Purpose To investigate the impact of failed Pavlik harness (PH) treatment on the outcomes following closed reduction (CR) or open reduction (OR) in developmental dysplasia of the hip (DDH). Methods Ninety-three DDH patients treated with CR or OR were enrolled. One group of which received previous PH treatment (F group) and the other (L group) not. The clinical outcomes were evaluated according to McKay's criteria. Radiographs were evaluated for acetabular index (AI) and the degree of dislocation of the hips. Results A higher rate of CR was found in F group (P = 0.034). Before CR/OR, the mean AI in F group was significantly lower than that in L group (P = 0.000), while at the last follow-up, the AIs in both groups were all improved. In F group, there were 7 (16.67%), 18 (42.86%) and 17 (40.48%) hips were classified as Graf type II, III and IV pathologic changes, respectively, when PH treatment started, while the corresponding data were 17 (40.48%), 17 (40.48%) and 8 (19.05%) after PH treatment (P = 0.024). At the last follow-up, no significant difference was found concerning the complications between the two groups (P > 0.05). Conclusions PH treatment, even if failed, may have the ability of accelerating the development of the acetabulum and increasing the rate of successful CR. Thus we advocate a trial of PH treatment for all DDH patients less than 6 months of age. Meanwhile, a close monitoring by dynamic ultrasonography is required due to the risk of AVN.

BACKGROUND:Hip dysplasia is one of the most prevalent disorders in children and one of the three primary congenital orthopedic deformities. Although there are numerous existing methods (e.g., CT, MRI and arthrography) for early identification of hip dysplasia, their diagnostic criteria differ widely. It is critical to establish a safe, accurate, and reliable way for early diagnosis and treatment of hip dysplasia. OBJECTIVE:This study aimed to analyze the diagnostic efficacy of high-frequency ultrasound (HFU) for congenital developmental hip dysplasia and hip dislocation and to provide a reference for the early diagnosis of congenital hip dysplasia in the future. METHODS:A total of 104 infants and children suspected of having congenital hip dislocation or developmental hip dysplasia admitted to our hospital from April 2019 to August 2022 were enrolled as study subjects. All the infants and children were subjected to HFU and X-ray examination in our hospital. The diagnostic efficacy of HFU for congenital hip dysplasia was observed using X-ray as the gold standard. RESULTS:HFU confirmed 79 cases of congenital hip dysplasia, while X-ray confirmed 71 cases. The sensitivity and specificity of HFU were 77.42% and 83.33%, respectively, in the diagnosis of congenital developmental hip dysplasia, 76.47% and 96.55% in the diagnosis of congenital hip dislocation, and 77.22% and 60% in the diagnosis of congenital hip abnormality, which is very close to the gold standard. According to statistics on infants and children, the majority of patients were girls, and the left joint was more likely to be affected. CONCLUSION:HFU has excellent diagnostic efficiency for congenital developmental hip dysplasia and hip dislocation, which can be considered an early assessment method for congenital hip dysplasia in the future.

Copper (Cu) is a widely recognized cathode for the electrochemical reduction of nitrate (NO3-). Nevertheless, its practical applications are currently restricted due to limited activity and selectivity, particularly at low NO3- concentrations. Herein, a Cu-Pd bimetallic cathode system was designed for NO3- reduction reaction with low NO3- concentrations (≤40 mg-N L-1). In this system, a Cu nanowire array cathode was utilized for NO3- reduction, while a Pd/C particle cathode was employed for NO2- reduction with H2 generated in situ from a polypyrrole electrode. Due to the improved mass transfer and active sites derived from Pd/C particle cathode, along with the synergistic effects of NO3- reduction and NO2- reduction, the constructed Cu-Pd bimetallic cathode system achieved a 7.32-fold increase in NO3– removal rate and a 1.70-fold increase in NH4+ selectivity compared to the traditional Cu cathode. This performance surpassed that of many other state-of-the-art Cu-based cathodes under similar conditions. Moreover, the Cu-Pd bimetallic cathode system displayed high reusability, and extremely low Cu and Pd leaching. Additionally, it showed strong resistance to environmental factors and can adapt to a wide pH range (3-9) and various NO3- concentrations (10-40 mg-N L-1). The electron spin resonance and scavenger experiments confirmed that both direct electron transfer and indirect reduction by atomic H* were involved in the NO3- removal process, with indirect reduction playing a more significant role. Overall, our findings guide the design of superior catalytic systems for NO3- removal to enhance the activity and selectivity of NO3- reduction for efficient water purification.

Background:The distal radial metaphyseal-diaphysis junction fractures (DRMDJ) have various treatment methods and are easily lead to complications. This study aims to compare the anterograde elastic stable intramedullary nailing (ESIN-A), retrograde K-wire fixation (KW-R), and retrograde precision-shaping elastic intramedullary nailing (ESIN-RPS) for the treatment of pediatric DRMDJ fractures. Materials and methods:A total of 113 patients with DRMDJ fractures (36 in the ESIN-A group, 52 in the KW-R group, and 25 in the ESIN-RPS group) from two centres were retrospectively analysed. Perioperative operation time, intraoperative bleeding, fluoroscopy times, alignment rate and angulation on radiography were compared among the three groups. Forearm rotation, healing, wrist function, and complications were compared at the last follow-up. Results:The mean operation times of the three groups were as follows: KW-R (72 ± 13 min) > ESIN-A (65 ± 18 min) > ESIN-RPS (52 ± 11 min), with a significant difference (P < 0.01). The incision length and intraoperative blood loss of ESIN-A (1.8 ± 0.2 cm; 8.3 ± 3.7 ml) were significantly higher than ESIN-RPS (1.4 ± 0.8 cm; 5.5 ± 2.7 ml) (P < 0.05), respectively. The postoperative alignment rate on the anteroposterior (AP) and the lateral plane of ESIN-RPS (93.1 ± 4.4%; 95.01 ± 2.8%) was significantly greater than that of KW-R (82.1 ± 6.8%; 88.5 ± 4.5%) and ESIN-A (79.2 ± 5.2%; 83.2 ± 2.5%) (P < 0.01). The residual angulation of ESIN-RPS (3.3 ± 1.2°; 2.9 ± 0.8°) was significantly greater than that for ESIN-A (5.1 ± 1.7°; 4.9 ± 2.1°) and KW-R (6.6 ± 2.8°; 7.5 ± 1.6°) (P < 0.05). The excellent and good ratio of ESIN-RPS (95.8%) was significantly higher than that of ESIN-A (86.5%) and KW-R (86.1%) according to the Gartland-Werley standard. There was a significant difference in delayed union between the KW-R and ESIN-A (P < 0.05). Additionally, there were two cases of radial nerve injury in the ESIN-A group, one case of tendon rupture in the ESIN-RPS group, and one case of tendon rupture in the KW-R group. The ESIN-RPS group had significantly fewer complications than the KW-R group (P < 0.05). The ESIN-A group also had significantly fewer complications than the KW-R group (P < 0.05). Conclusion:Compared with ESIN-A and KW-R, ESIN-RPS has the advantages of a shorter operation time, less intraoperative blood loss, less radiation, better alignment, and fewer complications. The ESIN-RPS was suggested as an optimal choice for paediatric DRMDJ fractures.

Abstract Background:Developmental hip dysplasia(DDH) is a common pediatric disease.For patients younger than 6 months of age,ultrasound diagnosis is more suitable for screening and assessment of hip development.At present,there is an urgent need for a reproducible and reliable ultrasound screening method for DDH diagnosis. Purpose: To construct and verify an artificial intelligence-assisted deep learning system for ultrasound diagnosis of developmental hip dysplasia in children. Materials and Methods: 2021 standard sections were selected from January 2019 to January 2021. All standard sections were annotated using unified standards through the image transmedia data annotation and audit system.1753 images were randomly selected to train the deep learning system,the remaining 268 were used to test the system. Results: 268 patients were tested. The AUC for diagnosing hip joint maturity was 0.941, (sensitivity 90.5%, specificity 97.8%),while the AUC for Graf classification was 0.685(sensitivity 45.3% specificity 91.7%),compared with clinicians’ measurements. According to the Bland–Altman method, the 95% limits of agreement of α angle was-6.426°~4.811°(Bias=-0.8075,P < 0.001), that of β angle was -5.545°~6.507°(Bias=0.4812,P=0.057). 7 key points measured by AI were statistically different from the clinician values. Conclusions: The artificial intelligence system could quickly and accurately measure the Graf correlation index of standard hip joint ultrasound images.

Elbow fracture is one of the most common fractures in preschool children, and the secondary ossification center appears regularly with age increasing. Transphyseal separation of the distal humerus, medial humeral condyle fracture, lateral humeral condyle fracture, radial head osteochondral separation, and Monteggia fracture (minimal ulnar bow type) are difficult to diagnose based on X-ray films alone because of the unossified secondary ossification center or a suspicious non-alignment of the anatomical cartilage of the elbow joint in preschool children. These 5 fractures above are defined as The Radiographic Appearance Seemed Harmless fractures in preschool children (TRASH-PS). The TRASH-PS fractures must be taken into consideration when there is swelling at the injured site without fracture feature on X-ray. Additionally, relevant misdiagnosis or unsuitable management can lead to elbow dysfunction and deformity. Therefore, this work reviews the application of ultrasound in the management of TRASH-PS fractures.

Objective:To investigate the effectiveness of medial and lateral column periosteal hinge reconstruction using Kirschner wire in the closed reduction of multi-directional unstable humeral supracondylar fractures in children.Methods:A clinical data of 43 children with multi-direction unstable humeral supracondylar fractures, who met the selection criteria and were admitted between August 2020 and August 2022, was retrospectively analyzed. Twenty-one cases of fractures were treated wuth closed reduction after medial and lateral column periosteal hinge reconstruction using Kirschner wire and percutaneous Kirschner wires fixation (study group), while 22 cases of fractures were treated by traditional closed reduction technique and percutaneous Kirschner wire fixation (control group). There was no significant difference in gender, age, cause of injury, fracture side, and interval from injury to operation between the two groups ( P>0.05). The operation time, intraoperative fluoroscopy times, the number of children who were changed to open reduction after closed reduction failure, fracture healing time, complications within 2 months after operation, and the Flynn score of elbow joint function at last follow-up were compared between the two groups.Results:All the fractures in the study group were successfully closed reduction, and 4 cases in the control group were changed to open reduction and completed the operation, the difference between the two groups was significant ( P=0.040). The operation time and intraoperative fluoroscopy times of the study group were significantly less than those of the control group ( P<0.05). All children in both groups were followed up 6-18 months with an average of 9.0 months in the study group and 9.8 months in the control group. Imaging review showed that the fractures of both groups healed, and the difference in the healing time between the two groups was not significant ( P=0.373). According to Flynn score at last follow-up, the excellent and good rate of elbow joint function was 95.2% (20/21) in the study group and 86.4% (19/22) in the control group, with no significant difference ( P=0.317). There was no complication such as infection or irritation at the end of Kirchner wire within 2 months after operation.Conclusion:For children with multi-directional unstable humeral supracondylar fractures, the use of Kirschner wires to reconstruct the medial and lateral column periosteal hinge to assist in closed reduction has the advantages of shortening operation time, reducing intraoperative fluoroscopy times, and effectively reducing the incidence of open reduction, and can achieve similar postoperative elbow joint function when compared with traditional closed reduction technique.

Spectrum sharing between radar and communication systems has attracted substantial recent research attention. In order to avoid the mutual interference, source separation of the aliasing signal is a promising solution for joint communication and radar (JCR) sensing. However, most of the existing source separation methods are very sensitive to wide-band signals with rapidly varying instantaneous amplitude (IA) and not applicable to scenarios with complex overlapping subsignals. To overcome the above limitations, a data-driven sparsity-based source separation method is proposed. Without depending on signal parameters, a sparse signal observation model of the received signal is established. Then, source separation is transformed into estimation of the IA and instantaneous frequency (IF), and an iterative method is developed. Moreover, the Cramér-Rao lower bound (CRLB) of the source separation error (SSE) variance is derived based on the CRLB of IA and IF. Simulation results demonstrate that our proposed method is superior to the benchmark schemes and is robust to noise and initial IF errors.

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH). In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi–MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN. In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32

Carbon-supported copper is a well-known catalyst for the electrocatalytic reduction of nitrate to ammonium/ ammonia (ECRNA). However, relatively low Cu utilisation and/or restricted ECRNA performance currently limit its practical applications. Here, we report a novel carbon nanotubes (CNTs)-supported Cu catalyst (IE-Cu/CNTs) for ECRNA fabricated through ion-exchange/electroreduction method. Versus traditional CNTs-supported Cu catalysts, the IE-Cu/CNTs have a small particle size of Cu. Moreover, an increased electrochemical surface area and improved electron transfer were observed for the IE-Cu/CNTs, resulting in a 2.22fold increase in the mass activity of the ECRNA, indicating enhanced Cu utilisation and ECRNA performance. In addition, the IE-Cu/CNTs exhibited high stability for ECRNA. Electrokinetic analysis, scavenging experiments, and online electrochemical mass spectrometry measurements confirmed that ECRNA is regulated over the IE-Cu/CNTs by both direct electron transfer reduction and indirect atomic hydrogen reduction, with the former being the main regulator. This work offers new suggestions for the design of high-performance catalysts for ECRNA and deepens the understanding of the ECRNA mechanism on Cu-based catalysts.

Abstract Background Multidirectionally unstable supracondylar fracture of the humerus often requires open reduction. We present a simple technique for closed reduction using a Kirschner wire reconstruction-based treatment of internal and lateral column periosteal hinge for the treatment of multidirectionally unstable supracondylar fractures of the humerus in children. Methods A retrospective cohort study was conducted to analyse the clinical data of 43 patients (27 male and 16 female; mean age: 3–13 [7.0±2.5] years old) with multidirectionally unstable supracondylar fractures of the humerus treated in our Hospital from August 2020 to August 2022. They were divided into two groups according to the development of surgical techniques in our hospital. From September 2021 to August 2022,Twenty-one cases were treated with Kirschner wire reconstruction of the internal and lateral columns periosteum hinge assisted by closed reduction and Kirschner wire internal fixation (study group), and from August 2020 to August 2021, Twenty-two cases were treated with closed reduction and Kirschner wire internal fixation (control group). The operation time, intraoperative fluoroscopy times, percentage of patients who underwent open reduction after failure of closed reduction (incision rate), fracture healing time, Baumann Angle, and Flynn score of elbow function at the last follow-up were compared between the two groups. Complications such as infection and irritation of Kirschner wire tail were observed in the two groups 2 months after the operation. Results All patients were followed-up for 4–18 months ([8.6±4.2] months). The average operation time of the control group was 84.5 min (range: 51.0–111.0 min), which was significantly longer than that of the study group 34.4 min (range: 25.5–41.5 min) (P<0.05). The number of intraoperative fluoroscopy (30.0±8.9) in the control group was significantly higher than that in the study group (16.4±6.2) (P<0.05). The incision rate of the control group was 18% while that of thestudy group was 0 (P<0.05). The fracture healing time of the control group and the study group were 4.6±1.1 weeks and 4.3±0.7 weeks, respectively (P>0.05). Baumann Angle was 71.0±2.1° in the control group and 71.0±2.6° in the study group (P>0.05). According to Flynn score, the excellent and good rates of the elbow joint in the control group was 86.3%(19/21), including 17 excellent, 2 good, 3 fair, and 0 bad cases. The excellent and good rate of the elbow joint in the study group was 95.2%(20/21), including 18 excellent, 2 good, 1 fair, and 0 bad cases (P>0.05). No infection or Kirschner wire tail irritation occurred in the two groups during the 2-month follow-up. ConclusionReconstruction of internal and lateral periosteal hinges with Kirscher wire has similar effects to closed reduction and Kirschner wire fixation in the treatment of multidirectionally unstable supracondylar fractures of the humerus in children, but it can shorten the operation time, reduce intraoperative fluoroscopy times and incision rate.

Objective:To explore the effectiveness of thumb blocking technique through closed reduction of ulnar Kirschner wire threading in the treatment of Gartland type Ⅲ supracondylar humerus fractures in children. Methods:The clinical data of 58 children with Gartland type Ⅲ supracondylar humerus fractures treated with closed reduction of ulnar Kirschner wire threading by thumb blocking technique between January 2020 and May 2021 were retrospectively analyzed. There were 31 males and 27 females with an average age of 6.4 years ranging from 2 to 14 years. The causes of injury were falling in 47 cases and sports injury in 11 cases. The time from injury to operation ranged from 24.4 to 70.6 hours, with an average of 49.6 hours. The twitch of ring and little fingers was observed during operation, the injury of ulnar nerve was observed after operation, and the healing time of fracture was recorded. At last follow-up, the effectiveness was evaluated by Flynn elbow score, and the complications were observed. Results:There was no twitch of the ring and little fingers when the Kirschner wire was inserted on the ulnar side during operation, and the ulnar nerve was not injured. All children were followed up 6-24 months, with an average of 12.9 months. One child had postoperative infection in the operation area, local skin redness and swelling, and purulent secretion exudation at the eye of the Kirschner wire, which was improved after intravenous infusion and regular dressing change in the outpatient department, and the Kirschner wire was removed after the initial healing of the fracture; 2 children had irritation at the end of the Kirchner wire, and recovered after oral antibiotics and dressing change in the outpatient department. There was no serious complication such as nonunion and malunion, and the fracture healing time ranged from 4 to 6 weeks, with an average of 4.2 weeks. At last follow-up, the effectiveness was evaluated by Flynn elbow score, which was excellent in 52 cases, good in 4 cases, and fair in 2 cases, and the excellent and good rate was 96.6%. Conclusion:The treatment of Gartland type Ⅲ supracondylar humerus fractures in children by closed reduction and ulnar Kirschner wire fixation assisted with thumb blocking technique is safe and stable, and will not cause iatrogenic ulnar nerve injury.

Objective:To compare the effectiveness of ultrasound- and arthrography-assisted Kirschner wire fixation in the treatment of Jakob type Ⅱ lateral condylar humerus fracture (LCHF) in children. Methods:A clinical data of 101 children with Jakob type Ⅱ LCHF, who met the selection criteria and were admitted between April 2021 and April 2022, was retrospectively analyzed. Of them, 47 cases were treated with ultrasound-assisted Kirschner wire fixation (group A), and 54 cases with arthrography-assisted surgery (group B). There was no significant difference in gender, age, cause of injury, fracture side, and disease duration between groups (P>0.05). Intraoperative fluoroscopy times, operation time, and hospital stay, Flynn elbow joint function score, and postoperative complications were recorded and compared between groups. X-ray examination was performed to observe the healing of fracture, and measure the carrying angle and the shaft-condylar angle (SCA). Results:The success rate of closed reduction was significantly higher in group A than in group B (P<0.05), and the intraoperative fluoroscopy times was significantly less in group A than in group B (P<0.05). There was no significant difference in operation time and hospital stay between groups (P>0.05). All children in both groups were followed up 12-18 months, with an average of 13.6 months. X-ray reexamination showed that the fractures of both groups healed, and the difference in healing time was not significant (P>0.05). At last follow-up, there was no significant difference in carrying angle and SCA between unaffected side and affected side in both groups and between groups A and B in affected side (P>0.05). There was no significant difference in Flynn elbow joint function score between groups (P>0.05). There were 18 cases of lateral spurs formation in group A, 1 case of pinning infection and 26 cases of lateral spurs formation in group B, and there was no significant difference in the incidence of the above complications (P>0.05). Conclusion:Compared with the arthrography, the ultrasound-assisted Kirschner wire fixation in the treatment of Jakob type Ⅱ LCHF in children can avoid the open reduction and decrease the number of intraoperative fluoroscopy, and obtain the good effectiveness.

OBJECTIVE:The objective of this study was to investigate the effect and mechanism of long noncoding RNA (lncRNA) on head and neck squamous cell carcinoma (HNSCC).STUDY DESIGN:RNA was extracted from HNSCC tissue and adjacent tissues and sequenced. Differentially expressed lncRNA and microRNA (miRNA) were screened. Quantitative real-time polymerase chain reaction was used to compare the expression of target lncRNA between human oral keratinocyte (HOK) and cancer cell lines. LAMB1-210 in SCC-4 and CAL-27 cells was downregulated by transfecting short hairpin RNA (shRNA). Methyl thiazolyl tetrazolium, wound healing, and Transwell assay were used to evaluate viability, migration, and invasion ability in SCC-4 and CAL-27 cells.RESULTS:Eighty-one lncRNAs were differentially expressed, of which 40 were upregulated, 41 were downregulated, and 280 miRNAs were differentially expressed. Compared with HOK cells, the expression of LAMB1-210 was significantly upregulated in FADU, SCC-4, and CAL-27 cells (P < .001). LAMB1-210 was successfully downregulated by shRNA-LAMB1-210 (P < .001), and downregulated LAMB1-210 inhibited the cell viability, migration, and invasion ability of SCC-4 and CAL-27 cells (P < .001).CONCLUSIONS:The expression of lncRNA and miRNA in HNSCC tissues differs from that in normal tissues. LAMB1-210 is significantly overexpressed in tumor cells and is related to their survival, migration, and invasion.

Objective:To investigate the short-term effectiveness of ultrasound-guided closed reduction by Kirschner wire provocation technique in the treatment of Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents.Methods:Between May 2019 and May 2022, 41 patients with Salter Harris types Ⅰ and Ⅱ distal tibial epiphyseal fractures were admitted, all of whom had periosteal entrapment on preoperative MRI, and 38 cases (92.7%) were confirmed to have periosteal entrapment by intraoperative ultrasound. There were 24 males and 14 females, the age ranged from 6.8 to 15.7 years, with an average of 10.7 years; and there were 20 cases of Salter Harris type Ⅰ and 18 cases of type Ⅱ. The time from injury to operation was 22-76 hours, with an average of 28.4 hours. The preoperative imaging examination showed excellent alignment in 4 cases, good in 20 cases, and poor in 14 cases. The ultrasound guided Kirschner wire provocation technique for closed reduction and percutaneous Kirschner wire internal fixation were performed. The operation time, intraoperative fluoroscopy frequency, fracture healing time, and complications were recorded. Anteroposterior and lateral X-ray films of the affected ankle joint were taken before operation, at 3 months after operation, and at last follow-up to observe the healing of the fracture, and anteroposterior X-ray films of the whole length of both lower limbs were taken to evaluate the alignment of the force lines of the affected limbs. The range of motion (ROM), visual analogue scale (VAS) score, and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used to evaluate ankle function. The mechanical lateral distal tibia angle (mLDTA) and the anatomic anterior distal tibia angle (aADTA) were measured.Results:The operation time ranged from 17 to 52 minutes, with an average of 22.6 minutes, and the intraoperative fluoroscopy frequency ranged from 3 to 11 times, with an average of 4.2 times. X-ray examination during operation and at 2 days after operation showed that anatomical reduction was achieved. All patients were followed up 10-24 months, with an average of 16.4 months. All fractures healed in 6.1-7.2 weeks, with an average of 6.3 weeks; no fracture displacement occurred, and the patients recovered to their pre-injury level of motion at 6 months after operation. Needle tail irritation occurred in 2 cases at 4 weeks after operation, and they recovered after symptomatic treatment. During the follow-up, there was no serious complication such as incision deep infection, bone nonunion, delayed union, and malunion. At last follow-up, the patients' alignment were all excellent, and the difference was significant when compared with preoperative one ( Z=-7.471, P<0.001). The VAS score, AOFAS ankle-hindfoot score, dorsiflexion-plantar flexion ROM, varus-valgus ROM, mLDTA, and aADTA significantly improved at 3 months after operation and last follow-up when compared with preoperative ones ( P<0.05).Conclusion:Ultrasound-guided closed reduction by Kirschner wire provocation technique for treating Salter-Harris types Ⅰ and Ⅱ periosteal entrapment of distal tibial epiphyseal fractures in children and adolescents is minimally invasive and safe.

In recent years, copper-based electrodes have attracted intense attention for the electrochemical reduction of nitrate (NO3-), the so-called ECRN. However, these electrodes suffer from low activity and selectivity. Herein, we report a novel Cu-based electrode (IE-Cu-400) for the ECRN fabricated by loading Cu-based nanoparticles onto graphite felt using in situ electrodeposition followed by annealing. Compared with traditional Cu-based electrodes, the IE-Cu-400 is comprised of smaller particles and the copper is present in a high oxidation state (Cu2+ in CuO). During operation, the CuO is converted to Cu, which is the active ECRN species. In addition, an increased surface area and high density of grain boundaries resulting from the reduction of CuO were observed for IE-Cu-400. This resulted in a 3.38-fold increase in the NO3- removal rate and a 1.36-fold increase in NH4+ selectivity. Further analyses revealed that the enhanced ECRN performance of IE-Cu-400 is linked to its increased number of active sites, as well as its improved adsorption and reduction ability for NO2-. Moreover, IE-Cu-400 displays high stability for the ECRN. Finally, the produced NH4+ was effectively oxidised to N2 with approximately 100% selectivity via chlorination. Hence, the two-stage treatment strategy (i.e. ECRN by IE-Cu-400 + chlorination treatment) presented here shows great potential for the complete electrocatalytic denitrification of water. Further, this work highlights the beneficial effect of decreasing the particle size and controlling the surface oxidation of Cu-based catalysts simultaneously for enhancing the ECRN and offers new suggestions for the design of high-performance electrode materials for the ECRN.

Background: Cubitus varus is a well-recognized late complication of supracondylar humerus fractures in children. Various osteotomies have been described to correct this deformity, but each has disadvantages. The purpose of this study was to investigate the outcomes of a surgical technique, lateral closing wedge osteotomy combined with centralization of the distal humeral fragment, in cubitus varus. Meanwhile, the occurrence of postoperative lateral condylar prominence was observed. Methods: From January 2015 to December 2019, 36 pediatric cubitus varus deformity patients who were treated with lateral closing wedge osteotomy combined with centralization of the distal fragment in our institution were included. The corrective osteotomies were performed through a standard lateral approach and fixed with crossed Kirschner wires. The preoperative and postoperative full-length anteroposterior and lateral radiographs of bilateral upper limbs were assessed. At the same time, clinical and radiologic parameters were reviewed. Lateral condylar prominence index (LCPI) and any other complications were evaluated. Results: The mean preoperative humerus-elbow-wrist angle (HEWA) on the affected side was 20.9 degrees of varus, which was significantly improved to 9.2 degrees of valgus postoperatively. The mean postoperative value of LCPI was −0.047. Postoperative LCPI and HEWA was compared with the normal side, and there was no significant difference. All of the patients had excellent clinical and radiographic alignment. No surgical complications and limitation of range of motion were noted. No patient complained of lateral bony prominence. Conclusion: Lateral closing wedge osteotomy by centralization of distal fragment is a safe and highly effective method and prevents lateral prominence with a minimal complication rate. We recommend this technique for the treatment of cubitus varus in children. Level of Evidence: Level IV Case series.

Objective:To compare the effectiveness of open reduction and internal fixation with plate and closed reduction and internal fixation with Kirschner wire (K-wire) in the treatment of intra-articular displaced calcaneal fractures in older children. Methods:A clinical data of 35 older children (37 feet) with intra-articular displaced calcaneal fractures who were admitted between November 2014 and November 2020 and met the selection criteria were retrospectively analyzed. Among them, 19 cases (20 feet) underwent open reduction and internal fixation with plate (plate group), and 16 cases (17 feet) underwent closed reduction and internal fixation with K-wire (K-wire group). There was no significant difference in gender, age, cause of injury, side and type of fracture, and time from injury to admission, and preoperative calcaneal Gissane angle and Böhler angle ( P>0.05). The postoperative calcaneal Gissane angle, Böhler angle, complications, and fracture healing were compared between the two groups. The ankle function was evaluated based on the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scoring system. Results:Incision necrosis occurred in 1 foot in the plate group after operation, which healed after symptomatic treatment; the other incisions in the two groups healed by first intention. All children were followed up 12-39 months (mean, 19 months). X-ray films showed that the fractures in both groups healed; the healing time was (2.65±0.71) months in the plate group and (2.24±1.38) months in the K-wire group respectively, with no significant difference ( t=1.161, P=0.253). At last follow-up, the calcaneal Gissane angle and Böhler angle returned to normal; and the difference between pre- and post-operation in the two group was significant (P<0.05), but there was no significant difference between the two groups in the difference between before and after operation ( P>0.05). In the plate group, the plate was removed at 11-22 months after operation (mean, 16.8 months). At last follow-up, the AOFAS ankle-hindfoot score in the plate group was 91.2±5.1, which was significantly higher than that in the K-wire group (86.9±6.1) ( t=2.316, P=0.027). The ankle function was rated as excellent in 15 feet, good in 4 feet, and fair in 1 foot in the plate group, and excellent in 14 feet and good in 3 feet in the K-wire group, and the difference between the two groups was not significant ( Z=1.712, P=0.092). Conclusion:For intra-articular displaced calcaneal fracture in older children, the open reduction and internal fixation with plate and closed reduction and internal fixation with K-wire can achieve good effectiveness, but the former has better recovery of ankle function.

BackgroundRotation of the distal fragment often occurs in flexion-type supracondylar humerus fractures (SCHFs), potentially leading to ulnar nerve injury (UNI) and open reduction. We analyzed the correlation between the rotations and UNI or open reduction and then assessed the risk factors associated with these rotations.MethodsData of Wilkins type III lateral flexion SCHFs were collected over a 10-year time period (1 January 2012 to 31 December 2021) in Children's Hospital of Fudan University Anhui Hospital. We defined the rotation of the distal fragment on the coordinate axis as two types, IIIA (X-axis rotation) and IIIB (the rotation of both X- and Y-axes) on X-ray radiography. Demographic data, the incidence of the two-type rotation, odds ratios (ORs) of UNI and open reduction, and risk factors of the rotation of both X- and Y-axes were analyzed.ResultsTotally, 152 patients were found (50 with IIIA vs. 102 IIIB). The UNI rate was 13%, and the open reduction rate was 22%. The UNI rate of the IIIB was five-fold higher than that of the IIIA [OR, 5.143; 95% confidence interval (CI), 1.414–23.125; p = 0.019], and the open reduction rate of the IIIB was nearly five-fold higher than that of the IIIA (OR, 4.729, 95%CI, 1.584–14.495; p = 0.003). In these two types, patients with UNI had a higher risk of open reduction than those without UNI (OR, 9.816; 95%CI, 3.503–27.508; p = 0.001). In the multiple regression analysis, a high level of fracture was identified as a risk factor for the rotation of both X- and Y-axes.ConclusionType IIIB lateral flexion-type SCHFs have higher rates of UNI and open reduction, and a high level of fracture is a risk factor associated with this type.

Objective The incidence of open reduction and internal fixation (ORIF) in flexion-type supracondylar humerus fractures (SCHF) in children is significantly higher than that of extension-type fractures. This study aimed to identify risk factors for ORIF in flexion-type SCHF. Methods One hundred seventy-one patients with Wilkins type III flexion-type SCHF from January 2012 to December 2021 were retrospectively enrolled in a tertiary paediatric hospital. Patients were divided into ORIF group versus closed reduction and internal fixation (CRIF) group. Then, patients data of age, sex, injury side, obesity, deviation of displacement, fracture level, rotation, nerve injury, and delay from injury to surgery were reviewed. Univariate analysis and multivariate logistic regression were used to identify independent risk factors and odds ratios (OR) of ORIF. Results Overall, 171 children with type III flexion-type SCHF were analyzed (average aged 7.9 ± 2.8 years). Displacement was lateral in 151 cases, medial in 20. 20 cases had combined ulnar nerve injury. The failed closed reduction rate was 20%. Univariate analysis indicated age, distal fracture fragment rotation, and ulnar nerve injury were significantly associated with ORIF. ( P = 0.047, P = 0.009, and P = 0.001, respectively). Multivariate logistic regression analysis showed that distal fracture fragment rotation (OR, 3.3; 95%CI:1.1–9.5; P = 0.028) and ulnar nerve injury (OR, 6.4; 95%CI:2.3–18.3; P = 0.001) were independent risk factors; however, the age was not an independent one (OR, 1.5; 95%CI:0.6–3.5; P = 0.397) for ORIF in the Wilkins type III flexion-type SCHF. Conclusion Distal fracture fragment malrotation on initial x-rays and ulnar nerve injury were significant risk factors for ORIF in Wilkins type III flexion-type SCHF. Surgeons should prepare tourniquets or other open reduction instruments when treating these types of fractures. Level of evidence Level IV