A Systematic Review Examining the Experimental Methodology Behind In Vivo Testing of Hiatus Hernia and Diaphragmatic Hernia Mesh

Introduction Mesh implants are regularly used to help repair both hiatus hernias (HH) and diaphragmatic hernias (DH). In vivo studies are used to test not only mesh safety, but increasingly comparative efficacy. Our work examines the field of in vivo mesh testing for HH and DH models to establish current practices and standards. Method This systematic review was registered with PROSPERO. Medline and Embase databases were searched for relevant in vivo studies. Forty-four articles were identified and underwent abstract review, where 22 were excluded. Four further studies were excluded after full-text review—leaving 18 to undergo data extraction. Results Of 18 studies identified, 9 used an in vivo HH model and 9 a DH model. Five studies undertook mechanical testing on tissue samples—all uniaxial in nature. Testing strip widths ranged from 1–20 mm (median 3 mm). Testing speeds varied from 1.5–60 mm/minute. Upon histology, the most commonly assessed structural and cellular factors were neovascularisation and macrophages respectively (n = 9 each). Structural analysis was mostly qualitative, where cellular analysis was equally likely to be quantitative. Eleven studies assessed adhesion formation, of which 8 used one of four scoring systems. Eight studies measured mesh shrinkage. Discussion In vivo studies assessing mesh for HH and DH repair are uncommon. Within this relatively young field, we encourage surgical and materials testing institutions to discuss its standardisation.

A Mini-review: Silver Nanoparticles (AgNPs) as Antimicrobial in Magical Socks

Silver nanoparticles vary in size from 1 to 100 nm. These have unique properties that assists in molecular diagnostics, therapies, and devices used in many medical procedures. The most popular methods for making silver nanoparticles are physical and chemical approaches. Chemical and physical methods are troublesome because synthesis is expensive. The biological approach is a feasible alternative one. The major biological processes involved are bacteria, fungi, and plant extracts. Silver nanoparticles are mainly used in diagnostic and therapeutic applications in medicine. Their medical uses rely on the antimicrobial property, while the anti-inflammatory property has its own range of applications. Silver nanoparticles are used in a number of medical therapies and instruments, as well as in a variety of biological sciences. This article focuses on chemical and biological techniques for synthesizing AgNPs, which will subsequently be utilized to coat socks materials, testing antimicrobial activity and comparing the ability of these coated fabrics to minimize infections.

Anterior Glenoid Reconstruction With Distal Tibial Allograft: Biomechanical Impact of Fixation and Presence of a Retained Lateral Cortex

Background: Glenoid reconstruction with distal tibial allograft (DTA) is a known surgical option for treating recurrent glenohumeral instability with anterior glenoid bone loss; however, biomechanical analysis has yet to determine how graft variability and fixation options alter the torque of screw insertion and load to failure. Hypothesis: It was hypothesized that retention of the lateral cortex of the DTA graft and the presence of a washer with the screw will significantly increase the maximum screw placement torque as well as the load to failure. Study Design: Controlled laboratory study. Methods: Whole, fresh distal tibias were used to harvest 28 DTA grafts, half of which had the lateral cortex removed and half of which had the lateral cortex intact. The grafts were secured to polyurethane solid foam blocks with a 2-mm epoxy laminate to simulate a glenoid with an intact posterior glenoid cortex. Grafts underwent fixation with 4.0-mm cannulated drills, and screws and washers were used for half of each group of grafts while screws alone were used for the other half, creating 4 equal groups of 7 samples each. A digital torque-measuring screwdriver recorded peak torque for screw insertion. Constructs were then tested in compression with a uniaxial materials testing system and loaded in displacement control at 100 mm/min until at least 3 mm of displacement occurred. Ultimate load was defined as the load sustained at clinical failure. Results: The use of a washer significantly improved the ultimate torque that could be applied to the screws (+cortex and +washer = 12.42 N·m [SE, 0.82]; –cortex and +washer = 10.54 N·m [SE, 0.59]) ( P < .0001), whereas the presence of the native bone cortex did not have a significant effect (+cortex and –washer = 7.83 N·m [SE, 0.40]; –cortex and –washer = 8.03 N·m [SE, 0.56]) ( P = .181). Conclusion: In a hybrid construct of fresh cadaveric DTA grafts secured to a foam block glenoid model, the addition of washers was more effective than the retention of the lateral distal tibial cortex for both load to failure and peak torque during screw insertion. Clinical Relevance: This biomechanical study is relevant to the surgeon when choosing a graft and selecting fixation options during glenoid reconstruction with a DTA graft.

Virtual reality as a tool for training specialists in the field of radiation non-destructive testing

Organizational, technical and methodological approaches to the creation and application of virtual reality in additional education are considered. Particularly for use and development of a digital radiography simulator in non-destructive testing of products and materials. It is noted that virtual reality technologies are most widely used in training and knowledge testing of engineering and technical personnel and workers in production, as well as in technological preparation during complex and exacting operations, including products and materials testing. The pilot solutions obtained and tested to date allow us to evaluate the results of complex scientific research. The prospects of expanding the applicability range of software and hardware virtual reality solutions, including those based on network interfaces, protocols and telecommunications solutions, are determined.

Destructive and non-destructive testing of samples from PLA and PETG materials

This study deals with the properties of PLA and PETG materials, which are important for gaining knowledge in biomedical applications. The process of obtaining an ideal implant from a material with suitable mechanical and physical properties is a complex process considered to be one of the most difficult in tissue engineering. PLA and PETG material properties were determined based on performed non-destructive and destructive materials testing methods. Destructive testing was performed on Hegewald and Peschke equipment and non-destructive testing was performed on Carl Zeiss Metrotome 1500 (Germany). Commercial filaments from various companies were selected, from which type 5A dogbone samples were printed on a TRILAB printer. Subsequently, after carrying out the tests on dogbone samples, the results were evaluated and compared with the help of graphs and tables.

Knots Tied With High–Tensile Strength Tape Biomechanically Outperform Knots Tied With Round Suture

Background: Tape-type suture material is well-accepted in arthroscopy surgery. Purpose: To compare the knot security of a high–tensile strength round suture and high–tensile strength tape with commonly used arthroscopic knots. Study Design: Controlled laboratory study. Methods: We compared the performance of No. 2 braided nonabsorbable high-strength suture with that of 1.3-mm braided nonabsorbable high-strength tape. Five commonly used arthroscopic knots were investigated: the Roeder knot; the Western knot; the Samsung Medical Center (SMC) knot; the Tennessee knot; and a static surgeon’s knot. Seven knots were tied for each combination of knots and suture types. Knots were tied on a 30-mm circumferential metal post, and the suture loops were transferred to a materials testing machine. After preloading to 5 N, all specimens were loaded to failure. The clinical failure load, defined as the maximal force to failure at 3 mm of crosshead displacement, yield load, and stiffness, were recorded. A 2-way analysis of variance was used to determine differences between the groups. Results: Both suture type and knot type significantly affected the clinical failure load, yield load, and stiffness ( P = .002). The high-strength tape resulted in a significantly greater clinical failure load than the high-strength suture in the case of the Roeder knot, Western knot, and SMC knot ( P = .027, .005, and .016, respectively). When the high-strength round suture was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the Tennessee knot ( P = .011, .003, and .035, respectively) and the static surgeon’s knot ( P < .001 for all). When the high-strength tape was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the static surgeon’s knot ( P = .001, .001, and .003, respectively). Conclusion: The results of this study indicated that arthroscopic knots tied using 1.3-mm high-strength tape biomechanically outperformed knots tied using a No. 2 high-strength suture. While the static surgeon’s knot exhibited the best biomechanical properties, the Tennessee knot resulted in generally better biomechanical properties among the arthroscopic sliding knots. Clinical Relevance: Elongation and loosening of tied knots possibly affects the clinical results of repaired constructs.

A Novel Animal Model for Three-Dimensional Horizontal and Vertical Bone Regeneration Using Osseous Shell Technique: A Pre-clinical In-Vivo Study in Rabbits

Background: Bone grafting is commonly used for reconstructing skeletal defects in the craniofacial region. Several bone augmentation models were developed to optimize bone regeneration in both vertical and horizontal dimesions. Aim: The aim of this study was to develop a surgical animal model for establishing a three-dimensional (3D) grafting environment in the animal's mandibular ramus for horizontal and vertical bone regeneration using osseous shell technique, as in human patients. Materials and methods: Initial osteological and imaging survey were performed on a postmortem skull of a New Zealand White (NZW) rabbit skull, Oryctolagus cuniculus, for feasibility assessment for performing the surgical procedure. 3D osseus defect was created in the mandibular ramus through a submandibular incision and the osseous shell plates were stabilized with osteosynthesis fixation screws and defect filled with particular bone grafting material. The in-vivo surgical procedures were conducted in four 8-week-old NZW rabbits utilising two osseous shell materials: xenogenic human cortical plates, and autogenous rabbit cortical plates, and the created 3D defects were filled using xenograft and allograft bone grafting materials. The healed defects were evaluated for bone regeneration after 12 weeks using histological and Cone Beam Computed Tomography (CBCT) imaging analysis. Results: Clinical analysis at 12 weeks after surgery revealed the stability of the 3D grafted bone augmentation defects using the osseous shell technique. Imaging and histological analyses confirmed the effectiveness of this model in assessing bone regeneration. Conclusion: The rabbit model is an efficient and reliable biological method for creating a seizable three-dimensional horizontal and vertical bone regeneration model in the mandibular ramus using osseous shell technique for testing various bone-substitute materials testing without compromising the health of the animal. The filled defects could be analyzed for osteogenesis, quantification of bone formation, and healing potential, using histomorphometric analysis, in addition to 3D morphologic evaluation using radiation imaging.

PRELIMINARY EXPERIMENTAL/ANALYTICAL CORRELATIONS OF THE FORMING OF STRETCH BROKEN CARBON FIBER TOWS AND LAMINATES

Stretch broken carbon fiber (SBCF) is generated by breaking individual filaments in carbon fiber tows at inherent flaws in tension in a continuous process. This process results in randomly broken, collimated fiber fragments. The shorter fiber length improves forming properties while retaining mechanical strength through shear load transfer. SBCF has the potential to take advantage of low-cost manufacturing processes like those used in sheet metal forming, resulting in ordersof- magnitude cost savings and enabling conversion to composite structures across the industry. Because uncured continuous carbon fiber composites do not exhibit significant plastic deformation, they cannot be readily adapted to many common sheet metal forming techniques. SBCF composites exhibit pseudo-plastic deformation, but this deformation is due to different mechanisms. To adapt the manufacturing processes for large and complex parts, new materials testing techniques are needed to quantify the forming behavior of SBCF at the meso-scale (tow and ply). This work’s primary objective is to develop predictive models for complex shape forming and large component characterization. Tests have been developed to characterize the behavior of SBCF tows under various forming conditions. Tow forming and laminate bulge testing allowed for experimental characterization of the SBCF response. Respectively, these tests focus on developing the load-displacement material response along with variation of the strain distribution. Using design of experiment (DOE) technique, the forming response to materials properties such as resin viscosity and mean fiber length have been related. For each test, a correlated Finite Element Analysis (FEA) model was developed, allowing for progression toward understanding a wider array of properties than experimentally.

Current Trends in Integration of Nondestructive Testing Methods for Engineered Materials Testing

Material failure may occur in a variety of situations dependent on stress conditions, temperature, and internal or external load conditions. Many of the latest engineered materials combine several material types i.e., metals, carbon, glass, resins, adhesives, heterogeneous and nanomaterials (organic/inorganic) to produce multilayered, multifaceted structures that may fail in ductile, brittle, or both cases. Mechanical testing is a standard and basic component of any design and fabricating process. Mechanical testing also plays a vital role in maintaining cost-effectiveness in innovative advancement and predominance. Destructive tests include tensile testing, chemical analysis, hardness testing, fatigue testing, creep testing, shear testing, impact testing, stress rapture testing, fastener testing, residual stress measurement, and XRD. These tests can damage the molecular arrangement and even the microstructure of engineered materials. Nondestructive testing methods evaluate component/material/object quality without damaging the sample integrity. This review outlines advanced nondestructive techniques and explains predominantly used nondestructive techniques with respect to their applications, limitations, and advantages. The literature was further analyzed regarding experimental developments, data acquisition systems, and technologically upgraded accessory components. Additionally, the various combinations of methods applied for several types of material defects are reported. The ultimate goal of this review paper is to explain advanced nondestructive testing (NDT) techniques/tests, which are comprised of notable research work reporting evolved affordable systems with fast, precise, and repeatable systems with high accuracy for both experimental and data acquisition techniques. Furthermore, these advanced NDT approaches were assessed for their potential implementation at the industrial level for faster, more accurate, and secure operations.