Clinical and radiographic outcomes of the treatment of adolescent idiopathic scoliosis with segmental pedicle screws and combined local autograft and allograft bone for spinal fusion: a retrospective case series

<p>Abstract</p> <p>Background</p> <p>High morbidity has been reported with iliac crest bone graft harvesting; however, donor bone is typically necessary for posterior spinal fusion. Autograft bone combined with allograft may reduce the morbidity associated with iliac crest bone harvesting and improve the fusion rate. Our aim in this study was to determine the presence of complications, pseudarthrosis, non-union, and infection using combined <it>in situ </it>local autograft bone and freeze-dried cancellous allograft bone in patients undergoing posterior spinal fusion for the treatment of adolescent idiopathic scoliosis.</p> <p>Methods</p> <p>A combination of <it>in situ </it>local autograft bone and freeze-dried cancellous allograft blocks were used in 50 consecutive patients with adolescent idiopathic scoliosis treated by posterior fusion and Moss Miami pedicle screw instrumentation. Results were assessed clinically and radiographically and quality of life and functional outcome was evaluated by administration of a Chinese version of the SRS-22 survey.</p> <p>Results</p> <p>There were 41 female and 9 male patients included for analysis with an average age of 14.7 years (range, 12-17). All patients had a minimum follow-up of 18 months (range, 18 to 40 months). The average preoperative Cobb angle was 49.8° (range, 40° to 86°). The average number of levels fused was 9.8 (range, 6-15). Patients had a minimum postoperative follow-up of 18 months. At final follow-up, the average Cobb angle correction was 77.8% (range, 43.4 to 92.5%). There was no obvious loss in the correction, and the average loss of correction was 1.1° (range, 0° to 4°). There was no pseudarthrosis and no major complications.</p> <p>Conclusions</p> <p><it>In situ </it>autograft bone combined with allograft bone may be a promising method enhances spinal fusion in AIS treated with pedicle screw placement. By eliminating the need for iliac crest bone harvesting, significant morbidity may be avoided.</p

Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano-ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaCl solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings

Corrosion inhibition of polyaniline for mild steel in hydrochloric acid solution

Abstract: Polyaniline (PANi) is one of the most widely studied conductive polymers. In this paper the corrosion inhibition behavior of PANi for mild steel in hydrochloric acid solution was investigated by weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electronic microscope (SEM) technology. The most important problem for the application of PANi as corrosion inhibitor is the solubility of PANi. Improved synthesis method was used to solve the solubility problem. After the addition to the solution, the inhibition efficiency can reach 90%. The existence of PANi can greatly reduce the corrosion rate of mild steel in hydrochloric acid solution. The adsorption obeys Langmuir adsorption isotherm

Fine grid scale increases or decreases the trade-off effect between ES in mountain protected areas?

A crucial challenge in ecosystem management is the identification of trade-off effects among multiple ecosystem services (ESs), particularly in complex and ecologically vulnerable mountainous protected areas. Nevertheless, investigations into the spatio-temporal dynamics of trade-offs and synergies among ES within such protected regions remain limited. This study concentrated on the Qilian Mountain, a critical ecologically fragile protected area, utilized the Invest model to comprehensively analyze six ESs over the period 1985–2020. Employed Pearson correlation coefficient, we scrutinized trade-off and synergy relationships of these ES across varying grid scales (30 m, 1 km, and 10 km). Furthermore, GeoDetector, in tandem with multi-source data, is employed to unveil the potential drivers influencing the patterns of ES. Our findings revealed that: (1) Increasing data spatial resolution refines grid scales, yielding smoother spatial distributions of ES, and accentuates spatial disparities. (2) Synergistic relationships prevailed among protected area ES from 1985 to 2020, with correlations between carbon storage - water yield and habitat quality - water yield shifted from synergy to trade-off in 2015. (3) Distinct grid scales exert non-linear impacts on ES correlations, affecting both the magnitude and direction of these relationships. (4) Interactions among natural factors, climate, and landscape patterns are principal drivers of spatial heterogeneity in ES, with the contributions of dominant drivers exhibiting temporal variability. Remarkably, factors with stronger driving forces demonstrate greater temporal instability in their contribution rates. Our research underscores the necessity for comparative assessments of ES and their interrelations at diverse data spatial resolutions, advocating for enhanced ES management strategies

Evaluation of Hydrogen Permeation into High-Strength Steel during Corrosion in Different Marine Corrosion Zones

Hydrogen permeation into high-strength steel during the corrosion process can deteriorate their mechanical properties, thus seriously threatening the safety of steel structures. However, the hydrogen permeation behavior of steels in corrosive marine environments is not well understood. In this study, the hydrogen permeation behavior and mechanism of AISI 4135 steel in different marine corrosion zones was investigated for the first time using an in situ hydrogen permeation monitoring system via outdoor and indoor tests. The three-month outdoor hydrogen permeation test showed that the diffusible hydrogen content of the steels exposed to the marine atmospheric, splash, tidal and immersion zone was 3.15 &times; 10&minus;3, 7.00 &times; 10&minus;2, 2.06 &times; 10&minus;2 and 3.33 &times; 10&minus;2 wt ppm, respectively. Meanwhile, results showed that the hydrogen permeation current density was positively correlated with the corrosion rate of the steel in the marine environments. This research is of great significance for guiding the safe application of high-strength steel in the marine environments

Evaluation of Hydrogen Permeation into High-Strength Steel during Corrosion in Different Marine Corrosion Zones

Hydrogen permeation into high-strength steel during the corrosion process can deteriorate their mechanical properties, thus seriously threatening the safety of steel structures. However, the hydrogen permeation behavior of steels in corrosive marine environments is not well understood. In this study, the hydrogen permeation behavior and mechanism of AISI 4135 steel in different marine corrosion zones was investigated for the first time using an in situ hydrogen permeation monitoring system via outdoor and indoor tests. The three-month outdoor hydrogen permeation test showed that the diffusible hydrogen content of the steels exposed to the marine atmospheric, splash, tidal and immersion zone was 3.15 × 10−3, 7.00 × 10−2, 2.06 × 10−2 and 3.33 × 10−2 wt ppm, respectively. Meanwhile, results showed that the hydrogen permeation current density was positively correlated with the corrosion rate of the steel in the marine environments. This research is of great significance for guiding the safe application of high-strength steel in the marine environments

Study on the Photocathodic Protection of Q235 Steel by CdIn2S4 Sensitized TiO2 Composite in Splash Zone

In this work, the photo-catalytic activity of TiO2 is considerably enhanced via sensitization with CdIn2S4, and its application for protecting Q235 from corrosion in splash zones is examined. TiO2 nanotube arrays (NTAs) are prepared on a flat Ti substrate via two-step anodization. CdIn2S4 is deposited on the surface of TiO2 NTAs by hydrothermal reaction. TiO2 NTAs with enormous specific surface areas and large-diameter hollow nanostructures are found to benefit the immobilization of CdIn2S4. As a narrow band gap semiconductor, CdIn2S4 is able to extend the light absorption range of TiO2, and the construction of an n&ndash;n type hetero-junction accelerates the separation of carriers. Strong solar light, which accelerates the corrosion of Q235 in the splash zone area, is converted into the necessary condition for protecting Q235 from corrosion. In this work, TiO2 is sensitized with MoS2 microspheres (MoS2/TiO2 nanocomposites), which were prepared on a flat Ti substrate via a two-step anodization and hydrothermal method, sequentially

Characteristics and mechanisms of low-alloy high-strength steel corrosion behavior under barnacle adhesion based on a comparison experiment

A comparative experiment was set up in a field site and laboratory to study the effect of barnacles (model organisms of macrofouling) on the corrosion behavior of a low-alloy high-strength steel. The results indicated that barnacle adhesion can slow the corrosion rate of steel in an immersion environment by hindering the diffusion of corrosive ions. It was found that barnacle adhesion had a significant promotion effect on localized corrosion. Due to steel’s high corrosion rate, the corrosion-impeding effect was improved, and the promotioneffect on localized corrosion was weakened. The study proposed a corrosion mechanism model influenced by barnacles