Rates and causes of readmissions following index admissions for Takotsubo syndrome-a meta-analysis of 118,941 index hospitalizations

Background

Rising trends in takotsubo syndrome (TTS)-related complications warrant data to identify the rate, causes and predictors of readmission on a large scale. We conducted the first-ever meta-analysis to evaluate the pooled rate of short-term and long-term readmissions after index TTS admissions.

Methods

PubMed/Medline, EMBASE and SCOPUS databases were systematically reviewed to find studies through October 2019 reporting rates and causes of readmission following index TTS admissions. Random effects models were used to estimate pooled rates and causes of readmissions and I2 statistics were used to report inter-study heterogeneity.

Results

A total of 16 cohorts with 118,941 TTS index admissions (mean age 65–75 yrs; female >85%, median follow-up 272.5 days) revealed a 16.6% [95% CI-13.2%-20.3%, I2=99%] pooled rate of readmission. Short-term and long-term pooled readmission rates are displayed in Fig.1. The readmission rate was higher in cohorts with young patients (<70 vs. >70 yrs), smaller sample size (n<100 vs. n>100) and single-centres vs. multicentres. Studies published from the USA (16.4% vs. 14.9%) had a higher readmission rate as compared to Italy. The most frequent causes were cardiac (40.6%), respiratory (15.7%) and renal (7.0%). Among readmissions with cardiac diagnoses, heart failure was most common (40.1%).

Conclusions

This global meta-analysis revealed that the pooled rate of readmission following index TTS admissions was ∼17% and causes were mainly cardiac or respiratory.

Funding Acknowledgement

Type of funding source: None

A review on valorization of spent coffee grounds (SCG) towards biopolymers and biocatalysts production

Spent coffee grounds (SCG) are an important waste product millions of tons generated from coffee consumption and could be effectively utilized for various applications due to their high organic content. SCG can be used as a potential feedstock to develop coffee-based biorefinery towards value-added products generation through various biotechnological processes. Considerable developments have been reported on emerging SCG-based processes/products in various environmental fields such as removal of heavy metals and cationic dyes and in wastewater treatment. In addition, SCG are also utilized to produce biochar and biofuels. This review addressed the details of innovative processes used to produce polymers and catalysts from SCG. Moreover, the application of these developed products is provided and future directions of the circular economy for SCG utilization.

Adsorption, degradation, and mineralization of emerging pollutants (pharmaceuticals and agrochemicals) by nanostructures: a comprehensive review

This review discusses a fresh pool of research findings reported on the multiple roles played by metal-based, magnetic, graphene-type, chitosan-derived, and sonicated nanoparticles in the treatment of pharmaceutical- and agrochemical-contaminated waters. Some main points from this review are as follows: (i) there is an extensive number of nanoparticles with diverse physicochemical and morphological properties which have been synthesized and then assessed in their respective roles in the degradation and mineralization of many pharmaceuticals and agrochemicals, (ii) the exceptional removal efficiencies of graphene-based nanomaterials for different pharmaceuticals and agrochemicals molecules support arguably well a high potential of these nanomaterials for futuristic applications in remediating water pollution issues, (iii) the need for specific surface modifications and functionalization of parent nanostructures and the design of economically feasible production methods of such tunable nanomaterials tend to hinder their widespread applicability at this stage, (iv) supplementary research is also required to comprehensively elucidate the life cycle ecotoxicity characteristics and behaviors of each type of engineered nanostructures seeded for remediation of pharmaceuticals and agrochemicals in real contaminated media, and last but not the least, (v) real wastewaters are extremely complex in composition due to the mix of inorganic and organic species in different concentrations, and the presence of such mixed species have different radical scavenging effects on the sonocatalytic degradation and mineralization of pharmaceuticals and agrochemicals. Moreover, the formulation of viable full-scale implementation strategies and reactor configurations which can use multifunctional nanostructures for the effective remediation of pharmaceuticals and agrochemicals remains a major area of further research.

A brief review of anaerobic membrane bioreactors emphasizing recent advancements, fouling issues and future perspectives

This review summarizes the recent development and studies of anaerobic membrane bioreactor (AnMBR) to control fouling issues. AnMBR is an emerging waste water treatment technology mainly because of its low sludge residual, high volumetric organic removal rate, complete liquid-solid separation, better effluent quality, efficient resource recovery and the small footprint. This paper surveys the fundamental aspects of AnMBRs, including its applications, membrane configurations, and recent progress for enhanced reactor performance. Furthermore, the membrane fouling, a major restriction in the practical application of AnMBR, its mechanism and antifouling strategies like membrane cleaning, quorum quenching, ultrasonic treatment, membrane modifications, and antifouling agents are briefly discussed. Based on the review, the key issues that require urgent attention to facilitate large scale and integrated application of AnMBR technology are identified and future research perspectives relating to the prevalent issues are proposed.

Review on the production of medium and small chain fatty acids through waste valorization and CO2 fixation

The developing approaches in the recovery of resources from biowastes for the production of renewable value-added products and fuels, using microbial cultures as bio-catalyst have now became promising aspect. In the path of anaerobic digestion, the microorganisms are assisting transformation of a complex organic feedstock/waste to biomass and biogas. This potentiality consequently leads to the production of intermediate precursors of renewable value-added products. Particularly, a set of anaerobic pathways in the fermentation process, yields small-chain fatty acids (SCFA), and medium-chain fatty acids (MCFA) via chain elongation pathways from waste valorization and CO₂ fixation. This review focuses on the production of SCFA and MCFA from CO₂, synthetic substrates and waste materials. Moreover, the review introduces the metabolic engineering of Escherichia coli and Saccharomyces cerevisiae for SCFAs/MCFAs production. Furtherly, it concludes that future critical research might target progress of this promising approach as a valorization of complex organic wastes.

Review on sustainable production of biochar through hydrothermal liquefaction: Physico-chemical properties and applications

This review examines in detail the production and characteristics of biochar resulting from hydrothermal liquefaction. Specifically, the impact of feedstocks and different process parameters on the properties and yield of biochar by hydrothermal liquefaction has been thoroughly studied. Hydrothermal liquefaction derived biochars, relative to biochars from high-temperature thermochemical processes retain critical functional groups during carbonization and are therefore promising for a wide range of applications. Most of the review's efforts are to study possible hydrothermal liquefaction biochar applications in various fields, including fuel, metal and dye adsorption, pollutant reduction, animal feed, and biogas catalyst. The feasibility of biochar through the hydrothermal liquefaction process has been analysed via life-cycle assessment and energy evaluation. The article concludes with a brief discussion on possible issues and strategies for the sustainable development of hydrothermal liquefaction-based biochar.

Immobilized ZnO nano film impelled bacterial disintegration of dairy sludge to enrich anaerobic digestion for profitable bioenergy production: Energetic and economic analysis

Proper treatment and disposal of sludge is a substantial task around the biosphere. To address this issue, sludge deflocculation using photocatalyst was opted to enhance bacterial disintegration which in turn accelerate sludge digestion anaerobically. During this investigation, Direct current (DC) sputtering together with annealing process was used to immobilize Zinc oxide (ZnO). This immobilized ZnO removes the extracellular components at 15 min. The deflocculation mediated bacterial pretreatment induced 22.9% of soluble organics solubilization which auguments the biodegradability to 0.195 g COD/g COD during anaerobic digestion. The quantity of methane generated by deflocculated sludge was 39.2% higher than sludge with bacterial disintegration only with maximum methane yield of 437.14 mL/g COD. Hence, the outcome of the proposed work confirmed that the method is scalable with a net profit of 27 USD with the maximum methane generation of 413.1 kWh. Additionally, this method reduced 57% of dry sludge (solid).

Application of molecular techniques in biohydrogen production as a clean fuel

Considering the future energy demand and pollution to the environment, biohydrogen, a biofuel, produced from biological sources have garnered increased attention. The present review emphasis the various techniques and methods employed to enumerate the microbial community and enhancement of hydrogen production by dark fermentation. Notably, molecular techniques such as terminal restriction fragment length polymorphism (T-RFLP), quantitative real-time PCR (q-PCR), fluorescent in-situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), ribosomal intergenic spacer analysis (RISA), and next generation sequencing (NGS) have been extensively discussed on identifying the microbial population in hydrogen production. Further, challenges and merits of the molecular techniques have been elaborated.

Impervious and influence in the liquid fuel production from municipal plastic waste through thermo-chemical biomass conversion technologies - A review

Plastic waste is an environmental burden substance, which poses a high threat to the society during disposal. Rather than disposal, recycling of this waste to liquid fuel gains importance owing to its high utility. Among various techniques, thermo-chemical recycling techniques hold more benefits in generating high value added liquid fuels. In this review, the details of municipal plastic waste generation are provided with a brief description of the plastic waste management option and importance of recycling is explained. The overview of the thermo-chemical treatment focusing on the pyrolysis, gasification and hydrocracking process was elaborated. Catalysts mediated pyrolysis have wide-open their prospective for the generation of bio-oil, hydrocarbons, syngas and deterioration of undesired substances. Generally, advance development of enthusiastic catalysts for the synthesis of bio-oil would be vital for scaling up the pyrolysis process to succeed in commercial manufacture of biofuels from waste plastics. Overall rate treatment depends on operating parameter which determines the process efficiency and product yield. Hence, critical assessment of various parameter that has remarkable effect in the thermo-chemical treatment process was documented in detail. Moreover, endorsements of liquid fuel production, economic viability, and energy requirement of the treatment process, were delivered to attain effectual plastic wastes management.

Cost effective biomethanation via surfactant coupled ultrasonic liquefaction of mixed microalgal biomass harvested from open raceway pond

The present study aimed to enhance the biomethanation potential of mixed microalgae via cost effective surfactant coupled ultrasonic homogenization (SCUH). Mixed microalgae biomass was harvested using a coagulant (Alum) from a raceway pond. The harvested algal biomass was subjected to ultrasonic homogenization (UH) by varying the power from 100 to 180 W. A maximal soluble organic release of 2131 mg/L was achieved at an ultrasonic input energy (UIE) of 25200 kJ/kg TS. In order to enhance soluble organic release and to reduce energy spent, the optimized condition of ultrasonic pretreatment was coupled with varying sodium dodecyl sulphate (SDS) dosage. A higher solubilization of 30.5% was achieved at a UIE of 4200 kJ/kg SS with surfactant dosage of 0.02 g SDS/g SS for SCUH. SCUH showed higher methane production of 358 mL/g COD when compared to UH (185.9 mL/g COD), SCUH was economically feasible than UH.

Comparative evaluation of biochemical methane potential of various types of Ugandan agricultural biomass following soaking aqueous ammonia pretreatment

The feasibility of pretreatment involving soaking in aqueous ammonia (SAA) for the anaerobic digestion (AD) of eight different types of agricultural biomass of Ugandan origin was investigated. Moderate pretreatment temperatures of 60 and 90 °C were employed, and the NH₃ concentration, solid-to-liquid ratio, and pretreatment time were fixed at 15.0% (w/w), 1:6, and 6 h, respectively. The delignification efficiencies of the SAA pretreatment ranged from 51.1 to 76.6%, and the maximum value was observed for maize bran pretreated at 90 °C. Biochemical methane potential experiments proved that the breaking of the complex bonds of lignin made fermentable sugars easily accessible to microorganisms. In all cases, the SAA pretreatment enhanced the methane potential of the eight types of Ugandan biomass compared with its untreated counterparts. The pretreated maize bran exhibited the highest methane yield of 291.5 mL CH₄/g COD, which is 83.1% of the theoretical conversion. SAA followed by AD is useful for employing Ugandan agricultural biomass as a renewable energy source.

Application of chemo thermal coupled sonic homogenization of marine macroalgal biomass for energy efficient volatile fatty acid recovery

The present study aimed to employ energy efficient chemo thermal coupled sonic homogenization (CTSH) to obtain VFA from marine macroalgal hydrolysate, (Ulva fasciata). At first, chemo thermal homogenization (CTH) was applied on macroalgal biomass by adjusting the temperature, pH and treatment time from 60 to 90 ℃, 4-7 and 0-60 min, respectively. A higher organic matter solubilisation of 11.81% was obtained at an optimum pH of 6 at a temperature of 80 ℃ with 40 min of homogenization time. The results of CTSH implied that a higher organic matter solubilization of 26.4% was achieved by combined CTSH (sonic power & treatment time - 140 W & 14 min treatment time). CTSH considerably doubles the liquefaction in comparison with CTH. Based on OMS grouping, achieving 25% was sufficient for VFA production (2172.09 mg/L) and considered as economically feasible with net cost of 97.17 USD/ton of macroalgae.

Microalgae based biorefinery promoting circular bioeconomy-techno economic and life-cycle analysis

Microalgae are source of third generation biofuel having the key advantage of high lipid productivity. In recent times, biorefinery is seen as promising option to further reduce the production cost of microalgae biofuel. However, exact energy balance analysis has not been performed on important biorefinery routes. In this aspect, three biorefinery routes, all based on lipid based biorefinery route are evaluated for economical production of microalgal biofuel and valorised products. Biorefinery route 1 involves production of biodiesel, pigments, and animal feed. Biorefinery route 2 involves biogas and pigments production and two stage fermentation, and third biorefinery route involves bio-hydrogen and pigments production. Finally, the technoeconomic assessment of three biorefinery routes were reviewed, net energy savings, and life-cycle costing approaches to economize microalgal biorefinery are suggested.

A novel energetically efficient combinative microwave pretreatment for achieving profitable hydrogen production from marine macro algae (Ulva reticulate)

This study aims to enhance the hydrogen (H₂) production from marine macro algae (Ulva Reticulate) by microwave combined with hydrogen peroxide (H₂O₂) under alkaline condition. Microwave (domestic type) (M) pretreatment of algal biomass at its optimal power (40%) resulted in 27.9% COD solubilization at 15 min time interval. When this optimal microwave power was combined with H₂O₂ (MH) an increment in COD solubilization was achieved at 24 mg H₂O₂/g macroalgae dosage. Under alkaline condition (pH 7-12), microwave and H₂O₂ combination (MHA) yielded better result than MH. At optimal alkaline condition (pH 10), MHA pretreatment shows a COD solubilization of 34%. Microwave in alkaline condition induces decomposition of H₂O₂ and more OH radical synthesis. This synergistically promotes solubilization. The MHA process considerably diminish time and specific energy required for biomass disintegration. Among the samples, highest H₂ yield of 87.5 mL H₂/g COD was observed for MHA.

Biorefinery of spent coffee grounds waste: Viable pathway towards circular bioeconomy

The circular bioeconomy plan is an innovative research based scheme intended for augmenting the complete utilization and management of bio-based resources in a sustainable biorefinery route. Spent coffee grounds based biorefinery is the emerging aspect promoting circular bioeconomy. The sustainable circular bioeconomy by utilizing SCG is achieved by cascade approaches and the inclusion of many biorefinery approaches to obtain many bio-products. The maximum energy recovery can be obtained by process integration. The economic analysis of the biofuel production from SCG is dependent on the cost of raw material, transportation, the need of labor and energy, oil extraction operations and biofuel production. The inclusion of new products from already established product can minimize the investment cost when related to the production cost. A positive net present value can be achieved via SCG biorefinery which indicates the profitability of the process.

Immunological biomarkers in neuropsychiatric systemic lupus erythematosus: a comparative cross-sectional study from a tertiary care center in South India

INTRODUCTION

The prevalence of various immunological biomarkers in neuropsychiatric systemic lupus erythematosus (NPSLE) differs among various patients with varied neuropsychiatric manifestations and different populations. We studied the prevalence of these biomarkers; especially the neuron specific autoantibodies in patients with systemic lupus erythematosus (SLE) and compared them among patients with and without neuropsychiatric involvement.

METHODOLOGY

This is a comparative cross-sectional study conducted in a tertiary care hospital in South India. The prevalence of immunological biomarkers including complement levels, systemic and brain specific autoantibodies (anti-myelin antibody, anti-myelin oligodendrocyte glycoprotein and anti-myelin-associated glycoprotein antibody) were assessed and compared among those with and without NPSLE and with different NPSLE manifestations.

RESULTS

A total of 522 SLE patients were enrolled in the study. The mean age of the study participants was 28.5 ± 8.8 years and 93.5% were women. Neuropsychiatric manifestations were seen in 167 (32%) patients. Seizure was the most common neuropsychiatric manifestation seen in 41.3%, followed by psychosis (18.6%), mood disorder (16.8%), stroke (10.8%), mononeuropathy (10.2%), headache (9.6%), acute confusional state (6.6%) and aseptic meningitis (5.4%). Patients with NPSLE had a higher SLE disease activity index score. Most of the autoantibodies, that is anticardiolipin antibody (aCL), anti-β2 glycoprotein 1 antibody (β2GP1), lupus anticoagulant (LA), anti-nucleosome, anti-ribosomal P, anti-Ro52, anti-Ro60 and anti-La, were seen in higher proportion in the NPSLE group, although the difference failed to reach statistical significance. On subgroup analysis, psychosis was significantly higher in patients with anti-ribosomal P positivity than without (11.8% versus 4.1%, p.0.007; odds ratio (OR) 3.1, confidence interval (CI) 1.4-6.8), while stroke had a higher proportion among those with positive b2GP1 IgG (6.3% versus 1.8%, p.0.03; OR 3.6, CI 1.2-11.0). A higher proportion of demyelination was seen among the LA positive than the negative (10.3% versus 0.2%, p.0.03; OR 5.39, CI 1.15-24.17) and anti-myelin oligodendrocyte glycoprotein in mood disorder (14.3% versus 3.4%, p = 0.03; OR 4.66, CI 1.13-19.13).

CONCLUSION

No single biomarker correlated with NPSLE. Among different NPSLE manifestations, the prevalence of IgG β2GP1 in stroke, LA in demyelination, anti-ribosomal P in psychosis and anti-myelin oligodendrocyte glycoprotein in mood disorder were higher. Further studies on the pathogenic mechanisms underlying NPSLE and its different manifestations may help us to identify better biomarkers.

Biohythane production from food processing wastes - Challenges and perspectives

The food industry generates enormous quantity of food waste (FW) either directly or indirectly including the processing sector, which turned into biofuels for waste remediation. Six types of food processing wastes (FPW) such as oil, fruit and vegetable, dairy, brewery, livestock and finally agriculture based materials that get treated via dark fermentation/anaerobic digestion has been discussed. Production of both hydrogen and methane is daunting for oil, fruit and vegetable processing wastes because of the presence of polyphenols and essential oils. Moreover, acidic pH and high protein are the reasons for increased concentration of ammonia and accumulation of volatile fatty acids in FPW, especially in dairy, brewery, and livestock waste streams. Moreover, the review brought to forefront the enhancing methods, (pretreatment and co-digestion) operational, and environmental parameters that can influence the production of biohythane. Finally, the nature of feedstock's role in achieving successful circular bio economy is also highlighted.

Industrial wastewater to biohydrogen: Possibilities towards successful biorefinery route

The aim of this review is to summarize the modern developments and enhancement strategies reported for improving the biorefinery route of industrial wastewater to biohydrogen. Recent developments towards biohydrogen production chiefly involves culture enrichment, pretreatment of biocatalysts, co culture fermentation, metabolic and genetic engineering, ecobiotechnological approaches and the coupling process of biohydrogen. In addition, an overview of dark fermentation, pathways involved, microbes involved in biohydrogen production, industrial wastewater as substrate have been focused. The utilization of organic residuals of dark fermentation for subsequent value added products are highlighted. More apparently, the two stage coupling process and its possibilities towards biorefinery has been reviewed comprehensively. Moreover, comparative energy and economic aspects of biohydrogen production from industrial wastewater and its prospects towards pilot scale applications are also spotlighted. Though all the enhancement strategies have both benefits and disadvantages, coupling process is considered as the most successful biorefinery route for biohydrogen production.

Polyhydroxy butyrate production by Acinetobacter junii BP25, Aeromonas hydrophila ATCC 7966, and their co-culture using a feast and famine strategy

The study aimed to evaluate biopolymer production using two bacterial strains, Acinetobacter junii BP25 and Aeromonas hydrophila ATCC 7966, and their co-culture. Batch experiments were evaluated using acetate and butyrate as carbon sources in feast and famine strategy. Feast phase was studied using carbon, nitrates and phosphate in the ratio of 100:8:1 and famine phase was limited with the phosphate and nitrates. Co-culture resulted in highest specific growth rate (0.30 h^-1) in the feast phase and the famine phase accounted the maximum polyhydroxybutyrate (PHB) accumulation (2.46 g PHB/L), followed by Acinetobacter junii BP25 (0.25 h^-1 and 1.82 g PHB/L) and Aeromonas hydrophila ATCC 7966 (0.17 h^-1 and 1.12 g PHB/L). Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR) structural analysis confirmed as PHB. PHB production using the co-culture could be integrated with biohydrogen process using volatile fatty acids (VFA) as a carbon source in the biorefinery framework.

The effect of an intraorifice barrier and base under coronal restorations on the healing of apical periodontitis: a randomized controlled trial

AIM

To evaluate the effect of intraorifice barriers and bases on the healing of apical periodontitis following root canal treatment in mandibular molars.

METHODOLOGY

A total of 120 permanent mandibular molars with necrotic pulps and periapical radiolucencies (PAI score ≥ 3) were recruited. Root canal treatment was performed in all teeth using a standard protocol, following which they were randomly allocated to one of the three treatment groups: intraorifice barrier group: coronal 3-mm gutta-percha was removed and replaced with glass-ionomer cement (GIC) barrier. The floor of the pulp chamber was then sealed with 2-mm-thick GIC base followed by final composite resin restoration; base group: received 2-mm-thick GIC base before placement of composite resin restoration; and control group: had pulp chamber entirely filled with composite resin only. Follow-up was done at 3, 6, 9 and 12 months. Combination of clinical and radiographic parameters were used to assess treatment outcome. The data were analysed using Kruskal-Wallis, chi-square and Wilcoxon signed-rank tests and logistic regression analysis.

RESULTS

At the end of 12 months, the base group had the most favourable healing (97.1%), whilst the control group had the least favourable healing (83.8%). The intraorifice barrier group had healing of 92.1%. However, there was no significant difference in healing between groups at the end of the follow-up period (P > 0.05). Additional subgroup analysis revealed a nonsignificant effect of periodontal status and root filling level on periapical healing.

CONCLUSION

The use of an additional barrier under permanent restorations did not significantly improve the outcome of primary root canal treatment in posterior teeth after 12 months. However, its influence in the long term requires further evaluation.

Nanoparticle induced biological disintegration: A new phase separated pretreatment strategy on microalgal biomass for profitable biomethane recovery

This study involves the application of new phase separated biological pretreatment (PSBP) strategy on microalgal biomass using the nickel nanoparticle induced cellulase secreting bacterial disintegration. Particularly, interest was focussed on cell wall weakening (CWW) of microalgae biomass besides the cell disintegration (CD) and release of organics. During CWW, protein, carbohydrate, cellulose, hemicellulose and DNA were used as evaluation indexes. Similarly, during CD, soluble chemical oxygen demand was used as evaluation index to assess the disintegration effect. A higher CWW was achieved at nickel nanoparticle (Np) dosage of 0.004 g/g SS. During CD, a clear demarcation in biomass solubilisation was achieved by PSBP (36%) than the sole biological pretreatment -BP (24%). The biomethanogenesis test results showed that enhanced methane production of 411 mL/g COD was achieved by PSBP than BP. Energy analysis showed that a higher net energy production of 6.467 GJ/d was achieved by PSBP.

A review on biopolymer production via lignin valorization

Lignin based biopolymer (value added products) production is the most promising technology in the perspective of lignin valorization and sustainable development. Valorization of lignin gain the potentials to produce biopolymers such as polyhydroxyalkanoates, polyhydroxybutyrates, polyurethane etc. However, lignin valorization processes still needs development due to the recalcitrant nature of lignin which restricts its potential to produce valuable products. Many novel extraction strategies have been developed to fragment the lignin structure and make ease the recovery of valuable products. Achieving in depth insights on lignin characteristics and structure will help to understand the metabolic and catalytic degradative pathways needed for lignin valorization. In the view of multipurpose characteristics of lignin for biopolymer production, this review will spot light the potential applications of lignin and lignin based derivatives on biopolymer production, various lignin separation technologies, lignin depolymerization process, biopolymers production strategies and the challenges in lignin valorization will be addressed and discussed.

A review on the conversion of volatile fatty acids to polyhydroxyalkanoates using dark fermentative effluents from hydrogen production

The production of bio/microbial-based polymers, polyhydroxyalkanoates (PHAs) from volatile fatty acids (VFAs) of dark fermentative effluents in the bio-H₂ reactor is being paid attention, owing to their commercial demand, applications and as carbon as well as energy storage source. Since, they are the cheap precursors for such valuable renewable biopolymers which all possess the properties; those are analogous to the petro-derived plastics. Several studies were stated, related to the consumption of both individual and mixed VFAs for the potential PHAs production. Their biodegradability nature makes them extremely desirable alternative to fossil-derived synthetic polymers. In this regard, this review summarizes the use of bio-based PHAs production via both microbial and biochemical pathways using dark fermentative bio-H₂ production from waste streams as feedstock. Furthermore, this review deals the characteristics, synthesis and production of the bio-based PHAs along with their co-polymers and applications to give an outlook on future research.

Diagnostic utility of fluorodeoxyglucose positron emission tomography in prosthetic joint infection based on MSIS criteria

AIMS

Prosthetic joint infection (PJI) and aseptic loosening in total hip arthroplasty (THA) can present with pain and osteolysis. The Musculoskeletal Infection Society (MSIS) has provided criteria for the diagnosis of PJI. The aim of our study was to analyze the utility of F18-fluorodeoxyglucose (FDG) positron emission tomography (PET) CT scan in the preoperative diagnosis of septic loosening in THA, based on the current MSIS definition of prosthetic joint infection.

PATIENTS AND METHODS

A total of 130 painful unilateral cemented THAs with a mean follow-up of 5.17 years (sd 1.12) were included in this prospective study. The mean patient age was 67.5 years (sd 4.85). Preoperative evaluation with inflammatory markers, aspiration, and an F18 FDG PET scan were performed. Diagnostic utility tests were also performed, based on the MSIS criteria for PJI and three samples positive on culture alone.

RESULTS

The mean erythrocyte sedimentation rate, C-reactive protein, and white cell count were 47.83 mm/hr, 25.21 mg/l, and 11.05 × 10⁹/l, respectively. The sensitivity, specificity, accuracy, negative predictive value, and false-positive rate of FDG PET compared with MSIS criteria were 94.87%, 38.46 %, 56.38%, 94.59 %, and 60.21%, respectively. The false-positive rate of FDG PET compared with culture alone was 77.4%.

CONCLUSION

FDG PET has a definitive role in the preoperative evaluation of suspected PJI. This the first study to evaluate its utility based on MSIS criteria and compare it with microbiology results alone. However, FDG PET has a high false-positive rate. Therefore, we suggest that F18 FDG PET is useful in confirming the absence of infection, but if positive, may not be confirmatory of PJI. Cite this article: Bone Joint J 2019;101-B:910-914.

Combination of microwave and gamma irradiation for reduction of aflatoxin B1 and microbiological contamination in peanuts (Arachis hypogaea L.)

Aflatoxin B1 (AFB1) is a natural carcinogen commonly present in food and feed which has deleterious effects on human and animal health. Combination treatment of microwave heating and gamma irradiation has been investigated. Artificially spiked peanuts (Arachis hypogaea L.) were used with a concentration of 300 μg/kg of AFB1 to evaluate the treatment efficacy. Qualitative and quantitative analysis of AFB1 was carried out by one dimensional thin layer chromatography and enzyme-linked immune-sorbent assay (ELISA), respectively. Gamma irradiation (5, 7 and 9 kGy) alone reduced 20 to 43% of AFB1, while, only low power microwave heating (360, 480 and 600 W) reduced it by 59 to 67%. The synergistic effect of a combination treatment at 7 and 9 kGy of irradiation at any of the chosen microwave power levels and sequence of treatment was able to reduce >95% in artificially spiked peanuts. Knowing the limitation of ELISA, an Ames test was employed to determine the mutagenicity of AFB1 in combination-treated (7 kGy and 600 W) artificially spiked peanut samples, resulting in an 80-85% reduction of its mutagenicity. Quality parameters of peanuts in terms of moisture content, water activity, hardness, colour, peroxide value and free fatty acid were evaluated and observed to be retained after combination treatments. Post-treatment sensory analysis in respect of appearance, colour, texture, taste, aftertaste and overall acceptability gave satisfactory scores. The microbiological safety of treated peanuts (exclusive and combination of 7 kGy and 360-600 W) was assessed in terms of total bacterial count, aerobic spore count, and yeast and mould count. The microbiological load was completely eliminated after exclusive gamma irradiation or the combination treatments. Combination treatment (7 kGy and 600 W) demonstrated 71 to 87% reduction in AFB1 from naturally contaminated peanuts and is recommended for further commercial application.

Anaerobic membrane bioreactors for wastewater treatment: Novel configurations, fouling control and energy considerations

Water shortage, public health and environmental protection are key motives to treat wastewater. The widespread adoption of wastewater as a resource depends upon development of an energy-efficient technology. Anaerobic membrane bioreactor (AnMBR) technology has gained increasing popularity due to their ability to offset the disadvantages of conventional treatment technologies. However there are several hurdles, yet to climb over, for wider spread and scale-up of the technology. This paper reviews fundamental aspects of anaerobic digestion of wastewater, and identifies the challenges and opportunities to the further development of AnMBRs. Membrane fouling and its implications are discussed, and strategies to control membrane fouling are proposed. Novel AnMBR configurations are discussed as an integrated approach to overcome technology limitations. Energy demand and recovery in AnMBRs is analyzed. Finally key issues that require urgent attention to facilitate global penetration of AnMBR technology are highlighted.

A perspective on galactose-based fermentative hydrogen production from macroalgal biomass: Trends and opportunities

This review analyses the relevant studies which focused on hydrogen synthesis by dark fermentation of galactose from macroalgal biomass by discussing the inoculum-related pretreatments, batch fermentation and inhibition, continuous fermentation systems, bioreactor designs for continuous operation and ionic liquid-assisted catalysis. The potential for process development is also revisited and the challenges towards suppressing glucose dominance over a galactose-based hydrogen production system are presented. The key challenges in the pretreatment process aiming to achieve a maximum recovery of upgradable (fermentable) sugars from the hydrolysates and promoting the concomitant detoxification of the hydrolysates have also been highlighted. The research avenues for bioprocess intensification connected to enhance selective sugar recovery and effective detoxification constitute the critical steps to develop future red macroalgae-derived galactose-based robust biohydrogen production system.

Biofouling of membranes in microbial electrochemical technologies: Causes, characterization methods and mitigation strategies

The scope of the review is to discuss the current state of knowledge and lessons learned on biofouling of membrane separators being used for microbial electrochemical technologies (MET). It is illustrated what crucial membrane features have to be considered and how these affect the MET performance, paying particular attention to membrane biofouling. The complexity of the phenomena was demonstrated and thereby, it is shown that membrane qualities related to its surface and inherent material features significantly influence (and can be influenced by) the biofouling process. Applicable methods for assessment of membrane biofouling are highlighted, followed by the detailed literature evaluation. Finally, an outlook on e.g. possible mitigation strategies for membrane biofouling in MET is provided.

Microbiome involved in anaerobic hydrogen producing granules: A mini review

This mini review overviewed the latest updates on the anaerobic hydrogen fermentation using the granulation technology and the microbiome involved in the process. Additionally, the implication of various reactor design and their microbial changes were compared and provided the new insights on the role of microbiomes for rapid granules formation and long term stable operation in a continuous mode operation. The information provided in this communication would help to understand the key role of microbiomes and their importance in anaerobic hydrogen producing granular systems.

Developments in biochar application for pesticide remediation: Current knowledge and future research directions

The indiscriminate use of pesticides due to modern agricultural practices has received special attention from the scientific community to address the persistence, recalcitrance and multi-faceted toxicity of several pesticides. Pesticides are hazardous/toxic and can accumulate easily into non-target organisms including humans and other life forms. Several studies have been performed to investigate the effect of biochar addition for pesticide remediation. This review provides a comprehensive information on biochar amendment for the remediation of persistent organic pollutants such as pesticides. The types of pesticides and their hazards to life forms are briefly introduced before detailing biochar production, its characteristics and applications. Biochar addition in pesticide polluted environment offers the following advantages: (a) increases the soil water holding capacity, (b) improves aeration conditions in soil, and (c) provides habitat for the growth of microorganisms, thereby facilitating microbial community for metabolic activities and pesticide degradation. This paper also provides an up-to-date review on remediation of pesticides using biochar, the knowledge gaps and the future research directions in this field to evaluate the effect of biochar addition on agricultural and environmental performances.

Effects of light intensity on biomass, carbohydrate and fatty acid compositions of three different mixed consortia from natural ecological water bodies

This study investigated the effect of light intensity on three various microalga consortia collected from natural ecological water bodies (named A, B and C) towards their fatty acid profiling and fractions, carbohydrate and protein production at different light intensities of 100, 200 and 300 μmol m^-2 s^-1. The results indicating that increasing light intensity positively correlated with the lipid production than carbohydrate and protein. Irrespective to the solids (Total and Volatile Solid) content, lipids and carbohydrate has varied significantly. Consortia C showed higher productivity toward lipids, whereas consortia A and B accumulated more carbohydrate and protein, respectively. The microscopic images revealed the breakdown of cells during the increase in light intensity, in spite, the similar algal species were observed in all consortia experimented. Principal component analysis (PCA) revealed that low light intensity aid relatively in high protein, Total Nitrogen and Total Phosphorus, meanwhile high intensity attributed carbohydrates and unsaturated fatty acids (USFA) contents.

A review on chemical mechanism of microalgae flocculation via polymers

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Mechanism involved in microalgal flocculation has been reviewed.

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Commercially, bioflocculation is suitable and cost-effective.

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Organic & inorganic flocculants and their features are covered.

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Ideal proportion amongst flocculants and biomass decides their efficiency.

Industrially, harvesting of the microalgal biomass is a techno-economic tailback, which essentially meant for the algal biomass industry. It is considered energy as well as cost-intensive in view of the fact that the dewatering process during harvesting. In this review chemical reactions involved in the flocculation of microalage biomass via various certain principal organic polymers are focused. Besides, it focuses on natural biopolymers as flocculants to harvest the cultivated microalgae. Commercially, bio-flocculation is suitable and cost-effective in the midst of a range of adopted harvesting techniques and the selection of an appropriate bioflocculant depends on its efficacy on the several microalgae strains like potential biomass fixation, ecological stride and non-perilous nature. The harvesting of toxin free microalgae biomass in large quantity by such flocculants can be considered to be one of the most cost-effective performances towards sustainable biomass recovery.

A review on lignin structure, pretreatments, fermentation reactions and biorefinery potential

In recent years, lignin valorization is commercially an important and advanced sustainable process for lignocellulosic biomass-based industries, primarily through the depolymerization path. The conversion of the lignin moieties into biofuels and other high value-added products are still challenging to the researchers due to the heterogeneity and complex structure of lignin-containing biomass. Besides, the involvement of different microorganisms that carries varying metabolic and enzymatic complex systems towards degradation and conversion of the lignin moieties also discussed. These microorganisms are frequently short of the traits which are obligatory for the industrial application to achieve maximum yields and productivity. This review mainly focuses on the current progress and developments in the pretreatment routes for enhancing lignin degradation and also assesses the liquid and gaseous biofuel production by fermentation, gasification and hybrid technologies along with the biorefinery schemes which involves the synthesis of high value-added chemicals, biochar and other valuable products.

A review of the innovative gas separation membrane bioreactor with mechanisms for integrated production and purification of biohydrogen

This review article focuses on an assessment of the innovative Gas Separation Membrane Bioreactor (GS-MBR), which is an emerging technology because of its potential for in-situ biohydrogen production and separation. The GS-MBR, as a special membrane bioreactor, enriches CO₂ directly from the headspace of the anaerobic H₂ fermentation process. CO₂ can be fed as a substrate to auxiliary photo-bioreactors to grow microalgae as a promising raw material for biocatalyzed, dark fermentative H₂-evolution. Overall, these features make the GS-MBR worthy of study. To the best of the authors' knowledge, the GS-MBR has not been studied in detail to date; hence, a comprehensive review of this topic will be useful to the scientific community.

Anaerobic membrane bioreactors for biohydrogen production: Recent developments, challenges and perspectives

Biohydrogen as one of the most appealing energy vector for the future represents attractive avenue in alternative energy research. Recently, variety of biohydrogen production pathways has been suggested to improve the key features of the process. Nevertheless, researches are still needed to overcome remaining barriers to practical applications such as low yields and production rates. Considering practicality aspects, this review emphasized on anaerobic membrane bioreactors (AnMBRs) for biological hydrogen production. Recent advances and emerging issues associated with biohydrogen generation in AnMBR technology are critically discussed. Several techniques are highlighted that are aimed at overcoming these barriers. Moreover, environmental and economical potentials along with future research perspectives are addressed to drive biohydrogen technology towards practicality and economical-feasibility.