426 research outputs found
Short anterior correction of the thoracolumbar/lumbar curve in King 1 idiopathic scoliosis: the behaviour of the instrumented and non-instrumented curves and the trunk balance
This is a retrospective clinical, radiological and patient outcome assessment of 21 consecutive patients with King 1 idiopathic adolescent scoliosis treated by short anterior selective fusion of the major thoracolumbar/lumbar (TL/L) curve. Three-dimensional changes of both curves, changes in trunk balance and rib hump were evaluated. The minimal follow-up was 24months (max. 83). The Cobb angle of the TL/L curve was 52° (45-67°) with a flexibility of 72% (40-100%). The average length of the main curve was 5 (3-8) segments. An average of 3 (2-4) segments was fused using rigid single rod implants with side-loading screws. The Cobb angle of the thoracic curve was 33° (18-50°) with a flexibility of 69% (29-100%). The thoracic curve in bending was less than 20° in 17 patients, and 20-25° in 4 patients. In the TL/L curve there was an improvement of the Cobb angle of 67%, of the apex vertebral rotation of 51% and of the apex vertebral translation of 74%. The Cobb angle of the thoracic curve improved 29% spontaneously. Shoulder balance improved significantly from an average preoperative imbalance of 14.5-3.1mm at the last follow-up. Seventy-five percent of the patients with preoperative positive shoulder imbalance (higher on the side of the thoracic curve) had levelled shoulders at the last follow-up. C7 offset improved from a preoperative 19.8 (0-40)to 4.8 (0-18) mm at the last follow-up. There were no significant changes in rotation, translation of the thoracic curve and the clinical rib hump. There were no significant changes in thoracic kyphosis or lumbar lordosis. The average score of the SRS-24 questionnaire at the last follow-up was 91 points (max. 120). We conclude that short anterior selective fusion of the TL/L curve in King 1 scoliosis with a thoracic curve bending to 25° or less (Type 5 according to Lenke classification) results in a satisfactory correction and a balanced spine. Short fusions leave enough mobile lumbar segments for the establishment of global spinal balance. A positive shoulder imbalance is not a contraindication for this procedure. Structural interbody grafts are not necessary to maintain lumbar lordosi
Recommended from our members
Distinct Surface and Bulk Thermal Behaviors of LiNi0.6Mn0.2Co0.2O2 Cathode Materials as a Function of State of Charge.
Understanding how structural and chemical transformations take place in particles under thermal conditions can inform designing thermally robust electrode materials. Such a study necessitates the use of diagnostic techniques that are capable of probing the transformations at multiple length scales and at different states of charge (SOC). In this study, the thermal behavior of LiNi0.6Mn0.2Co0.2O2 (NMC-622) was examined as a function of SOC, using an array of bulk and surface-sensitive techniques. In general, thermal stability decreases as lithium content is lowered and conversion in the bulk to progressively reduced metal oxides (spinels, rock salt) occurs as the temperature is raised. Hard X-ray absorption spectroscopy (XAS) and X-ray Raman spectroscopy (XRS) experiments, which probe the bulk, reveal that Ni and Co are eventually reduced when partially delithiated samples (regardless of the SOC) are heated, although Mn is not. Surface-sensitive synchrotron techniques, such as soft XAS and transmission X-ray microscopy (TXM), however, reveal that for 50% delithiated samples, apparent oxidation of nickel occurs at particle surfaces under some circumstances. This is partially compensated by reduction of cobalt but may also be a consequence of redistribution of lithium ions upon heating. TXM results indicate the movement of reduced nickel ions into particle interiors or oxidized nickel ions to the surface or both. These experiments illustrate the complexity of the thermal behavior of NMC cathode materials. The study also informs the importance of investigating the surface and bulk difference as a function of SOC when studying the thermal behaviors of battery materials
Remarkable Effect on Thermosensitive Behavior Regarding Alkylation at the Amide Position of Poly(N-vinylamide)s
N-Vinylamide derivatives, such as N-n-butyl-N-vinylformamides and N-iso-butyl-N-vinylformamides were synthesized and copolymerized with N-vinylformamide and N-methyl-N-vinylacetamide. Lower critical solution temperature values of the copolymers were observed at a wide range of temperatures. Thermosensitive behaviors of copolymers were controlled not only by the induction rate of alkylation of N-vinylamides at the amide position but also by the chemical structures, including hydrogen atom of secondary amide group
Directed evolution of cytochrome c for carbon–silicon bond formation: Bringing silicon to life
Organic compounds containing silicon are important for a number of applications, from polymers to semiconductors. The catalysts used for creating carbon-silicon bonds, however, often require expensive trace metals or have limited lifetimes. Borrowing from the ability of some metallo-enzymes to catalyze other rare carbene insertion reactions, Kan et al. used heme proteins to form carbon-silicon bonds across a range of conditions and substrates (see the Perspective by Klare and Oestreich). Directed evolution experiments using cytochrome c from Rhodothermus marinus improved the reaction to be 15 times more efficient than industrial catalysts
Potential Therapeutic Applications of Exosomes in Bone Regenerative Medicine
The ability of bone regeneration is relatively robust, which is crucial for fracture healing, but delayed healing and nonunion are still common problems in clinical practice. Fortunately, exciting results have been achieved for regenerative medicine in recent years, especially in the area of stem cell-based treatment, but all these cell-based approaches face challenging problems, including immune rejection. For this reason, exosomes, stem cell-derived small vesicles of endocytic origin, have attracted the attention of many investigators in the field of bone regeneration. One of the attractive features of exosomes is that they are small and can travel between cells and deliver bioactive products, including miRNA, mRNA, proteins, and various other factors, to promote bone regeneration, with undetectable immune rejection. In this chapter, we intend to briefly update the recent progressions, and discuss the potential challenges in the target areas. Hopefully, our discussion would be helpful not only for the clinicians and the researchers in the specific disciplines but also for the general audiences as well
A GPU-Parallelized Interpolation-Based Fast Multipole Method for the Relativistic Space-Charge Field Calculation
The fast multipole method (FMM) has received growing attention in the beam
physics simulation. In this study, we formulate an interpolation-based FMM for
the computation of the relativistic space-charge field. Different to the
quasi-electrostatic model, our FMM is formulated in the lab-frame and can be
applied without the assistance of the Lorentz transformation. In particular, we
derive a modified admissibility condition which can effectively control the
interpolation error of the proposed FMM. The algorithms and their GPU
parallelization are discussed in detail. A package containing serial and
GPU-parallelized solvers is implemented in the Julia programming language. The
GPU-parallelized solver can reach a speedup of more than a hundred compared to
the execution on a single CPU core.Comment: 30 pages, 10 figure
OAG-BERT: Pre-train Heterogeneous Entity-augmented Academic Language Models
To enrich language models with domain knowledge is crucial but difficult.
Based on the world's largest public academic graph Open Academic Graph (OAG),
we pre-train an academic language model, namely OAG-BERT, which integrates
massive heterogeneous entities including paper, author, concept, venue, and
affiliation. To better endow OAG-BERT with the ability to capture entity
information, we develop novel pre-training strategies including heterogeneous
entity type embedding, entity-aware 2D positional encoding, and span-aware
entity masking. For zero-shot inference, we design a special decoding strategy
to allow OAG-BERT to generate entity names from scratch. We evaluate the
OAG-BERT on various downstream academic tasks, including NLP benchmarks,
zero-shot entity inference, heterogeneous graph link prediction, and author
name disambiguation. Results demonstrate the effectiveness of the proposed
pre-training approach to both comprehending academic texts and modeling
knowledge from heterogeneous entities. OAG-BERT has been deployed to multiple
real-world applications, such as reviewer recommendations and paper tagging in
the AMiner system. It is also available to the public through the CogDL
package
- …