Fine-Tuning the d-Band Center Position of Zinc to Increase the Anti-Tumor Activity of Single-Atom Nanozymes.

The exceptional biocompatibility of Zn-based single-atom nanozymes (SAzymes) has led to extensive research in their application for disease diagnosis and treatment. However, the fully occupied 3d10 electron configuration has seriously hampered the enzymatic-like activity of Zn-based SAzymes. Herein, a B-doped Zn-based SAzymes is fabricated by carbonizing zeolite-like Zn-based boron imidazolate framework at different temperatures (Zn-SAs@BNCx, x = 800, 900, 1000, and 1100 °C). The formed B─N bond yielded a local electric field, which changes the position of the d-band center and improved the oxidation state of Zn by facilitating the electron transfer from Zn to N to B. These changes enhanced the adsorption and activation of H2O2 and O2 by Zn-SAs@BNC1000, increasing the nanozymes' multi-enzyme catalytic activity. B doping led to 24.81-, 32.37-, and 13.98-fold increase in the peroxidase-, oxidase- and catalase-like, respectively, catalytic efficiency (Kcat/Km) of Zn-SAs@BNC1000 when compared with no B doping. In addition, Zn-SAs@BNC1000 showed excellent ability to kill tumor cells both in vitro and in vivo. This study demonstrates that the modulation of the electron configuration of Zn is an effective strategy to develop efficient anti-tumor approaches by boosting the enzymatic activity of Zn-based SAzymes.

Brain-Computer Interface for Patients with Spinal Cord Injury: A Bibliometric Study.

BACKGROUND: Spinal cord injury (SCI) is a debilitating condition with profound implications on patients' quality of life. Recent advancements in brain-computer interface (BCI) technology have provided novel opportunities for individuals with paralysis due to SCI. Consequently, research on the application of BCI for treating SCI has received increasing attention from scholars worldwide. However, there is a lack of rigorous bibliometric studies on the evolution and trends in this field. Hence, the present study aimed to use bibliometric methods to investigate the current status and emerging trends in the field of applying BCI for treating SCI and thus identify novel therapeutic options for SCI. METHODS: We conducted a comprehensive review of the relevant literature on BCI applications for treating SCI published between 2005 and 2024 by using the Web of Science Core Collection database. To facilitate visualization and quantitative analysis of the published literature, we used VOSviewer and CiteSpace software tools. These tools enabled the assessment of co-authorships, co-occurrences, citations, and co-citations in the selected literature, thereby providing an overview of the current trends and predictive insights into the field. RESULTS: The literature search yielded 714 publications from the Web of Science Core Collection database. The findings indicated a significant upward trend in the number of publications, yielding a total of 24,804 citations, with an average citation rate of 34.74 per publication and an H-index of 75. Research contributions were identified from 54 countries/regions, and the United States, China, and Germany emerged as the predominant contributors. A total of 1114 research institutions contributed to the retrieved literature, with Harvard Medical School, Brown University, and Northwestern University producing the highest number of publications. The published literature was predominantly distributed across 258 academic journals, and the Journal of Neural Engineering was the most frequently utilized publication source. Hochberg, Leigh, Henderson, Jaimie, and Collinger were the prominent authors in this field. CONCLUSIONS: In recent years, there has been a steep increase in research on the use of BCI for treating SCI. Existing research focuses on the application of BCI for improving rehabilitation and quality of life of patients with SCI. Interdisciplinary collaboration is the current trend in this field.

Construction of dendritic mesoporous SiO2 supported Cu catalyst for hydrodeoxidation of lignin derivatives.

Chemoselective hydrodeoxygenation (HDO) of lignin derivatives is of great importance in converting biomass into high value-added chemicals. Herein, we report a simple hydrothermal pathway to fabricate a highly active, chemically selective, and reusable catalyst (Cu/DMSN) by loading copper clusters on "dendritic" mesoporous silica nanospheres. Cu/DMSN exhibits exceptional catalytic activity (conversion > 99 %, selectivity > 99 %) in the HDO of vanillin toward 2-methoxy-4-methylphenol under mild conditions (140 °C, 0.5 MPa, 3 h), along with good scalability and a wide range of substrates. The excellent catalytic performance can be owed to the combination of suitable acid site and more exposed metal site. This study provides a new strategy for designing supported metal catalysts for hydrodeoxidation of biomass and its derivatives.

One-Stage Surgical Management for Cervical Pyogenic Spondylodiscitis by Anterior Debridement, Reconstruction, and Instrumentation: A Single-Center Experience.

OBJECTIVE: Surgical treatment is an effective strategy for cervical pyogenic spondylodiscitis (CPS). However, the optimal surgical approach is uncertain. This study was conducted to evaluate the clinical efficacy of debridement, reconstruction, and instrumentation via the anterior-only approach for CPS. METHODS: We retrospectively collected the data of patients with CPS who underwent one-stage anterior debridement, reconstruction, and instrumentation from January 2013 to December 2022. The surgical duration and blood loss volume were analyzed. The Frankel grading classification was used to evaluate the improvement in neurological function. The visual analog scale and Japanese Orthopaedic Association scores were used to evaluate neck pain and functional recovery. The radiological parameters of regional lordosis angle and C2-C7 Cobb angle were used to evaluate the recovery of cervical alignment. C-reactive protein and erythrocyte sedimentation rate were evaluated to assess the control of infection. RESULTS: Totally, 32 patients were eligible. The surgical duration was 118.9 ± 14.3 minutes, and the blood loss volume was 88.4 ± 42.7 mL. Significant improvements in the Frankel grading were observed in patients with neurological deficits. The visual analog scale and Japanese Orthopaedic Association scores significantly improved postoperatively and during follow-up (P < 0.01). The regional lordosis angle significantly increased from 4.0° ± 6.6° preoperatively to 8.4° ± 5.8° at the final follow-up (P < 0.01). The C2-C7 Cobb angle increased from 11.1° ± 7.1° preoperatively to 13.8° ± 7.2° at the final follow-up (P < 0.01). Bony fusion occurred in all patients. C-reactive protein and erythrocyte sedimentation rate significantly decreased postoperatively and returned to normal during follow-up. CONCLUSIONS: One-stage debridement, reconstruction, and instrumentation via the anterior approach is an effective surgical strategy for CPS. In addition to surgery, targeted and prolonged antibiotic therapy is of crucial importance.

Characterizing organophosphate esters and chlorinated paraffins in surface soils affected by diverse e-waste disassembling process in South China: Occurrence, distinct emission, and risk assessment.

E-waste recycling activities are a crucial emission source of organic pollutants, posing potential risks to the surrounding environment and human health. To understand the potential impact related to diverse e-waste dismantling activities, we investigated two categories of popular flame retardants (i.e., organophosphate esters (OPEs) and chlorinated paraffins (CPs) and their resultant possible ecological risk in 53 surface soil samples from Qingyuan, a well-known e-waste recycling region in South China. Varied concentrations of ΣOPEs (20.5-8720 ng/g) and ΣCPs (920-16800 ng/g) were observed at diverse dismantling sites, while relatively low levels of ΣOPEs (6.13-1240 ng/g) and ΣCPs (14.8-2870 ng/g) were found in surrounding soils. These results indicated that primitive e-waste dismantling processes were the primary emission source of OPEs and CPs in the studied area, with e-waste dumping and manual dismantling being the most important emission sources for OPEs and CPs. More importantly, CPs could be degraded/transformed into more toxic intermediates via dechlorination and decarbonization during the burning of e-waste. Furthermore, our results indicated the potential ecological risks posed by OPEs and CPs related to e-waste recycling.

Phosphate Ion-Responsive and Calcium Peroxide-Based Nanomedicine for Bone-Targeted Treatment of Breast Cancer Bone Metastasis.

The treatment of breast cancer bone metastasis is an unresolved clinical challenge, mostly because currently therapeutic approaches cannot simultaneously block the tumor growth and repair the osteolytic bone injuries at the metastatic site. Herein, the study develops a novel nanomedicine to treat breast cancer bone metastasis. The nanomedicine is based on phosphate ion-responsive and calcium peroxide-based nanoparticles carrying the bone-targeting agent zoledronic acid on the surface and loaded with the photosensitizer indocyanine green. Following intravenous administration to a mouse model of breast cancer bone metastasis, the nanoparticles efficiently accumulate at the bone metastasis site, react with free phosphate ions, and form hydroxyapatite nanoaggregates and O2, while releasing the photosensitizer. Hydroxyapatite nanoaggregates elicit the remineralization of the collagenous bone matrix and trigger tumor cell apoptosis. Upon irradiating tumor-bearing legs with an 808 nm laser source, the O2 and free photosensitizer produced 1O2 by the reaction of the nanoparticles with phosphate ions, further boosting the anti-tumor effect. Tumor killing hampers the vicious cycle at the site of bone metastasis, translating to osteolysis blockade and further encouraging the remineralization of bone matrix. This work sheds light on the development of a novel, safe, and efficient approach for the treatment of breast cancer bone metastasis.

FeSA­Ir/Metallene Nanozymes Induce Sequential Ferroptosis­Pyroptosis for Multi­Immunogenic Responses Against Lung Metastasis.

For cancer metastasis inhibition, the combining of nanozymes with immune checkpoint blockade (ICB) therapy remains the major challenge in controllable reactive oxygen species (ROS) generation for creating effective immunogenicity. Herein, new nanozymes with light-controlled ROS production in terms of quantity and variety are developed by conjugating supramolecular-wrapped Fe single atom on iridium metallene with lattice-strained nanoislands (FeSA-Ir@PF NSs). The Fenton-like catalysis of FeSA-Ir@PF NSs effectively produced •OH radicals in dark, which induced ferroptosis and apoptosis of cancer cells. While under second near-infrared (NIR-II) light irradiation, FeSA-Ir@PF NSs showed ultrahigh photothermal conversion efficiency (𝜂, 75.29%), cooperative robust •OH generation, photocatalytic O2 and 1O2 generation, and caused significant pyroptosis of cancer cells. The controllable ROS generation, sequential cancer cells ferroptosis and pyroptosis, led 99.1% primary tumor inhibition and multi-immunogenic responses in vivo. Most importantly, the inhibition of cancer lung metastasis is completely achieved by FeSA-Ir@PF NSs with immune checkpoint inhibitors, as demonstrated in different mice lung metastasis models, including circulating tumor cells (CTCs) model. This work provided new inspiration for developing nanozymes for cancer treatments and metastasis inhibition.

Associations of collagen type 1 α1 gene polymorphisms and musculoskeletal soft tissue injuries: a meta-analysis with trial sequential analysis.

Numerous studies have investigated the role of collagen type 1 α1 (COL1A1) polymorphisms in musculoskeletal soft tissue injuries (MSTIs), yielding conflicting results. This study was designed to synthesize existing evidence and clarify the relationship between COL1A1 polymorphisms and MSTI susceptibility. We conducted a comprehensive literature search using PubMed, Cochrane Library, Web of Science, EMBASE, and Wanfang databases. Associations were assessed using odds ratios (ORs) with 95% confidence intervals (95% CIs) across five genetic models. Subgroup analyses were performed based on ethnicity and injury type. Additionally, trial sequential analysis (TSA) was utilized to assess information size and statistical power. We analyzed a total of 16 articles from 358 retrieved studies, encompassing 2094 MSTI cases and 4105 controls. Our pooled data revealed that individuals with the TT genotype of the rs1800012 polymorphism had a significantly reduced risk of MSTIs (TT vs. GG, OR = 0.53, 95% CI 0.35-0.82, P = 0.004; TT vs. TG + GG, OR = 0.54, 95% CI 0.36-0.80, P = 0.002). Ethnicity-based stratification showed a significant association in Caucasians but not Asians. However, no significant association was observed between the rs1107946 polymorphism and MSTIs, regardless of ethnicity or injury type. TSA indicated that the sample sizes may have been insufficient to yield conclusive results. In conclusion, our study supports the protective effect of the TT genotype of the rs1800012 polymorphism against MSTIs, particularly among Caucasians. However, the rs1107946 polymorphism does not appear to influence MSTI susceptibility.

Occurrence, distribution, and ecological risks of polyhalogenated carbazoles in sediments from Daya Bay and Pearl River Estuary, China.

Polyhalogenated carbazoles (PHCZs) are a group of emerging organic pollutants attracting increasing concern. In this study, 32 sediment samples were collected from the Pearl River Estuary (PRE) and adjacent Daya Bay (DYB) in China and were investigated for the occurrence and distribution of PHCZs. Total concentration of sedimentary PHCZs (∑PHCZs) ranged from 0.79 to 3.08 ng/g in PRE and 0.89 to 1.95 ng/g in DYB, both containing 3,6-dichlorocarbazole as the main component. Higher concentrations of ∑PHCZs were found in the rivers-mouth and inner part of the PRE indicating their main origins from anthropogenic activities. Notably, concentrations of brominated carbazoles (BCZs) gradually increased offshore, which suggests the potential bio-transformation of BCZs under a saline environment. The toxic equivalent of PHCZs was estimated at 0.13-0.34 pg TEQ/g suggesting limited dioxin-like effects on local organisms.

Posterior fixation, anterior debridement and bone grafting in the treatment of thoracic and lumbar tuberculosis in children younger than 3 years of age.

PURPOSE: This study aimed to investigate the clinical outcomes of posterior fixation, combined with one- or two-stage anterior debridement and bone grafting in treating children younger than 3 years of age with thoracic and lumbar tuberculosis. METHODS: This was a retrospective study involving 16 young children with thoracic or lumbar tuberculosis. Surgical data were recorded. Frankel Grade was used to assess neurological function. The regional kyphosis angle was measured to evaluate the deformity correction. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were detected to assess the activity of tuberculosis. Bony fusion and complications were also recorded. RESULTS: The mean operation time was 204.4 ± 41.8 min. The mean estimated blood loss was 126.3 ± 94.4 ml. Preoperative Frankel Grade results indicated five patients with Grade C, six with Grade D, and five with Grade E. At the final follow-up, all patients were in Grade E. Twelve patients were brought back to normal spinal alignment and the rest four patients remained kyphotic. There was an improvement of 29.3° ± 18.3° in regional kyphotic angle postoperatively. And the deformity correction was 27.4° ± 19.1° at the final follow-up. ESR and CRP decreased to a normal range at three months follow-up. Bony fusion was achieved in all patients. None of the cases developed fixation failure, pseudoarthrosis, or tuberculosis recurrence. CONCLUSION: Posterior fixation, combined with one- or two-stage anterior debridement and bone grafting, is a safe and effective surgical strategy for treating young children with thoracic and lumbar tuberculosis.

Modulating the Coordination Environment of Carbon-Dot-Supported Fe Single-Atom Nanozymes for Enhanced Tumor Therapy.

Herein, carbon dot (CD)-supported Fe single-atom nanozymes with high content of pyrrolic N and ultrasmall size (ph-CDs-Fe SAzyme) are fabricated by a phenanthroline-mediated ligand-assisted strategy. Compared with phenanthroline-free nanozymes (CDs-Fe SAzyme), ph-CDs-Fe SAzyme exhibit higher peroxidase (POD)-like activity due to their structure similar to that of ferriporphyrin in natural POD. Aberration-corrected high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure spectroscopy (XAFS) analyses show that metal Fe is dispersed in ph-CDs-Fe SAzyme as single atoms. Steady-state kinetic studies show that the maximum velocity (Vmax ) and turnover number (kcat ) of H2 O2  homolytic cleavage catalyzed by ph-CDs-Fe SAzyme are 3.0 and 6.2 more than those of the reaction catalyzed by CDs-Fe SAzyme. Density functional theory (DFT) calculations show that the energy barrier of the reaction catalyzed by ph-CDs-Fe SAzyme is lower than that catalyzed by CDs-Fe SAzyme. Antitumor efficacy experiments show that ph-CDs-Fe SAzyme can efficiently inhibit the growth of tumor cells both in vitro and in vivo by synergistic chemodynamic and photothermal effects. Here a new paradigm is provided for the development of efficient antitumor therapeutic approaches based on SAzyme with POD-like activity.

Single atom nanozymes for bacterial infection therapy.

Bacterial infection-related diseases continue to pose a significant challenge to global human health. Antibiotic therapy, as a conventional therapeutic strategy, has been extensively employed in clinical settings to treat bacterial infections. However, the effectiveness of these conventional strategies is often impeded by the antimicrobial resistance of bacteria. Consequently, the development of alternative antibacterial agents has emerged as a promising approach to addressing this issue. In recent years, single-atom nanozymes (SAzymes), a novel class of nanocatalytic medicines, have garnered increasing attention due to their numerous advantages, including uniformly dispersed metal active sites, tunable coordination structures, and maximal metal atomic utilization efficiency. To date, a variety of SAzymes have been developed and widely applied in antibacterial therapy. In this minireview, we provide an overview of the latest advances in the synthesis and antibacterial application of different metal-based SAzymes. Furthermore, we discuss the future challenges and opportunities of utilizing SAzymes for bacterial infection treatment. It is our hope that this minireview will contribute to the development of the next generation of SAzyme-based antibacterial agents.

Highly dispersed Co anchored on Ce-doped hydroxyapatite as a dual-functional catalyst for selective hydrogenolysis of 5-hydroxymethylfurfural.

Hydrodeoxygenation (HDO) is an indispensable approach to produce renewable biofuels and value-added chemicals using natural biomass and its derivatives. 2,5-Dimethylfuran (DMF) is considered to be a very promising liquid biofuel, and it can be fabricated by HDO of the biomass derivative 5-hydroxymethylfurfural (HMF). Herein, a highly efficient bifunctional catalyst, Co/HAP(Ce), was fabricated by anchoring highly dispersed Co on Ce-doped hydroxyapatite (HAP(Ce)). Co/HAP(Ce) displayed excellent HDO catalytic activity to convert HMF to DMF, and 99% HMF conversion and 96% DMF selectivity can be obtained under 150 °C, 2 MPa H2 conditions for 5 h. Density functional theory calculations revealed that H2 can be more easily activated by Co/HAP(Ce). Systematic studies confirmed that the high activity of Co/HAP(Ce) can be ascribed to the desired acid-alkali properties, highly dispersed cobalt species and strong metal-support interactions. This research provides a cost effective approach for designing efficient catalysts for HDO of biomass and its derivatives.

Application of cement-augmented pedicle screws in elderly patients with spinal tuberculosis and severe osteoporosis: a preliminary study.

OBJECTIVE: Surgical management of elderly patients with spinal tuberculosis and severe osteoporosis is challenging. Cement-augmented pedicle screws (CAPS) have been specifically designed for elderly patients with osteoporotic spines. Herein, we investigated the feasibility of CAPS applied in elderly patients with spinal tuberculosis and severe osteoporosis. METHODS: We retrospectively analyzed data of patients with spinal tuberculosis and severe osteoporosis between January 2017 and January 2021. Surgical data, including surgical duration and intraoperative blood loss, were recorded. Radiological parameters, such as correction of regional kyphotic angle and screw loosening, were also evaluated. Additionally, visual analog scores (VAS) and Oswestry disability index (ODI) were used to evaluate back pain and functional recovery, respectively. Erythrocyte sedimentation (ESR) and C-reactive protein (CRP) concentrations were detected to assess tuberculosis activity. The presence of complications and fusion rate was also assessed. RESULTS: A total of 15 patients were included in this study. The surgical duration was 263.0 ± 56.2 min, with an average blood loss of 378.7 ± 237.0 ml. The correction of regional kyphotic angle was 12.4° ± 15.0°, and it was well maintained until the final follow-up. The mean VAS decreased from 6.0 ± 1.2 points to 0.5 ± 0.6 points, and ODI reduced from 37.8% ± 7.6% to 8.3% ± 2.8% (P < 0.01). At the final follow-up, ESR and CRP levels were within normal range. Bony fusion occurred in all patients, with an average fusion duration of 8.8 ± 1.5 months. No cases of pedicle screw pullout, screw loosening, or pseudoarthrosis occurred. Tuberculosis recurrence and dissemination were not observed during the follow-ups. CONCLUSIONS: CAPS fixation is an effective and safe technique to achieve solid fixation and favorable clinical outcomes in elderly patients with spinal tuberculosis and severe osteoporosis.

Anaerobic biotransformation of two novel brominated flame retardants: Kinetics, isotope fractionation and reaction mechanisms.

1,2,5,6-tetrabromocyclooctane (TBCO) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), as safer alternatives to traditional brominated flame retardants, have been extensively detected in various environmental media and pose emerging risks. However, much less is known about their fate in the environment. Anaerobic microbial transformation is a key pathway for the natural attenuation of contaminants. This study investigated, for the first time, the microbial transformation behaviors of ß-TBCO and DPTE by Dehalococcoides mccartyi strain CG1. The results indicated that both ß-TBCO and DPTE could be easily transformed by D. mccartyi CG1 with kobs values of 0.0218 ± 0.0015 h-1 and 0.0089 ± 0.0003 h-1, respectively. In particular, ß-TBCO seemed to undergo dibromo-elimination and then epoxidation to form 4,5-dibromo-9-oxabicyclo[6.1.0]nonane, while DPTE experienced debromination at the benzene ring (ortho-bromine being removed prior to para-bromine) rather than at the carbon chain. Additionally, pronounced carbon and bromine isotope fractionations were observed during biotransformation of ß-TBCO and DPTE, suggesting that C-Br bond breaking is the rate-limiting step of their biotransformation. Finally, coupled with identified products and isotope fractionation patterns, ß-elimination (E2) and Sn2-nucleophilic substitution were considered the most likely microbial transformation mechanisms for ß-TBCO and DPTE, respectively. This work provides important information for assessing the potential of natural attenuation and environmental risks of ß-TBCO and DPTE.

Levels and diverse composition profiles of chlorinated paraffins in indoor dust: possible sources and potential human health related concerns.

Chlorinated paraffins (CPs), a group of mixtures with different carbon chain lengths and chlorine contents, are widely used as plasticizers and flame retardants in various indoor materials. CPs could be released from CP-containing materials into the ambient environment and then enter the human body via inhalation, dust ingestion and dermal absorption, resulting in potential effects on human health. In this study, we collected residential indoor dust in Wuhan, the largest city in central China, and focused on the co-occurrence and composition profiles of CPs as well as the resultant human risk via dust ingestion and dermal absorption. The results indicated that CPs with C9-40 were ubiquity in indoor dust with medium-chain CPs (MCCPs, C14-17) as the main components (6.70-495 µg g-1), followed by short-chain CPs (SCCPs, C10-13) (4.23-304 µg g-1) and long-chain (LCCPs, C≥18) CPs (3.68-331 µg g-1). Low levels (not detected-0.469 µg g-1) of very short-chain CPs (vSCCPs, C9) were also found in partial indoor dust. The dominant homolog groups were C9 and Cl6-7 groups for vSCCPs, C13 and Cl6-8 groups for SCCPs, C14 and Cl6-8 groups for MCCPs, and C18 and Cl8-9 groups for LCCPs. Based on the measured concentrations, vSCCPs, SCCPs, MCCPs, and LCCPs posed limited human health risks to local residents via dust ingestion and dermal absorption.

Surgical Treatment for Displaced Odontoid Synchondrosis Fracture: A Retrospective Case Series Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Odontoid synchondrosis fracture is rare, and there is a paucity of literature on its surgical treatments. This case series study analyzed patients treated with C1 to C2 internal fixation with or without anterior atlantoaxial release and discussed the clinical effectiveness of the procedure. METHODS: Data were retrospectively collected from a single-center cohort of patients who had undergone surgical treatments for displaced odontoid synchondrosis fracture. The operation time and blood loss volume were recorded. Neurological function was assessed and classified using the Frankel grades. The odontoid process tilting angle (OPTA) was used to evaluate fracture reduction. Fusion duration and complications were also analyzed. RESULTS: Seven patients (1 boy and 6 girls) were included in the analysis. Three patients underwent anterior release and posterior fixation surgery, and the other 4 underwent posterior-only surgery. The fixation segment was C1 to C2. The average follow-up period was 34.7 ± 8.5 months. The average operation time was 145.7 ± 45.3 min, with an average blood loss volume of 95.7 ± 33.3 mL. The OPTA was corrected from 41.9° ± 11.1° preoperative to 2.4° ± 3.2° at the final follow-up (P < .05). The preoperative Frankel grade of 1 patient was grade C, of 2 patients was grade D, and of 4 patients was grade E. The neurological function of the patients in grade C and grade D recovered to grade E at the final follow-up. None of the patients developed a complication. All the patients achieved odontoid fracture healing. CONCLUSIONS: Posterior C1 to C2 internal fixation with or without anterior atlantoaxial release is a safe and effective method for treating young children with displaced odontoid synchondrosis fracture.