Search Results (720)

Phosphogypsum (PG) is a byproduct of the wet phosphoric acid (WPA) production process. Since PG originates from phosphate rock (PR), it holds various concentrations of heavy metal and radionuclide, posing an environmental threat because of its large production and long-term accumulation. In addition to toxic heavy metals, PG may also be an alternative source of rare earth elements (REEs), since over 60% of REEs in PR transfer to PG during acid digestion. With the increasing demand of phosphoric acid (PA), global PG generation is approaching 300 million tons annually. Since 1994, an estimated 6.73 billion tons of PG has been produced worldwide, with approximately 58% (approx. 3.7 billion tons) ending up in stacks. Assuming a conservative REE content of 0.1%, these stacks may hold over 3.7 million tons of REEs. This review discusses phosphoric acid production processes and the transfer of REEs from PR to PG. In addition, it also discusses the current REEs world reserves, their presence in primary and secondary sources, and their uses. The review critically evaluates the research that has been conducted so far and the recent innovations in REE recovery from PG, and discusses the challenges associated with scalability and raw material variability. Full article

Titanium and its alloys are widely used in biomedical implants due to their favorable mechanical properties and corrosion resistance; however, their natural surface lacks sufficient bioactivity and antibacterial performance. Micro-arc oxidation is a promising approach to producing bioactive coatings, and the incorporation of nanoparticles such as TiO₂ may further improve their functionality. This study aimed to determine the optimal TiO₂ nanoparticle concentration in the micro-arc oxidation electrolyte that ensures coating stability and biological safety. Calcium–phosphate coatings were fabricated on commercially pure titanium using micro-arc oxidation with two TiO₂ concentrations: 0.5 wt.% (MAO 1) and 1 wt.% (MAO 2). Surface morphology, porosity, and phase composition were analyzed by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. Corrosion resistance was evaluated via potentiodynamic polarization in NaCl and Ringer’s solutions, while biocompatibility was assessed in vitro using HOS human osteosarcoma cells and MTT assays. Increasing the TiO₂ content to 1% decreased coating porosity (13.7% vs. 26.3% for MAO 1), enhanced corrosion protection, and reduced the friction coefficient compared to bare titanium. However, MAO 2 exhibited high cytotoxicity (81% cell death) and partial structural degradation in the biological medium. MAO 1 maintained integrity and showed no toxic effects (3% cell death). These results suggest that 0.5% TiO₂ is the optimal concentration, providing a balance between corrosion resistance, mechanical stability, and biocompatibility, supporting the development of safer implant coatings. Full article

Dichlorvos (DDVP) has been used in the management of agricultural pests for a long time. DDVP can cause DNA damage in mammals, and its residues in the environment and food have attracted attention. In this study, we reported a DDVP-degrading strain, Stenotrophomonas acidaminiphila G1, which could degrade DDVP to 20 mg/L with a DT₅₀ of 3.81 min at 37 °C, a pH of 7.0, and a concentration of 1.18 × 10¹⁰ colony-forming units (CFUs)/mL. Strain G1’s DDVP degradation products were determined by comparison with standard substances and UPLC-MS/MS analysis. The results showed that dimethyl phosphate (DMPP) was the main metabolite of DDVP, and its toxicity to non-target organisms was significantly lower than that of the parent compound. Furthermore, the key genes for the degradation of DDVP by strain G1 were analyzed using whole-genome sequencing. A methyl parathion hydrolase gene, mpd, was identified, and its activity was verified through prokaryotic expression and enzyme kinetics. The purified enzyme MPD could entirely degrade 20 mg/L DDVP within 1 min. These results not only provide biological resources for the rapid degradation of organophosphorus pesticides but also offer a theoretical basis for the efficient remediation of pesticide residues. Full article

Prophylactic measures and treatment strategies of implant-related bone and joint infections frequently involve the local delivery of high doses of antimicrobial drugs into the affected bone tissue or articular space in addition to the use of systemic antibiotics. Antibiotic-loaded biomaterials, such as Polymethyl Methacrylate (PMMA) cement, calcium sulfate, calcium phosphate, bioglass, and others, have proven to be clinically effective. However, they suffer from important limitations regarding elution and freedom of choice of admixable antimicrobial drugs. In order to overcome these shortcomings, the techniques of direct intraosseous or intra-articular injection/infusion of antibiotics via needles/cannulas or catheters are gaining popularity. Their attractiveness is based on the potential to achieve extremely high drug concentrations in situ, which can be maintained for as long as the catheters are left in place without increased risks of systemic toxicity. Although these methods are still in an experimental stage, reports on their clinical outcomes look promising. This articles summarizes the knowledge of when, how, and in which clinical settings the different modes and philosophies of local antibiotic delivery work best, with the aim to provide surgeons and infectious disease physicians guidance in clinical practice. This will help to optimize the use for the sake of the patients. Full article

Background/Objectives: This study developed a targeted drug delivery nanoplatform for treating HER2-positive breast cancer. The nanoplatform encapsulated two hydrophobic anticancer agents, neratinib (NTB) and docetaxel (DTX), within nanoparticles (DTX+NTB−NP) functionalized for conjugation to trastuzumab to form trastuzumab-tagged nanoparticles (TRZ−NP). Trastuzumab is a HER2-specific monoclo-nal antibody that binds to HER2 receptors, blocking signal transduction and inducing an-tibody-dependent cellular cytotoxicity (ADCC). Upon receptor-mediated endocytosis, neratinib inhibits cytosolic HER2 signaling, while docetaxel disrupts mitotic cell division, collectively leading to tumor cell death. Methods: Nanoparticles were fabricated by the nanoprecipitation technique, followed by surface modification with a crosslinker and a targeting moiety. DTX+NTB−NP, TRZ−NP, and singly loaded nanoparticles (NTB−NP and DTX−NP) were characterized and their effects evaluated in HER2-positive cancer cell line and xenograft model. Results: In vitro antiproliferation assay in SKBR-3 cell line re-veals a dose and time-dependent cytotoxicity. There was no significant difference in cyto-toxicity observed between DTX+NTB−NP and its free form (DTX+NTB) [p = 0.9172], and between TRZ−NP and its free form (TRZ+DTX+NTB) [p = 0.6750]. However, TRZ−NP, at half the concentration of the singly loaded nanoparticles, significantly reduced the viabil-ity of SKBR-3 cells compared to pure trastuzumab (TRZ) [p < 0.001], NTB−NP [p = 0.0019], and DTX−NP [p = 0.0002]. In vivo evaluation in female athymic nude mice showed sig-nificant log relative tumor volume (%) reduction in groups treated with TRZ−NP and DTX+NTB−NP compared to PBS (phosphate-buffered saline) controls (p ≤ 0.001 and p ≤ 0.001), respectively. Notably, TRZ−NP demonstrated a statistically significant regression in the log relative tumor volume (%) compared to DTX+NTB−NP (p = 0.001). Conclusions: These findings underscore the therapeutic potential and suitability of these nanoplatforms for the precise and controlled targeting of HER2-positive tumors. This study is the first to synchronize the delivery of multiple agents-docetaxel, neratinib, and trastuzumab-within a nanoparticle system for treating HER2-positive tumors, offering a promising strategy to enhance treatment outcomes for HER2 positive breast cancer patients. Full article

Efficient allocation of mineral nutrients and photoassimilates is essential for grain development in rice. However, the transcriptional programs governing nutrient transport at key reproductive stages remain largely unresolved. Here, we performed a comprehensive transcriptome analysis of rice (Oryza sativa L.) across spatial (nodes, roots, and five other tissues) and temporal (seven reproductive stages) dimensions to elucidate the molecular basis of nutrient transport and allocation. RNA-seq profiling of node I identified stage-specific gene expression patterns, with the grain filling stage marked by strong induction of transporters involved in mineral allocation (e.g., OsYSL2, OsZIP3, OsSULTR3;3, SPDT) and carbohydrate distribution (e.g., OsSWEET13, OsSWEET14, OsMST6). Comparative analysis with the neck-panicle node (NPN) and root revealed tissue-specific regulatory networks, including nitrate (OsNRT1.1A, OsNRT2.3) and phosphate (OsPHT1;4, OsPHO1;3) transporters enriched at the grain filling stage. Root expression of Cd/As-related transporters (OsNRAMP5, OsCd1, OsLsi1, OsLsi2, OsLsi3) during grain filling highlights the contribution of belowground uptake to grain metal accumulation. Together, our study establishes a spatiotemporal atlas of nutrient transporter gene activity during rice reproductive development and identifies candidate genes regulating upward and lateral nutrient allocation. These findings provide insights into improving nutrient use efficiency and reducing toxic metal accumulation in rice grains through targeted manipulation of nodal and root transport systems. Full article

Phosphorus, a crucial yet nonrenewable resource, is essential for agriculture, life processes, and various industries. In this study, we employed co-pyrolysis of eggshells and peanut shells to prepare calcium-based biochar (EPB) with a high adsorption capacity and ecological non-toxicity, enabling effective phosphorus recovery from wastewater. EPB was characterized via X-ray diffraction, scanning electron microscopy, electron probe microanalysis, and Brunauer–Emmett–Teller analysis. Additionally, its phosphate adsorption characteristics were investigated under varying temperature, pH, and coexisting ion conditions. Phosphate adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 178.08 mg/g, and the kinetics aligned with those of the quasi-second-order kinetic model. Phosphate adsorption by EPB was driven by electrostatic attraction and chemical precipitation. Moreover, we investigated the effects of phosphorus-enriched biochar on the growth and development of tobacco and soil microbial communities. Phosphorus-enriched biochar increased organic and inorganic phosphorus levels and promoted tobacco growth compared with conventional fertilizers. Phosphorus-enriched biochar reshaped tobacco rhizosphere microbial communities, promoting beneficial taxa, such as Nitrospira. Structural equation analysis showed that EPB enhanced microbial alpha diversity and key microbial communities, improving phosphorus availability and tobacco growth and development. Conclusively, this study provides a theoretical reference for phosphorus-containing wastewater treatment and reuse. Full article

Organophosphorus flame retardants (OPFRs) are emerging alternatives to halogenated compounds, yet their environmental toxicity remains underexplored. This study evaluated the developmental toxicity of two aryl-OPFRs, triphenyl phosphate (TPP) and tricresyl phosphate (TCP), in zebrafish (Danio rerio) from 2 h to 5 days post fertilization (hpf–dpf). Survival, hatching rate, and malformations were assessed across concentrations of 250–1000 µg/L, alongside with gene expression analysis at 5 dpf (250 and 500 µg/L) targeting detoxification (ces2), immune responses (il1β, casp9), and epigenetic markers (dnmt1, dnmt3). In vitro enzymatic assays evaluated interactions of both aryl-OPFRs with carboxylesterase (CE) and acetylcholinesterase (AChE) enzymes. While no significant morphological effects were observed, TPP showed higher toxicity than TCP. Notably, TCP (500 µg/L) downregulated genes linked to metabolism and immunity. CE activity and ces2 modulation may suggest CE as a potential biomarker for aryl-OPFR exposure. These findings, although at concentrations above the environmental ones, may be valuable for mechanistic purposes and underscore the need for further investigation in developmental toxicity given their lipophilic nature and distinct molecular responses. Full article

The maintenance of intracellular redox homeostasis depends on the GSH/GSSG pair, which is the primary intracellular redox buffer. However, the NADPH/NADP⁺ pair also plays a vital role in this process. The primary source of NADPH is the pentose phosphate pathway and deficiency in the enzymes responsible for NADPH production in this pathway leads to developing of alternative NADPH supply strategies. The choice of compensation strategy has several consequences for cells physiology. The present study investigates how Saccharomyces cerevisiae yeast strains defective in generating NADPH via the pentose phosphate pathway due to deletion of ZWF1, GND1, or GND2 genes, respond to redox homeostasis disruption caused by allyl alcohol, a metabolic precursor of acrolein. Acrolein is a highly reactive aldehyde that rapidly depletes glutathione and triggers oxidative stress. Therefore, cells respond to acrolein through attempts to increase glutathione synthesis, but also by increasing NADPH production. The response requires coordinated action of glutathione- and NADPH-dependent systems. The high sensitivity of the Δgnd1 strain, which is unable to activate an adequate stress response, is evidence of this. The strategy employed by this strain to maintain redox homeostasis is inadequate and may even exacerbate allyl alcohol toxicity. Full article

Plant growth-promoting rhizobacteria (PGPR) employ various mechanisms to enhance plant development and growth as well as to mitigate environmental stress, including heavy metal contamination. Cadmium is a particularly severe stressor, toxic to both plants and soil microbiota. Mesembryanthemum crystallinum L. (the common ice plant), a fast-growing semi-halophyte, was previously investigated for phytoremediation potential towards saline environments and toxic metals, especially cadmium and chromium. The study was aimed at assessing whether bacteria isolated from the rhizosphere of M. crystallinum treated with Cd reveal growth-promoting traits and if the plant tolerance to Cd results from a synergistic action of the Cd/salt-resistant strains. The isolates demonstrated PGP characteristics, including nitrogen fixation, phosphate solubilization, and production of ammonia, indolyl-3-acetic acid (IAA), and siderophores. A microbial consortium consisting of these strains was developed and applied to pots with M. crystallinum. After a 14-day experiment, plant growth and Cd-accumulation potential were evaluated upon treatment with 1 mM or 10 mM Cd, either in the presence or absence of NaCl. Plant inoculation with the consortium stimulated Cd accumulation both by roots and shoots at 10 mM Cd under saline conditions. The results suggest that bioaugmentation of M. crystallinum with the bacterial community can be used as an effective, sustainable phytoremediation method for cadmium-contaminated soils. Full article

Calcium phosphate (CaP) materials are biocompatible and non-toxic to the body. However, they lack biointegration, exhibit a low resorption rate and can cause fibrous encapsulation throughout the implant material. A promising approach for dental or orthopedic regeneration is the use of dicalcium phosphate dihydrate (DCPD) and octacalcium phosphate (OCP), as they are well-suited to bone components. From a novel perspective, these apatites can be used as drug carriers for individuals with low tolerance to common excipients. In this study, the transformation of DCPD into different morphologies in DMEM was investigated using an induced dissolution and reprecipitation reaction solution. The DCPD transformation time was observed to be morphology-dependent and can occur between 48 and 168 h. In the interaction with simulated body fluid (SBF), simulated gastric fluid (SGF) and a combination of both (BFS/SGF), a higher mass loss was observed in SGF (~80%) than in the other fluids (~35%). The structural changes presented in DCPD and OCP before and after immersion in physiological fluids were analyzed by ATR-FTIR, SEM, XRD and EDS. The obtained OCP showed low stability in SGF compared to SBF and SBF/SGF, which indicates that it may be a suitable candidate for drug delivery in the digestive tract. Full article

Polyhexamethylene guanidine phosphate (PHMG-p), a widely used disinfectant component in household humidifiers, has been implicated in various health issues, including pulmonary toxicity. Many people use humidifiers to improve dry eye disease (DED). The current study was performed to elucidate the effect of PHMG-p on eye dryness in a rat model using metabolomics. Male Sprague Dawley rats were exposed to PHMG-p (0.1% and 0.3%) following a previously established DED induction model using scopolamine hydrobromide and desiccation stress. Ocular surface damage was assessed using corneal fluorescein staining, tear volume measurement, and tear break-up time (TBUT). Plasma and urine samples were analyzed using ¹H-NMR-based metabolomics to identify metabolic alterations associated with PHMG-P-p exposure and DED pathogenesis. PHMG-p exposure exacerbated DED symptoms, as evidenced by a significant reduction in tear volume, shorter TBUT, and increased corneal damage compared to the control group. Metabolomic profiling identified distinct metabolic changes in PHMG-p-exposed groups, including alterations in glutamate, glycine, citrate, and succinate metabolism. These metabolic changes correlated with increased levels of inflammatory cytokines such as IL-1β, IL-6, and TNF-α in the corneal and lacrimal gland tissues. Our findings suggest that PHMG-p exposure contributes to DED pathophysiology by inducing metabolic disturbances and inflammatory responses in the ocular surface. This study highlights the need for further investigation into the potential risks of PHMG-p exposure on ocular health and provides novel insights into the metabolic underpinnings of DED. Full article

Hair loss (alopecia) is a common disorder caused by an interruption in the body’s cycle of hair production. This pathology negatively affects the psychoemotional state of patients and significantly reduces their quality of life. The currently available medical treatments (including minoxidil therapy) are effective in arresting the progression of the disease; however, they allow only partial regrowth of hair at best. A significant clinical result occurs only with regular drug use. There is still great interest in finding new drugs for the treatment of alopecia. In this study, we aimed to examine the effect of an aqueous dispersion of unmodified fullerene C60 (ADF) on hair growth. ADF, produced by a unique technology, is biocompatible and non-toxic. Nu/nu mice were subcutaneously injected (2 μg/animal) every two days for a period of 11 days with ADF and, for control purposes, with phosphate-buffered saline (PBS). It was shown that ADF stimulated hair growth. Histological analysis of the nu/nu mice skin areas showed that animals treated with ADF had significantly more (about twice as many) hair follicles in the anagen phase compared to mice treated with PBS. The effect on hair growth persisted even after discontinuation of ADF administration. Analysis of gene expression demonstrated that ADF affected the Wnt-signaling pathway, increased the expression of the Wnt10b (wingless-type Mouse Mammary Tumor Virus integration site family, member 10B) factor, angiogenetic factors, and downregulated tumor necrosis factor-alpha levels. We propose that the mechanism of ADF action is likely related to its ability to attract macrophages to the hair follicle microenvironment and promote their polarization to the M2 phenotype. In addition, using molecular modeling, we tried to substantiate our hypothesis about the interaction of ADF with the adenosine A2A receptor, which may cause a decrease in tumor necrosis factor-alpha production. Thus, ADF may become a promising drug for the development of new approaches to the treatment of alopecia associated with immune disorders. Full article

The lipooligosaccharide (LOS) of the marine bacterium Kangiella japonica KMM 3897 was structurally characterized using chemical analysis, NMR spectroscopy, and MALDI-TOF mass spectrometry. The oligosaccharide core consists of a monophosphorylated trisaccharide containing 2-amino-2-deoxy-D-glucose, D-glycero-D-manno-heptose, and 3-deoxy-D-manno-oct-2-ulosonic acid. The penta-acylated lipid A moiety features a glucosamine disaccharide backbone with phosphate groups and amide- and ester-linked primary fatty acids [i11:0 (3-OH)], along with a secondary acyl chain (i11:0 or 11:0). Immunostimulatory assays revealed that K. japonica KMM 3897 LOS induced significantly weaker cytokine production in human peripheral blood mononuclear cells (PBMCs) compared with E. coli LPS. Notably, it exhibited potent antagonistic activity against E. coli LPS-mediated toxicity and suppressed caspase-4 activation in LPS-treated PBMCs. These findings highlight its anti-inflammatory and protective properties. Full article

The treatment of organic phosphate ester (OPE) pollutants in water is a challenging but highly necessary task. In this study, an advanced oxidation process through light activation of peroxymonosulfate (PMS) involving graphene oxide (GO) as a promoter was developed to degrade OPE in water, taking triphenyl phosphate (TPhP) as an example. The developed “Light+PMS+GO” system demonstrated good convenience, high TPhP degradation efficiency, tolerance in a near-neutral pH, satisfactory re-usability, and a low toxicity risk of degradation products. Under the investigated reaction conditions, viz., the full spectrum of a 300 W Xe lamp, PMS of 200 mg L⁻¹, GO of 4 mg L⁻¹, and TPhP of 10 μmol L⁻¹, the “Light+PMS+GO” system achieved nearly 100% TPhP degradation efficiency during a 15 min reaction duration with a 5.81-fold enhancement in the reaction rate constant, compared with the control group without GO. Through quenching experiments and electron paramagnetic resonance studies, singlet oxygen was identified as the main reactive species for TPhP degradation. Further studies implied that GO could accumulate both oxidants and pollutants on the surface, providing additional reaction sites for PMS activation and accelerating electron transfer, which all contributed to the enhancement of TPhP degradation. Finally, the TPhP degradation pathway was proposed and a preliminary toxicity evaluation of degradation intermediates was conducted. The convenience, high removal efficiency, and good re-usability indicates that the developed “Light+PMS+GO” reaction system has great potential for future applications. Full article