Exceptional anti-toxic growth of water spinach in arsenic and cadmium co-contaminated soil remediated using biochar loaded with Bacillus aryabhattai.

Functionalized biochars are crucial for simultaneous soil remediation and safe agricultural production. However, a comprehensive understanding of the remediation mechanism and crop safety is imperative. In this work, the all-in-one biochars loaded with a Bacillus aryabhattai (B10) were developed via physisorption (BBC) and sodium alginate embedding (EBC) for simultaneous toxic As and Cd stabilization in soil. The bacteria-loaded biochar composites significantly decreased exchangeable As and Cd fractions in co-contaminated soil, with enhanced residual fractions. Heavy metal bioavailability analysis showed a maximum CaCl2-As concentration decline of 63.51% and a CaCl2-Cd decline of 50.96%. At a 3% dosage of composite, rhizosphere soil showed improved organic matter, cation exchange capacity, and enzyme activity. The aboveground portion of water spinach grown in pots was edible, with final As and Cd contents (0.347 and 0.075 mg·kg⁻¹, respectively) meeting food safety standards. Microbial analysis revealed the composite's influence on the rhizosphere microbial community, favoring beneficial bacteria and reducing plant pathogenic fungi. Additionally, it increased functional microorganisms with heavy metal-resistant genes, limiting metal migration in plants and favoring its growth. Our research highlights an effective strategy for simultaneous As and Cd immobilization in soil and inhibition of heavy metal accumulation in vegetables.

Response of tomatoes to inactivated endophyte LSE01 under combined stress of high-temperature and drought.

Endophytes can assist crops in adapting to high temperatures and drought conditions, thereby reducing agricultural losses. However, the mechanism through which endophytes regulate crop resistance to high temperatures and drought stress remains unclear, and concerns regarding safety and stability exist with active endophytes. Thus, heat-treated endophytic bacteria LSE01 (HTB) were employed as a novel microbial fertilizer to investigate their effects on plant adaptation to high temperatures and drought conditions. The results indicated that the diameter and weight of tomatoes treated with HTB under stress conditions increased by 23.04% and 71.15%, respectively, compared to the control. Tomato yield did not significantly decrease compared to non-stress conditions. Additionally, the contents of vitamin C, soluble sugars, and proteins treated with HTB increased by 18.81%, 11.54%, and 99.75%, respectively. Mechanistic research revealed that HTB treatment enhances tomato's stress resistance by elevating photosynthetic pigment and proline contents, enhancing antioxidant enzyme activities, and reducing the accumulation of MDA. Molecular biology research demonstrates that HTB treatment upregulates the expression of drought-resistant genes (GA2ox7, USP1, SlNAC3, SlNAC4), leading to modifications in stomatal conductance, plant morphology, photosynthetic intensity, and antioxidant enzyme synthesis to facilitate adaptation to dry conditions. Furthermore, the upregulation of the heat-resistant gene (SlCathB2-2) can increases the thickness of tomato cell walls, rendering them less vulnerable to heat stress. In summary, HTB endows tomatoes with the ability to adapt to high temperatures and drought conditions, providing new opportunities for sustainable agriculture.

Use of Various UVC Photofunctionalization Times to Modify Surface Characteristics and Enhance the Biologic Activity of SLA Titanium.

PURPOSE: To evaluate the effect of ultraviolet-C light (UVC) photofunctionalization treatment time on the biologic activity of airborne particle-abraded and acid-etched (SLA) titanium surfaces and to analyze its physical and chemical mechanisms. MATERIALS AND METHODS: SLA titanium was treated with UVC light for different lengths of time (10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours), and then changes to its surface characteristics were evaluated via electron microscope scanning, X-ray photoelectron spectroscopy (XPS), water contact angle measurement, and zeta potential measurement. The effect of UVC photofunctionalization on the biologic processes of SLA titanium surfaces was assessed by analyzing the bovine serum albumin adsorption, adhesion, proliferation, morphology, and alkaline phosphatase activity of MG-63 cells. RESULTS: UVC irradiation did not change the topography of SLA titanium surfaces. As treatment times increased, the water contact angle decreased from 120 degrees to 0 degrees, and the hydrocarbon content decreased. Zeta potential testing showed increased surface potential of photofunctionalized titanium. In vitro testing showed that cell adhesion, proliferation, morphology, and alkaline phosphate (ALP) activity on titanium surfaces were significantly improved by UVC photofunctionalization. CONCLUSIONS: UVC photofunctionalization can improve the biologic activity of SLA titanium surfaces by removing hydrocarbons and increasing the surface potential of titanium.

An ultrasensitive dietary caffeic acid electrochemical sensor based on Pd-Ru bimetal catalyst doped nano sponge-like carbon.

Caffeic acid (CA) is widely present in the human daily diet, and a reliable CA detection method is beneficial to food safety. Herein, we constructed a CA electrochemical sensor employing a glassy carbon electrode (GCE) which was modified by the bimetallic Pd-Ru nanoparticles decorated N-doped spongy porous carbon obtained by pyrolysis of the energetic metal-organic framework (MET). The high-energy bond N-NN in MET explodes to form N-doped sponge-like carbon materials (N-SCs) with porous structures, boosting the adsorptive capacity for CA. The addition of Pd-Ru bimetal improves the electrochemical sensitivity. The linear range of the PdRu/N-SCs/GCE sensor is 1 nM-100 nM and 100 nM-15 µM, with a low detection limit (LOD) of 0.19 nM. It has a high sensitivity (55 µA/µM) and repeatability. The PdRu/N-SCs/GCE sensor has been used to detect CA in actual samples of red wine, strawberries, and blueberries, providing a novel approach for CA detection in food analysis.

Bioleaching and immobilizing of copper and zinc using endophytes coupled with biochar-hydroxyapatite: Bipolar remediation for heavy metals contaminated mining soils.

Copper and zinc are toxic heavy metals in soils that require development of feasible strategies for remediation of contaminated soils around the mine areas. In this study, the processing conditions and mechanisms of immobilization and bioleaching for remediation of highly contaminated soils with heavy metals are investigated. Soil remediation is carried out using a bioleaching-immobilization bipolar method. The results show that LSE03 bacteria provide efficient leaching result and immobilization on Cu2+ and Zn2+. Among the bacterial metabolites, cis, cis-muconic acid and isovaleric acid play major roles in the bioleaching process. The bacterial extracellular polymeric substances are rich in a variety of organic acids that show a significant decrease in content after the adsorption process, indicating that all of these substances are involved in the binding of heavy metals. Characterization of the endophytes and immobilizing agents with FTIR, TEM-mapping, and XPS techniques reveal the ability of both bacteria and composites to adsorb Cu-Zn as well as the main functional groups of -OH, -COOH, -PO43-, and -NH. According to the heavy metals species analyses, competitive adsorption experiments, and bioleaching desorption experiments, it is planned to carry out the bipolar remediation of contaminated soil through immobilization followed by bioleaching process. After bipolar remediation processing, 97.923% and 96.387% of available Cu and Zn are respectively removed. Soils fertility significantly increases in all cases. Our study provides a green, practical, and environmentally friendly treatment method for soils contaminated with high concentrations of heavy metals.

Improvement in Osseointegration of Titanium Dental Implants After Exposure to Ultraviolet-C Light for Varied Durations: An Experimental Study in Beagle Dogs.

PURPOSE: Ultraviolet-mediated photofunctionalization is a valid technology for enhancing the osseointegration of titanium implants. However, there is no consensus on the effective exposure time to ultraviolet light. The objective of this study was to evaluate the effect of different exposure times of ultraviolet-C (UVC) light on aged titanium implants and explore the optimal treatment duration of UVC photofunctionalization for osseointegration in an animal model. METHODS: Eight male beagle dogs (n = 48) were divided into a control group (n = 12) and 3 experimental groups (n = 12/12/12) which received 4-week-old implants without UVC treatment (C) or treated with UVC for 1/6 hour, 1/2 hour, and 1 hour (UVC-1/6 hour, UVC-1/2 hour, UVC-1 hour) immediately before placement. All the implants were placed 12 weeks after mandibular premolars extraction. Four dogs were euthanized after 4 and 12 weeks of healing, respectively. The marginal bone level and implant stability quotient were measured at implant placement and after sacrifice. Subsequently, micro-CT and histomorphometric analyses were performed following block harvesting. RESULTS: No significant difference in marginal bone loss between the UVC-untreated and UVC-treated groups was found at 4 or 12 weeks. At 4 weeks, significantly higher BV/TV and bone-implant contact were observed in the UVC groups than in the C group, irrespective of the UVC-photofunctionalization duration (BV/TV: UVC-1/6 hour 0.48 ± 0.11, UVC-1/2 hour 0.50 ± 0.06, and UVC-1 hour 0.47 ± 0.08, C 0.34 ± 0.04; bone-implant contact : UVC-1/6 hour 84.30 ± 5.02%, UVC-1/2 hour 85.82 ± 5.05%, and UVC-1 hour 84.98 ± 3.86%, C 71.69 ± 3.52%. P < .05), whereas, no significant difference was observed among the UVC groups. At 12 weeks, there were no significant differences between the C group and UVC groups. After 4 and 12 weeks of healing, no significant difference in implant stability quotient values was observed between the C group and UVC groups. CONCLUSIONS: UVC photofunctionalization improved the early osseointegration of aged titanium implants. However, the effect was not dependent on the UVC-light duration within the range from 1/6 hour to 1 hour.

Effects of Hydrofluoric Acid Concentration and Etching Time on the Bond Strength to Ceramic-coated Zirconia.

PURPOSE: To evaluate the effects of different hydrofluoric acid (HF) concentrations and etching times on the surface topography, roughness, and resin bond strength to ceramic-coated zirconia (CC), and to compare them with the effects of alumina air-abrasion combined with 10-MDP (AA). MATERIALS AND METHODS: AA and CC specimens were divided into 12 groups (N = 10). The CC groups were etched with HF at different concentrations (5% or 9.5%) for various durations (0 min, 1 min, 2 min, 3 min, 5 min or 10 min). The surface morphology was analyzed using SEM. Energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD) were performed for chemical and crystalline-phase analyses. Surface roughness (Ra) and shear bond strength (SBS) were recorded and statistically analyzed. RESULTS: The SBS of CC groups initially increased, but then decreased with etching time for both HF acid concentrations. The 9.5% HF group displayed more marked topographical changes and higher Ra compared with the 5% HF group for the same etching period. Mean SBS was lower in the AA group compared with the CC groups etched with 5% HF for 2-10 min and 9.5% HF for 1-3 min (p < 0.05). CONCLUSIONS: Different HF concentrations and etching times influenced the surface topography, roughness, and resin bond strength of/to ceramic-coated zirconia. Etching with 5% HF for 5 min and with 9.5% HF for 2 min, respectively, provided the highest SBS.

A digital workflow with the virtual enamel evaluation and stereolithographic template for accurate tooth preparation to conservatively manage a case of complex exogenous dental erosion.

OBJECTIVE: This article describes a digital workflow using virtual enamel evaluation and a stereolithographic template for accurate tooth preparation for a complex exogenous dental erosion. CLINICAL CONSIDERATIONS: A 22-year-old man with different degrees of defects on the labial surface in esthetic area was diagnosed as exogenous dental erosion. The residual undamaged enamel area and depth of defect were measured and analyzed accurately by creating a digital virtual patient based on the pretreatment data. According to the different conditions of residual enamel and tooth defect, the treatment plans of porcelain veneer, crown and composite resin were chosen for corresponding involved teeth. Based on the virtual wax-up and the suggested material thickness, a template for tooth preparation was designed and three-dimensional printed. This template together with a special bur indicating the reduction depth accurately guided the teeth preparation and achieved a long-term effect. CONCLUSIONS: The virtual enamel evaluation contributes to obtaining the appropriate corresponding treatment plan objectively. The stereolithographic template effectively meets the accuracy of tooth preparation, preserving the tooth hard tissue to the greatest extent. CLINICAL SIGNIFICANCE: The digital workflow described here may provide a quantifiable evaluation method and an accurate tooth preparation method for exogenous dental erosion.

Effect of pore geometry on the fatigue properties and cell affinity of porous titanium scaffolds fabricated by selective laser melting.

Porous titanium scaffolds with different unit cell type (tetrahedron and octahedron) and pore size (500 µm and 1000 µm) were fabricated by selective laser melting (SLM), and the effects of unit cell type and pore size on their fatigue properties and cell affinity were studied. The fatigue properties were performed by static and dynamic mechanical testing, while the cell affinity was evaluated in vitro with mouse osteoblast cells. It was found that octahedron scaffolds exhibited superior static mechanical properties, longer fatigue lives and higher fatigue strength in comparison to those of tetrahedron ones. As expected, scaffolds with 1000 µm pore resulted in lower compressive properties and shorter fatigue lives compared to those with 500 µm pore. The differences were analyzed based on the unit cell structure, porosity, and manufacturing imperfections. Scanning electron microscopy (SEM) and immunofluorescence showed that cells spread better on octahedron scaffolds than those on tetrahedron ones. Meanwhile, the scaffolds with 1000 µm pore were more suitable for cell attachment and growth within the same unit cell owing to higher porosity. The comparison of different pore geometry on the mechanical and biological property provided further insight into designing an optimal porous scaffold.