Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries.

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries; however, its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion batteries. The present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials, explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials, and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based materials. This review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials, with particular focuses on their molecular, crystalline, and aggregation structures. Furthermore, the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization analyses. Finally, future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

The comparison of fluidized positioners and traditional gel pads for skin protection in neurosurgical patients undergoing lateral and prone positions: A retrospective analysis with propensity score matching method.

To compare fluidized positioners and gel pads for skin protection in neurosurgery patients placed in lateral and prone positions. It is one of the major challenges that operating room nurses face in protecting the skin during the long duration of neurosurgery. Currently, there are increasing tools available to protect the skin under pressure, and various tools practice well in the clinic. Fluidized positioners are newly emerging protective pads that have been clinically effective in protecting the skin, but no studies have compared them to previous pads. This is a retrospective cohort study. Data from 706 patients who underwent neurosurgery between January 2018 and December 2021 were systemically reviewed. Patients undergoing long-term neurosurgery in the neurosurgical lateral and prone positions were divided into two groups: fluidized positioners or gel pads. Propensity score matching (PSM) was performed for group balance (1:1 ratio) using the following baseline characteristics: age, gender, ASA (American Society of Anesthesiologists) classification, duration of surgery, surgical position and underlying disease. The incidence of decubitus, and length of stay (LOS) in the hospital were compared between the two groups. The results were obtained for 394 patients in the fluidized positioner group with a 3.8% incidence of pressure ulcers and 312 patients in the gel pad group with an 8% incidence of pressure ulcers, which were unbalanced in terms of gender, ASA, hypertension and diabetes data. After a PSM, patients were compared in terms of pressure ulcer incidence (3.7% vs. 7.8%, p = 0.034) and LOS (22.35 vs. 25.65 days, p < 0.001). Fluidized positioners can effectively reduce the incidence of pressure injury in lateral and prone positions of neurosurgery. The results of this study may contribute to the development of policies to prevent the development of pressure ulcers during neurosurgical procedures.

Woven fabric-based separators with low tortuosity for sodium-ion batteries.

In order to achieve high-performance and stable sodium-ion batteries, numerous attempts have been made to construct continuous ion transport pathways, in which a separator is one of the key components that affects the battery performance. In this study, a novel low-tortuosity woven fabric separator is fabricated by combining a weaving technique with a cellulose-solution method, followed by an infusion of a TEMPO-oxidized bacterial cellulose slurry into woven fabric substrates. The macropores in the fabric combine with the micropores in the oxidized bacterial cellulose to form a separator with a suitable pore structure and low tortuosity, forming a continuous sodium ion transport channel within the sodium-ion battery and effectively enhancing ion transport dynamics. The results show that, compared with a commercial polypropylene separator, the TEMPO-oxidized bacterial cellulose-woven fabric separator has a special weaving structure and lower tortuosity (0.77), as well as significant advantages in tensile strength (3.07 MPa), ionic conductivity (1.15 mS c), ionic transfer number (0.75), thermal stability, and electrochemical stability. This novel and simple preparation method provides new possibilities for achieving high-performance separators of sodium-ion batteries through rational structural design by textile technology.

Application of quantitative analysis for aluminum alloy in femtosecond laser-ablation spark-induced breakdown spectroscopy using one-point and multi-line calibration.

To achieve the quantitative elemental analysis of aluminum alloy samples, the one-point and multi-line calibration (OP-MLC) method and femtosecond laser-ablation spark-induced breakdown spectroscopy (fs-LA-SIBS) were combined in this study. An ultrafast Ti: sapphire laser with high single-pulse energy and high repetition-rate operation was used as the laser source to ablate the sample at a 1k Hz pulse repetition rate and achieve re-excitation using spark discharge. Subsequently, an enhanced spectral peak intensity was achieved, which increased the sensitivity and analytical capabilities of laser-induced breakdown spectroscopy (LIBS) technique. Considering only one confirmed sample, the OP-MLC method was used to calculate the concentration ratios of trace elements Mg, Cr, Cu, Mn and Zn in four aluminum alloy samples to the calibration samples by the integral intensity ratio of the elemental characteristic lines between the two samples. The average relative errors with the identified concentrations were 3.99%, 15.13%, 8.76%, 9.30% and 9.64%, respectively. The results showed that the combination of OP-MLC method and fs-LA-SIBS has good accuracy in the quantitative analysis of elements, and has the advantages of simplicity, rapidity and high sensitivity.

Bacterial cellulose-derived micro/mesoporous carbon anode materials controlled by poly(methyl methacrylate) for fast sodium ion transport.

An advanced nanostructure with rational micro/mesoporous distribution plays an important role in achieving high electrochemical performance in sodium ion batteries (SIBs), especially the energy storage efficiency in the low-potential region during the charging/discharging processes. Here we propose a method of polymer-blended bacterial cellulose (BC) matrix to tune the micro/mesopores of polymer-BC derived carbon under a mild carbonization temperature. The targeted pore structure and electrochemical performance are optimized by controlling the amount of methyl methacrylate monomers via free-radical polymerization, and carbonized temperature via pyrolysis treatment. The constructed carbon materials display a stable 3D fibrous network with a large specific area and abundant micro/mesopores formed during the pyrolysis of the polymer poly(methyl methacrylate) (PMMA). Taking advantage of the constructed pore structure, the optimized carbon anodes derived from BC/PMMA composites show an enhanced Na+ diffusion rate with a high capacity of 380.66 mA h g-1 at 0.03 A g-1. It is interesting that it possesses superior low-potential capacity, and retains 42% of the total capacity even at a high scan rate of 1 mV s-1. The proposed method of polymer-blended on cellulose matrix provides an energy-efficient way to achieve high low-potential capacity under facile processing conditions for fast sodium ion transport in SIBs.

Ultrasonic-assisted synthesis of two dimensional BiOCl/MoS2 with tunable band gap and fast charge separation for enhanced photocatalytic performance under visible light.

Janus shaped BiOCl/MoS2 composites with two dimensional configuration are successfully prepared via a facile pulse ultrasonic assisted method, which spontaneously introduces oxygen vacancies on the BiOCl surface and builds well-defined heterojuction at the BiOCl/MoS2 interfaces. The as-prepared BiOCl/MoS2 composites possess reduced band gap and defect energy levels due to the incorporation of MoS2 and the oxygen vacancies, which permits the enhanced light harvesting efficiency in the visible range. In addition, because of the formed BiS bonds at the BiOCl/MoS2 interface, the composites demonstrate improved charge separation of the photo-generated carriers. Therefore, when used as photocatalyst for Rhodamine B photodegradation, the optimized composite demonstrates a degradation rate of 0.078 min-1, which is much enhanced compared with that of pure BiOCl (0.052 min-1). Mechanism investigation indicates the degradation is a hole mediated process. In addition, the composite shows good stability and outstanding organic carbon removal efficiency, which could serve as a promising photocatalyst for water remediation under visible light.

In-situ synthesis of molybdenum sulfide/reduced graphene oxide porous film as robust counter electrode for dye-sensitized solar cells.

Molybdenum sulfide/reduced graphene oxide (MoS2/RGO) porous film was in-situ deposited on fluorine-doped tin oxide (FTO) substrates via a one-pot hydrothermal method. Due to the oxygen-containing groups distributing on graphene oxide (GO) surface, the MoS2 sheets could nucleate and grow taking GO as substrates and the MoS2/RGO film can be strongly linked to the FTO. Based on the electrochemical investigations, the enhanced cell performance could be ascribed to the improved electrical conductivity, catalytic active sites and electrolyte diffusion rate, which finally contribute to the high catalytic performance on the reduction of I-/I3- couples in the electrolyte. Therefore, the cell adopting as-prepared MoS2/RGO as counter electrode demonstrated high power conversion efficiencies (PCE) of 7.63%, which indicates ∼14% enhancement compared with the MoS2-based (6.68%) device.

[Elemental Analysis of Alloys with Picosecond Dual-Pulse LA-LIBS under Low Sample Destruction].

A study on elemental analysis of alloy samples under low sample destruction with dual-pulse laser-ablation laser induced breakdown spectroscopy (LA-LIBS) based on one picosecond Nd : YAG laser is presented. In LA-LIBS, low pulse energy 532 nm laser was used for sample ablation and high pulse energy, time­delayed 1 064 nm laser was used for re-excitation of the ablated samples to enhance atomic emissions of the laser-induced plasma and signal detection sensitivity. The influence of pulse energies of the ablation laser and excitation laser to the signal intensities was studied experimentally. I was observed that Cu 324.75 nm line intensity in LA-LIBS was enhanced 86 times in comparison with that obtained in SP-LIBS under 10 µJ pulse energy of the ablation laser and 2.5 mJ pulse energy of the excitation laser. The diameter of the crater generated in LA-LIBS was less than 10 µm. It is demonstrated the possibility of using dual-pulse LA-LIBS to realize elemental analysis of solid sample under low sample destruction. This technique is valuable for elemental analysis of precious samples and 2D elements mapping under high spatial resolution.

Plasmon resonance energy transfer and hot electron injection induced high photocurrent density in liquid junction Ag@Ag2S sensitized solar cells.

An in situ technique was developed to deposit Ag@Ag2S core-shell quantum dots on a SnO2 mesoporous film for solar energy conversion. When adopted as a photoanode, an impressive high photocurrent density of ∼25.6 mA cm-2 was demonstrated in a cell configuration using polysulfide S2-/Sn2- as an electrolyte and Cu2S/brass as a counter electrode, which leads to a power conversion efficiency of ∼0.784% for this environmentally benign device. Optical measurements showed that Ag nanoparticles could be employed as plasmon resonance centers to enhance the harvesting efficiency of incident light at the visible and near-infrared range. Moreover, photoluminescence spectra demonstrated fast charge transfer at Ag@Ag2S/SnO2 interfaces, which facilitates direct hot electron injection from sensitizers to the SnO2 matrix and finally gives rise to the high photocurrent density.

Controlled light field concentration through turbid biological membrane for phototherapy.

Laser propagation through a turbid rat dura mater membrane is shown to be controllable with a wavefront modulation technique. The scattered light field can be refocused into a target area behind the rat dura mater membrane with a 110 times intensity enhancement using a spatial light modulator. The efficient laser intensity concentration system is demonstrated to imitate the phototherapy for human brain tumors. The power density in the target area is enhanced more than 200 times compared with the input power density on the dura mater membrane, thus allowing continued irradiation concentration to the deep lesion without damage to the dura mater. Multibeam inputs along different directions, or at different positions, can be guided to focus to the same spot behind the membrane, hence providing a similar gamma knife function in optical spectral range. Moreover, both the polarization and the phase of the input field can be recovered in the target area, allowing coherent field superposition in comparison with the linear intensity superposition for the gamma knife.

Tunable synthesis of single-crystalline-like TiO2 mesocrystals and their application as effective scattering layer in dye-sensitized solar cells.

Single-crystalline-like TiO2 mesocrystals (TMCs) with spherical and spindle-like shapes were selectively prepared in acetic acid system using benzoic acid as structural directing regent. It was found that the intermediate butyl-benzoic acid could interval the oriented assembly of the primary nanoparticles as porogen and shape regulator, which results in spherical TMCs with greater pore size distribution compared with the spindle-like TMCs. When used as scattering layer in dye sensitized solar cells (DSSCs), the spherical TMCs with long-range ordered stacking pattern results in characteristic photonic reflection, which enhances the scattering effect of the photoanode and leads to a high short circuit current density of 16.6 mA cm(-2). Therefore, Cell-spherical TMCs demonstrated a high power conversion efficiencies of 8.10%, indicating substantial improvements compared with Cell-spindle-like TMCs (7.58%) and Cell-nanoparticle (6.59%).

Analysis of epidermal growth factor signaling in nasal mucosa epithelial cell proliferation involved in chronic rhinosinusitis.

BACKGROUND: Aberrant epithelial repair has been observed in chronic rhinosinusitis (CRS) patients; however, the mechanism of epithelial cell repair regulation is unclear. Epidermal growth factor (EGF) plays an important role in regulating epithelial cell repair in lower airway and may be a critical factor in the remodeling processes of CRS. The objective of our research is to evaluate the differences between CRS and normal subjects and between chronic rhinosinusitis without nasal polys (CRSsNP) and chronic rhinosinusitis with nasal polys (CRSwNP) in the regulation of EGF pathways and the regulating proliferative position of classic Ras/Raf/MEK/ERK pathways. METHODS: We evaluated the proliferation rates of ethmoidal mucosal cells before and after stimulation with EGF, epidermal growth factor receptor (EGFR) kinase inhibitor AG1478, and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 using MTT assays. We also analyzed the sinonasal epithelial cells collected from control subjects and patients with CRS subtypes CRSsNP and CRSwNP for the expression of ERK1/2, phosphorylated ERK1/2, P21, P15, and P27 using western blotting analyses. RESULTS: The proliferation rates of sinonasal epithelial cells before and after EGF stimulation were lower in CRS patients than in the controls. AG1478 or PD98059 inhibitor treatment of control epithelial cells did not result in a significant difference in proliferation. Although, AG1478 and PD98059 inhibited the proliferation of CRS cells, the degree of proliferation inhibition was markedly different in CRSsNP. AG1478 suppressed the proliferation of CRSwNP epithelial cells, whereas PD98059 had no effect. The ratio of ERK1/2 phosphorylation in CRS cells was lower than that of the control cells. Cyclin-dependent kinase inhibitors were highly expressed in CRS cells compared with that of control cells. ERK1/2 and P27 showed differential expression in CRSsNP and CRSwNP. CONCLUSIONS: Differences existed in EGF pathways in CRS patients and normal subjects as well as in CRSsNP and CRSwNP. Classical Ras/Raf/MEK/ERK pathway may assume absolute superiority in control cells. Ras/Raf/MEK/ERK classical pathway and other pathways might be active at the same time to stimulate epithelial cell proliferation in CRSsNP. The function of Ras/Raf/MEK/ERK classical pathway was weaker in CRSwNP than in CRSsNP and when the classical pathway was blocked in CRSwNP, some other pathway could have completely compensated the proliferation induced by the Ras/Raf/MEK/ERK pathway.