Multi-angle laser device improves novice learning of C-arm fluoroscopy for lumbar spine surgery.

PURPOSE: This study aims to evaluate the efficacy and satisfaction of using a multi-angle laser device (MLD) for C-arm fluoroscopy to assist novice learners during lumbar spine surgery. METHODS: Forty novice learners were randomly assigned to Group A using an MLD-equipped C-arm or Group B using a traditional C-arm. Both groups performed X-ray fluoroscopy on a lumbar spine model in supine and rotated positions. Time, number of shots, and deviation from the target were compared. A questionnaire was used to assess the learning experience. RESULTS: Group A required less time (13.66 vs. 25.63 min), and fewer shots (15.05 vs. 32.50), and had a smaller deviation (22.9% vs. 61.5%) than Group B (all p<0.05). The questionnaire revealed higher scores in Group A for comfort, efficiency, and knowledge mastery (all p<0.05). CONCLUSION: The MLD significantly improves novice learning of C-arm fluoroscopy during lumbar spine surgery.

Design of High-Entropy Tape Electrolytes for Compression-Free Solid-State Batteries.

Advanced solid electrolytes with strong adhesion to other components are the key for the successes of solid-state batteries. Unfortunately, traditional solid electrolytes have to work under high compression to maintain the contact inside owing to their poor adhesion. Here, a concept of high-entropy tape electrolyte (HETE) is proposed to simultaneously achieve tape-like adhesion, liquid-like ion conduction, and separator-like mechanical properties. This HETE is designed with adhesive skin layer on both sides and robust skeleton layer in the middle. The significant properties of the three layers are enabled by high-entropy microstructures which are realized by harnessing polymer-ion interactions. As a result, the HETE shows high ionic conductivity (3.50 ± 0.53 × 10-4 S cm-1 at room temperature), good mechanical properties (toughness 11.28 ± 1.12 MJ m-3, strength 8.18 ± 0.28 MPa), and importantly, tape-like adhesion (interfacial toughness 231.6 ± 9.6 J m-2). Moreover, a compression-free solid-state tape battery is finally demonstrated by adhesion-based assembling, which shows good interfacial and electrochemical stability even under harsh mechanical conditions, such as twisting and bending. The concept of HETE and compression-free solid-state tape batteries may bring promising solutions and inspiration to conquer the interface challenges in solid-state batteries and their manufacturing.

Architecting the Microenvironment Skeleton of Active Materials in High-Capacity Electrodes by Self-Assembled Nano-Building Blocks.

In analogy to the cell microenvironment in biology, understanding and controlling the active-material microenvironment (ME@AM) microstructures in battery electrodes is essential to the successes of energy storage devices. However, this is extremely difficult for especially high-capacity active materials (AMs) like sulfur, due to the poor controlling on the electrode microstructures. To conquer this challenge, here, a semi-dry strategy based on self-assembled nano-building blocks is reported to construct nest-like robust ME@AM skeleton in a solvent-and-stress-less way. To do that, poly(vinylidene difluoride) nanoparticle binder is coated onto carbon-nanofibers (NB@CNF) via the nanostorm technology developed in the lab, to form self-assembled nano-building blocks in the dry slurry. After compressed into an electrode prototype, the self-assembled dry-slurry is then bonded by in-situ nanobinder solvation. With this strategy, mechanically strong thick sulfur electrodes are successfully fabricated without cracking and exhibit high capacity and good C-rate performance even at a high AM loading (25.0 mg cm-2 by 90 wt% in the whole electrode). This study may not only bring a promising solution to dry manufacturing of batteries, but also uncover the ME@AM structuring mechanism with nano-binder for guiding the design and control on electrode microstructures.

Mass Production of Customizable Core-Shell Active Materials in Seconds by Nano-Vapor Deposition for Advancing Lithium Sulfur Battery.

Rational design and scalable production of core-shell sulfur-rich active materials is vital for not only the practical success of future metal-sulfur batteries but also for a deep insight into the core-shell design for sulfur-based electrochemistry. However, this is a big challenge mainly due to the lack of efficient strategy for realizing precisely controlled core-shell structures. Herein, by harnessing the frictional heating and dispersion capability of the nanostorm technology developed in the authors' laboratory, it is surprisingly found that sulfur-rich active particles can be coated with on-demand shell nanomaterials in seconds. To understand the process, a micro-adhesion guided nano-vapor deposition (MAG-NVD) working mechanism is proposed. Enabled by this technology, customizable nano-shell is realized in a super-efficient and solvent-free way. Further, the different roles of shell characteristics in affecting the sulfur-cathode electrochemical performance are discovered and clarified. Last, large-scale production of calendaring-compatible cathode with the optimized core-shell active materials is demonstrated, and a Li-S pouch-cell with 453 Wh kg-1 @0.65 Ah is also reported. The proposed nano-vapor deposition may provide an attractive alternative to the well-known physical and chemical vapor deposition technologies.

Functional CNTs@EMIM+ -Br- Electrode Enabling Polysulfides Confining and Deposition Regulating for Solid-State Li-Sulfur Battery.

With an extremely high theoretical energy density, poly(ethylene oxide) (PEO)-based solid-state lithium-sulfur (Li-S) batteries are emerging as one of the most feasible and safest battery storage systems. However, the long-term cycling performance is severely impeded by polysulfides (Li2 Sn , n = 4-8) shuttling and terrible electrode passivation from the electronic insulating Li2 S. Here, a novel cathode through chemically grafted 1-Ethyl-3-methylimidazolium bromide (EMIM+ -Br- ) to carbon nanotube (CNTs) for PEO-based Li-S batteries is reported (CNTs@EMIM-Br/S). Concretely, bi-functional mediator EMIM+ -Br- not only inhibits the polysulfides shuttling by strong chemical interactions via EMIM+ , but also facilitates the electrochemical kinetics for promoting the formation of 3D particulate Li2 S through high donor anion (Br- ). Satisfactorily, dual-function CNTs@EMIM-Br/S cathode exhibits high sulfur utilization with the capacity of up to 1298 mAh g-1 , and keeps high capacity retention of 80.2% at 0.2 C after 350 cycles, exceeding that of many reported PEO-based solid-state Li-S batteries. This work will open a new door for rationally designed architecture to enable the practical applications of advanced Li-S batteries.

High-energy silicon-sulfurized poly(acrylonitrile) battery based on a nitrogen evolution reaction.

The practical application of high-energy lithium-sulfur battery is plagued with two deadly obstacles. One is the "shuttle effect" originated from the sulfur cathode, and the other is the low Coulombic efficiency and security issues arising from the lithium metal anode. In addressing these issues, we propose a novel silicon-sulfurized poly(acrylonitrile) full battery. In this lithium metal-free system, the Li source is pre-loaded in the cathode, using a nitrogen evolution reaction (NER) to implant Li+ into the silicon/carbon anode. Sulfurized poly(acrylonitrile) based on a solid-solid conversion mechanism can fundamentally circumvent the "shuttle effect". Meanwhile, the silicon/carbon anode can achieve more efficient utilization and higher security when compared with the Li metal anode. The full cell used in this technology can deliver a capacity of 1169.3 mAh g-1, and it can be stabilized over 100 cycles, implying its excellent electrochemical stability. Furthermore, the practical pouch cell with a high sulfur loading of 4.2 mg cm-2 can achieve a high specific energy of 513.2 Wh kg-1. The mechanism of the NER in cathode has also been investigated and analyzed by in situ methods. Notably, this battery design completely conforms to the current battery production technology because of the degassing of gasbag, resulting in a low manufacturing cost. This work will open the avenue to develop a lithium metal-free battery using the NER.

Biomimetic Microadhesion Guided Instant Spinning.

Animals create high-performance fibers at natural ambient conditions via a unique spinning process. In contrast, the spinning technologies developed by human beings are usually clumsy and require sophisticated skills. Here, inspired by adhesion-based silkworm spinning, we report a microadhesion guided (MAG) spinning technology for instant and on-demand fabrication of micro/nanofibers. Enabled by the adhesion between the spinning fluids and the microneedles, the MAG spinning can generate micro/nanofibers with programmable morphology. By further mimicking the head movement of the silkworm spinning, the MAG technology is extended with three different modes: straight, vibratory, and twisted spinning, which generate oriented fibers, hierarchical cross-linked fibers, and all-in-one fibers, respectively. Due to the prevalence of microadhesion and its unprecedented flexibility in operation, equipment-free MAG spinning is finally realized for instant fiber fabrication by only polymeric foams. Finally, the MAG spinning is demonstrated as a promising instant technology for emergent applications, such as wound dressing.

Evaluation of left ventricular function, rotation, twist and untwist in patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a disease with an autosomal-dominant pattern of inheritance associated with a variety of disease courses, age of onset, symptom severity, left ventricular outflow obstruction and risk for sudden cardiac death. Left ventricular systolic function is typically normal in most HCM patients using conventional echocardiographic indexes; however, myocardial systolic and diastolic function are reduced, and the mechanism of myocardial dysfunction remains unclear. Echocardiography is an invaluable tool for the diagnosis and assessment of hemodynamic condition, evaluation of therapy and outcome, and follow-up of patients with HCM. The recent advent of speckle tracking imaging provides a novel index for the noninvasive assessment of left ventricular myocardial dysfunction, and has been confirmed by many studies. A search for original articles focusing on HCM and its associated twist and untwist mechanisms was performed in the MEDLINE and PubMed databases with no date restrictions. All articles identified were English-language, full-text publications. The reference lists of identified articles were also searched for additional articles and reviews.