Three-Dimensional Printing of Recycled Polypropylene and Activated Carbon Coatings for Harmful Gas Adsorption and Antibacterial Properties.

In recent years, the utilization of three-dimensional (3D) printing has been expanding due to advances in technology and economic efficiency. One of the 3D printing technologies is fused deposition modeling, which can be used to create different kinds of products or prototypes from various polymer filaments. In this study, the activated carbon (AC) coating was introduced to the 3D outputs printed using recycled polymer materials to impart multi-functions such as adsorption of harmful gas and antimicrobial activities. A filament of uniform diameter (1.75 µm) and a filter template in the form of a 3D fabric shape were prepared through the extrusion and 3D printing processes, respectively, of the recycled polymer. In the next process, the 3D filter was developed by coating the nanoporous AC, produced from the pyrolysis fuel oil and waste PET, on the 3D filter template through direct coating. The 3D filters coated with the nanoporous activated carbon showed the enhanced adsorption capacity of 1038.74 mg of SO2 gas and the antibacterial properties of 49% removal of E. coli bacteria. As a model system, a functional gas mask that has harmful gas adsorption abilities and antibacterial properties has been produced by a 3D printing process.

Unstable Pathologic Vertebral Fractures in Multiple Myeloma : Propensity Score Matched Cohort Study between Reconstructive Surgery with Adjuvant Radiotherapy and Radiotherapy Alone.

OBJECTIVE: Although radiotherapy (RT) is recommended for multiple myeloma (MM) involving spine, the treatment of choice between reconstructive surgery with RT and RT alone for pathologic vertebral fractures (PVFs) associated with structural instability or neurologic compromises remains controversial. The purpose of this study was to evaluate the clinical efficacies of reconstructive surgery with adjuvant RT for treatment of MM with PVFs by comparing with matched cohorts treated with RT alone. METHODS: Twenty-eight patients underwent reconstructive surgery followed by RT between 2008 and 2015 in a single institution, for management of PVFs associated with structural instability of the spine and/or neurologic compromises (group I). Twentyeight patients were treated with RT alone (group II) after propensity score matching in a 1-to-1 format based on instability of the spine, as well as age and performance. Clinical outcomes including the overall survival rates, duration of independent ambulation, neurological status, and numeric rating scale (NRS) for back pain were compared. RESULTS: Clinical and radiological features before treatment were similar in both groups. The median survival period was similar between the two groups. However, the mean duration of independent ambulation was significantly longer in group I (88.8 months; 95% confidence interval [CI], 66.0-111.5) than in group II (39.4 months; 95% CI, 25.2-53.6) (log rank test; p=0.022). Deterioration of Frankel grade (21.4% vs. 60.7%, p=0.024) and NRS for back pain (2.7±2.2 vs. 5.0±2.7, p=0.000) at the last follow-up were higher in the group II. Treatment-related complications were similar in both groups. CONCLUSION: In patients with unstable PVFs due to MM, reconstructive surgery may yield superior clinical outcomes compared with RT alone in maintaining independent ambulation and neurological status, as well as pain control despite similar median survival and complications.

Plain Radiographs Underestimate Varus Deformity of the Tibial Plafond.

Understanding plain radiograph in association with 3-dimensional (3D) morphology of the ankle is essential for treatment about varus ankle osteoarthritis (OA). The aims of this study were to investigate whether the alignment of the tibial plafond as determined on plain radiograph reflected the alignment of the tibial plafond on computed tomography (CT) in varus ankle OA and whether the alignment of the tibial plafond changed as the OA progressed. The 3D CT and plain radiographs from 101 ankles with varus ankle OA were analyzed and compared with 40 ankles in control group. The tibial plafond was assessed in the coronal and sagittal planes using 3D CT. The medial angle between the vertical line and the tibial plafond was measured on 3 different coronal plane CT images which was anterior, middle and posterior area of the tibial plafond. The medial distal tibial angle on plain radiograph reflected the posterior area of the tibial plafond on CT. The amount of varus angulation on CT was larger in anterior and middle area of the tibial plafond than the posterior area. There was a difference in the degree of varus of the tibial plafond between control group and OA patients; however, there was no difference among patients in different stages of varus ankle OA. Weightbearing plain radiographs underestimate the varus deformity in anterior and middle area of the tibial plafond and there is no significant difference in deformity of the tibial plafond among patients in different stages of varus ankle OA.

Primary radial nerve palsy associated with humeral shaft fractures according to injury mechanism: is early exploration needed?

BACKGROUND: Radial nerve palsy is a common complication associated with humeral shaft fractures. The purposes of this study were (1) to evaluate the status of primary radial nerve palsy in patients with humeral shaft fracture according to injury mechanism, (2) to estimate the risk factors of primary RNP, and (3) to evaluate whether early exploration is helpful for radial nerve recovery. METHODS: This study analyzed 162 patients with humeral shaft fractures from January 2014 to December 2019. All patients were surgically treated in our hospital. Of these, 109 high-energy injuries were identified and compared with 53 low-energy injuries. The risk factors of radial nerve palsy were analyzed, and the prevalence of radial nerve palsy and status of radial nerve exploration according to injury mechanism were evaluated. Nerve recovery rate according to early nerve exploration was investigated. RESULTS: There were 31 cases of radial nerve palsy among 162 patients: 27 in the high-energy humeral shaft fracture group and 4 in the low-energy humeral shaft fracture group. Logistic regression analysis for risk factors showed that the injury mechanism was significantly associated with primary radial nerve palsy. Among 31 radial nerve palsy patients, 21 radial nerves were explored and 19 radial nerves recovered completely (80.6%). In the high-energy humeral shaft fracture group, 18 radial nerves were explored during surgery among 27 radial nerve palsy cases, and 16 cases recovered (88.9%). The other 9 radial nerves were not explored, and only 5 cases recovered (55.6%). CONCLUSIONS: This study confirmed that the incidence of radial nerve paralysis was higher in high-energy humeral shaft fractures than in low-energy fractures. The more common fracture patterns were oblique, transverse, wedge, and comminuted in high-energy humeral shaft fracture. This study suggests that these patterns are not directly associated with radial nerve palsy, but that high-energy injury is associated with a specific fracture pattern. Early nerve exploration during surgical treatment in patients with radial nerve palsy associated with humeral shaft fracture was helpful especially after high-energy injury.

Treatment of unusual locked posterior fracture-dislocation of the shoulder: a case series.

BACKGROUND: Locked posterior fracture-dislocation of the shoulder (LPFDS) is a very rare injury that occurs predominantly in young patients following high-energy trauma. The long-term outcome of the treatment of this injury is often poor. This study sought to present the characteristics of injury, discuss the pathological anatomy, and to report the treatment outcomes of our case series. METHODS: Between January 2012 and May 2018, a total of 234 patients who underwent surgical treatment for proximal humerus fractures were reviewed. Among them, six patients (mean age, 54.7 years; range, 35-76 years) with LPFDS were included in this study. Four patients were treated with open reduction and internal fixation (ORIF) with locking plates, one with hemiarthroplasty, and one with reverse total shoulder arthroplasty. Clinical results were evaluated by Constant, American Shoulder and Elbow Surgeons (ASES), and visual analog scale (VAS) scores and radiologic evaluation was conducted using follow-up radiographs. RESULTS: The mean length of follow-up was 26.2 months (range, 12-54). The mean Constant, ASES, and VAS scores were 66.7, 65.5, and 2.2, respectively. Four patients who underwent ORIF achieved bony union, but avascular necrosis (AVN) of the humeral head was observed in two patients. No complications were observed in the patients who underwent arthroplasty surgery until final follow-up. CONCLUSIONS: In the treatment of LPFDS, replacement arthroplasty can produce predictable results. The approach of ORIF may be considered as a first choice of treatment in young patients but is sometimes correlated with postoperative complications such as AVN and the functional outcomes may be unpredictable. Therefore, patients should undergo careful diagnosis and treatment of this type of injury.

A Low-Temperature, Solution-Processable, Cu-Doped Nickel Oxide Hole-Transporting Layer via the Combustion Method for High-Performance Thin-Film Perovskite Solar Cells.

Low-temperature, solution-processable Cu-doped NiOX (Cu:NiOx ), prepared via combustion chemistry, is demonstrated as an excellent hole-transporting layer (HTL) for thin-film perovskite solar cells (PVSCs). Its good crystallinity, conductivity, and hole-extraction properties enable the derived PVSC to have a high power conversion efficiency (PCE) of 17.74%. Its general applicability for various elecrode materials is also revealed.

Simplified clinical risk score to predict acute kidney injury after aortic surgery.

OBJECTIVE: The authors identified risk factors for acute kidney injury (AKI) defined by risk, injury, failure, loss, end-stage (RIFLE) criteria after aortic surgery with cardiopulmonary bypass and constructed a simplified risk score for the prediction of AKI. DESIGN: Retrospective and observational. SETTING: Single large university hospital. PARTICIPANTS: Patients (737) who underwent aortic surgery with cardiopulmonary bypass between 1997 and 2010. MAIN RESULTS: Multivariate logistic regression analysis was used to evaluate risk factors. A scoring model was developed in a randomly selected derivation cohort (n = 417), and was validated on the remaining patients. The scoring model was developed with a score based on regression ß-coefficient, and was compared with previous indices as measured by the area under the receiver operating characteristic curve (AUC). The incidence of AKI was 29.0%, and 5.8% required renal replacement therapy. Independent risk factors for AKI were age older than 60 years, preoperative glomerular filtration rate <60 mL/min/1.73 m(2), left ventricular ejection fraction <55%, operation time >7 hours, intraoperative urine output <0.5 mL/kg/h, and intraoperative furosemide use. The authors made a score by weighting them at 1 point each. The risk score was valid in predicting AKI, and the AUC was 0.74 [95% confidence interval (CI): 0.69 to 0.79], which was similar to that in the validation cohort: 0.74 (95% CI: 0.69 to 0.80; p = 0.97). The risk-scoring model showed a better performance compared with previously reported indices. CONCLUSIONS: The model would provide a simplified clinical score stratifying the risk of postoperative AKI in patients undergoing aortic surgery.

Detoxification of phenol through bound residue formation by birnessite in soil: transformation kinetics and toxicity.

Oxidative coupling reaction of phenol mediated by birnessite was studied in aqueous phase and soil. Phenol was readily transformed by birnessite and almost all phenol disappeared in both samples after 24 hours of reaction. Phenol transformation kinetics was investigated by plotting reaction time against logarithm concentrations of residual phenol, revealing that exponential decrease of phenol was evident both in aqueous phase and soil, and maximum removal rates were 2.31-2.54 times higher in the presence of soil. Reaction products of phenol were identified by LC-MS and capillary electrophoresis. In aqueous phase, polyphenols were formed by self-coupling reaction of phenoxy radicals whereas phenol was found to be present as bound residues in soil, probably due to the cross-coupling reaction between the radicals and soil organic matter. Microtox System was employed to determine the toxicity after birnessite treatment, and the toxicity of phenol-spiked solution and soil samples decreased remarkably compared to that of phenol solution before treatment.

Human health risk assessment of explosives and heavy metals at a military gunnery range.

In this research, a risk assessment was undertaken in order to develop the remediation and management strategy of a contaminated gunnery site, where a nearby flood controlling reservoir is under construction. Six chemicals, including explosives and heavy metals, posing potential risk to environmental and human health, were targeted in this study. A site-specific conceptual site model was constructed, based on effective, reasonable exposure pathways, to avoid any overestimation of the risk. Also, conservative default values were adapted to prevent underestimation of the risk when site-specific values were not available. The risks posed by the six contaminants were calculated using the API's Decision Support System for Exposure and Risk Assessment, with several assumptions. In the crater-formed-area (Ac), the non-carcinogenic risks (i.e., HI values) of tri-nitro-toluene (TNT) and Cd were slightly larger than 1, but for RDX (Royal Demolition Explosives) was over 50. The total non-carcinogenic risk of the whole gunnery range was calculated to be 62.5, which was a significantly high value. The carcinogenicity of Cd was estimated to be about 10(-3), while that for Pb was about 5 x 10(-4), which greatly exceeded the generally acceptable carcinogenic risk level of 10(-4)-10(-6). It was concluded from the risk assessment that there is an immediate need for remediation of both carcinogens and non-carcinogens before construction of the reservoir. However, for a more accurate risk assessment, further specific estimations of the changes in environmental conditions due to the construction of the reservoir will be required; and more over, the effects of the pollutants to the ecosystem will also need to be evaluated.