Citrate Concentration Research Articles

Next-Generation Optical Fiber Sensors: Gold Nanoparticle/Eu2O3-RGO Hybrid Coating for Phosphate Ion Detection

The investigation of optical sensors for the identification of particular ions is currently a highly active field of study. In this regard, gold nanoparticles (Au NPs) and rare-earth-doped materials, such as europium oxide (Eu2O3), are frequently employed due to their distinctive optical properties, which make them suitable for sensing applications. A cladding-modified optical fiber sensor coated with Eu2O3 modified reduced graphene oxide/tri-sodium citrate functionalized Au NPs is presented for phosphate ion sensing. The phosphate ion sensing of the optical fiber was studied for different tri-sodium citrate concentrations and different europium concentrations against a fixed concentration of phosphate ion. Upon the introduction of phosphate ions to the optical fiber sensor, a voltage shift is detected in all tested samples. The performance of the optical fiber sensor was evaluated throughout a wide range of phosphate ion concentrations, from 100 nM to 500 nM. The sensor's reaction to rising phosphate ion concentrations follows a polynomial pattern. Furthermore, selectivity experiments demonstrate that the optical fiber sensor displays a more pronounced response to phosphate ions when compared to various other ions, including potassium, ammonium, calcium, copper, manganese, magnesium, nitrate, sulfate, bromine, carbonate, chlorine, and others. The sensor characteristics like repeatability, response time variation, and stability were also studied.

The role of coatings and plasticizers compatibility in stability of advanced gastro-resistant self-emulsifying pellets designed for the delivery of volatile compounds: A combined solid-state NMR and dissolution study

The gastro-resistant behaviour of solid self-emulsifying drug delivery systems (S-SEDDS) represents a significant and innovative advancement in delivering poorly soluble drugs. Due to the complexity of these systems and the liquid nature of SEDDS, thorough investigation is essential. This study explored the stability of self-emulsifying (SE) pellets containing the volatile compound thymol coated with gastro-resistant Eudragit® L 30 D-55 water dispersion. The SE pellet cores, composed of Neusilin® US2 with adsorbed SEDDS (thymol, triacylglycerol, Labrasol®, and propylene glycol), microcrystalline cellulose, and chitosan, were prepared using the extrusion/spheronization method and demonstrated optimal technological properties. The 6-month stability of three coating compositions, differing in thickness and triethyl citrate (TEC) concentration in the Eudragit® L topcoat, or the application of an ethylcellulose (EC, Surelease®) sub-coat, was investigated using the combined in vitro dissolution testing and solid-state nuclear magnetic resonance (ss-NMR) for detailed structural characterization. The dissolution data of samples with Eudragit® L topcoat data showed an acceleration of thymol release in acidic conditions, preventing the SE pellets from achieving gastro-resistance. The ss-NMR analysis revealed an incompatibility between TEC and SEDDS (specifically propylene glycol), identified as a TEC phase transition to a liquid phase independent of TEC concentration. Additionally, ss-NMR analysis revealed that neat thymol negatively affected coating layer stability by promoting the plasticization of Eudragit® L. The inclusion of a 10 % Surelease® sub-coat yielded positive results, maintaining the gastro-resistant properties of SE pellets stored under 25 °C/60 % RH for 6 months. However, ss-NMR analysis confirmed ongoing TEC liquefaction after 3 and 6 months, indicating that the oleic acid and triglycerides in Surelease® as plasticizers contributed to this instability. Therefore, this formulation cannot be deemed stable, and using Surelease® as a sub-layer is only a temporary solution. Overall, while plasticizers are commonly used in pharmaceutical technology, they can introduce significant problems in S-SEDDS development, and their use in sub- or topcoats should be carefully considered or avoided. At the same time, it became evident that in-vitro dissolution testing alone cannot capture the slow processes and interactions occurring within the internal structure of these systems.

Determination of Citrate Content of Commonly Transfused Blood Products

Abstract Background Citrate is a calcium-chelating anion used as an anticoagulant in the collection and manufacturing of blood products for transfusion. Overwhelming of normal hepatic catabolism of infused citrate, such as in liver failure or in massive transfusion, may cause citrate toxicity. Resultant hypocalcemia, impaired coagulation, and metabolic alkalosis results in increased patient mortality and morbidity. The citrate load per blood product unit is rarely known to the transfusionist, precluding precise calcium repletion. Manufacturing data of citrate content is available, but it is unreliable and often contradictory. The aim of this project is to directly measure the citrate concentrations of common blood products including packed red blood cells (pRBCs), plasma, and apheresis platelets. Methods Blood products (or samples thereof) were obtained, centrifuged, and assayed using a benchtop enzymatic citrate assay (Sigma-Aldrich). This technique generates a chromogenic product detectable via spectrophotometry at 570nm via conversion of citrate to a pyruvate intermediate. Blood products were serially diluted to the assay’s concentration measurement range based on estimations from the product manufacturing processes. Validation studies were performed to verify no significant interference from native pyruvate or from hemolysis at the dilutions used. All samples were run with a paired reference standard. Product type, storage duration, volume, and anticoagulant/preservative solution were recorded. Results Preliminary testing was performed on eleven pRBC units, twelve apheresis platelet units, and four whole blood(WB)-derived plasma. Measured citrate content of AS-1 and AS-5 units ranged from 43.56 - 114.5 mg while that of AS-3 units ranged from 327.23 – 816.82 mg, compared to manufacturing estimates of 188 mg and 883 mg, respectively. Measured citrate content of apheresis platelets ranged from 822-1533 mg compared to manufacturing estimates of 805 mg. Measured citrate content of WB-derived plasma also exceeded the manufacturing estimate of 1201 mg. Interference from pyruvate and hemolysis were insignificant at the dilutions used for testing. Validation of pRBC segment sampling is ongoing. Conclusion Varying guidelines exist for the correction of hypocalcemia during ongoing trauma resuscitation; however, guidance is limited regarding repletion by specific blood product. Our investigation affirms significant heterogeneity in pRBC citrate concentrations by collection method and identifies lower citrate concentrations than expected. This may be due to citrate metabolism by RBCs during storage. Platelet and FFP products contain significantly greater citrate masses by comparison, with a high degree of variation observed due to inherent product volume variability. Further sampling and testing are ongoing to establish reliable expected citrate loads for commonly transfused blood products.

Efficient epoxidation of (R)-(+)-limonene to limonene dioxide through peracids generated using whole-cell Rhizopus oryzae lipase

Limonene dioxide (LDO) is essential for manufacturing bio-based polycarbonate and non-isocyanate polyurethanes. Herein, we report a strategy for the chemoenzymatic epoxidation of (R)-(+)-limonene to LDO with high selectivity using Rhizopus oryzae whole cells. The presence of sufficient excess acid in the system is essential, in addition to overcoming the hydrolysis of the intermediate product, 1,2-limonene oxide, to accomplish the double epoxidation of limonene. When using a high concentration of H2O2 and trisodium citrate, the conditions were effectively established, even when Novozym 435 was substituted, which had previously been reported to be ineffective in achieving high-yield double epoxidation of limonene. The transfer of H2O2 and peracids between the cell and solvent slowed production. The total amount of peracids generated remained constant, but their concentrations remained moderate, favoring the double epoxidation of limonene. An LDO yield of 93 % and no intermediate product, limonene oxide, were obtained under optimized conditions within 20 h.

Ratios of calcium to citrate administration in blood transfusion for traumatic hemorrhage: A retrospective cohort study.

Massive transfusion with citrated blood products causes hypocalcemia, which is associated with mortality. Recognition of this problem has led to increased calcium administration; however, the optimal dosing is still unknown. This retrospective, single-center study included level 1 trauma patients in 2019 and 2020 who underwent an operation within 12 h of arrival and received a transfusion. Preoperative and intraoperative administrations were totaled to calculate the ratio of administered calcium to the number of blood transfusions for each patient. The citrate content of each blood component was estimated to calculate a second ratio, the ratio of administered calcium to administered citrate. Receiver Operating Characteristic (ROC) curves were performed on both ratios to determine the optimal cutoff values for predicting severe hypocalcemia (ionized calcium <0.9 mmol/L) and hypercalcemia (>1.35 mmol/L) at the end of the intraoperative period. A total of 506 trauma activations were included, receiving a mean of 17.4 citrated blood products and 16.3 mmol of calcium (equivalent to 2400 mg of calcium chloride). No ratio was statistically significant in differentiating severely hypocalcemic patients from the rest. A calcium to blood ratio of 0.903 mmol of administered calcium per citrated blood product differentiated hypercalcemic patients from the rest. Quantifying received calcium and citrated blood products was insufficient to predict severe hypocalcemia, suggesting other contributions to hypocalcemia. We demonstrated an upper-limit ratio for calcium administration in traumatic hemorrhage; however, further studies are required to determine what calcium dosing regimen results in the best outcomes.

Small molecular weight alginate gel porogen for the 3D bioprinting of microvasculature.

In order to recreate the complexity of human organs, the field of tissue engineering and regenerative medicine has been focusing on methods to build organs from the bottom up by assembling distinct small functional units consisting of a biomaterial and cells. This bottom-up engineering requires bioinks that can be assembled by 3D bioprinting and that permit fast vascularization of the construct to ensure survival of embedded cells. To this end, a small molecular weight alginate (SMWA) gel porogen is presented herein. Alginate is a biocompatible biomaterial, which can be easily converted into small porogen gels with the procedure reported in this article. The SMWA porogen is mixed with photo-crosslinkable hydrogels and leached from the hydrogel post-crosslinking to increase porosity and facilitate vascularization. As a proof of concept, this system is tested with the commonly used biomaterial Gelatin Methacryloyl (GelMA). The SMWA porogen-GelMA blend is proven to be bioprintable. Incubating the blend for 20min in a low concentration phosphate buffered saline and sodium citrate solution significantly reduces the remaining porogen in the hydrogel . The intent to completely leach the porogen from the hydrogel was abandoned, as longer incubation times and higher concentrations of phosphate and citrate were detrimental to endothelial proliferation. Nonetheless, even with remnants of the porogen left in the hydrogel, the created porosity significantly improves viability, growth factor signaling, vasculogenesis, and angiogenesis in 3D bioprinted structures. This article concludes that the usage of the SMWA porogen can improve the assembly of microvasculature in 3D bioprinted structures. This technology can benefit the bottom-up assembly of large scaffolds with high cell density through 3D bioprinting by improving cell viability and allowing faster vascularization.

Nanoengineered pure Fe in a citrate matrix (Fe–CIT) with significant and tunable magnetic properties

This work demonstrates the synthesis and characterization of Fe nanoparticles surrounded by a citrate (CIT) matrix prepared at various temperatures and concentrations of metal, capping agent and reducing agent at standard conditions. We study the effect of reactant ratio and reaction temperature on the magnetization of the produced nanoparticles and their crystal structure. We found that for optimal metal concentrations, magnetic saturation increases with increase in the concentration of capping and reducing agents but decreases as the temperature of the reaction increases. Synthesis conditions were tailored to reveal nucleation of particles with average sizes ranging from 24 to 105 nm and a spherical shape. The ultra-high saturation magnetization of 228 emu g-1obtained for samples prepared at a metal precursor concentration of 27.8 mol l-1was attributed to the formation of small magnetic domains. Energy band gap measurements revealed a band gap energy for the Fe nanoparticles in the CIT matrix which is associated with CIT concentration and/or possible formation of a few thin layers of iron oxide shell and does not have a significant effect on the magnetic properties of the samples. Herein, we demonstrate that the synthesis parameters are crucial for the nucleation of Fe-CIT nanoparticles tailoring their magnetizatic properties as well as their potential for different applications.

Advancements in on-site heavy metal detection: Characterizing and sensitive Hg2+ sensing of silver spheroid nanoparticles obtained by laser ablation synthesis in solution

Heavy metal detection in water bodies is crucial to prevent potential harm to the environment, animals and humans. While powerful techniques such as atomic absorption spectrometry exist, they often require extensive sample preparation and are typically confined to laboratory settings. As a result, alternative detection methods such as optical sensors, are under development to provide a simpler, faster, and on-site detection solution. In the present work spheroidal silver nanoparticles (AgNPs) with a mean size of 14.7 ± 0.6 nm were synthesized by laser ablation in a sodium citrate solution. These nanoparticles exhibit a localized surface plasmon resonance (LSPR), which is profoundly dependent on the size, morphology and composition of the nanoparticles and the refractive index of the surrounding media. The detection capabilities of these nanoparticles were assessed by exposing them to various metal ions, revealing a distinctive sensitivity to Hg2+ ions. Notably, this particular ion had a significant impact on the extinction curve of the AgNPs. The impact of synthesis parameters, including sodium citrate and NaCl concentration, as well as pH, on the efficacy of Hg2+ detection was systematically studied. Characterization techniques such as Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), High-Resolution TEM (HRTEM), and Scanning Transmission Electron Microscopy (STEM) were employed to determine the size, morphology, distribution, crystalline structure, and elemental composition of the AgNPs. The results indicated that AgNPs synthesized through laser ablation in a sodium citrate solution exhibited sensitive detection capabilities for Hg2+ ions, reaching an LOD and LOQ of 0.9355 μM and 2.8350 μM respectively.

Impact of milking interval and time on milk spontaneous lipolysis and composition in dairy cows

Milk lipolysis is defined as the hydrolysis of triglycerides, the major component of milk fat, resulting in the release of short-chain fatty acids (FA) responsible for rancid flavor and partial glycerides that impair functional properties such as foaming and creaming abilities. Milk lipolysis is a complex phenomenon that depends on both animal parameters and breeding factors. Milk spontaneous lipolysis is known to be higher in milk from evening milkings than from morning milkings. This may be related to the longer length of overnight milking intervals or to the nycthemeral cycle. In this experiment, our objective was thus to study the impact of both milking intervals and time of day on milk spontaneous lipolysis in twice-daily-milking systems with one of 3 milking intervals: Short Day - Long Night (SD-LN, 6.30 a.m. and 4.30 p.m.,); Long Day - Short Night (LD-SN, 6:30 a.m. and 8:30 p.m.,); and Balanced Day and Night (BDN, 6:30 a.m. and 6:30 p.m.,). To achieve this goal, 21 multiparous dairy cows in mid-lactation were used in a 3 × 3 Latin square design over 3 periods. The experiment lasted 5 weeks, corresponding to 3 experimental periods of 6 d alternating with 8 d of milking with conventional hours (morning-evening gap of 10 h). We confirmed that milk spontaneous lipolysis was influenced by milking interval, but not the milking time. Indeed, we observed more lipolysis in SD-LN evening milk (+0.20 mEq/100 g fat) and LD-SN morning milk (+0.22 mEq/100 g fat), both of which corresponded to a 10 h interval between successive milkings. High lipolysis milk came from cows that produced less milk with a higher milk fat content. No significant difference between milkings was observed for BDN. Milk protein, total P and citrate contents increased according to the duration of mammary gland storage of milk (from 10 to 14 h). There was no effect of milking intervals on milk fat globule diameter. The milk Na+/K+ ratio, indicating an opening of tight junctions in the mammary gland, increased only in evening milkings with BDN and LD-SN. In conclusion, we found that the effect of milking intervals on lipolysis is stronger than that of the nycthemeral cycle.

Deciphering simplified regional anticoagulation with citrate in intermittent hemodialysis: a clinical and computational study

Regional citrate anticoagulation use in intermittent hemodialysis is limited by the increased risk of metabolic complications due to faster solute exchanges than with continuous renal replacement therapies. Several simplifications have been proposed. The objective of this study was to validate a mathematical model of hemodialysis anticoagulated with citrate that was then used to evaluate different prescription scenarios on anticoagulant effectiveness (free calcium concentration in dialysis filter) and calcium balance. A study was conducted in hemodialyzed patients with a citrate infusion into the arterial line and a 1.25 mmol/L calcium dialysate. Calcium and citrate concentrations were measured upstream and downstream of the citrate infusion site and in the venous line. The values measured in the venous lines were compared with those predicted by the model using Bland and Altman diagrams. The model was then used with 22 patients to make simulations. The model can predict the concentration of free calcium, bound to citrate or albumin, accurately. Irrespective of the prescription scenario a decrease in free calcium below 0.4 mmol/L was obtained only in a fraction of the dialysis filter. A zero or slightly negative calcium balance was observed, and should be taken into account in case of prolonged use.

Urinary Response to Consuming Plant-Based Meat Alternatives in Persons with Normal Kidney Function: The SWAP-MEAT Pilot Trial.

Consuming excess animal meat may exacerbate kidney disorders such as urinary stone disease and chronic kidney disease. Plant-based meat alternatives imitate animal meat, and replace animal with vegetable protein, but it is unclear whether eating plant-meat confers similar health benefits as eating whole vegetables. We hypothesized that eating plant-meat when compared with animal meat decreases dietary acid load but increases dietary phosphorus and nitrogen. SWAP-MEAT was a randomized eight-week, crossover trial (NCT03718988) of participants consuming >2 servings/day of either plant-meat or animal meat for each eight-week phase. We measured urine sulfate, ammonium, pH, phosphorus, urea nitrogen, citrate, and creatinine concentrations, and serum creatinine and bicarbonate concentrations from stored participant samples from each phase. At a single site, we enrolled 36 generally healthy participants (mean±SD age 50.2 ± 13.8 years, 67% women, and 69% White). Eating the plant-meat diet vs. eating the animal meat diet was associated with lower mean concentration of urine sulfate (-6.7 mEq/L; 95% CI -11.0, -2.4), urine ammonium (-4.2 mmol/L; 95% CI -8.2, -0.1), urine phosphorus (-9.0 mg/dL; 95% CI -17.5, -0.5), and urine urea nitrogen (-124.8 mg/dL; 95% CI -226.9, -22.6). Eating plant-meat compared with eating animal meat was associated with higher mean urine pH (+0.3 units; 95% CI 0.2, 0.5) and mean urine citrate/creatinine ratio (+111.65; 95% CI 52.69-170.60). After participants consumed a plant-meat diet compared with when they consumed an animal meat diet, mean serum creatinine concentration was lower (-0.07 mg/dL, 95% CI -0.10, -0.04), whereas mean serum bicarbonate concentration was not different. Eating plant-based meat products, compared with eating animal meat, was associated with lower urinary excretion of sulfate, ammonium, phosphorus, and urea nitrogen and higher urinary excretion of citrate. Our findings provide rationale for examining whether plant-based meat will benefit patients with kidney disease.

Analysis of the effect of citrate on radionuclide retention on portlandite

We analysed how citrate (CIT), a chelating agent potentially present in radioactive waste disposals, affects the mobility of four radionuclides (RN): 63Ni, 233U, 152Eu, 238Pu in portlandite, an important hydrated phase of cement, a commonly used material for waste isolation.Portlandite was synthetized in the laboratory and showed high purity and grain size of few μm. This solid, buffers the pH to 12.5 and shows high adsorption capability for the studied RNs: 152Eu and 238Pu exhibited the highest adsorption (Kd ∼1·105 mL g−1) and 233U the lowest (Kd ∼8·102 mL g−1). CIT adsorption was also experimentally evaluated by batch sorption experiments and electrophoretic (ζ-potential) measurements: a non-lineal sorption behaviour was observed, with Kd values decreasing (from ∼1·103 mL g−1) as CIT concentration increased up to 1·10−2 M, according to portlandite sorption sites saturation.In the presence of CIT, a marginal decrease for 233U adsorption in portlandite was observed, one order of magnitude reduction for 63Ni, while 238Pu and 152Eu adsorption decreased significantly. The calculated sorption reduction factors (SRF) for the four RN in the presence of CIT at a concentration of 5·10−3 M were: 2.4, 9.7, 37 and 50.9 for 233U, 63Ni, 238Pu, and 152Eu, respectively.According to the available thermodynamic databases, low complexation between CIT and RN is predicted at pH = 12.5, thus the RN adsorption decrease in the presence of CIT must be attributed to the organic adsorption on portlandite. However, current thermodynamic are still incomplete for this ligand and this pH range and this limits a precise interpretation of the experimental data.

Role of sodium citrate in electrochemical behavior of reinforcing steel exposed to carbonated alkali-activated fly ash contaminated with chloride ions

Alkali-activated fly ash (AAFA) is considered as a promising alternative to ordinary Portland cement (OPC). However, the lack of calcium hydroxide in AAFA leads to an increased susceptibility to carbonation, thereby resulting in a decreased alkalinity of pore solutions in AAFA and significantly impacting the stability of steel passive films. To improve the corrosion resistance of steel in carbonated AAFA environments, sodium citrate was used as an environmentally-friendly corrosion inhibitor with three carboxylate groups. In this context, the corresponding electrochemical behavior of steel exposed to carbonated AAFA solutions with different concentrations of citrate was studied. In spite of the detrimental effect on the initial passivation behavior, sodium citrate was found to effectively improve the corrosion resistance to chloride attack for steel owing to a synergistic inhibition effect of adsorption film and precipitates on the steel surface. In addition, the correlation of citrate concentration and inhibition mechanism in carbonated AAFA solutions was revealed.

The art of tartness: the genetics of organic acid content in fresh fruits.

Organic acids are major determinants of fruit flavor and a primary focus of fruit crop breeding. The accumulation of organic acids is determined by their synthesis, degradation, and transport, all of which are manipulated by sophisticated genetic mechanisms. Constant exploration of the genetic basis of organic acid accumulation, especially through linkage analysis, association analysis, and evolutionary analysis, have identified numerous loci in recent decades. In this review, the genetic loci and genes responsible for malate and citrate contents in fruits are discussed from the genetic perspective. Technologies such as gene transformation and genome editing as well as efficient breeding using marker-assisted selection (MAS) and genomic selection (GS) are expected to break the bottleneck of traditional fruit crop breeding and promote fruit quality improvement.

Electrodeposition of ReMo alloys

The electrodeposition of superconducting ReMo alloys is investigated using highly concentrated electrolytes with acetate, citrate, and the two oxometallate anions, MoO42− and ReO4−. The effects of applied deposition current, the concentrations of acetate, citrate, and metal source in the electrolyte on the film composition, faraday efficiency as well as the partial current densities of Re and Mo are systematically studied. A hybrid complex species, such as (MoO42−)(ReO4−)(HCit3−)2 and its partially reduced form, is proposed to form and mediate the co-deposition reaction. The morphology and superconductivity of alloy films are characterized using microscopy and cryogenic four-probe measurements. The electrodeposited ReMo alloy films maintain the same amorphous grain structure and the same enhanced superconducting transition temperature as pure Re films.

Citrate Promotes Nitric Oxide Production during Human Sperm Capacitation.

Sperm capacitation is a complex process essential for the spermatozoon to recognize and fertilize the oocyte. For capacitation to occur, human spermatozoa require low levels of reactive oxygen species (ROS), increased protein tyrosine phosphorylation, and sufficient levels of energy metabolites such as citrate. Human spermatozoa are exposed to high concentrations of citrate from the seminal plasma, yet the role of citrate in sperm capacitation is largely unknown. We report that citrate can support capacitation in human spermatozoa incubated with no other energy metabolites in the capacitation medium. Reduced capacitation levels were observed in spermatozoa incubated with inhibitors of mitochondrial citrate transporter (CIC), cytosolic ATP-citrate lyase (ACLY), malic enzyme (ME), and nitric oxide synthase (NOS). The role of citrate metabolism in ROS production was further elucidated as citrate increased NO● production in capacitated spermatozoa, whereas inhibition of ACLY reduced NO● production. This research characterizes a novel metabolic pathway for citrate to produce NO● in the process of human sperm capacitation.

Comparative transcriptome analyses reveal regulatory network and hub genes of aluminum response in roots of elephant grass (Cenchrus purpureus)

Aluminum (Al) toxicity severely restricts the growth and productivity of elephant grass in acidic soils around the world. However, the molecular mechanisms of Al response have not been investigated in elephant grass. In this study, we conducted phenotype, physiology, and transcriptome analysis of elephant grass roots in response to Al stress. Phenotypic analysis revealed that a low concentration of Al stress improved root growth while higher Al concentrations inhibit root growth. Al stress significantly increased the citrate (CA) content in roots, while the expression levels of genes related to citrate synthesis were substantially changed. The multidrug and toxic compound extrusion (MATE) family were identified as hub genes in the co-expression network of Al response in elephant grass roots. Phylogenetic analysis showed that hub genes CpMATE93 and CpMATE158 belonged to the same clade as other MATE genes reported to be involved in citrate transport. Additionally, overexpression of CpMATE93 conferred Al resistance in yeast cells. These results provide a theoretical basis for further studies of molecular mechanisms in the elephant grass response to Al stress and could help breeders develop elite cultivars with Al tolerance.

Rheology and Printability of a Porcelain Clay Paste for DIW 3D Printing of Ceramics with Complex Geometric Structures.

The modeling of ceramics with complex geometric structures currently depends on the handcrafted mode, with long cycles, high costs, and low efficiency; additive manufacturing (AM) technology can solve this problem well. Herein, the porcelain clay paste was successfully prepared for the direct ink writing (DIW) 3D printing process of ceramics with complex geometric structures, and the effects of sodium citrate (SC) content on the rheological properties and DIW 3D printability of the porcelain clay paste were investigated in detail. The SC has a vital role in the rheological behavior of porcelain clay paste. Adding SC increases the absolute zeta potential and decreases the viscosity of the paste, while a high SC content will lead to a low storage modulus of the paste. The porcelain clay paste with an SC content of 0.05% and a paste solid content of 75% possesses suitable rheological properties and a storage modulus for DIW 3D printing. The as-prepared porcelain clay paste has high DIW 3D printability at a pressure of 0.5 MPa, and a 3D-printed green body with a well-densified structure can be achieved. After being sintered, the 3D-printed ceramic exhibits high densification and mechanical properties. A green body with complex geometric structures is quickly and precisely modeled by the DIW 3D printing process with the resultant porcelain clay paste as the raw material. This work provides a practical approach to rapidly fabricating ceramics with complex geometrical structures.

Enhancing casein micelle dissociation in diluted skim milk systems using combined processing techniques

The present work aims to evaluate the dissociation of casein micelles in diluted skim milk (SM) systems after undergoing solvent- or emulsifying salt-based dissociation coupled with ultra-high-pressure homogenization (UHPH). Specifically, part I evaluated dilute SM solutions combined with varying ethanol concentrations (0%-60%) at varying temperatures (5-65°C) in combination with UHPH (100-300 MPa), and part II evaluated dilute SM solutions combined with varying concentrations (0-100 mM) of either sodium hexametaphosphate (SHMP) or sodium citrate (SC) in combination with UHPH (100-300 MPa). In part I, high concentrations of ethanol (40%-60% vol/vol) at elevated temperatures (45-65°C) achieved extensive dissociation of casein micelles, especially in combination with UHPH at ≥200 MPa, as shown by a reduction in sample absorbance and in casein particle size compared with the control (dilute SM, 65°C) under optimum conditions (dilute SM, 60% ethanol, 65°C, ≥200 MPa). In part II, the level of casein micelle dissociation using emulsifying salts (ES) was dependent on the ES type and concentration. Considerable casein micelle dissociation in dilute SM systems was achieved with SHMP concentrations ≥1 mM and SC concentrations ≥10 mM, resulting in decreased sample absorbance, bimodal casein size distributions, and increased hydrophobicity (∼2-fold increase in intrinsic fluorescence) compared with the control (dilute SM). This dissociation was further enhanced with UHPH (≥200 MPa). These results indicate that both solvent- and ES-based casein dissociation techniques can be optimized when used in combination with UHPH. Together, these processing techniques can be used to extensively dissociate casein micelles with the potential to use these altered systems for value-added applications such as functional ingredients or encapsulation agents.

Metabolic Control During Macrophage Polarization by a Citrate-Functionalized Scaffold for Maintaining Bone Homeostasis.

Metabolites, as markers of phenotype at the molecular level, can regulate the function of DNA, RNA, and proteins through chemical modifications or interactions with large molecules. Citrate is an important metabolite that affects macrophage polarization and osteoporotic bone function. Therefore, a better understanding of the precise effect of citrate on macrophage polarization may provide an effective alternative strategy to reverse osteoporotic bone metabolism. In this study, a citrate functional scaffold to control the metabolic pathway during macrophage polarization based on the metabolic differences between pro-inflammatory and anti-inflammatory phenotypes for maintaining bone homeostasis, is fabricated. Mechanistically, only outside M1 macrophages are accumulated high concentrations of citrate, in contrast, M2 macrophages consume massive citrate. Therefore, citrate-functionalized scaffolds exert more sensitive inhibitory effects on metabolic enzyme activity during M1 macrophage polarization than M2 macrophage polarization. Citrate can block glycolysis-related enzymes by occupying the binding-site and ensure sufficient metabolic flux in the TCA cycle, so as to turn the metabolism of macrophages to oxidative phosphorylation of M2 macrophage, largely maintaining bone homeostasis. These studies indicate that exogenous citrate can realize metabolic control of macrophage polarization for maintaining bone homeostasis in osteoporosis.