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Abstract Objective: To investigate the predictive ability of the MRI-based vertebral bone quality (VBQ) score for pedicle screw loosening following instrumented transforaminal lumbar interbody fusion (TLIF). Methods: Data from patients who have received one or two-level instrumented TLIF from February 2014 to March 2015 were retrospectively collected. Pedicle screw loosening was diagnosed when the radiolucent zone around the screw exceeded 1 mm in plain radiographs. The T1-weighted MRI sagittal images were used for calculation of the VBQ score. The score was calculated with the median signal intensity value of L1 to L4 divided by the signal intensity value of cerebrospinal fluid at the L3 level. Univariate analysis and multivariate binary logistic regression analysis were performed. Receiver operating characteristic curve analysis assessed the predictive ability of the VBQ score on screw loosening. Results: Among the included 211 patients, 75 of them (35.55%) had pedicle screw loosening at the 24 month follow-up. Multivariable logistic regression analyses demonstrated that higher VBQ score (OR: 27.887 ± 0.514 ,95% CI: 10.189–76.326), male sex (female to male 0.323 ± 0.483, 0.126–0.833), and longer fusion length (2.578 ± 0.545, 1.166–5.701) were significant influencing factors for pedicle screw loosening. The VBQ score significantly predicted screw loosening with an accuracy of 78.9%. Conclusions: A higher VBQ score was an independent risk factor for pedicle screw loosening following instrumented TLIF. The MRI-based VBQ score showed good predictive ability for screw loosening and could be used as an alternative option for preoperative bone quality evaluation.

Abstract Objective Combining oblique lumbar interbody fusion (OLIF) with posterior pedicle screw fixation (PPSF) has been proposed to reduce cage subsidence, especially in osteoporotic spines. Recently, anterolateral screw-rod fixation has gained interest as it allows direct pathology observation and avoids a posterior approach. However, controversies exist between anterolateral screw fixation systems and traditional PPSF due to variations in osteoporotic vertebral mineral density, screw fixation positions, and fixation methods (bicortical vs. unicortical). This study aimed to investigate the biomechanical impact of fixation position and method in osteoporotic spine. Methods Seventy-two fresh‑frozen porcine vertebrae (L1–6) were decalcified using 0.5 M EDTA and divided into two groups based on fixation method: bicortical or unicortical. Six groups for each method were created according to the screw position in the lateral vertebral body, with six specimens in each group: anterior, central, and posterior in the middle body and para-endplate regions. Correlations among screw position, fixation method and axial pullout strength were analyzed. Results A 4-week decalcification process, bone mineral density in the porcine vertebrae decreased to approximately 48% (p

This study proposes a fault diagnosis method for harmonic drive systems based on multi-sensor data fusion and the gravitational search algorithm (GSA). As a critical component in robotic arms, harmonic drives are prone to failures due to wear, less grease, or improper loading, which can compromise system stability and production efficiency. To enhance diagnostic accuracy, the research employs wavelet packet decomposition (WPD) and empirical mode decomposition (EMD) to extract multi-scale features from vibration signals. These features are subsequently fused, and GSA is used to optimize the high-dimensional fused features, eliminating redundant data and mitigating overfitting. The optimized features are then input into a support vector machine (SVM) for fault classification, with K-fold cross-validation used to assess the model’s generalization capabilities. Experimental results demonstrate that the proposed diagnosis method, which integrates multi-sensor data fusion with GSA optimization, significantly improves fault diagnosis accuracy compared to methods using single-sensor signals or unoptimized features. This improvement is particularly notable in multi-class fault scenarios. Additionally, GSA’s global search capability effectively addresses overfitting issues caused by high-dimensional data, resulting in a diagnostic model with greater reliability and accuracy across various fault conditions.

Abstract Chorus waves are intense electromagnetic emissions critical in modulating electron dynamics. In this study, we perform two‐dimensional particle‐in‐cell simulations to investigate self‐consistent wave‐particle interactions with oblique chorus waves. We first analyze the electron dynamics sampled from cyclotron and Landau resonances with waves, and then quantify the advection and diffusion coefficients through statistical studies. It is found that phase‐trapped cyclotron resonant electrons satisfy the second‐order resonance condition and gain energy from waves. While phase‐bunched cyclotron resonant electrons cannot remain in resonance for long periods. They transfer energy to waves and are scattered to smaller pitch angles. Landau resonant electrons are primarily energized by waves. For both types of resonances, advection coefficients are greater than diffusion coefficients when the wave amplitude is large. Our study highlights the important role of advection in electron dynamics modulation resulting from nonlinear wave‐particle interactions.

Abstract Chorus subpackets are the wave packets with modulated amplitudes in chorus waves, commonly observed in the magnetospheres of Earth and other planets. Nonlinear wave‐particle interactions have been suggested to play an important role in subpacket formation, yet the corresponding electron dynamics remain not fully understood. In this study, we have investigated the electron trapping through cyclotron resonance with subpackets, using a self‐consistent general curvilinear plasma simulation code simulation model in dipole fields. The electron trapping period has been quantified separately through electron dynamic analysis and theoretical derivation. Both methods indicate that the electron trapping period is shorter than the subpacket period/duration. We have further established the relation between electron trapping period and subpacket period through statistical analysis using simulation and observational data. Our study demonstrates that the nonlinear electron trapping through cyclotron resonance is the dominant mechanism responsible for subpacket formation.

Abstract A 2‐D GCPIC simulation in a dipole field system has been conducted to explore the excitation of oblique whistler mode chorus waves driven by energetic electrons with temperature anisotropy. The rising tone chorus waves are initially generated near the magnetic equator, consisting of a series of subpackets, and become oblique during their propagation. It is found that electron holes in the wave phase space, which are formed due to the nonlinear cyclotron resonance, oscillate in size with time during subpacket formation. The associated inhomogeneity factor varies accordingly, giving rise to various frequency chirping in different phases of subpackets. Distinct nongyrotropic electron distributions are detected in both wave gyrophase and stationary gyrophase. Landau resonance is found to coexist with cyclotron resonance. This study provides multidimensional electron distributions involved in subpacket formation, enabling us to comprehensively understand the nonlinear physics in chorus wave evolution.

Formosan languages, spoken by the indigenous peoples of Taiwan, have unique roles in the reconstruction of Proto-Austronesian Languages. This paper presents a real-world Formosan language speech dataset, including 144 h of news footage for 16 Formosan languages, and uses self-supervised models to obtain and analyze their speech representations. Among the news footage, 13 h of the validated speech data of Formosan languages are selected, and a language classifier, based on XLSR-53, is trained to classify the 16 Formosan languages with an accuracy of 86%. We extracted and analyzed the speech vector representations learned from the model and compared them with 152 manually coded linguistic typological features. The comparison shows that the speech vectors reflect Formosan languages' phonological and morphological aspects. Furthermore, the speech vectors and linguistic features are used to construct a linguistic phylogeny, and the resulting genealogical grouping corresponds with previous literature. These results suggest that we can investigate the current real-world language usages through the speech model, and the dataset opens a window to look into the Formosan languages in vivo.

Despite advancements in pedicle screw design and surgical techniques, the standard steps for inserting pedicle screws still need to follow a set of fixed procedures. The first step, known as establishing a pilot hole, also referred to as a pre-drilled hole, is crucial for ensuring screw insertion accuracy. In different surgical approaches, such as minimally invasive or traditional surgery, the method of creating pilot holes varies, resulting in different pilot hole profiles, including variations in size and shape. The aim of this study is to evaluate the biomechanical properties of different pilot hole profiles corresponding to various surgical approaches. Commercially available synthetic L4 vertebrae with a density of 0.16 g/cc were utilized as substitutes for human bone. Four different pilot hole profiles were created using a 3.0 mm cylindrical bone biopsy needle, 3.6 mm cylindrical drill, 3.2–5.0 mm conical drill, and 3.2–5.0 mm conical curette for simulating various minimally invasive and traditional spinal surgeries. Two frequently employed screw shapes, namely, cylindrical and conical, were selected. Following specimen preparation, screw pullout tests were performed using a material test machine, and statistical analysis was applied to compare the mean maximal pullout strength of each configuration. Conical and cylindrical screws in these four pilot hole configurations showed similar trends, with the mean maximal pullout strength ranking from high to low as follows: 3.0 mm cylindrical biopsy needle, 3.6 mm cylindrical drill bit, 3.2–5.0 mm conical curette, and 3.2–5.0 mm conical drill bit. Conical screws generally exhibited a greater mean maximal pullout strength than cylindrical screws in three of the four different pilot hole configurations. In the groups with conical pilot holes, created with a 3.2–5.0 mm drill bit and 3.2–5.0 mm curette, both conical screws exhibited a greater mean maximal pullout strength than did cylindrical screws. The strength of this study lies in its comprehensive comparison of the impact of various pilot hole profiles commonly used in clinical procedures on screw fixation stability, a topic rarely reported in the literature. Our results demonstrated that pilot holes created for minimally invasive surgery using image-guided techniques exhibit superior pullout strength compared to those utilized in traditional surgery. Therefore, we recommend prioritizing minimally invasive surgery when screw implantation is anticipated to be difficult or there is a specific need for stronger screw fixation. When opting for traditional surgery, image-guided methods may help establish smaller pilot holes and increase screw fixation strength.

Abstract Although an anterior approach with anterior lateral screw fixation has been developed for stabilizing the thoracolumbar spine clinically, screw loosening still occurs. In this novel in vitro study, we attempted to elucidate the optimal screw position in the lateral lumbar vertebra and the effect of bicortical fixation. A total of 72 fresh-frozen lumbar vertebrae from L1–6 were harvested from 12 mature pigs and randomly assigned to two modalities: bicortical fixation (n = 36) and unicortical fixation (n = 36). Six groups of screw positions in the lateral vertebral body in each modality were designated as central-anterior, central-middle, central-posterior, lower-anterior, lower-middle, and lower- posterior; 6 specimens were used in each group. The correlations between screw fixation modalities, screw positions and axial pullout strength were analyzed. An appropriate screw trajectory and insertional depth were confirmed using axial and sagittal X-ray imaging prior to pullout testing. In both bicortical and unicortical fixation modalities, the screw pullout force was significantly higher in the posterior or middle position than in the anterior position (p

The complex process of wound healing depends on the coordinated interaction between various immunological and biological systems, which can be aided by technology. This present review provides a broad overview of the medical applications of piezoelectric and triboelectric nanogenerators, focusing on their role in the development of wound healing technology. Based on the finding that the damaged epithelial layer of the wound generates an endogenous bioelectric field to regulate the wound healing process, development of technological device for providing an exogenous electric field has therefore been paid attention. Authors of this review focus on the design and application of piezoelectric and triboelectric materials to manufacture self-powered nanogenerators, and conclude with an outlook on the current challenges and future potential in meeting medical needs and commercialization.

Ball-and-socket designs of cervical total disc replacement (TDR) have been popular in recent years despite the disadvantages of polyethylene wear, heterotrophic ossification, increased facet contact force, and implant subsidence. In this study, a non-articulating, additively manufactured hybrid TDR with an ultra-high molecular weight polyethylene core and polycarbonate urethane (PCU) fiber jacket, was designed to mimic the motion of normal discs. A finite element (FE) study was conducted to optimize the lattice structure and assess the biomechanical performance of this new generation TDR with an intact disc and a commercial ball-and-socket Baguera®C TDR (Spineart SA, Geneva, Switzerland) on an intact C5-6 cervical spinal model. The lattice structure of the PCU fiber was constructed using the Tesseract or the Cross structures from the IntraLattice model in the Rhino software (McNeel North America, Seattle, WA) to create the hybrid I and hybrid II groups, respectively. The circumferential area of the PCU fiber was divided into three regions (anterior, lateral and posterior), and the cellular structures were adjusted. Optimal cellular distributions and structures were A2L5P2 in the hybrid I and A2L7P3 in the hybrid II groups. All but one of the maximum von Mises stresses were within the yield strength of the PCU material. The range of motions, facet joint stress, C6 vertebral superior endplate stress and path of instantaneous center of rotation of the hybrid I and II groups were closer to those of the intact group than those of the Baguera®C group under 100 N follower load and pure moment of 1.5 Nm in four different planar motions. Restoration of normal cervical spinal kinematics and prevention of implant subsidence could be observed from the FE analysis results. Superior stress distribution in the PCU fiber and core in the hybrid II group revealed that the Cross lattice structure of a PCU fiber jacket could be a choice for a next-generation TDR. This promising outcome suggests the feasibility of implanting an additively manufactured multi-material artificial disc that allows for better physiological motion than the current ball-and-socket design.

Intraoperative pedicle screw depth adjustment after initial insertion, including both forward and backward adjustments, is sometimes necessary to facilitate rod application and ensure that the screw is in the correct position, which is determined by intraoperative fluoroscopy. Adjusting the screw with forward turns has no negative influence on the screw fixation stability; however, screw turnback may weaken the fixation stability. The aim of this study is to evaluate the biomechanical properties of screw turnback and demonstrate the reduction in the fixation stability after the screw is turned 360° from its full insertion position. Commercially available synthetic closed-cell polyurethane foams with three different densities simulating various degrees of bone density were utilized as substitutes for human bone. Two different screw shapes (cylindrical and conical) together with two different pilot hole profiles (cylindrical and conical) were tested. Following specimen preparation, screw pullout tests were conducted using a material test machine. The mean maximal pullout strength between full insertion and 360-degree turnback from full insertion in each setting was statistically analyzed. The mean maximal pullout strength after 360-degree turnback from full insertion was generally lower than that at full insertion. The reduced mean maximal pullout strength after turnback increased with decreasing bone density. Conical screws had significantly lower pullout strength after 360-degree turnback than cylindrical screws. The mean maximal pullout strength was reduced by up to approximately 27% after 360-degree turnback when using a conical screw in a low bone density specimen. Additionally, specimens treated with a conical pilot hole presented a less reduction in pullout strength after screw turnback as compared to those with a cylindrical pilot hole. The strength of our study was that we systematically investigated the effects of various bone densities and screw shapes on screw stability after turnback, which has rarely been reported in the literature. Our study suggests that pedicle screw turnback after full insertion should be reduced in spinal surgeries, particularly procedures that use conical screws in osteoporotic bone. Pedicle screw secured with a conical pilot hole might be beneficial for screw adjustment.

In recent years, micro-sized electric unmanned aerial vehicle (UAVs) have gained widespread applications in both defense and civilian sectors owing to their advantages of lightweight construction, portability, and cost-effectiveness. However, a significant drawback is the difficulty in discerning and controlling the flight attitude and trajectory of these UAVs when operating beyond the line of sight. Consequently, they heavily rely on remote control for flight operations, leading to a high degree of operational complexity. Hence, it is challenging to maintain the desired characteristics of micro-sized aerial vehicle systems, such as high sensitivity and stability. In this study, we aimed to enhance the longitudinal flight stability of micro-sized electric UAVs. To achieve this goal, control of a UAV's elevator was utilized to ensure stability in pitch and roll during flight. We employed the Digital Airborne Tactical Communications System (DATCOM) software developed by the United States Air Force to calculate the fundamental aerodynamic coefficients of the UAV. Subsequently, the longitudinal motion state space equation was employed to derive transfer functions for the pitch angle θ and the horizontal stabilizer deflection de. Furthermore, we utilized Simulink to compare the effects of two control methods, traditional Proportional-Integral-Derivative (PID) and fuzzy PID, on the longitudinal flight stability of the UAV. We aimed to identify the optimal PID values for the UAV. Finally, we validated through practical flight tests that Fuzzy PID can enhance the longitudinal flight stability of the UAV while also contributing to new technological solutions for stability in micro-sized UAV flight. [ABSTRACT FROM AUTHOR]

Microelectronics play a crucial role in medical settings by monitoring physiological signals, treating illnesses, and enhancing human well-being. For implanted and wearable devices, a reliable and continuous energy source is essential. While conventional energy systems rely on batteries and external power connections, their drawbacks, including the need for frequent charging, limited battery lifespan, and the potential for reoperation, restrict their utility. This has spurred the exploration of self-sustaining, long-lasting power solutions. The ultrasound-driven nanogenerator, a promising energy source, harnesses biomechanical energy from activities like muscle movement, heartbeat, respiration, and gastric peristalsis. It converts this energy into electrical signals, enabling the detection of physiological and pathological markers, cardiac pacing, nerve stimulation, tissue repair, and weight management. In this review, we provide an overview of triboelectric (TENG) and piezoelectric (PENG) nanogenerator design with ultrasound and its applications in biomedicine, offering insights for the advancement of self-powered medical devices in the future. These devices hold potential for diverse applications, including wound treatment, nerve stimulation and regeneration, as well as charging batteries in implanted devices.

Abstract Polymethylmethacrylate (PMMA) has been applied clinically and biomechanically repair loose pedicle screws. Controversies have arisen over data due to uncontrolled cement properties, various locations and sizes of fenestrated holes in repair screws, irregular holes and different bone densities of specimens. In this study, the pullout strength was compared for two techniques, the modified technique to use PMMA to augment a threaded hole and the traditional technique with retrograde injection of a PMMA filling, for standard loose screws in porcine vertebrae. Both techniques provided statistically significant results for sufficiently randomized specimens and experimental procedures. The difference in the pullout strength between conical and cylindrical screws for the aforementioned cement augmentation techniques was also investigated. Twenty-four single-level fresh-frozen lumbar vertebrae from L1 to L6 were harvested from four mature pigs. A total of 0.8 ml of PMMA was retrograde injected into screw holes with a 5.5 mm diameter, followed by insertion of a 5.0 mm diameter repair screw in the traditional group (n = 12). A stiff threaded PMMA hole was created with a 4.5 mm tapping screw before insertion of repair screws in the modified group (n = 12). Two screw geometries were randomly assigned as cylindrical (n = 6) and conical (n = 6) in each group. The correlations between filling techniques, screw geometries and axial pullout strength were analyzed. An appropriate screw trajectory and insertion depth were confirmed using X-ray imaging prior to pullout testing in both groups. For a given screw geometry (cylindrical or conical), the pullout force of the modified group was significantly higher than that of the traditional group. There was no significant difference in the pullout force between the screw geometries for a given filling technique. The cement augmentation technique is far more influential than the screw outer geometry. The modified PMMA technique created a greater anchor force than the traditional method and could be an alternative for revision of pedicle screw loosening.

Three key factors are responsible for the biomechanical performance of pedicle screw fixation: screw mechanical characteristics, bone quality and insertion techniques. To the best of the authors’ knowledge, no study has directly compared the biomechanical performance among three trajectories, i.e., the traditional trajectory (TT), modified trajectory (MT) and cortical bone trajectory (CBT), in a porcine model. This study compared the pullout strength and insertion torque of three trajectory methods in single vertebrae, the pullout strength and fixation stiffness including flexion, extension, and lateral bending in a one-level instrumented functional spinal unit (FSU) that mimics the in vivo configuration were clarified. A total of 18 single vertebrae and 18 FSUs were randomly assigned into three screw insertion methods (n = 6 in each trajectory group). In the TT group, the screw converged from its entry point, passed completely inside the pedicle, was parallel to the superior endplate, was located in the superior third of the vertebral body and reached to at least the anterior third of the vertebral body. In the MT group, the convergent angle was similar to that of the TT method but directed caudally to the anterior inferior margin of the vertebral body. The results of insertion torque and pullout strength in single vertebrae were analyzed; in addition, the stiffness and pullout strength in the one-level FSU were also investigated. This study demonstrated that, in single vertebrae, the insertion torque was significantly higher in CBT groups than in TT and MT groups (p < 0.05). The maximal pullout strength was significantly higher in MT groups than in TT and CBT groups (p < 0.05). There was no significant difference in stiffness in the three motions among all groups. The maximal pullout strength in FSUs of MT and CBT groups were significantly higher than the TT groups (p < 0.05). We concluded that either MT or CBT provides better biomechanical performance than TT in single vertebrae or FSUs. The lack of significance of stiffness in FSUs among three methods suggested that MT or CBT could be a reasonable alternative to TT if the traditional trajectory was not feasible.

In this study, carbon-based nanofluids (CBNFs) were prepared using a revised vortex trap method and applied in the direct absorption solar collector (DASC) to evaluate the feasibility of CBNFs in DASC. The thermal storage performance of water and different concentrations of CBNFs (0.01, 0.025 and 0.05 wt%) was assessed with a 1000 W halogen lamp as a simulated light source under different volumetric flow rates (1.5, 3.0, and 4.5 L per minute [LPM]) at a constant thermal storage load (2.4 kg of water) and ambient temperature of 26 °C. The thermal storage capacity, system efficiency factor (SEF), and heating rate of the CBNFs as the working fluid were higher than those of water in most cases. The thermal storage capacity and SEF of 0.05 wt% CBNF at a volumetric flow rate of 3.0 LPM were 10.36% and 9.36% higher than that of water, respectively. The relevant experimental results demonstrate the great potential of CBNFs in DASC.

In this study, we propose a novel design of triangular mesoscale Janus prisms for the generation of the long photonic hook. Numerical simulations based on the finite-difference time-domain method are used to examine the formation mechanism of the photonic hook. The electric intensity distributions near the micro-prisms are calculated for operation at different refractive indices and spaces of the two triangular micro-prisms. The asymmetric vortices of intensity distributions result in a long photonic hook with a large bending angle. The length and the bending angle of the photonic hook are efficiently modulated by changing the space between the two triangular micro-prisms. Moreover, the narrow width of the photonic hook is achieved beyond the diffraction limit. The triangular Janus micro-prisms have high potential for practical applications in optical tweezers, nanoparticle sorting and manipulation and photonic circuits.

Unacceptable sagittal alignment and cement leakage are major concerns of percutaneous vertebroplasty when treating patients with painful vertebral osteoporotic compression fractures. To maintain the restored vertebral height and reduce the reliance on cement as the major stabilizer, an expandable vertebral augment system (EVA®) made of titanium alloy consisting of a rigid tube encased by a barrel with an anterior expansion mechanism was developed. The aim of the current study was to determine whether this novel design is as effective as existing procedures in terms of height restoration and biomechanical performance. Eight osteoporotic vertebrae (T12-L3) confirmed by dual-energy X-ray absorptiometry from two fresh-frozen human cadavers (70- and 72-year-old females) were used. Twenty-five percent reduced anterior wedge vertebral compression fractures were created using a material testing machine. Four randomized specimens were augmented with EVA® (Chang Gu Biotechnology Co. Ltd., Taipei city, Taiwan), and another four randomized specimens were augmented with OsseoFix® (AlphaTec Spine Inc., Carlsbad, CA, USA). The implant size and cement volume were controlled. The anterior vertebral body height (VBH) ratio and pre/postaugmented ultimate strength and stiffness were measured and compared. The mean anterior VBH restoration ratio was 8.54% in the EVA® group and 8.26% in the OsseoFix® groups. A significant difference from augmentation was measured in both groups (p < 0.05), but there was no significant difference between the EVA® and OsseoFix® groups in anterior VBH restoration. The ultimate strengths of the EVA® and OsseoFix® groups were 6071.4 ± 352.6 N and 6262.9 ± 529.2 N, respectively, both of which were statistically significantly higher than that of the intact group (4589.9 ± 474.6 N) (p < 0.05). The stiffnesses of the EVA®, OsseoFix®, and intact groups were 1087.2 ± 176.9, 1154.9 ± 168.9, and 1637.3 ± 340.8 N/mm, respectively, indicating that the stiffness was significantly higher in the intact group than in both the EVA® and OsseoFix® groups (p < 0.05). No significant differences were observed between the two augmentation procedures in height restoration or ultimate strength and stiffness. This novel EVA® system showed comparable height restoration and biomechanical performance to those of existing implants for human cadaveric osteoporotic compression fractures. Potential advantages of preventing cement posterior leakage and promoting cement interdigitation are expected with this ameliorated design.

Histone N-terminal tails and their post-translational modifications affect various biological processes, often in a context-specific manner; the underlying mechanisms are poorly studied. Here, the role of individual N-terminal tails of histones H2A/H2B during transcription through chromatin was analyzed in vitro. spFRET data suggest that the tail of histone H2B (but not of histone H2A) affects nucleosome stability. Accordingly, deletion of the H2B tail (amino acids 1–31, but not 1–26) causes a partial relief of the nucleosomal barrier to transcribing RNA polymerase II (Pol II), likely facilitating uncoiling of DNA from the histone octamer during transcription. Taken together, the data suggest that residues 27–31 of histone H2B stabilize DNA–histone interactions at the DNA region localized ~25 bp in the nucleosome and thus interfere with Pol II progression through the region localized 11–15 bp in the nucleosome. This function of histone H2B requires the presence of the histone H2A N-tail that mediates formation of nucleosome–nucleosome dimers; however, nucleosome dimerization per se plays only a minimal role during transcription. Histone chaperone FACT facilitates transcription through all analyzed nucleosome variants, suggesting that H2A/H2B tails minimally interact with FACT during transcription; therefore, an alternative FACT-interacting domain(s) is likely involved in this process.

Allograft bone particles, hydroxyapatite/β-hydroxyapatite-tricalcium phosphate (HA/β-TCP), calcium sulfate (CS), and polymethylmethacrylate (PMMA) bone cement are biomaterials clinically used to fill defective pedicles for pedicle screw augmentation. Few studies have systematically investigated the effects of various biomaterials utilized for salvage screw stabilization. The aim of this study was to evaluate the biomechanical properties of screws augmented with these four different materials and the effect of different pilot hole sizes and bone densities on screw fixation strength. Commercially available synthetic bones with three different densities (7.5 pcf, 15pcf, 30 pcf) simulating different degrees of bone density were utilized as substitutes for human bone. Two different pilot hole sizes (3.2 mm and 7.0 mm in diameter) were prepared on test blocks to simulate primary and revision pedicle screw fixation, respectively. Following separate specimen preparation with these four different filling biomaterials, a screw pullout test was conducted using a material test machine, and the average maximal screw pullout strength was compared among groups. The average maximal pullout strength of the materials, presented in descending order, was as follows: bone cement, calcium sulfate, HA/β-TCP, allograft bone chips and the control. In samples in both the 3.2 mm pilot-hole and 7.0 mm pilot-hole groups, the average maximal pullout strength of these four materials increased with increasing bone density. The average maximal pullout strength of the bone cement augmented salvage screw (7.0 mm) was apparently elevated in the 7.5 pcf test block. Salvage pedicle screw augmentation with allograft bone chips, HA/β-TCP, calcium sulfate, and bone cement are all feasible methods and can offer better pullout strength than materials in the non-augmentation group. Bone cement provides the most significantly augmented effect in each pilot hole size and bone density setting and could be considered preferentially to achieve larger initial stability during revision surgery, especially for bones with osteoporotic quality.

Background: Postoperative immunosuppression is associated with blood loss and surgical trauma during surgery and subsequently predisposes patients to increased morbidity. Spine endoscopic surgery has been accepted as an effective surgical technique with less surgical trauma and less blood loss for the complication of infectious spondylodiscitis. Therefore, the aim of this study was to investigate whether PEIDF could reduce the morbidity rates for patients with infectious spondylodiscitis. Methods: We launched a retrospective cohort study on the comparison of the perioperative prognosis between PEIDF and conventional open surgery for single-level lumbar infectious spondylodiscitis in patients with poor physical health (ASA ≥ 4) from 2014 to 2019. Results: Forty-four patients were included in this study. Fifteen of them underwent PEIDF, and the rest of the 29 patients were treated with open surgery. Less surgical blood loss (p < 0.001) and intraoperative transfusions (p < 0.001) with a better decline of CRP (p = 0.017) were statistically significant in patients receiving PEIDF. Patients undergoing conventional open surgery encountered more postoperative sepsis (p = 0.030), a higher qSOFA score (p = 0.044), and prolonged-time for CRP normalization (p = 0.001). Conclusions: PEIDF minimizes a poor postoperative outcome due to less surgical trauma, intraoperative blood loss, and the need for a blood transfusion.

Replacement with larger diameter screws is always used in pedicle screw loosening but carries a risk of pedicle wall violation. A pedicle screw with more preserved bone stock is the preferred primary fixation choice. The purpose of this study was to evaluate whether a newly designed proximal-conical dual-thread screw with less bone occupancy provides fixation strength comparable to that of a traditional screw. Six types of pedicle screws based on three different shapes (cylindrical, conical, and proximal-conical) and two thread profiles (single-thread and dual-thread) were grouped. Conical and proximal-conical screws differed mainly in the slope of the outer diameter from the hub to the tip. Conical screws had an outer diameter (6.5 mm) that differed from the hub and tapered by 30% to an outer diameter (4.5 mm) at the tip and proximal-conical screws had the same outer diameter from the hub and tapered by 30% (4.5 mm) at 20 mm from the hub and then maintained the outer diameter (45 mm) to the tip. A total of 36 L4 Sawbones® vertebrae were used in the study and six trials for each screw group. The results of the imaging, screw volume in bone, insertion torque, and pullout force were analyzed. For screws with the same shape, insertion torque and pullout force were significantly higher for those in the dual-thread groups than for those in the single-thread groups (p < 0.05). For screws with the same thread profile, there was no significant difference in either biomechanical test between the different screw shapes (p > 0.05). Our results demonstrated that these proximal-conical dual-thread screws, with the property of relative bone stock preservation, display a comparable biomechanical performance to traditional dual-thread screws and a better performance than single-thread screws. This screw design could serve as the primary pedicle screw choice to reduce revision difficulty.

As the feature size of integrated circuits has been scaled down to 10 nm, the rapid increase in the electrical resistance of copper (Cu) metallization has become a critical issue. To alleviate the resistance increases of Cu lines, co-sputtered CoW and CoB alloying metals were investigated as conductors and barriers in this study. Annealing CoM (M = W or B)/SiO2/p-Si structures reduced the resistivity of CoM alloys, removed sputtering-deposition-induced damage, and promoted adhesion. Additionally, both annealed CoW/SiO2 or CoB/SiO2 structures displayed a negligible Vfb shift from capacitance-voltage measurements under electrical stress, revealing an effective barrier capacity, which is attributed to the formation of MOx layers at the CoM/SiO2 interface. Based on the thermodynamics, the B2O3 layer tends to form more easily than the WOx layer. Hence, the annealed CoB/SiO2/p-Si MIS capacitor had a higher capacitance and a larger breakdown strength did than the annealed CoW/SiO2/p-Si MIS capacitor. [ABSTRACT FROM AUTHOR]

As cultural conflicts are intensifying locally and internationally in the aftermath of COVID-19 pandemic, fine-tuned investigation of culture/religion, especially that of the marginalized populations, holds the potential to reduce disparity and suffering in the global village. This study used 3 textual analysis programs--Topic Modeling, C-LIWC, and SSWC-Chinese--to shed light on the differences in cognition and emotion between two communities with radically different religious beliefs (Bimo and Christianity) among the Yi ethnic minority in Southwest China. Findings from these programs replicated the manual coding results of the previous study, and confirmed the prediction that cultural differences in cognition and emotion between the Yi-Bimo and the Yi-Christian fall along the divide between strong-ties and weak-ties rationality (Sundararajan, 2020a). Demonstrating an edge of advantage over manual coding, this machine-assisted analysis lends convergent validity to the previous study, and presents a more nuanced picture of diversity in emotion and cognition among the Chinese, with practical implications for future research and intervention for the marginalized populations. [ABSTRACT FROM AUTHOR]