Extra Iron Research Articles

Iron-based magnetic nanocomplexes for combined chemodynamic and photothermal cancer therapy through enhanced ferroptosis

Chemodynamic therapy (CDT) guided by Fenton chemistry and iron-containing materials can induce ferroptosis as a prospective cancer treatment method, but the inefficient Fe3+/Fe2+ conversion restricts the monotherapeutic performances. Here, an iron-based nanoplatform (Fe3O4-SRF@FeTA) including a magnetic core and a reductive film is developed for combined CDT and photothermal therapy (PTT) through ferroptosis augmentation. The inner iron oxide core serves as a photothermal transducer, a magnet-responsive module, and an iron reservoir for CDT. The coated Fe3+-tannic acid film (FeTA) provides extra iron and reductants for Fe3+/Fe2+ conversion acceleration, and functions as a door keeper for the pH- and light-responsive release of the embedded ferroptosis inducer sorafenib (SRF). The in vitro results demonstrate that the iron-based nanocomplexes promote the production of lipid peroxide through the amplified Fenton activity, and downregulate glutathione involved in lipid peroxide repair system through the responsively released SRF. Upon accumulation in tumor by magnetic targeting and sequential laser irradiation locoregionally, Fe3O4-SRF@FeTA nanocomplexes present prominent in vivo anticancer efficacy by leveraging PTT and CDT-enhanced ferroptosis.

Role of Exergy‐Based Process Evolution for Sustainable Steel Making: Rotary Hearth Furnace with Electric Arc Furnace Smelting

In conjunction with an electric arc furnace (EAF) process, a rotary hearth furnace (RHF) has emerged as a supplementary ironmaking unit to produce extra iron from iron‐bearing solid wastes from an integrated steel plant. Additionally, such units offer fuel‐switching options to low‐carbon input fuels. Exergy analysis is carried out for two variants of RHF, producing iron nuggets (ironmaking technology mark 3 process) or direct reduced iron (DRI; FASTMET process), involving cold/hot charging of DRI and scrap use in EAF. Process sustainability as characterized by higher exergy efficiency and lower CO2 emission has been analyzed for two variants of RHF‐EAF steelmaking systems, blast furnace‐basic oxygen furnace (BOF), scrap‐EAF, and COREX‐BOF process. Model‐based information for these parameters for RHF‐EAF process has been compared with other major steelmaking routes based on literature information. The RHF‐EAF process variants with some modification in process flow display better sustainability with relatively higher exergy efficiencies and low CO2 emissions as compared to other steelmaking processes and reasonably meet sustainable steelmaking process evolution criterion.

Rock magnetic analyses as a tool to investigate diversity of drift pumice clasts: An example from Japan's 2021 Fukutoku‐Oka‐no‐Ba (FOB) eruption

AbstractThe crystallization of nanolites within magma chambers has recently raised a strong interest due to their impact on increasing melt viscosity and triggering magmatic eruptions. In 2021, the Fukutoku‐Oka‐no‐Ba (FOB) underwater eruption produced large quantities of pumices that eventually formed rafts drifting at the surface of the ocean to the East coasts of Japan. Pumices collected along the shore shortly after grounding show various colors, microscopic and Raman analyses made by Yoshida et al. (Island Arc, 31, 1, 2022) revealed the presence of magnetite nanolites in some of them. In this study, we explore the magnetic properties of a batch of pumices of different colors from the FOB eruption, aiming to refine characterization of iron oxide nanolites. We used various analytical techniques such as SEM and FEG‐SEM observations, EDS‐X analyses, and rock magnetic experiments, including thermomagnetic analyses, hysteresis curves, coercivity analyses and FORC measurements. Our findings reveal that the iron oxides present in the FOB samples are Ti‐magnetite, with minor amounts of Mg and Al. The magnetic crystals show a wide range of sizes, from extra small iron oxide nanolites (ESION) in the pumices with the lighter colors, to more bulky grains reaching the micrometer size in some of the dark color samples, significant diffusion is inferred in that case. Consequently, the magnetic characterization of iron oxide crystals within the Fukutoku‐Oka‐no‐Ba pumices reveals varying stages of nucleation, dissolution, growth, and diffusion processes, providing evidences for the heterogeneous state of the magma during the eruption.

The role of iron and ferroptosis in the pathogenesis of acute pancreatitis

ABSTRACT Acute pancreatitis (AP) is an inflammatory disease of the pancreas. Iron is an essential element for life and is involved in many metabolic processes. Ferroptosis is a type of regulated cell death that is triggered by iron and oxidative stress. A well-established mouse AP model was adopted to study the role of iron and ferroptosis in the pathogenesis of pancreatitis. Mice were injected with cerulein to induce AP, and pancreatic tissue samples were analyzed to determine the pathology, cell death, iron deposition, expression of iron transporters, and lipid peroxidation. The role of iron was studied by giving mice extra iron or iron chelator. In vitro studies with acinar cells with ferroptosis activator and inhibitor were also performed to assess the inflammatory response. Iron was found accumulated in the pancreatic tissue of mice who suffered cerulein-induced pancreatitis. Cell death and lipid peroxidation increased in these tissues and could be further modulated by iron dextran or iron chelator. Mice given Hemin through gavage had reduced levels of GSH in pancreatic tissue and increased inflammatory response. Studies with acinar cells showed increased levels of lipid peroxidation and ferroptosis-specific mitochondrial damage when treated with ferroptosis inducer and inflammatory cytokines.

Fe(Ⅲ) concentrations controlled highly soluble carboxylated inulin–Fe toward efficient supplement of iron

Iron deficiency is the utmost critical problem of nutrition worldwide. Polysaccharide-iron chelate is a promising iron supplementation that exhibits good stability, high absorption rate, and fewer adverse reactions, but it still owns drawbacks of extra energy and lower iron content with respect to inorganic ones. Carboxylated polysaccharide-iron has been proven with enhanced iron content, however with poor aqueous solubility. Here, Fe3+ concentrations controlled highly soluble carboxylated inulin-iron chelates were synthesized to promote the sustained release and efficient supplement of iron with no extra energy. Inulin, soluble dietary fiber, was initially reacted with succinic anhydride (SA) to get carboxylated inulin (IN-SA) consequently enhancing the complexing ability of Fe3+ and its bioavailability. Interestingly, the aqueous solubility of the IN-SA-iron chelate (IN-SA-Fe) directly correlated with the Fe3+ concentrations. Relatively higher or lower Fe3+ concentrations resulted in highly soluble IN-SA-Fe, otherwise, leading to insolubility precipitates. The possible mechanism was proposed as the polymerization reaction of IN-SA in different degrees with Fe3+ acting as the cross-linker. Moreover, IN-SA-Fe was demonstrated with properties of sustained slow-release of iron in artificial gastric juice and good in vivo biosafety. This work provides a simple, efficient, no extra energy soluble iron supplement for the treatment of iron deficiency.

Hypogene enrichment in Miduk porphyry copper ore deposit, Iran

This study was planned with the aim of identifying the nature and circumstances of the high-graded central core and increasing trend of copper content through depth of 1000 m in Miduk PCD. Mechanisms of high-grading, refer to hypogene enrichment (HE), in PCDs poorly understood. Two main hypotheses for hypogene enrichment formation assumed addition of extra copper to the system, alternatively hypogene leaching and enrichment. In order to obtain alteration-mineralization-geochemical pattern both horizontally and vertically, all macroscopic data extracted from relogging of 6800 m’ drill core along an east–west profile, compiled with microscopic observations from studying of 550 thin-polished sections and copper grades of 3400 samples analyzed by XRF and ICP-OES. Our findings proved hypogene enrichment events at deposit. HE evidences in macroscopic and microscopic scales identified almost as various replacement textures between Fe-Cu sulphides and also vein-reopening by later Cu-mineralization and new generation of disseminated or vein type mineralization. In addition, appearance of dark halo, as consuming intermediate chalcocite phase, around pyrite and chalcopyrite which gradually evolves as bornite, also extruding extra iron as fibrous hematite at the outer edge of bornite product replaced chalcopyrite, partially replacement of bornite and chalcopyrite to hypogene chalcocite and covellite-digenite in deep potassic are other HE evidences in the case study. Here, we draw on microscopic observations and SEM-BSE-EDS results, secondary hypogene genesis for some of bornite and chalcopyrite as a hypogene enrichment evidence. Observations from relogging show that potassic alteration has a relatively good preservation in the center of the deposit from depth to surface, but affected by intense overprinting of subsequent alterations towards margins. Evident function of ore-leaching at margins, also elevated copper grades in central parts of the deposit strongly suggest leaching-fixation mechanism. Where buffer potential of the rock is preserved copper fixation and where it totally eliminated almost complete leaching of copper happened. Consequently, we introduce leaching-fixation as index processes in hypogene enrichment at the case study. We suggest that identifying the nature of hypogene enrichment processes and its characterizations not only improve understanding about PCD’s hydrothermal evolution, but also achieve exploration indicators, furthermore, industrial benefits in the production line.

Dietary Iron Unlikely to Cause Insulin Resistance in Horses.

Racehorses are often supplemented extra iron with the expectation that the iron will improve overall performance and health. A survey of 120 U.S. Thoroughbred trainers, representing 1978 Thoroughbreds from various regions of the U.S., was conducted to determine the average amount of dietary iron fed to Thoroughbred racehorses per day. Survey results indicated racehorses were fed an average of 3900 mg of iron per day from hay and grain alone. This exceeds the 0.8 mg/kg BW or 400 mg for a 500 kg working horse that the NRC 2007 recommends per day. Supplements increased the daily average intake of iron by an additional 500 mg Fe. Some equine nutritionists propose that excess dietary iron may be a causative factor in insulin resistance (IR). However, the occurrence of IR in Thoroughbred racehorses is very rare. This study did not find one confirmed veterinary diagnosis of IR in any of the surveyed trainers' Thoroughbred horses, whether racing, on a layoff, or retired. Given the iron content in these diets easily exceeds the NRC minimum daily requirements, it seems unlikely that dietary iron is an independent causative factor in IR.

Contribution Factors on Long- term and Short- term Survival of Thalassemia Major Patients

Introduction: Thalassemia major is an important health problem in Mediterranean countries that causes many psychological and economic problems. This study aimed to evaluate the effective factors on long- and short-term survival of thalassemia major patients using mixture and non-mixture cure survival models based on Generalized Gompertz distribution. The Generalized Gompertz distribution has flexible curve of failure rate that may be appropriate for different situation of survival analysis.
 Methods: In this retrospective cohort study, medical records of 300 thalassemia major patients referring to Zafar's thalassemia clinic during 1994-2017 in Tehran, Iran were reviewed. Mixture and non-mixture cure survival models based on Gompertz and Generalized Gompertz distributions were performed to estimate the effective factors on long- term and short- term survival of Thalassemia Major Patients. The Akaike Information Criteria (AIC) was used to compare the models. Analysis was performed using SAS software version 9.4.
 Results: The mean (±SD) survival time was 32.21 (±7.47) years. The censorship rate was 78.30%. In both of the mixture and non-mixture cure models, Generalized Gompertz distribution, as compared to the standard Gompertz had the lower Akaike criteria that was 200.8. Based on this model, iron deposition in liver at mild and moderate levels had a significant effect on the long-term survival of these patients.
 Conclusion: Based on Akaike Information criteria, considering the Generalized Gompertz mixture cure model has the best fit for the data of thalassemia major disease in which patients are long-term survivors. In order to analyze the survival of patients with thalassemia major, since iron deposition in liver at mild and moderate levels had a significant effect on the long-term survival of these patients; it is recommended to apply a regular iron chelation therapy for extra iron excretion.

Iron homeostasis of liver-gut axis alleviates inflammation caused by dietary cottonseed meal through dietary Fe2+ supplementation in juvenile grass carp (Ctenopharyngodon idellus)

This study aimed to explore whether Fe2+ supplementation can improve the ability of grass carp to tolerate a high content of dietary cottonseed meal (CSM) and, if so, to uncover the potential regulation mechanism involved. Soybean and rapeseed meals were used as the main protein materials for the feed diet low in free gossypol (LFG) while CSM predominated in the diet high in free gossypol (HFG). In two other treatments, amounts of FeSO4•7H2O were supplemented in HFG diets to configure an HFG + Fe1 diet (containing supplementary 400 mg/kg of Fe2+) and an HFG + Fe2 diet (800 mg/kg of Fe2+). The experimental diets were randomly assigned to 12 cages, in triplicate, for an 8-week feeding trial. The results showed that fish fed the HFG diet had lower levels of PER (P < 0.05) than that fed the LFG diet. The greatest values for FBW, WGR, SGR, PER, and FCR were recorded in the HFG + Fe2 group, all differing significantly from the HFG group (P < 0.05). Meanwhile, the HFG + Fe2 diet conspicuously improved the lipid-deposition induced by HFG (P < 0.05). Fish fed the HFG diet showed lower levels of iron contents both in their blood (P > 0.05) and liver (P < 0.05) than did the LFG group, whereas the HFG + Fe2 diet increased them (P < 0.05) to maintain iron homeostasis by up-regulating hepcidin (P < 0.05) and down-regulating fpn1 mRNA (P < 0.05). The HFG + Fe2 diet also down-regulated the expression level of il-1β, and increased that of two anti-inflammatory cytokines, il-11 and tgf-β1, all of which differed significantly from those of the LFG group (P < 0.05). Compared with the LFG group, mRNA expression levels of jam-a and claudin-b in the HFG group were inhibited significantly (P < 0.05), but increasing the Fe2+ supplementation up-regulated expression levels of intestinal tight junctions, such as zo-1, zo-2, jam-a, occludin, claudin b, and claudin c. Altogether then, the inclusion of dietary Fe2+ supplementation (1–2:1 ratio of extra iron to free gossypol) augmented the tolerance to the high content of dietary CSM in grass carp by alleviating the intestinal inflammatory and restoring intestinal barrier function through iron homeostasis regulation.

Elemental sulfur generated in situ from Fe(III) and sulfide promotes sulfidation of microscale zero-valent iron for superior Cr(VI) removal

Herein, we compared the effect of different extra iron and sulfur precursors on the sulfidation efficiency, physicochemical properties, and reactivity of post-sulfidated microscale zero-valent iron (S-ZVI). S0@ZVI was synthesized from in situ S0 generated via reaction of Fe(III) with S2-, which resulted in 23-fold higher Cr(VI) removal compared with S0com/ZVI synthesized using commercial S0. The direct formation of FeSx film via reaction between S0 and ZVI played a crucial role in enhancing the removal of Cr(VI) by S0@ZVI, with 16- and 12-fold faster rates compared with FeS@ZVI and FeS2@ZVI prepared via precipitated reaction of Fe(II) with S2- and sulfur mixtures, respectively. The incorporated sulfur, sulfidation sequence, and sulfidation time determined the performance of S0@ZVI. A combination of batch experiments and kinetic models was used to determine the chemical composition of reduced Cr(VI) products. S0@ZVI immobilized Cr(VI) as Fe0.5Cr0.5(OH)3 via surface heterogeneous reactions, and partial Cr(VI) was homogeneously reduced to soluble Cr(acetate)3 or Fe0.75Cr0.25(OH)3(aq) by dissolved Fe(II). The insights gained from this study will facilitate the fabrication of highly reactive S-ZVI and elucidate the mechanism of Cr(VI) removal.

Cupping Therapy (حجامه) in the view of Islamic teaching

The term "cupping therapy" refers to treatments that involve applying sucking cups to specific skin regions for therapeutic reasons. Cupping therapy is a straightforward, risk-free, comfortable, efficient, cost-effective, and time-saving procedure. Traditional wet cupping therapy is a two-step process that involves cupping first, then superficially scarifying the skin (also known as the double S technique). Traditional wet cupping therapy was found to be successful in treating carpal tunnel syndrome in a German study. Al-hijamah is a three-step method that involves wet cupping therapy in prophetic medicine (suction, scarification, and suction technique, ie, triple S technique). According to the evidence-based Taibah mechanism, al-hijamah is a successful excretory therapy that purges the blood and interstitial spaces of harmful pathogenic chemicals. we firmly advocated Al-hijamah in our earlier articles for normal medical practice in hospitals. Al-hijamah was strongly advised for the treatment of thalassemia. In healthy people, al-hijamah dramatically reduced serum ferritin levels. Al-hijamah is an excretory procedure that considerably purges blood of harmful chemicals. Thalassemia may be a good candidate for treatment with Al-hijamah to remove extra iron and ferritin from thalassemic blood (via percutaneous iron excretion), as we mentioned in earlier papers. Al-hijamah is a brand-new percutaneous iron excretion therapy (PIET), which we will explore in this article. Interestingly, despite their distinct etiologies and pathophysiology, autoimmune disorders and migraine headaches responded favorably to al-hijamah treatment.

Importance of Iron Metabolism

Iron is a vital micronutrient that is mandatory for fundamental processes in both humans and bacteria. Iron is an essential trace element which promotes cell proliferation and growth. It also has the potential to initiate redox cycling and free radical synthesis. Hence, it is engaged in initiating tumorigenesis, its microenvironment and metastasis. Acquisition of iron, efflux, storage and regulation pathways are disturbed in carcinogenesis which suggests a reprogramming role of iron metabolism in tumor cell survival. Targeting iron metabolic pathways may give a new insight for prognosis and therapy [1].&#x0D; Globally many people suffer from iron overload toxicity diseases e.g. trans fusional iron overload in thalassemia and hereditary haemochromatosis. Accumulated toxic iron deposits can cause tissue damage and identified in neurological disorders as well such as Alzheimer’s and Parkinson’s [2]. Regulation of iron is an essential defense mechanism against microbial infections. Individuals with toxic iron overload are more prone to bacterial infections as it is up taken by bacteria for their growth and survival [3]. These bacteria release iron binding molecules and then resorb them to recover iron deficiency. They also get rid of extra iron from transportation and hemoglobin. Microbes face more metabolic pressure when they have to strive hard to acquire it. Hence, the microbes with iron deficiency have a slower rate of reproduction as compared to others [5]. A small amount of iron is lost by sweating and shedding of cell from skin as well as mucosal lining of the digestive tract. However, most of it is restored and recycled by the reticuloendothelial system, which also breaks down the red blood cells [6].&#x0D; Iron homeostasis is perturbed in inflammation and sepsis, causing raised iron transportation, influx into cells and reduction in iron efflux. Iron may be used as a predictive and diagnostic marker to evaluate the severity of diseases related to iron metabolism, sepsis and inflammation. Further studies are required to explore the drugs targeting specifically to iron metabolic pathways and providing an optimal therapeutic opportunity [7].

Environmental Determinants of Malaria Prevalence and the Adaptation Strategies in Western Nepal.

Current literatures seem devoted only on relating climate change with malaria. Overarching all possible environmental determinants of malaria prevalence addressed by scanty literature in Nepal is found apposite research at this moment. This study aims to explore the environmental determinants of malaria prevalence in western Nepal. Cross-sectional data collected from community people were used to identify the environmental determinants of malaria prevalence in western Nepal. Probit and logistic regressions are used for identifying determinants. The results reveal that environmental variables: winter temperature (aOR: 2.14 [95% CI: 1.00-4.56]), flooding (aOR: 2.45 [CI: 1.28-4.69]), heat waves (aOR: 3.14 [CI: 1.16-8.46]) and decreasing river water level (aOR: 0.25 [CI: 0.13-0.47]) are found major factors to influence malaria prevalence in western Nepal. Besides, pipeline drinking water (aOR: 0.37 [0.17-0.81]), transportation facility (aOR: 1.18 [1.07-1.32]) and awareness programs (aOR: 2.62 [0.03-6.65]) are exigent social issues to influence malaria prevalence in Nepal. To be protected from disease induced by environmental problems, households have used extra season specific clothes, iron nets and mosquito nets, use of insecticide in cleaning toilet and so on. Adaptation mechanism against these environmental issues together with promoting pipeline drinking water, transportation facility and awareness programs are the important in malaria control in Nepal. Government initiation with incentivized adaptation mechanism for the protection of environment with caring household attributes possibly help control malaria in western Nepal.

Exploring selected pathways to low and zero CO2 emissions in China's iron and steel industry and their impacts on resources and energy

The increasing energy and material consumption associated with global economic growth has resulted in the need for more severe efforts at mitigating global climate change. The iron and steel industry consumes 8% of energy and emits 7% of total CO2 globally. China's iron and steel industry contributes to 15% of that country's total CO2 emissions. Therefore, there is an urgent need to explore the possibility of net zero emissions in the iron and steel industry in China to meet China's goal of carbon neutrality before 2060. In the study presented in this paper, the MESSAGEix–China iron and steel model was developed by integrating the process-based technology of the sector into the IIASA's MESSAGEix framework to explore zero CO2 emission pathways and their associated impacts on resources, energy, and water in China's iron and steel industry up to 2100. We found that there are multiple pathways to achieving zero CO2 emissions in the Chinese iron and steel industry by the end of the 21st century. More specifically, in all the pathways developed in this study, CO2 emissions decreased significantly between 2030 and 2060 due to the rapid application of 100% scrap-based Electric Arc Furnaces (EAFs) and hydrogen-based Direct Reduced Iron (DRI)-EAFs steel-making technologies. However, by 2060, there will still be 70–360 Mt of CO2 emissions from China's iron and steel industry; consequently, carbon sink or negative emission technologies are required to offset this and achieve the country's carbon neutrality goal. Furthermore, technologies for achieving zero emissions differ widely in terms of their impacts on the consumption of materials and energy. Compared to the electric (ELE) scenarios, 25–40% of extra iron ore is consumed in the current and new national policy (NPS) scenarios and the DRI scenarios, but 25–220% of scrap is required. At the same time, 20–150% more energy will be saved in the ELE scenarios than in the NPS and DRI scenarios. Finally, we recommend that policy makers design a cross-cutting strategy to achieve zero CO2 emissions and enhance efforts for material recycling and the provision of clean energy and water.

Enhanced Cr (VI) removal with Pb (II) presence by Fe2+-activated persulfate and zero-valent iron system

ABSTRACT Combined heavy metals such as chromium (Cr (VI)) and lead (Pb (II)) in natural water have globally posed severe environmental and public health risk. Here the removal of Cr (VI) and Pb (II) mixed pollutants using Fe2+-activated persulfate (PS) with extra zero-valent iron (ZVI), which was not only a supplementary Fe2+ source, but also a high-efficiency absorbent, was investigated. During removal, pivotal factors of initial pollutant concentration, dosages of ZVI and PS, initial pH and temperatures were examined. Interestingly, generating a lot of H+ in the process of Fe (II) activating persulfate were helpful to the corrosion of ZVI over a large range of pH (1–9). Under the optimum condition, removal efficiency of Pb (II) and Cr (VI) have reached 100% and 94.26% respectively. The removal mechanism was suggested as a three-step reaction that the Pb (II) boosted the removal of Cr (VI) by co-precipitated in wastewater, and the Pb (II) and Cr (VI) were adsorbed and subsequently reduced to Pb0 and Cr3+ as Cr(OH)3 or Cr3+-Fe3+ hydroxides on ZVI surface. Cr (VI) and Pb (II) adsorption kinetics agreed with the pseudo-second-order reaction rate expression. In addition, we were surprised to found that the contribution effect of chromium and lead co-precipitation for their removal by Fe (II) – PS-ZVI has strong dependence on initial pH and concentration ratio of Cr (VI) and Pb (II). The result indicated that Fe (II)-PS-ZVI system should be a favourable removal technology for Cr (VI) and Pb (II).

Insights into the synthesis optimization of Fe@SiO2 Core-Shell nanostructure as a highly efficient nano-heater for magnetic hyperthermia treatment

Maintaining the intact iron core, protecting the extra iron ion release, and generating biologically sufficient heat, are the critical aspects for magnetic hyperthermia treatment (MHT). Thus, the composition of silica-coated nanoscale zero-valent iron (nZVI) was optimized by applying response surface methodology (RSM) and changing the molar ratio of tetraethyl orthosilicate (TEOS) and iron(II) sulfate (FeSO4·7H2O) as the silica and iron precursors, respectively. The TEOS/FeSO4·7H2O molar ratio of 1.67 results in the maximized saturation magnetization (99.3 emu/g) and the crystalline phase of pure iron. In comparison with the previously reported studies, the synthesized core–shell nanostructures demonstrate superior heat production features. As silica coating protects the inner core from oxidation and results in more effective heat-generating seeds, nanostructures with a higher amount of silica precursors, i.e., 10.3 mm, demonstrate an efficient specific absorption rate (SAR). Moreover, the medium and higher TEOS amounts represent acceptable cytocompatibility up to 125 μg/mL and 250 μg/mL, respectively. In vitro hyperthermia evaluation depicts the cancer cell viability reduction indicating the hyperthermia-induced apoptosis. Based on the data mentioned above, we could introduce a potential successful nanoparticle for magnetic hyperthermia treatment.

Identification of cbiO Gene Critical for Biofilm Formation by MRSA CFSa36 Strain Isolated from Pediatric Patient with Cystic Fibrosis.

The colonization of Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), has a detrimental effect on the respiratory care of pediatric patients with cystic fibrosis (CF). In addition to being resistant to multiple antibiotics, S. aureus also has the ability to form biofilms, which makes the infection more difficult to treat and eradicate. In this study, we examined the ability of S. aureus strains isolated from pediatric patients with CF to form biofilms. We screened a transposon mutant library of MRSA and identified a putative cobalt transporter ATP binding domain (cbiO) that is required for biofilm formation. We discovered that deleting cbiO creating a cbiO null mutant in CFSa36 (an MRSA strain isolated from a patient with cystic fibrosis) significantly hinders the ability of CFSa36 to form biofilm. The complementation of cbiO restored the ability of the cbiO deletion mutant to generate biofilm. Interestingly, we revealed that incorporating extra copper ions to the chemically defined medium (CDM) complemented the function of cbiO for biofilm formation in a dose-dependent manner, while the addition of extra iron ions in CDM enhanced the effect of cbiO null mutation on biofilm formation. In addition, neither the addition of certain extra amounts of copper ions nor iron ions in CDM had an impact on bacterial growth. Taken together, our findings suggest that cbiO mediates biofilm formation by affecting the transportation of copper ions in the MRSA CFSa36 strain. This study provides new insights into the molecular basis of biofilm formation by S. aureus.

A self-sufficient electro-Fenton system with enhanced oxygen transfer for decontamination of pharmaceutical wastewater

The need for extra iron catalyst, limited selectivity of the oxygen reduction reaction (ORR) to produce H2O2, and harsh pH applicability still plague the electro-Fenton (EF) process. To alleviate these concerns simultaneously, a novel self-sufficient EF system was constructed, in which the newly fabricated Fe, N and S co-doped cathode was aerated via microporous aeration and a greater number of cathodes was utilized. Results indicated that the prepared cathode achieved a high H2O2 accumulation (15.60 ± 0.16 mg L−1 cm−2) coupled with nearly 90% H2O2 selectivity. The microporous aeration tube, which delivered microbubbles and changed the diffusion direction to supply more O2 to the electrode active sites, is beneficial to the H2O2 formation. Apart from its high H2O2 accumulation, the proposed system was set up to automatically reduce the bulk pH by regulating different current densities on electrodes. The proposed EF system was employed to treat real pharmaceutical wastewater, in which ·OH, 1O2, ·O2− and Fe(IV) were the main active species. Finally, an improvement of BOD5/COD values after EF treatment was a good indicator to confirm the feasibility of the developed system as a pretreatment prior to the subsequent engineering applications.

In situ produced hydrogen peroxide by biosynthesized Palladium nanoparticles and natural clay mineral for Highly-efficient Carbamazepine degradation

Fenton reaction is an effective method to remove refractory organics such as carbamazepine (CBZ) from water streams. Nevertheless, its application is greatly compromised by extra hydrogen peroxide (H2O2) addition and iron mud accumulation. Herein, Fenton-like process with in situ produced H2O2 by biosynthesized palladium nanoparticles (bioPd-NPs) and natural iron-bearing clay minerals is proposed for CBZ degradation. The bioPd-NPs prepared by Shewanella loihica PV-4 were in the size range of 5–20 nm, which catalyzed the in situ production of H2O2 from formic acid (FA) and oxygen. Then the in situ generated H2O2 underwent Fenton-like reactions with nontronite for CBZ degradation. With bioPd-NPs and nontronite dosage of 1 g/L and FA concentration of 20 mM, the complete CBZ (10 mg/L) degradation was achieved within 60 min. Oxidative radicals such as HO· and H2O2 generated in our constructed system played key roles in CBZ degradation. Intermediates/products identification and theoretical calculation revealed that hydroxylation was the main CBZ degradation pathway. This work provides a promising Fenton-like technology for elimination of CBZ from environment with prevention of additional H2O2 supplementation and excessive iron mud production.

Iron overload, its causes and complications

Iron overload shows bioaccumulation of iron in the cells of body due to any reason or factor in the field of biology and medicine. The underlying mechanisms and causes may vary and also the physiology and pathology. The most prominent causes of iron overload are hereditary haemochromatosis (HHC) and iron overload due to blood transfusions [1]. These two causes of iron overload can result from repeated blood transfusions. Iron overload can be prevented by regulating iron absorption in most humans. People with elevated levels of iron in the body get disorders of iron overload and iron overload in the body is the risk factor for many cancers. Iron overload happens in those persons with impaired iron absorption regulation mechanisms. Iron overload caused by transfusions causes malfunctions of the liver, heart and endocrine organs. Problems may begin after 30 units of red blood cells or even earlier [2].&#x0D; Human body has the regulatory mechanism to lessen the amount of iron that is absorbed by the cells through digested food. However, it doesnot completely ceases or blocks the iron transportation pathway, even in the circumstances, where the extra iron deteriorates the linings of intestine e.g. if children consume heavy dosage of iron tablets produced for adults, even this more quantity of iron may cause fatal syndrome of iron overload via bloodstream. Increased amounts of free iron in blood stream will damage the hepatic, cardiac and other cells which are involved in metabolic pathways. Iron overload also causes hepatocellular carcinoma [3].&#x0D; Generally iron overload is a risk factor for cancer and this hypothesis is supported and accepted by many experiments, studies and human data. An overproduction of reactive oxygen species and free radicals could explain its oncogenic effect. Among the many factors (viral hepatitis, alcohol, tobacco etc.) which play a role in carcinogenesis, iron overload is probably an important one and therefore should be diagnosed and treated well especially at their early stages treated [4].