Coplanar Alignment Research Articles

Risk Factors for Postoperative Shoulder Imbalance in Patients with Lenke Type 1 and 2 Scoliosis Treated using the Vertebral Coplanar Alignment Technique.

This was a multicenter retrospective cohort study. We investigated the incidence of postoperative shoulder imbalance (PSI) and its risk factors in patients with Lenke types 1 and 2 scoliosis corrected using vertebral coplanar alignment (VCA). PSI in scoliosis affects patient quality of life. While other correction methods have reported a high correction rate for the main thoracic curve (MTC) in relation to PSI, this correlation has not been confirmed for the VCA technique. We studied 176 patients with Lenke types 1 and 2 scoliosis who underwent posterior corrective fusion surgery using the VCA technique at 11 institutions. At two years postoperatively, patients were divided into two groups based on radiographic shoulder height (RSH): PSI- (RSH<2cm) and PSI+ (RSH≧2cm) groups. We analyzed the risk factors for PSI. The overall incidence of PSI two years postoperatively was 11.4% (20/176), with 9.2% (11/119) and 15.8% (9/57) in patients with Lenke types 1 and 2, respectively. Contrary to a previous study, a high MTC correction rate did not emerge as a risk factor for PSI. Instead, preoperative left shoulder elevation and low postoperative thoracic kyphosis and greater T1 tilt and high apical vertebral body-to-rib ratio were associated with PSI in patients with Lenke type 1. Preoperative left shoulder elevation and a low postoperative proximal thoracic curve (PTC) correction rate were identified as risk factors for PSI in patients with Lenke type 2. Our results suggest that proper correction of the PTC, rather than compromise MTC correction, may help prevent PSI in the VCA technique. This method is particularly advantageous for addressing Lenke type 1 scoliosis and yields favorable outcomes in shoulder balance. Patients with preoperative left shoulder elevation, especially Lenke type 2, are at high risk of developing PSI. 4.

Unleashing the potential of π-conjugated [B2O3(OH)2] to enhance birefringence in DUV crystals

It is still an urgent problem to develop new DUV birefringent functional units and investigate the enhancement mechanism of birefringence to explore new DUV birefringent materials with outstanding comprehensive performance. In principle, increasing the polarizability anisotropy of the functional groups and maintaining a coplanar alignment are the key factors to achieve a large birefringence. Herein, by replacing [PO4] with [HPO3], the first borophosphite LiB3O3(OH)2(HPO3) was successfully designed based on optimizing the tetrahedra strategy. Meanwhile, by the cation-tuned modification strategy to manipulate the anionic group arrangement, K2NaB6P2O13(OH)5·2H2O was also successfully synthesized. Owing to the coplanar arrangement of π-conjugated groups, both of them exhibit large birefringence (0.09 and 0.08 @532 nm). Furthermore, reported compounds feature large bandgap (Eg = 7.81 and 7.27 eV) which further indicates that they are potential DUV birefringent crystals, and it also demonstrates the feasibility of the above strategies.

Relativistic Effects on Circumbinary Disk Evolution: Breaking the Polar Alignment around Eccentric Black Hole Binary Systems

We study the effects of general relativity (GR) on the evolution and alignment of circumbinary disks around binaries on all scales. We implement relativistic apsidal precession of the binary into the hydrodynamics code phantom. We find that the effects of GR can suppress the stable polar alignment of a circumbinary disk, depending on how the relativistic binary apsidal precession timescale compares to the disk nodal precession timescale. Studies of circumbinary disk evolution typically ignore the effects of GR, which is an appropriate simplification for low-mass or widely separated binary systems. In this case, polar alignment occurs, provided that the disks initial misalignment is sufficiently large. However, systems with a very short relativistic precession timescale cannot polar align and instead move toward coplanar alignment. In the intermediate regime where the timescales are similar, the outcome depends upon the properties of the disk. Polar alignment is more likely in the wavelike disk regime (where the disk viscosity parameter is less than the aspect ratio, α < H/r), since the disk is in good radial communication. In the viscous disk regime, disk breaking is more likely. Multiple rings can destructively interact with one another, resulting in short disk lifetimes and the disk moving toward coplanar alignment. Around main-sequence star or stellar mass black hole binaries, polar alignment may be suppressed far from the binary, but in general, the inner parts of the disk can align to polar. Polar alignment may be completely suppressed for disks around supermassive black holes for close binary separations.

Coplanar embedding of multiple 3D cell models in hydrogel towards high-throughput micro-histology

Standardised and high-throughput methods have been developed for the production and experimental handling of some 3D in vitro models. However, adapted analytical tools are still missing for scientists and researchers to fully exploit the potential of complex cellular models in pre-clinical drug testing and precision medicine. Histology is the established, cost-effective and gold standard method for structural and functional tissue analysis. However, standard histological processes are challenging and costly to apply to 3D cell models, as their small size often leads to poor alignment of samples, which lowers analysis throughput. This body of work proposes a new approach: HistoBrick facilitates histological processing of spheroids and organoids by enabling gel embedding of 3D cell models with precise coplanar alignment, parallel to the sectioning plane, thus minimising the loss of sample material. HistoBrick’s features are compatible with automation standards, potentially allowing automated sample transfer from a multi-well plate to the gel device. Moreover, HistoBrick’s technology was validated by demonstrating the alignment of HepG2 cultured spheroids measuring 150–200 µm in diameter with a height precision of ± 80 µm. HistoBrick allows up to 96 samples to be studied across minimal sections, paving the way towards high-throughput micro-histology.

Formation of Polar Terrestrial Circumbinary Planets

Abstract All circumbinary planets (CBPs) currently detected are in orbits that are almost coplanar to the binary orbit. While misaligned CBPs are more difficult to detect, observations of polar-aligned circumbinary gas and debris disks around eccentric binaries suggest that polar planet formation may be possible. A polar-aligned planet has a stable orbit that is inclined by 90° to the orbital plane of the binary with an angular momentum vector that is aligned to the binary eccentricity vector. With n-body simulations we model polar terrestrial planet formation using hydrodynamic gas disk simulations to motivate the initial particle distribution. Terrestrial planet formation around an eccentric binary is more likely in a polar alignment than in a coplanar alignment. Similar planetary systems form in a polar alignment around an eccentric binary and a coplanar alignment around a circular binary. The polar planetary systems are stable even with the effects of general relativity. Planetary orbits around an eccentric binary exhibit tilt and eccentricity oscillations at all inclinations; however, the oscillations are larger in the coplanar case than the polar case. We suggest that polar-aligned terrestrial planets will be found in the future.

Vertebral Coplanar Alignment Technique Versus Bilateral Apical Vertebral Derotation Technique in Neuromuscular Scoliosis.

Single-center retrospective analysis of prospectively collected data. Our aim was to compare the correction capacity in 3 planes of the VCA technique versus the AD technique in neuromuscular scoliosis patients. We analized patients with neuromuscular scoliosis that underwent posterior spinal fusion from 2013 to 2017 using 2 different techniques for correction: vertebral coplanar alignment (VCA) that takes into consideration the fact that the medial cortex is more resistant than the lateral cortex, with more anchor points for better distribution of forces and ligamentotaxis and the more widely spread apical derotation (AD) technique. Clinical, surgical, and radiographic information of patients operated on with the AD technique were compared to those operated on with the VCA technique in the coronal, sagittal and axial plane at pre-op, immediate post-op, and 2 year follow-up. 64 patients met inclusion criteria, 34 patients underwent the VCA technique and 30 patients underwent the AD technique. The 2 cohorts did not differ in terms of demographics, clinical presentation or preoperative alignment. There were no significant differences in the correction ability between both techniques regarding curve magnitude, apical vertebral rotation, or pelvic obliquity. There was a significant decrease in thoracic kyphosis in the AD group compared to the VCA group in the immediate postop period (4.2 ± 26.6º for VCA and 13.2 ± 21.3º for AD (p = 0.048)). Both apical derotation technique and vertebral coplanar alignment allow for correction in the 3 planes for patients with neuromuscular scoliosis. VCA is a less hypokyphosing technique than AD.

Vertebral coplanar alignment for patients with AIS Lenke type 3 and 4, case series

Vertebral coplanar alignment for patients with AIS Lenke type 3 and 4, case series

Satisfactory restoration of thoracic kyphosis in Lenke I AIS curves using bilateral vertebral coplanar alignment: an international multicenter experience.

Review of a prospective multicenter registry. To report the correction of the thoracic sagittal profile in Lenke 1 curves using the bilateral vertebral coplanar alignment (BVCA) maneuver. All-pedicle-screw construtcs provide satisfactory coronal correction but fail to accurately restore the frequent thoracic hypokyphosis of Lenke 1 curves. BVCA is a recently described technique focused on restoration of the normal thoracic kyphosis alignment in AIS patients. A non-consecutive series of 49 AIS patients underwent surgical correction of the deformity by only posterior pedicle screw construct. Coronal and sagittal curve correction was assessed by conventional standing X-rays at preoperative and 2-year follow-up visits. BVCA reduction maneuvers include the correction of the deformity, while descending an implantable rod within slotted tubes attached to the convex side screws. Restoration of physiologic kyphosis is achieved by spreading the distal ends of the tubes at the thoracic spine using different-sized spacers. Mean preoperative Cobb of the MT curves was 58.4° and was corrected at 70.9%. Preoperative apical vertebral rotation was 18.6° on average and was corrected at 52.9%. T5-T12 kyphosis showed a significant improvement from a mean angle of 18.8º (95% CI 13.3-24.8) to 23.5º (95% CI 20.1-26.1) at 2-year follow-up (a 25% increase) (p = 0.040). Patients with (-) sagittal modifier gained 13.9º on average; those with ( +) modifier decreased 24.0°, and patients with N sagittal modifier remained almost unchanged (2.9°). Differences in the changes of the thoracic sagittal profile between the three groups were statistically significant (p < 0.001). After surgical correction of scoliosis, 87.8% of the patients were considered normokyphotic. Clinical results have proven the ability of BVCA to obtain good correction of the deformity in the coronal plane, similar to other methods. However, this technique permits a more relevant restoration of thoracic kyphosis.

Compact Shape Morphing Tensegrity Robots Capable of Locomotion.

Robustness, compactness, and portability of tensegrity robots make them suitable candidates for locomotion on unknown terrains. Despite these advantages, challenges remain relating to ease of fabrication, shape morphing (packing-unpacking), and locomotion capabilities. The paper introduces a design methodology for fabricating tensegrity robots of varying morphologies with modular components. The design methodology utilizes perforated links, coplanar (2D) alignment of components and individual cable tensioning to achieve a 3D tensegrity structure. These techniques are utilized to fabricate prism (three-link) tensegrity structures, followed by tensegrity robots in icosahedron (six-link), and shpericon (curved two-link) formation. The methodology is used to explore different robot morphologies that attempt to minimize structural complexity (number of elements) while facilitating smooth locomotion (impact between robot and surface). Locomotion strategies for such robots involve altering the position of center-of-mass (referred to as internal mass shifting) to induce “tip-over.” As an example, a sphericon formation comprising of two orthogonally placed circular arcs with conincident center illustrates smooth locomotion along a line (one degree of freedom). The design of curved links of tensegrity mechanisms facilitates continuous change of the point of contact (along the curve) that results from the tip-over. This contrasts to the sudden and piece-wise continuous change for the case of robots with traditional straight links which generate impulse reaction forces during locomotion. The two resulting robots—the Icosahedron and the Sphericon Tensegrity Robots—display shape morphing (packing-unpacking) capabilities and achieve locomotion through internal mass-shifting. The presented static equilibrium analysis of sphericon with mass is the first step in the direction of dynamic locomotion control of these curved link robots.

Structural Basis for the Specific Cotranslational Incorporation of p-Boronophenylalanine into Biosynthetic Proteins.

The site-specific incorporation of the non-natural amino acid p-boronophenylalanine (Bpa) into recombinant proteins enables the development of novel carbohydrate-binding functions as well as bioorthogonal chemical modification. To this end, Bpa is genetically encoded by an amber stop codon and cotranslationally inserted into the recombinant polypeptide chain at the ribosome by means of an artificial aminoacyl-tRNA synthetase (aaRS) in combination with a compatible suppressor tRNA. We describe the crystal structure of an aaRS specific for Bpa, which had been engineered on the basis of the TyrRS from Methanocaldococcus jannaschii, in complex with both Bpa and AMP. The substrates are bound in an orientation resembling the aminoacyl-AMP mixed anhydride intermediate and engaged in a network of four hydrogen bonds that allows specific recognition of the boronate moiety by the aaRS. The key determinant of this interaction is the coplanar alignment of its Glu162 carboxylate group with Bpa, which results in a double hydrogen bond with the boronic acid substituent. Our structural study elucidates how a small set of five side chain exchanges within the TyrRS active site can switch its substrate specificity to the hydrophilic amino acid Bpa, thus stimulating the reprogramming of other aaRS to recruit useful non-natural amino acids for next-generation protein engineering.

Highly Conductive Optical Quality Solution‐Processed Films of 2D Titanium Carbide

MXenes comprise a new class of solution‐dispersable, 2D nanomaterials formed from transition metal carbides and nitrides such as Ti3C2. Here, it is shown that 2D Ti3C2 can be assembled from aqueous solutions into optical quality, nanometer thin films that, at 6500 S cm−1, surpass the conductivity of other solution‐processed 2D materials, while simultaneously transmitting &gt;97% of visible light per‐nanometer thickness. It is shown that this high conductivity is due to a metal‐like free‐electron density as well as a high degree of coplanar alignment of individual nanosheets achieved through spincasting. Consequently, the spincast films exhibit conductivity over a macroscopic scale that is comparable to the intrinsic conductivity of the constituent 2D sheets. Additionally, optical characterization over the ultraviolet‐to‐near‐infrared range reveals the onset of free‐electron plasma oscillations above 1130 nm. Ti3C2 is therefore a potential building block for plasmonic applications at near‐infrared wavelengths and constitutes the first example of a new class of solution‐processed, carbide‐based 2D optoelectronic materials.

Hydrothermal synthesis and characterization of the lutetium borate–nitrate Lu2B2O5(NO3)2·2H2O

The lutetium diborate–dinitrate Lu2B2O5(NO3)2·2H2O was discovered through a hydrothermal synthesis from Lu(NO3)3·H2O and H3BO3. The compound crystallizes in the space group P1̅ (no. 2) with the lattice parameters a=789.52(5), b=988.62(6), c=1460.33(8) pm, α=90.83(1), β=101.75(1), and γ=110.02(1)° (Z=4). Isolated [B2O5]4− units show coplanar alignment and the coordinating [NO3]− groups are stacked perpendicular to the borate plane. Thereby, a novel, open arrangement solely built up from diborate and nitrate groups at a 1:1 ratio is formed. Additionally, Lu2B2O5(NO3)2·2H2O is characterized by vibrational spectroscopy (IR/Raman).

Vertebral coplanar alignment technique: a surgical option for correction of adult thoracic idiopathic scoliosis.

Previous studies have demonstrated vertebral coplanar alignment (VCA) as an effective surgical option for adolescent idiopathic scoliosis (AIS). The purpose of this study is to analyze the outcome of VCA for the surgical correction of adult idiopathic scoliosis (AdIS). 35 AdIS patients (mean age: 24.2 years) undergoing VCA-instrumentation were reviewed. The main thoracic curve and thoracic kyphosis (TK, T5-T12) were evaluated preoperatively, immediate postoperatively, and at the final follow-up (>1 year). All patients were stratified by the TK modifier before surgery: "+" (TK, >40°), "-" (TK, <10°), and "N" (TK, 10°-40°) for normal. The apical vertebral body-to-rib ratio (AVB-R), rib hump (RH), and rotational angle to sacrum (RAsac) were measured to assess the correction of rotational deformity. Quality of life was evaluated with SRS-20 questionnaires. The main thoracic curve (59.1° vs. 19.3°, P < 0.001) and rotational deformity (AVB-R: 2.4 vs. 1.7 %, P < 0.001, RH: 34.9 vs. 19.1 mm, P < 0.001, RAsac: 19.6° vs. 11.9°, P < 0.001) were significantly reduced with surgery. Sagittal deformity improved significantly in group "+" (51.4° vs. 31.6°, P < 0.001) and group "-" (6.2° vs. 20.1°, P < 0.001), while no significant postoperative change in TK was observed in group "N" (23.5° vs. 26.3°, P = 0.270). Patients were followed for an average of 18.7 months with no significant loss of correction. SRS scores improved greatly from 57.7 preoperatively to 71.6 at the final follow-up. VCA can be effectively used for the correction of the coronal and rotational deformity, with better sagittal profile restoration in adult thoracic idiopathic scoliosis with sagittal malalignment.

Direct Vertebral Rotation versus Derotation Technique in Lenke Type 1 Idiopathic Scoliosis

Introduction To date, most of scoliosis corrections are made by derotation and translation of the road from the concave side. The coplanar alignment (VCA) technique recovers the normal anatomy of the spine in its three dimensions, correcting rotation, translation, and restoring the surgical outcomes of VCA against derotation maneuver in selective fusions of patients with Lenke 1 idiopathic scoliosis. Patients and Methods Prospective trial of 21 patients with Lenke 1 idiopathic scoliosis. Fusion levels were determined according to Lenke criteria. In group A (10 patients), the VCA was used; and in group B (11 patients), we perform derotation maneuvers. Multiple radiographic variables were analyzed and SRS-22 was also measured. Results Both the groups were similar in terms of preoperative demographic and radiological variables. Coronal Cobb correction rate was 66.5% in group A and 70.06% in group B. There were no differences in postoperative thoracic kyphosis (group A: 29degrees/group B: 30 degrees, p = 0.9438), but we found a significant difference in the correction of apical translation (group A: 14.5 mm vs. group B: 17 mm, p = 0.0069). None of the groups presented vascular or neurological complications. The SRS-22 score improved significantly after 1-year follow-up without differences between the groups. Conclusion In treating Lenke 1 idiopathic scoliosis with selective fusion, both techniques provide good clinical and radiological results. The only advantage of VCA lies in allowing a better correction of apical translation.

A large deflection and high payload flexure-based parallel manipulator for UV nanoimprint lithography: Part II. Stiffness modeling and performance evaluation

This paper presents a flexure-based parallel manipulator (FPM) that delivers nanometric co-planar alignment and direct-force imprinting capabilities to automate an ultra-violet nanoimprint lithography (UV-NIL) process. The FPM is articulated from a 3-legged Prismatic-Prismatic-Spherical (3PPS) parallel-kinematic configuration to deliver a θx–θy–Z motion. The developed FPM achieves a positioning and orientation resolution of ±10nm and 0.05″, respectively, and a continuous output force of 150N/A throughout a large workspace of 5°×5°×5mm. Part I mainly focuses on a new theoretical model that is used to analyze the stiffness characteristics of the compliant joint modules that formed the FPM, and experimental evaluations of each compliant joint module. Part II presents the stiffness modeling of the FPM, the performance evaluations of the developed prototype, and the preliminary results of the UV-NIL process.

A large deflection and high payload flexure-based parallel manipulator for UV nanoimprint lithography: Part I. Modeling and analyses

This paper presents a flexure-based parallel manipulator (FPM) that delivers nanometric co-planar alignment and direct-force imprinting capabilities to automate an ultra-violet nanoimprint lithography (UV-NIL) process. The FPM is articulated from a novel 3-legged prismatic-prismatic-spherical (3PPS) parallel-kinematic configuration to deliver a θx–θy–Z motion. The developed FPM achieves a positioning and orientation resolution of ±10nm and 0.05″ respectively, and a continuous output force of 150N/Amp throughout a large workspace of 5°×5°×5mm. Part I mainly focuses on a new theoretical model that is used to analyze the stiffness characteristics of the compliant joint modules that formed the FPM, and experimental evaluations of each compliant joint module. Part II presents the stiffness modeling of the FPM, the performance evaluations of the developed prototype, and the preliminary results of the UV-NIL process.

Do vertebral derotation techniques offer better outcomes compared to traditional methods in the surgical treatment of adolescent idiopathic scoliosis?

In recent years, authors have described novel derotation techniques for surgery in adolescent idiopathic scoliosis. These methods include direct vertebral body derotation (DVD) and vertebral coplanar alignment (VCA). By improved derotation it is hoped that there is further reduction in rib hump prominence and corresponding improvement in patients' quality of life. This paper aims to evaluate studies reporting outcomes from DVD and VCA techniques to assess if these methods lead to superior radiographic vertebral derotation, rib hump correction on surface measurements or patient-reported outcomes compared to traditional derotation manoeuvres using similar instrumentation. Literature review. Fifteen reports were identified. Most comparative studies represent class three or four data. DVD and VCA techniques have been shown to reduce apical vertebral rotation by 37-63 %. Few studies compare DVD/VCA techniques with traditional methods. Most DVD/VCA reports with pedicle screw instrumentation have reported superior radiographic derotation on CT compared with conventional techniques. Despite this the majority of studies have found similar corrections of rib hump measurements between DVD/VCA techniques and cantilever or global derotation methods. There is no evidence that DVD/VCA techniques allow greater correction of significant rib hump deformity without an adjuvant thoracoplasty. No studies to date have used patient-reported outcomes prospectively or demonstrated clinically meaningful differences retrospectively between DVD/VCA and conventional techniques. There is little evidence to recommend the widespread adoption of DVD/VCA techniques. Whilst there is some weak evidence to suggest that novel techniques may improve radiographic measures, there is little to suggest that they offer patients improved correction of clinical rib hump or quality of life compared to established techniques. Further well-designed prospective studies are needed in this area.

Development of a High Precision Edge Alignment System for Touch-Panel Glass Substrates

There are two kinds of alignment systems, marked and unmarked. The glass substrate for touch panels is categorized as an unmarked work piece. Vision based glass substrate alignment (GSA) relies on the edge of the glass. Traditional GSA systems compensate first for angular and then for linear error. This reduces alignment accuracy and increases alignment time and edge detection usually takes longer than 10 ms. This study proposes an effortless edge detection method. This method is very simple and can significantly reduce the time taken to detect the edge to about 6 ms using a 1.3 megapixel image. In this study, a floating center idea is used to control the glass substrate on a high precision coplanar XXY alignment stage. According to the method, users can set the rotation center anywhere as long as it is on the working ( xy) plane. Tolerance prognosis is also considered in this study to help the operator decide if the substrate is usable or should be rejected. The experimental results show alignment repeatability of the x, y, and θ axes to be 1 μm, 1 μm, and 5 arcsec, respectively.

Swi5-Sfr1 protein stimulates Rad51-mediated DNA strand exchange reaction through organization of DNA bases in the presynaptic filament

The Swi5-Sfr1 heterodimer protein stimulates the Rad51-promoted DNA strand exchange reaction, a crucial step in homologous recombination. To clarify how this accessory protein acts on the strand exchange reaction, we have analyzed how the structure of the primary reaction intermediate, the Rad51/single-stranded DNA (ssDNA) complex filament formed in the presence of ATP, is affected by Swi5-Sfr1. Using flow linear dichroism spectroscopy, we observe that the nucleobases of the ssDNA are more perpendicularly aligned to the filament axis in the presence of Swi5-Sfr1, whereas the bases are more randomly oriented in the absence of Swi5-Sfr1. When using a modified version of the natural protein where the N-terminal part of Sfr1 is deleted, which has no affinity for DNA but maintained ability to stimulate the strand exchange reaction, we still observe the improved perpendicular DNA base orientation. This indicates that Swi5-Sfr1 exerts its activating effect through interaction with the Rad51 filament mainly and not with the DNA. We propose that the role of a coplanar alignment of nucleobases induced by Swi5-Sfr1 in the presynaptic Rad51/ssDNA complex is to facilitate the critical matching with an invading double-stranded DNA, hence stimulating the strand exchange reaction.

CsPbCO3F: A Strong Second-Harmonic Generation Material Derived from Enhancement via p−π Interaction

The combination of Pb(2+) cations with lone-pair electrons and F(-) anions with the largest electronegativity into the carbonate generates a new nonlinear optical material, CsPbCO3F, with the largest powder second-harmonic generation (SHG) response among carbonates of about 13.4 times that of KDP (KH2PO4), and transparency over the near-UV to middle-IR region. The optical characterization of the compound indicates that it is phase matchable. Its crystal structure exhibits the stacking of [CsF]∞ and [Pb(CO3)]∞ layers, and the coplanar alignment of [CO3] triangles which are oriented in the same direction. Yet the Pb(2+) cation has an inert or nonstereoactive lone-pair, as indicated by its more spherical shape. Theoretical calculations confirm that the extremely large SHG efficiency indeed originates from enhancement via p-π interaction between Pb(2+) and [CO3](2-) within the [Pb(CO3)] layers.