Summary Background & aims Protein-Energy Wasting (PEW) is the depletion of protein/energy stores observed in the most advanced stages of Chronic Kidney Disease (CKD). PEW is highly prevalent among ...patients on chronic dialysis, and is associated with adverse clinical outcomes, high morbidity/mortality rates and increased healthcare costs. This narrative review was aimed at exploring the pathophysiology of PEW in end-stage renal disease (ESRD) on hemodialysis. The main aspects of nutritional status evaluation, intervention and monitoring in this clinical setting were described, as well as the current approaches for the prevention and treatment of ESRD-related PEW. Methods An exhaustive literature search was performed, in order to identify the relevant studies describing the epidemiology, pathogenesis, nutritional intervention and outcome of PEW in ESRD on hemodialysis. Results and conclusion The pathogenesis of PEW is multifactorial. Loss of appetite, reduced intake of nutrients and altered lean body mass anabolism/catabolism play a key role. Nutritional approach to PEW should be based on a careful and periodic assessment of nutritional status and on timely dietary counseling. When protein and energy intakes are reduced, nutritional supplementation by means of specific oral formulations administered during the hemodialysis session may be the first-step intervention, and represents a valid nutritional approach to PEW prevention and treatment since it is easy, effective and safe. Omega-3 fatty acids and fibers, now included in commercially available preparations for renal patients, could lend relevant added value to macronutrient supplementation. When oral supplementation fails, intradialytic parenteral nutrition can be implemented in selected patients.
Insulin resistance (IR) is a complex metabolic disorder that underlies several human diseases, including type 2 diabetes and cardiovascular disease. Despite extensive research, the precise mechanisms ...underlying IR development remain poorly understood. Previously we showed that deficiency of coenzyme Q (CoQ) is necessary and sufficient for IR in adipocytes and skeletal muscle (Fazakerley et al., 2018). Here, we provide new insights into the mechanistic connections between cellular alterations associated with IR, including increased ceramides, CoQ deficiency, mitochondrial dysfunction, and oxidative stress. We demonstrate that elevated levels of ceramide in the mitochondria of skeletal muscle cells result in CoQ depletion and loss of mitochondrial respiratory chain components, leading to mitochondrial dysfunction and IR. Further, decreasing mitochondrial ceramide levels in vitro and in animal models (mice, C57BL/6J) (under chow and high-fat diet) increased CoQ levels and was protective against IR. CoQ supplementation also rescued ceramide-associated IR. Examination of the mitochondrial proteome from human muscle biopsies revealed a strong correlation between the respirasome system and mitochondrial ceramide as key determinants of insulin sensitivity. Our findings highlight the mitochondrial ceramide-CoQ-respiratory chain nexus as a potential foundation of an IR pathway that may also play a critical role in other conditions associated with ceramide accumulation and mitochondrial dysfunction, such as heart failure, cancer, and aging. These insights may have important clinical implications for the development of novel therapeutic strategies for the treatment of IR and related metabolic disorders.
This paper presents a complete polarization model of a solid oxide fuel cell (SOFC) that eliminates the ambiguity of the suitability of such model when used under different design and operating ...conditions. The Butler–Volmer equation is used in the model to describe the activation overpotential instead of using simplified expressions such as the Tafel equation and the linear current–potential equation. In the concentration overpotential, both ordinary and Knudsen diffusions are considered to cater for different porous electrode designs. Sensitivity tests are then conducted to show the effect of the thickness of the respective fuel cell components on the drop in cell voltage. Results show that the performance of an anode-supported fuel cell is superior to that using cathode as the support under elevated operating pressure in the cathode compartment. The former can achieve an improved operating range of current density under normal atmospheric conditions.
Survivors of childhood, adolescent, and young adult (diagnosed when <25 years of age) cancer are at risk of mental health problems. The aim of this clinical practice guideline is to harmonise ...international recommendations for mental health surveillance in survivors of childhood, adolescent, and young adult cancer. This guideline was developed by a multidisciplinary panel of experts under the sponsorship of the International Guideline Harmonization Group. We evaluated concordance among existing survivorship clinical practice guidelines and conducted a systematic review following evidence-based methods. Of 7249 studies identified, 76 articles from 12 countries met the inclusion criteria. Recommendations were formulated on the basis of identified evidence in combination with clinical considerations. This international clinical practice guideline strongly recommends mental health surveillance for all survivors of childhood, adolescent, and young adult cancers at every follow-up visit and prompt referral to mental health specialists when problems are identified. Overall, the recommendations reflect the necessity of mental health surveillance as part of comprehensive survivor-focused health care.
ZnO:Co nanoclusters were synthesized by nanocluster-beam deposition with averaged particle size of 5
nm and porous structure, which were for the first time adopted to construct a novel amperometric ...glucose biosensor. Glucose oxidase was immobilized into the ZnO:Co nanocluster-assembled thin film through Nafion-assisted cross-linking technique. Due to the high specific active sites and high electrocatalytic activity of the ZnO:Co nanoclusters, the constructed glucose biosensor showed a high sensitivity of 13.3
μA/mA
cm
2. The low detection limit was estimated to be 20
μM (S/N
=
3) and the apparent Michaelis–Menten constant was found to be 21
mM, indicating the high affinity of the enzyme on ZnO:Co nanoclusters to glucose. The results show that the ZnO:Co nanocluster-assembled thin films with nanoporous structure and nanocrystallites have potential applications as platforms to immobilize enzyme in biosensors.
The contamination of microplastics in aquatic environment is regarded as a serious threat to ecosystem especially to aquatic environment. Microplastic pollution associated problems including their ...bioaccumulation and ecological risks have become a major concern of the public and scientific community. The removal of microplastics from their discharge points is an effective way to mitigate the adverse effects of microplastic pollution, hence has been the central of the research in this realm. Presently, most of the commonly used water or wastewater treatment technologies are capable of removing microplastic to certain extent, although they are not intentionally installed for this reason. Nevertheless, recognizing the adverse effects posed by microplastic pollution, more efforts are still desired to enhance the current microplastic removal technologies. With their structural multifunctionalities and flexibility, nanomaterials have been increasingly used for water and wastewater treatment to improve the treatment efficiency. Particularly, the unique features of nanomaterials have been harnessed in synthesizing high performance adsorbent and photocatalyst for microplastic removal from aqueous environment. This review looks into the potentials of nanomaterials in offering constructive solutions to resolve the bottlenecks and enhance the efficiencies of the existing materials used for microplastic removal. The current efforts and research direction of which studies can dedicate to improve microplastic removal from water environment with the augmentation of nanomaterial-enabled strategies are discussed. The progresses made to date have witnessed the benefits of harnessing the structural and dimensional advantages of nanomaterials to enhance the efficiency of existing microplastic treatment processes to achieve a more sustainable microplastic cleanup.
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•The potentials of nanomaterials for microplastic remediation are reviewed.•Various nanomaterial-enabled removal techniques are discussed.•Nanomaterials overcome the limitations of bulk materials in microplastic remediation.•The challenges and way forward are presented.
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•Thermodynamic comparative analysis of steam and dry reforming is evaluated.•Hydrogen formation from methane-ethane-glycerol steam and dry reforming is analysed.•Comparatively, ...methane-ethane-glycerol steam reforming produces more hydrogen.•Optimum hydrogen production at WMEG 3:1 and CMEG 1:1 at 1273 K.•Steam reforming reactions inhibits the carbon deposition thermodynamically.
Glycerol is produced as a by-product waste during the biodiesel manufacturing process. In recent researches, glycerol has been extensively studied for its potential to be converted into higher value-added compounds because it is renewable and bioavailable compound to reduce the high biodiesel production cost. As a result, various methods and technologies, such as steam reforming and dry reforming, were utilized to convert glycerol to higher value added products. The straightforward route of dry and steam reforming techniques uses carbon dioxide and other greenhouse gases to create added-value products like syngas, which may be considered renewable alternatives to fossil fuels as global CO2 emission issues get higher and near-uncontrollable. Therefore, this article presents a novel thermodynamic equilibrium analysis of steam and dry reforming with methane-ethane-glycerol mixture based on the total Gibbs free energy minimization method for hydrogen generation. Equilibrium product compositions were determined as a function of molar ratio between H2O/methane-ethane-glycerol (WMEG) from 1:1 to 12:1 and CO2/methane-ethane-glycerol (CMEG) from 1:1 to 12:1 for steam and dry reforming respectively, where the molar basis of the methane-ethane-glycerol mixture is 1:1:1. The reforming temperatures are ranged from 573 K to 1273 K at atmospheric pressure of 1 bar. The production trends of H2, CO, CO2, CH4 and C were compared between both reforming of glycerol. From to the result of the study, the optimal operating parameter for the highest hydrogen production was under steam reforming with WMEG of 3:1 at 1273 K and zero carbon deposition is achieved. In comparison with CO and CO2 production, dry reforming produced higher yields than steam reforming. Furthermore, a significant increment of hydrogen production was not observed at higher ratios of WMEG and CMEG. Steam reforming inhibited the carbon formation thermodynamically better than dry reforming.
Large scale application of solid sorbent for wastewater treatment have been barred with problems associated with its difficulty of filtration and adsorbent recovery from aqueous solution. The use of ...a solid support could eliminate these problems and offer better adsorption ability and reusability of the adsorbent. In this study, we have fabricated Fe-loaded chitosan (Fe-CS) film immobilized onto a glass support. The prepared Fe-CS film showed greater adsorption capacity of methyl orange (MO) by 22.5% as opposed to an unmodified CS film material. The adsorption isotherms, kinetics, thermodynamics, and reusability of the prepared adsorbent were investigated in detail. The adsorption profile under kinetic conditions adopted a best-fit according to the pseudo-second-order kinetic model, while the adsorption profiles equilibrium conditions were described by both the Langmuir and Temkin isotherm models. The trend for the maximum adsorption capacity (
q
m
) at variable temperature are listed: 97.1 (303 K), 102 (313 K) and 205 mg g
−1
(323 K). The binding mechanism of MO adsorption onto the immobilized Fe-CS film was by both electrostatic attractions and chelating interactions. As well, the findings of this study showed that the immobilized Fe-CS film is an effective adsorbent that can be easily recovered from treated water and recycled for multiple adsorption–desorption processes. The properties of the immobilized Fe-CS film demonstrate its excellent ability for the removal of MO dye or any similar pollutants.
To survey the demographics, risk factors, microbiology, and outcomes for infectious keratitis in Asia.
Prospective, nonrandomized clinical study.
Thirteen study centers and 30 sub-centers recruited ...consecutive subjects over 12-18 months, and performed standardized data collection. A microbiological protocol standardized the processing and reporting of all isolates. Treatment of the infectious keratitis was decided by the managing ophthalmologist. Subjects were observed for up to 6 months. Main outcome measures were final visual acuity and the need for surgery during infection.
A total of 6626 eyes of 6563 subjects were studied. The majority of subjects were male (n = 3992). Trauma (n = 2279, 34.7%) and contact lens wear (n = 704, 10.7%) were the commonest risk factors. Overall, bacterial keratitis was diagnosed in 2521 eyes (38.0%) and fungal keratitis in 2166 eyes (32.7%). Of the 2831 microorganisms isolated, the most common were Fusarium species (n = 518, 18.3%), Pseudomonas aeruginosa (n = 302, 10.7%), and Aspergillus flavus (n = 236, 8.3%). Cornea transplantation was performed in 628 eyes to manage ongoing infection, but 289 grafts (46%) had failed by the end of the study. Moderate visual impairment (Snellen vision less than 20/60) was documented in 3478 eyes (53.6%).
Demographic and risk factors for infection vary by country, but infections occur predominantly in male subjects and are frequently related to trauma. Overall, a similar percentage of bacterial and fungal infections were diagnosed in this study. Visual recovery after infectious keratitis is guarded, and corneal transplantation for active infection is associated with a high failure rate.
The sphingolipids galactosylceramide (GalCer), sulfatide (ST) and sphingomyelin (SM) are essential for myelin stability and function. GalCer and ST are synthesized mostly from C22‐C24 ceramides, ...generated by Ceramide Synthase 2 (CerS2). To clarify the requirement for C22‐C24 sphingolipid synthesis in myelin biosynthesis and stability, we generated mice lacking CerS2 specifically in myelinating cells (CerS2ΔO/ΔO). At 6 weeks of age, normal‐appearing myelin had formed in CerS2ΔO/ΔO mice, however there was a reduction in myelin thickness and the percentage of myelinated axons. Pronounced loss of C22‐C24 sphingolipids in myelin of CerS2ΔO/ΔO mice was compensated by greatly increased levels of C18 sphingolipids. A distinct microglial population expressing high levels of activation and phagocytic markers such as CD64, CD11c, MHC class II, and CD68 was apparent at 6 weeks of age in CerS2ΔO/ΔO mice, and had increased by 10 weeks. Increased staining for denatured myelin basic protein was also apparent in 6‐week‐old CerS2ΔO/ΔO mice. By 16 weeks, CerS2ΔO/ΔO mice showed pronounced myelin atrophy, motor deficits, and axon beading, a hallmark of axon stress. 90% of CerS2ΔO/ΔO mice died between 16 and 26 weeks of age. This study highlights the importance of sphingolipid acyl chain length for the structural integrity of myelin, demonstrating how a modest reduction in lipid chain length causes exposure of a denatured myelin protein epitope and expansion of phagocytic microglia, followed by axon pathology, myelin degeneration, and motor deficits. Understanding the molecular trigger for microglial activation should aid the development of therapeutics for demyelinating and neurodegenerative diseases.
Main Points
Oligodendrocytes lacking CerS2 produce myelin using sphingolipids with C16/C18 instead of C22/C24 N‐acyl chains.
C22/C24 myelin sphingolipids are essential for myelin stability, microglial quiescence, and survival beyond young adulthood.
