Increase In Ion Concentration Research Articles

Effect of Magnesium and Ferric Ions on the Biomineralization of Calcium Carbonate Induced by Synechocystis sp. PCC 6803

The discovery of cyanobacteria fossils in microbialite prompts the investigation of carbonate biomineralization using cyanobacteria. However, the impact of coexisting magnesium and iron in microbialite on carbonate biomineralization has been overlooked. Here, Synechocystis sp. PCC 6803 was used to induce calcium carbonate in the presence of coexisting magnesium and ferric ions. The findings demonstrate that cell concentration, pH, carbonic anhydrase activity, and carbonate and bicarbonate concentrations decreased with increasing concentrations of magnesium and calcium ions. Ferric ions yielded a contrasting effect. The levels of deoxyribonucleic acid, protein, polysaccharides, and humic substances in extracellular polymeric substances increased in the presence of separated or coexisting calcium, magnesium, and ferric ions. Magnesium ions inhibited calcium ion precipitation, whereas ferric ions exhibited the opposite effect. Protein secondary structures became more abundant and O-C=O and N-C=O contents increased with increasing ion concentrations by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. Scanning electron microscopy revealed that ferric ions lead to rougher surfaces and incomplete rhombohedral structures of calcite, whereas magnesium ions promoted greater diversity in morphology. Magnesium ions enhanced the incorporation of ferric ions. This work aims to further understand the effect of magnesium and ferric ions on calcium carbonate biomineralization induced by cyanobacteria.

GC/MS Analysis and a 30-day Toxicological Evaluation of a Nigerian Immunomodulatory Polyherbal Supplement (PHS)

Background and Purpose: A Nigerian-formulated polyherbal supplement (PHS) is consumed for its folkloric claims of boosting the immune system. The aim of this study was to toxicologically evaluate a 30-day administration of PHS.
 Methods: Gas Chromatography/Mass Spectrometry (GC/MS) analysis was carried out on the ethanol extract of PHS. Thirty-two Wistar rats were randomly assigned to four groups. One group served as control while the other three groups were administered 250, 500, and 1000 mg/kg/day of PHS for 30 consecutive days. The animals were anesthetized, and cardiac puncture was used to obtain whole blood for hematology and serum biochemistry. In vivo, antioxidant assays were also carried out on the liver homogenates. The liver, kidneys, and heart were examined histologically.
 Results: The most abundant compounds identified were eucalyptol, alpha-pinene, and phytol. There were no adverse hematological effects. Total cholesterol, LDL-C, and catalase were reduced significantly (P<0.05). At 1000 mg/kg/day, there was a significant increase in creatinine, sodium ion, and glutathione peroxidase concentration. The histological examination of the heart, kidneys, and liver revealed that PHS did not cause any major tissue lesions at 250 and 500 mg/kg/day. Tissue lesions and pathologies were obvious at 1000 mg/kg/day.
 Conclusion: The polyherbal supplement seems to be relatively safe if used at doses up to 250 mg/kg/day. Higher doses may cause renal and hepatic lesions.

Harvesting of aerial humidity with natural hygroscopic salt excretions.

Plants and animals that thrive in arid regions utilize the diurnal changes in environmental temperature and humidity to optimize their water budget by combining water-harvesting mechanisms and morphophysiological traits. The Athel tamarisk (Tamarix aphylla) is a halophytic desert shrub that survives in arid, hypersaline conditions by excreting concentrated solutions of ions as droplets on its surface that crystallize into salt crystals and fall off the branches. Here, we describe the crystallization on the surface of the plant and explore the effects of external conditions such as diurnal changes in humidity and temperature. The salt mixtures contain at least ten common minerals, with NaCl and CaSO4·2H2O being the major products, SiO2 and CaCO3 main sand contaminants, and Li2SO4, CaSO4, KCl, K2Ca(SO4)2·H2O, CaMg(CO3)2 and AlNaSi3O8 present in smaller amounts. In natural conditions, the hanging or sitting droplets remain firmly attached to the surface, with an average adhesion force of 275 ± 3.5 µN measured for pure water. Rather than using morphological features of the surface, the droplets adhere by chemical interactions, predominantly by hydrogen bonding. Increasing ion concentration slightly increases the contact angle on the hydrophobic cuticle, thereby lowering surface wettability. Small amounts of lithium sulfate and possibly other hygroscopic salts result in strong hygroscopicity and propensity for deliquescence of the salt mixture overnight. Within a broader context, this natural mechanism for humidity harvesting that uses environmentally benign salts as moisture adsorbents could provide a bioinspired approach that complements the currently available water collection or cloud-seeding technologies.

Electron paramagnetic resonance and luminescence properties of Eu2+ in oxyfluoride barium borate glasses

The Eu-doped xBaO-(100-x)B2O3 and xBaF2-(100-x)B2O3 glasses were prepared by melting method under a reducing atmosphere, exhibiting broadband luminescence peaks of 4f65 d1→4f7 in the excitation range of 300–400 nm. PL, EPR, and XPS were used to analyze the effects of the Ba2+, F−, and Eu ion content on the Eu2+/Eu3+ ratio and Eu2+ emission wavelength and intensity. An excess of Ba2+ ions with a high optical basicity reduced the Eu2+/Eu3+ ratio and enhanced the ligand field strength surrounding the Eu2+ ions, decreasing the Eu2+ luminescence intensity and red-shifting the luminescence peak. The addition of F− had the effect of diminishing the optical basicity, decreasing the OH groups content and eliminating Eu2+ clusters, which not only mitigated the effects of the Ba2+ ions, but also significantly enhanced the luminescence intensity of Eu2+ ions. An increase in the Eu ion concentration led to a red-shift in the Eu2+ fluorescence, which was attributed to the nephelauxetic effect. Therefore, the luminescence color of these glass samples could be manipulated by adjusting the doping concentrations of Ba2+, F−, and Eu2+.

Biomass derived green carbon dots for sensing applications of effective detection of metallic contaminants in the environment

The rapid consumption of metals and unorganized disposal have led to unprecedented increases in heavy metal ion concentrations in the ecosystem, which disrupts environmental homeostasis and results in agricultural biodiversity loss. Mitigation and remediation plans for heavy metal pollution are largely dependent on the discovery of cost-effective, biocompatible, specific, and robust detectors because conventional methods involve sophisticated electronics and sample preparation procedures. Carbon dots (CDs) have gained significant importance in sensing applications related to environmental sustainability. Fluorescence sensor applications have been enhanced by their distinctive spectral properties and the potential for developing efficient photonic devices. With the recent development of biomass-functionalized carbon dots, a wide spectrum of multivalent and bivalent transition metal ions responsible for water quality degradation can be detected with high efficiency and minimal toxicity. This review explores the various methods of manufacturing carbon dots and the biochemical mechanisms involved in metal detection using green carbon dots for sensing applications involving Cu (II), Fe (III), Hg (II), and Cr (VI) ions in aqueous systems. A detailed discussion of practical challenges and future recommendations is presented to identify feasible design routes.

Difference in the Osteoblastic Calcium Signaling Response Between Compression and Stretching Mechanical Stimuli

In orthodontics, various forms of mechanical stimulation induce opposing bone metabolism mechanisms. Bone resorption and bone formation occur in areas of compressive and tensile force action, respectively. The mechanism that causes such a difference in bone metabolism is still unclear. In this study, we investigated the difference in the osteoblastic calcium signaling response between compression and stretching mechanical stimuli. We applied two types of mechanical stimuli to osteoblast-like MC3T3-E1 cells: first microneedle direct indentation onto the cell as compression stimuli, and second stretching stimuli by using originally developed cell stretching MEMS device. Cells were treated with thapsigargin and calcium-free medium to investigate the source of the calcium ion. The results demonstrated variations in the osteoblastic calcium signaling response between the compression and stretching stimuli. The magnitude of an increase in the intracellular calcium ion concentration is much higher in the compression stimuli-applied cell group. Treatment of calcium-free medium nearly suppressed the calcium signaling response to both types of mechanical stimulation. Thapsigargin treatment induced an increase in the magnitude of calcium signaling response to the compression stimuli, while suppressed the slow and sustained increase in the calcium ion concentration in the stretching stimuli-applied cell group. These findings demonstrate the difference in the characteristics of osteoblastic calcium signaling response between compression and stretching mechanical stimuli.

Adsorption of tetracycline on polyvinyl chloride microplastics in aqueous environments

Microplastics (MPs), as carriers of organic pollutants in the environment, have become a growing public concern in recent years. Tetracycline (TTC) is an antibiotic that can be absorbed by MPs and have a harmful effect on human health. Therefore, this study was conducted with the aim of investigating the adsorption rate of TTC onto polyvinyl chloride (PVC) MPs. In addition, the adsorption mechanism of this process was studied using isothermal, kinetic, and thermodynamic models. For this purpose, experimental runs using the Box-Behnken model were designed to investigate the main research parameters, including PVC dose (0.5–2 g/L), reaction time (5–55 min), initial antibiotic concentration (5–15 mg/L), and pH (4–10). Based on the research findings, the highest TTC adsorption rate (93.23%) was obtained at a pH of 10, a contact time of 55 min, an adsorbent dose of 1.25 g/L, and an antibiotic concentration of 10 mg/L. The study found that the adsorption rate of TTC followed the pseudo-second-order and Langmuir models. Thermodynamic data indicated that the process was spontaneous, exothermic, and physical. Increasing ion concentration decreased TTC adsorption, and distilled water had the highest adsorption, while municipal wastewater had the lowest adsorption. These findings provide valuable insights into the behavior of MPs and organic pollutants, underscoring the importance of conducting additional research and implementing measures to mitigate their detrimental effects on human health and the environment.

Colorimetric and absorbance based sensor for sulfide and bicarbonate ions by dye doped polymer composite

We have developed a simple, rapid and cost-effective Dual-channel “colorimetric and absorbance” sensor using polyvinylpyrrolidone (PVP) capped Rhodamine6g (Rh6G) dye composite. Dye-doped polymer composite probe (PVPRH) exhibit intense, narrow absorption properties and long-term stability than the bare Rh6G. The probe’s colorimetric relationship with pH was demonstrated by absorption titration. The PVPRH provides a sensitive dual channel method for the determination of sulfide and bicarbonate with colorimetric response and absorption quenching. The synthesized probe, as a two-faced, exhibited remarkable colorimetric responses from orange to pale yellow in the presence of S2- and orange to soft pink in the presence of HCO3- ion, which can be observed by the naked eye also. Under optimal conditions, the relative absorption intensity decreases with increasing ion concentration of sulfide and bicarbonate ions. This trend is observed within the probe solution concentration range of 5 mM to 50 mM. The Dye-doped polymer composite probe is easy, cost effective, rapid, and has real time detection capability for sulfide and bicarbonate ions. The composite probe is stable and optically modified and can be successfully used for detections of S2- and HCO3- ions as strip senor.

Exploration of simple and economic D-π-A- chalcone in selective Fe3+ metal sensing via PET quenching effect in water as a medium and mechanistic study using DFT calculations

Chalcone with high conjugation is a key structural motif in biologically active molecules and has found utility as a dye. These molecular frameworks provide coordination sites for metal ions, attracting scientific interest worldwide. Chalcone (3g) was synthesized using the Claisen–Schmidt condensation as a good donor-pi-acceptor system (D-π-A), that showed intramolecular charge transfer (ICT). Chalcone 3g was soluble in water and showed maxima in UV visible and fluorescence emission spectra, and it also exhibited a broad-spectrum peak at 572 nm. Chalcone 3g showed the detection of different metal ions like Li+, Na+, K+, Mg2+, Cu2+, Zn2+, Fe3+, and Al3+ions in UV–visible and fluorescence spectroscopy while able to specific detection of Fe3+ ions at 572 nm among all other metals with high sensing properties and detection limit. An increase in the metal ion concentration gradually quenched the absorption of chalcone 3g due to the restriction in internal charge transfer. We performed Job's plot to obtain the stoichiometry of chalcone 3g with Fe3+ metal, which was observed to be a 1:1 ratio (LOD and LOQ). A study of chalcone 3g coated filter paper strip was performed, which helped detect Fe3+ ions with reduced colour intensity. Chalcone 3g and metal complexes were calculated theoretically using a Density Functional Theory (DFT) with the B3LYP module of the DMol3. This study suggested that the complexation of 3g and Fe3+ found stable. Herein, we are reporting a simpler chalcone for selective metal ions detection with low LOD and LOQ, which can be helpful in the further development of an easy and convenient metal-sensing fluorescent probe.

Confined assembly of size-tunable silver nanoprisms on flexible Teflon tapes as highly active SERS hotspots for ultralow-level sensing of DNA and glucose

The design of smart and advanced sensors facilitates highly sensitive optical detection platforms for biomolecules. Herein, we attempted the confined assembly of silver nanoprisms (SNPs) on hydrophobic Teflon tapes to design a highly flexible and ultrasensitive biosensing platform for DNA and glucose. We investigated the sensor characteristics including morphological, optical, and SERS activities as a function of nanoparticle size. Pyramidal SNPs were synthesized, whose size was tuned by varying the bromide ion concentrations. The size of SNPs was decreased with an increase in bromide ion concentrations, where quasi-spherical nanoparticles were formed at higher bromide content. The hydrophobic Teflon surface caused considerable constrain during the evaporation of nanoparticle suspension, leading to highly confined SNPs. SERS activities of Teflon/SNP sensors were tuned by varying the size of SNPs, where a size of ∼34 nm exhibited the highest signal enhancement. The optimum Teflon/SNP sensor showed an enhancement factor of 1.3 × 109 with high stability and excellent reproducibility. Teflon/SNP sensor was further exploited to detect DNA and glucose in a label-free method, exhibiting sensitivities of approximately 13.6 fg/µL and 5 µM, respectively. Real-time monitoring of DNA and glucose from saliva was also investigated. Teflon/SNP substrates were found to be excellent biosensing platforms for ultralow-level sensing of biomolecules in a rapid and cost-effective manner.

Quantitative Evaluation of the Effects of Salt Concentration and pH on the Self-Assembly of Kaolin Nanoplatelets.

Diffusion of pollutants in the earth's strata threatens both the environment and human health. The clay soil microstructure that plays a crucial role in the diffusion of pollutants is significantly influenced by the pore water chemistry. However, there is still a lack of quantitative evaluation of pore water chemistry on clay fabric evolution. To bring new insights, we systematically examined the impact of water chemistry (mainly refers to salt ion concentration and pH) on the self-assembly form (fabric) of kaolin platelets and evaluated the fabric quantitatively. The results show that as the salt ion concentration increases, the "kaolin book" structure is formed, which can be captured by the (001) and (020) pole figures. Under acidic conditions, kaolin platelets turn randomly arranged; however, with the increase of pH, the edge-to-face (EF) microstructure of kaolin platelets gradually changes to a face-to-face (FF) structure. Under alkali-eq conditions, kaolin platelets form a dispersion assembly dominated by FF repulsion. However, the strong alkaline condition triggers the decomposition of kaolin, leading to a notable decrease in the maximum pole density. The conclusions were substantiated through insightful AFM tests. Moreover, we addressed the advantages and limitations of 1DXRD and 2DXRD by analyzing the trend between the OI and pole density, with 2DXRD being favored for its accuracy. Overall, this study provides insights into clay platelets and the self-assembly of kaolin under different water chemistry conditions, which have significant implications for predicting and modeling the physical properties of clay under special environmental conditions.

Sensing the impact of diet composition on protein fermentation by direct electrochemical NH4+ sensing in gastrointestinal digesta

The correlation between nutritional habits and gut health directly impacts the gut-brain axis via a complex and not yet fully disclosed communication network. Establishing a link between our food intake and specific physiological responses as well as a better knowledge of diseases and the gut microbiota involves solving a challenging puzzle of biochemical pathways. Our understanding is limited by the inaccessibility of the gastrointestinal region to routine non-invasive chemical analysis. Here, we move a step further toward the direct assessment of a protein fermentation product, i.e., ammonium ions, via Ion Selective Electrodes (ISEs) in gastrointestinal digesta samples. By modulating the digestible protein content of the diet regimes of two groups of pigs, we discriminate the level of protein fermentation with a straightforward quasi-invivo detection method which does not require any sample preparation. Our results show more than a 2-fold increase in ammonium ion concentration (from 180 ppm to 400 ppm) in the proximal colon for a diet based on poorly digestible proteins compared with a diet based on easily digestible proteins. Our approach shows good correlation with a standard laboratory technique for the determination of NH4+, i.e., the Indophenol Blue Method. Our results show the direct sensing of a protein fermentation product in a real matrix and demonstrate the great potential of potentiometric sensors to assess ammonium concentration profiles along the gastrointestinal tract for diets varying in protein digestibility and fermentation.

What controls the hydrochemical compositions of mountainous river water in a glacierized catchment?

AbstractChemical weathering processes has become a growing issue in research on carbon cycling, however, mineral weathering by sulfuric acid and carbonic acid and its possible impacts on carbon cycle are yet unknown over the typical glacial catchment. To investigate the mechanisms of mineral weathering processes and its influence, the spatial–temporal variations of the major ions in Mingyong River, a glacier‐originated river located on the southeastern edge of the Qinghai‐Tibetan Plateau, were investigated. The seasonal and spatial variations in river solutes were resulted from the hydrological conditions and different mineral weathering rates. The results showed that the major ion compositions of the river waters were characterized by the dominance of Ca2+, Mg2+, HCO3−, with a significantly rich in SO42−. A systematic increase in ionic concentrations (apart from NH4+ and NO3−) was observed in the river water from non‐monsoon to monsoon season as well as from upstream to downstream. Piper diagram results showed 100% (upstream‐midstream) and 72.5% (downstream) contributions to Ca‐HCO3 type, respectively, indicating that a dominated carbonate weathering to the river chemistry. The (Ca2++Mg2+)/HCO3− against (SO42−/HCO3−) scatter suggested that sulfuric and carbonic acid are responsible for chemical weathering. An increased contributions of sulfuric acid from upstream (43%) to downstream (87.3%) on the (Ca2++Mg2+) and from upstream (29.6%) to downstream (88.3%) on HCO3− using the stoichiometry analysis during the monsoon season. Contrarily, H2SO4‐related dissolution (>65%) processes controlled the carbonate weathering during the non‐monsoon season, which indicated that sulfuric acid played a significant part in the process of rock dissolution that intensifies weathering. The effects of accelerated weathering on drinking and irrigation suitability suggested that the Mingyong River water is subject to a salinity hazard. This research demonstrates that the weathering of catchments involving sulfuric acid has the potential to alter carbon cycle and should be considered in global carbon cycle models.

Investigation on pitting corrosion mechanism of the Fe-based amorphous alloy coating by three-dimensional X-ray imaging at micro-scale

Few work have been performed regarding the quantitative characterization of three-dimensional (3D) pitting corrosion process directly, although the corrosion behaviors and the passivation film stability of metals in various solutions have been studied heavily. The reported work quantitatively characterized the 3D pitting corrosion of the Fe-based amorphous alloy coating (Fe-based AAC) via X-ray micro-computed tomography (X-ray micro-CT) and further elucidated the mechanism of its pitting corrosion. Moreover, the microstructure and electrochemical performance of the Fe-based AAC have also been explored. The results showed that the targeted thermal sprayed Fe43Cr20Mo10W4C15B6Y2 coating was prone to be corroded with the increase of the hydrogen ion concentration, i.e. higher hydrogen ion concentration leads to poorer corrosion performance of the Fe-based AAC. The X-ray micro-CT results revealed that the pits in the Fe-based AAC initially nucleated below the pitting potential, and they also generated in the over-passivation stage. Furthermore, it was found that the corrosive medium does not penetrate into the coating/substrate interface, and the deduced corrosion mechanism from the findings was also discussed.

Drivers of Surface Ocean Acidity Extremes in an Earth System Model

AbstractOceanic uptake of anthropogenic carbon causes acidification, a process that describes the increase in hydrogen ion concentrations ([H+]) and decrease in calcium carbonate mineral saturation states (Ω). Of particular concern are ocean acidity extreme (OAX) events, which pose a significant threat to many calcifying marine organisms. However, the mechanisms driving such extreme events are not well understood. Here, we use high‐frequency output from a fully coupled Earth system model of all processes that influence the surface ocean temperature and carbon budgets and ultimately [H+] and Ω anomalies to quantify the driving mechanisms of the onset and decline of high [H+] and low Ω extreme events. We show that enhanced temperature plays a crucial role in driving [H+] extremes, with increased net ocean heat uptake being the dominant driver of the event onset in the subtropics. In the mid‐to‐high latitudes, decreased downward vertical diffusion and mixing of warm surface waters during summer, and increased vertical mixing with warm and carbon‐rich subsurface waters during winter are the main drivers of high [H+] extreme event onset. In the tropics, increases in vertical advection of carbon‐rich subsurface waters are the primary driver of the onset of high [H+] extremes. In contrast, low Ω extremes are driven in most regions by increases in surface carbon concentration due to increased vertical mixing with carbon‐rich subsurface waters. Our study highlights the complex interplay between heat and carbon anomalies driving OAX events and provides a first foundation for more accurate prediction of their future evolution.

Removal of malachite green dye by sodium dodecyl sulfate modified bentonite clay: Kinetics, thermodynamics and isotherm modeling

Adsorption of malachite green (MG) onto sodium dodecyl sulfate (SDS) modified bentonite clay (MBC) was investigated. MBC was synthesized and characterized by X-ray diffraction (XRD), thermos-gravimetric analysis (TGA), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) Sorptometer. According to XRD analysis, the interlayer distance d-spacing increases from 1.2496 nm to 1.4000 nm after modification of bentonite clay (BC). TGA analysis suggests that the residual mass at 1198.4 °C is 92.74% which indicates that the MBC adsorbent is thermodynamically stable. BET analysis confirms that surface area decreases from 22.87 m2/g to 20.13 m2/g after modification. TEM, EDS and XPS analysis confirm the adsorption of MG onto MBC. The efficiency of this adsorbent for the uptake of MG was investigated using batch adsorption technique at various contact times, pHs, dye concentration, temperature, particle size, concentration of competitive ion and adsorbent dosage. Adsorption capacity rises as contact time, starting dye concentration and temperature increase, while decreasing when the particle size and competing ion concentration increase. The adsorption process follows the pseudo second order kinetics model over the pseudo first order kinetics model and the Elovich kinetics model. Compared to the Freundlich, Temkin and Dubinin–Radushkevich isotherm models, the Langmuir isotherm model provides greater insight into the adsorption process. The maximum adsorption capacity, qm was 1988.387 mg/g at optimum conditions (45 °C, pH 10, contact time 180 min, adsorbent dosage 200 mg/L) which was calculated from the Langmuir isotherm model. Negative values of free energy change, ΔG (−2.8464 kJ/mol at 30 °C) indicated spontaneity of the adsorption of MG onto MBC and The process is endothermic, as suggested by positive values of the heat of adsorption, ΔH (5.6514 kJ/mol). The value of activation energy (Ea = 9.7956 KJ/mol) and the estimated average free energy of adsorption (E < 8) supported that the adsorption process is physisorption.

Revealing Local Structure and Dynamics in Li-Salt Electrolytes Using Dielectric Relaxation Spectroscopy

Understanding the interplay between local structure and dynamics is critical for establishing design rules for advanced ion-conducting electrolytes. In this work, a set of Li-salt in liquid electrolytes is studied using dielectric relaxation spectroscopy (DRS) to examine correlations between several electrolyte properties, including conductivity, dielectric relaxation time and strength, ionicity, and viscosity. These properties were evaluated by changing ion concentration, solvent type, and anion type. DRS was used to identify relaxation processes associated with the solvent and different ion-solvent coordinating structures, and the dielectric properties are reported for the first time for a majority of these systems. The behavior of viscosity and conductivity were shown to change similarly with concentration when accounting for the local coordinating environment, regardless of the salt or solvent type. τα, the dielectric relaxation time of the solvent-ion complexes, is shown to be independent of ion content at low salt concentrations, when solvent separated ion pairs are the dominant ion-solvent complex. However, at high ion concentrations, a new relationship, a power-law dependence, was identified between molar conductivity and τα, as well as viscosity and τα, demonstrating that the dependence of molar conductivity or viscosity on τα is controlled in part by the solvent type, due to variation in shielding between contact ion pairs and aggregates. In contrast, there was not a clear change in the dependence of molar conductivity or viscosity on τα with changing anion. Furthermore, the effective dipole moments of the ion-solvent complexes were determined, and found to decrease with increasing ion concentration, as contact ion pairs and aggregates form. This systematic analysis of the wide range of Li-salts and solvents, and discussion of relations between different local structures and dynamic processes that contribute to conductivity, helps lay a foundation for the design of new liquid electrolytes.

Modified-Hydroxyapatite-Chitosan Hybrid Composite Interfacial Coating on 3D Polymeric Scaffolds for Bone Tissue Engineering.

Three dimensional (3D) scaffolds have huge limitations due to their low porosity, mechanical strength, and lack of direct cell-bioactive drug contact. Whereas bisphosphonate drug has the ability to stimulate osteogenesis in osteoblasts and bone marrow mesenchymal stem cells (hMSC) which attracted its therapeutic use. However it is hard administration low bioavailability, and lack of site-specificity, limiting its usage. The proposed scaffold architecture allows cells to access the bioactive surface at their apex by interacting at the scaffold's interfacial layer. The interface of 3D polycaprolactone (PCL) scaffolds has been coated with alendronate-modified hydroxyapatite (MALD) enclosed in a chitosan matrix, to mimic the native environment and stupulate the through interaction of cells to bioactive layer. Where the mechanical strength will be provided by the skeleton of PCL. In the MALD composite's hydroxyapatite (HAP) component will govern alendronate (ALD) release behavior, and HAP presence will drive the increase in local calcium ion concentration increases hMSC proliferation and differentiation. In results, MALD show release of 86.28±0.22. XPS and SEM investigation of the scaffold structure, shows inspiring particle deposition with chitosan over the interface. All scaffolds enhanced cell adhesion, proliferation, and osteocyte differentiation for over a week without in vitro cell toxicity with 3.03±0.2kPa mechanical strength.

PH-Responsive Zinc Ion Regulating Immunomodulatory Nanoparticles for Effective Cancer Immunotherapy.

Herein, we introduce a novel approach involving the utilization of a human serum albumin-coated zeolite imidazolate framework-8 containing a photosensitizer (HPZ) that exhibits targeted recognition of the tumor microenvironment, enabling the rapid elevation of zinc ion concentrations while facilitating the controlled release of an encapsulated photosensitizer (PS). At a physiological pH of 7.4, HPZ demonstrates a size of approximately 170 nm, significantly decreasing to less than 10 nm under pH 6.5 acidic conditions. Acid-induced decomposition of HPZ triggers a rapid increase in zinc ion concentration, eliciting potent cytotoxic effects against colorectal, breast, and pancreatic cancers. Additionally, upon laser irradiation, the encapsulated PS within HPZ initiates the generation of reactive oxygen species, synergistically augmenting the cytotoxicity induced by zinc ions. Intravenous administration of HPZ in a CT26 tumor-bearing mouse model resulted in a notable expansion of CD3+CD4+ helper T cells and CD3+CD8+ cytotoxic T cells, accompanied by a reduction in the CD4+CD25+Foxp3+ regulatory T-cell population. These changes led to significant inhibition of tumor growth, highlighting the efficacy of HPZ in this experimental model. Importantly, HPZ exhibits favorable safety characteristics, displaying no toxicity toward vital organs and inducing no weight loss. Thus, HPZ holds immense promise as a standalone treatment or in combination with diverse anticancer immunotherapies, underscoring its potential in the field of anticancer immunotherapy.

Effects of saline water with different concentrations of calcium and magnesium ions on emitter clogging in drip irrigation integrated water–fertilizer system

AbstractThe application of saline water in drip irrigation is severely constrained due to its high salt content, which causes precipitation and emitter clogging. Therefore, the effects of calcium and magnesium ions at 100, 150 and 200 mg/L in saline water coupled with humic acid nitrogen fertilizer on emitter clogging were studied. Compared with ground saline water, all treatments significantly increased the emitter clogging risk. In the calcium and magnesium ion treatment groups, clogging fouling increased by 23.94–58.35 and 14.55–51.21 mg/cm2, the discharge variation ratio (Dra) decreased by 22%–59% and 14%–49%, and the Christiansen coefficient of uniformity (CU) decreased by 29%–79% and 15%–74%, respectively. Higher ion concentrations caused more clogging. Saline water with a high calcium content caused more clogging. Under similar concentration conditions, the Dra and CU in high magnesium saline water were 9%–32% and 8%–51% higher, respectively. In addition, the increase in magnesium ion concentration changed the crystal form of carbonate, slowed the formation rate of precipitated dirt and significantly reduced the carbonate content by 19%–40%. Our results provide support for the popularization of saline water drip irrigation systems.