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International Journal of Surgery Case... Jun 2024This case report describes the successful use of a latissimus dorsi muscle flap attached to the femoral vessels to cover a large mass loss in a 27-year-old woman with...
INTRODUCTION AND IMPORTANCE
This case report describes the successful use of a latissimus dorsi muscle flap attached to the femoral vessels to cover a large mass loss in a 27-year-old woman with bladder exstrophy. The two-stage reconstruction showed excellent results six months after surgery.
CASE PRESENTATION
A 27-year-old woman with bladder exstrophy and previous enterocystoplasty with Mitrofanoff-type urinary diversion combined with a late fascial flap presented 10 years later with disembowelment near the pubic symphysis. A two-stage reconstruction using a latissimus dorsi flap and polypropylene mesh was performed with excellent aesthetic and functional results.
CLINICAL DISCUSSION
The latissimus dorsi muscle flap, described by J.M. Servant in 1984 as the "apple turnover" technique, is highly reliable for reconstructing large substance losses with minimal functional sequelae. The procedure in this case resulted in very satisfactory aesthetic and functional results at six months postoperatively. This approach provided a safe and effective technique of last resort.
CONCLUSION
the two-stage latissimus dorsi flap technique was a reliable, safe and effective solution for this complex reconstructive challenge.
PubMed: 38917698
DOI: 10.1016/j.ijscr.2024.109939 -
Indian Journal of Ophthalmology Jul 2024The aim of this study is to describe a modified technique for internal refixation of dislocated scleral-sutured polymethylmethacrylate (PMMA) intraocular lenses (IOLs)...
The aim of this study is to describe a modified technique for internal refixation of dislocated scleral-sutured polymethylmethacrylate (PMMA) intraocular lenses (IOLs) with eyelets. Three-port pars plana vitrectomy was performed. Through the scleral fixation site, a 30-gauge needle loaded with an 8-0 polypropylene suture was inserted into the vitreous cavity. The suture end was passed through the eyelet of IOL with 25-gauge forceps. Next, it was guided out of the eye through the original scleral fixation point. The end of the exterior suture was buried with a flapless intrascleral knotting technique. Six eyes of six patients were successfully treated with this technique and followed up for 6-12 months postsurgery. In all cases, there was significant improvement in uncorrected visual acuity. IOLs were stable with proper centration and no major complications. This modified technique offers an effective and minimally invasive surgical alternative for refixation of dislocated scleral-sutured PMMA IOLs with eyelets.
Topics: Humans; Polymethyl Methacrylate; Male; Visual Acuity; Lenses, Intraocular; Female; Reoperation; Suture Techniques; Vitrectomy; Middle Aged; Sclera; Artificial Lens Implant Migration; Follow-Up Studies; Aged; Sutures; Adult
PubMed: 38905465
DOI: 10.4103/IJO.IJO_2809_23 -
ACS Applied Polymer Materials Jun 2024Food smart packaging has emerged as a promising technology to address consumer concerns regarding food conservation and food safety. In this context, we report the...
Food smart packaging has emerged as a promising technology to address consumer concerns regarding food conservation and food safety. In this context, we report the rational design of azide-containing pyranoflavylium-based pH-sensitive dye for subsequent click chemistry conjugation toward a chitosan-modified alkyne. The chitosan-pyranoflavylium conjugate was characterized by infrared (ATR-FTIR), ultraviolet-visible (UV-vis), nuclear magnetic resonance (NMR) spectroscopies, and dynamic light scattering (DLS), as well as its thermodynamic parameters related to their pH-dependent chromatic features. The fabrication of thin-films through electrostatic-driven layer-by-layer (LbL) assembly technology was first screened by quartz crystal microbalance with dissipation monitoring (QCM-D) onto gold substrates, and then free-standing (FS) multilayered membranes from polypropylene substrate were obtained using a homemade automatic dipping robot. The membranes' characterization included morphology analysis and thickness evaluation, assessed by scanning electron microscopy (SEM), pH-responsive color change performance tests using buffer solutions at different pH levels, and biogenic amines-enriched model solutions, demonstrating the feasibility and effectiveness of the chitosan-pyranoflavylium/alginate biomembranes for food spoilage monitoring. This work provides insights toward the development of innovative pH-responsive smart biomaterials for advanced and sustainable technological packaging solutions, which could significantly contribute to ensuring food safety and quality, while reducing food waste.
PubMed: 38903401
DOI: 10.1021/acsapm.4c01085 -
ACS Applied Polymer Materials Jun 2024The processing of an immiscible polymer blend using melt blending (i.e., extrusion) often results in a polymer material with inferior mechanical performance compared...
The processing of an immiscible polymer blend using melt blending (i.e., extrusion) often results in a polymer material with inferior mechanical performance compared with its virgin counterparts. Here, we report and compare the properties of immiscible polymer blends produced from industrial mixed plastic waste from shredder residue comprising at least four different polymers (acrylonitrile butadiene styrene, polystyrene, polypropylene, and polyethylene) and a prior melt-blending step employed. As anticipated, mixed plastic blend produced a prior melt-blending step exhibited a more homogeneous microstructure, resulting in brittleness, poor work of fracture, and single-edge notched fracture toughness with a flat R-curve. Without the intimate polymers mixing arising from melt blending, the resulting mixed plastic blend was found to possess a more heterogeneous concentric ellipsoid microstructure with large single polymer domains. This mixed plastic blend demonstrated progressive failure under uniaxial tensile loading, along with a more ductile single-edge notched fracture toughness response accompanied by a growing R-curve. Digital image correlation and fractographic analysis revealed that melt blending created a large number of incompatible polymer boundaries that acted as stress concentration points, leading to brittleness and earlier onset catastrophic failure. The more heterogeneous mixed plastic blend produced using a prior melt-blending step contains a smaller number of incompatible polymer boundaries. Additionally, the presence of larger single polymer domains also implies that the mechanical characteristics of the single polymer can be exploited in the immiscible mixed plastic blend. Our work opens up a simple pathway to add value to mixed plastic waste from shredder residue for use in engineering applications, diverting them away from landfill or incineration.
PubMed: 38903398
DOI: 10.1021/acsapm.4c00360 -
Microplastics alter soil structural stability as quantified by high-energy moisture characteristics.Journal of Hazardous Materials Jun 2024Microplastics (MiPs) can potentially influence soil structural stability, with impacts likely dependent on their chemistry, concentration, size, and degradation in soil....
Microplastics (MiPs) can potentially influence soil structural stability, with impacts likely dependent on their chemistry, concentration, size, and degradation in soil. This study used high-energy moisture characteristics (HEMC; water retention at matric suctions from 0 to 50 hPa) to quantify the effects of these MiP properties on soil structure stabiltiy. The HEMCs of soil samples contaminated with polypropylene (PP) or polyethylene (PE) were measured and modelled. Greater MiP concentrations (2 % and 7 % w w) increased the volume of drainable pores (VDP). At smaller MiP concentrations (0.5 % and 1 % w w), larger MiP fibres (3 and 5 mm) exhibited higher VDP values compared to a smaller size (1.6 mm) across a range of concentrations. Both PE and PP MiPs increased the modal matric suction (h). The impacts on VDP and h were more pronounced for fast than slow wetting, likely due to MiPs fibres entangling around soil aggregates, and MiPs pores filling after aggregate slaking, respectively. Soil structural index (SI) and stability ratio (SR) values increased following MiP incorporation. Our findings revealed the detrimental impacts of MiPs on soil aggregates and pores, demonstrating that MiPs significantly influence HEMC parameters due to combined impacts on structure stability and pore distribution. ENVIRONMENTAL IMPLICATION: Microplastics have emerged as a major anthropogenic hazardous material in the soil environment, with secondary impacts on soil structure and aggregate stability. Our study indicates that MiPs alter water retention, pore distribution, and soil hydraulic properties, affecting soil's ability to retain and supply water. The introduction of MiPs leads to the destruction of soil aggregates and pores, compromising soil health and productivity. By characterising structural stability and pore structure dynamics using HEMC, this study highlights the sensitivity of MiP impacts, emphasizing the need for comprehensive assessment and strategies to preserve soil ecosystem functioning in the face of increasing MiP pollution.
PubMed: 38901260
DOI: 10.1016/j.jhazmat.2024.134940 -
Journal of Hazardous Materials Jun 2024Parabens are emerging contaminants that have been detected in drinking water. Their presence in DW distribution systems (DWDS) can alter bacterial behaviour,...
Parabens are emerging contaminants that have been detected in drinking water. Their presence in DW distribution systems (DWDS) can alter bacterial behaviour, characteristics, and structure, which may compromise DW disinfection. This work provides insights into the impact of methylparaben (MP) on the tolerance to chlorine disinfection and antibiotics from dual-species biofilms formed by Acinetobacter calcoaceticus and Stenotrophomonas maltophilia isolated from DW and grown on high-density polyethylene (HDPE) and polypropylene (PPL). Results showed that dual-species biofilms grown on PPL were more tolerant to chlorine disinfection, expressing a decrease of over 50 % in logarithmic reduction values of culturable cells in relation to non-exposed biofilms. However, bacterial tolerance to antibiotics was not affected by MP presence. Although MP-exposed dual-species biofilms grown on HDPE and PPL were metabolically more active than non-exposed counterparts, HDPE seems to be the material with lower impact on DW risk management and disinfection, if MP is present. Overall, results suggest that MP presence in DW may compromise chlorine disinfection, and consequently affect DW quality and stability, raising potential public health issues.
PubMed: 38897118
DOI: 10.1016/j.jhazmat.2024.134883 -
Sensors (Basel, Switzerland) May 2024In order to solve the problem of flexible sliding tactile composite sensing in the actual grasp of intelligent robot fingers, this paper proposes a research on a convex...
In order to solve the problem of flexible sliding tactile composite sensing in the actual grasp of intelligent robot fingers, this paper proposes a research on a convex fiber grating tactile sliding sensor based on mechanical fingers. Based on the sensing principle of fiber Bragg grating, 3D printing technology was used to encapsulate the FBG sensor array with elastic 50 A resin, a double-layer "hemispherical cuboid" distributed sensing unit was designed, and the FBG slippery tactile sensor was actually pasted on the surface of the mechanical finger for static and dynamic experiments. The experimental results show that the slippery tactile sensor designed in this paper has a good linear relationship with temperature and strain. The temperature sensitivities of the polymer-packaged FBGs are KT1 = 13.04 pm/°C and KT2 = 12.91 pm/°C, and they have a pressure sensitivity of 40.4 pm/N and 31.2 pm/N, respectively. The FBG sliding tactile sensor not only realizes the identification of the sliding signal generation point and the end point but also completes the classification and identification of sandpaper, cardboard, and polypropylene plastic, and it has a high degree of fit with the robot finger, which has certain application value for the intelligent robot sliding tactile signal perception.
PubMed: 38894165
DOI: 10.3390/s24113374 -
Materials (Basel, Switzerland) Jun 2024This study addresses the structure-property relationship within the green concept of wood fibres with cellulose nanofibre functionalised composites (nW-PPr) containing...
This study addresses the structure-property relationship within the green concept of wood fibres with cellulose nanofibre functionalised composites (nW-PPr) containing recycled plastic polyolefins, in particular, polypropylene (PP-r). It focuses especially on the challenges posed by nanoscience in relation to wood fibres (WF) and explores possible changes in the thermal properties, crystallinity, morphology, and mechanical properties. In a two-step methodology, wood fibres (50% wt%) were first functionalised with nanocellulose (nC; 1-9 wt%) and then, secondly, processed into composites using an extrusion process. The surface modification of nC improves its compatibility with the polymer matrix, resulting in improved adhesion, mechanical properties, and inherent biodegradability. The effects of the functionalised WF on the recycled polymer composites were investigated systematically and included analyses of the structure, crystallisation, morphology, and surface properties, as well as thermal and mechanical properties. Using a comprehensive range of techniques, including X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), zeta potential measurements, and dynamic mechanical analysis (DMA), this study aims to unravel the intricate interplay of factors affecting the performance and properties of the developed nanocellulose-functionalised wood fibre-polymer composites. The interfacial adhesion of the nW-PPr polymer composites, crystallisation process, and surface properties was improved due to the formation of an H-bond between the nW coupling agent and neat PP-r. In addition, the role of nW (1.0 wt%) as a nucleating agent resulted in increased crystallinity, or, on the other hand, promoted the interfacial interaction with the highest amount (3.0% wt%, 9.0% wt%) of nW in the PP-r preferentially between the nW and neat PP-r, and also postponed the crystallisation temperature. The changes in the isoelectric point of the nW-PPr polymer composites compared to the neat PP-r polymer indicate the acid content of the polymer composite and, consequently, the final surface morphology. Finally, the higher storage modulus of the composites compared to neat r-PP shows a dependence on improved crystallinity, morphology, and adhesion. It was clear that the results of this study contribute to a better understanding of sustainable materials and can drive the development of environmentally friendly composites applied in packaging.
PubMed: 38894002
DOI: 10.3390/ma17112739 -
Materials (Basel, Switzerland) Jun 2024The COVID-19 pandemic has underscored the critical need for effective air filtration systems in healthcare environments to mitigate the spread of viral and bacterial...
The COVID-19 pandemic has underscored the critical need for effective air filtration systems in healthcare environments to mitigate the spread of viral and bacterial pathogens. This study explores the utilization of copper nanoparticle-coated materials for air filtration, offering both antiviral and antimicrobial properties. Highly uniform spherical copper oxide nanoparticles (~10 nm) were synthesized via a spinning disc reactor and subsequently functionalized with carboxylated ligands to ensure colloidal stability in aqueous solutions. The functionalized copper oxide nanoparticles were applied as antipathogenic coatings on extruded polyethylene and melt-blown polypropylene fibers to assess their efficacy in air filtration applications. Notably, Type IIR medical facemasks incorporating the copper nanoparticle-coated polyethylene fibers demonstrated a >90% reduction in influenza virus and SARS-CoV-2 within 2 h of exposure. Similarly, heating, ventilation, and air conditioning (HVAC) filtration pre- (polyester) and post (polypropylene)-filtration media were functionalised with the copper nanoparticles and exhibited a 99% reduction in various viral and bacterial strains, including SARS-CoV-2, , , , and . In both cases, this mitigates not only the immediate threat from these pathogens but also the risk of biofouling and secondary risk factors. The assessment of leaching properties confirmed that the copper nanoparticle coatings remained intact on the polymeric fiber surfaces without releasing nanoparticles into the solution or airflow. These findings highlight the potential of nanoparticle-coated materials in developing biocompatible and environmentally friendly air filtration systems for healthcare settings, crucial in combating current and future pandemic threats.
PubMed: 38893928
DOI: 10.3390/ma17112664 -
Materials (Basel, Switzerland) May 2024As an important part of head protection equipment, research on the material and structural application of helmet liners has always been one of the hotspots in the field... (Review)
Review
As an important part of head protection equipment, research on the material and structural application of helmet liners has always been one of the hotspots in the field of helmets. This paper first discusses common helmet liner materials, including traditional polystyrene, polyethylene, polypropylene, etc., as well as newly emerging anisotropic materials, polymer nanocomposites, etc. Secondly, the design concept of the helmet liner structure is discussed, including the use of a multi-layer structure, the addition of geometric irregular bubbles to enhance the energy absorption effect, and the introduction of new manufacturing processes, such as additive manufacturing technology, to realize the preparation of complex structures. Then, the application of biomimetic structures to helmet liner design is analyzed, such as the design of helmet liner structures with more energy absorption properties based on biological tissue structures. On this basis, we propose extending the concept of bionic structural design to the fusion of plant stalks and animal skeletal structures, and combining additive manufacturing technology to significantly reduce energy loss during elastic yield energy absorption, thus developing a reusable helmet that provides a research direction for future helmet liner materials and structural applications.
PubMed: 38893913
DOI: 10.3390/ma17112649