RESUMEN
In contaminated water and soil, little is known about the role and mechanism of the biometabolic molecule siderophore desferrioxamine-B (DFO) in the biogeochemical cycle of uranium due to complicated coordination and reaction networks. Here, a joint experimental and quantum chemical investigation is carried out to probe the biomineralization of uranyl (UO22+, referred to as U(VI) hereafter) induced by Shewanella putrefaciens (abbreviated as S. putrefaciens) in the presence of DFO and Fe3+ ion. The results show that the production of mineralized solids {hydrogen-uranium mica [H2(UO2)2(PO4)2·8H2O]} via S. putrefaciens binding with UO22+ is inhibited by DFO, which can both chelate preferentially UO22+ to form a U(VI)-DFO complex in solution and seize it from U(VI)-biominerals upon solvation. However, with Fe3+ ion introduced, the strong specificity of DFO binding with Fe3+ causes re-emergence of biomineralization of UO22+ {bassetite [Fe(UO2)2(PO4)2·8(H2O)]} by S. putrefaciens, owing to competitive complexation between Fe3+ and UO22+ for DFO. As DFO possesses three hydroxamic functional groups, it forms hexadentate coordination with Fe3+ and UO22+ ions via these functional groups. The stability of the Fe3+-DFO complex is much higher than that of U(VI)-DFO, resulting in some DFO-released UO22+ to be remobilized by S. putrefaciens. Our finding not only adds to the understanding of the fate of toxic U(VI)-containing substances in the environment and biogeochemical cycles in the future but also suggests the promising potential of utilizing functionalized DFO ligands for uranium processing.
Asunto(s)
Shewanella putrefaciens , Uranio , Biomineralización , Deferoxamina/metabolismo , Deferoxamina/farmacología , Shewanella putrefaciens/metabolismo , Sideróforos/metabolismo , Sideróforos/farmacología , Uranio/química , Compuestos de Hierro/químicaRESUMEN
Immobilization of uranyl by indigenous microorganisms has been proposed as an economic and clean in-situ approach for removal of uranium, but the potential mechanisms of the process and the stability of precipitated uranium in the presence of widespread Fe(III) (hydr)oxides remain elusive. The potential of iron to serve as a reductant and/or an oxidant of uranium indicates that bioemediation strategies which mainly rely on the reduction of highly soluble U(VI) to poorly soluble U(IV) minerals to retard uranium transport in groundwater may be enhanced or hindered under different environmental conditions. This study purposes to determine the effect of ubiquitous Fe(III) (hydr)oxides (two-line ferrihydrite, hematite and goethite) on the removal of U(VI) by Leifsonia sp. isolated from an acidic tailings pond in China. The removal mechanism was elucidated via SEM-EDS, XPS and Mössbauer. The results show that the removal of U(VI) was retarded by Fe(III) (hydr)oxides when the initial concentration of U(VI) was 10 mg/L, pH was 6, temperature was 25 °C. Particularly, the retardatory effect of hematite on U(VI) removal was blindingly obvious. Also, it is worth noting that the U(VI) in the precipitate slow-released in the Fe(III) (hydrodr) oxide treatment groups, accompanied by an increase in Fe(II) concentration. SEM-EDS results demonstrated that the ferrihydrite converted to goethite may be the reason for U(VI) release in the process of 15 days culture. Mössbauer spectra fitting results further imply that the metastable iron oxides were transformed into stable Fe3O4 state. XPS measurements results showed that uranium product is most likely a mixture of Iron-U(IV) and Iron-U(VI), which indicated that the hexavalent uranium was converted into tetravalent uranium. These observations imply that the stability of the uranium in groundwater may be impacted on the prevailing environmental conditions, especially the solid-phase Fe(III) (hydr)oxide in groundwater or sediment.
Asunto(s)
Compuestos de Hierro , Minerales , Monitoreo de Radiación , Uranio , Compuestos Férricos/química , Uranio/química , Oxidación-Reducción , Hierro , ÓxidosRESUMEN
The ferroptosis pathway is recognized as an essential strategy for tumor treatment. However, killing tumor cells in deep tumor regions with ferroptosis agents is still challenging because of distinct size requirements for intratumoral accumulation and deep tumor penetration. Herein, intelligent nanocapsules with size-switchable capability that responds to acid/hyperthermia stimulation to achieve deep tumor ferroptosis are developed. These nanocapsules are constructed using poly(lactic-co-glycolic) acid and Pluronic F127 as carrier materials, with Au-Fe2 C Janus nanoparticles serving as photothermal and ferroptosis agents, and sorafenib (SRF) as the ferroptosis enhancer. The PFP@Au-Fe2 C-SRF nanocapsules, designed with an appropriate size, exhibit superior intratumoral accumulation compared to free Au-Fe2 C nanoparticles, as evidenced by photoacoustic and magnetic resonance imaging. These nanocapsules can degrade within the acidic tumor microenvironment when subjected to laser irradiation, releasing free Au-Fe2 C nanoparticles. This enables them to penetrate deep into tumor regions and disrupt intracellular redox balance. Under the guidance of imaging, these PFP@Au-Fe2 C-SRF nanocapsules effectively inhibit tumor growth when exposed to laser irradiation, capitalizing on the synergistic photothermal and ferroptosis effects. This study presents an intelligent formulation based on iron carbide for achieving deep tumor ferroptosis through size-switchable cascade delivery, thereby advancing the comprehension of ferroptosis in the context of tumor theranostics.
Asunto(s)
Compuestos Inorgánicos de Carbono , Ferroptosis , Hipertermia Inducida , Compuestos de Hierro , Nanocápsulas , Nanopartículas , Neoplasias , Humanos , Línea Celular Tumoral , Neoplasias/terapia , Sorafenib , Hipertermia/terapia , Hipertermia Inducida/métodos , Microambiente TumoralRESUMEN
Extraction of bioactive compounds from Withania somnifera roots was studied using sodium acetate-glycerol deep eutectic solvent (DES) and two techniques ultrasound-assisted extraction (UAE) and heat-assisted extraction (HAE) under response surface methodology (RSM). For UAE and HAE, total phenolic content (TPC, mg gallic acid equivalents per g dry weight (mg GAE g-1 DW)), total flavonoid content (TFC, mg rutin equivalents g-1 DW (mg RE g-1 DW)), radical scavenging activity (RSA, mg AAE (ascorbic acid equivalents) g-1 DW), and iron chelating activity (ICA, mg EDTAE (ethylenediaminetetraacetate equivalents) g-1 DW%) were 6.51, 6.08, 12.56, and 3.57, respectively, and 3.33, 3.98. 6.57 and 2.48, respectively. For UAE, the optimal conditions were a DES concentration of 50 %, temperature of 60 °C, and time of 20 min, and for HAE, a DES concentration of 60 %, temperature of 60 °C, and time of 75 min. The discovered models were strongly supported by the validation experiments. UAE was more efficient and less time-consuming for extracting phytoconstituents of the W. somnifera than HAE.
Asunto(s)
Calor , Withania , Antioxidantes , Disolventes Eutécticos Profundos , Extractos Vegetales , Flavonoides/química , Flavonoides/metabolismo , Complejos de Coordinación/química , Compuestos de Hierro/químicaRESUMEN
Purpose: Improving the treatment of triple-negative breast cancer (TNBC) is a serious challenge today. The primary objective of this study was to construct MUC1-C shRNA@ Fe3O4 magnetic nanoparticles (MNPs) and investigate their potential therapeutic benefits in alternating magnetic fields (AMF) on TNBC. Methods: Firstly, we verified the high expression of MUC1 in TNBC and synthesized specific MUC1-C shRNA plasmids (MUC1-C shRNA). Then, we prepared and characterized MUC1-C shRNA@Fe3O4 MNPs and confirmed their MUC1-C gene silencing effect and magneto-thermal conversion ability in AMF. Moreover, the inhibitory effects on TNBC in vitro and in vivo were observed as well as biosafety. Finally, the protein levels of BCL-2-associated X protein (Bax), cleaved-caspase3, glutathione peroxidase inhibitor 4 (GPX4), nuclear factor erythroid 2-related factor 2 (NRF2), and ferritin heavy chain 1 (FTH1) in TNBC cells and tissues were examined, and it was speculated that apoptosis and ferroptosis were involved in the synergistic treatment. Results: MUC1-C shRNA@ Fe3O4 MNPs have a size of ~75 nm, with an encapsulation rate of (29.78±0.63) %, showing excellent gene therapy and magnetic hyperthermia functions. Under a constant AMF (3Kw) and a set concentration (200µg mL-1), the nanoparticles could be rapidly warmed up within 20 minutes and stabilized at about 43 °C. It could be uptaken by TNBC cells through endocytosis and significantly inhibit their proliferation and migration, with a growth inhibition rate of 79.22% for TNBC tumors. After treatment, GPX4, NRF2, and FTH1 expression levels in TNBC cells and tumor tissues were suppressed, while Bax and cleaved-caspase3 were increased. As key therapeutic measures, gene therapy, and magnetic hyperthermia have shown a synergistic effect in this treatment strategy, with a combined index (q index) of 1.23. Conclusion: In conclusion, we developed MUC1-C shRNA@Fe3O4 MNPs with magnetic hyperthermia and gene therapy functions, which have shown satisfactory therapeutic effects on TNBC without significant side effects. This study provides a potential option for the precision treatment of TNBC.
Asunto(s)
Nanopartículas de Magnetita , ARN Interferente Pequeño , Neoplasias de la Mama Triple Negativas , Humanos , Proteína X Asociada a bcl-2 , Línea Celular Tumoral , Hipertermia Inducida , Campos Magnéticos , Nanopartículas de Magnetita/uso terapéutico , Mucina-1/genética , Factor 2 Relacionado con NF-E2 , ARN Interferente Pequeño/genética , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/terapia , Compuestos de Hierro , Nanopartículas Magnéticas de Óxido de HierroRESUMEN
Green synthesized magnetic nanoparticles were impregnated into biochar matrix (EWTWB) to produce biochar-supported magnetic nanocomposite (GSMB). Instead of chemicals, organic matters in white tea waste extract were used as reductant, surfactant and functional capping materials. Magnetic biochar produced from traditional methods of pyrolysis (PMB) and co-precipitation (Co-PreMB) were prepared to compare their properties with GSMB. Xray Diffraction confirmed the main component of green synthesized particles is Fe3O4. When compared with PMB and Co-PreMB, the Fe3O4 produced by co-precipitation method has higher purity while the products from green synthesis method are complex and contain a small portion of other iron-containing compounds. As a consequence, Co-PreMB has higher saturation magnetisation value than GSMB, which are 31.3 and 11.5 Am2/kg, respectively. GSMB was also found to be less stable in acidic conditions (pH ≤ 4) than Co-PreMB. However, the SEM results exhibited that spherical magnetic nanoparticles (20-50 nm) were successfully formed and distributed on the surface of biochar via green synthesis method while serious aggregation occurred on the surface of Co-PreMB. According to the result of BET, the surface area of GSMB increased dramatically from 0.2 m2/g to 59.7 m2/g. Fourier Transform Infrared spectroscopy and Xray photoelectron spectroscopy results showed the presence of rich oxygen-containing functional groups on the GSMB, The high surface area coupled with rich functional groups on the GSMB made the whole synthesis process an environmentally friendly and greener, to prepare magnetic biochar for application in wastewater treatment.
Asunto(s)
Compuestos de Hierro , Nanocompuestos , Magnetismo , Carbón Orgánico/química , Adsorción , Fenómenos Magnéticos , Té/química , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Soluble iron and sulfate in acid mine drainage (AMD) can be greatly removed through the formation of minerals facilitated by seed crystals. However, the difference in the effects of jarosite and schwertmannite as endogenous seed crystals to induce AMD mineralization remains unclear. This paper intends to study the effect of Fe2+ oxidation and Fe3+ mineralization in the biosynthesis of minerals using different addition amounts and methods of jarosite or schwertmannite. The results showed that the addition amount and method of different seed crystals had no effect on the Fe2+ bio-oxidation but would change the Fe3+ mineralization efficiency. With the same amount of seed crystals added, jarosite exhibited a higher capacity to promote Fe3+ mineralization than schwertmannite. Adding seed crystals before the initiation of Fe2+ oxidation (0 h) could significantly promote Fe3+ mineralization efficiency. With the increase of seed crystals, jarosite could not only shorten the time required for mineral synthesis but also improve the final mineral yield, whereas schwertmannite could only shorten the time required for mineral synthesis. When Fe2+ was completely oxidized to Fe3+ (48 h), the supplementary of jarosite could still effectively improve Fe3+ mineralization efficiency, but the addition of schwertmannite no longer affected the final mineralization degree.
Asunto(s)
Acidithiobacillus , Compuestos de Hierro , Hierro , Biomineralización , Compuestos de Hierro/química , Compuestos Férricos/química , Minerales , Oxidación-ReducciónRESUMEN
Iron (Fe) salt was applied extensively to remove phosphorus (P) in wastewater treatment plants (WWTPs). Exploring the formation mechanism of iron-phosphorus compounds (FePs) during the chemical P removal (CPR) process is beneficial to P recovery. In this study, the performance of P removal, FePs speciation analysis and the kinetics of P removal under different conditions (pH, Fe/P molar ratio (Fe/Pmol), type of Fe salt, dissolved organic matters) were comprehensively investigated. More than 95% of P was removed under the optimal conditions with pH = 4.7, Fe/Pmol = 2, FeCl3 or polymeric ferric sulfate (PFS) as the coagulant. The FePs formation mechanism was considerably influenced by reaction conditions. Iron-phosphate compounds were the dominant FePs species (>76%) at pH < 6.2, while more iron oxides were formed at pH ≥ 6.2 with decreased P removal efficiency. When the initial Fe/Pmol was 2, iron-phosphate compound was the only product that was formed by the reaction between PO43- and Fe(III) or Fe(II) ions directly. More iron oxides were generated when the initial Fe/Pmol was 1 or 3. At Fe/Pmol = 1, the Fe(III) was hydrolyzed to form iron oxides and trapped PO43-, while at Fe/Pmol = 3, iron-phosphate compounds were produced firstly and the remaining Fe(III) was hydrolyzed to form iron oxides. The pseudo-second-order kinetic model simulated the chemical P removal process well. The reaction rate of P with Fe(II) was slower than that with Fe(III), but complete removal was still achieved when the reaction time was more than 30 min. Poly-Fe salt exhibited a fast P removal rate, while the removal efficiency depended on its iron content. Organic matters in wastewater with large molecular weight and multiple functional groups (such as humic acids) inhibited P removal rate but hardly affect the removal amount. This study provides an insight into CPR by Fe salts and is beneficial for P recovery in WWTPs.
Asunto(s)
Compuestos Férricos , Compuestos de Hierro , Compuestos Férricos/química , Fósforo/química , Hierro/química , Fosfatos , Compuestos Ferrosos/química , Óxidos/químicaRESUMEN
The geochemical processes of polyphosphates (poly-Ps) are important for phosphorus (P) management and environmental protection. Water-soluble ammonium polyphosphate (APP) containing various P species has been increasingly used as an alternative P-fertilizer. The various P species coexistence and the chelation of poly-Ps with mental would trigger the P's competitive adsorption and affect the APP's adsorption intensity on goethite, compared to single orthophosphate (P1). P adsorption behaviors of APP1 with two P species and APP2 with seven P species on goethite were investigated via batch experiments in comparison to the traditional P-fertilizer of mono-ammonium phosphate (MAP). Coadsorption of P1 and pyrophosphate (P2) on goethite was investigated by molecular dynamics (MD) simulation. The more Fe3+ dissolved from goethite as a bridge due to the chelation of poly-Ps in APP and contributed to the stronger APP adsorption on goethite compared with MAP. Ion chromatography and spectral analysis showed P1 and P2 in APP were mainly adsorbed by goethite via mainly forming bidentate complexes. The goethite preferentially adsorbed P1 at lower APP concentration but increased the poly-Ps' adsorption at higher APP concentration. MD simulation showed that electrostatic interaction and hydrogen bonds played a key role in water-phosphates-goethite systems. The P1 pre-adsorbed on goethite could be replaced by P2 at high P2 concentration. The results develop new insights regarding the selective adsorption of various P species coexistence in goethite-rich environments.
Asunto(s)
Compuestos de Amonio , Compuestos de Hierro , Adsorción , Difosfatos , Fertilizantes , Concentración de Iones de Hidrógeno , Compuestos de Hierro/química , Minerales/química , Simulación de Dinámica Molecular , Fosfatos , Fósforo , Polifosfatos , Agua/químicaRESUMEN
Iron oxides play an important role in the transport and transformation of organic phosphorus in aquatic environments. However, the effect of different types of iron oxide on the environmental fate of organic phosphorus has remained unclear. In this study, the photodegradation of the organic phosphorus compound adenosine triphosphate (ATP) via the activity of crystalline (goethite) and amorphous (ferrihydrite) iron oxides was investigated. It was found that ATP was photodegraded by goethite, resulting in the release of dissolved inorganic phosphate under simulated sunlight irradiation. The concentration of ATP on goethite decreased by 75% after 6 h of simulated sunlight irradiation, while the concentration of ATP on ferrihydrite decreased by only 22%. ATR-FTIR spectroscopy revealed that the intensity of the peaks for the P-O and PO stretching vibrations in the goethite-ATP complex decreased significantly more after simulated sunlight irradiation than did those for the ferrihydrite treatment. Combined with the higher TOC/TOC0 values for the goethite treatment, the results indicate that a more vigorous photochemical reaction took place in the presence of goethite than with ferrihydrite. Reactive oxygen species analysis also showed that hydroxyl and superoxide anion radicals were generated when goethite was exposed to simulated sunlight irradiation, while ferrihydrite did not exhibit this ability. Overall, this study highlights that the type of iron oxide is an important factor in the transformation of organic phosphorus in aquatic environments.
Asunto(s)
Compuestos de Hierro , Fósforo , Adenosina Trifosfato , Compuestos Férricos/química , Hierro/química , Compuestos de Hierro/química , Minerales/química , Oxidación-Reducción , Fosfatos/química , Fósforo/química , Especies Reactivas de Oxígeno , Superóxidos , AguaRESUMEN
Previous studies have addressed the occurrence of Acid Rock Drainage (ARD) affecting La Silva stream due to the generation of large dumps of Middle Ordovician black shales during the construction of a highway close to El Bierzo (León, Spain). This ARD was characterized by sulphated acid waters with high concentration of heavy metals and anomalies in dissolved thorium (Th) and uranium (U). In the present study, we analyse in depth black shales and water, streambed sediments and precipitates of La Silva stream and its tributaries using different petrographic, mineralogical and geochemical approaches. Black shales, with average Th and U contents of 20 and 3 µg/g respectively contain disseminated detritic micro-grains of high weathering-resistant minerals, such as monazite and xenotime, that present smaller amounts of yttrium and rare earth elements (REY) and other elements as Ca, U, Th, Si and F. Results of the affected waters by ARD show an enrichment in dissolved Th, U and REY of several orders of magnitude with respect to natural waters. Sampled precipitates were mainly schwertmannite (Fe8O8(OH)8-2x (SO4)xO16â¢nH2O) and goethite (α-Fe3+O(OH)) that showed an enrichment of Th (up to 798 µg/g) and REY, due to the presence of dissolved anionic species (e.g. [Formula: see text] , [Formula: see text] ) that enables their adsorption. Furthermore, these black shales show a clear enrichment in REE (Rare Earth Elements) with respect to NASC (North American Shales Composite) normalized REE patterns. Likewise, normalized REE patterns of stream waters and precipitates clearly show convex curvatures in middle-REE (MREE) with respect to light- and something less than heavy-REE, indicating the trend towards MREE enrichment. These findings are essential to evaluate the impact of ARD of Mid Ordovician shales in the surrounding environment, and to start considering these site as potential source of REE and critical raw materials, activating a Circular Economy.
Asunto(s)
Metales de Tierras Raras , Uranio , Contaminantes Químicos del Agua , Ácidos/química , Monitoreo del Ambiente/métodos , Compuestos de Hierro , Metales de Tierras Raras/análisis , Minerales/análisis , Torio/análisis , Uranio/análisis , Agua/análisis , Contaminantes Químicos del Agua/análisis , Itrio/análisisRESUMEN
To improve the dose efficiency of K2FeO4 in waste activated sludge (WAS) treatment, pH regulation on K2FeO4 pretreatment and acidogenic fermentation was investigated. Four pretreatments were compared, i.e. pH3 + 50 g/kg-TS, pH10 + 50 g/kg-TS, neutral pH + 50 g/kg-TS and neutral pH + 100 g/kg-TS (without pH adjustment). The higher short chain fatty acids (SCFAs) yield and phosphorous dissolution rate was found under the condition of pH 10.0. In pH10 + 50 g/kg-TS, the maximum concentration of SCFAs was 5591 mg-COD/L, which yield was 22.6 times higher than that of the neutral pH + 50 g/kg-TS (237 mg COD/L). The acidogenic fermentation period could be shortened to 5 days and acetic acid accounted for 70 % of SCFAs. Furthermore, PO43--P in the hydrolysate (346.5 mg/L) accounted for 47.59 % of TP, which is easier to be recovered by chemical precipitation. Therefore, a more economical and feasible utilization mode of potassium ferrate was proposed.
Asunto(s)
Ácido Acético , Aguas del Alcantarillado , Ácidos Grasos Volátiles , Fermentación , Concentración de Iones de Hidrógeno , Compuestos de Hierro , Fósforo , Compuestos de PotasioRESUMEN
Acid mine drainage (AMD) contains abundant iron, sulfates, and various metal ions, and it causes environmental pollution. The traditional AMD lime neutralization forms a layer of iron hydroxide and gypsum on the surface of the lime particles, preventing continuous reaction and leading to excessive lime addition and neutralized sludge production. In this study, an approach for treating AMD using a cyclic process of biooxidation and electroreduction before lime neutralization was proposed, in which the Fe2+ in AMD was oxidized to Fe3+ and induced to form schwertmannite through Acidithiobacillus ferrooxidans. The remaining Fe3+ was reduced to Fe2+ using an electric field. After three biooxidation and two electroreduction cycles, 98.2% of Fe and 62.4% of SO42- in AMD precipitated as schwertmannite (Fe8O8(OH)5.16(SO4)1.37). The yield of schwertmannite reached 33.98 g/LAMD, with a high specific surface area of 112.59 m2/g. The lime dosage and sludge yield of the treated AMD in the subsequent neutralization stage (pH = 7.00) decreased by 85.0% and 74.5%, respectively, than those of raw AMD. The pilot test results showed that the integrated treatment of biooxidation-electroreduction cyclic mineralization and lime neutralization has practical applications.
Asunto(s)
Aguas del Alcantarillado , Contaminantes Químicos del Agua , Ácidos , Compuestos de Calcio , Concentración de Iones de Hidrógeno , Hierro , Compuestos de Hierro , Óxidos , Contaminantes Químicos del Agua/análisisRESUMEN
Iron fortification of foods has always been a challenge. This is because iron fortification compounds vary widely in relative absorption; because many foods undergo unacceptable changes in color or flavor from the addition of iron; and because many of the iron-fortified foods contain potent inhibitors of iron absorption. These technical barriers have largely been overcome, and efficacious iron-fortified foods, that maintain or improve the iron status of women or children in long-term feeding studies, can be designed. Commercially fortified infant foods are efficacious, and other commercial iron-fortified foods targeted at women and children will provide a useful amount of iron provided the fortification level is adjusted according to the relative absorption of the iron compound. Technologies for the large-scale fortification of wheat and maize flour are also well established, and iron fortification of rice, using the recently developed extruded premix technique, is showing great promise. However, some important knowledge gaps still remain, and further research and development is needed in relation to iron (and iodine)-fortified salt and iron-fortified liquid milk. The usefulness of less-soluble iron compounds, such as ferrous fumarate, to fortify foods for infants and young children in low- and middle-income countries (LMICs) also needs further investigation. A more formidable barrier to efficacious iron-fortified food has been reported in recent years. This is the infection-initiated inflammation barrier, which inhibits iron absorption in response to infection. This barrier is particularly important in LMICs where infections such as malaria and HIV are widespread, and gastrointestinal infections are common due to poor quality water supplies and sanitation. Another source of inflammation in such countries is the high prevalence of obesity in women. Most countries in sub-Saharan Africa have high inflammation which not only decreases the efficacy of iron-fortified and iron-biofortified foods but complicates the monitoring of large-scale iron fortification programs. This is because iron deficiency anemia cannot be differentiated from the more prominent anemia of inflammation and because inflammation confounds the measurement of iron status. There is an urgent need to better quantify the impact of inflammation on the efficacy of iron-fortified foods. However, at present, in LMICs with high inflammation exposure, infection control, cleaner water, improved sanitation, and a decrease in obesity prevalence will undoubtedly have a greater impact on iron status and anemia than the iron fortification of foods.
Asunto(s)
Anemia , Compuestos de Hierro , Niño , Preescolar , Femenino , Alimentos Fortificados , Humanos , Lactante , Inflamación , Hierro , ObesidadRESUMEN
The sorption process of radionuclides, often conducted at ambient temperature, shows significant sensitivity to the surrounding temperature. Prediction of fate and transport in the environment, therefore, requires accurate thermodynamic data of their species defining sorption-desorption onto solid surfaces. Herein, we examined the thermodynamics of uranium(VI), U(VI), sorption onto goethite with particular emphasis on directly calculating the enthalpy of U(VI) surface species formed under slightly acidic pH conditions. To achieve this aim, a sorption study of U(VI) was carried out on goethite in the pH range 3-10 and modelled using a 2-pK single-site diffuse layer surface complexation model. A binuclear bidentate species of U(VI), (îFeO)2UO2, reproduces the sorption profile at pH 3-5 while the sorption was under-estimated in the pH >5 region. Precipitation of schoeptite at pH 5-8 was attributed to the underestimation of the predicted sorption behaviour. The species complexation constant was employed in the analysis of heat consumed, measured using an isothermal titration calorimeter, in the titration of the goethite suspension with U(VI) at pH 4.5 ± 0.1. Enthalpy for the U(VI) species was found to be 41 ± 7 kJ mol-1, suggesting that sorption is an entropically driven process. Comparing thermodynamic data with that of similar U(VI)-iron oxide systems, binding energy of U(VI) surface species, surface hydration and hydrogen binding are suggested as main factors in the sorbent role towards the thermodynamics of the sorption process.
Asunto(s)
Uranio , Adsorción , Concentración de Iones de Hidrógeno , Compuestos de Hierro , Minerales , Termodinámica , Uranio/análisisRESUMEN
Abstract Preoperative anemia is a common finding. Preoperative allogeneic transfusion, iron therapy, vitamin supplementation and erythropoietin therapy are the current management strategies for preoperative anemia. Previous reviews regarding erythropoietin were limited to specialties, provided little evidence regarding the benefits and risks of erythropoietin in managing preoperative anemia and included non-anemic patients. The purpose of our systematic review was to determine the role of erythropoietin solely in preoperatively anemic patients and to investigate the complications of this treatment modality to produce a guideline for preoperative management of anemic patients for all surgical specialties. The PubMed/Medline, Google Scholar, and Cochrane Library were searched for randomized trials evaluating the efficacy of erythropoietin in preoperative anemia. The risk ratio (RR) and standardized mean difference (SMD) was used to pool the estimates of categorical and continuous outcomes, respectively. Allogeneic transfusion and complications and the 90-day mortality were the primary outcomes, while the postoperative change in hemoglobin, bleeding in milliliters and the number of red blood cell (RBC) packs transfused were the secondary outcomes. Results: Eight studies were included, comprising 734 and 716 patients in the erythropoietin group and non-erythropoietin group, respectively. The pooled estimate by RR for allogeneic transfusion was 0.829 (p = 0.049), while complications and the 90-day mortality were among the 1,318 (p = 0.18) patients. Conclusion: Preoperative erythropoietin provides better outcomes, considering the optimization of preoperative anemia for elective surgical procedures. The benefits of erythropoietin are significantly higher, compared to the control group, while the risks remain equivocal in both groups. We recommend preoperative erythropoietin in anemic patients.
Asunto(s)
Humanos , Eritropoyetina , Anemia , Transfusión Sanguínea , Cuidados Preoperatorios , Compuestos de Hierro/uso terapéuticoRESUMEN
Cadmium (Cd) and arsenic (As) contamination of paddy soils is a serious global issue because of the opposite geochemical behavior of Cd and As in paddy soils. Rice plant (Oryza sativa L.) cultivation in Cd- and As- contaminated paddy soil is regarded as one of the main dietary cause of Cd and As entry in human beings. This study aimed to determine the impact of goethite-modified biochar (GB) on bioavailability of both Cd and As in Cd- and As- polluted paddy soil. Contrary to control and biochar (BC) amendments, the application of GB amendments significantly impeded the accumulation of both Cd and As in rice plants. The results confirmed an obvious reduction in Cd and As content of rice grains by 85% and 77%, respectively after soil supplementation with GB 2% amendment. BC 3% application minimized the Cd uptake by 59% in the rice grains as compared to the control but exhibited a little impact on As accumulation in rice grains. Sequential extraction results displayed an increase in immobile Cd and As fractions of the soil by decreasing the bioavailable fractions of both elements after GB treatments. Fe-plaque formation on the root surfaces was significantly variable (P Ë 0.05) among all the amendments. GB 2% treatment significantly increased the Fe content (10 g kg-1) of root Fe-plaque by 48%, which ultimately enhanced the sequestration of Cd and As by Fe-plaque and minimized the transport of Cd and As in rice plants. Moreover, GB treatments significantly changed the relative abundance of the microbial community in the rice rhizosphere and minimized the metal(loid)s mobility in the soil. The relative abundance of Acidobacteria, Firmicutes and Verrucomicrobia increased with GB 2% treatment while those of Bacteroidetes and Choloroflexi decreased. Our findings confirmed improvement in the rice grains quality regarding enhanced amino acid contents with GB application. Overall, the results of this study demonstrated that GB amendment simultaneously alleviated the Cd and As concentrations in edible parts of rice plant and provided a new valuable method to protect the public health by effectively remediating the co-occurrence of Cd and As in paddy soils.
Asunto(s)
Arsénico , Oryza , Contaminantes del Suelo , Arsénico/análisis , Cadmio/análisis , Carbón Orgánico , Humanos , Compuestos de Hierro , Minerales , Oryza/química , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
PIII-containing H-phosphonate (HPO32-) and its monoethyl ester (fosetyl), essential pesticides for control of oomycete and fungal pathogens, are among the few pesticides transported by both xylem and phloem, making application as folia spray, soil spray, and trunk injection equally effective. To understand bioavailability and efficacy within soils, knowledge of adsorption to soil minerals is important. FeOOH(goethite) is often selected as an archetypal mineral surface. In the present work, H-phosphonate (with pKa values of 1.5 and 6.78) adsorption onto FeOOH is nearly complete below pH 6 and decreases to negligible amounts by pH 11, following an S-shaped curve. Fosetyl (pKa: 0.9), in contrast, does not adsorb to any significant extent, regardless of pH. To place these observations in context, adsorption of six other phosphorus oxyanions was investigated, and fitted using a CD-MUSIC model. Phosphate defines a similar S-shaped curve but adsorbs more strongly than H-phosphonate. Despite moderate differences in basicity, pH dependence and extents of adsorption for the four additional diprotic oxyanions methylphosphonate (pKas: 2.40, 8.00), benzylphosphonate (2.24, 7.93), phenylphosphonate (1.9, 7.47), and phenyl phosphate (1.1, 6.28) are quite similar to those of H-phosphonate. As with fosetyl, the other low pKa monoprotic oxyanion in our study, phenylphosphinate (pKa: 1.75), does not adsorb. Basicity, that is, pKa, is revealed to be the principal determinant of extents of adsorption.
Asunto(s)
Compuestos de Hierro , Fósforo , Adsorción , Concentración de Iones de Hidrógeno , Minerales , AguaRESUMEN
Iron-refractory iron deficiency anemia (IRIDA) is an autosomal recessive disorder caused by genetic mutations on TMPRSS6 gene which encodes Matriptase2 (MT2). An altered MT2 cannot appropriately suppress hepatic BMP6/SMAD signaling in case of low iron, hence hepcidin excess blocks dietary iron absorption, leading to a form of anemia resistant to oral iron supplementation. In this study, using the IRIDA mouse model Mask, we characterized homozygous (msk/msk) compared to asymptomatic heterozygous (msk/wt) mice, assessing the major parameters of iron status in different organs, at different ages in both sexes. The effect of carbonyl iron diet was analyzed as control iron supplementation being used for many studies in mice. It resulted effective in both anemic control and msk/msk mice, as expected, even if there is no information about its mechanism of absorption. Then, we mainly compared two forms of oral iron supplement, largely used for humans: ferrous sulfate and Sucrosomial iron. In anemic control mice, the two oral formulations corrected hemoglobin levels from 11.40 ± 0.60 to 15.38 ± 1.71 g/dl in 2-4 weeks. Interestingly, in msk/msk mice, ferrous sulfate did not increase hemoglobin likely due to ferroportin/hepcidin-dependent absorption, whereas Sucrosomial iron increased it from 11.50 ± 0.60 to 13.53 ± 0.64 g/dl mainly in the first week followed by a minor increase at 4 weeks with a stable level of 13.30 ± 0.80 g/dl, probably because of alternative absorption. Thus, Sucrosomial iron, already used in other conditions of iron deficiency, may represent a promising option for oral iron supplementation in IRIDA patients.
Asunto(s)
Anemia Ferropénica/terapia , Compuestos Férricos/uso terapéutico , Compuestos Ferrosos/uso terapéutico , Compuestos de Hierro/uso terapéutico , Hierro de la Dieta/uso terapéutico , Administración Oral , Anemia Ferropénica/metabolismo , Animales , Modelos Animales de Enfermedad , Femenino , Compuestos Férricos/administración & dosificación , Compuestos Ferrosos/administración & dosificación , Humanos , Hierro/metabolismo , Compuestos de Hierro/administración & dosificación , Hierro de la Dieta/administración & dosificación , Masculino , RatonesRESUMEN
The atherosclerosis "iron hypothesis" generates a fair amount of debate since it has been proposed. Here, we revisited the "iron hypothesis" by examining whether dietary iron overload would intensify iron deposition in plaques and thus lead to further exacerbation of atherosclerosis in apolipoprotein E knockout (ApoE KO) mice. ApoE KO mice were fed either a normal chow diet (ND) or a high fat diet (HFD) supplemented with or without 2% carbonyl iron (Fe) for 16 weeks. However, contrary to our assumption, dietary iron overloading did not intensify, but rather diminished the atherosclerotic lesion area by 65.3%, which was accompanied by significantly decreased serum total cholesterol, triglyceride and low-density lipoprotein cholesterol contents, together with hepatic lipid accumulation decline, despite the evident existence of aortic iron accumulation and the typical signs of iron overload in ApoE KO mice. Using isobaric tag for absolute quantification (iTRAQ) proteomics approach, hepatic CD36 and fatty acid binding proteins-mediated fatty acid (FA) uptake and trafficking impairment were identified as the key potential pathomechanisms by which iron overload diminishes atherosclerotic lesions. Furthermore, downstream hepatic FA de novo biosynthesis was enhanced and FA oxidation was inhibited to compensate for the FA deficiency triggered by iron overload-impaired fatty acid uptake and trafficking. Our findings suggested that dietary iron overload is not atherogenic in ApoE KO mice, and more research efforts are warranted to revisit the "iron hypothesis" of atherosclerosis.