Spine to pelvis "T-Construct" using magnetic controlled growing rods in non-walkers neuromuscular early-onset scoliosis: a preliminary study.

BACKGROUNDS: Magnetic controlled growing rods (MCGRs) have been proven to be effective in controlling early onset neuromuscular scoliosis but no study has evaluated the combination with a sacro-bi-iliac construct. The aim of our study is to report surgical management of early onset non-walkers neuromuscular scoliosis correction using MCGRs associated with a sacro-bi-iliac "T-construct" and its mid-term outcomes. Our hypothesis was that this set-up provided well correction of the pelvic obliquity and that this correction was maintained over time. METHODS: A retrospective single-center study was conducted including all consecutive neuromuscular early onset scoliosis who underwent spinopelvic fixation using "T-construct" with two MCGRS. Four millimeters lengthening was performed every 4 months during outpatient clinics sessions. All children had a low-dose biplanar stereoradiography in EOS-Chair at pre/postoperative phase, each outpatient clinic appointment and last follow-up. RESULTS: Eighteen patients were included and 17 analyzed at the last follow-up. The mean age at surgery was 9.5 (range from 5 to 12 years), the mean follow-up was 4,7 years (range from 2.5 to 6.6 years) and 8 patients had a Risser stage above four. The global complication rate was 35% (N = 6/17 patients) including three medical and three mechanical complications related to "T-construct", while the reoperation rate was 18% (N = 2 patients for wound debridement and one for iterative pelvic fixation). Cobb angle and pelvic obliquity were significantly improved by surgery (mean correction was 33.2 ° (55%) and 11 ° (77%) respectively; p < 0.001). At the last follow-up, we noted a loss of frontal Cobb angle correction (p < 0.01) whereas we did not observe any significant loss of pelvic obliquity (p > 0.9). CONCLUSIONS: Although the global complication rate was 35% (half of which are mechanical complications), the treatment combining pelvic T-construct and MCGRs provides satisfactory correction of pelvic obliquity correction, good maintenance in the medium term and may be a procedure to consider for the surgical treatment of early onset neuromuscular scoliosis. LEVEL OF EVIDENCE: IV; Retrospective cohort prognostic study.

Topology, dynamics, and control of a muscle-architected soft arm.

Muscular hydrostats, such as octopus arms or elephant trunks, lack bones entirely, endowing them with exceptional dexterity and reconfigurability. Key to their unmatched ability to control nearly infinite degrees of freedom is the architecture into which muscle fibers are weaved. Their arrangement is, effectively, the instantiation of a sophisticated mechanical program that mediates, and likely facilitates, the control and realization of complex, dynamic morphological reconfigurations. Here, by combining medical imaging, biomechanical data, live behavioral experiments, and numerical simulations, an octopus-inspired arm made of [Formula: see text]200 continuous muscle groups is synthesized, exposing "mechanically intelligent" design and control principles broadly pertinent to dynamics and robotics. Such principles are mathematically understood in terms of storage, transport, and conversion of topological quantities, effected into complex 3D motions via simple muscle activation templates. These are in turn composed into higher-level control strategies that, compounded by the arm's compliance, are demonstrated across challenging manipulation tasks, revealing surprising simplicity and robustness.

Age-dependencies of the electroretinogram in healthy subjects.

OBJECTIVE: The purpose of this study was to evaluate the age-dependency of amplitudes and implicit times in the electroretinograms (ERGs) of healthy individuals and provide clinicians and researchers with a reference for a variety of stimulus paradigms. DESIGN AND METHODS: Full-field electroretinography was conducted on 73 healthy participants aged 14-73 using an extended ISCEV standard protocol that included an additional 9 Hz flicker stimulus for assessing rod function and special paradigms for isolated On-Off and S-cone responses. Correlation coefficients and best-fit regression models for each parameter's age-dependency were calculated. RESULTS: Dark-adapted ERGs, in particular, displayed notable age-related alterations. The attenuation and delay of the b-wave with higher age were most significant in the dark-adapted, rod-driven 0.001 cd s/m2 flash ERG. The age-dependent reduction of the a-wave amplitude was strongest in the standard dark-adapted 3 cd s/m2 flash condition. Cone-driven, light-adapted responses to either flash or flicker stimuli displayed comparatively small alterations at higher age. S-cone function tended to diminish at an early age, but the effect was not significant in the whole population. CONCLUSION: The results suggest that rod and cone function decline at different rates with age, with rods being generally more affected by aging. Nonetheless, response amplitudes displayed a wide variability across the whole sample.

Promising CO2 gas sensor application of zinc oxide nanomaterials fabricated via HVPG technique.

Highly effective gas sensors for detecting a range of hazardous and toxic gases were successfully applied in the present study using Zinc oxide (ZnO) nanomaterials. In this work, the horizontal vapor phase growth (HVPG) technique was perfectly capable of the synthesis of zinc oxide (ZnO) nanomaterials. The effect of the growth time with different dwell times was discussed by comparing the SEM-EDX analysis and photoluminescence characterization of the samples. Magnetic field (AMF) was also incorporated to determine the effect of AMF on the synthesis of ZnO nanomaterials. The results showed that the ZnO nanorods and root-like shapes are formed with more than 5 µm length and a few nm diameters. The optimum parameter showed the sensors are shiner than the less effective sensor when applied. The introduction of an external magnetic field led to a reduced energy band gap by a maximum of 15 %. The non-AMF band gap energy value is observed to be between 3.51 and 3.58 eV, while the value obtained using AMF is found to be between 2.94 and 3.22 eV. During the CO2 gas sensor test, AMF ZnO nanomaterial samples exhibited higher voltage and gradient compared to non-AMF samples.

Soft and Deformable Thermoresponsive Hollow Rod-Shaped Microgels.

Depending on their aspect ratio, rod-shaped particles exhibit a much richer 2D and 3D phase behavior than their spherical counterparts, with additional nematic and smectic phases accompanied by defined orientational ordering. While the phase diagram of colloidal hard rods is extensively explored, little is known about the influence of softness in such systems, partly due to the absence of appropriate model systems. Additionally, investigating higher volume fractions for long rods is usually complicated because non-equilibrium dynamical arrest is likely to precede the formation of more defined states. This has motivated us to develop micrometric rod-like microgels with limited sedimentation that can respond to temperature and reversibly reorganize into defined phases via annealing and seeding procedures. A detailed procedure is presented for synthesizing rod-shaped hollow poly(N-isopropylacrylamide) microgels using micrometric silica rods as sacrificial templates. Their morphological characterization is conducted through a combination of microscopy and light scattering techniques, evidencing the unconstrained swelling of rod-shaped hollow microgels compared to core-shell microgel rods. Different aspects of their assembly in dispersion and at interfaces are further tested to illustrate the opportunities and challenges offered by such systems that combine softness, anisotropy, and thermoresponsivity.

Outcome of distraction-based growing rods at graduation: a comparison of traditional growing rods and magnetically controlled growing rods.

INTRODUCTION: Distraction-based growing rods have been considered as an alternative surgical option for the operative treatment of EOS. TGR has been challenged by MCGR, which is reported to have the advantage of non-invasive lengthening with fewer planned returns to theatre. This study explores the radiographic outcomes, Unplanned Returns to the Operating Room (UPROR) and complication profile of both the procedures at the end of the planned growing rod treatment with either TGR or MCGR. METHODS: We included all the EOS cases from the PSSG database that underwent either TGR or MCGR with spine-based proximal anchors, followed up to the time of graduation. Any crossover or hybrid procedures were excluded. 549 patients (409 TGR and 140 MCGR) were eligible for review. We measured the coronal curve magnitude, Kyphosis, T1-T12, T1-S1 and L1-S1 lengths at 4 time points (before and after the index surgery and before and after the definitive surgery). RESULTS: The TGR group were slightly younger at the time of the index procedure (7 years for TGR vs. 8.5 years for MCGR, p < 0.001). We noted an improvement in all radiological parameters after the growing rod implantation. The spinal lengths increased through the lengthening period, while the coronal curve magnitude and the kyphosis increased. The kyphosis normalized following the final fusion, the coronal curve magnitude reduced further with a further increase in spinal lengths. The final follow-up from the time of the index implantation to the definitive surgery was 5.1 years (IQR 3.8) in TGR and 3.5 years (IQR 1.65) in the MCGR groups. The total number of complications was fewer in the MCGR group. The overall risk of UPROR was lower in the MCGR group and implant breakage was less in the MCGR group by 4.7 times. CONCLUSIONS: This study confirms the equivalence of both the distraction-based growing rods systems from the radiological stand-point, during the lengthening phase and at the time of the definitive surgery. The TGR was more kyphogenic during the lengthening period. The complications and UPROR were fewer in the MCGR groups.

Multi-Rod Posterior Occipitocervical Instrumentation Constructs: A Biomechanical Analysis and Initial Case Series of 10 Patients with Complex Craniocervical Pathology.

BACKGROUND CONTEXT: Stabilization of the occipitocervical (OC) junction with posterior instrumentation plays a vital role in addressing a spectrum of pathologies. Due to limited bone surfaces of the occiput and C1 lamina, achieving union across the OC junction is challenging. PURPOSE: To explore the biomechanics and a clinical series of patients treated with multi-rod constructs across the OC junction using a novel occipital plate with single- and dual-headed, modular tulip heads. STUDY DESIGN/SETTING: Biomechanical analysis and retrospective case series. PATIENT SAMPLE: Adults at a single institution who underwent posterior cervical multi-rod constructs across the OC junction. OUTCOME MEASURES: OC-C4 range of motion (ROM), maximum von Mises stress on the rods, and adjacent segment ROMs and intradiscal parameters. Patient demographics, revision operations, rod breakages, wound complications. METHODS: A validated occiput-cervical finite element (FE) model was used to simulate OC-C4 cervical fixation under multi-directional pure moment loading. A total of 4 rod configurations were simulated: (A) 2-rod-Ti (4.0 mm titanium rods); (B) 2-rod-CoCr (3.5 mm cobalt chrome rods); (C) 3-rods (4.0 mm titanium rods); (D) 4-rods (4.0 mm titanium rods). The aforementioned measures were compared. A retrospective analysis was also performed of adults at a single institution who underwent posterior cervical multi-rod constructs across the OC junction. RESULTS: Biomechanically, lowest primary rod stresses were observed for 3- and 4-rod constructs. Compared to 2-rod-Ti (121.8 MPa), 2-rod-CoCr showed a 43.2% stress increase in the rods, while 3- and 4-rods experienced rod stress reductions of 20% and 23.2%, respectively. No appreciable differences in OC-C4 ROM, C4-5 ROM, and C4-5 discal stresses were found between multi-rod and 2-rod constructs. Maximum occipital and C4 screw stresses were decreased in multi-rod constructs compared to 2-rods, with least stresses noted in the 4-rod construct. Maximum plate stresses were slightly increased in the 4-rod construct compared to 2- and 3-rod fixation, though the forces were largely similar among the constructs. Ten patients (average age 66.4 ± 10.6 years; 8 males) were assessed clinically. Nine of the ten operations were for primary stabilization of pathological fractures and associated craniocervical and/or atlantoaxial instability using 4-rods across the OC junction. At an average follow-up time of 1.58 ± 0.5 years (range, 1 - 2.3 years), there were no instrumentation failures, no adjacent segment failures, and no wound complications. CONCLUSIONS: In this proof-of-concept investigation, multiple rods (3- and 4-rods) across the OC junction using a novel occipital plate with single- and dual-headed, modular tulips was safe and effective in stabilizing the OC junction. Accompanying FE analysis demonstrated that multi-rod constructs decreased primary rod stresses and had lower stresses on occipital and C4 screws compared to 2-rod constructs, while occipital plate stresses were largely similar. Additional clinical studies are needed to confirm these findings and to determine the ultimate utility of multi-rod constructs across the OC junction.

Two-Step Chirality Transfer to Twisted Assemblies: Synergistic Interplay of Chiral and Aggregation Interactions.

Chirality plays a pivotal role in both the origin of life and the self-assembly of materials. However, the governing principles behind chirality transfer in hierarchical self-assembly across multiple length scales remain elusive. Here, we propose a concise and versatile simulation strategy using the patchy particle chain model to investigate the self-assembly of rods interacting through chiral and aggregation interactions. We reveal that chiral interaction possessing an entropic nature, amplifies the fluctuations and twists in the alignment of rods, while aggregation interaction serves as a foundational platform for aggregation and assembly. When both interactions exhibit moderate absolute and relative values, their synergistic interplay facilitates the chirality transfer from rods to assemblies, resulting in the formation of chiral mesoscale ordered structures. Furthermore, we observe a two-step chirality transfer process by monitoring the formation kinetics of the twisted assemblies. This work not only provides a comprehensive insight into chirality transfer mechanisms, but also introduces a versatile mesoscale simulation framework for exploring the role of chirality in hierarchical self-assembly.

A comprehensive numerical approach to coil placement in cerebral aneurysms: mathematical modeling and in silico occlusion classification.

Endovascular coil embolization is one of the primary treatment techniques for cerebral aneurysms. Although it is a well-established and minimally invasive method, it bears the risk of suboptimal coil placement which can lead to incomplete occlusion of the aneurysm possibly causing recurrence. One of the key features of coils is that they have an imprinted natural shape supporting the fixation within the aneurysm. For the spatial discretization, our mathematical coil model is based on the discrete elastic rod model which results in a dimension-reduced 1D system of differential equations. We include bending and twisting responses to account for the coils natural curvature and allow for the placement of several coils having different material parameters. Collisions between coil segments and the aneurysm wall are handled by an efficient contact algorithm that relies on an octree based collision detection. In time, we use a standard symplectic semi-implicit Euler time stepping method. Our model can be easily incorporated into blood flow simulations of embolized aneurysms. In order to differentiate optimal from suboptimal placements, we employ a suitable in silico Raymond-Roy-type occlusion classification and measure the local packing density in the aneurysm at its neck, wall region and core. We investigate the impact of uncertainties in the coil parameters and embolization procedure. To this end, we vary the position and the angle of insertion of the micro-catheter, and approximate the local packing density distributions by evaluating sample statistics.

Rod-Shaped Au@Ce Nano-Platforms for Enhancing Photodynamic Tumor Collaborative Therapy.

Tumor photodynamic therapy (PDT) relies on intratumoral free radicals, while the limited oxygen source and the depletion of tissue oxygen may exacerbate the hypoxia. As the treatment progresses, there will eventually be a problem of insufficient free radicals. Here, it is found that Au@CeO2 nano-rods (Au@Ce NRs), assembled by gold nano-rods (Au NRs) and ceria nanoparticles (CeO2 NPs), can efficaciously absorb near-infrared light (NIR) to promote the release of oxygen and free radicals. Au@Ce NRs exhibit a higher proportion of Ce3+ (Ce2O3) after oxygen release, while Ce3+ is subsequently oxidized to Ce4+ (CeO2) by trace H2O2. Interestingly, Au@Ce NRs re-oxidized by trace H2O2 can re-releasing oxygen and free radicals again upon NIR treatment, achieving oxygenation/oxygen evolution, similar to charging/discharging. This loop maximizes the conversion of limited oxygen source into highly cytotoxic free radicals. As a result, when B16-F10 cells are treated by NIR/Au@Ce NRs, more tumor cells undergo apoptosis, consistent with the higher level of free radicals. Importantly, NIR/Au@Ce NRs successfully suppresses tumor growth and promotes the generation of epidermal collagen fibers in the transplanted tumor model. Therefore, the rod-shaped Au@Ce NRs provide an ideal platform for maximizing the utilization of intratumoral oxygen sources and improving the treatment of melanoma.

Breakdown of Boltzmann-type models for the alignment of self-propelled rods.

Studies in the collective motility of organisms use a range of analytical approaches to formulate continuous kinetic models of collective dynamics from rules or equations describing agent interactions. However, the derivation of these kinetic models often relies on Boltzmann's "molecular chaos" hypothesis, which assumes that correlations between individuals are short-lived. While this assumption is often the simplest way to derive tractable models, it is often not valid in practice due to the high levels of cooperation and self-organization present in biological systems. In this work, we illustrated this point by considering a general Boltzmann-type kinetic model for the alignment of self-propelled rods where rod reorientation occurs upon binary collisions. We examine the accuracy of the kinetic model by comparing numerical solutions of the continuous equations to an agent-based model that implements the underlying rules governing microscopic alignment. Even for the simplest case considered, our comparison demonstrates that the kinetic model fails to replicate the discrete dynamics due to the formation of rod clusters that violate statistical independence. Additionally, we show that introducing noise to limit cluster formation helps improve the agreement between the analytical model and agent simulations but does not restore the agreement completely. These results highlight the need to both develop and disseminate improved moment-closure methods for modeling biological and active matter systems.

Preservation of vision by transpalpebral electrical stimulation in mice with inherited retinal degeneration.

Introduction: The potential neuroprotective and regenerative properties of electrical stimulation (ES) were studied in rhodopsin knockout mice (Rho -/- ), a murine model of inherited retinal degeneration. The study focused on assessing the impact of varying ES frequencies on visual functions and photoreceptor cell survival in Rho -/- mice. Methods: To elucidate the impact of electrical stimulation on cone survival, Rho -/- mice received either sham or transpalpebral ES using biphasic ramp or rectangular waveforms at 100 µA amplitude, starting at six weeks of age. The treatment duration spanned from one to three weeks. The optimal treatment frequency of ES sessions was determined by applying ES every one, two, or three days in three separate groups of Rho -/- mice. The sham group received daily treatments without the application of ES. Results: Our study revealed significant improvement of visual function in Rho -/- mice following daily or every-other-day noninvasive transpalpebral ES, as evidenced by electroretinogram and optomotor response-based visual behavior assays. Concurrently, assessment of outer nuclear thickness and immunohistochemistry for the cone photoreceptor cell marker PNA demonstrated pronounced increases in the survival of rods and cones and improvement in the morphology of the inner and outer segments. Discussion: This study underscores the protective effect of non-invasive ES in rhodopsin knockout-induced retinal degenerative disorders, providing a foundation for developing targeted therapeutic interventions for retinitis pigmentosa.

Current Concepts in the Treatment of Early Onset Scoliosis.

Despite many surgical advances in the treatment of early onset scoliosis (EOS) over the past two decades, this condition remains a challenge to address. While otherwise healthy children can have EOS, many of these patients have complicated comorbidities making proper treatment algorithms extraordinarily difficult. Non-operative measures can be successful when initiated early, but are many times utilized as a delay tactic until growth-friendly operative procedures can be safely performed. This article will summarize the current concepts in the treatment of EOS with a focus on the surgical advances that have recently been made.

Patient-Specific Rods in Adolescent and Adult Spinal Deformity Surgery: A Narrative Review.

Spinal deformity surgery often requires complex surgical interventions that can have a drastic effect on both patient quality of life and functional capacity. Modern-day corrective solutions for these deformities include spinal osteotomies, pedicle screw instrumentation, and dual/multirod constructs. These solutions are efficacious and are currently considered standard practice for spinal surgeons, but they lack individualization. Patient-specific rods (PSRs) are a novel technology that attempts to offer a personalized approach to spinal deformity correction based on preoperative computerized tomography scans. Moreover, PSRs may offer several advantages to conventional rods, which include achievement of desired rod contour angles according to surgical planning alignment goals, reduced operative time, and reduced blood loss. In adolescent idiopathic scoliosis, those instrumented with PSR have observed coronal Cobb reductions up to 74%. In adult spinal deformity, PSRs have offered superior correction in radiographic parameters such as sagittal vertical axis and pelvic incidence minus lumbar lordosis. However, there still remains a paucity of research in this area, mainly in health care expenditure, cost-effectiveness, and longitudinal clinical outcomes. The purpose of this article is to survey the current body of knowledge of PSR instrumentation in both adolescent and adult spinal deformity populations. The current strength, limitations, and future directions of PSRs are highlighted throughout this article.

Surgical Treatment Strategies for Severe and Neglected Spinal Deformities in Children and Adolescents without the Use of Radical Three-Column Osteotomies.

Background: Severe spinal deformity manifests as a pronounced deviation from the normal curvature of the spine in the frontal, sagittal, and horizontal planes, where the coronal plane curvature exceeds 90 degrees and may coincide with hyperkyphotic deformity. The most severe deformities exhibit rigidity, with flexibility below 30%. If left untreated or improperly treated, these deformities can result in serious complications associated with progression of the curvature. A combination of surgical techniques is frequently employed to attain optimal outcomes and minimize the risk of complications. The overall medical condition of the patient, their capacity to endure extensive procedures, the expertise of the surgeon, and the resources available all play significant roles in determining the course of management. A systematic and thorough review of the relevant literature was conducted utilizing a variety of electronic databases. The primary objective of this study was to scrutinize the surgical techniques commonly employed in complex spine surgeries for the management of severe scoliosis without resection vertebral body techniques, with higher potential risk of major complications, including permanent neurological deficit. Conclusions: Halo-gravity traction, halo femoral traction, and all techniques for releases of the spine (anterior, posterior, or combine), as well as thoracoplasty, have demonstrated significant effectiveness in managing severe and rigid idiopathic scoliosis. The combination of several of these methods can lead to optimal alignment correction without the need to perform high-risk techniques involving three-column osteotomies. Surgeons must customize the indications based on factors such as available resources, characteristics of the deformity, and the patient's individual profile. Surgical correction of severe scoliosis without vertebral body resection surgeries decreases the potential risks related to neurological and pulmonary complications while providing significant clinical improvement outcomes. The powerful Ponte osteotomy is indicated for severe scoliosis, curves with poor flexibility, for better restoration of hypokyphosis, and decrease of hyperkyphosis. These corrective techniques combined with HGT or temporary internal distraction rods are recommended as viable options for managing individuals with severe rigid spine deformity characteristics. Therefore, they also should be considered and performed by a proficient surgical team. The presence of neuromonitoring is crucial throughout these procedures.

Nemaline Myopathy With a Compound Heterozygous Mutation: A Case Report.

A class of genetically based congenital myopathies known as nemaline myopathies is defined by the development of nemaline rods within muscle fibers. We present a case involving an eight-year-old boy who presented with a history of delayed motor development, proximal muscle weakness, and neck flexor weakness. Muscle enzymes were normal, and electrophysiological studies revealed a myopathic pattern. Nemaline myopathy (NM) was diagnosed with the help of clinical exome sequencing, which showed a compound heterozygous mutation with a novel variant in the nebulin (NEB) gene.

[Application of polyetheretherketone rod semi-rigid pedicle screw internal fixation in lumbar non-fusion surgery].

OBJECTIVE: To investigate the effect of Polyetheretherketone (PEEK) rod semi-rigid pedicle screw fixation system in lumbar spine non-fusion surgery. METHODS: A total of 74 patients with tow-level lumbar degenerative diseases who underwent surgery from March 2017 to December 2019 were divided into PEEK rod group and titanium rod group. In the PEEK rod group, there were 34 patients, including 13 males and 21 females, aged from 51 to 79 years old with an average of (62.4±6.8) years old;There were 1 patient of L1-L3 segments, 7 patients of L2-L4 segments, 20 patients of L3-L5 segments and 6 patients of L4-S1 segments. In the titanium rod group, there were 40 patients, including 17 males and 23 females, aged from 52 to 81 years old with an average of (65.2±7.3) years old;There were 3 patient of L1-L3 segments, 11 patients of L2-L4 segments, 19 patients of L3-L5 segments and 7 patients of L4-S1 segments. The general conditions of operation, such as operation time, intraoperative blood loss, postoperative drainage was recorded. The visual analogue scale (VAS) for low back pain and Oswestry disability index (ODI) were compared in preoperatively and postoperatively(3 months, 12 months and last follow-up) between two groups. The change of range of motion (ROM) was observed by flexion and extension x-ray of lumbar. RESULTS: All patients successfully completed the operation. The follow-up time ranged from 22 to 34 months with an average of(26.8±5.6) months. The operative time (142.2±44.7) min and intraoperative blood loss(166.5±67.4)ml in PEEK group were lower than those in titanium group [(160.7±57.3) min、(212.8±85.4) ml](P<0.05). There was no significant differences in postoperative drainage between the two groups (P>0.05). At the final follow-up visit, in PEEK group and titanium group VAS of low back pain[(0.8±0.4) points vs (1.0±0.5) points], VAS for leg pain [ (0.7±0.4) points vs (0.8±0.5) points] and ODI [(9.8±1.6)% vs (12.1±1.5)%] were compared with preoperative [ (5.8±1.1) points vs (6.0±1.1)points], [ (7.2±1.7) points vs (7.0±1.6) points], [(68.5±8.9)% vs(66.3±8.2)%] were significantly different(P<0.05). There was no significant difference in VAS scores between the two groups at each postoperative time point (P>0.05). At 3 months after surgery, there was no difference in ODI between the two groups (P>0.05). There were significant differences in ODI between PEEK group and titanium rod group at 12 months [(15.5±2.1)% vs (18.4±2.4)%] and at the last follow-up [(9.8±1.6)% vs (12.1±1.5)%] (P<0.05). The total range of motion (ROM) of lumbar decreased in both groups after surgery. At 12 months after surgery and the last follow-up, the PEEK group compared with the titanium rod group, the total range of motion of lumbar was statistically significant (P<0.05). The range of motion (ROM) of the fixed segments decreased in both groups after surgery. The ROM of the fixed segments in PEEK group decreased from (9.5±4.6)° to (4.1±1.9)° at the last follow-up (P<0.05), which in the titanium rod group was decreased from (9.8±4.3)°to (0.9±0.5)° at the last follow-up (P<0.05). The range of motion (ROM) of upper adjacent segment increased in both groups, there was statistical significance in the ROM of upper adjacent segment between the two groups at 12 months after surgery and the last follow-up, (P<0.05). There was no screw loosening and broken rods in both groups during the follow-up period. CONCLUSION: The PEEK rod semi-rigid pedicle screw internal fixation system used in lumbar non-fusion surgery can retain part of the mobility of the fixed segment, showing comparable short-term clinical efficacy to titanium rod fusion. PEEK rod semi-rigid pedicle screw internal fixation system is a feasible choice for the treatment of lumbar spine degenerative diseases, and its long-term efficacy needs further follow-up observation.

Analysis of the Tensile Properties and Probabilistic Characteristics of Large-Tow Carbon Fiber-Reinforced Polymer Composites.

Large-tow carbon fiber-reinforced polymer composites (CFRP) have great application potential in civil engineering due to their low price, but their basic mechanical properties are still unclear. The tensile properties of large-tow CFRP rods and plates were investigated in this study. First, the tensile properties of unidirectional CFRP rods and plates were studied, and the test results of the relevant mechanical properties were statistically analyzed. The tensile strength of the CFRP rod and plate are 2005.97 MPa and 2069.48 MPa. Second, the surface of the test specimens after failure was observed using a scanning electron microscope to analyze the type of failure and damage evolution process. Finally, the probabilistic characteristics of the mechanical properties were analyzed using normal, lognormal, and Weibull distributions for parameter fitting. Quasi-optimality tests were performed, and a probability distribution model was proposed for the mechanical properties of large-tow CFRP rods and plates.

National study reveals gram negative bacteremia on contemporary pediatric AML protocol.

Since bacteremia complicates childhood Acute myeloid leukemia (AML) patients, we assessed bacteremia rates in Israeli children with de-novo AML. All chemotherapy courses of patients enrolled in NOPHO-DBH-2012 AML protocol were included. Down syndrome, acute promyelocytic leukemia were excluded. Among 69 patients, seven had focal bacterial infections. Of the remaining 62, 77.4% had 1-8 bacteremias. Of 238 chemotherapy courses, 98 (41.2%) had bacteremia: 66 (67.3%) predominantly Gram-negative rods (GNR); 28 (28.6%) Gram-positive cocci. Escherichia coli; followed by Klebsiella were most common. Older age, Arab ethnicity, and presenting white blood cell count were associated with an increased risk of bacteremia in the univariable analysis, but these associations were not confirmed in the multivariable analysis. Mortality was high (9.7%), and bacteremia increased PICU utilization 7-fold half from GNR. Most isolates were sensitive to vancomycin/meropenem (94.7%), but GNR had low sensitivity to quinolones (61.8%). High mortality and morbidity of de-novo AML patients from predominantly GNR bacteremia require specific interventions but limited susceptibility to quinolones hampers prophylaxis.

Minimally Invasive Placement of Pedicle Screws Using Robotic-Assisted Navigation and Magnetically Controlled Growing Rods in a Patient with Early-Onset Scoliosis: Technical Note and Case Report.

Introduction: Early-onset scoliosis (EOS) refers to spinal curvature exceeding ten degrees in the coronal plane in patients under 10 years old. When non-operative management fails to control the curvature, surgical intervention may be indicated. In younger patients, growth-friendly instrumentation may be necessary to allow for continued spinal growth while controlling the curve, which includes magnetically control growing rods (MCGR). This paper is the first description of robotic-assisted navigation in a patient with EOS undergoing MCGR insertion with the minimally invasive placement of pedicle screws. The benefits of a trans-muscular robotic-assisted technique include minimizing the risk of autofusion of the non-instrumented area. Case Report: The 7-year-old female patient with vertebral, anal, cardiac, tracheoesophageal, renal, esophageal, and limb anomalies and a complex medical history, presented with progressive, early-onset syndromic scoliosis. She underwent various surgeries in infancy for imperforate anus, colonic atresia, and malrotation, among other issues. Over time her curve worsened, reaching 71° by age seven. Insertion of MCGR was recommended and successfully performed using robotic-assisted navigation for placement of pedicle screws. Immediately post-operatively, the patients' major curve improved to 15°. She was discharged home without complications on post-operative day 4. Conclusion: This case study exemplifies the success and safety of growth-friendly instrumentation using robotic-assisted navigation for the placement of pedicle screws.