Deep Cavities Research Articles

Beyond Traditional Fillings: Why Bulk-Fill Composites Are Changing the Game

This review examines the impact of bulk-fill composites in restorative dentistry, highlighting their advantages over traditional resin-based materials. Conventional composites often require multiple incremental placements, increasing technique sensitivity and the risk of restoration failure. Bulk-fill composites allow for placement in single layers of 4-6mm, reducing chairside time and procedural complexity. The review discusses innovations in formulation, including enhanced translucency and modifications in photoinitiators that support effective polymerization. Key properties such as microhardness, degree of conversion, depth of cure, and polymerization shrinkage are evaluated, showing that high-viscosity bulk fills can achieve hardness comparable to conventional composites. Various commercially available products are assessed for their clinical performance. The review ultimately emphasizes the growing acceptance of bulk-fill composites as reliable alternatives, advocating for continued research to enhance clinician confidence in their application and effectiveness in deep cavity restorations. Keywords: Bulk fill composites, posterior composites, incremental composite placement, tooth colored restoratives, polymerisation shrinkage, degree of conversion, depth of cure

Formation of vertical columnar seismic structures and seafloor depressions by groundwater discharge in drowned Miami Terrace platform and overlying deep-water carbonates, southeastern Florida

The presence of vertical cross-formational fluid migration passageways within sedimentary basins can profoundly impact aquifer and reservoir fluid-flow and their identification is fundamental to informing management of subsurface fluid resources (groundwater, oil, gas). In an onshore and offshore southeastern part of Florida, 2D/3D seismic-reflection and bathymetry data document ~153 vertical columnar structures composed of reflection disruptions up to 760 m in the height and averaging 360 m in diameter, and ~ 219 subcircular to circular seafloor depressions up to 1010 m wide. Our study focuses on these features found within the offshore shallow-marine carbonate Miami Terrace platform, which drowned approximately at the end of the middle Miocene, and within overlying Plio-Quaternary deep-water carbonate slope and drift deposits. Most columnar structures are rooted in stratiform aquifers of the Miami Terrace platform and associated with faults or fault intersections produced by Eocene and circa late Miocene tectonics. The columns commonly terminate within the platform or as subcircular depressions along an amalgamated karstic and drowning unconformity at the platform top. The columns typically stretch upwards from a zone of deep karst cavity collapse through the Miami Terrace platform with upward decreasing sag on internal reflections. Following drowning and Plio-Quaternary partial burial of the Miami Terrace platform by deep-water deposits, the subcircular depressions and faults along the platform top were points of origin for a second phase of column growth upward into the deep-water deposits. The continuation of deep platform cavity collapse and column evolution produced pockmarks along paleo-seafloors within the deep-water deposits and at the present-day sea floor. The Plio-Quaternary pockmarks formed at water depths too deep to suggest an origin related to meteoric karst above or near sea level, but rather their formation is suggested to be related to cyclic sea level falls that drove increased groundwater head and density gradients, and seafloor discharge of offshore freshened groundwater sourced from the underlying platform. Mixing of freshened groundwater and seawater at the seafloor discharge sites plausibly drove dissolution of the host deep-water deposits that contributed to the formation of the pockmarks and erosion by groundwater venting and current scouring.Seaward of the Plio-Quaternary seafloor pockmarks, at the late-middle Miocene upper slope of the Miami Terrace platform and along the regional karst/drowning unconformity is a slope-parallel band of ~188 densely distributed subcircular seafloor depressions with diameters up to 1010 m at water depths up to 663 m. It is plausible that along the upper slope, faults and fractures produced by gravity-driven slope instability and possibly tectonics formed a dense network of fluid passageways that promoted upward artesian freshened groundwater flow to sites of discharge where mixing with seawater generated limestone dissolution and the depressions. But tectonic uplift may have forced emersion and initial meteoric sinkhole formation circa late Miocene with later enhancement by freshened groundwater discharge and bottom current erosion.

Influence of Academic Training and Professional Experience on the Management of Deep Caries Lesions.

Managing caries lesions that affect the inner third of the dentin is crucial to ensuring pulp vitality; the clinician must make decisions that will affect the vitality of the tooth. Our purpose is to understand the behavior of Spanish dentists in treating deep cavities and to examine whether variations exist based on their academic training and/or years of professional experience. This study was approved by the ethics committee of the Balearic Islands CEI-IB. A survey was conducted using the SurveyMonkey platform with 11 questions, the first 4 of which focused on defining the characteristics of the respondents. The following six concerned a clinical case of deep caries in tooth number 4.7, and the last regarded the opinion of the actual treatment of the case. The survey was sent by email in April 2022. The results were analyzed with the SPSS 29.0 program using the chi-square test. A total of 347 responses were obtained (93.95%), and those surveyed stated that they apply minimal intervention concepts in their treatments, with 90.49% performing conservative dentistry treatments daily. A total of 56.48% of the respondents had bachelor's degrees, 12.39% had graduated, 33.14% had a postgraduate degree, 38.90% had a master's degree, and 17% had a doctorate. Most (40.63%) had been in professional practice for 16-30 years. Significant differences were identified regarding years of professional experience in terms of decision-making in methods of treatment and the choice of materials used for pulp protection. Likewise, significant differences were found regarding the academic training of the respondents, the cavity cleaning method selected, and the use of chemical substances for removing carious dentin. We can conclude that academic training and years of professional practice influence decision-making at some points in treating deep caries lesions.

Clinical application of iliac myocutaneous flap pedicled with deep circumflex iliac artery in repair of complex defect of lower limb with cavity

To explore the effectiveness of iliac myocutaneous flap pedicled with deep circumflex iliac artery (DCIA) on the repair of lower limb composite defect wounds with cavity. A retrospective analysis of 7 patients with lower limb composite defect wounds treated between March 2017 and September 2020 was conducted, including 4 males and 3 females, aged 24-58 years, with a median age of 37 years. The causes of injury were machine twisting injury in 2 cases, fall from height injury in 2 cases, and traffic accident injury in 3 cases. According to Gustilo-Anderson classification, there were 1 case of type Ⅲa, 4 cases of type Ⅲb, and 2 cases of type Ⅲc (combined with anterior tibial artery rupture); according to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 2 cases of type 42-C3, 2 cases of type 43-A2, and 3 cases of type 43-B1. The time from injury to admission ranged from 2 to 10 hours, with an average of 6 hours. Tibial bone defect and surrounding soft tissue defect with deep cavity were left after primary emergency debridement. In the second stage, according to the characteristics of the wound, the three-dimensional repair of the composite defect was designed with DCIA embedded iliac myocutaneous flap. The size of the iliac flap was 2.0 cm×2.0 cm×2.0 cm to 7.0 cm×3.0 cm×2.5 cm, and the size of the flap was 12.0 cm×8.0 cm to 21.0 cm×13.0 cm. The internal oblique muscle flap was harvested in size of 3.0 cm×2.0 cm×2.0 cm to 5.5 cm×4.0 cm×4.0 cm. The donor site was primarily closed. All the flaps survived after operation, except for 1 case of partial necrosis of the flap edge, which healed after secondary skin grafting, and the donor and recipient wounds healed by first intention. All patients were followed up 16-24 months, with an average of 18 months. The broken end of the bone defect healed well, and the healing time was 8-10 months, with an average of 7.3 months. At last follow-up, the shape of the flap was satisfactory, the texture was soft, and there was no abnormal hair growth, pigmentation, and so on. Only linear scar was left in the donor site, and no complication such as abdominal hernia occurred. According to Paley fracture healing scoring system, bone healing was rated as excellent in 5 cases and good in 2 cases. The limb function was satisfactory, and full weight bearing was achieved at 12-16 months after operation. According to the lower extremity functional scale (LEFS), 6 cases were excellent and 1 case was good. The iliac myocutaneous flap pedicled with DCIA is flexible in design and highly free in tissue composition, which can repair the composite defect wound of lower limbs with deep cavity in a three-dimensional way, and repair the limb shape and reconstruct weight-bearing function to the greatest extent.

The Clinical Utility of Powdered and Flowable Matrices in Wound Repair and Tissue Regeneration.

Cellular and matrix-like products come in many forms. Among them, powdered and micronized formulations have become increasingly available and popular owing to their unique properties and advantages. Powders have increased tissue contact which many believe can enhance granulation tissue formation, they fill irregular and deep cavities, and they can be used in concert with sheet-like products and skin grafts for improved healing. Despite their advantages, powdered products do have certain limitations that hinder their use, including poor insurance coverage and a lack of CPT coding for adequate reimbursement in an outpatient setting, making their use primarily limited to the operating room. Also, most published data on powdered products consists of smaller case studies and case series, with few reports evaluating the efficacy and utility of powdered formulations compared to their sheet-like progenitors. In this manuscript, we organize available powdered matrix products by type of substrate: xenograft, allograft, placental-based, and synthetic, and review the data in support of various products in specific wound types. This review of the supporting literature provides the current body of evidence on the utility of powdered matrices in wounds.

Structural and biochemical insights into the molecular mechanism of N-acetylglucosamine/N-Acetylmuramic acid kinase MurK from Clostridium acetobutylicum

MurK is a MurNAc- and GlcNAc-specific amino sugar kinase, phosphorylates MurNAc and GlcNAc at the 6-hydroxyl group in an ATP-dependent manner, and contributes to the recovery of both amino sugars during the cell wall turnover in Clostridium acetobutylicum. Herein, we determined the crystal structures of MurK in complex with MurNAc, GlcNAc, and glucose, respectively. MurK represents the V-shaped fold, which is divided into a small N-terminal domain and a large C-terminal domain. The catalytic pocket is located within the deep cavity between the two domains of the MurK monomer. We mapped the significant enzyme-substrate interactions, identified key residues involved in the catalytic activity of MurK, and found that residues Asp77 and Arg78 from the β4-α2-loop confer structural flexibilities to specifically accommodate GlcNAc and MurNAc, respectively. Moreover, structural comparison revealed that MurK adopts closed-active conformation induced by the N-acetyl moiety from GlcNAc/MurNAc, rather than closed-inactive conformation induced by glucose, to carry out its catalytic reaction. Taken together, our study provides structural and functional insights into the molecular mechanism of MurK for the phosphorylation of both MurNAc and GlcNAc, sugar substrate specificity, and conformational changes upon sugar substrate binding.

Contribution of Unsteadiness to Solid Fuel Burning Characteristics in a Scramjet Combustor

The contributions of unsteadiness to solid fuel combustion are investigated numerically and validated against new experiments in a deep cavity scramjet. Large-eddy simulations discretized with discontinuous Galerkin (DG) elements are solved with a flamelet manifold approach in three dimensions. A multiphase model that incorporated thermal decomposition inside the foam layer is coupled with stagnation flow flames to determine the combustion manifold and regression rate. The approach accurately models small-scale experiments of convective burning over solid fuel. The inclusion of the manifold into the DG code features two innovations: a polynomial fitting of the pressure to reduce the interpolation dimensions and the coefficient of determination to include non-monotonic manifolds in DG schemes. Model validation was performed using pressure and averaged regression rate data, both of which showed strong agreement with experiments. Three-dimensional pressure modes in the cavity support a substantial increase in regression rates and a broadening of the peak due to oscillations of the impingement point. The majority of fuel is pyrolyzed at the shear-layer reattachment point in a stagnation flow boundary layer. The fuel in the cavity is pyrolyzed by conductive heat transfer from the main shear layer. Poor combustion is observed in the expanding fuel section.

Surface Texturing of Silicon Wafers by Two-step Ag-assisted Etching Process with New NSR Solution

Abstract: Solar cells made of monocrystalline silicon can convert more solar energy into electrical energy if the cells can absorb greater amounts of light. Recently, it has been observed that metal-assisted catalyzed etching (MACE) is a good technology for manufacturing micro and nanostructures on silicon substrates. In this work, we use silver as a catalyst in a two-step metal-assisted etching process followed by a rebuilding nanostructure (NSR). We study the effect of changing the parameters of the second step in the MACE process (concentrations of etching solution materials, temperature, and reaction time), where black silicon was obtained with a reduced reflection of 3% without the NSR process. We tested the effect of two types of alkaline solutions in the NSR process on the surface structure of silicon. After performing an NSR operation with sodium hydroxide solution, the field emission scanning electron microscopy (FESEM) image shows a surface with upright pyramidal structures intertwined with deep cavities, and with a reflectance of 10.74%. However, after performing the NSR process with a solution of sodium silicate, the FESEM image shows a rough surface with non-overlapping pores of small cross-sections, achieving a reflectance of 8.65% within the wavelength range of 550-850nm. Keywords: Texturing, Monocrystalline silicon, Ag-assistance chemical etching, Black silicon, Reflectance.

Aeroacoustic Coupling in Rectangular Deep Cavities: Passive Control and Flow Dynamics

Deep cavity configurations are common in various industrial applications, including automotive windows, sunroofs, and many other applications in aerospace engineering. Flows over such a geometry can result in aeroacoustic coupling between the cavity shear layer oscillations and the surrounding acoustic modes. This phenomenon can result in a resonance that can lead to significant noise and may cause damage to mechanical structures. Flow control methods are usually used to reduce or eliminate the aeroacoustic resonance. An experimental set up was developed to study the effectiveness of both a cylinder and a profiled cylinder positioned upstream from the cavity in reducing the flow resonance. The cavity flow and the acoustic signals were obtained using particle image velocimetry (PIV) and unsteady pressure sensors, respectively. A decrease of up to 36 dB was obtained in the sound pressure levels (SPL) using the passive control methods. The profiled cylinder showed a similar efficacy in reducing the resonance despite the absence of a high-frequency forcing. Time-space cross-correlation maps along the cavity shear layer showed the suppression of the feedback mechanism for both control methods. A snapshot proper orthogonal decomposition (POD) showed interesting differences between the cylinder and profiled cylinder control methods in terms of kinetic energy content and the vortex dynamics behavior. Furthermore, the interaction of the wake of the control device with the cavity shear layer and its impact on the aeroacoustic coupling was investigated using the POD analysis.

Anticancer and antibacterial potential of green synthesized BSA conjugated silver nanoparticles

In this study, silver nanoparticles (AgNPs) were synthesized by utilizing different volumes of silver nitrate (AgNO3) and a medicinally important protein, bovine serum albumin (BSA); subsequently, their anticancer and antibacterial activities were investigated. The volume of AgNO3 and BSA were varied to obtain physically and chemically stable NPs for better therapeutic effects. The synthesized BSA@AgNPs were characterized by spectroscopic and microscopic methods, such as FTIR, and UV–Vis spectroscopy, SEM/EDS, and TEM/SAED. The characterization results offer substantial proof for the successful preparation of non-aggregated stable BSA@AgNPs. The EDS analysis revealed the presence of Ag, C, and O, thus reaffirming the preparation of BSA-conjugated AgNPs. The anticancer efficacy of BSA@AgNPs was studied against colorectal (HCT-116) and HeLa cancerous cell lines. The anticancer results showed that the treatment of cancer cells with BSA@AgNPs decreased the number of cells compared with untreated cells. The NPs prepared with a moderate amount of BSA showed a better inhibiting property than the particles prepared with a high amount of BSA. The antibacterial activity of BSA@AgNPs was studied against gram-positive (S. aureus) and gram-negative (E. coli) bacteria. SEM and TEM analyses confirmed that S. aureus and E. coli cells were damaged upon exposure to BSA@AgNPs in the form of deep pits and cavities as opposed to untreated cells. The obtained results show that the green synthesized BSA@AgNPs could be used as potential anticancer and antibacterial drugs.

A NOVEL TRAINING MODEL TO IMPROVE VASCULAR ANASTOMOSIS IN DEEP CAVITY WITH LIMITED ACCESS

Vascular surgery, particularly the anastomosis of blood vessels in deep cavities, poses significant challenges due to limited access and visibility. Traditional dental and surgical education often focuses on superficial techniques, leaving a gap in training for deep cavity procedures. This study introduces a new training model designed to address this gap and enhance skills in vascular surgery. Objective: To improve skills in performing vascular anastomosis in deep cavities, which presents greater difficulty compared to superficial areas, through the use of an improvised training model. Methods: This prospective observational study was conducted at the Combined Military Hospital, Rawalpindi, from 1st September 2023 to 29th February 2024. The improvised training model is box-shaped with a depth akin to the aorta, made of silicone rubber, and features a removable cap for easy cleaning and reuse. The model provides a realistic environment for practicing deep cavity vascular anastomosis. Participants, including experienced and novice surgeons, used the model to assess its effectiveness in enhancing surgical skills. Results: The model was highly effective in improving surgical techniques, with volunteer surgeons reporting an 82.9% enhancement in their skills and experiences. First-time users also noted significant improvements in their surgical competencies. Quantitative analysis showed that the model was perceived as cost-effective (71.4%) and reusable (74.3%). Participants commented on the realism of the model, particularly its depth and complexity, which facilitated repeated practice without the need for animals or cadavers. Conclusion: The study suggests that this improvised training model can significantly enhance skills in vascular anastomosis, particularly in deep cavity situations. The model is affordable, portable, durable, and provides a realistic simulation of aortic anastomosis in restricted spaces. Further studies are needed to validate its efficacy in broader contexts and its impact on patient outcomes.

Under the Influence of Water: Molecular Recognition of Organic Hydrophilic Molecules in Water with a Prismarene Host Driven by Hydration Effects.

A water-soluble prism[5]arene host can form endo-cavity complexes with hydrophilic organic substances in water by displacing frustrated water molecules from its deep cavity. Water molecules structured at both rims of the prismarene host can mediate hydrogen bonding interactions with the guest. Water-mediated hydrogen bonding interactions were invoked here to elucidate the elevated binding affinities and selectivity of the prismarene host toward hydrophilic organic guests. We show that water at the interface of a host-guest complex can act as an extension of the host structure, facilitating the accommodation of neutral guests within the binding site. This study highlights the crucial role of water in facilitating supramolecular interactions between a deep-cavity prismarene host and organic hydrophilic guests in aqueous medium.

Resonant standing surface waves excited by an oscillating cylinder in a narrow rectangular cavity

Resonant standing waves excited on the water surface in a deep narrow rectangular cavity by a fully immersed cylinder harmonically oscillating in the vertical direction are studied theoretically and experimentally. The effect of the finite wavemaker size is considered in the framework of the potential two-dimensional flow theory. Nonlinearities and weak dissipation at solid surfaces are accounted for. The spatio-temporal structure of the waves in the presence of detuning between the forcing and the natural frequency of the system is analysed. The variation of the surface shape in space and time studied in experiments supports the assumption of two-dimensional flow. The finite size of the wavemaker causes a downshift of the effective resonant frequency of the cavity; this effect is enhanced by the nonlinearity. For small amplitude waves, the surface elevation evolution in time is decomposed into the sum of the time-periodic function, corresponding to the forcing frequency, and its second harmonic; the shape of the wavenumber spectra of these components depends on the forcing frequency. For larger wave amplitudes, additional peaks in the frequency spectrum appear. The theoretical predictions are compared with the experimental results.

Flow dynamics and mixing of jet in crossflow with cylindrical cavity

The flow dynamics and mixing characteristics of an air jet issued from a cylindrical cavity in an air crossflow are numerically studied using a large-eddy-simulation technique. The cavity, aligned concentrically with the jet, is located beneath the crossflow wall. The jet-to-crossflow velocity ratio is 4, and the Reynolds number for the jet flow is 1.39×104 based on its diameter and centerline velocity. The presence of the cavity significantly influences the early evolution of the jet and its interaction with the crossflow. Complex vortical structures are observed. Notably, windward vortices on the jet surface increase in size, accompanied by a reduction in the Strouhal number. For a deep cavity, these vortices break down and result in small vortical tubes in the jet streamwise direction due to secondary instability. Also examined are leeward shear-layer vortices, hanging vortices, wake vortices, and the recirculating flow within the cavity. Their roles in the mixing between the jet fluid and the crossflow are identified. The cavity enhances mixing. The effect is significant in the near field but diminishes in the far field. By adjusting the cavity radius and depth, it is determined that the cavity depth exercises a more profound impact on jet evolution and mixing than the cavity radius. The most substantial influence occurs when a narrow and deep cavity is implemented. These findings may serve as guidelines for optimizing cavity design for effective modulation of jet behaviors.

Effect of Instrument Lubricant on Mechanical Properties of Restorative Composite.

Using a wetting resin or adhesive system as an instrument lubricant when placing composite layers is commonly practiced to improve handling. This study investigated whether instrument lubricants affected strength, stiffness, or hardness. Composite beams (TPH Spectra) were fabricated using a stainless steel mold (25×2.5×2 mm) in two steps, where the second half (12.5 mm) was added and cured against a cured first half (n=15). The composite surface at the open end of the first half was smoothed using an instrument lubricated with wetting resin (Ultradent) or universal adhesive (ScotchBond Universal), enough to prevent sticking, or without lubrication. An additional beam of each group was characterized using scanning electron microscopy. Monolithic specimens were also fabricated. After 24 hour storage (37°C, 100% humidity), the beams' flexural strength and stiffness were determined by four-point bending. Vickers surface hardness was measured on 24-hour composite samples in 2 mm deep acrylic cavities, cured after the surface was smoothed with the two instrument lubricants or no lubricant (n=10). Hardness was remeasured after finishing with a series of contouring and polishing discs. Data were statistically analyzed using ANOVA followed by Student-Newman-Keuls post hoc test at 0.05 significance level. There were significant differences (p<0.001) in flexural strength and stiffness among groups. While strength and stiffness were not affected by using a wetting resin as instrument lubricant, use of a universal adhesive increased strength and stiffness significantly, achieving monolithic values. Scanning electron micrographs showed less porosities at the interface when using instrument lubricants. Surface hardness was significantly reduced in groups in which instrument lubricants were used, but finishing/polishing restored original hardness (p<0.001). Lubricating an instrument with a wetting agent did not adversely affect physical or surface properties, provided the surface was finished and polished. If a universal adhesive was used as lubricant, the strength and stiffness of a layered composite could be increased, reaching monolithic values.

Effect of Fiber-Reinforced Composite Placement Site on Fracture Resistance of Premolar Teeth: An in vitro Study.

This study aimed to investigate the fracture behavior of upper premolars with deep MOD cavities that were restored with Ribbond resin-reinforced fibers (FRCs) placed in different orientations. A total of 54 extracted maxillary premolars were randomly divided into nine groups. The experimental groups underwent MOD cavity preparation with or without root canal treatment, followed by FRCs placed in the pulpal floor, proximal walls, or both. Fracture resistance was tested using an Instron Machine. The samples were visually inspected to analyze the fracture mode. The highest fracture resistance was observed in intact teeth (1299.98 ± 284.66 MPa). Placing Ribbond fibers in the pulpal floor (1155.86 ± 244.21 MPa) or the proximal walls (1077.56 ± 260.60 MPa) significantly improved fracture resistance (p= <0.05), compared to cavities restored with only resin composite (804.58 ± 93.34 MPa). However, placing Ribbond fibers in both the pulpal and proximal walls did not enhance fracture resistance. In the MOD-RCT groups, fracture resistance was improved only when Ribbond fibers were placed in the pulpal floor and the proximal walls. Fracture mode analysis revealed a combined fracture in most of the groups. This study concluded that using FRCs significantly improved the fracture resistance of MOD cavities in premolars and revealed that the placement site could be a determinant factor.

Bioorthogonal targeted cell membrane vesicles/cell-sheet composites reduce postoperative tumor recurrence and scar formation of melanoma

While surgical resection is the predominant clinical strategy in the treatment of melanoma, postoperative recurrence and undetectable metastasis are both pernicious drawbacks to this otherwise highly successful approach. Furthermore, the deep cavities result from tumor excision can leave long lasting wounds which are slow to heal and often leave visible scars. These unmet needs are addressed in the present work through the use of a multidimensional strategy, and also promotes wound healing and scar reduction. In the first phase, cell membrane-derived nanovesicles (NVs) are engineered to show PD-1 and dibenzocyclooctyne (DBCO). These are capable of reactivating T cells by blocking the PD-1/PD-L1 pathway. In the second phase, azido (N3) labeled mesenchymal stem cells (MSCs) are cultured into cell sheets using tissue engineering, then apply directly to surgical wounds to enhance tissue repair. Owing to the complementary association between DBCO and N3 groups, PD-1 NVs were accumulated at the site of excision. This strategy can inhibit postoperative tumor recurrence and metastasis, whilst also promoting wound healing and reducing scar formation. The results of this study set a precedent for a new and innovative multidimensional therapeutic strategy in the postoperative treatment of melanoma.

Biologically inspired nanoformulations for the control of bacterial canker pathogens Clavibacter michiganensis subsp. michiganensis and subsp. capsici

Clavibacter michiganensis subsp. michiganensis (Cmm) and C. michiganensis subsp. capsici (Cmc) are phytopathogenic bacteria that cause bacterial canker disease in tomatoes and peppers, respectively. Bacterial canker disease poses serious challenges to solanaceous crops, causing significant yield losses and economic costs. Effective management necessitates the development of sustainable control strategies employing nanobiotechnology. In this study, the antibacterial effects of four Aspergillus sojae-mediated nanoformulations, including cobalt oxide nanoparticles (Co3O4 NPs), zinc oxide nanoparticles (ZnO NPs), cobalt ferrite nanoparticles (CoFe2O4 NPs), and CoFe2O4/functionalized multi-walled carbon nanotube (fMWCNT) bionanocomposite, were evaluated against Cmm and Cmc. The diameters of the zone of inhibition of A. sojae-mediated Co3O4 NPs, ZnO NPs, CoFe2O4 NPs, and CoFe2O4/fMWCNT bionanocomposite against Cmm and Cmc were 23.60 mm, 22.09 mm, 27.65 mm, 22.51 mm, and 19.33 mm, 17.66 mm, 21.64 mm, 18.77 mm, respectively. The broth microdilution assay was conducted to determine the minimal inhibitory and bactericidal concentrations. The MICs of Co3O4 NPs, ZnO NPs, CoFe2O4 NPs, and CoFe2O4/fMWCNT bionanocomposite against Cmm were 2.50 mg/mL, 1.25 mg/mL, 2.50 mg/mL, and 2.50 mg/mL, respectively. While, their respective MBCs against Cmm were 5.00 mg/mL, 2.50 mg/mL, 5.00 mg/mL, and 5.00 mg/mL. The respective MICs of Co3O4 NPs, ZnO NPs, CoFe2O4 NPs, and CoFe2O4/fMWCNT bionanocomposite against Cmc were 2.50 mg/mL, 1.25 mg/mL, 5.00 mg/mL, and 5.00 mg/mL. While, their respective MBCs against Cmc were 5.00 mg/mL, 2.50 mg/mL, 10.00 mg/mL, and 10.00 mg/mL. The morphological and ultrastructural changes of Cmm and Cmc cells were observed using field-emission scanning and transmission electron microscopy before and after treatment with sub-minimal inhibitory concentrations of the nanoformulations. Nanoformulation-treated bacterial cells became deformed and disrupted, displaying pits, deep cavities, and groove-like structures. The cell membrane detached from the bacterial cell wall, electron-dense particles accumulated in the cytoplasm, cellular components disintegrated, and the cells were lysed. Direct physical interactions between the prepared nanoformulations with Cmm and Cmc cells might be the major mechanism for their antibacterial potency. Further research is required for the in vivo application of the mycosynthesized nanoformulations as countermeasures to combat bacterial phytopathogens.

A self-powered, anti-bacterial, moist-wound dressing made with electroactive free-flowing hydrogel particles, encourage faster wound closure

Chronic exuding wounds continue to present a significant healthcare challenge, with prolonged healing times and an increased risk of complications. The wounds with their complex contours and hard-to-reach areas, can particularly benefit from the advantages offered by free-flowing hydrogel particles. Innovative approaches are needed to enhance the healing process and improve outcomes in wound care. Building upon previous research on piezo-driven electrical stimulation, herein, we introduce self-powered, silver nanoparticles containing electroactive hydrogel particles as an innovative wound dressing specifically designed to fill deep irregular wound cavities. Apart from providing anti-bacterial and a moist wound environment, the hydrogel particles provide electrical stimulation to the wound-bed. The self-powered dressing eliminates the need for an external power source by harnessing the electrical activity from a piezo-responsive polyvinylidene fluoride (PVDF) membrane, thereby improving patient compliance. The electroactive hydrogel particles exhibited improved cellular responses including cell migration, proliferation and angiogenesis. Accelerated wound closure, increase in collagen synthesis and improvement in angiogenesis was observed in rats treated with the dressing. By elucidating the mechanisms and benefits of this innovative approach, we seek to highlight its potential as an effective and practical solution for the treatment of challenging wounds.

Technological simulation of the process of hot forging of two-layer forgings with deep cavities and an inverted cone

Technological simulation of the process of hot forging of two-layer forgings with deep cavities and an inverted cone