Evaluation and Comparison of Self-Made and Commercial Calibration Markers for Radiographic Magnification Correction in Veterinary Digital Radiography

Introduction Magnification error is always present in radiography and calibration is necessary, if high accuracy is required in pre-surgical planning. The goal of this study was to verify the use of self-made markers and calibration techniques and to establish guidelines for magnification correction. Methods We evaluated and compared spherical and linear markers of different sizes with focus on practicability, accuracy and precision. Markers were placed on foam pads or attached to flexible arms. Results Vertical marker deviation of 1 cm from the anatomical reference point corresponded to ∼1% of magnification error in our setting. Marker placement along the horizontal plane showed no significant magnification in the periphery of the radiograph. All markers showed good accuracy and the commercial spherical marker with a flexible segment arm had the best results regarding practicability. Discussion Our study suggests that marker type is not solely responsible for usability and accuracy but also the type of fixation. In the absence of a calibration marker, calculation of the magnification factor using a measurement tape during radiography is equally reliable. Use of a fixed averaged calculated calibration factor showed poor agreement compared with the marker calibration, probably due to variability in size of the animals. In conclusion, if precision matters, use of a calibration marker, which could be purchased or self-made, is advised.

Who are the multichannel shoppers and how can retailers use them? Evidence from the French apparel industry

PurposeThis study aims to identify, within the context of the French fashion industry, the characteristics of multichannel shoppers, that is, consumers who use more than one channel in a single shopping trip. We especially investigate whether consumers' focus on quality versus price affects their multichannel shopping tendency and their flexibilities in their shopping lists (basket flexibility).Design/methodology/approachWe surveyed a representative sample of 400 French shoppers regarding fashion apparel purchasing. We use a logistic regression framework to measure the probability of a shopper becoming a multichannel shopper based on the key constructs and a battery of control variables.FindingsThe analysis shows that, in fashion buying, shoppers focused on quality and those with high basket flexibility have a higher probability of becoming multichannel shoppers. The probability becomes even greater when a shopper is both quality oriented and has basket flexibility.Research limitations/implicationsWe focus on the fashion apparel market for a deeper understanding of multichannel usage of products with both experience and search features. Future research can investigate other industries for higher generalizability.Practical implicationsOur research provides insights into multichannel fashion companies whose managements aim to effectively manage high-value customers who tend to use more channels when shopping. Specifically, an omnichannel marketing strategy should focus on capturing the quality-oriented and highly basket-flexible segment of consumers.Originality/valueOur study provides evidence that for products having high experiential as well as search features, quality-oriented and highly flexible shoppers engage more in multichannel shopping. Because these characteristics are related to the long-term value of customers, we provide the link between multichannel marketing and firm profitability in the context of the fashion industry.

Microstructure and Mechanical/Elastic Performance of Biobased Poly (Butylene Furanoate)–Block–Poly (Ethylene Oxide) Copolymers: Effect of the Flexible Segment Length

The aim of this paper is to extend knowledge on biobased poly(butylene furanoate)–block–poly (ethylene oxide) (PBF-b-PEO) copolymers’ performance by studying the effect of the PEO segment’s molecular weight on the microstructure and materials behavior. As crystallization ability of PEO depends on its molecular weight, the idea was to use two PEO segment lengths, expecting that the longer one would be able to crystallize affecting the phase separation in copolymers, thus affecting their mechanical performance, including elasticity. Two series of PBF-block-PEOs with the PEO segments of 1000 and 2000 g/mol and different PBF/PEO segment ratios were synthesized by polycondensation in melt, injection molded to confirm their processability, and subjected to characterization by NMR, FTIR, DSC, DMTA, WAXS, TGA, and mechanical parameters. Indeed, the PEO2000 segment not only supported the crystallization of the PBF segments in copolymers, but at contents at least 50 wt % is getting crystallizable in the low temperature range, which results in the microstructure development and affects the mechanical properties. While the improvement in the phase separation slightly reduces the copolymers’ ability to deformation, it is beneficial for the elastic recovery of the materials. The investigations were performed on the injection molded samples reflecting the macroscopic properties of the bulk materials.

Role of minimally invasive percutaneous fixation in thoracolumbar fractures: a prospective study

Background Each year, there are approximately 5 million new vertebral fractures worldwide. Being a mobile flexible segment that is prone to severe stresses and loads, thoracolumbar fractures are considered one of the most controversial and challenging fracture types to manage. Objective The aim of this study is to explore the technique and to evaluate feasibility, safety, and outcome of percutaneous transpedicular fixation in the management of thoracolumbar fractures. Methods This study was carried out in the period between May 2016 and June 2017, where 20 consecutive patients with thoracolumbar fractures, based on TLICS scoring and neurological status, underwent a posterior percutaneous transpedicular fixation. The mean age was 33.85 years, range 20–49 years. Patients were followed up for 12 months. Patients had their clinical outcomes reviewed and evaluated in terms of cosmesis by visual analog scale (VAS) and in terms of Cobb angle correction. Results The length of the procedure varied from 120 to 180 min with mean time of 154.50 min. There was no significant blood loss in all cases. The volume of blood loss ranged from 150 to 200 cc with mean loss of 174.25 cc. No major intraoperative complications happened in our study cases. Six cases had only one laterally malpositioned screw each. All cases returned to their previous activity without limitations (E5). Those who were completely pain free (F5) were 15 patients. Only five patients were suffering from moderate pain (F4). The Prolo scale was either 9 or 10 with mean of 9.60. Conclusion By comparing our results with other studies, we found more or less equivalence in terms of neurological recovery, functional outcome, fusion rate, and maintenance of correction gain. However, the cosmesis scores for patients in the study were great.

Tunable Structure and Properties of Segmented Thermoplastic Polyurethanes as a Function of Flexible Segment

Segmented thermoplastic polyurethanes (PUs) were synthetized using macrodiols with different functional groups (carbonate, ester, and /or ether) as a segment with a molar mass of 1000 and 2000 g/mol, and 4,4’-diphenylmethane diisocyanate (MDI) and 1,4-butanediol as a rigid segment. The polyurethanes obtained reveal a wide variation of microphase separation degree that is correlated with mechanical properties and retention of tensile properties under degradation by heat, oil, weather, and water. Different techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR), and synchrotron small-angle X-ray scattering (SAXS) were used to determine rigid-flexible segments’ phase behaviour. Retention of tensile properties determines the stability of the samples under different external factors. This work reveals that pure polycarbonate-based macrodiols induce the highest degree of phase miscibility, better tensile properties, hardness shore A, and retention of tensile properties under external agents.

Effect of the Chain Structure of Self-Emulsifying Polyester Sizing Agent on ILSS of Carbon Fiber/Unsaturated Polyester Resin Composites

Herein, we report self-emulsifying anionic unsaturated polyester emulsions with different chain segments as novel sizing agents. The epoxy modified unsaturated polyester emulsions were synthesized via a self-emulsifying technique with no organic solvents. Emulsions were characterized by dynamic light scattering (DLS), Zeta potential, centrifuge, and cryo-scanning electron microscopy (Cryo-SEM). The results showed that the emulsions obtained were mono-dispersed nanospheres that had adequate colloidal stability. The maximum Zeta potential of the sizing agent is −52.88 mV. In addition, these emulsions were investigated as the sizing agents in order to improve interfacial adhesion between carbon fibers (CFs) and unsaturated polyester resin (UPR). Compared with the CFs sized with the commercial epoxy sizing agent, the interlaminar shear strength (ILSS) of CF/UPR composites from the CFs sized by these emulsion sizing agents with three different chain structures were enhanced by 25%, 29%, and 42%, respectively. The emulsion sizing agent composed of a flexible segment synthesized from adipic acid, neopentyl glycol, and maleic anhydride is most effective and can achieve the highest enhancement of the ILSS of CF/UPR composites.