Evaluation of the efficacy of posterior hemivertebrectomy combined with two or more segments fusion.

BACKGROUND: Although early hemivertebra (HV) resection and short fusion (within 4 segments) have been successful in treating congenital HV, there is limited research comparing the outcomes of the shortest-segment fusion (2 segments) versus 3 or 4 segments, particularly in young children. To evaluate the efficacy of posterior hemivertebrectomy combined with two or more segments fusion in children under the age of 10 years with a solitary simple lower thoracic or lumbar HV (T8-L5). METHODS: This retrospective study included patients under the age of 10 with lower thoracic or lumbar solitary simple HV who underwent hemivertebra resection (HVR) and transpedicular short fusion and were divided into HV ± 1 group (2 segment fusion) and HV ± 2 group (3 or 4-segment fusion). The study recorded preoperative, postoperative (1 week), and the latest follow-up radiographic parameters and complications. The results of the coronal and sagittal planes were analyzed, and the main curve, segmental scoliosis curve, compensatory scoliosis curve, segmental kyphosis curve, and trunk shift were compared. RESULTS: The study included 35 patients (15 in the HV ± 1 group and 20 in the HV ± 2 group) with a mean age of 5.26 ± 2.31 years and a mean follow-up of 22.54 months (12-68). The mean preoperative Cobb angle was 32.66° ± 7.339° (HV ± 1) and 29.31°±6.642° (HV ± 2). The final Cobb angle was 10.99°± 7.837° (HV ± 1) and 8.22° ± 4.295° (HV ± 2). The main curve corrected by 72% (HV ± 1), 75% (HV ± 2) postoperatively and 67% (HV ± 1), 72% (HV ± 2) at the final follow-up (P > 0.05). There were no significant differences in the correction of the segmental scoliosis curve, compensatory scoliosis curve, segmental kyphosis curve, and trunk shift between the HV ± 1 and HV ± 2 groups (P > 0.05). The unplanned reoperation rate for HV in the thoracolumbar region (T11-L2) is significantly higher (P = 0.038). CONCLUSION: In the context of solitary simple lower thoracic or lumbar HV (T8-L5), HV ± 1 segment fusion suffices and yields comparable correction outcomes in the midterm period when compared to HV ± 2. The reoperation rate exhibited a statistically significant increase in the thoracolumbar region.

Ego-Lane Index Estimation Based on Lane-Level Map and LiDAR Road Boundary Detection.

Correct ego-lane index estimation is essential for lane change and decision making for intelligent vehicles, especially in global navigation satellite system (GNSS)-challenged environments. To achieve this, we propose an ego-lane index estimation approach in an urban scenario based on particle filter (PF). The particles are initialized and propagated by dead reckoning with inertial measurement unit (IMU) and odometry. A lane-level map is used to navigate the particles taking advantage of topologic and geometric information of lanes. GNSS single-point positioning (SPP) can provide position estimation with meter-level accuracy in urban environments, which can limit drift introduced by dead reckoning for updating the weight of each particle. Light detection and ranging (LiDAR) is a common sensor in an intelligent vehicle. A LiDAR-based road boundary detection method provides distance measurements from the vehicle to the left/right road boundaries, which provides a measurement for importance weighting. However, the high precision of the LiDAR measurements may put a tight constraint on the distribution of particles, which can lead to particle degeneration with sparse particle sets. To deal with this problem, we propose a novel step that shifts particles laterally based on LiDAR measurements instead of importance weighting in the traditional PF scheme. We tested our methods on an urban expressway at a low traffic volume period to ensure road boundaries can be detected by LiDAR measurements at most time steps. Experimental results prove that our improved PF scheme can correctly estimate ego-lane index at all time steps, while the traditional PF scheme produces wrong estimations at some time steps.

Overactivation of the sodium-calcium exchanger and transient receptor potential in anesthesia-induced malignant hyperthermia.

Malignant hyperthermia is a pharmacogenetic disorder, which is an uncommon but frequently fatal intricacy of inhalation anesthesia in man. It causes a quick rise in body temperature to highly irreversible levels, which causes death in around three of four cases. The trigger anesthetics cause an anomalous, continued ascent in myoplasmic calcium levels. Possible mechanisms by which continuous release of sodium, calcium from skeletal muscle plasma membrane and sarcoplasmic reticulum stores respectively can produce the profound hyperthermia are discussed.

An Orthogonal Weighted Occupancy Likelihood Map with IMU-Aided Laser Scan Matching for 2D Indoor Mapping.

An indoor map is a piece of infrastructure associated with location-based services. Simultaneous Localization and Mapping (SLAM)-based mobile mapping is an efficient method to construct an indoor map. This paper proposes an SLAM algorithm based on a laser scanner and an Inertial Measurement Unit (IMU) for 2D indoor mapping. A grid-based occupancy likelihood map is chosen as the map representation method and is built from all previous scans. Scan-to-map matching is utilized to find the optimal rigid-body transformation in order to avoid the accumulation of matching errors. Map generation and update are probabilistically motivated. According to the assumption that the orthogonal is the main feature of indoor environments, we propose a lightweight segment extraction method, based on the orthogonal blurred segments (OBS) method. Instead of calculating the parameters of segments, we give the scan points contained in blurred segments a greater weight during the construction of the grid-based occupancy likelihood map, which we call the orthogonal feature weighted occupancy likelihood map (OWOLM). The OWOLM enhances the occupancy likelihood map by fusing the orthogonal features. It can filter out noise scan points, produced by objects, such as glass cabinets and bookcases. Experiments were carried out in a library, which is a representative indoor environment, consisting of orthogonal features. The experimental result proves that, compared with the general occupancy likelihood map, the OWOLM can effectively reduce accumulated errors and construct a clearer indoor map.

Fast Signals of Opportunity Fingerprint Database Maintenance with Autonomous Unmanned Ground Vehicle for Indoor Positioning.

Indoor positioning technology based on Received Signal Strength Indicator (RSSI) fingerprints is a potential navigation solution, which has the advantages of simple implementation, low cost and high precision. However, as the radio frequency signals can be easily affected by the environmental change during its transmission, it is quite necessary to build location fingerprint database in advance and update it frequently, thereby guaranteeing the positioning accuracy. At present, the fingerprint database building methods mainly include point collection and line acquisition, both of which are usually labor-intensive and time consuming, especially in a large map area. This paper proposes a fast and efficient location fingerprint database construction and updating method based on a self-developed Unmanned Ground Vehicle (UGV) platform NAVIS, called Automatic Robot Line Collection. A smartphone was installed on NAVIS for collecting indoor Received Signal Strength Indicator (RSSI) fingerprints of Signals of Opportunity (SOP), such as Bluetooth and Wi-Fi. Meanwhile, indoor map was created by 2D LiDAR-based Simultaneous Localization and Mapping (SLAM) technology. The UGV automatically traverse the unknown indoor environment due to a pre-designed full-coverage path planning algorithm. Then, SOP sensors collect location fingerprints and generates grid map during the process of environment-traversing. Finally, location fingerprint database is built or updated by Kriging interpolation. Field tests were carried out to verify the effectiveness and efficiency of our proposed method. The results showed that, compared with the traditional point collection and line collection schemes, the root mean square error of the fingerprinting-based positioning results were reduced by 35.9% and 25.0% in static tests and 30.0% and 21.3% respectively in dynamic tests. Moreover, our UGV can traverse the indoor environment autonomously without human-labor on data acquisition, the efficiency of the automatic robot line collection scheme is 2.65 times and 1.72 times that of the traditional point collection and the traditional line acquisition, respectively.

Performance Analysis of BDS Medium-Long Baseline RTK Positioning Using an Empirical Troposphere Model.

For GPS medium-long baseline real-time kinematic (RTK) positioning, the troposphere parameter is introduced along with coordinates, and the model is ill-conditioned due to its strong correlation with the height parameter. For BeiDou Navigation Satellite System (BDS), additional difficulties occur due to its special satellite constellation. In fact, relative zenith troposphere delay (RZTD) derived from high-precision empirical zenith troposphere models can be introduced. Thus, the model strength can be improved, which is also called the RZTD-constrained RTK model. In this contribution, we first analyze the factors affecting the precision of BDS medium-long baseline RTK; thereafter, 15 baselines ranging from 38 km to 167 km in different troposphere conditions are processed to assess the performance of RZTD-constrained RTK. Results show that the troposphere parameter is difficult to distinguish from the height component, even with long time filtering for BDS-only RTK. Due to the lack of variation in geometry for the BDS geostationary Earth orbit satellite, the long convergence time of ambiguity parameters may reduce the height precision of GPS/BDS-combined RTK in the initial period. When the RZTD-constrained model was used in BDS and GPS/BDS-combined situations compared with the traditional RTK, the standard deviation of the height component for the fixed solution was reduced by 52.4% and 34.0%, respectively.

2D LiDAR SLAM Back-End Optimization with Control Network Constraint for Mobile Mapping.

Simultaneous localization and mapping (SLAM) has been investigated in the field of robotics for two decades, as it is considered to be an effective method for solving the positioning and mapping problem in a single framework. In the SLAM community, the Extended Kalman Filter (EKF) based SLAM and particle filter SLAM are the most mature technologies. After years of development, graph-based SLAM is becoming the most promising technology and a lot of progress has been made recently with respect to accuracy and efficiency. No matter which SLAM method is used, loop closure is a vital part for overcoming the accumulated errors. However, in 2D Light Detection and Ranging (LiDAR) SLAM, on one hand, it is relatively difficult to extract distinctive features in LiDAR scans for loop closure detection, as 2D LiDAR scans encode much less information than images; on the other hand, there is also some special mapping scenery, where no loop closure exists. Thereby, in this paper, instead of loop closure detection, we first propose the method to introduce extra control network constraint (CNC) to the back-end optimization of graph-based SLAM, by aligning the LiDAR scan center with the control vertex of the presurveyed control network to optimize all the poses of scans and submaps. Field tests were carried out in a typical urban Global Navigation Satellite System (GNSS) weak outdoor area. The results prove that the position Root Mean Square (RMS) error of the selected key points is 0.3614 m, evaluated with a reference map produced by Terrestrial Laser Scanner (TLS). Mapping accuracy is significantly improved, compared to the mapping RMS of 1.6462 m without control network constraint. Adding distance constraints of the control network to the back-end optimization is an effective and practical method to solve the drift accumulation of LiDAR front-end scan matching.

A Geometry-Based Cycle Slip Detection and Repair Method with Time-Differenced Carrier Phase (TDCP) for a Single Frequency Global Position System (GPS) + BeiDou Navigation Satellite System (BDS) Receiver.

As the field of high-precision applications based on carriers continues to expand, the development of low-cost, small, modular receivers and their application in diverse scenarios and situations with complex data quality has increased the requirements of carrier-phase data preprocessing. A new geometry-based cycle slip detection and repair method based on Global Position System (GPS) + BeiDou Navigation Satellite System (BDS) is proposed. The method uses a Time-differenced Carrier Phase (TDCP) model, which eliminates the Inner-System Bias (ISB) between GPS and BDS, and it is conducive to the effective combination of GPS and BDS. It avoids the interference of the noise of the pseudo-range with cycle slip detection, while the cycle slips are preserved as integers. This method does not limit the receiver frequency number, and it is applicable to single-frequency data. The process is divided into two steps to detect and repair cycle slip. The first step is cycle slip detection, using the Improved Local Analysis Method (ILAM) to find satellites that have cycle slips; The second step is to repair the cycle slips, including estimating the float solution of changes in ambiguities at the satellites that have cycle slips with the least squares method and the integer solution of the cycle slips by rounding. In the process of rounding, in addition to the success probability, a decimal test is carried out to validate the result. Finally, experiments with filed test data are carried out to prove the effectiveness of this method. The results show that the detectable cycle slips number with GPS + BDS is much greater than that with GPS. The method can also detect the non-integer outliers while fixing the cycle slip. The maximum decimal bias in repair is less than that with GPS. It implies that this method takes full advantages of multi-system.

[Effect of Osteoking on Bone Mineral Density and Dickkopf-1 Protein Levels in Rabbits with Osteoporotic Fracture].

OBJECTIVE: To explore the effect of Osteoking on bone mineral density (BMD) and serum Dickkopf-1 (DKK-1) protein levels in rabbits with osteoporotic fracture (OPF). METHODS: Totally 45 female Japanese big-ear rabbits were randomly divided into the treatment group, the model group, and the blank control group (as the control group), 15 in each group. Bilateral ovaries were ectomized for 24 weeks in the treatment group and the model group. Their left radial factures were induced after confirmed osteoporosis. Rabbits in the treatment group were administered with Osteoking by gastrogavage, once per two days. Equal volume of normal saline was given to rabbits in the model group. The general BMD and serum DKK-1 protein levels were detected before ovariectomy, at week 24 and 48 after ovariectomy. RESULTS: There was significant difference in the general BMD at week 24 after ovariectomy between the model group and the control group, and it was lower in the model group. Compared with the model group, the general BMD significantly increased and serum DKK-1 protein levels significantly decreased in the treatment group after intervention. Serum DKK-1 protein levels were significantly lower after intervention than before intervention in the treatment group. CONCLUSION: Osteoking could improve the BMD of OPF rabbits, and reduce their serum DKK-1 protein levels as well.

[Experimental study of repairing severe ligament injury with transgenetic bone mesenchymal stem cells].

OBJECTIVE: To evaluate the efficacies of transgenetic bone mesenchymal stem cells (BMSCs) carring basic fibroblast growth factor (bFGF) gene on repairing severe ligament injury. METHODS: The genes of bFGF and enhanced green fluorescent protein (eGFP) were transfected into BMSCs through adenovirus vector. According to different cell transplantations, the operated rabbits were divided into 3 groups of transgenetic BMSCs, BMSCs and no cells. And group 4 was normal ligament group. The distribution of transgenetic BMSCs in ligament injury area, the expression of bFGF and ligament specific extracellular matrix, i.e. type I collagen, type III collagen, fibronectin, alpha-smooth muscle actin and vimentin, histology and biomechanics of ligament healing were recorded at different timepoints. RESULTS: The transgenetic BMSCs could be observed in injury area within one month. The expression of bFGF in the transgenetic BMSCs group was significantly higher than that in the control groups at Days 3-14 (P < 0.001) and peaked at Day 7. In the transgenetic BMSCs group, the gene expression of ligament specific extracellular matrix was significantly higher than that in the control groups within one month (P < 0.001). And immunohistochemistry showed strong positive expression. After 3 months, in group 1, hematoxylin and eosin staining showed the arrangement and density of collagen fibers of healing area were better than that in the control groups. And biomechanical testing showed that tensile load were stronger than that in the control groups (P < 0.05). CONCLUSION: Transgenetic BMSCs carrying bFGF gene can obviously promote ligament injury healing and increase ligament healing strength.

Comprehensive analysis of 2097 patients with dystrophinopathy based on a database from 2011 to 2021.

BACKGROUND: An increasing number of clinical trials for new therapeutic strategies are underway or being considered for dystrophinopathy. Having detailed data on the natural progression of this condition is crucial for assessing the effectiveness of new drugs. However, there's a lack of data regarding the long-term data on the natural course and how it's managed in China. In this study, we offer a comprehensive overview of clinical and molecular findings, as well as treatment outcomes in the Chinese population. METHODS: Institutional data on all patients with dystrophinopathy from August 2011 to August 2021 were retrospectively reviewed. The data included geographic distribution, age at diagnosis, molecular findings, and treatment options, such as corticosteroids, cardiac interventions, and clinical outcomes. RESULTS: In total, 2097 patients with dystrophinopathy, including 1703 cases of Duchenne muscular dystrophy (DMD), 311 cases of Becker muscular dystrophy (BMD), 46 cases of intermediate muscular dystrophy (IMD), and 37 cases categorized as "pending" (individuals with an undetermined phenotype), were registered in the Children's Hospital of Fudan University database for dystrophinopathy from August 2011 to August 2021. The spectrum of identified variants included exonic deletions (66.6%), exonic duplications (10.7%), nonsense variants (10.3%), splice-site variants (4.5%), small deletions (3.5%), small insertions/duplications (1.8%), and missense variants (0.9%). Four deep intronic variants and two inversion variants were identified. Regarding treatment, glucocorticoids were administered to 54.4% of DMD patients and 39.1% of IMD patients. The median age at loss of ambulation was 2.5 years later in DMD patients who received glucocorticoid treatment. Overall, one cardiac medicine at least was prescribed to 7.4% of DMD patients, 8.3% of IMD patients, and 2.6% of BMD patients. Additionally, ventilator support was required by four DMD patients. Eligibility for exon skipping therapy was found in 55.3% of DMD patients, with 12.9%, 10%, and 9.6% of these patients being eligible for skipping exons 51, 53, and 45, respectively. CONCLUSIONS: This is one of the largest studies to have evaluated the natural history of dystrophinopathy in China, which is particularly conducive to the recruitment of eligible patients for clinical trials and the provision of real-world data to support drug development.

Factors associated with postoperative muscle reconnection in children's congenital muscular torticollis.

Background: In prior studies, there has been no report of clinical observation of postoperative reconnection of the sternocleidomastoid muscle (SCM) in children with congenital muscular torticollis (CMT). Therefore, the objective of this study is to investigate the factors associated with postoperative reconnection of the SCM in children with CMT, and to provide clinical evidence. Methods: A retrospective study was conducted, wherein 83 CMT children without any missing data were followed up from November 2019 to June 2021. The age at the time of surgery, sex, preoperative and postoperative follow-up duration, laterality, neck mass history, preoperative physical therapy history, and severity type were recorded. The severity classification of CMT was based on clinical features and ultrasound images of SCM. The postoperative reconnection of SCM was measured. Results: Out of 83 patients, ten had postoperative reconnection. The rate of postoperative reconnection of SCM in children with CMT who had undergone unipolar SCM release surgery was 18.994 times higher than in patients who had not undergone such surgery. This difference was statistically significant [odds ratio (OR) =18.994, 95% confidence interval (CI): 1.583 to 227.897, P=0.020]. Conclusions: The history of SCM release surgery in CMT children can predict the postoperative reconnection of SCM, which will aid in determining the optimal surgical approach for recurrent CMT patients.

Self-assembly nanoparticle based tripetaloid structure arrays as surface-enhanced Raman scattering substrates.

This paper reports a novel highly ordered tripetaloid structure array (TPSA) which performs very well as an active surface-enhanced Raman scattering (SERS) substrate. The TPSA is easily fabricated by anisotropic etching of a self-assembly silica-nanoparticle bilayer and a subsequent metal deposition step, with notable uniformity and reproducibility. Electromagnetic simulation indicates that the narrow inter-gaps and edge protrusions in the TPSA act as hot spots. In addition, the peak electromagnetic field intensity in the inter-gaps changes slightly and periodically as the polarization of the incident light varies from 0° to 360°. SERS experiments show that the SERS enhancement factor (EF) of a Au-film-covered TPSA is 12 times higher than that of regular Au-film-over-nanoparticles, and not sensitive to the polarization of the incident light. The spatially averaged EF of the TPSA is as high as 5.7 × 10(6), and the local EF of its hot spots is much higher.

Effect of acellular nerve scaffold containing human umbilical cord-derived mesenchymal stem cells on nerve repair and regeneration in rats with sciatic nerve defect.

Background: The aim of the present study was to investigate the effect of acellular nerve scaffold (ANS) containing human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on nerve repair and regeneration in rats with sciatic nerve defect. Methods: Sciatic nerve trunks were removed from 6 female Sprague-Dawley (SD) rats, and ANS was prepared by lyophilization + enzymatic method and divided into A, B, C, D and E groups according to different treatment times. hUC-MSCs were isolated from the collected umbilical cords and cultured, and then ANS-hUC-MSCs complexes were made. The other 24 adult female SD rats were randomly divided into the control, autograft, ANS, and ANS-hUC-MSCs groups, and a rat model of sciatic nerve defect was established. Hematoxylin-eosin (HE) staining, Luxol fast blue (LFB) staining, Masson staining, and scanning electron microscopy were used to observe the morphology and tissue structure of ANS. The performance of ANS was evaluated by mechanical detection, and hydroxyproline (HYP) content was evaluated using a biochemical kit. Flow cytometry was adopted to detect the levels of hUC-MSCs surface antigens CD29, CD44, and CD34, as well as electrophysiological detection and muscle wet weight recovery rate for measuring rat muscle performance. Results: ANS was prepared according to group A method and had good mechanical properties, with less residues of cells and myelin, and higher HYP content, indicating that this scaffold had the best performance. ANS-hUC-MSCs significantly reduced myelin injury in the sciatic nerve, and increased axonal regeneration, effectively improving sciatic nerve injury in rats. In addition, ANS-hUC-MSCs significantly increased compound muscle action potential (CMAP), nerve conduction velocity (NCV), and muscle wet weight, and reduced muscle atrophy. Conclusions: ANS containing hUC-MSCs can promote nerve repair and regeneration in rats with sciatic nerve defects.

Learning Curve of Closed Reduction and Internal Fixation for Supracondylar Fractures of the Humerus in Children.

Background: This study aimed to identify the threshold for success in supracondylar humeral fracture surgery by describing the learning curve for beginners and exploring the relationship between the learning curve and the prognosis of supracondylar fractures of the humerus. Methods: Surgical information was collected of the first 100 humeral fractures treated by four pediatric orthopedic surgeons. The relationship between operation time, wire placement success rate, and surgical experience was determined using the restricted cubic strip (RCS). The inflection point in the curve and other risk factors that may affect fracture prognosis were collected and subjected to multiple logistic regression to clarify the relationship between the learning curve and prognosis of supracondylar fractures of the humerus. After the training, the four fresh surgeons were interviewed in the form of questionnaires to get feedback from the trainees. Results: A total of 400 supracondylar fractures of the humerus from four pediatric orthopedists were included in the study. On an RCS analysis, 65 surgical experiences were the inflection point of the learning curve. Before and after these 65 surgical experiences, there were significant differences in the patients' anatomical reduction (186 vs. 122, P < 0.001), conversion to incision (33 vs. 6, P = 0.008), and supervising physician guidance (28 vs. 2, P < 0.001). In the multiple logistic regression analysis, functional recovery after supracondylar fractures of the humerus was significantly associated with surgical experience, intraoperative conversion to incision, and post-operative infection. Four surgeons and a supervisor were interviewed. They believed that self-confidence establishment requires the experience accumulation of about 30 operations. The most critical surgical technique is the reduction of fractures. Conclusions: Although the accumulated experience of 30 operations can establish the self-confidence of trainers, fresh surgeons must accumulate experience with 65 operations to master closed reduction and internal fixation for supracondylar fractures. Surgical experience significantly impacts the post-operative recovery of patients with fractures. Level of Evidence: Level III.

Successful Closed Reduction of Atlantoaxial Rotatory Fixation in Children-A Retrospective Study of 30 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To review our treatment experience and to investigate the process of this disease. METHODS: Clinical data of AARF patients, who received closed reduction, was retrospectively reviewed. Patients were divided into 2 groups according to the length of delay (Group I: 1 month ≤ delayed time < 3 months), Group II (delayed time < 1 months). The correlation between the length of delayed time and clinical recovery (CR), radiological recovery (RR), and total recovery time were measured. The atlantodental interval (ADI), lateral mass-dens interval (LDI) and lateral joint space (LJS) were compared at admission and final follow-up. RESULTS: 30 children (12 girls and 18 boys) with AARF had received conservative treatment. The mean age at initial treatment was 8.13-year-old, ranging from 5 to 14. The mean follow-up time was 26.93 months (range, 6-87 months). The average length of delayed time was 28.53 days (range, 2-80 days). When the LDI, LJS, and ADI differences are compared at admission and the final visit, the differences are reduced significantly on LDI and LJS. A positive correlation is observed between the length of the delay and CR time and total recovery time (r = 0.63, p = 0.00 and r = 0.47, p = 0.01) respectively. CONCLUSIONS: Pediatric AARF patients who have a delay time < 3 months can be treated with closed reduction successfully. The longer the delayed time, the longer the traction time, but the cervical collar time is almost the same. The LDI and LJS on the anteroposterior of X-rays are convenient to estimate the progress of this condition during the treatment.

Posterior Focal Curettage and Spine Stability Reconstruction by Temporary Pedicle Screw Fixation in Children With Collapsed Vertebrae due to Eosinophilic Granuloma.

STUDY DESIGN: Retrospective case series. OBJECTIVES: To evaluate the efficacy of growth-preserving posterior spinal column reconstruction surgery in children with collapsed vertebral eosinophilic granuloma (EG). METHODS: We retrospectively reviewed 15 confirmed cases of vertebral EG who met the inclusion and exclusion criteria from March 2015 to March 2018 in our hospital. The recovery of diseased vertebrae was assessed. RESULTS: The cases were composed of 11 males and 4 females with a mean age of 74.3 ± 38.8 months. Nine cases presented with thoracic vertebral destruction, 6 cases with lumbar vertebral destruction. Under Garg's classification, 10, 3 and 2 cases were classified as Grade IIA, IB and IIB lesions, respectively. All patients had mild to moderate night-aggravated back pain and recovered at 1-week after surgery. Three patients had Frankel D neurologic symptoms and recovered at 1-week, 1-week and 4-weeks after surgery, respectively. Follow-up time after surgery ranged from 1.9 years to 4.5 years, with a mean of 2.9 years. The median vertebral height at 12 months after surgery was significantly higher than the preoperative height. Furthermore, the vertebral heights of all diseased vertebrae displayed significant recovery trends at 3, 6 and 12 months after surgical treatment. The percentages of vertebral height recovery to references at 12 months after surgery ranged from 34.7% to 92.5%, with an average of 71.2%. CONCLUSIONS: In children with collapsed vertebral EGs, active surgical treatment is necessary to retain the ability to restore height and to reconstruct the spine stability.

Highly-ordered, 3D petal-like array for surface-enhanced Raman scattering.

Despite the great potential of the application of surface-enhanced Raman scattering (SERS), the difficulty in fabricating suitable SERS substrates is still a problem. Based on the self-assembly of silica nanoparticles, a simple method is here proposed to fabricate a highly-ordered, 3D, petal-like arrayed structure (3D PLAS) that serves as a promising SERS substrate for both its high reproducibility and enormous SERS enhancement. Such a novel structure is easily achieved by anisotropically etching a self-assembly bilayer of silica nanoparticles, followed by metal deposition. The SERS performance of the 3D PLAS and its relationship with the main parameters, including the etching time, the diameter of silica nanoparticles, and the deposited metal film, are characterized using 632.8 nm incident light. With Rhodamine 6G as a probe molecule, the spatially averaged SERS enhancement factor is on the order of 5 × 10(7) and the local enhancement factor is much higher, both of which can be improved further by optimizing the parameters.

A cross-sectional study on the impact of the prevention and control response of the COVID-19 pandemic on minor's orthopedic trauma in Shanghai.

BACKGROUND: The Chinese government has taken strong prevention and control measures against the COVID-19 pandemic. Although the pandemic is far from over, it has been effectively controlled in China. The outbreak of COVID-19 pandemic provides an opportunity to study the influence of governmental prevention and control response on orthopedic trauma in minors. METHODS: We collected and reviewed data and information on minor's orthopedic trauma from 1 January to 30 June of the past three year (2018, 2019 and 2020). The data were divided according to the time of prevention and control response level in 2020 (the first level response is from January 24 to March 22, the second level response is from March 23 to May 7, and the third level response is May 8 to now). By comparing the relevant data from orthopedic emergency and operating rooms from the past three years, the influence of governmental pandemic prevention measures on orthopedic trauma in minors was analyzed. RESULTS: A total of 36,301 minors were included in the study cohort. Before the prevention and control response, the data of the orthopedic emergency department of National Children Medical Center (Shanghai) in 2020 was the same as the previous two years. The condition of children undergoing surgery at the time of injury is significantly different under different levels of prevention and control response. Under the first-level response, the number of fractures, open injuries, radial head subluxation, and surgery were significantly reduced, and the severity of patients with surgery was also significantly reduced. Under the second-level response, the number of operations began to increase, and the severity of the disease also began to rise. Under the third-level response control, the number of fractures, open injuries, and operations have returned to the levels of the previous two years. The severity of the operation has also returned to its previous level. The number of subluxations of the radial head is still different from before. CONCLUSION: The prevention and control response for the pandemic of COVID-19 can reduce the incidence of orthopedic trauma in minors by strengthening the guardian's care and restricting children's outdoor activities. With the control of the pandemic, the amount of orthopedic trauma in minors will not be affected by low-level prevention and control.

Recommendations for control and prevention of infections for pediatric orthopedics during the epidemic period of COVID-19.

The outbreak of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged and spread rapidly throughout the world. As of February 29, 2020, 79 389 cases of COVID-19 have been reported, and the outbreak is linked to 2838 deaths. The population is generally susceptible to the disease, and differences in incubation periods after infection exist among individuals. These two aspects of COVID-19 pose significant challenges to pediatric orthopedic diagnosis and treatment. As a dedicated center for managing pediatric cases of SARS-CoV-2 in Shanghai, our hospital has mobilized all branches and departments to undertake joint actions for scientific prevention and control, precise countermeasure and comprehensive anti-epidemic efforts. Combined with our experience, we have consulted the relevant national regulations and the latest research advances and have formulated the prevention and control measures of SARS-CoV-2 infection, including outpatient, emergency, inpatient and surgical cares, for clinical practices of pediatric orthopedics according to the physicochemical properties of SARS-CoV-2. It may serve as practical references and recommendations for managing SARS-CoV-2 infection in other pediatric specialties and in other hospitals.