Exploring Layered Disorder in Lithium-Ion-Conducting Li3Y1-xInxCl6.

Li3Y1-xInxCl6 undergoes a phase transition from trigonal to monoclinic via an intermediate orthorhombic phase. Although the trigonal yttrium containing the end member phase, Li3YCl6, synthesized by a mechanochemical route, is known to exhibit stacking fault disorder, not much is known about the monoclinic phases of the serial composition Li3Y1-xInxCl6. This work aims to shed light on the influence of the indium substitution on the phase evolution, along with the evolution of stacking fault disorder using X-ray and neutron powder diffraction together with solid-state nuclear magnetic resonance spectroscopy, studying the lithium-ion diffusion. Although Li3Y1-xInxCl6 with x ≤ 0.1 exhibits an ordered trigonal structure like Li3YCl6, a large degree of stacking fault disorder is observed in the monoclinic phases for the x ≥ 0.3 compositions. The stacking fault disorder materializes as a crystallographic intergrowth of faultless domains with staggered layers stacked in a uniform layer stacking, along with faulted domains with randomized staggered layer stacking. This work shows how structurally complex even the "simple" series of solid solutions can be in this class of halide-based lithium-ion conductors, as apparent from difficulties in finding a consistent structural descriptor for the ionic transport.

OptoChamber: A Low-cost, Easy-to-Make, Customizable, and Multi-Chambered Electronic Device for Applying Optogenetic Stimulation to Larval Drosophila melanogaster.

Optogenetics is a powerful tool used to manipulate physiological processes in animals through cell-specific expression of genetically modified channelrhodopsins. In Drosophila melanogaster, optogenetics is frequently used for temporal control of neuronal activation or silencing through light-dependent actuation of cation and anion channelrhodopsins, respectively. The high setup costs and complexity associated with commercially available optogenetic systems prevents many investigators from exploring the use of this technology. We developed a low-cost, customizable, and easy-to-make optogenetics chamber (OptoChamber) and verified its functionality in a robust cellular assay: activity-dependent remodeling of larval motor neurons in Drosophila embryos.

Posterior Transdural Approach for Thoracic Corpectomies in the Setting of Complex Spine Deformity Reconstruction.

BACKGROUND AND OBJECTIVE: There are many surgical approaches for execution of a thoracic corpectomy. In cases of challenging deformity, traditional posterior approaches might not be sufficient to complete the resection of the vertebral body. In this technical note, we describe indications and technique for a transdural multilevel high thoracic corpectomy. METHODS: A 25-year-old man with a history of neurofibromatosis type 1 presented with instrumentation failure after a previous T1-T12 posterior spinal fusion, extensive laminectomy, and tumor resection. The patient presented with progressive back pain, had broad dural ectasia, and a progressive kyphotic rotational and anteriorly translated spinal deformity. To resect the medial-most aspect of the vertebral body, a bilateral extracavitary approach was attempted, but was found insufficient. A transdural approach was subsequently performed. A left paramedian durotomy was made, followed by generous arachnoid dissection, bilateral dentate ligament division, and T4 rootlet sacrifice to mobilize the spinal cord. A ventral durotomy was then made and the ventral dura was reflected over the spinal cord to protect it while drilling. The corpectomy was then completed. The ventral and dorsal durotomies were closed primarily and reinforced with fibrin glue and fibrin sealant patch. The corpectomy defect was filled with nonstructural autograft. RESULTS: The focal kyphosis was corrected with a combination of rod contouring, compression, and in situ bending. During the surgery, the patient had stable neuromonitoring data, and postoperatively had no neurological deficits. On follow-up until 1 year, the patient presented with no signs of cerebrospinal spinal leaks, no motor or sensory deficits, minimal incisional pain, and significantly improved posture. CONCLUSION: Complex high thoracic (T3-5) ventral pathology inaccessible via a bilateral extracavitary approach may be accessed via a transdural approach as opposed to an anterior/lateral transthoracic approach that requires mobilization of cardiovascular structures or scapula.

Charge Regulation at the Nanoscale as Evidenced from Light-Responsive Nanoemulsions.

Emulsions are indispensable in everyday life, and the demand for emulsions' diversity and control of properties is therefore substantial. As emulsions possess a high internal surface area, an understanding of the oil/water (o/w) interfaces at the molecular level is fundamental but often impaired by experimental limitations to probe emulsion interfaces in situ. Here, we have used light-responsive surfactants (butyl-AAP) that can photoisomerize between E and Z isomers by visible and UV light irradiation to tune the emulsion interfaces. This causes massive changes in the interface tension at the extended o/w interfaces in macroemulsions and a drastic shift in the surfactants' critical micelle concentration, which we show can be used to control both the stability and phase separation. Strikingly different from macroemulsions are nanoemulsions (RH ∼90 nm) as these are not susceptible to E/Z photoisomerization of the surfactants in terms of changes in their droplet size or ζ-potential. However, in situ second-harmonic scattering and pulsed-field gradient nuclear magnetic resonance (NMR) experiments show dramatic and reversible changes in the surface excess of surfactants at the nanoscopic interfaces. The apparent differences in ζ-potentials and surface excess provide evidence for a fixed charge to particle size ratio and the need for counterion condensation to renormalize the particle charge to a critical charge, which is markedly different compared to the behavior of very large particles in macroemulsions. Thus, our findings may have broader implications as the electrostatic stabilization of nanoparticles requires much lower surfactant concentrations, allowing for a more sustainable use of surfactants.

Utilization of Augmented Reality Head-Mounted Display for the Surgical Management of Thoracolumbar Spinal Trauma.

Background and Objectives: Augmented reality head-mounted display (AR-HMD) is a novel technology that provides surgeons with a real-time CT-guided 3-dimensional recapitulation of a patient's spinal anatomy. In this case series, we explore the use of AR-HMD alongside more traditional robotic assistance in surgical spine trauma cases to determine their effect on operative costs and perioperative outcomes. Materials and Methods: We retrospectively reviewed trauma patients who underwent pedicle screw placement surgery guided by AR-HMD or robotic-assisted platforms at an academic tertiary care center between 1 January 2021 and 31 December 2022. Outcome distributions were compared using the Mann-Whitney U test. Results: The AR cohort (n = 9) had a mean age of 66 years, BMI of 29.4 kg/m2, Charlson Comorbidity Index (CCI) of 4.1, and Surgical Invasiveness Index (SII) of 8.8. In total, 77 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 378 mL, 0.78 units transfused, 398 min spent in the operating room, and a 20-day LOS. The robotic cohort (n = 13) had a mean age of 56 years, BMI of 27.1 kg/m2, CCI of 3.8, and SII of 14.2. In total, 128 pedicle screws were placed in this cohort. Intra-operatively, there was a mean blood loss of 432 mL, 0.46 units transfused units used, 331 min spent in the operating room, and a 10.4-day LOS. No significant difference was found between the two cohorts in any outcome metrics. Conclusions: Although the need to address urgent spinal conditions poses a significant challenge to the implementation of innovative technologies in spine surgery, this study represents an initial effort to show that AR-HMD can yield comparable outcomes to traditional robotic surgical techniques. Moreover, it highlights the potential for AR-HMD to be readily integrated into Level 1 trauma centers without requiring extensive modifications or adjustments.

Virtual, Augmented, and Mixed Reality Applications for Surgical Rehearsal, Operative Execution, and Patient Education in Spine Surgery: A Scoping Review.

Background and Objectives: Advances in virtual reality (VR), augmented reality (AR), and mixed reality (MR) technologies have resulted in their increased application across many medical specialties. VR's main application has been for teaching and preparatory roles, while AR has been mostly used as a surgical adjunct. The objective of this study is to discuss the various applications and prospects for VR, AR, and MR specifically as they relate to spine surgery. Materials and Methods: A systematic review was conducted to examine the current applications of VR, AR, and MR with a focus on spine surgery. A literature search of two electronic databases (PubMed and Scopus) was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The study quality was assessed using the MERSQI score for educational research studies, QUACS for cadaveric studies, and the JBI critical appraisal tools for clinical studies. Results: A total of 228 articles were identified in the primary literature review. Following title/abstract screening and full-text review, 46 articles were included in the review. These articles comprised nine studies performed in artificial models, nine cadaveric studies, four clinical case studies, nineteen clinical case series, one clinical case-control study, and four clinical parallel control studies. Teaching applications utilizing holographic overlays are the most intensively studied aspect of AR/VR; the most simulated surgical procedure is pedicle screw placement. Conclusions: VR provides a reproducible and robust medium for surgical training through surgical simulations and for patient education through various platforms. Existing AR/MR platforms enhance the accuracy and precision of spine surgeries and show promise as a surgical adjunct.

A Comprehensive Investigation of Active Learning Strategies for Conducting Anti-Cancer Drug Screening.

It is well-known that cancers of the same histology type can respond differently to a treatment. Thus, computational drug response prediction is of paramount importance for both preclinical drug screening studies and clinical treatment design. To build drug response prediction models, treatment response data need to be generated through screening experiments and used as input to train the prediction models. In this study, we investigate various active learning strategies of selecting experiments to generate response data for the purposes of (1) improving the performance of drug response prediction models built on the data and (2) identifying effective treatments. Here, we focus on constructing drug-specific response prediction models for cancer cell lines. Various approaches have been designed and applied to select cell lines for screening, including a random, greedy, uncertainty, diversity, combination of greedy and uncertainty, sampling-based hybrid, and iteration-based hybrid approach. All of these approaches are evaluated and compared using two criteria: (1) the number of identified hits that are selected experiments validated to be responsive, and (2) the performance of the response prediction model trained on the data of selected experiments. The analysis was conducted for 57 drugs and the results show a significant improvement on identifying hits using active learning approaches compared with the random and greedy sampling method. Active learning approaches also show an improvement on response prediction performance for some of the drugs and analysis runs compared with the greedy sampling method.

Pressure-Induced Dislocations and Their Influence on Ionic Transport in Li+-Conducting Argyrodites.

The influence of the microstructure on the ionic conductivity and cell performance is a topic of broad scientific interest in solid-state batteries. The current understanding is that interfacial decomposition reactions during cycling induce local strain at the interfaces between solid electrolytes and the anode/cathode, as well as within the electrode composites. Characterizing the effects of internal strain on ion transport is particularly important, given the significant local chemomechanical effects caused by volumetric changes of the active materials during cycling. Here, we show the effects of internal strain on the bulk ionic transport of the argyrodite Li6PS5Br. Internal strain is reproducibly induced by applying pressures with values up to 10 GPa. An internal permanent strain is observed in the material, indicating long-range strain fields typical for dislocations. With increasing dislocation densities, an increase in the lithium ionic conductivity can be observed that extends into improved ionic transport in solid-state battery electrode composites. This work shows the potential of strain engineering as an additional approach for tuning ion conductors without changing the composition of the material itself.

Cove-Edged Chiral Graphene Nanoribbons with Chirality-Dependent Bandgap and Carrier Mobility.

Graphene nanoribbons (GNRs) have garnered significant interest due to their highly customizable physicochemical properties and potential utility in nanoelectronics. Besides controlling widths and edge structures, the inclusion of chirality in GNRs brings another dimension for fine-tuning their optoelectronic properties, but related studies remain elusive owing to the absence of feasible synthetic strategies. Here, we demonstrate a novel class of cove-edged chiral GNRs (CcGNRs) with a tunable chiral vector (n,m). Notably, the bandgap and effective mass of (n,2)-CcGNR show a distinct positive correlation with the increasing value of n, as indicated by theory. Within this GNR family, two representative members, namely, (4,2)-CcGNR and (6,2)-CcGNR, are successfully synthesized. Both CcGNRs exhibit prominently curved geometries arising from the incorporated [4]helicene motifs along their peripheries, as also evidenced by the single-crystal structures of the two respective model compounds (1 and 2). The chemical identities and optoelectronic properties of (4,2)- and (6,2)-CcGNRs are comprehensively investigated via a combination of IR, Raman, solid-state NMR, UV-vis, and THz spectroscopies as well as theoretical calculations. In line with theoretical expectation, the obtained (6,2)-CcGNR possesses a low optical bandgap of 1.37 eV along with charge carrier mobility of ∼8 cm2 V-1 s-1, whereas (4,2)-CcGNR exhibits a narrower bandgap of 1.26 eV with increased mobility of ∼14 cm2 V-1 s-1. This work opens up a new avenue to precisely engineer the bandgap and carrier mobility of GNRs by manipulating their chiral vector.

Pushing the Detection Limit of Static Wideline NMR Spectroscopy Using Ultrafast Frequency-Swept Pulses.

We report a simple design strategy for wideband uniform-rate smooth truncation (WURST) pulses that enables ultrafast frequency sweeps to maximize the sensitivity of Carr-Purcell-Meiboom-Gill (CPMG) acquisition in static wideline nuclear magnetic resonance (NMR). Three compelling examples showcase the advantage of ultrafast frequency sweeps over currently employed WURST-CPMG protocols, demonstrating the potential of investigating materials that are typically inaccessible to static wideline NMR techniques, e.g., paramagnetic solids with short homogeneous transverse relaxation times.

Curved graphene nanoribbons derived from tetrahydropyrene-based polyphenylenes via one-pot K-region oxidation and Scholl cyclization.

Precise synthesis of graphene nanoribbons (GNRs) is of great interest to chemists and materials scientists because of their unique opto-electronic properties and potential applications in carbon-based nanoelectronics and spintronics. In addition to the tunable edge structure and width, introducing curvature in GNRs is a powerful structural feature for their chemi-physical property modification. Here, we report an efficient solution synthesis of the first pyrene-based GNR (PyGNR) with curved geometry via one-pot K-region oxidation and Scholl cyclization of its corresponding well-soluble tetrahydropyrene-based polyphenylene precursor. The efficient A2B2-type Suzuki polymerization and subsequent Scholl reaction furnishes up to ∼35 nm long curved GNRs bearing cove- and armchair-edges. The construction of model compound 1, as a cutout of PyGNR, from a tetrahydropyrene-based oligophenylene precursor proves the concept and efficiency of the one-pot K-region oxidation and Scholl cyclization, which is clearly revealed by single crystal X-ray diffraction analysis. The structure and optical properties of PyGNR are investigated by Raman, FT-IR, solid-state NMR, STM and UV-Vis analysis with the support of DFT calculations. PyGNR exhibits a narrow optical bandgap of ∼1.4 eV derived from a Tauc plot, qualifying as a low-bandgap GNR. Moreover, THz spectroscopy on PyGNR estimates its macroscopic charge mobility µ as ∼3.6 cm2 V-1 s-1, outperforming several other curved GNRs reported via conventional Scholl reaction.

On the Discrepancy between Local and Average Structure in the Fast Na+ Ionic Conductor Na2.9Sb0.9W0.1S4.

Aliovalent substitution is a common strategy to improve the ionic conductivity of solid electrolytes for solid-state batteries. The substitution of SbS43- by WS42- in Na2.9Sb0.9W0.1S4 leads to a very high ionic conductivity of 41 mS cm-1 at room temperature. While pristine Na3SbS4 crystallizes in a tetragonal structure, the substituted Na2.9Sb0.9W0.1S4 crystallizes in a cubic phase at room temperature based on its X-ray diffractogram. Here, we show by performing pair distribution function analyses and static single-pulse 121Sb NMR experiments that the short-range order of Na2.9Sb0.9W0.1S4 remains tetragonal despite the change in the Bragg diffraction pattern. Temperature-dependent Raman spectroscopy revealed that changed lattice dynamics due to the increased disorder in the Na+ substructure leads to dynamic sampling causing the discrepancy in local and average structure. While showing no differences in the local structure, compared to pristine Na3SbS4, quasi-elastic neutron scattering and solid-state 23Na nuclear magnetic resonance measurements revealed drastically improved Na+ diffusivity and decreased activation energies for Na2.9Sb0.9W0.1S4. The obtained diffusion coefficients are in very good agreement with theoretical values and long-range transport measured by impedance spectroscopy. This work demonstrates the importance of studying the local structure of ionic conductors to fully understand their transport mechanisms, a prerequisite for the development of faster ionic conductors.

Plasma-Enabled Graphene Quantum Dot Hydrogels as Smart Anticancer Drug Nanocarriers.

One of the major challenges on the way to low-cost, simple, and effective cancer treatments is the lack of smart anticancer drug delivery materials with the requisite of site-specific and microenvironment-responsive properties. This work reports the development of plasma-engineered smart drug nanocarriers (SDNCs) containing chitosan and nitrogen-doped graphene quantum dots (NGQDs) for drug delivery in a pH-responsive manner. Through a customized microplasma processing, a highly cross-linked SDNC with only 4.5% of NGQD ratio can exhibit enhanced toughness up to threefold higher than the control chitosan group, avoiding the commonly used high temperatures and toxic chemical cross-linking agents. The SDNCs demonstrate improved loading capability for doxorubicin (DOX) via π-π interactions and stable solid-state photoluminescence to monitor the DOX loading and release through the Förster resonance energy transfer (FRET) mechanism. Moreover, the DOX loaded SDNC exhibits anticancer effects against cancer cells during cytotoxicity tests at minimum concentration. Cellular uptake studies confirm that the DOX loaded SDNC can be successfully internalized into the nucleus after 12 h incubation period. This work provides new insights into the development of smart, environmental-friendly, and biocompatible nanographene hydrogels for the next-generation biomedical applications.

Structural characterization of a new fluorophosphotellurite glass system.

While phosphotellurite glasses have superior properties over SiO2-based glasses for many applications in optoelectronics and photonic devices, their high hydroxyl content limits their use in the mid-infrared range. This drawback can be overcome by fluoride addition to the formulation. In this work, we report the preparation, optical, and structural characterization of new glasses in the ternary system TeO2-xNaF-NaPO3 having the compositions 0.8TeO2-0.2[xNaF-(1 - x)NaPO3] and 0.6TeO2-0.4[xNaF-(1 - x)NaPO3] (0 ≤ x ≤ 1) obtained by the traditional melt-quenching method and labeled as T8NNx and T6NNx, respectively. Differential scanning calorimetry (DSC) reveals high thermal stability against crystallization, with Tx-Tg varying from 80 to 130 °C, depending on fluoride/phosphate ratios. Raman spectroscopy suggests that the network connectivity increases with increasing phosphate concentration. 125Te, 23Na, 31P, and 19F NMR spectroscopy provides detailed structural information about Te-O-P, Te-F, Te-O-Te, P-O-P, and P-F linkages and the charge compensation mechanism for the sodium ions. The present study is the first comprehensive structural characterization of a fluorophosphotellurite glass system.

Generation of boryl-nitroxide radicals from a boraalkene via the nitroso ene reaction.

Examples of isolated boron substituted nitroxide radicals are rare. The reaction of the reactive cyclic boraalkene 3 with nitrosobenzene yields a mixture of the [2 + 2] cycloaddition product 4a, the B-nitroxide radicals 5a and 6a and the azoxybenzene co-product 7avia a bora nitroso ene reaction pathway, the boron analogue of the nitroso ene reaction. The products were separated by flash chromatography, and the B-nitroxide radicals were characterized by X-ray diffraction and EPR spectroscopy. Radical 5a was shown to be a hydrogen atom abstractor. Both the B-nitroxide radicals are more easily oxidized compared to e.g. TEMPO, as shown by cyclic voltammetry.

Plasma Nanoengineering of Bioresource-Derived Graphene Quantum Dots as Ultrasensitive Environmental Nanoprobes.

Environmental contamination and energy shortage are among the most critical global issues that require urgent solutions to ensure sustainable ecological balance. Rapid and ultrasensitive monitoring of water quality against pollutant contaminations using a low-cost, easy-to-operate, and environmentally friendly technology is a promising yet not commonly available solution. Here, we demonstrate the effective use of plasma-converted natural bioresources for environmental monitoring. The energy-efficient microplasmas operated at ambient conditions are used to convert diverse bioresources, including fructose, chitosan, citric acid, lignin, cellulose, and starch, into heteroatom-doped graphene quantum dots (GQDs) with controlled structures and functionalities for applications as fluorescence-based environmental nanoprobes. The simple structure of citric acid enables the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent emissions, while the saccharides including fructose, chitosan, lignin, cellulose, and starch allow the synthesis of GQDs with excitation-dependent emissions due to broader size distribution. Moreover, the presence of heteroatoms such as N and/or S in the chemical structures of chitosan and lignin coupled with the highly reactive species generated by the plasma facilitates the one-step synthesis of N, S-codoped GQDs, which offer selective detection of toxic environmental contaminants with a low limit of detection of 7.4 nM. Our work provides an insight into the rapid and green fabrication of GQDs with tunable emissions from natural resources in a scalable and sustainable manner, which is expected to generate impact in the environmental safety, energy conversion and storage, nanocatalysis, and nanomedicine fields.

Oxy-Borylenes as Photoreductants: Synthesis and Application in Dehalogenation and Detosylation Reactions.

While the range of accessible borylenes has significantly broadened over the last decade, applications remain limited. Herein, we present tricoordinate oxy-borylenes as potent photoreductants that can be readily activated by visible light. Facile oxidation of CAAC stabilized oxy-borylenes (CAAC)(IPr2 Me2 )BOR (R=TMS, CH2 CH2 C6 H5 , CH2 CH2 (4-F)C6 H4 ) to their corresponding radical cations is achieved with mildly oxidizing ferrocenium ion. Cyclovoltammetric studies reveal ground-state redox potentials of up to -1.90 V vs. Fc+/0 for such oxy-borylenes placing them among the strongest organic super electron donors. Their ability as photoreductants is further supported by theoretical studies and showcased by the application as stoichiometric reagents for the photochemical hydrodehalogenation of aryl chlorides, aryl bromides and unactivated alkyl bromides as well as the detosylation of anilines.

Unsaturated amido-substituted six-vertex mixed silicon germanium clusters.

The synthesis of mixed silicon and germanium clusters SixGe6-x{N(SiMe3)Dipp}41-3 (x = 3.7, 3.1, 2.1) with amido-substituents and two unsubstituted germanium atoms was achieved in co-reductions using the tribromosilane {N(SiMe3)Dipp}SiBr3 and the tribromogermane {N(SiMe3)Dipp}GeBr3 in three different ratios. The ratio of Si and Ge used for the synthesis of 1-3 approximately corresponds to that in the final products. All compounds were characterized by single crystal X-ray diffraction and EI mass spectrometry. In addition, 1 and 2 were characterized by solid-state 29Si{1H} CP/MAS NMR spectroscopy and multinuclear NMR spectroscopy in solution.

Advanced Dual-Ion Batteries with High-Capacity Negative Electrodes Incorporating Black Phosphorus.

Dual-graphite batteries (DGBs), being an all-graphite-electrode variation of dual-ion batteries (DIBs), have attracted great attention in recent years as a possible low-cost technology for stationary energy storage due to the utilization of inexpensive graphite as a positive electrode (cathode) material. However, DGBs suffer from a low specific energy limited by the capacity of both electrode materials. In this work, a composite of black phosphorus with carbon (BP-C) is introduced as negative electrode (anode) material for DIB full-cells for the first time. The electrochemical behavior of the graphite || BP-C DIB cells is then discussed in the context of DGBs and DIBs using alloying anodes. Mechanistic studies confirm the staging behavior for anion storage in the graphite positive electrode and the formation of lithiated phosphorus alloys in the negative electrode. BP-C containing full-cells demonstrate promising electrochemical performance with specific energies of up to 319 Wh kg-1 (related to masses of both electrode active materials) or 155 Wh kg-1 (related to masses of electrode active materials and active salt), and high Coulombic efficiency. This work provides highly relevant insights for the development of advanced high-energy and safe DIBs incorporating BP-C and other high-capacity alloying materials in their anodes.