Removal Of Ca2 Research Articles

Sarcoplasmic Reticulum Ca 2+ Handling in Gastrocnemius Muscles from 10‐week‐old C57 and D2‐ mdx Mice

Background Duchenne Muscular Dystrophy (DMD) is an X-linked muscle wasting disease caused by an absence of dystrophin. Secondary mechanisms including elevated myoplasmic Ca2+ as a result of dysfunctional sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) pumps and leaky ryanodine receptors (RyR) can perpetuate disease pathology. Although the widely used preclinical C57BL/10 (C57) mdx mouse model displays moderate muscle damage and weakness, this model falls short in its ability to recapitulate the more severe human phenotype. Conversely, the DBA/2J (D2) mdx mouse model displays severe and early-onset muscle weakness, damage and histopathology; and therefore, more closely mimics human DMD. To date, there has been no characterization of muscle Ca2+ handling in the D2-mdx mouse. Thus, we examined sarcoplasmic reticulum (SR) Ca2+ handling in both D2-mdx and C57-mdx mice. Methods Eight-week-old male C57-WT, C57-mdx, D2-WT and D2-mdx mice were purchased from Jackson Laboratories. All mice underwent a hangwire test and were temporarily housed (48 hr) in a Promethion Metabolic Cage System to measure energy expenditure and cage activity. At 10 weeks of age, mice were euthanized, and gastrocnemius muscles were collected to measure Ca2+ uptake and leak via an Indo-1 fluorimetric assay. Serum creatine kinase (CK) activity was measured using a commercially available kit. Results Consistent with previous literature, serum CK was elevated in both C57-mdx and D2-mdx mice compared with WT, but to a greater extent in the former (8.9-fold vs 3.3 fold, p = 0.04). While both C57-mdx and D2-mdx mice had lowered hangwire time, these impairments were more severe in the D2-mdx mouse (-30% in C57-mdx vs -50% in D2-mdx, p = 0.09). Similarly, while both C57-mdx (-15%) and D2-mdx (-33%) mice had lowered total cage activity, the D2-mdx mice were most affected (p = 0.03). Interestingly, metabolic cage analyses further revealed that D2-mdx (1.3-fold increase) but not C57-mdx mice, had significantly elevated daily energy expenditure compared to their respective WT groups. When examining SR Ca2+ uptake, we found that the D2-mdx mice had significantly elevated starting Ca2+ levels compared with D2-WT mice (5500 vs 2300 nM). When activated by ATP, there was significantly less removal of Ca2+ in the D2-mdx muscles compared with WT (2.6-fold greater area-under-the-curve). However, none of these effects were observed in the C57-mdx mice. Furthermore, when SERCA was inhibited with cyclopiazonic acid, the rate of SR Ca2+ leak (-50%) and the amount of SR Ca2+ released back into the cytosol (-48%) were significantly lowered in the D2-mdx but not in the C57-mdx mice. This is likely reflective of impaired SR Ca2+ uptake and filling. Conclusions Unlike the C57-mdx, the D2-mdx mice displayed early onset muscle weakness with lowered cage ambulation and hangwire time when compared with their respective WT groups. These findings were associated with impaired SR Ca2+ handling in the D2-mdx mice but not the C57-mdx mice. Together, the extensive muscle damage and impaired SR Ca2+ handling in the D2-mdx mice likely enhances their daily energy expenditure.

Patterns of geochemical variability across weakly developed paleosol profiles and their role as regional stratigraphic markers (Upper Pleistocene, Po Plain)

Weakly developed paleosols from two distinct interfluve surfaces of Late Pleistocene age provide excellent keys to high-resolution stratigraphic correlation and may serve to trace large-scale genetic packages (systems tract equivalents) across the continental portion of the Po Basin. Twenty-four paleosol profiles from 17 sediment cores were identified and characterized for bulk-geochemical analysis. X-ray fluorescence data were used to trace the degree of weathering. Paleosols, 0.5–1.5 m thick, are pedogenically altered floodplain deposits, developed over time spans of a few thousand of years and mostly partitioned into A-Bk horizons. The most notable paleosol features are dark, organic-matter-rich and carbonate-free mineral surface horizons (A) that overlie bright calcic horizons (Bk) typified by the accumulation of secondary carbonates in the form of pedogenic nodules.Paleosol profiles exhibit a homogeneous geochemical signature that fingerprints a moderate degree of weathering, with little strike- and dip-oriented variability across the different study localities. Plots of Al-normalized calcification and base loss indices against depth reveal systematic increasing values from intensely altered A horizons to underlying Bk horizons. These trends reflect consistent patterns of Ca translocation from surface horizons deeper into the profile, with significant to almost complete Ca removal from A horizons through leaching and accumulation in Bk horizons. Selected trace element ratios (Ba/Sr, Rb/Sr), redox-sensitive trace elements and Zr contents display opposite, up-profile increasing trends that reflect Sr loss in A horizons, with selective Zr concentration in residual minerals.Vertical trends in element ratios are laterally extensive and consistent on a regional basis and represent key pedochemical/stratigraphic markers that can be traced over great distances (tens of kms) throughout the inland portion of the basin. Through quantitative assessment of the degree of weathering, geochemical profiling provides high potential for robust subsurface paleosol correlation that might not be captured by visual core descriptions alone.

Removal of calcium ions from aqueous solution by bovine serum albumin (BSA)-modified nanofiber membrane: Dynamic adsorption performance and breakthrough analysis

The presence of calcium ion (Ca2+) in process streams has always been a challenge because of its impact to the heat transfer efficiency of process equipment. Polyacrylonitrile (PAN) nanofiber membrane was selected as the basic matrix in this study owing to its strong mechanical strength and chemical stability. Cation-exchange nanofiber membranes with different properties, namely weak ion exchanger (P−COOH), strong ion exchanger (P-SO3H) and amphoteric ion exchanger (P−COOH-BSA; coupled with bovine serum albumin) were synthesized via hydrolysis and coupling reactions. The physicochemical characteristics of these nanofiber membranes were investigated by Fourier-transform infrared spectroscopy, scanning electron microscope, and thermogravimetric analysis. Dynamic adsorption performance and breakthrough analysis of these nanofiber membranes were evaluated at different Ca2+ influent concentrations, flow rate, and configuration of membrane stacking. The maximal removal efficiency of Ca2+ (∼62 %, corresponding to dynamic binding capacity = ∼122 mg/g) was achieved by P−COOH-BSA at 500 mg/L of Ca2+ influent concentration, 2 mL/min of flow rate, and one-layer membrane configuration. Two commonly used mathematical models (Thomas and bed depth service time) were applied in the data fitting for the prediction of breakthrough curve and the determination of optimum operating parameters. The results indicate that the removal of Ca2+ by these nanofiber membranes was very effective due to the high interface mass transfer. In this work, Thomas model was found to be more suitable in elucidating the experimental result trends observed from the dynamic adsorption system.

Use of carbon dioxide to enhance the brine purification and flocculation performance of PAM flocculants

The “CO2–NaOH” brine purification method and flocculation performance of polyacrylamide (PAM) flocculants in vacuum salt making brine purification process are reported in this paper. The scale-forming trends of the brine were assessed by the Langlier index (LSI), the Ryznar stability index (RSI) and the Larson-Skold index (LR). The thermodynamic calculation results and PAM flocculant coagulation mechanism show that removal of Ca2+ and Mg2+ ions and suspended solids (SS) from brine by the “CO2–NaOH” method and PAM flocculants is feasible. The total concentration of Ca2+ and Mg2+ ions was decreased from 486.1 mg/L to 3.41 mg/L, and SS was decreased from 20 mg/L to 5 mg/L at the optimal experimental condition of CO2 flow velocity of 0.04 m3/h, injection time of 30 min, equilibrium pH of 11.5, and the dosage of the FL2949 and AN945SH PAM flocculants of 1 mg/L. LSI, RSI and LR show that the scale-forming was slowed down by brine purification. PAM flocculants were not retained in the brine as confirmed by the analysis of total organic carbon and chemical oxygen demand, and the X-ray diffraction, Fourier transform infrared, and scanning electron microscopy electron dispersive spectroscopy measurements for the flocs sludge during the brine purification process, results shown that the flocs sludge is calcite CaCO3. PAM flocculants purification was applied in industrial testing and achieved deep brine purification to remove scale-forming ions and SS. Additionally, it was found that the “CO2–NaOH” brine purification method promotes the utilization of CO2.

Utilization of Charred Water Hyacinth (Jalkumvi) as Biosorbent for Removal of Ca(II) Ion from Aqueous Solution

A promising adsorbent, charred water hyacinth (CWH) for the removal of Ca(II) from the aqueous solution was explored by heat treatment of water hyacinth followed by chemical activation with acidified zinc chloride (ZnCl2). The adsorbent was characterized using scanning electron microscopy (SEM) and electron dispersive X-ray (EDX) spectroscopy. Batch adsorption techniques were conducted for Ca(II) adsorption to assess the adsorption isotherm, effect of pH, contact time, initial Ca(II) concentration, adsorbent doses, and adsorption kinetics. The SEM micrograph illustrates the rough and irregular surface morphology and EDX spectra confirm the successful adsorption of Ca(II) on the adsorbent surface. The equilibrium adsorption data better fitted to the Freundlich isotherm model having a maximum adsorption capacity (qmax) of 319.75 mg/g. The highest percentage of adsorption was found at pH 1.5. The adsorption of Ca(II) by CWH decreased at the higher metal concentration and lower adsorbent doses. The adsorption of Ca(II) ions onto CWH followed the pseudo-second-order kinetics model. . Overall, these results suggested that the as-prepared CWH can be used as an eco-friendly, economical and efficient alternative for the removal of Ca(II) from the aqueous solution.

Effect of different washing parameters on the fuel properties and elemental composition of wheat straw in water-washing pre-treatment. Part 2: Effect of washing temperature and solid-to-liquid ratio

The present work is the second part of a study conducted to evaluate the effect of basic parameters on the efficiency of water washing pre-treatment. As per the results of Part-1, large sizes and shorter washing durations are favourable for industrial applications, yet low to moderate fouling and corrosion can be expected from them on combustion. The aim of the present study was to further improve the efficiency of the washing pre-treatment for rather short washing durations (5 and 10 min) and a large feedstock size (3 cm) by optimizing the temperature and solid-to-liquid (S:L) ratio. The washing temperatures considered were 20 °C, 40 °C, 60 °C, and 80 °C, while the S:L ratios considered were 1:15, 1:20, 1:30, 1:40, and 1:50. Fuel composition, heating values, energy loss, and fouling and slagging propensity were evaluated. Increasing the washing temperature resulted in the greater removal of ash (25–37%), K (42–55%), Cl (60–81%), S (32–61%), Mg (52–68%), N (17–25%), P (11–37%), and Ca (14–29%). On increasing the S:L ratio, improvement in the removal of ash (27–35%), Cl (73–84%), S (41–59%), and N (21–40%) was also observed. For practical applications, an S:L ratio of 1:15 was found adequate compare to higher S:L ratios. The washing of 3 cm sized wheat straw for 10 min at 40 °C with a 1:15 S:L is recommended for industrial applications, as it shows the least fouling propensity and energy loss.

Synthesis and optimization selective ion-imprinted polymer for the elimination of Ca II ions using Taguchi design

One of the most important problems associated with calcium measurement is the possibility of underdiagnosed due to a false prediction of hypercalcemia results. Ion imprinting has become one of the fast growing technologies that have gained a lot of attention recently especially in the area of materials science. The present work proposes the synthesis and characterization of ion-imprinted polymer (IIP) in the form of porous film for the removal of Ca (II) from aqueous solution and human blood serum. Ca (II)-IIP films are prepared from mixing of two naturally formed biopolymers cellulose and sodium alginate, CaCl2, ECH, EDTA are used as the source of template ions, cross-linker and extraction agent, respectively. Taguchi method is used to optimize the synthesis and adsorption parameters of the new developed IIP. The optimum IIP films are characterized using FTIR, TGA, FESEM and XRD for determining the performance of the imprinting process achieved. PH dosage, initial concentration, reusability, selectivity, isotherm and kinetic study are investigated for the optimized IIP in Ca (II) aqueous solution. The resulted optimum conditions are pH 5.9, initial concentration (50 mg/l), dosage (300 mg) and 90 min contact time. It was clear from the adsorption data that the Ca (II) sorption by Ca (II)-IIP was fitted with the Langmuir isotherm model. The Langmuir adsorption constants for the adsorption of Ca (II) at room temperature are calculated to be (0.017 L/mg) and the R is 0.9469. The rate of removal of Ca (II) by Ca (II)-IIP is sustained between 98.99 and 86.12% for five periods. Furthermore, findings show that the Ca (II)-IIP is can successfully applied for the removal of free Ca (II) ions in human blood serum.

Produced water softening using high-pH catholyte from brine electrolysis: reducing chemical transportation and environmental footprints

This study evaluates the benefits of using brine electrolysis for generating caustic soda (NaOH) and free chlorine for on-site produced water (PWs11Produced Water) treatment. A two-compartment electrochemical cell was shown to generate NaOH solutions (pH > 12, faradic efficiency 93%) and chlorine (faradic efficiency 32%) from a NaCl brine solution at a current density of 10 mA/cm2. The catholyte was used for softening field-collected PWs. The degree of Mg removal depends mostly on the catholyte/PW mixture pH with pH 11 achieving >90% removal. Ca removal is poor (<10%) due to low bicarbonate alkalinity in the PWs. Soda ash alone at a dose equivalent to the total hardness of the PWs helps CaCO3 precipitation and Ca removal (>90%). The combined treatment of the catholyte and a reduced quantity of soda ash achieves better or comparable Ca removal compared to the full stoichiometric amounts of soda ash alone. Ba and Sr removal patterns closely follow those of Ca, suggesting co-precipitation of these cations as the primary removal mechanism. Organic removal is negligible during chemical softening; however, activated carbon filtration achieves >90% of total organic carbon (TOC) removal in all PWs. A treatment scheme is proposed for field generation of caustic soda and chlorine from PW. The economic analysis demonstrates the significant cost-effectiveness of the approach compared to purchasing the NaOH.

Ca2+ signaling driving pacemaker activity in submucosal interstitial cells of Cajal in the murine colon

Interstitial cells of Cajal (ICC) generate pacemaker activity responsible for phasic contractions in colonic segmentation and peristalsis. ICC along the submucosal border (ICC-SM) contribute to mixing and more complex patterns of colonic motility. We show the complex patterns of Ca2+ signaling in ICC-SM and the relationship between ICC-SM Ca2+ transients and activation of smooth muscle cells (SMCs) using optogenetic tools. ICC-SM displayed rhythmic firing of Ca2+transients ~ 15 cpm and paced adjacent SMCs. The majority of spontaneous activity occurred in regular Ca2+ transients clusters (CTCs) that propagated through the network. CTCs were organized and dependent upon Ca2+ entry through voltage-dependent Ca2+ conductances, L- and T-type Ca2+ channels. Removal of Ca2+ from the external solution abolished CTCs. Ca2+ release mechanisms reduced the duration and amplitude of Ca2+ transients but did not block CTCs. These data reveal how colonic pacemaker ICC-SM exhibit complex Ca2+-firing patterns and drive smooth muscle activity and overall colonic contractions.

Effect of different clinical practices on postoperative pain in permanent mandibular molar teeth with symptomatic apical periodontitis: A randomized controlled clinical trial.

This clinical study aimed to evaluate the effect of different clinical practices with endodontic emergency treatment on postoperative pain in mandibular permanent molar teeth with symptomatic apical periodontitis. In the present study, root canal treatment was applied to 100 patients who met the inclusion criteria. Patients were randomly assigned to 5 groups (control, nonsteroidal anti-inflammatory drug [NSAID], NSAID and antihistaminic drug combination, placebo drug, and intracanal cryotherapy) using a web program. In the first visit, after preparation with the WaveOne Gold file system, calcium hydroxide (Ca(OH)2) medicament was placed on the root canals. However, after the treatment of the patients was completed, six patients patients were excluded from the study because they did not come to the control appointment 7 days later. After the removal of Ca(OH)2 medicament in the second session, the root canals were obturated according to cold lateral condensation technique and final restorations of the teeth were performed. Patients' preoperative and postoperative pain values (4-8-12-24-48 and 72 hours) determined by visual analog scale (VAS) were recorded. The data were analyzed statistically using analysis of variance, Kruskal-Wallis test, Friedman test, Wilcoxon test, and Chi-square test. According to the results of our study; there was no significant difference between the groups in terms of age, gender, preoperative pain, and postoperative analgesic requirement (P > 0.05). In all groups, there were significant differences between the values of different times (P < 0.05). While initial pain values were higher than the hours after treatment (P < 0.05), there was no significant difference between postoperative pain values (P > 0.05). When the groups in terms of pain scales measured at different times compared with each other; in all times there was no significant difference between the groups (P > 0.05). It was observed that all clinical practices significantly reduced preoperative pain.

Removal of Ca(II) and Mg(II) hardness by ion exchange resins and soda ash for seawater pretreatment to reduce scale formation in evaporators multi-stage flash desalination

Removal of Ca(II) and Mg(II) hardness by ion exchange resins and soda ash for seawater pretreatment to reduce scale formation in evaporators multi-stage flash desalination

Modified phoenix tree leaves and their adsorption removal of Ca2+ from wastewater

Modified phoenix tree leaves and their adsorption removal of Ca2+ from wastewater

Calcium balance in agrocenoses of Forest Steppe (on the example of agro-industrial complex of Cherkasy region)

For 63 years in the agro-industrial complex ofCherkasy region there was a radical transformationof the structure of sown areas, when the whole period can be divided into a period of increasing intensity of livestock (1956–1995), a transition period (1996–2005) from intensive livestock to intensive grain production. and 2006–2019 — a period of business management of the structure of sown areas and weak development of the livestock industry. Such changes in management lead to the fact that in agriculture the main means of fertility management is by-products of crop production, the yield of which directly depends on the existing structure of sown areas. Circulation of Ca in agriculture of Cherkasy region directly correlates with changes in the structure of sown areas and the type of applied organic fertilizers. With the introduction of manure on an increasing trend are the conditions for increasing the capacity of the balanceof Ca, but with the saturation of the structure of sown areas with fodder crops and removal of by-products for economic purposes, calcium removal increases to 36–47%, and for by-products total removal decreases to 28–35% for reducing the capacity of the balance of Ca. If we do not take into account the content of Ca in the root system in the balance, the balance indicators deteriorate, both during the application of manure and when it is replaced by by-products. It was found that during the period of increasing the yield of manure for growing livestock, the ratio between the newly formed humus and calcium involved remained in the range of 8.1–9.9 to 1 with increasing components of the ratio, and the increase in areas and volumes of liming in this period should be associated with an excess of fresh organic matter from manure and unilateral withdrawal of calcium from livestock and insufficient return to the agrocenosis, which required an increase in liming areas to consolidate the excess of newly formed humus. When replacing manure with by-products, the ratio between the newly formed humus and calcium remained stable against the background of a decrease in the amount of newly formed humus and circulating calcium (up to 12 to 1 in 2016–2019) while reducing the average humus content and soil area with acid reaction, indicating insufficient amount of calcium per unit of humus formed during the critical transformation of the structure of sown areas and increased mineralization of its excess, which should be compensated by theintroduction of lime. Analysis of the dynamics of the economic balance of Ca shows that livestock and poultry is an aggressive factor against agrocenoses in terms of Ca removal. With developed animal husbandry, it is possible to reach a deficit of Ca balance with a population of about 9.56 million heads, and further increase of the population to 12.2 million heads makes the balance negative. With the transformation of livestock in the direction of poultry there is an increase in the deficit of the economic balance in terms of area of agricultural land, which indicates the need for soil liming.

Calmodulin binds to Drosophila TRP with an unexpected mode

Drosophila TRP is a calcium-permeable cation channel essential for fly visual signal transduction. During phototransduction, Ca2+ mediates both positive and negative feedback regulation on TRP channel activity, possibly via binding to calmodulin (CaM). However, the molecular mechanism underlying Ca2+ modulated CaM/TRP interaction is poorly understood. Here, we discover an unexpected, Ca2+-dependent binding mode between CaM and TRP. The TRP tail contains two CaM binding sites (CBS1 and CBS2) separated by an ∼70-residue linker. CBS1 binds to the CaM N-lobe and CBS2 recognizes the CaM C-lobe. Structural studies reveal the lobe-specific binding of CaM to CBS1&2. Mutations introduced in both CBS1 and CBS2 eliminated CaM binding in full-length TRP, but surprisingly had no effect on the response to light under physiological conditions, suggesting alternative mechanisms governing Ca2+-mediated feedback on the channel activity. Finally, we discover that TRPC4, the closest mammalian paralog of Drosophila TRP, adopts a similar CaM binding mode.

Comparison of Needle, Ultrasonic, and Laser Irrigation for the Removal of Calcium Hydroxide from Mandibular Molar Root Canals

Objective: This study aimed to compare the efficacy of conventional needle irrigation (CI), ultrasonically activated irrigation (UAI), photon-induced photoacoustic streaming (PIPS), and shock wave-enhanced emission photoacoustic streaming (SWEEPS) in removing calcium hydroxide [Ca(OH)2] from root canals of mandibular molars using microcomputed tomography. Background: Various adjunctive irrigation strategies have been recommended to improve the removal of Ca(OH)2. No reports have evaluated the SWEEPS laser-activated method for the removal of Ca(OH)2 from root canals of mandibular molars. Materials and methods: Forty mandibular molars were instrumented and filled with Ca(OH)2. Four irrigation groups (CI, UAI, PIPS, and SWEEPS) were established. The volume of root canals and Ca(OH)2 and the Ca(OH)2 volume reduction percentage (%Rd) were calculated. Data were analyzed by one-way analysis of variance and Kruskal-Wallis analysis of variance. Results: The residual Ca(OH)2 in the apical third was higher than that in the cervical and middle thirds in all groups (p < 0.05). Comparison of the %Rd of Ca(OH)2 in mesial canals revealed that PIPS and SWEEPS removed more Ca(OH)2 than CI and UAI in the cervical third (p < 0.05). The middle third of the mesial canals and the cervical and middle thirds of the distal canals did not show significant differences among groups (p > 0.05). Significant differences in the %Rd of Ca(OH)2 were noted between CI and other groups in the apical third of mesial and distal canals (p < 0.05). No group demonstrated complete removal of Ca(OH)2. Conclusions: UAI and laser-activated irrigation significantly improved Ca(OH)2 removal in the apical third of mesial and distal canals. No agitation technique could completely remove Ca(OH)2.

Elucidating the Neuroprotective Role of Formulated Camel α-Lactalbumin-Oleic Acid Complex by Curating the SIRT1 Pathway in Parkinson's Disease Model.

Parkinson's Disease (PD) is characterized by increased oxidative stress and decreased level of dopamine. At present, the therapeutic interventions of PD are associated with undesirable adverse effects. To overcome these side effects, a new candidate bioinspired molecule is needed for the management of PD. Camel α-lactalbumin (α-LA) is the most abundant protein in camel's milk and has a potential to act as a nutraceutical supplement for neurological functions. Oleic acid, a monounsaturated fatty acid, has been widely associated with a reduced risk of PD. The present study aimed to formulate the camel α-LA and oleic acid (CLOA) complex under specific conditions and to evaluate its efficacy as a neuroprotective in rotenone induced PC12 cell model of PD. Our results demonstrated that removal of Ca++ ions from camel α-LA by EDTA enhances its binding efficiency with oleic acid, and the complex was characterized by UV-CD, ANS fluorescence spectroscopy, and NMR spectroscopy. Moreover, CLOA complex treatment reduced the oxidative stress and increased the cell viability by enhancing the level of dopamine and the expression of SIRT1, FOXO3a, HIF-1α, and HSF-1. We also validated the neuroprotective role of the complex by incubating the cells with CLOA complex prior to rotenone treatment. We inferred from the outcome of the results that the individual entity, i.e., α-LA or OA, is not as effective as the complex. Taken together, our study indicates that CLOA complex might be a potential candidate for the development of future therapeutic drugs for PD.

Calcium hydroxide paste removal strategies and bond strengths of epoxy- and silicate-based sealers.

This study evaluated the syringe/needle (SN), passive ultrasonic irrigation (PUI) and XP-endo Finisher (XP) in the removal of Ca(OH)2 -based paste and the bond strength (BS) values of an epoxy resin (AH Plus) and silicate (MTA)-based sealers to root dentin. Eighty lower premolars were assigned: control group (CT), SN, PUI and XP, and subdivided according to the sealer (n=10) for BS. SN has the lowest removal followed by PUI and XP. AH Plus had higher BS for CT compared with SN in all root thirds. CT and XP presented similar BS in the apical and middle thirds and higher than SN and PUI. For MTA, similar BS was observed in the cervical and apical thirds, and in the middle third, CT, PUI and XP presented similar values and higher than SN. PUI and XP methods presented higher efficiency in the Ca(OH)2 removal, and the residual Ca(OH)2 provides a reduction in BS of the AH Plus.

Short communication: Effect of pH on the heat stability of reconstituted reduced calcium milk protein concentrate dispersions

This study aimed to investigate the heat stability of dispersions from reconstituted reduced-calcium milk protein concentrate (RCMPC) with 80% protein or more. The tested RCMPC powders were produced from skim milk subjected to CO2 treatment before and during the process of ultrafiltration. The CO2 injection was controlled to obtain 0 (control, no CO2 injection), 20, 30, and 40% reduction in calcium levels in the RCMPC powders. The RCMPC powders were reconstituted to 10% (wt/wt) protein in deionized water. These dispersions were tested for heat stability in a rocking oil bath at 140°C at unadjusted, 6.5, 6.7, 6.9, and 7.1 pH. Calcium ion activity (CIA) and ionic strength measurements were carried out using a Ca ion-selective electrode and conductivity meter. Unadjusted pH of the dispersions varied from 6.8 in control to 5.96 in 40% RCMPC dispersions. The CIA of unadjusted dispersions ranged from 1.31 mM in control to 2.83 mM in 40% RCMPC. Heat stability, expressed as heat coagulation time (HCT) of unadjusted dispersions decreased as the level of Ca removal in powders increased (from 13.81 min in control to 0.46 min in 40% RCMPC) and was negatively correlated with the CIA of the dispersions. For control RCMPC dispersions, the minimum and maximum heat stability were observed at dispersion pH of 6.5 and 6.9, respectively, followed by a decrease at pH 7.1 (CIA was the lowest). Dispersions from 40% RCMPC and pH 7.1 had the maximum HCT of 30.94 min among all RCMPC dispersions at all pH values. From this study, it can be concluded that improved heat stability in high protein formulation beverages subjected to UHT processing could be achieved through calcium reduction in milk protein concentrates using CO2 injection.

Self-Assembly of Switchable Protein Nanocages via Allosteric Effect

Protein cages have promising applications in highly efficient gene transportation. Many methods of engineering protein–interface interactions have been developed to build such viral mimics. Missing...

Removal of Ca2+ and Mg2+ from oilfield wastewater using reusable PEG/Fe3O4/GO-NH2 nanoadsorbents and its efficiency for oil recovery

The high salinity of oilfield-produced water caused by the presence of metal ions, such as Ca2+ and Mg2+, has a significantly adverse effect on oil recovery. It is crucial to remove these metal ions efficiently before the oilfield wastewater is reinjected down into the oil wells. To address this issue, we prepared a PEG/Fe3O4/GO-NH2 nanoadsorbent by aminating GO, incorporating magnetic Fe3O4 nanoparticles and coating with PEG (PEG = poly(ethylene glycol); GO-NH2 = aminated graphene oxide). We investigated the removal ratios of the nanoadsorbent for Ca2+ and Mg2+. The respective removal ratios for Ca2+ and Mg2+ reached 69.8 % and 61.1 % at 10 min, indicating that the nanoadsorbent was capable of efficiently removing Ca2+ and Mg2+. We also evaluated the reusability of the nanoadsorbent by recycling and reusing it 5 times. At the fifth recycling run, the nanoadsorbent retained relatively high reuse rates (79.1 % for Ca2+, 69.5 % for Mg2+) and removal ratios (69.5 % for Ca2+, 64.3 % for Mg2+), suggesting that the nanoadsorbent possessed relatively high reusability. Oilfield wastewater treated with the nanoadsorbent was employed for oil recovery in core displacement experiments. The oil recovery efficiency significantly increased by 11.8 % compared with untreated oilfield wastewater. Therefore, the PEG/Fe3O4/GO-NH2 nanoadsorbent exhibits considerable potential for the treatment of oilfield wastewater to enhance oil recovery.