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Search Results (247)

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Keywords = magnesium calcium phosphate

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30 pages, 7306 KB  
Article
Comparative Short-Term Electrochemical and Surface Characterization of Biodegradable Mg–Ca–Sr Alloys with Different Strontium Contents
by Gabriela Leață, Dorin Ioan Cocoș, Ramona Feier, Corneliu Munteanu, Fabian Cezar Lupu, Ion Ciucă and Kamel Earar
J. Funct. Biomater. 2026, 17(8), 418; https://doi.org/10.3390/jfb17080418 - 20 Aug 2026
Viewed by 222
Abstract
Biodegradable Mg–Ca–Sr alloys are promising candidates for temporary implant applications, but their degradation behavior is strongly influenced by alloy composition and electrolyte chemistry. This comparative short-term study investigated how increasing the Sr content from 0.5 to 1.5 wt.% influences the electrochemical response and [...] Read more.
Biodegradable Mg–Ca–Sr alloys are promising candidates for temporary implant applications, but their degradation behavior is strongly influenced by alloy composition and electrolyte chemistry. This comparative short-term study investigated how increasing the Sr content from 0.5 to 1.5 wt.% influences the electrochemical response and surface characteristics of cast Mg–0.5Ca–xSr alloys in 0.9% NaCl and calcium- and magnesium-free Dulbecco’s phosphate-buffered saline (DPBS). Potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy, quantitative image analysis, and energy-dispersive X-ray spectroscopy were used. Increasing the Sr content reduced the corrosion-current density from 0.0110 to 0.0039 mA/cm2 in NaCl and from 0.297 to 0.169 mA/cm2 in DPBS, while the corresponding calculated corrosion rates decreased from 2.51 to 0.886 mm/year and from 6.66 to 3.79 mm/year, respectively. Replicated EIS measurements of both alloys showed that Mg–0.5Ca–1.5Sr exhibited higher charge-transfer resistance than Mg–0.5Ca–0.5Sr in both NaCl (253 ± 15 versus 184 ± 14 Ω·cm2) and DPBS (853 ± 48 versus 615 ± 42 Ω·cm2). NaCl-exposed surfaces showed more porous and discontinuous deposits and a greater number of visible pit-like defects, whereas DPBS produced comparatively continuous P-containing deposits. Overall, increasing the Sr content to 1.5 wt.% was associated with lower polarization-derived global corrosion kinetics and a more resistive interfacial response, whereas electrolyte composition strongly influenced both interfacial impedance and surface-deposit morphology. These findings represent comparative short-term electrochemical and surface-characterization data obtained at 23 ± 1 °C and should not be interpreted as measures of long-term physiological degradation or in vivo performance. Full article
(This article belongs to the Special Issue Medical Application of Functional Biomaterials (3rd Edition))
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17 pages, 548 KB  
Article
Clinical Anterior Segment and Ocular Surface Findings Across Renal Replacement Modalities: Associations with CKD-Related Factors, Mineral Metabolism and Activin A
by Ioana-Madalina Bilha, Stefana Catalina Bilha, Nada Akad, Adrian Covic, Simona Hogaș, Mihai Marian Hogaș, Ioana Alina Halip, Calina Anda Sandu-Boz, Camelia Margareta Bogdanici and Irina Draga Caruntu
Life 2026, 16(8), 1294; https://doi.org/10.3390/life16081294 - 6 Aug 2026
Viewed by 282
Abstract
Background: Chronic kidney disease (CKD) is characterized by persistent inflammation, metabolic dysregulation, and mineral and bone disorder (CKD-MBD), all of which may affect ocular tissues. While retinal manifestations of CKD have been increasingly investigated, data regarding clinical anterior segment modifications and their relationship [...] Read more.
Background: Chronic kidney disease (CKD) is characterized by persistent inflammation, metabolic dysregulation, and mineral and bone disorder (CKD-MBD), all of which may affect ocular tissues. While retinal manifestations of CKD have been increasingly investigated, data regarding clinical anterior segment modifications and their relationship with systemic biochemical parameters remain limited. Methods: We performed a cross-sectional study including 130 participants: 53 non-CKD subjects, 29 patients undergoing maintenance hemodialysis (HD), and 48 kidney transplant recipients (KTRs). All participants underwent comprehensive ophthalmic examination, including best-corrected visual acuity (BCVA), intraocular pressure (IOP) measurement using Goldmann applanation tonometry, Schirmer I test, tear break-up time (TBUT) and assessment of cataract and blepharitis prevalence. Serum creatinine estimated glomerular filtration rate (eGFR), calcium, phosphate, parathyroid hormone (PTH), magnesium, 25-hydroxyvitamin D, and Activin A were recorded. Associations between ocular and systemic parameters were evaluated using correlation and regression analyses. Results: TBUT, Schirmer I and IOP did not differ significantly among groups (all p > 0.05). After adjustment for age, sex, BMI and diabetes mellitus (DM), HD patients showed worse visual acuity than the non-CKD reference group, reflected by higher logMAR BCVA values (adjusted B = +0.128, p = 0.024). In KTRs, higher corrected calcium was independently associated with reduced tear film parameters, correlating with both shorter TBUT (B = −0.903, p = 0.037) and lower Schirmer I values (B = −5.947, p = 0.008). Circulating Activin A increased progressively from controls to KTR to HD patients (median 189.5 vs. 273.0 vs. 314.0 pg/mL, p < 0.001) but showed no independent association with any anterior segment parameter; it was instead associated with cumulative glucocorticoid exposure (B = +1.602, p = 0.024). Conclusions: In CKD, clinical anterior segment and ocular surface differences were largely explained by age, sex, and comorbidity rather than renal replacement modality, with visual acuity deficit persisting in HD after adjusting for these covariates. At the individual level, corrected calcium was the parameter most consistently associated with tear film parameters in KTRs, whereas elevated Activin A was not independently associated with ocular involvement and likely reflects systemic disease activity. Full article
(This article belongs to the Section Medical Research)
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15 pages, 847 KB  
Article
Clinical Evaluation of Low-Dose Magnesium Carbonate as a Phosphate Binder in Chronic Hemodialysis Patients
by Valeri Tzekov, Tanya Kostadinova, Elizabet Artinyan, Rumyana Stoyanova, Evelina Valcheva and Nikolay Dimov
Life 2026, 16(7), 1213; https://doi.org/10.3390/life16071213 - 22 Jul 2026
Viewed by 844
Abstract
Background and Objectives: Hyperphosphatemia is a key component of chronic kidney disease-mineral and bone disorder and is associated with higher rates of cardiovascular events and mortality in patients undergoing dialysis. Phosphate binders are essential for phosphorus reduction, and their evaluation relies on several [...] Read more.
Background and Objectives: Hyperphosphatemia is a key component of chronic kidney disease-mineral and bone disorder and is associated with higher rates of cardiovascular events and mortality in patients undergoing dialysis. Phosphate binders are essential for phosphorus reduction, and their evaluation relies on several factors, such as chemical composition, binding capacity, and safety profile. Unfortunately, long-term management is hindered by high pill burden and poor adherence. Magnesium phosphate binders have proven effectiveness in reducing phosphate levels. Nevertheless, despite their efficacy, they are not widely used in clinical settings because of concerns related to their use. This study assessed the efficacy of low-dose magnesium carbonate as a phosphate binder in patients undergoing chronic dialysis, focusing on its biochemical control, tolerability, and cost-effectiveness. Materials and Methods: A prospective observational study was conducted on 54 hemodialysis patients with end-stage renal disease at a single dialysis center. Patients were taking either 250 mg magnesium carbonate or 2400 mg sevelamer carbonate for 3 months. Results: Both groups showed decreased phosphorus levels, with a 14.2% significant reduction in the magnesium carbonate group (p < 0.001) and a 5.1% reduction in the sevelamer carbonate group. At the end of the study, no significant differences were observed between the groups (p = 0.682). In the magnesium carbonate group at month 3, compared to baseline, no significant differences were detected in other laboratory parameters reflecting calcium–phosphorus metabolism (Ca—p = 0.681, PTH—p = 0.126). Simultaneously, good compliance without clinically relevant gastrointestinal side effects was observed, including the absence of clinically significant hypermagnesemia. Conclusions: The phosphorus-lowering potential of low-dose magnesium carbonate is non-inferior to that of low-dose sevelamer carbonate. However, its favorable safety profile, low incidence of adverse effects, and cost-effectiveness make it a promising option in clinical practice, further highlighting the need for better recognition by physicians. Full article
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37 pages, 2421 KB  
Review
Property-Guided Selection of Fly Ash Across Binder Chemistry Windows
by Man Feng, Zhiliang Zhou, Lilin Yang, Xue Bai, Ning Xie, Tong Gao and Menglei Yue
Coatings 2026, 16(7), 847; https://doi.org/10.3390/coatings16070847 - 16 Jul 2026
Cited by 1 | Viewed by 435
Abstract
Fly ash (FA) recycling into cementitious binders offers a promising route to simultaneously reduce the environmental burden of high-impact construction materials, divert industrial waste from disposal pathways, and generate engineering value from an existing aluminosilicate residue. FA has therefore been widely incorporated into [...] Read more.
Fly ash (FA) recycling into cementitious binders offers a promising route to simultaneously reduce the environmental burden of high-impact construction materials, divert industrial waste from disposal pathways, and generate engineering value from an existing aluminosilicate residue. FA has therefore been widely incorporated into ordinary Portland cement (OPC), calcium sulfoaluminate (CSA) cement, magnesium potassium phosphate cement (MKPC), and alkali-activated/geopolymer systems, where it can improve workability, mechanical strength, durability and promote hydration reactions, depending on the binder chemistry. However, these benefits are not always successful: FA addition may also reduce early-age strength, delay setting, limit reactivity, impair fluidity, or produce under-reacted matrices when ash properties are mismatched with the chemistry window of the target binder. Rather than revisiting these systems as isolated application categories, this review develops a property-guided framework for interpreting and selecting FA across major cementitious routes. It first highlights why FA should not be treated as a single material. Key descriptors include glass content, fineness, calcium level, carbon residue, mineralogy, and beneficiation state. The review then compares four representative binder environments to clarify the role of FA shifts from pozzolanic contributor to filler-dominated hydration modifier to functional regulator, and finally to reactive precursor, including the calcium hydroxide (CH)-rich Portland systems, CH-poor CSA systems, phosphate-bonded MKPC systems, and alkali-activated/geopolymer systems. The central conclusion is that the key question is not simply where FA can be used, but which FA is best matched with which binder chemistry and for what performance objective. Full article
(This article belongs to the Special Issue Advances in Pavement Materials and Civil Engineering—2nd Edition)
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14 pages, 408 KB  
Article
Association Between Serum Parathyroid Hormone Levels and Femoral Bone Mineral Density in Patients with Chronic Kidney Disease Stage 3
by Laura Montaño-Azor, Petra Cantón Guerrero, María Ángeles Jiménez Sánchez, María José Jiménez Moral, Raquel María García-Sáez, María Encarnación Rodríguez-Ortiz, Mariano Rodríguez, Victoria Pendón-Ruiz de Mier and Esperanza Romero-Rodríguez
J. Clin. Med. 2026, 15(14), 5519; https://doi.org/10.3390/jcm15145519 - 14 Jul 2026
Viewed by 348
Abstract
Background: Chronic kidney disease (CKD) is associated with early disturbances in mineral metabolism that contribute to bone fragility. Secondary hyperparathyroidism is a key component of chronic kidney disease–mineral and bone disorder (CKD-MBD) and may affect bone even during the early stages of [...] Read more.
Background: Chronic kidney disease (CKD) is associated with early disturbances in mineral metabolism that contribute to bone fragility. Secondary hyperparathyroidism is a key component of chronic kidney disease–mineral and bone disorder (CKD-MBD) and may affect bone even during the early stages of CKD. This study evaluated the association between serum parathyroid hormone (PTH) concentrations and bone mineral density (BMD) in patients with stage 3 CKD. Methods: A multicenter cross-sectional observational study was conducted in 203 patients with stage 3 CKD. Blood and 24 h urine samples were collected to measure creatinine, calcium, phosphate, magnesium, 25-hydroxyvitamin D, fibroblast growth factor 23 (FGF23), and PTH. Bone mineral density was assessed by dual-energy X-ray absorptiometry (DXA). Associations between serum PTH concentrations and BMD were analyzed. Results: Elevated serum PTH concentrations were associated with lower femoral BMD and less favorable femoral T-scores, whereas no significant associations were observed at the lumbar spine. Serum PTH concentrations were inversely correlated with femoral BMD and femoral T-scores. Patients with reduced femoral BMD also showed higher FGF23 concentrations and lower renal function, while serum calcium, phosphate, magnesium, and 25-hydroxyvitamin D concentrations did not differ significantly among the groups. Conclusions: Elevated serum PTH concentrations were associated with reduced femoral BMD in patients with stage 3 CKD, supporting preferential early involvement of cortical bone. Serum PTH may represent an accessible biomarker for the early identification of patients at increased risk of cortical bone loss before conventional biochemical abnormalities become clinically apparent. Full article
(This article belongs to the Section Nephrology & Urology)
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19 pages, 1347 KB  
Article
A Simplified Equilibrium Framework for Investigating Calcium and Magnesium Relationships in Plasma
by Fanel Dorel Scheaua
Physiologia 2026, 6(3), 45; https://doi.org/10.3390/physiologia6030045 - 7 Jul 2026
Viewed by 382
Abstract
Calcium (Ca2+) and magnesium (Mg2+) are essential divalent cations whose homeostasis is essential for cardiovascular, muscular and metabolic function. Absolute or relative imbalances between Ca and Mg can lead to cardiovascular, metabolic and neurological pathologies. Ionized calcium (Ca2+ [...] Read more.
Calcium (Ca2+) and magnesium (Mg2+) are essential divalent cations whose homeostasis is essential for cardiovascular, muscular and metabolic function. Absolute or relative imbalances between Ca and Mg can lead to cardiovascular, metabolic and neurological pathologies. Ionized calcium (Ca2+) is a biologically active fraction of plasma calcium that is tightly regulated by protein binding, phosphate complexation, magnesium modulation and acid–base status. Ionized calcium plays a central role in multiple physiological processes and is strongly influenced by plasma pH, phosphate concentration and magnesium levels. However, the combined effects of these parameters are difficult to evaluate intuitively because of their nonlinear interactions. In this study, a numerical simulation framework was used to explore how simultaneous variations in pH, phosphate and magnesium may influence ionized calcium under typical physiological plasma conditions as a phenomenological framework linking ionic equilibrium with viscosity-dependent flow parameters under well-mixed plasma conditions. The simulations reveal phenomenological changes in which concurrent increases in pH and phosphate or reductions in magnesium produce disproportionately large decreases in ionized calcium. Within the physiological ranges examined, the results also indicate a region of relative stability for ionized calcium corresponding to Ca/Mg ratios close to 3, while this value should be interpreted as an emergent feature of the modeled parameter space rather than a universal physiological constant. These findings illustrate the importance of considering multiple electrolyte interactions simultaneously when evaluating calcium homeostasis and may provide a conceptual framework for further experimental investigation. Full article
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19 pages, 1340 KB  
Review
Importance of Recognizing Renal Tubular Disorders as a Cause of Bone Hypomineralization and Fractures in Adults
by Carlos Perez Gomes, Alinie da Silva Pichone and Maria Lucia Fleiuss de Farias
Diagnostics 2026, 16(12), 1898; https://doi.org/10.3390/diagnostics16121898 - 18 Jun 2026
Viewed by 734
Abstract
Renal tubular disorders are often overlooked causes of acquired or inherited bone hypomineralization and fragility fractures in adults. The proximal tubule reabsorbs glucose, phosphate, low-molecular-weight proteins, amino acids, bicarbonate, and much of the sodium, potassium, chloride, and calcium. The distal nephron—the thick ascending [...] Read more.
Renal tubular disorders are often overlooked causes of acquired or inherited bone hypomineralization and fragility fractures in adults. The proximal tubule reabsorbs glucose, phosphate, low-molecular-weight proteins, amino acids, bicarbonate, and much of the sodium, potassium, chloride, and calcium. The distal nephron—the thick ascending limb of the loop of Henle, the distal convoluted tubule, and the collecting duct—regulates urine concentration and dilution, maintains acid-base balance via urinary proton secretion, and controls electrolytes, including sodium, potassium, magnesium, and calcium. Tubular defects may cause hyperphosphaturia (high urinary phosphate), hypercalciuria (high urinary calcium), or chronic metabolic acidosis (renal tubular acidosis, RTA). These changes weaken bone mineralization, disrupt bone turnover, and raise the risk of muscle weakness and fractures. This review summarizes acquired and genetic tubulopathies linked to hyperphosphaturia, hypercalciuria, and RTA and outlines a practical diagnostic approach for outpatients with bone fragility and suspected renal tubulopathy. Full article
(This article belongs to the Special Issue Clinical Diagnosis and Management of Metabolic Bone Diseases)
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17 pages, 909 KB  
Article
Approach for Hemolymph Collection and Biochemical Profiling of Invasive Callinectes sapidus: Methodology and Physiological Assessment
by Laura Gentile, Maria Giulia Ferrari, Asia Ferretti, Alessio Bonaldo, Francesco Dondi and Antonina De Marco
Animals 2026, 16(12), 1894; https://doi.org/10.3390/ani16121894 - 18 Jun 2026
Viewed by 461
Abstract
The blue crab, Callinectes sapidus, is an invasive species in the Mediterranean Sea, where it has gained particular attention since 2023 due to its negative ecological and economic impacts. This study aimed to define a standardized method for hemolymph collection and biochemical [...] Read more.
The blue crab, Callinectes sapidus, is an invasive species in the Mediterranean Sea, where it has gained particular attention since 2023 due to its negative ecological and economic impacts. This study aimed to define a standardized method for hemolymph collection and biochemical analysis in male blue crabs from the northern Adriatic Sea, providing data on their physiological status. Hemolymph was collected following a standardized protocol. Preliminary validation tests showed good recovery, stability and linearity results for biochemical analytes, showing no significant analytical interference due to hemolymph pigmentation. Then, key biochemical variables, including glucose, calcium, magnesium, triglyceride, urea, uric acid, aspartate transaminase, gamma-glutamyl transferase, phosphate, potassium, sodium, chloride and total protein, were analyzed. The results revealed considerable variability in the biochemical profiles of the sampled individuals, consistent with the natural heterogeneity expected in a field-collected, mixed-molt cohort, while overall indicating a generally consistent euryhalinity, a good physiological status. The study underscores the importance of standardized protocols for hemolymph analysis in blue crab, contributing to the understanding of its physiology and invasive success. Full article
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23 pages, 2378 KB  
Article
Investigations of Phosphorus Removal Using an Eco-Friendly Modified Biochar: Batch and Continuous Stirred Reactor Studies
by Salah Jellali, Ahmed Amine Azzaz, Wissem Hamdi, Maram Al-Balushi, Ahmed Al-Raeesi, Ahlam Al Hanai, Hamed Al-Nadabi, Jamal Al-Sabahi, Malik Al-Wardy and Mejdi Jeguirim
Water 2026, 18(11), 1348; https://doi.org/10.3390/w18111348 - 2 Jun 2026
Viewed by 572
Abstract
In this study, a sustainable calcium-rich biochar was synthesized via co-pyrolysis at 800 °C of marble waste, animal manure, and lignocellulosic biomass. This biochar (MWM–B) was comprehensively characterized and then valorized for phosphorus (P) removal from real effluent and synthetic solutions in both [...] Read more.
In this study, a sustainable calcium-rich biochar was synthesized via co-pyrolysis at 800 °C of marble waste, animal manure, and lignocellulosic biomass. This biochar (MWM–B) was comprehensively characterized and then valorized for phosphorus (P) removal from real effluent and synthetic solutions in both batch and continuous stirred tank reactor (CSTR) modes. Characterization results confirm the formation and deposition of significant amounts of calcium oxides and calcium hydroxides on the biochar surface, which enhance the biochar’s surface chemistry and textural properties. In batch mode, MWM–B efficiently removes P with a removal capacity (108.4 mg g−1) that is 5.3 times higher than that observed in the CSTR system. This efficiency drop is due to the limited contact time between phosphate species and the biochar particles. Interestingly, the presence of calcium and magnesium in the continuously renewed real effluent in the CSTR system increases P removal efficiency by approximately 136% compared with synthetic solutions. A detailed analysis of MWM–B before and after P removal suggests that this process occurs mainly through precipitation as hydroxyapatite, complexation with hydroxyl functional groups, electrostatic interactions, and hydrogen bonding. This work confirms that MWM–B generated at 800 °C is an attractive material for P removal from effluents. Full article
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16 pages, 2084 KB  
Article
Functional Fertilizers Increase Yield and Enhance Aroma Quality by Modulating Volatile Compounds in Japonica Fragrant Rice Under Yunnan Field Conditions
by Jinwen Zhang, Wei Deng, Limei Kui, Jian Tu, Yuran Xu, Junjiao Guan, Anyu Gu, Qin Yu, Hua An and Xiaolin Li
Agronomy 2026, 16(11), 1075; https://doi.org/10.3390/agronomy16111075 - 29 May 2026
Viewed by 297
Abstract
Fertilizer management plays a critical role in regulating both yield and aroma quality in fragrant rice. However, the combined effects of functional fertilizers on these traits across different varieties and ecological conditions remain poorly understood. In this study, field experiments were conducted at [...] Read more.
Fertilizer management plays a critical role in regulating both yield and aroma quality in fragrant rice. However, the combined effects of functional fertilizers on these traits across different varieties and ecological conditions remain poorly understood. In this study, field experiments were conducted at two sites (Fumin and Dali) using two japonica fragrant rice varieties (Yunjing 37 and Liuxiangzi 1) under four fertilization treatments: T1 (conventional fertilization); T2 (compound fertilizer + silicon fertilizer); T3 (compound fertilizer + magnesium ammonium phosphate + amino acid-chelated calcium); and T4 (compound fertilizer + bio-organic fertilizer + zinc + amino acid water-soluble fertilizer). Compared with T1, silicon application (T2) significantly increased grain yield by 8.58–15.08%, primarily through synergistic increases in effective panicles and grains per panicle. Treatments T3 and T4 significantly enhanced grain 2-acetyl-1-pyrroline (2-AP) content by 18.32–32.67% and increased the diversity of volatile compounds. Correlation analysis revealed that 2-AP content was positively correlated with ketones (r = 0.373, p < 0.05) and alcohols (r = 0.363, p < 0.05), and negatively correlated with aldehydes and esters. Multifactor ANOVA showed no significant variety × treatment interaction for yield or 2-AP content (p > 0.05), indicating consistent responses across varieties. These results provide preliminary evidence that silicon fertilizer serves as an effective strategy for yield improvement, while combined application of calcium, magnesium, and amino acids enhances aroma quality by promoting the accumulation of 2-APm ketones, and alcohols. However, because treatments T3 and T4 contained multiple components, the individual contributions of Ca, Mg, or amino acids cannot be isolated. Multi-year trials are required to confirm the stability of these effects, featuring a differentiated fertilization strategy—silicon for yield and medium/trace elements for aroma—applicable across varieties, with site-specific variety selection further optimizing performance. Full article
(This article belongs to the Section Farming Sustainability)
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25 pages, 1267 KB  
Article
Integrated Assessment of Bio-Based Phosphorus Fertilizers as an Alternative to Mineral Fertilizers
by Nieves Nunez-Romero, Barbara J. Cade-Menun, Ana M. García-López, Jose Manuel Quintero and Antonio Delgado
Agronomy 2026, 16(11), 1058; https://doi.org/10.3390/agronomy16111058 - 27 May 2026
Viewed by 718
Abstract
Sustainable phosphorus (P) management in agriculture requires a circular economy approach through the use of so-called bio-based fertilizers (BBFs). The properties of BBFs vary widely depending on raw materials and production processes. However, it is still unknown how these properties, and particularly the [...] Read more.
Sustainable phosphorus (P) management in agriculture requires a circular economy approach through the use of so-called bio-based fertilizers (BBFs). The properties of BBFs vary widely depending on raw materials and production processes. However, it is still unknown how these properties, and particularly the dominant P compounds determine not only the efficiency of BBFs in supplying P to crops, but also their effects on soil functioning and crop quality. This study aimed to evaluate the efficiency of a representative set of BBFs, and relate this efficiency to their composition and dominant P compounds. To this end, 14 BBFs were studied: four from water purification (struvite, vivianite, and sewage sludge with and without composting), four composts (municipal solid waste (MSW), vineyard residues, and two using olive husks), three vermicomposts (two homemade and one commercial), fish meal, digestate, and a commercial organic fertilizer. Phosphorus forms in BBFs were determined using 31P nuclear magnetic resonance spectroscopy (P-NMR). The BBFs were compared to a single superphosphate (SSP) in a pot experiment growing wheat in two different alkaline soils, one rich in iron (Fe) oxides and one rich in carbonates. The effects on critical elements in grain [magnesium, Fe, zinc (Zn), manganese, and copper] and enzyme activities related to soil functioning and P cycling were also assessed. The dominant P compound in the BBFs was orthophosphate (73.8–89.5% of the total P in the NaOH–EDTA extracts). The MSW had the highest polyphosphate content (4.1%), a complex inorganic P compound. The organic P content ranged from 9.2% (fish meal) to 25.5% (Moge). Sewage sludge and composted sludge contributed high levels of phosphonates (4.1 and 5.6% of extracted P). The most abundant organic P compound class was inositol hexakisphosphates (IHPs), and myo-IHP (phytate) was the dominant IHP stereoisomer (1.2–6.4%) followed by D-chiro-IHP and scyllo-IHP. Plant dry matter and grain yield with most BBFs were not significantly different from that of SSP in both soils, likely due to the high concentrations of phosphate in relatively soluble forms in most of the BBFs. Vivianite and sewage sludge resulted in significantly higher grain yield than SSP (43% and 40%, respectively) in the carbonate-rich soil, likely due to progressive phosphate dissolution, which decreased the precipitation rate of insoluble calcium (Ca) phosphates. The highest P recoveries were obtained with horse manure vermicompost (65% and 15% higher than SSP in the Fe oxide-rich and in the carbonate-rich soil, respectively), partially attributed to the decreased precipitation rate of insoluble Ca phosphates with the added organic matter. Some BBFs increased micronutrient concentrations in grains and most decreased the P-to-Zn ratio relative to SSP. Overall, phosphatase and β-glucosidase activities increased with carbon-rich BBFs. Most of the studied BBFs could effectively replace fertilizers from non-renewable sources, in some cases with better crop P recoveries. Furthermore, some BBFs could provide additional benefits to grain quality, in terms of micronutrient supply for humans, and soil functioning. Full article
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20 pages, 24037 KB  
Article
Formation and Performance of a Polymer–Cement Composite Gel in Magnesium Phosphate Cement Grouting Materials Modified by Steel Slag and Latex Powder
by Jingwei Zhang, Aolin Zhang and Jia Li
Gels 2026, 12(6), 455; https://doi.org/10.3390/gels12060455 - 22 May 2026
Viewed by 384
Abstract
Magnesium phosphate cement (MPC) shows great potential for complex underground environments due to its rapid-hardening and early-strength properties. However, its large-scale application is hindered by several drawbacks, including high hydration heat, rapid setting, and insufficient long-term durability. To address these limitations, this study [...] Read more.
Magnesium phosphate cement (MPC) shows great potential for complex underground environments due to its rapid-hardening and early-strength properties. However, its large-scale application is hindered by several drawbacks, including high hydration heat, rapid setting, and insufficient long-term durability. To address these limitations, this study developed a novel MPC grouting material modified with steel slag (SS) and redispersible latex powder (LP). We systematically investigated the workability, mechanical properties, durability, and microstructural evolution of this modified system. Results indicate that incorporating SS and LP decreases both the fluidity and setting time of the grout. An optimal SS dosage accelerates reaction kinetics and raises the peak hydration temperature. Conversely, the LP-induced polymer film suppresses the overall temperature rise, delaying the first exothermic peak and advancing the second. The incorporation of 5% steel slag increased the 28-day compressive strength of the MPC to 54.86 MPa. Building on this, the combined addition of 0.15% latex powder further elevated the strength to 58.82 MPa. Microstructural and pore analyses confirmed that the steel slag enhanced interfacial bonding through physical filling and the formation of calcium phosphate crystals. Meanwhile, the latex powder formed a continuous polymer film, which tightly wrapped and bridged the hydration products and unreacted particles. This synergistic mechanism effectively sealed the capillary pores and reduced the proportion of harmful pores by 15.99% compared to the control group. Consequently, the densified MPC matrix laid a solid microstructural foundation for the material’s excellent durability. It offers reliable, high-performance material for seepage control and strata reinforcement in complex environments. Full article
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27 pages, 33336 KB  
Article
Water Quality Metrics of Fishponds During the Cold Season, with a Focus on the Potential Risk of Metals and Microplastics
by Marinela Mirica Gancea, Cristiana Radulescu, Andreea Laura Banica, Ioana Daniela Dulama, Raluca Maria Stirbescu, Ioan Alin Bucurica, Mioara Costache and Mariana Cristina Arcade
Toxics 2026, 14(5), 403; https://doi.org/10.3390/toxics14050403 - 8 May 2026
Viewed by 1655
Abstract
Aquaculture in ponds supplied by streams or rivers requires careful evaluation of key physicochemical parameters and potential pollution threats, particularly metals and microplastics. To address these challenges, this research aims to monitor daily climatic and physicochemical parameters and quantify potentially toxic metals and [...] Read more.
Aquaculture in ponds supplied by streams or rivers requires careful evaluation of key physicochemical parameters and potential pollution threats, particularly metals and microplastics. To address these challenges, this research aims to monitor daily climatic and physicochemical parameters and quantify potentially toxic metals and microplastics in the water of 19 fishponds in the SCDP Nucet, Romania, over one winter season (i.e., December 2024 to February 2025). During this season, unique hydrochemical conditions arise, such as lower temperatures, reduced light, and decreased activity, which can affect the ecological balance and fish health. Accordingly, a total of 4650 samples were collected and analyzed in terms of physicochemical parameters (i.e., alkalinity, bicarbonate, calcium ions, magnesium ions, Ca2+/Mg2+ ratio, organic matter, nitrates, nitrites, phosphates, ammonium, total hardness, resistivity, dissolved oxygen, conductivity, salinity, turbidity, free and total chlorine), metals, and microplastics. Statistical analysis revealed the influence of winter weather on water quality, highlighting links between air and water temperatures and physicochemical parameters. Furthermore, water analyses revealed notable levels of microplastics, including fibers and fragments of various colors, shapes, and sizes. Polypropylene, polyethene, and nylon were the most prevalent. While appreciable quantities of blue, green, black, and yellow fibers were found in size ranges (0.09–0.3 mm), irregular yellow fragments or translucent particles were found in sizes less than 0.5 mm. Metal (i.e., Cr, Fe, Ni, Co, Cu, Zn, Cd, and Pb) concentrations do not exceed the standard values set by national and European regulations. However, it is worth noting that microplastics can amplify or mitigate metal toxicity. The results emphasize the importance of integrated monitoring of physicochemical parameters and emerging pollutants during the cold season, thereby improving understanding of the chemical processes governing water quality in fishponds, providing scientific support for future environmental risk assessment, and promoting innovative, adaptive technologies. Full article
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27 pages, 18982 KB  
Article
Composite Materials Based on Bioresorbable Polymers and Phosphate Phases for Bone Tissue Regeneration
by Oana Maria Caramidaru, Celina Maria Damian, Gianina Popescu-Pelin, Mihaela Bacalum, Roberta Moisa, Cornelia-Ioana Ilie, Sorin-Ion Jinga and Cristina Busuioc
J. Compos. Sci. 2026, 10(5), 223; https://doi.org/10.3390/jcs10050223 - 23 Apr 2026
Cited by 1 | Viewed by 1208
Abstract
Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth [...] Read more.
Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg2+) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg2P2O7) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article
(This article belongs to the Special Issue Biomedical Composite Applications)
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15 pages, 1016 KB  
Article
Stem Electrical Conductivity of Broccoli (Brassica oleracea L. var. italica Plenk) Under Nitrogen and Phosphorus Fertilizer Deficiency
by Jeong Yeon Kim, Su Kyeong Shin, Ye Eun Lee and Jin Hee Park
Agronomy 2026, 16(8), 778; https://doi.org/10.3390/agronomy16080778 - 9 Apr 2026
Cited by 2 | Viewed by 579
Abstract
Nitrogen (N) and phosphorus (P) are essential nutrients that play critical roles in plant physiological processes and the accumulation of N and P in broccoli head was significantly correlated with yield. Therefore, there is a need for a rapid, non-destructive diagnosis of crop [...] Read more.
Nitrogen (N) and phosphorus (P) are essential nutrients that play critical roles in plant physiological processes and the accumulation of N and P in broccoli head was significantly correlated with yield. Therefore, there is a need for a rapid, non-destructive diagnosis of crop status by detecting deficiencies in essential nutrients. This study evaluated the effects of N and P deficiency on field grown broccoli (Brassica oleracea L. var. italica Plenk) using a plant-induced electrical signal (PIES) sensor, in which needle electrodes are inserted into the stem to measure electrical conductivity reflecting plant water and ion status. Four treatments were established, including the control (N100P100) with sufficient N and P supply, N deficiency (N0P100), P deficiency (N100P0), and combined N–P deficiency (N0P0). For sufficient supply, urea and fused phosphate (FP) were applied at rates of 122 kg N ha−1 and 71 kg P ha−1, respectively. Soil, stem, and leaf nutrient contents, growth parameters, and stress related indicators were analyzed and their relationship with PIES values were evaluated. PIES was highest in control (N100P100) and lowest under N–P deficiency (N0P0). Higher PIES values were observed during the vegetative stage, whereas values declined during the reproductive stage, reflecting changes in physiological activity. Growth parameters such as shoot and root weight and stem diameter were generally superior in the control (N100P100) treatment, while leaf calcium (Ca), magnesium (Mg), and potassium (K) concentrations showed no significant differences among treatments. Total N content in leaves was higher in N fertilized treatments (control and P deficiency). Photosynthesis-related parameters, including soil plant analysis development (SPAD), Fv/Fm, and chlorophyll content, were lowest under N–P deficiency, which was reflected in the PIES. Principal component analysis (PCA) showed that the PIES was closely associated with growth and photosynthetic parameters and clearly distinguished N sufficient treatments (control and P deficiency) from N deficient treatments (N0P100, N0P0). Overall, these findings suggest that PIES monitoring can serve as a sensitive physiological indicator of nutrient stress and may be applied as an early diagnostic tool before visible growth inhibition occurs in broccoli cultivation. Full article
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