High Acid Load Research Articles

A magnetically separable SO4/Fe-Al-TiO2 solid acid catalyst for biodiesel production from waste cooking oil

A novel magnetic SO4/Fe-Al-TiO2 solid acid catalyst was synthesized for biodiesel production via the (trans)esterification of waste cooking oil (WCO). The nanocomposite catalyst was prepared by the sequential functionalisation of commercial rutile/anatase mixed phase TiO2 nanoparticles (NPs) with alumina as a buffer layer, and subsequently hematite to impart magnetic character, prior to sulfation with chlorosulfonic acid to introduce Brønsted acidity. XRD showed that the SO4/Fe-Al-TiO2 catalyst comprised titania (rutile and anatase phases), aluminium sulphate, and hematite nanoparticles, while electron microscopy revealed the layer-by-layer assembly of these components within the SO4/Fe-Al-TiO2 catalyst. FTIR confirmed the presence of surface sulphate groups SO42− and S2O72−/S3O102−, creating a predominantly Brønsted acid catalyst with high acid loading. The catalyst achieved 96% fatty acid methyl ester (FAME) yield from WCO after 2.5 h of reaction at 90 °C, using 3 wt% of the magnetic catalyst, and a methanol:oil molar ratio of 10:1. SO4/Fe-Al-TiO2 was also effective for feedstocks containing up to 20 wt% of free fatty acid (FFA), and showed excellent stability for WCO (trans)esterification over 10 recycles.

Effect of extraction conditions on citrate-mediated phosphorus removal and recovery from intercepted particulate runoff

Abstract Phosphorus (P) is a nonrenewable mineral resource that is critical to achieving food security for the growing world population. However, nearly half of total annual mined P is lost through nonpoint particulate runoff streams. Previously, we demonstrated inorganic phosphate extraction from runoff particulate mineral phases using P-solubilizing fungi (PSF) generating the organic acids citrate and oxalate. The objective of the current study was to investigate the effect of extraction process conditions on P extraction efficiency and kinetics from impounded urban storm water runoff sediments using citrate as the sole P solubilization agent. Abiotic extraction experiments were conducted according to a one-factor-at-a-time approach. High P removal and solubilization were favored at low sediment loading (5 g/100 mL), low initial pH (3), and high initial organic acid loading (75 mM), with P recovery efficiencies of 75% to 100% and 240 ppm solubilized phosphate levels achieved under these conditions. Initial and equilibrium extractant pH levels between citrate pK a1 (3.08) and pK a2 (4.74) appeared conducive for citrate ligand-induced particulate P release, possibly due to optimal balance of protonated and dissociated carboxylic groups. The results suggest that operating the extraction under fed-batch or semi-continuous modes with pH control can help maximize runoff particulate P recovery efficiency in PSF-mediated bioextractions wherein citric acid is the major fungal organic acid product.

Prediction of Renal Acid Load in Adult Patients on Parenteral Nutrition.

Metabolic acidosis and metabolic bone disease are frequent complications in patients on parenteral nutrition (PN). A common contributor to these complications could be a daily high renal acid load. This study aims to find a method for predicting the potential total acid load (PTAL) and the pH of the compounded parenteral nutrition mixtures. The pH and titratable acidity (TA) of fifty compounded mixtures were measured. The potential metabolic acid load (PMAL) was calculated by considering the amount of nutrients that are acid producers and consumers. The PTAL of the TPN mixtures was calculated by adding TA to PMAL. Multiple linear regression analyses were used to develop a predictive model for the TA and pH of the compounded mixtures. The predicted TA and pH values of the analyzed mixtures agreed with those measured (Passing-Bablok analysis). The PTAL was >50 mmol/day for 82% of the mixtures, >75 mmol/day for 40% of the mixtures, and >100 mmol/day for 22% of the mixtures. The prediction of the renal acid load in patients on long-term PN could allow more appropriate acid-base balancing. Moreover, predicting the pH of such mixtures could be useful to pharmacists to assess the stability and compatibility of the components in the compounded mixtures.

Alkaline Diet and Metabolic Acidosis: Practical Approaches to the Nutritional Management of Chronic Kidney Disease

The kidneys play an extremely important role in maintaining the body acid-base balance by excreting nonvolatile acids and regenerating and reabsorbing bicarbonate in the kidney tubules. As the individual loses their kidney function, renal excretion of nonvolatile acid produced by metabolism of the diet is impaired, resulting in low-grade metabolic acidosis. With this in mind, it is relevant to better understand the dietary aspects related to the acid-base balance in chronic kidney disease metabolic acidosis and try to provide possible strategies for the nutritional management of these cases. The type of diet can deeply affect the body by providing acid or base precursors. Generally speaking, foods such as meat, eggs, cheese, and grains increase the production of acid in the organism, whereas fruit and vegetables are alkalizing. On the other hand, milk is considered neutral as well as fats and sugars, which have a small effect on acid-base balance. The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products. Thus metabolic acidosis may be exacerbated by a contemporary Western diet, which delivers a high nonvolatile acid load. The remaining acid is neutralized or stored within the body. Bone and muscle are lost to neutralize the acid and serum bicarbonate falls. Early studies suggest that lowering the dietary acid load with a reduced protein content and vegetable proteins replacements, associated with an increase in fruits and vegetables intake can improve the metabolic parameters of acidosis, preserve bone and muscle, and slow the glomerular filtration rate decline. More studies focusing on the effects of controlled dietary interventions among chronic kidney disease patients are needed to determining the optimal target for nutritional therapy.

The Effect of Buffering High Acid Load Meal with Sodium Bicarbonate on Postprandial Glucose Metabolism in Humans-A Randomized Placebo-Controlled Study.

Background: High dietary acid load relates to increased risk of type 2 diabetes in epidemiological studies. We aimed to investigate whether buffering a high acid load meal with an alkalizing treatment changes glucose metabolism post meal. Methods: Non-diabetic participants (n = 32) were randomized to receive either 1680 mg NaHCO3 or placebo, followed by a high acid load meal in a double-blind placebo-controlled crossover (1–4 weeks apart) study. Thirty (20 men) participants completed the study. Venous blood pH, serum bicarbonate, blood glucose, serum insulin, C-peptide, non-esterified fatty acid (NEFA), and plasma glucagon-like peptide-1 (GLP-1) concentrations were measured at baseline (fasting) and at 15–30 min intervals for 3 h post meal. Results: The treatment was well tolerated. Venous blood pH declined in the first 15 min post meal with the placebo (p = 0.001), but not with NaHCO3 (p = 0.86) and remained decreased with the placebo for 3 h (pinteraction = 0.04). On average over the 3 h blood pH iAUC was greater with NaHCO3 compared with placebo (p = 0.02). However, postprandial glucose, insulin, C-peptide, NEFA and GLP-1 were not different between treatments (pinteraction ≥ 0.07). Conclusions: An alkalizing medication administered pre-meal has no acute effect on glycaemia and insulin response in healthy individuals. Long-term interventions in at-risk populations are necessary to investigate the effect of sustained alkalization on glucose metabolism.

Acid Load and Phosphorus Homeostasis in CKD

The kidneys maintain acid-base homeostasis through excretion of acid as either ammonium or as titratable acids that primarily use phosphate as a buffer. In chronic kidney disease (CKD), ammoniagenesis is impaired, promoting metabolic acidosis. Metabolic acidosis stimulates phosphaturic hormones, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) invitro, possibly to increase urine titratable acid buffers, but this has not been confirmed in humans. We hypothesized that higher acid load and acidosis would associate with altered phosphorus homeostasis, including higher urinary phosphorus excretion and serum PTH and FGF-23. Cross-sectional. 980 participants with CKD enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. Net acid excretion as measured in 24-hour urine, potential renal acid load (PRAL) estimatedfrom food frequency questionnaire responses, and serum bicarbonate concentration< 22 mEq/L. 24-hour urine phosphorus and calcium excretion and serum phosphorus, FGF-23, and PTH concentrations. Using linear and log-linear regression adjusted for demographics, kidney function, comorbid conditions, body mass index, diuretic use, and 24-hour urine creatinine excretion, we found that 24-hour urine phosphorus excretion was higher at higher net acid excretion, higher PRAL, and lower serum bicarbonate concentration (each P<0.05). Serum phosphorus concentration was also higherwith higher net acid excretion and lower serum bicarbonate concentration (each P=0.001). Only higher net acid excretion associated with higher 24-hour urine calcium excretion (P<0.001). Neither net acid excretion nor PRAL was associated with FGF-23 or PTH concentrations. PTH, but notFGF-23, concentration (P=0.2) was 26% (95% CI, 13%-40%) higher in participants with a serumbicarbonate concentration<22 versus≥22 mEq/L (P<0.001). Primary results were similar if stratified by estimated glomerular filtration rate categories or adjusted for iothalamate glomerular filtration rate (n=359), total energy intake, dietary phosphorus, or urine urea nitrogen excretion, when available. Possible residual confounding by kidney function or nutrition; urine phosphorus excretion was included in calculation of the titratable acid component of net acid excretion. In CKD, higher acid load and acidosis associate independently with increased circulating phosphorus concentration and augmented phosphaturia, but not consistently with FGF-23 or PTH concentrations. This may be an adaptation that increases titratable acid excretion and thus helps maintain acid-base homeostasis in CKD. Understanding whether administration of base can lower phosphorus concentrations requires testing in interventional trials.

Relationship between Hepatitis B Viral Deoxyribonucleic Acid Load and Hepatocellular Carcinoma.

Introduction:Hepatitis B virus (HBV) infection is an established cause of hepatocellular carcinoma (HCC) and is associated with poor prognosis. High HBV deoxyribonucleic acid (DNA) load has been identified in HCC and hepatitis B surface antigen-positive patients.Materials and methods:This study was done in the Department of Hepatology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh, from January 2006 to December 2007. Thirty patients with HBV infection-related HCC were enrolled. Another 30 patients with HBV-related liver diseases without HCC were analyzed as controls.Results:The HCC patients had a high viral load (>105 copies/mL), while all of the controls had low (<105 copies/mL) viral load.Conclusion:It seems that patients with HCC bear high HBV DNA loads in Bangladesh, but the causes underlying this remain to be resolved.How to cite this article: Hussain MM, Al Mahtab M, Islam S, Ahmed N, Rahman S, Khan M. Relationship between Hepatitis B Viral Deoxyribonucleic Acid Load and Hepatocellular Carcinoma. Euroasian J Hepato-Gastroenterol 2017;7(1):111-112.

Physiological responses of insects to microbial fermentation products: Insights from the interactions between Drosophila and acetic acid

Acetic acid is a fermentation product of many microorganisms, including some that inhabit the food and guts of Drosophila. Here, we investigated the effect of dietary acetic acid on oviposition and larval performance of Drosophila. At all concentrations tested (0.34–3.4%), acetic acid promoted egg deposition by mated females in no-choice assays; and females preferred to oviposit on diet with acetic acid relative to acetic acid-free diet. However, acetic acid depressed larval performance, particularly extending the development time of both larvae colonized with the bacterium Acetobacter pomorum and axenic (microbe-free) larvae. The larvae may incur an energetic cost associated with dissipating the high acid load on acetic acid-supplemented diets. This effect was compounded by suppressed population growth of A. pomorum on the 3.4% acetic acid diet, such that the gnotobiotic Drosophila on this diet displayed traits characteristic of axenic Drosophila, specifically reduced developmental rate and elevated lipid content. It is concluded that acetic acid is deleterious to larval Drosophila, and hypothesized that acetic acid may function as a reliable cue for females to oviposit in substrates bearing microbial communities that promote larval nutrition.

Long-term intake of a high-protein diet increases liver triacylglycerol deposition pathways and hepatic signs of injury in rats

Intake of high-protein (HP) diets has increased over the last years, mainly due to their popularity for body weight control. Liver is the main organ handling ingested macronutrients and it is associated with the beginning of different pathologies. We aimed to deepen our knowledge on molecular pathways affected by long-term intake of an HP diet. We performed a transcriptome analysis on liver of rats chronically fed with a casein-rich HP diet and analyzed molecular parameters related to liver injury. Chronic increase in the dietary protein/carbohydrate ratio up-regulated processes related with amino acid uptake/metabolism and lipid synthesis, promoting a molecular environment indicative of hepatic triacylglycerol (TG) deposition. Moreover, changes in expression of genes involved in acid–base maintenance and oxidative stress indicate alterations in the pH balance due to the high acid load of the diet, which has been linked to liver/health damage. Up-regulation of immune-related genes was also observed. In concordance with changes at gene expression level, we observed increased liver TG content and increased serum markers of hepatic injury/inflammation (aspartate transaminase, C-reactive protein and TNF-alpha). Moreover, the HP diet strongly increased hepatic mRNA and protein levels of HSP90, a marker of liver injury. Thus, we show for the first time that long-term consumption of an HP diet, resulting in a high acid load, results in a hepatic transcriptome signature reflecting increased TG deposition and increased signs of health risk (increased inflammation, alterations in the acid–base equilibrium and oxidative stress). Persistence of this altered metabolic status could have unhealthy consequences.

Proton exchange nanohybrid membranes with high phosphotungstic acid loading within metal-organic frameworks for PEMFC applications

A novel approach to in-situ synthesize and encapsulate phosphotungstic acid into the cavity of MIL-101(Cr) using Na2WO4·2H2O and Na2HPO4 as precursors is presented to increase the acid loading content (31.4wt.%). The phosphotungstic acid-encapsulating MIL-101(Cr) (HPW@MIL101) is introduced in sulfonated poly(ether ether ketone) (SPEEK) to prepare SPEEK/HPW@MIL101 nanohybrid membranes for PEMFC applications. Due to the introduction of HPW@MIL101, proton-conducting nanochannels are constructed both in the cavity of MIL101 and at the interface between HPW@MIL101 and SPEEK. Meanwhile, due to the hygroscopicity of phosphotungstic acid, the membrane dehydration at elevated temperatures is alleviated. The proton conductivity at low relative humidity is remarkably enhanced. The nanohybrid membrane with 9wt.% HPW@MIL101 exhibits proton conductivity of 272mScm−1 at 65°C, 100% RH and 6.51mScm−1 at 60°C, 40% RH, which are 45.5% and 7.25 times higher than those of pristine SPEEK membrane (187mScm−1 and 0.898mScm−1), respectively. The single H2/O2 fuel cell with SPEEK/HPW@MIL-9 membrane acquires the power density of 383mWcm−2 at 100% RH, which is 27.2% higher than that of pristine SPEEK membrane. The peak power density of SPEEK/HPW@MIL-9 membrane at 55% RH is 2.97 times higher than that of pristine SPEEK membrane (79mW/cm2).

Influence of Dietary Acid Load on Exercise Performance.

Diet composition can affect systemic pH and acid-base regulation, which may in turn influence exercise performance. An acidic environment in the muscle impairs performance and contributes to fatigue; therefore, current trends in sports nutrition place importance on maximizing the alkalinity of the body with ergogenic aids and dietary strategies. This review examines the evidence on the effects of dietary manipulations on acid load and exercise performance. Ten studies that investigated the effect of high versus low dietary acid loads on athletic performance generally identified that low dietary acid loads increased plasma pH, but did not consistently improve exercise performance at maximal or submaximal exercise intensities. In addition, the few studies conducted have several limitations including lack of female subjects and use of exercise tests exclusive to cycling or treadmill running. Although the research does not strongly support a performance benefit from low dietary acid loads, a more alkaline dietary pattern may be beneficial for overall health, as dietary induced acidosis has been associated with greater risk of cardiovascular disease and bone disease. The review includes dietary recommendations for athletes to reduce dietary acid load while still meeting sports nutrition recommendations.

Fe/MMT as an Effective Catalyst for Furan Production from Eucalyptus Enzymatic Hydrolysate in Biphasic Systems

Heterogeneous catalyst, Fe/MMT, was prepared by ion-exchanged and used for conversion the eucalyptus enzymatic hydrolysate into furan products. The result shown prepared Fe/MMT catalyst, having large specific surface area and high acid loading, containing both Lewis and Bronsted acid sites, displayed high activity and good stability during the dehydration reaction. The highest 5-HMF and furfural yields obtained from enzymatic hydrolysate are up to 70.21 and 78.84 %, respectively, a slight higher than those from pure sugar solution. Moreover, a reaction pathway for conversion of C6 and C5 sugar that in the hydrolysate into furan products in the present of Fe/MMT catalyst were also proposed in this study.

Higher diet-dependent renal acid load associates with higher glucocorticoid secretion and potentially bioactive free glucocorticoids in healthy children

Metabolic acidosis induces elevated glucocorticoid (GC) levels. However, the influence of less strong daily acid loads on GCs is largely unexplored. To investigate this, we studied whether higher acid loads in children, fully within the normal range of habitual diets, associate with endogenous GCs. In a specific quasi-experimental design, we examined 200 6- to 10-year-old healthy participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study equally divided to either high or low 24-hour renal net acid excretion. Major urinary GC metabolites were analyzed by gas chromatography-mass spectrometry to assess daily adrenal GC secretion and metabolites of tissue cortisol catabolism (6β-hydroxycortisol and 20α-dihydrocortisol). Liquid chromatography-mass spectrometry was used toquantify urinary free cortisol and cortisone. After confounder adjustment, significant positive associations were unmasked for urinary potential renal acid load and netacid excretion with adrenal GC secretion, free cortisone, free cortisone plus cortisol, 6β-hydroxycortisol, and 20α-dihydrocortisol. An inverse association emerged for anenzymatic marker (5β-reductase) of irreversible GC inactivation. Our data suggest that existing moderate elevations in diet-dependent acid loads suffice to raise GCs and affect cortisol metabolism. Thus, potential detrimental effects of high acid loading appear to be mediated, in part, by increased GC activity via increased GC secretion and/or reduced GC inactivation. Higher cortisone levels, directly available for intracrine activation to cortisol may play a special role.

Potassium Citrate Decreases Bone Resorption in Postmenopausal Women with Osteopenia: A Randomized, Double-Blind Clinical Trial

Diets rich in animal protein, such as the typical American diet, are thought to create a high acid load. An association between acid load and bone loss has led to the idea that providing positive alkaline salt therapy could have beneficial effects on bone metabolism. The objective of this study was to investigate the effects of potassium citrate (K-citrate), 40 mEq daily, over 1 year on bone resorption and formation. A randomized, double-blind, placebo-controlled trial of 83 women with postmenopausal osteopenia. Levels of bone turnover markers, specifically urinary N-telopeptide of collagen type 1 (u-NTX), amino-terminal propeptide of type 1 procollagen (P1NP), bone-specific alkaline phosphatase (BSAP), and osteocalcin (OC) were compared. Changes in bone mineral density (BMD) were also examined. K-citrate decreased both u-NTX (P = .005) and serum P1NP (P<.001) starting at month 1 and continuing through month 12. No significant change was seen in BSAP or OC. No significant change was seen in lumbar or hip BMD between the 2 groups. In women with postmenopausal osteopenia, treatment with K-citrate for 1 year resulted in a significant decrease in markers of turnover. The effect on markers of bone formation was not consistent. K-citrate may serve as a potential treatment for bone loss that is well tolerated and without any significant known long-term consequences.

Assessing relationships between red spruce radial growth and pollution critical load exceedance values

Acidic sulfur (S) and nitrogen (N) deposition depletes cations such as calcium (Ca) from forest soils and has been linked to increases in foliar winter injury that led to the decline of red spruce (Picea rubens Sarg.) in the northeastern United States. We used results from a 30m resolution steady-state S and N critical load exceedance model for New England to better understand the spatial connections between Ca depletion and red spruce productivity. Atmospheric deposition and other inputs were estimated for a 5-year period (1984–1988) in order to smooth year-to-year variations in climate and patterns of atmospheric transport. Deposition levels prior to the reductions that followed the 1990 Amendments to the Clean Air Act were used because tree health and productivity declines were expected to be most responsive to high acid loading. We examined how radial growth (basal area increment) of 441 dominant and co-dominant red spruce trees from 37 sites across Vermont and New Hampshire was related to modeled estimates of S and N critical load exceedance. We assessed growth using statistical models with exceedance as a source of variation, but which also included “year” and “elevation class” (to help account for climatic variability) and interactions among factors. As expected, yearly climate-related sources of variation accounted for most of the differences in growth. However, exceedance was significantly and negatively associated with mean growth for the study period (1951–2010) overall, and particularly for the 1980s and 2000s – periods of numerous and/or severe foliar winter injury events. Because high winter injury reflects the convergence of predisposing (cation depletion) and inciting (weather) factors, exceedance alone appears insufficient to define associated patterns of growth reduction. Significant interactions indicated that exceedance had little influence on growth at low elevations (where intrinsic conditions for growth were generally good) or high elevations (where growth was uniformly poor), whereas exceedance was significantly associated with reduced growth at mid elevations over long periods of time. Exceedance was also linked to reduced growth rebounds following a region-wide foliar winter injury event in 2003. Overall, our analyses suggest that modeled S and N critical load exceedance can help account for red spruce growth and rebound from injury in the field. Interestingly, recent growth for red spruce is above average for the 20th to 21st century dendrochronological record – indicating that the factors shaping growth may be changing. The influence of reduced pollution inputs on this recent growth surge is under investigation.

The role of dietary acid load and mild metabolic acidosis in insulin resistance in humans.

Type 2 diabetes is increasingly being recognised as a global health crisis (World Health Organisation). Insulin resistance is closely associated with obesity and precedes the development of type 2 diabetes. However, there is now increasing evidence to suggest that diet itself may independently be associated with type 2 diabetes risk. A diet with a high acid load (or high potential renal net acid load, PRAL) can result in a decrease in pH towards the lower end of the normal physiological range, which may in turn lead to the development of insulin resistance. Conversely, reducing dietary acid load (the so called 'alkaline diet') may be protective and prevent the onset of type 2 diabetes. Here, we explore the influence of dietary acid load on the development of mild metabolic acidosis and induction of insulin resistance. Whilst large prospective cohort studies link high dietary acid load or low serum bicarbonate with the development of type 2 diabetes, the effect of a diet with a low acid (or high alkaline) load remains unclear. Further interventional studies are required to investigate the influence of dietary composition on the body's acid/base balance, insulin resistance and incidence of type 2 diabetes.

Pharmaceutical electrochemistry: The electrochemical detection of aspirin utilising screen printed graphene electrodes as sensors platforms

A sensitive electrochemical sensor was designed for acetyl salicylic acid detection using graphene modified Screen Printed Electrodes. The electrochemical response of the sensor with graphene was improved compared to Screen Printed Electrodes without graphene and displayed an excellent analytical performance for the detection of acetyl salicylic acid. The high acetyl salicylic acid loading capacity on the electrode surface and the outstanding electric conductivity of graphene were also discussed in this manuscript. When a range of different concentrations of acetyl salicylic acid from 0.1 to 100 μM into a pH 4 buffer solution (N defined as the sample size N = 9) were plotted against the oxidation peak a linear response was observed. The detection limit was found to be 0.09 μM based on (3-σ/slope). Screen Printed Graphene electrodes sensors methodology is shown to be useful for quantifying low levels of acetyl salicylic acid in a buffer solution as well as in biological matrixes such as human oral fluid. A linear response was obtained over a range of concentrations from 10 to 150 μM into a human oral fluid solution (N = 10) giving a detection limit of 8.7 μM.

Metal-organic frameworks with high tungstophosphoric acid loading as heterogeneous acid catalysts

High loadings of 12-tungstophosphoric acid (H3PW12O40) were incorporated within highly porous metal-organic framework MIL-101. The samples have been characterized using different techniques such as XRD, TEM, FT-IR, TGA, N2 adsorption and Raman spectroscopy. XRD and TEM did not show any aggregation of the H3PW12O40 nanocrystals on the surface of MIL-101 crystals up to 70wt%. Similarly, N2 sorption–desorption measurements reveal that samples with H3PW12O40 loading up to 70wt% retain their mesoporosity. The incorporation of H3PW12O40 crystals gradually increases both the surface acidity and the acid strength of the H3PW12O40/MIL-101 catalysts up to 70wt% loading. The catalytic performances of the H3PW12O40/MIL-101 solid catalysts were tested in three acid-catalyzed organic transformations, namely, the Pechmann, Esterification and Friedel–Crafts acylation reactions. In the three reactions, the catalytic activity attains the maximum value at 70wt% of H3PW12O40 loading, thus demonstrating direct correlation with dispersion, mesoporosity and acid strength. The unique attributes of MIL-101 and a well-dispersed level of H3PW12O40 prohibit the conglomeration and deactivation of H3PW12O40, which leads to the enhancement of the catalytic properties. The H3PW12O40 catalysts supported on MIL-101 are potentially promising heterogeneous catalysts for acid-catalyzed organic transformations in environmental friendly processes, to supersede the use of conventional homogeneous H3PW12O40 catalysts.

Is Medical Nutrition Therapy Appropriate for Kidney Stones?

Is Medical Nutrition Therapy Appropriate for Kidney Stones?

Enhanced Proton Conductivity of Nafion Hybrid Membrane under Different Humidities by Incorporating Metal–Organic Frameworks With High Phytic Acid Loading

In this study, phytic acid (myo-inositol hexaphosphonic acid) was first immobilized by MIL101 via vacuum-assisted impregnation method. The obtained phytic@MIL101 was then utilized as a novel filler to incorporate into Nafion to fabricate hybrid proton exchange membrane for application in PEMFC under different relative humidities (RHs), especially under low RHs. High loading and uniform dispersion of phytic acid in MIL 101(Cr) were achieved as demonstrated by ICP, FT-IR, XPS, and EDS-mapping. The phytic@MIL101 was dispersed homogeneously in the Nafion matrix when the filler content was less than 12%. Hybrid membranes were evaluated by proton conductivity, mechanical property, thermal stability, and so forth. Remarkably, the Nafion/phytic@MIL hybrid membranes showed high proton conductivity at different RHs, especially under low RHs, which was up to 0.0608 S cm(-1) and 7.63 × 10(-4) S cm(-1) at 57.4% RH and 10.5% RH (2.8 and 11.0 times higher than that of pristine membrane), respectively. Moreover, the mechanical property of Nafion/phtic@MIL hybrid membranes was substantially enhanced and the thermal stability of membranes was well preserved.