Investigation of the deformation and strength characteristics of the thread connection in the manufacture of products from fur waste

By the method of mathematical planning of the experiment, regression equations were obtained for the breaking load and the breaking relative elongation of the thread connection of a special furrier’s seam in the manufacture of products from fur waste. As input factors were taken: the number of stitches in 1 cm., Thread thickness, needle diameter. The features of the behavior of the strength model of this thread connection are revealed.

Study of the Filtration Performance of Multilayer and Multiscale Fibrous Structures

As the incidence of small-diameter particles in the air has increased in recent decades, the development of efficient filtration systems is both urgent and necessary. Nanotechnology, more precisely, electrospun nanofibres, has been identified as a potential solution for this issue, since it allows for the production of membranes with high rates of fibres per unit area, increasing the probability of nanoparticle collision and consequent retention. In the present study, the electrospinning technique of polyamide nanofibre production was optimized with the variation of parameters such as polymer concentration, flow rate and needle diameter. The optimized polyamide nanofibres were combined with polypropylene and polyester microfibres to construct a multilayer and multiscale system with an increased filtration efficiency. We observed that the penetration value of the multilayer system with a PA membrane in the composition, produced for 20 min in the electrospinning, is 2.7 times smaller than the penetration value of the system with the absence of micro and nano fibers.

Synthesis of titania fibers by electrospinning and its photocatalytic degradation properties

The electrospinning precursor solution was prepared by dissolving polyvinyl pyrrolidone as template, tetrabutyl titanate as titanium source, and acetic acid as inhibitor. The TiO2 nanofilms were prepared by precursor solution electrospinning and subsequent calcination. Thermal gravimetric analysis (TG), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize and analyze the samples. The influence of technological parameters on spinning fiber morphology was also studied. The results indicate that the TiO2 nanofibers morphology is good when the parameters are as follows: voltage 1.4×104 V，spinning distance 0.2 m，translational velocity 2.5×10-3 m·s-1, flow rate 3×10-4 m·s-1, and needle diameter 3×10-4 m. The diameter of the fibers is about 150 nm. With the 1×10-4 mol·L-1 methylene blue solution used as simulated degradation target, the degradation rate is 95.8% after 180 minutes.

Acute Cartilage Injury Induced by Trans-Articular Sutures

Objective To determine the extent of acute cartilage injury by using trans-articular sutures. Methods Five different absorbable sutures, monofilament polydioxanone (PDS) and braided polyglactin (Vicryl), were compared on viable human osteochondral explants. An atraumatic needle with 30 cm of thread was advanced through the cartilage with the final thread left in the tissue. A representative 300 μm transversal slice from the cartilage midportion was stained with Live/Dead probes, scanned under the confocal laser microscope, and analyzed for the diameters of (a) central “Black zone” without any cells, representing in situ thread thickness and (b) “Green zone,” including the closest Live cells, representing the maximum injury to the tissue. The exact diameters of suture needles and threads were separately measured under an optical microscope. Results The diameters of the Black (from 144 to 219 µm) and the Green zones (from 282 to 487 µm) varied between the different sutures ( P < 0.001). The Green/Black zone ratio remained relatively constant (from 1.9 to 2.2; P = 0.767). A positive correlation between thread diameters and PDS suturing material, toward the Black and Green zone, was established, but needle diameters did not reveal any influence on the zones. Conclusions The width of acute cartilage injury induced by the trans-articular sutures is about twice the thread thickness inside of the tissue. Less compressible monofilament PDS induced wider tissue injury in comparison to a softer braided Vicryl. Needle diameter did not correlate to the extent of acute cartilage injury.

Macroscopic on-site evaluation (MOSE) of specimens from solid lesions acquired during EUS-FNB: multicenter study and comparison between needle gauges

Background and study aims The standard method for obtaining samples during endoscopic ultrasonography (EUS) is fine-needle aspiration (FNA), the accuracy of which can be affected by the presence of a cytopathologist in endoscopy room (rapid on-site evaluation [ROSE]). With the introduction of fine-needle biopsy (FNB), macroscopic on-site evaluation (MOSE) of a acquired specimen has been proposed. Only a few studies have evaluated the role of MOSE and in all except one, a 19G needle was used. Our primary aim was to evaluate the diagnostic yield and accuracy of MOSE with different needle sizes and the secondary aim was to identify factors influencing the yield of MOSE. Patients and methods Data from patients who underwent EUS-FNB for solid lesions, with MOSE evaluation of the specimen, were collected in six endoscopic referral centers. Results A total of 378 patients (145 F and 233 M) were enrolled. Needles sizes used during the procedures were 20G (42 %), 22G (45 %), and 25G (13 %). The median number of needle passes was two (IQR 2–3). The overall diagnostic yield of MOSE was of 90 % (confidence interval [CI] 86 %–92 %). On multivariable logistic regression analysis, variables independently associated with the diagnostic yield of MOSE were a larger needle diameter (20G vs. 25G, OR 11.64, 95 %CI 3.5–38.71; 22G vs. 25G, OR 6.20, 95 %CI 2.41–15.90) and three of more needle passes (OR 3.39, 95 %CI 1.38–8.31). Conclusions MOSE showed high diagnostic yield and accuracy. Its yield was further increased if performed with a large size FNB needles and more than two passes.

A Vibration Sensor Approach to Detect Intra-Articular Needle Tip Placement in the Knee Joint

Background: Intra-articular injection in the dry knee joint is technically challenging particularly for the beginners. The aim of this study was to investigate the possible use of the vibration sensor to detect if the needle tip was at the knee intra-articular position by characterizing the frequency component of the vibration signal during empty syringe air injection.Methods: Two milliliters of air were injected supero-laterally at extra- and intra-articular positions of a cadaveric knee joint, using needles of size 18, 21 and 24 gauge. Ultrasonography was used to confirm the positions of needle tip. A piezoelectric accelerometer was mounted medially on the knee joint to collect the vibration signals which were analyzed to characterize the frequency components of the signals during injections. Results: The vibration frequency band power in the range of 500-1,500 Hertz was visually observed to potentially localize the needle tip placement during air injection whether they were at the knee extra-articular or intra-articular positions, as demonstrated by the higher band power (over -40 decibel or dB) for all the needle sizes. The differences of frequency band power between extra- and intra-articular positions were 18.1 dB, 26.4 dB and 39.2 dB for the needle size 18, 21 and 24 gauge respectively. The most obvious difference was found in the smallest needle diameter.Conclusions: A vibration sensor approach was preliminarily proved to distinguish the intra-articular from extra-articular needle placement in the knee joint. This study demonstrated a possible alternative electronic device implementation of this technique to detect the intra-articular knee injection.

Hydrophobic performance of electrospun fibers functionalized with TiO2 nanoparticles

The development of materials with hydrophobic properties has been widely explored in areas such as textiles, healthcare, sports, and personal protective equipment. Hydrophobic properties that arise from nanoparticles (nPs) directly promote other valuable properties, including self-cleaning capabilities, decreased bacterial growth, and increased comfort. In this study, biodegradable poly(ε-caprolactone) (PCL) nanofibers were functionalized by the incorporation of titanium dioxide (TiO2) nPs to develop water-repellent materials. The membranes were produced through electrospinning, and variables such as the polymer concentration, nP concentration, and needle diameter were optimized to achieve PCL/TiO2 composite fibers with water-repellent capabilities. The nanofibers were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and the water contact angle (WCA). In general, it was observed that the nanofibers presented higher roughness values when TiO2 nPs were present and that this result promoted higher WCA values. The highest WCA value (156°) was obtained for the nanofiber mat produced with 20% weight-to-volume (w/v) PCL and 0.6% (w/v) TiO2.

Development of Filter Media by Electrospinning for Air Filtration of Nanoparticles from PET Bottles

Air pollution and solid pollution are considered global problems, and endanger human health mainly due to the emission of fine particulate matter released into the atmosphere and improper disposal of post-consumer plastic bottles. Therefore, it is urgent to develop filter media to effectively protect the public. The properties of plastics make them potential candidates for nanofiber mat formers due to their attractive structural and mechanical characteristics. This work aims to produce and evaluate novel PET electrospun fibers dispensed with the use of support materials to be used as filter media to remove nanoparticles from the air. The electrospinning process was carried out by changing the concentration of the polymer solution, the needle diameter, and the electrospinning processing time at two rotation speeds. The average diameters of the micro- and nanofibers of the filter media produced ranged from 3.25 μm to 0.65 μm and it was possible to conclude that, as the size of the fibers decreased, the mechanical strength increased from 3.2 to 4.5 MPa. In filtration tests, a collection efficiency of up to 99% with low-pressure drops (19.4 Pa) was obtained for nanoparticles, demonstrating high quality factor filter media, which could be applicable in gas filtration.

What Should Be Adequate PRP Dose for an Effective Treatment? An In-Vitro Experimental Study on the Skin

Background The clinical results of many studies on platelet-rich plasma (PRP) differ because there is a lack of standardization in PRP preparation and administration, as well as many variables such as PRP preparation methods, platelet concentration, and platelet activation. Objectives The aim of this study was to investigate a different variable that will affect PRP application results. How much PRP should be injected into the unit area of tissue for an effective PRP treatment? Methods The study was performed on fresh surplus tissues of 20 patients that were discarded in abdominoplasty and mammoplasty operations. 9 areas that were 4cm 2 in size were marked on the skin. Fluorescein-stained PRP was injected intradermally by using 3 different gauge needles and 3 different doses (0.01, 0.03, and 0.05 ml). After injections, spreads of the fluorescent dye-covered areas in horizontal and vertical planes were measured and compared. For the horizontal plane measurements, the dye spread was measured, first from the surface of skin and a second measurement was done from the dermal surface of skin. In addition, the width and depth of the dye spread in the dermis were measured from vertical sections. Results Changing the needle diameter does not affect the width or depth (thickness) of the PRP spread in the dermis. Increasing the applied dose to 0.03 ml increases the spread to the width and depth (thickness). Conclusions In research for evaluating the effectiveness of PRP treatments, it is necessary to report the volume of PRP to be applied per unit tissue.