Web of Science (WOS), and Scopus databases from inception to January 2020. Eighteen studies were included which compare Arg supplementation with placebo in an identical situation and testing its effects on aerobic and anaerobic performance tests. Trials analyzing supplementation with other supplements were removed and there was not athlete's level, gender, ethnicity, or age filters. The performed meta-analysis included 15 studies and random effects model and pooled standardized mean differences (SMD) were used according to Hedges' g. Results revealed that Arg supplementation could improve aerobic (SMD, 0.84; 95% CI, 0.12 to 1.56; magnitude of SMD (MSMD), large; I2, 89%; = 0.02) and anaerobic (SMD, 0.24; 95% CI, 0.05 to 0.43; MSMD, small; I2, 0%; = 0.01) performance tests. In conclusion, acute Arg supplementation protocols to improve aerobic and anaerobic performance should be adjusted to 0.15 g/kg of body weight ingested between 60-90 min before. Moreover, chronic Arg supplementation should include 1.5-2 g/day for 4-7 weeks in order to improve aerobic performance, and 10-12 g/day for 8 weeks to enhance anaerobic performance.
Topics: Aerobiosis; Anaerobiosis; Arginine; Athletic Performance; Body Weight; Dietary Supplements; Energy Metabolism; Female; Humans; Male; Nitric Oxide; Performance-Enhancing Substances
PubMed: 32370176
DOI: 10.3390/nu12051300 -
Frontiers in Medicine 2020(CD) is a spore-forming bacterium that causes life-threatening intestinal infections in humans. Although formerly regarded as exclusively nosocomial, there is...
Global and Historical Distribution of in the Human Diet (1981-2019): Systematic Review and Meta-Analysis of 21886 Samples Reveal Sources of Heterogeneity, High-Risk Foods, and Unexpected Higher Prevalence Toward the Tropic.
(CD) is a spore-forming bacterium that causes life-threatening intestinal infections in humans. Although formerly regarded as exclusively nosocomial, there is increasing genomic evidence that person-to-person transmission accounts for only <25% of cases, supporting the culture-based hypothesis that foods may be routine sources of CD-spore ingestion in humans. To synthesize the evidence on the risk of CD exposure via foods, we conducted a systematic review and meta-analysis of studies reporting the culture prevalence of CD in foods between January 1981 and November 2019. Meta-analyses, risk-ratio estimates, and meta-regression were used to estimate weighed-prevalence across studies and food types to identify laboratory and geographical sources of heterogeneity. In total, 21886 food samples were tested for CD between 1981 and 2019 (96.4%, = 21084, 2007-2019; 232 food-sample-sets; 79 studies; 25 countries). Culture methodology, sample size and type, region, and latitude were sources of heterogeneity ( < 0.05). Although non-strictly-anaerobic methods were reported in some studies, and we confirmed experimentally that improper anaerobiosis of media/sample-handling affects CD recovery in agar (Fisher, < 0.01), most studies (>72%) employed the same (one-of-six) culture strategy. Because the prevalence was also meta-analytically similar across six culture strategies reported, all studies were integrated using three meta-analytical methods. At the study level ( = 79), the four-decade global cumulative-prevalence of CD in the human diet was 4.1% (95%CI = -3.71, 11.91). At the food-set level ( = 232, mean 12.9 g/sample, similar across regions > 0.2; 95%CI = 9.7-16.2), the weighted prevalence ranged between 4.5% (95%CI = 3-6%; all studies) and 8% (95%CI = 7-8%; only CD-positive-studies). Risk-ratio ranking and meta-regression showed that milk was the least likely source of CD, while seafood, leafy green vegetables, pork, and poultry carried higher risks ( < 0.05). Across regions, the risk of CD in foods for foodborne exposure reproducibly decreased with Earth latitude ( < 0.001). In conclusion, CD in the human diet is a global non-random-source of foodborne exposure that occurs independently of laboratory culture methods, across regions, and at a variable level depending on food type and latitude. The latitudinal trend (high CD-food-prevalence toward tropic) is unexpectedly inverse to the epidemiological observations of CD-infections in humans (frequent in temperate regions). Findings suggest the plausible hypothesis that ecologically-richer microbiomes in the tropic might protect against intestinal CD colonization/infections despite CD ingestion.
PubMed: 32175321
DOI: 10.3389/fmed.2020.00009