Fast Degradation Research Articles

Photodegradation of bisphenol A (BPA) in coastal aquaculture waters: Influencing factors, products, and pathways

Bisphenol A (BPA), an endocrine-disrupting contaminant, is ubiquitous in the environment due to its presence in plastics, wastewater, and agricultural runoff. This study investigated the photodegradation behavior of BPA in coastal aquaculture waters near Qingdao, China. Lower salinity promoted BPA photodegradation, while higher salinity has an inhibitory effect, suggesting slower degradation in seawater compared to ultrapure water. Triplet-excited dissolved organic matter (3DOM*) was identified as the primary mediator of BPA degradation, with additional contributions from hydroxyl radicals (•OH), singlet oxygen (1O2), and halogen radicals (HRS). Alepocephalidae aquaculture water exhibited the fastest degradation rate, likely due to its high DOM and nitrate/nitrite (NO3−/NO2−) content, which are sources of 3DOM* and •OH. A positive correlation existed between NO3−/NO2− concentration and the BPA degradation rate. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis identified the primary BPA photodegradation products, formed mainly through oxidative degradation, hydroxyl substitution, nitration, and chlorination pathways. Elucidating these photodegradation mechanisms provides valuable insights into the environmental fate and potential ecological risks of BPA in aquaculture environments. This knowledge can inform strategies for marine environmental protection and the development of sustainable practices.

Chondroitin Sulfate Derivative Cross-Linking of Decellularized Heart Valve for the Improvement of Mechanical Properties, Hemocompatibility, and Endothelialization.

Tissue-engineered heart valve (TEHV) has emerged as a prospective alternative to conventional valve prostheses. The decellularized heart valve (DHV) represents a promising TEHV scaffold that preserves the natural three-dimensional structure and retains essential biological activity. However, the limited mechanical strength, fast degradation, poor hemocompatibility, and lack of endothelialization of DHV restrict its clinical use, which is necessary for ensuring its long-term durability. Herein, we used oxidized chondroitin sulfate (ChS), one of the main components of the extracellular matrix with various biological activities, to cross-link DHV to overcome the above problems. In addition, the ChS-adipic dihydrazide was used to react with residual aldehyde groups, thus preventing potential calcification. The results indicated notable enhancements in mechanical properties and resilience against elastase and collagenase degradation in vitro as well as the ability to withstand extended periods of storage without compromising the structural integrity of valve scaffolds. Additionally, the newly cross-linked valves exhibited favorable hemocompatibility in vitro and in vivo, thereby demonstrating exceptional biocompatibility. Furthermore, the scaffolds exhibited traits of gradual degradation and resistance to calcification through a rat subcutaneous implantation model. In the rat abdominal aorta implantation model, the scaffolds demonstrated favorable endothelialization, commendable patency, and a diminished pro-inflammatory response. As a result, the newly constructed DHV scaffold offers a compelling alternative to traditional valve prostheses, which potentially advances the field of TEHV.

Stimuli-Responsive mRNA Vaccines to Induce Robust CD8+ T Cell Response via ROS-Mediated Innate Immunity Boosting.

The messenger RNA (mRNA) vaccines hold great significance in contagion prevention and cancer immunotherapy. However, safely and effectively harnessing innate immunity to stimulate robust and durable adaptive immune protection is crucial, yet challenging. In this study, we synthesized a library of stimuli-responsive bivalent ionizable lipids (srBiv iLPs) with smart molecular blocks responsive to esterase, H2O2, cytochrome P450, alkaline phosphatase, nitroreductase, or glutathione (GSH), aiming to leverage physiological cues to trigger fast lipid degradation, promote mRNA translation, and induce robust antitumor immunity via reactive oxygen species (ROS)-mediated boosting. After subcutaneous immunization, esterase-responsive vaccine (eBiv-mVac) was rapidly internalized and transported into the draining lymph nodes. It then underwent fast decaging and self-immolative degradation in esterase-rich antigen-presenting cells, releasing sufficient mRNA for antigen translation and massive reactive quinone methides to elevate ROS levels. This resulted in broad activation of innate immunity to boost T cell response, prompting a large number of primed antigen-specific CD8+ T cells to circulate and infiltrate into tumors (>1000-fold versus unvaccinated control), thereby orchestrating innate and adaptive immunity to control tumor growth. Moreover, by further combining our vaccination strategy with immune checkpoint blockade, we demonstrated a synergism that significantly amplified the magnitude and function of antigen-specific CD8+ T cells. This, in turn, caused potent systemic antitumor efficacy and prolonged survival with high complete response rate in xenograft and metastasis models. Overall, our generalized stimuli-responsive mRNA delivery platform promises a paradigm shift in the design of potent vaccines for cancer immunotherapy, as well as effective and precise carriers for gene editing, protein replacement, and cell engineering.

Nitroreductase DnrA, Utilizing Strategies Secreted in Bacillus sp. Za and SCK6, Enhances the Detoxification of Acifluorfen.

The residues of acifluorfen present a serious threat to the agricultural environment and sensitive crops. DnrA, a nitroreductase, is an intracellular enzyme that restricts the application of wild-type Bacillus sp. Za in environmental remediation. In this study, two strategies were employed to successfully secrete DnrA in strains SCK6 and Za, and the secretion expression conditions were optimized to achieve rapid degradation of acifluorfen. Under the optimal conditions, the relative activities of the DnrA supernatant from strains SCK6-D and Za-W were 3.06-fold and 3.53-fold higher than that of strain Za, respectively. While all three strains exhibited similar tolerance to different concentrations of acifluorfen, strains SCK6-D and Za-W demonstrated significantly faster degradation efficiency compared to strain Za. Furthermore, the DnrA supernatant from strains SCK6-D and Za-W could effectively reduce the toxicity of acifluorfen on maize and cucumber seedlings. This study provides an effective technical approach for the rapid degradation of acifluorfen.

Ternary stabilization strategies for succinonitrile-based in situ polymerized electrolyte enabling high-performance solid lithium metal batteries

Solid-state lithium metal batteries with high energy density and safety have gained increasing attention due to their potential applications. However, the practical use of solid electrolytes is hindered by several challenges. These include poor compatibility at the electrode–electrolyte interface, low ionic conductivity at room temperature, and fast capacity degradation. To address these issues, here we propose ternary strategies by in-situ cross-linked plastic crystal electrolyte (in-situ PCE) based on succinonitrile (SN). Through the in-situ polymerization of SN with polyacrylonitrile/poly(vinylidene difluoride) (PAN/PVDF) nanofibers separator, excellent mechanical strength and compatibility at the electrode–electrolyte interface are achieved. The cross-linked structure of thermally polymerized ethoxylated trimethylolpropane triacrylate (ETPTA) immobilizes the SN molecule, preventing its contact with the lithium metal and inhibiting irreversible side reactions. Additionally, a LiF-rich passivation layer is employed to further protect the SN at the electrolyte-lithium metal interface. The dual protection from ETPTA and LiF offers excellent stability to lithium. Hence, the in-situ PCE exhibits high ionic conductivity (0.79 mS cm−1 at 30 °C) and wide electrochemical window (4.56 V, vs Li+/Li). The cells exhibit excellent cycling stability and high-rate performance. LiFePO4//Li cells retain 96.6 % capacity after 1000 cycles at 10C rate. This study provides valuable insights into the development of high-performance solid-state electrolytes.

Overcome the trade-off in electro-fenton chemistry for in situ H2O2 generation-activation by tandem CoFe bimetallic single-atom configuration

Dual-atomic catalysts (DACs) demonstrated remarkable potential in addressing key challenges in electro-Fenton (EF) processes. In this study, we synthesized an EF DACs comprising both CoN4 and FeN4 sites, which was achieved a high H2O2 generation rate (1.68 mM−1h−1) and 100 % bisphenol A degradation efficiency via successive two-electron oxygen reduction and one-electron Fenton reactions (2e− ORR + 1e− Fenton). Our findings indicated that the single-atom nitrogen coordination of CoN4 and FeN4 sites plays crucial roles in regulating the adsorption of key intermediates of *OOH and *H2O2. The bimetallic sites independently regulated the binding energies of *OOH on CoN4 (pyrrole-type) for favorable H2O2 generation and its subsequent activation on adjacent FeN4 (pyridine-type). Thus, the dual-site engineering addresses the trade-off of in situ H2O2 generation-activation in EF chemistry, realizing high electron utilization efficiency and fast pollutant degradation toward efficient and sustainable water treatment.

Physio-chemical degradation of single-use plastics in natural weather and marine environments

Plastic pollution has reached concerning levels globally, with single-use plastic products (SUPs) comprising at least 50% of plastic waste. This study investigates the physical and chemical degradation of frequently used SUPs, including petroleum-based and bio-based plastics, in natural Northern European coastal weather and marine environments over a three-year period from 2019 to 2022. Addressing a critical knowledge gap, this research was based on a hypothesis that real-world ageing studies on SUPs would produce more accurate time- and process-lines for their transformation from macro-to microplastics than are available today based on the modeling studies more frequently used. The study employs optical examination, mechanical testing, Fourier Transform Infrared (FTIR) spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS) to determine and relate physical and chemical changes with time. The results indicate that SUPs undergo significantly faster degradation in natural weather than predicted to date. Photooxidation emerges as the primary degradation pathway for all SUPs, emphasizing the role of light in plastic breakdown. Importantly, physical degradation to microplastics in natural environments is not always associated with significant chemical changes such as breaking chemical bonds. Black SUPs exhibit greater resistance to visible light and ultraviolet radiation than equivalent white and transparent examples. In marine environments, SUPs degrade measurably slower than in air, their degradation slowing with increasing distance from the water surface. Our findings indicate the urgent need for strategies that mitigate the impacts of photo-oxidation of SUPs. Such strategies may include a focus on the removal of post-use SUPs from pavements, roads, beaches, and water surfaces where photo-oxidation is faster than underwater and underground. Preferential use of black SUPs over white or transparent should also be considered.

The smart nanocarrier containing zein/starch co-biopolymers enhanced by graphitic carbon nitride; exploring opportunities in brain cancer treatment

In this investigation, we present an innovative pH-responsive nanocomposite designed to address challenges associated with using 5-Fluorouracil (5-FU) in cancer therapy. The nanocomposite containing zein (Z), starch (S), and graphitic carbon nitride (g-C3N4) macromolecules is synthesized by a water-in-oil-in-water (W/O/W) double emulsion technique, serving as a carrier for 5-FU. The S/Z hydrogel matrix's entrapment and loading efficiency are greatly improved by adding g-C3N4 nanosheets, reaching noteworthy values of 45.25 % and 86.5 %, respectively, for drug loading efficiency and entrapment efficiency. Characterization through FTIR and XRD validates the successful loading of 5-FU, elucidating the chemical bonding within the nanocomposite and crystalline characteristics. Structural analysis using FESEM, along with DLS and zeta potential measurements, reveals an average nanocomposite size of 193.48 nm, indicating a controlled structure, and a zeta potential of −42.32 mV, signifying a negatively charged surface. Studies on the in vitro release of drugs reveal that 5-FU is delivered more effectively and sustainably in acidic environments than in physiological circumstances. This highlights the fact that the created nanocarrier is pH-sensitive. Modeling release kinetics involves finding the right mathematical conditions representing underlying physicochemical processes. Employing curve-fitting techniques, predominant release mechanisms are identified, and optimal-fitting kinetic models are determined. The Baker kinetic model performed best at pH 7.4, indicating that the leading cause of the drug release was polymer swelling. In contrast, the Higuchi model was most accurate for drug release at pH 5.4, illuminating the diffusion and dissolution mechanisms involved in diffusion. To be more precise, the mechanism of release at pH 7.4 and 5.4 was anomalous transport (dissolution-controlled), according to the Korsmeyer-Peppas mathematical model. The pH-dependent swelling and degradation behavior of S/Z/g-C3N4@5-FU nanocomposite showed higher swelling and faster degradation in acidic environments compared to neutral conditions. Crucially, outcomes from the MTT test affirm the significant cytotoxicity of the 5-FU-loaded nanocomposite against U-87 MG brain cancer cells, while simultaneously indicating non-toxicity towards L929 fibroblast cells. These cumulative findings underscore the potential of the engineered S/Z/g-C3N4@5-FU as a productive and targeted therapeutic approach for cancer cells.

Optimizing Li Plating Behavior via Controlling Areal Capacity of a Cathode for Cycling Stability on 600 W h kg-1 Lithium-Metal Batteries.

To meet the requirements of long-range electric vehicles and aviation, the high-mass-loading electrode with high areal capacity is a promising solution to realize ultrahigh-energy lithium-metal batteries (LMBs). However, enabling the operation of high mass loading with a long cycling life is still a challenge without in-depth investigation. Herein, we figured out that the polarization appearing in the cycled lithium-metal anodes (LMAs) is responsible for the poor cycling of LMBs with high mass loading. Moreover, the origin of fast degradation of LMAs is affected by mass loading through the Li plating process, which is decided by the Li plating morphology. Hence, manipulating the mass loading can directly promote lithium reversibility and further mitigate cell polarization in LMBs, endowing high-mass-loading LMBs with excellent cycling stability. Consequently, we achieved an ultrahigh energy density (605 W h kg-1) of a 10.1 A h pouch cell with an excellent retention of 91.7% capacity and 86% energy after 50 cycles. The feasible strategy points out a promising approach for designing high-energy-density LMBs in the future.

Biodegradation behavior of poly (glycolic acid) (PGA) and poly (butylene adipate-co-terephthalate) (PBAT) blend films in simulation marine environment

Polyglycolic acid (PGA) and poly (butylene adipate-co-terephthalate) (PBAT), as widely applied biodegradable polymers, the degradation behavior of their blends in marine environments has not been proven. This study investigated the changes of macroscopic and microscopic morphology, thermal properties, crystalline and chemical structure, degradation rate of PGA/PBAT blends with different ratios in the simulation marine environment containing sediments and marine organisms. The results showed that degradation primarily occurred due to ester bond breakage, and PGA exhibited a faster degradation rate than PBAT films. The amorphous region degraded more rapidly than the crystalline region, and the thermal stability of the materials decreased. The degradation of PGA and PBAT blends followed their respective single degradation laws and the compatibility of blend samples decreased after degradation. The degradation rate of the samples was obtained by measuring the biochemical oxygen demand, which indicated that a higher PGA content could result in a faster degradation rate for PGA/PBAT films. This study provides an efficient method for constructing materials with controlled biodegradability.

In-vitro and in-silico analyses of the thrombolytic potential of green kiwifruit

Cardiovascular diseases (CVDs), mainly caused by thrombosis complications, are the leading cause of mortality worldwide, making the development of alternative treatments highly desirable. In this study, the thrombolytic potential of green kiwifruit (Actinidia deliciosa cultivar Hayward) was assessed using in-vitro and in-silico approaches. The crude green kiwifruit extract demonstrated the ability to reduce blood clots significantly by 73.0 ± 1.12% (P < 0.01) within 6 h, with rapid degradation of Aα and Bβ fibrin chains followed by the γ chain in fibrinolytic assays. Molecular docking revealed six favorable conformations for the kiwifruit enzyme actinidin (ADHact) and fibrin chains, supported by spontaneous binding energies and distances. Moreover, molecular dynamics simulation confirmed the binding stability of the complexes of these conformations, as indicated by the stable binding affinity, high number of hydrogen bonds, and consistent distances between the catalytic residue Cys25 of ADHact and the peptide bond. The better overall binding affinity of ADHact to fibrin chains Aα and Bβ may contribute to their faster degradation, supporting the fibrinolytic results. In conclusion, this study demonstrated the thrombolytic potential of the green kiwifruit-derived enzyme and highlighted its potential role as a natural plant-based prophylactic and therapeutic agent for CVDs.

Bifunctional naringenin-laden gelatin methacryloyl scaffolds with osteogenic and anti-inflammatory properties

ObjectiveTo fabricate and characterize an innovative gelatin methacryloyl/GelMA electrospun scaffold containing the citrus flavonoid naringenin/NA with osteogenic and anti-inflammatory properties. MethodsGelMA scaffolds (15 % w/v) containing 0/Control, 5, 10, or 20 % of NA w/w were obtained via electrospinning. The chemical composition, fiber morphology/diameter, swelling/degradation profile, and NA release were investigated. Cytotoxicity, cell proliferation, adhesion and spreading, total protein/TP production, alkaline phosphatase/ALP activity, osteogenic genes expression (OCN, OPN, RUNX2), and mineralized nodules deposition/MND with human alveolar bone-derived mesenchymal stem cells (aBMSCs) seeded on the scaffolds were assessed. Moreover, aBMSCs seeded on the scaffolds and stimulated with tumor necrosis factor-alpha/TNF-α were submitted to collagen, nitric oxide/NO, interleukin/IL-1α, and IL-6 production assessment. Data were analyzed using ANOVA and t-student/post-hoc tests (α = 5 %). ResultsNA-laden scaffolds presented increased fiber diameter, lower swelling capacity, and faster degradation profile over 28 days (p < 0.05). NA release was detected over time. Cell adhesion and spreading, and TP production were similar between GelMA and GelMA+NA5 % scaffolds, while cell proliferation, ALP activity, OCN/OPN/RUNX2 gene expression, and MND were higher for GelMA+NA5 % scaffolds (p < 0.05). Cells seeded on control scaffolds and TNF-α-stimulated presented higher levels of NO, IL-1α/IL-6, and lower levels of collagen (p < 0.05). In contrast, cells seeded on GelMA+NA5 % scaffolds showed downregulation of inflammatory markers and higher collagen synthesis (p < 0.05). SignificanceGelMA+NA5 % scaffold was cytocompatible, stimulated aBMSCs proliferation and differentiation, and downregulated inflammatory mediators’ synthesis, suggesting its therapeutic effect as a multi-target bifunctional scaffold with osteogenic and anti-inflammatory properties for bone tissue engineering.

Synthesis and characterization of SiO2 nanoparticles reinforced 3D printable gelatin/PVA/guar gum/ hydroxypropyl methylcellulose-based biocomposite hydrogel

Biocomposite-based hydrogels have engrossed snowballing devotion due to their hydrophilic, biodegradability, and biocompatibility properties. 3D printing of biocomposite-based hydrogels has emerged in numerous fields, such as pharmaceutical, biomedical, and food engineering, as it involves fabricating complex and customized geometrical components. The present works focus on developing new 3D printable biocomposite hydrogels using gelatin, polyvinyl alcohol, guar gum, and hydroxypropyl methylcellulose (HMC). Hydroxyapatite (HAp) and SiO2 nanoparticles are used as supplemental materials to tailor the properties of hydrogels. The composition has been optimized for enhanced printability through rheological characterization. The developed hydrogel, chemically cross-linked with glyoxal, has been assessed for its static and dynamic mechanical properties, swelling, thermal stability, and degradation characteristics. By incorporating supplements such as HAp, HMC, and SiO2 into the gelatin/polyvinyl alcohol (PVA)/guar gum hydrogel, a compressive and tensile strength of 4.64 MPa, and 71.76 kPa was achieved with better recovery efficiency under cyclic compression and tensile tests. The highest storage modulus of 0.6 MPa at 100 Hz was noticed. A sorbing capacity of 208.98 % was perceived in 70 h. The hydrogel demonstrated quick creep recovery and stress relaxation properties with faster degradation behavior than the PVA hydrogel. Based on the outcomes attained in the present study, it is inferred that the reported biocomposite hydrogels are promising materials for pharmaceutical and biomedical applications.

Optimizing bimetallic-insect exuviate melanin composite cathodes using response surface methodology to enhance the H2O2 yield and selectivity of the electro-Fenton process

Electro-Fenton is a fast and efficient oxidative degradation technology for treating many refractory organic substances. However, the poor electrochemical performance and power generation capacity of the cathode during electro-Fenton treatment limit H2O2 generation and pollutant removal. A FeCu bimetal–melanin cathode catalyst with high H2O2 production, low Fe3+ formation, and low resistance was optimized using response surface methodology. The composite desirability coefficient was as high as 0.9281, indicating that the two-factor setting conditions yielded the optimal response results. The synergistic effect between Fe and Cu and the ionic conductivity of melanin promote the conversion between Fe2+ and Fe3+ and improve the charge transfer ability of the cathode. The optimized Fe–Cu–Me cathodic catalyst had the highest H2O2 generation (217.91 ± 4.65 mg/L) and the lowest resistance value (190.33 Ω), 4.88 times and 5.05 % that of the unmodified cathode, respectively; also the lowest Fe3+ generation was 32 % and 73 % that of the Fe and FeCu cathodic catalysts, respectively. Moreover, the optimized Fe–Cu–Me cathode catalyst exhibited up to 80 % selectivity for 2-electron oxygen reduction reaction-catalyzed H2O2 generation based and excellent O2 and H2O2 adsorption performance on ring disk electrode analysis and density function theory calculation. This study is the first to use FeCu bimetals combined with insect exuviate melanin as a cathode catalyst for the in situ generation of cathodic H2O2. The high performance and stability of the fabricated electrocatalyst can be used in the subsequent treatment of wastewater through the electro-Fenton process, providing an innovative approach to improve the performance of the cathode.

Capacity Degradation of Zero-Excess All-Solid-State Li Metal Batteries Using a Poly(ethylene oxide) Based Solid Electrolyte.

Solid-state polymer electrolytes (SPEs), such as poly(ethylene oxide) (PEO), have good flexibility when compared to ceramic-type solid electrolytes. Therefore, it could be an ideal solid electrolyte for zero-excess all-solid-state Li metal battery (ZESSLB), also known as anode-free all-solid-state Li battery, development by offering better contact to the Cu current collector. However, the low Coulombic efficiencies observed from polymer type solid-state Li batteries (SSLBs) raise the concern that PEO may consume the limited amount of Li in ZESSLB to fail the system. Here, we designed ZESSLBs by using all-ceramic half-cells and an extra PEO electrolyte interlayer to study the reactivity between PEO and freshly deposited Li under a real battery operating conduction. By shuttling active Li back from the anode to the cathode, the PEO SPEs can be separated from the ZESSLBs for experimental studies without the influence from cathode materials or possible contamination from the usage of Li foil as the anode. Electrochemical cycling of ZESSLBs shows that the capacities of ZESSLBs with solvent-free and solvent-casted PEO SPEs significantly degraded compared to the ones with Li metal as the anode for the all-solid-state Li batteries. The fast capacity degradation of ZESSLBs using different types of PEO SPEs is evidenced to be associated with Li reacting with PEO, residual solvent, and water in PEO and dead Li formation upon the presence or absence of residual solvent. The results suggest that avoiding direct contact between the PEO electrolyte and deposited lithium is necessary when there is only a limited amount of Li available in ZESSLBs.

Efficient adsorption and rapid electrochemical degradation of methyl methacrylate (MMA) by three-dimensional nanostructured carbon anode

Methyl methacrylate (MMA) is a widely used oxygen-containing volatile organic compound, functioning as both an organic solvent and additive. Therefore, the advancement of effective methods for MMA removal is of great significance. In this study, three-dimensional nanostructured carbon (CNTs/CC) anode materials were prepared through the in-situ growth of carbon nanotubes (CNTs) on carbon cloth (CC) using chemical vapor deposition (CVD). The prepared material showed outstanding adsorption-electrocatalytic degradation performance towards MMA, with a saturated adsorption capacity of 2033 mg·g−1 and complete degradation achieved after 90 min of electrification at a 100 mg·L−1 MMA concentration. The electrochemically active surface area increased to 29.8 cm2 with an Rs value of 2.35 Ω for the CNTs/CC-2 anode material, leading to enhanced ·OH generation capability and faster degradation rates. The material also exhibited excellent reusability over thirteen cycles of adsorption-electrochemical degradation of MMA, with a degradation efficiency consistently above 92 %. This research provides valuable insights for developing new materials and technologies for MMA degradation.

Use of Polylactic Acid Added with Calcium Oxide and 3-Iodo-2-Propynly Butyl Carbamate as an Antifungal Agent and Bio-degradable Soil Remediator

This work studied the use of polylactic acid added with calcium oxide (CaO) and 3-Iodo-2-propynly butyl carbamate (IPBC) for agricultural applications. CaO content of 30 pph was fixed, while IPBC contents were varied at 0, 2.5, 5.0, 7.5 and 10.0 ppm in the polymer matrix. All ingredients were mixed by the extrusion process for receiving the PLA, PLA/CaO, and PLA/CaO/IPBC granules. The pH value, antifungal activities of Phytophthora parasitica, tomato growth, and disposal degradation were also investigated. The experimental results indicated that the acidic condition of the PLA granules increased with increasing IPBC contents but was compromised by CaO. An IPBC was an effective antifungal agent. It was also promoted and activated by CaO. Growth of P. parasitica can be inhibited by CaO synergized IPBC for the PLA/CaO granules with four different IPBC contents and the PLA/CaO granules with the four different IPBC contents were an effective antifungal agent. A PLA/CaO granule with an IPBC content of 2.5 ppm can be developed to compete with an unused condition. A PLA/CaO granule with an IPBC content of 10 ppm was recommended for agricultural applications. A PLA/CaO/IPBC 10 acted as an effective antifungal agent and compostable for soil bioremediatory before planting. Over the 45-day experimental period, the maximum percentage of weight loss of a PLA/CaO granule with an IPBC content of 10 ppm was influenced by moisture and initial PLA loading. A PLA/CaO granule with an IPBC content of 10 ppm (47.2%) had a faster degradation rate than a PLA/CaO granule (45.3%) and a neat PLA granule (15.0%).

Chronic kidney disease: a contraindication for using biodegradable magnesium or its alloys as potential orthopedic implants?

Magnesium (Mg) has gained widespread recognition as a potential revolutionary orthopedic biomaterial. However, whether the biodegradation of the Mg-based orthopedic implants would pose a risk to patients with chronic kidney disease (CKD) remains undetermined as the kidney is a key organ regulating mineral homeostasis. A rat CKD model was established by a 5/6 subtotal nephrectomy approach, followed by intramedullary implantation of three types of pins: stainless steel, high pure Mg with high corrosion resistance, and the Mg–Sr–Zn alloy with a fast degradation rate. The long-term biosafety of the biodegradable Mg or its alloys as orthopedic implants were systematically evaluated. During an experimental period of 12 weeks, the implantation did not result in a substantial rise of Mg ion concentration in serum or major organs such as hearts, livers, spleens, lungs, or kidneys. No pathological changes were observed in organs using various histological techniques. No significantly increased iNOS-positive cells or apoptotic cells in these organs were identified. The biodegradable Mg or its alloys as orthopedic implants did not pose an extra health risk to CKD rats at long-term follow-up, suggesting that these biodegradable orthopedic devices might be suitable for most target populations, including patients with CKD.

Simple on-site extraction and GC-MS analysis of rotenone and degradation products for monitoring invasive fish eradication treatments in fresh and brackish waters

The introduction of invasive fish species to aquatic ecosystems has been demonstrated to cause disastrous ecological effects. Current conservation strategies regard rotenone-containing piscicide formulations, such as commercial product CFT Legumine, as a potentially viable alternative to the cumbersome traditional approaches to fish eradication. This consideration relies on the fast degradation of rotenone and its relatively rapid dissipation from the environment. Piscicide treatments in fragile aquatic ecosystems should thus monitor not only rotenone concentrations following application, but also other byproducts and degradation products. We present a methodology for the analysis of rotenoids in fresh and brackish waters that addresses two main challenges: the accurate determination of applied concentrations in different salinity concentrations by performing a simplified on-site solid-phase extraction, overcoming the fast degradation of rotenone in sample storage conditions, and the selective analysis of rotenoid byproducts and degradation products by gas chromatography coupled to mass spectrometry. Limits of quantification were below the ecological no-effect concentration of rotenone (2 µg/L) and average recoveries exceeded 80%. Accuracy (compared to expected values) and precision (deviation of replicates) ranged from 78 to 103% and 3 to 14%, respectively, across various rotenoid concentrations. These metrics are more than satisfactory for the intended application of this simplified procedure. The method was applied to piscicide-treated samples, revealing significant and fast degradation of parent rotenoids in storage conditions, as well as a non-negligible accumulation of rotenone in the particulate fraction of water that could impact the effectivity of eradication efforts.

Water-saving and water-spending strategy: The physiological, proteomic and metabolomic investigation of wheat response to drought and the following recovery

Drought as water deficit in the soil represents the most commonly occurring and the most variable environmental stress factor worldwide. Plants have evolved various strategies to cope with drought stress in relation to their other needs such as the necessity to supply carbon in plants with a C3 type of photosynthetic assimilation. In the present study, two wheat cultivars, Baletka and Tobak, representing two contrasting water management strategies, were studied at physiological, proteomic and metabolomic levels to provide a complex view on their phenotypic responses to drought treatment and subsequent recovery. Physiological characteristics clearly distinguished Baletka and Tobak and, moreover, in water-saving Baletka, both proteomics and metabolomics analyses revealed significant remodelling of cell wall, changes in endocytosis and cell signalling, and, especially, changes in synthesis of other defence proteins and LTI65kDa protein (also known as RD29B protein) which has been detected in wheat for the first time. LEA1 protein was proposed as a component of drought stress memory in Baletka. An amazing finding was the enhanced accumulation of oxalate oxidase implying enhanced oxalate oxidase activity leading to faster degradation of oxalate with the simultaneous gain of two molecules of CO2 which may represent an alternative source of CO2 for C3 plants exposed to drought stress.