Unconventional Spectral Gaps Induced by Charge Density Waves in the Weyl Semimetal (TaSe4)2I.

Coupling Weyl quasiparticles and charge density waves (CDWs) can lead to fascinating band renormalization and many-body effects beyond band folding and Peierls gaps. For the quasi-one-dimensional chiral compound (TaSe4)2I with an incommensurate CDW transition at TC = 263 K, photoemission mappings thus far are intriguing due to suppressed emission near the Fermi level. Models for this unconventional behavior include axion insulator phases, correlation pseudogaps, polaron subbands, bipolaron bound states, etc. Our photoemission measurements show sharp quasiparticle bands crossing the Fermi level at T > TC, but for T < TC, these bands retain their dispersions with no Peierls or axion gaps at the Weyl points. Instead, occupied band edges recede from the Fermi level, opening a spectral gap. Our results confirm localization of quasiparticles (holes created by photoemission) is the key physics, which suppresses spectral weights over an energy window governed by incommensurate modulation and inherent phase defects of CDW.

Influencing factors of examiner: Examples from certificated orthodontists board examination.

BACKGROUND: The rating result reflects not only the performance of the candidate but some extent of the examiner's preference. Examiner bias could be objective, which means it can't be changed by the examiner like gender, age, race, educational level, or professional experience. No study about examiner bias was performed in the dental education realm, especially in the orthodontic field. Therefore, this study aimed to figure out possible influencing factors in examiners from examples of the Taiwan Board of Orthodontist examination. METHODS: The examiner groups comprised 29 males and 21 females selected from the certificated Taiwan Board of Orthodontists. Every examiner would receive a series of lectures about rating standards before the exam. The score data were collected from 2009 to 2019. RESULTS: As for the univariate regression model of the Taiwan Board of Orthodontist examination, the experienced examiner with a certification of more than 15 years tends to rate more leniently, but female examiners tend to rate harsher. The scores would increase with the examiner's age in both the univariate regression model of self-prepared and assigned cases. CONCLUSION: As for the multivariate model of self-prepared exams, the elder and the examiner who work in private practice clinics tend to rate more leniently. As for the multivariate model of the assigned case exam, the score would be only affected by age. However, further studies are necessary to determine the direct relation among these factors.

Dirac Nodal Line in Hourglass Semimetal Nb3SiTe6.

Glide-mirror symmetry in nonsymmorphic crystals can foster the emergence of novel hourglass nodal loop states. Here, we present spectroscopic signatures from angle-resolved photoemission of a predicted topological hourglass semimetal phase in Nb3SiTe6. Linear band crossings are observed at the zone boundary of Nb3SiTe6, which could be the origin of the nontrivial Berry phase and are consistent with a predicted glide quantum spin Hall effect; such linear band crossings connect to form a nodal loop. Furthermore, the saddle-like Fermi surface of Nb3SiTe6 observed in our results helps unveil linear band crossings that could be missed. In situ alkali-metal doping of Nb3SiTe6 also facilitated the observation of other band crossings and parabolic bands at the zone center correlated with accidental nodal loop states. Overall, our results complete the system's band structure, help explain prior Hall measurements, and suggest the existence of a nodal loop at the zone center of Nb3SiTe6.

Antimony oxide nanostructures in the monolayer limit: self-assembly of van der Waals-bonded molecular building blocks.

Antimony oxide nanostructures have been identified as candidates for a range of electronic and optoelectronic applications. Here we demonstrate the growth of 2-dimensional antimony oxide nanostructures on various substrates, including highly oriented pyrolytic graphite (HOPG), MoS2 and α-Bi(110) nanoislands. Using scanning tunneling microscopy (STM) we show that the nanostructures formed are exclusively highly crystalline α-Sb2O3(111) monolayers with a lattice constant of 796 pm ± 7 pm. The nanostructures are triangular with lateral dimensions of up to ∼30 nm. Even though elemental antimony nanostructures are grown simultaneously mixed phases are not observed and both materials exhibit their own distinct growth modes. Moiré patterns are also observed and simulated, allowing confirmation of the atomic unit cell and an understanding of the orientation of the Sb2O3 structures with respect to the supporting materials. As in the bulk, the Sb2O3 nanostructures are formed from Sb4O6 molecules that are weakly interacting through van der Waals forces. This allows physical modification of the nanostructures with the STM tip. Scanning tunnelling spectroscopy reveals a wide band gap of at least 3.5 eV. Finally, we show that possible alternative structures that have unit cells comparable to those observed can be excluded based on our DFT calculations. The considered structures are a 2 × 2 reconstruction of ß-Sb with one vacancy per unit cell and a van der Waals solid composed of Sb4 clusters. Previous reports have predominantly demonstrated Sb2O3 structures with much larger thicknesses.

Association of CTLA-4, TNF alpha and IL 10 polymorphisms with susceptibility to hepatocellular carcinoma.

Our aim was to evaluate the association of genetic polymorphisms of immunoregulatory molecules with susceptibility to hepatocellular carcinoma (HCC). The polymorphisms in CTLA-4 (-318 T/C, CT60 G/A), TNF (-238 G/A, -308 G/A) and IL10 (-592 C/A, -819 C/T) were genotyped by PCR and DNA sequencing. The functional relevance of the polymorphisms was examined by ELISAs, in vitro lymphocyte proliferation assay and cytotoxic assay. The CTLA-4 -318 TC/TT, CTLA-4 CT60 GG, IL10 -592 CA and -819 CT/TT variants, CTLA-4 -318 T and IL 10 -819 T alleles were positively associated with HCC risk (P < .05). While TNF -238 AA variant, TNF -238 A allele were associated with decreased risk of HCC (P < .05). Furthermore, combinations of CTLA-4 -318 TC/TT and TNF -238 GG/GA; CTLA-4 -318 TC/TT and IL 10 -819 CC; CTLA-4 -318 CC and IL 10 -819 CT/TT in patients with HCC were statistically significant (P < .05). Peripheral blood mononuclear cells (PBMCs) carrying -318 TC/TT genotypes exhibited significantly lower proliferation rates, decreased IL-2, IL-4 levels, fewer cytolytic activities and elevated TGF-ß levels. For IL 10 -819 C/T, the CC genotype was significantly associated with higher proliferation rate, decreased TGF-ß, IL-10 levels and higher cytolytic activities (P < .05). For TNF -238 G/A, the AA genotype only had association with serum IL-2, IL-4 (P < .05). In addition, we also found that CTLA-4 -318 T/C, IL-10 -819 T/C variants, combinations of CTLA-4 -318 CC with IL 10 -819 CT or TT, CTLA-4 -318 TC or TT with IL 10 -819 CT or TT were associated with the severity of HCC. These findings suggest that CTLA-4 -318 TC/TT and IL 10 -819 CT/TT could promote the pathogenesis of HCC, which might be related with down-regulation of Th1/Th2-type cytokines and/or up-regulation of Th3-type cytokines.

In Situ Strain Tuning of the Dirac Surface States in Bi2Se3 Films.

Elastic strain has the potential for a controlled manipulation of the band gap and spin-polarized Dirac states of topological materials, which can lead to pseudomagnetic field effects, helical flat bands, and topological phase transitions. However, practical realization of these exotic phenomena is challenging and yet to be achieved. Here we show that the Dirac surface states of the topological insulator Bi2Se3 can be reversibly tuned by an externally applied elastic strain. Performing in situ X-ray diffraction and in situ angle-resolved photoemission spectroscopy measurements during tensile testing of epitaxial Bi2Se3 films bonded onto a flexible substrate, we demonstrate elastic strains of up to 2.1% and quantify the resulting changes in the topological surface state. Our study establishes the functional relationship between the lattice and electronic structures of Bi2Se3 and, more generally, demonstrates a new route toward momentum-resolved mapping of strain-induced band structure changes.

Synovial fluid biomarkers: association with chronic rotator cuff tear severity and pain.

BACKGROUND: We tested the hypothesis that biomarkers in the synovial fluid of the glenohumeral (shoulder) joint are correlated with visual analog scale (VAS) scores, functional scores, and ultrasound findings of chronic rotator cuff tear (RCT) severity. METHODS: We measured biomarkers in shoulder joint synovial fluid of 42 patients with partial-thickness (21), nonmassive full-thickness (10), and massive full-thickness (11) RCTs. Pain duration, tear severity, and VAS and functional scores were compared with interleukin (IL) 1ß, IL-6, matrix metalloproteinase (MMP) 1, and MMP-13 levels. RESULTS: Both MMP-1 and MMP-13 levels were significantly highest in the massive full-thickness group. MMP-13 levels were significantly different between groups, but proinflammatory cytokine IL-1ß and IL-6 levels were not. However, IL-1ß levels were significantly positively correlated with VAS (r = 0.66; P <.01) and functional scores (r = 0.61; P <.01), but IL-6, MMP-1, and MMP-13 levels were not. CONCLUSIONS: IL-1ß levels in shoulder synovial fluid correlated positively with shoulder pain and functional scores in patients with chronic RCTs. Both MMP-1 and MMP-13 levels were altered and increased with cuff tear severity.

Elemental Topological Dirac Semimetal: α-Sn on InSb(111).

Three-dimensional (3D) topological Dirac semimetals (TDSs) are rare but important as a versatile platform for exploring exotic electronic properties and topological phase transitions. A quintessential feature of TDSs is 3D Dirac fermions associated with bulk electronic states near the Fermi level. Using angle-resolved photoemission spectroscopy, we have observed such bulk Dirac cones in epitaxially grown α-Sn films on InSb(111), the first such TDS system realized in an elemental form. First-principles calculations confirm that epitaxial strain is key to the formation of the TDS phase. A phase diagram is established that connects the 3D TDS phase through a singular point of a zero-gap semimetal phase to a topological insulator phase. The nature of the Dirac cone crosses over from 3D to 2D as the film thickness is reduced.

Dirac Fermions in Borophene.

Honeycomb structures of group IV elements can host massless Dirac fermions with nontrivial Berry phases. Their potential for electronic applications has attracted great interest and spurred a broad search for new Dirac materials especially in monolayer structures. We present a detailed investigation of the ß_{12} sheet, which is a borophene structure that can form spontaneously on a Ag(111) surface. Our tight-binding analysis revealed that the lattice of the ß_{12} sheet could be decomposed into two triangular sublattices in a way similar to that for a honeycomb lattice, thereby hosting Dirac cones. Furthermore, each Dirac cone could be split by introducing periodic perturbations representing overlayer-substrate interactions. These unusual electronic structures were confirmed by angle-resolved photoemission spectroscopy and validated by first-principles calculations. Our results suggest monolayer boron as a new platform for realizing novel high-speed low-dissipation devices.

[Research on the Noise Reduction with Hyper-Resolution Infrared Spectrum Based on Improved PCV Method].

The noise reduction with observed high resolution infrared radiance is crucial to improve the accuracy and stability of the retrieval of thermodynamic profiles. When applying the principal component analysis noise filter algorithm to the observed radiance, the optimal number k of principal components that used in the algorithm was mostly calculated with the statistical and empirical method. The percent cumulative variance method is one of the statistical methods that have been commonly used to calculate k, however, the threshold of the percent cumulative variance was determined subjectively and arbitrarily, which limits the application of this method. While the empirical method need the real-time Noise-Equivalent Spectral Radiance (NESR) to normalize non uniform noise in the observed data, but the real-time NESR needs the raw data of complex spectrum which is not easy to obtain in most cases. Aiming at the solving the problems above, a PCA noise filter based on the Improved PCV algorithm is proposed, of which the threshold is determined by iteratively calculating the difference between the simulated and reconstructed spectrum using different principal components, whereby k is determined such that the PCV is larger than the threshold. The new method solves the problem of arbitrary of the determination of k, and at the same time it doesn't need the real-time NESR to normalize the observed radiance. First, the impact of normalization on the noise reduction is analyzed using physical retrieval of temperature profiles; the result shows that the impact is very small, which less than the impact of calculation error of k is caused by normalization on the retrieval of temperature profiles. Then, the noise reduction of the representative radiance data which covers four quarters of 2011 shows that, the RMSE of the retrieved temperature profile using the Improved PCV method is improved by 0.1 K compared to the factor indicator function method when the real-time NESR is not available, and it is almost the same with the latter when the normalization is done. Under the condition that the NESR is not available, the method proposed in this article could objectively and reasonably reduce the noise level of the ground-based high resolution infrared radiance.

[Research on Cloud Phase Detemination Using Infrared Emissivity Spectrum Data (2): Retrieval of Cloud Effective Radius and Water Path].

The cloud microphysical properties such as cloud effective radius and cloud water path are fundamental properties for understanding the cloud formation, radiative impacts and interactions with aerosol and precipitation. The downwelling infrared radiance spectra is studied here to retrieve microphysical properties of clouds. The sensitivity of the downwelling radiance spectra and cloud emissivity spectra to the liquid cloud and ice cloud effective radius and optical depth is analyzed. The look-up-tables are established for optically thin clouds (cloud optical depth less than 6) that rely on parameters of the slopes and differences of the emissivity spectra. These parameters include the difference in the emissivity between 862.1 and 934.9 cm(-1), the difference in the emissivity between 1 900.1 and 2 170.1 cm(-1), the slope of the cloud emissivity and the radiation between 900 and 1 000 cm(-1), the slope of the cloud emissivity and the radiation between 1 100 and 1 200 cm(-1). The look-up-tables are constrained by the incorporation of mean ozone band transmissivity between 1 050 and 1 060 cm(-1). Cloud effective radius and optical depth can be obtained with by least squares fitting between observed and modeled above-mentioned multiple spectral parameters. The cloud water path can then be derived from the experiential relationship. The inversion results are compared with the ARM baseline cloud microphysics product (MICROBASE). It is shown that, the cloud effective radius is roughly in the same order of magnitude while the water paths derived from both method are of large differences especially for the liquid cloud path. The algorithm proposed in this paper is efficient for retrieving microphysical properties of thin clouds with cloud optical depth less than 6.

[Research on Cloud Phase Detemination Using Infrared Emissivity Spectrum Data (1): Cloud Phase Determination].

As a key factor in the climate model, cloud phase is an important prerequisite to performing cloud property retrievals from remote sensor measurements. The ability to infer cloud phase using cloud emissivity spectra is investigated by numerical simulations. It is shown that for emissivity below 0.95, several spectral features such as the slopes, the ratios and the differences of the emissivity are consistent with the variation of cloud phase in some spectral regions. Specifically, these features include the slope of the cloud emissivity between 800 and 900 cm(-1), the slope of the cloud emissivity between 900 and 1 000 cm(-1), the difference in the mean emissivity between above-mentioned two regions, the ratio of the emissivity at 862.1 cm(-1) to the emissivity at 989.8 cm(-1), the difference in the emissivity between 862.1 and 989.8 cm(-1), the ratio of the emissivity at 1 900.1 cm-1 to the emissivity at 2 029.3 cm-1, the ratio of the mean emissivity for far-infrared region to the emissivity at 900 cm(-1). A cloud phase classifier is proposed based on support vector machines (SVM). A series of simulations including various cloud patterns are performed. The RBF kernel function parameters and the penalty factor of SVM are selected by using the genetic algorithm. The phase determination algorithm is applied for collecting data from the AERI at the SGP site. The results from the ground-based multisensor cloud phase classifier proposed by Shupe are used to validate the phase determination algorithm. It is found the two results are consistent in general. 30% clouds are indicated as opaque due to its high emissivity. The cloud with small lidar's depolarization is misclassified as clear sky by the Shupe method. It can be concluded that the proposed algorithm considering the spectral information (spectral slopes, ratios and differences) is efficient for cloud phase determination of thin cloud.

[The Application of the L-Curve Method in the Retrieval of Temperature Profiles Using Ground-Based Hyper-Spectral Infrared Radiance].

The thermodynamic profiles of Planetary Boundary Layer could be retrieved by using ground-based hyper-spectral infrared radiance. The AERIoe algorithm has a better performance at the dependency of initial profiles than the "onion peeling" method which was originally applied in the Atmospheric Emitted Radiance Interferometer. The regularization parameter is the key to the AERIoe algorithm, and the strategy for choosing the regularization parameter in the retrieval algorithm is based on the empirical method, which requires too much time for computation while the empirical method needs many iteration steps. A L-curve criterion is proposed to calculate the regularization parameter in AERIoe algorithm. The L-curve criterion is based on a log-log plot of corresponding values of the residual and solution norms, and the optimal regularization parameter corresponds to a point on the curve near the "corner" of the L-shaped region. Therefore, the L-curve criterion has better theoretical basis than the traditional empirical method. The result of retrieval experiment using the observed data collected at the SGP site of the year 2011 shows that, the L-curve method has a good performance in terms of stability, convergence and accuracy of the retrieval. Compared with empirical method, L-curve algorithm converges more quickly which saves much computation time when retrieving the temperature profiles. When considering the retrieval accuracy, the L-curve method has a better behavior at the middle and top of the boundary layer, with an improvement of 0.2 K of RMSE at the altitude of 1～3 km than the empirical method. Therefore, the L-curve algorithm has a better performance compared with the empirical method when choosing the regularization parameter in the retrieval of temperature profiles using the ground-based hyper-spectral infrared radiance.

Ultrasonographically Guided Percutaneous Carpal Tunnel Release: Early Clinical Experiences and Outcomes.

PURPOSE: To present the technique and results of ultrasonographically guided percutaneous carpal tunnel release (PCTR) in a consecutive series of patients with carpal tunnel syndrome (CTS). METHODS: We used previously defined landmarks with the "safe zones," localization, estimated size, and extent of the transverse carpal ligament (TCL) for this prospective clinical study of 91 consecutive cases of carpal tunnel release treated with this technique. The follow-up consisted of 4 time points (1 week and 2, 6, and 12 months) and a final evaluation at an average of 22.5 months. RESULTS: The sensory disturbances disappeared in 76.8%, 93.4%, 100%, and 100% of the patients at 1 week and 2, 6, and 12 months postoperatively, respectively. Moderate pain was experienced in 24.2% of patients within 1 week, in 6.6% of patients within 2 months, and in 1.1% of patients within 12 months after the operation. In the final evaluation, 2 hands were graded as unsatisfactory: one hand had moderate wrist pain without sensory disturbance, and one hand had a recurrence 14 months after the operation. There were no intraoperative or postoperative complications. CONCLUSIONS: Ultrasonographically assisted PCTR is a safe and effective procedure, but it is technically demanding and requires substantial training to be proficient in its use. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Phonons of the anomalous element cerium.

Many physical and chemical properties of the light rare-earths and actinides are governed by the active role of f electrons, and despite intensive efforts the details of the mechanisms of phase stability and transformation are not fully understood. A prominent example which has attracted a lot of interest, both experimentally and theoretically over the years is the isostructural γ - α transition in cerium. We have determined by inelastic X-ray scattering, the complete phonon dispersion scheme of elemental cerium across the γ → α transition, and compared it with theoretical results using ab initio lattice dynamics. Several phonon branches show strong changes in the dispersion shape, indicating large modifications in the interactions between phonons and conduction electrons. This is reflected as well by the lattice Grüneisen parameters, particularly around the X point. We derive a vibrational entropy change ΔS(γ-α)(vib) ≈ (0.33+/-0.03)k(B), illustrating the importance of the lattice contribution to the transition. Additionally, we compare first principles calculations with the experiments to shed light on the mechanism underlying the isostructural volume collapse in cerium under pressure.

Topological Quantum Well States in Pb/Sb Thin-Film Heterostructures.

Composite topological heterostructures, wherein topologically protected states are electronically tuned due to their proximity to other matter, are key avenues for exploring emergent physical phenomena. Particularly, pairing a topological material with a superconductor such as Pb is a promising means for generating a topological superconducting phase with exotic Majorana quasiparticles, but oft-neglected is the emergence of bulklike spin-polarized states that are quite relevant to applications. Using high-resolution photoemission spectroscopy and first-principles calculations, we report the emergence of bulk-like spin-polarized topological quantum well states with long coherence lengths in Pb films grown on the topological semimetal Sb. The results establish Pb/Sb heterostructures as topological superconductor candidates and advance the current understanding of topological coupling effects required for realizing emergent physics and for designing advanced spintronic device architectures.

The use of ultrasound for monitoring reduction and ulnar nerve subluxation in pediatric humeral supracondylar fractures.

BACKGROUND: Traditional treatment for displaced humeral supracondylar fractures (SCFs) in children involves closed reduction (CR) under fluoroscopic guidance, percutaneous pinning, and immobilization with a long-arm cast. This study aims to explore the viability of using radiation-free ultrasound (US) for guiding CR and tracking ulnar nerve dynamics during medial pinning, contrasting the US method with the conventional cross pinning technique. MATERIALS AND METHODS: We assessed 70 children with acute displaced SCFs. The US group (n = 30) underwent US-guided reduction, whereas the traditional group (n = 40) underwent fluoroscopy-guided reduction. Both groups received percutaneous cross pinning and subsequent cast immobilization. Postoperative outcomes were compared between the two methods after a 6-month follow-up. In the US group, ultrasonography assessed fracture displacement distances before and after CR. The angle at which the ulnar nerve relocated to the cubital tunnel during elbow extension was documented using real-time US monitoring during medial pinning. RESULTS: The US group demonstrated improved reduction accuracy, increased range of motion, superior restoration of both Baumann and Humeroulnar angles, and a decreased incidence of malunions compared to the traditional group (all p < 0.05). The ultrasonographic measurement of fracture displacement was comparable with that of fluoroscopy (intraclass correlation coefficient > 0.90). In the US group, no ulnar nerve injury was noted, compared to 2.5 % in the traditional group, and real-time US observations revealed ulnar nerve hypermobility, with 53.3 % of patients exhibiting anterior ulnar nerve subluxation at 120° elbow flexion, 40 % at 90°, 16.7 % at 60°, and none at 30° flexion. CONCLUSION: Ultrasound is as reliable as fluoroscopy for evaluating fracture reductions. The use of intra-operative ultrasound significantly improves reduction accuracy and radiographic outcomes while reducing the risk of ulnar nerve injury.

Uniform Diffusion of Cooper Pairing Mediated by Hole Carriers in Topological Sb2Te3/Nb.

Spin-helical Dirac Fermions at a doped topological insulator's boundaries can support Majorana quasiparticles when coupled with s-wave superconductors, but in n-doped systems, the requisite induced Cooper pairing in topological states is often buried at heterointerfaces or complicated by degenerate coupling with bulk conduction carriers. Rarely probed are p-doped topological structures with nondegenerate Dirac and bulk valence bands at the Fermi level, which may foster long-range superconductivity without sacrificing Majorana physics. Using ultrahigh-resolution photoemission, we report proximity pairing with a large decay length in p-doped topological Sb2Te3 on superconducting Nb. Despite no momentum-space degeneracy, the topological and bulk states of Sb2Te3/Nb exhibit the same isotropic superconducting gaps at low temperatures. Our results unify principles for realizing accessible pairing in Dirac Fermions relevant to topological superconductivity.

Realization of a two-dimensional Weyl semimetal and topological Fermi strings.

A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.

Sonographically assisted percutaneous removal of screws in dynamization of the interlocking intramedullary nail.

OBJECTIVES: Dynamization is a method of removing the interlocking screw(s) farthest from the fracture site for improving healing in femoral and tibial fractures that show delayed healing after static interlocking nailing. We describe a simple sonographically assisted technique for percutaneous dynamization of deep-seated impalpable screws. METHODS: Between March 2001 and March 2005, 20 dynamization procedures were completed using the developed technique under the diagnosis of delayed healing or a nonunion at a mean of 4.8 months after index surgery. After adequately positioning the involved leg, the transducer was placed on the area of the inlet of the screw. Longitudinal and transverse sonographically scanned sections, used to show the head of the screw, were then marked on the skin where the two sections intersected. After this precise marking, a small incision on the mark allowed insertion of the screwdriver and easy percutaneous removal of the screw using only local anesthesia for pain control. RESULTS: We removed 31 screws: 9 proximal femoral screws, 20 distal femoral screws, and 2 proximal tibial screws. The mean depth of the screws was 3.4 cm. The mean operation times were 1.6 minutes for the sonographic examination and 3.5 minutes for removal of one screw. No infections or morbidities were caused by the procedure. CONCLUSIONS: Sonography is an effective tool for localizing a locked screw and facilitates percutaneous removal of screws under only local anesthesia for dynamization. This method needs no special instruments and reduces the time needed for dissecting the tissue and locating the screw.