Boosting Sodium Compensation Efficiency via a CNT/MnO2 Catalyst toward High-Performance Na-Ion Batteries.

The formation of a solid electrolyte interphase on carbon anodes causes irreversible loss of Na+ ions, significantly compromising the energy density of Na-ion full cells. Sodium compensation additives can effectively address the irreversible sodium loss but suffer from high decomposition voltage induced by low electrochemical activity. Herein, we propose a universal electrocatalytic sodium compensation strategy by introducing a carbon nanotube (CNT)/MnO2 catalyst to realize full utilization of sodium compensation additives at a much-reduced decomposition voltage. The well-organized CNT/MnO2 composite with high catalytic activity, good electronic conductivity, and abundant reaction sites enables sodium compensation additives to decompose at significantly reduced voltages (from 4.40 to 3.90 V vs Na+/Na for sodium oxalate, 3.88 V for sodium carbonate, and even 3.80 V for sodium citrate). As a result, sodium oxalate as the optimal additive achieves a specific capacity of 394 mAh g-1, almost reaching its theoretical capacity in the first charge, increasing the energy density of the Na-ion full cell from 111 to 158 Wh kg-1 with improved cycle stability and rate capability. This work offers a valuable approach to enhance sodium compensation efficiency, promising high-performance energy storage devices in the future.

Quantum enhanced radio detection and ranging with solid spins.

The accurate radio frequency (RF) ranging and localizing of objects has benefited the researches including autonomous driving, the Internet of Things, and manufacturing. Quantum receivers have been proposed to detect the radio signal with ability that can outperform conventional measurement. As one of the most promising candidates, solid spin shows superior robustness, high spatial resolution and miniaturization. However, challenges arise from the moderate response to a high frequency RF signal. Here, by exploiting the coherent interaction between quantum sensor and RF field, we demonstrate quantum enhanced radio detection and ranging. The RF magnetic sensitivity is improved by three orders to 21 [Formula: see text], based on nanoscale quantum sensing and RF focusing. Further enhancing the response of spins to the target's position through multi-photon excitation, a ranging accuracy of 16 µm is realized with a GHz RF signal. The results pave the way for exploring quantum enhanced radar and communications with solid spins.

A Randomized, Double-Blind, Controlled Trial of Percutaneous Tibial Nerve Stimulation With Pelvic Floor Exercises in the Treatment of Childhood Constipation.

INTRODUCTION: The management of childhood constipation is challenging. Pelvic floor dysfunction (PFD) is one of the most common causes of childhood constipation. Percutaneous tibial nerve stimulation (PTNS) with pelvic floor exercises (PFE) has achieved a satisfactory outcome in the elderly individuals and women with PFD. The efficacy of PTNS with PFE in childhood constipation has not been established. METHODS: A randomized, double-blind, controlled trial with 84 children who met the inclusion criteria was conducted. All participants were randomly assigned to PTNS with PFE or sham PTNS with PFE groups and received their individual intervention for 4 weeks with a 12-week follow-up evaluation. The spontaneous bowel movements (SBM) ≥3 per week were the main outcomes, and the risk ratio (RR) with 95% confidence interval (CI) were calculated. High-resolution anorectal manometry and surface electromyography were used for the assessment of pelvic floor function, and the adverse effects were assessed based on symptoms. RESULTS: At the end of the follow-up period, 26 patients (61.9%) in the PTNS with PFE group and 15 patients (35.7%) in the sham group had ≥3 SBM per week compared with baseline (net difference 26.2%, 95% CI 5.6%-46.8%; RR 2.750, 95% CI 1.384-5.466; P < 0.05). PFD remission occurred in 49 children, 33 (78.6%) in the PTNS with PFE group and 16 (38.1%) in the sham group (RR 2.063, 95% CI 1.360-3.128, P < 0.05). No adverse effects occurred. DISCUSSION: PTNS with PFE is a safe and effective method in the treatment of childhood constipation, particularly in children with PFD or dyssynergic defecation.

[Upper gastrointestinal ulcer in children: a clinical analysis of 173 cases]. / 儿童上消化道溃疡173例临床分析.

OBJECTIVES: To study the clinical manifestations and gastroscopic characteristics of upper gastrointestinal ulcer in children. METHODS: A retrospective analysis was performed for the children who underwent gastroscopy and were found to have upper gastrointestinal ulcer for the first time at the Endoscopy Center of Shengjing Hospital, China Medical University, from January 2011 to May 2021. According to the cause of the disease, they were divided into primary ulcer group (primary group; n=148) and secondary ulcer group (secondary group; n=25). The clinical data were compared between the two groups. RESULTS: A total of 173 children with upper gastrointestinal ulcer were enrolled, with a male/female ratio of 3.9:1. Compared with girls, boys had significantly higher proportions of duodenal ulcer and primary ulcer (P<0.05). Compared with the children aged below 6 years, the children aged 6-14 years had higher proportions of duodenal ulcer and primary ulcer and lower proportions of giant ulcer and multiple ulcers. Of the 148 children in the primary group, 95 (64.2%) had Helicobacter pylori infection. Abdominal pain was the most common clinical symptom and was observed in 101 children (68.2%). Duodenal ulcer was common and was observed in 115 children (77.7%), followed by gastric ulcer in 25 children (16.9%) and esophageal ulcer in 7 children (4.7%). Multiple ulcers were observed in 32 children (21.6%). Seventy children (47.3%) experienced complications, among which bleeding was the most common complication and was observed in 63 children (43.6%). Of the 25 children in the secondary group, abdominal pain was the most common clinical symptom and was observed in 9 children (36.0%), with a significantly lower incidence rate than the primary group (P<0.05); foreign body in the digestive tract was the most common cause of ulcer and was observed in 17 children (68%), followed by abdominal Henoch-Schönlein purpura in 5 children (20.0%) and Crohn's disease in 3 children (12.0%). The secondary group had a significantly higher proportion of multiple ulcer or giant ulcer than the primary group (P<0.05). CONCLUSIONS: Upper gastrointestinal ulcer is more common in boys than girls, and duodenal ulcer and primary ulcer are more common in boys. Children aged 6-14 years often have duodenal ulcer and primary ulcer, and giant ulcer and multiple ulcers are relatively uncommon. Primary ulcer in children has a variety of clinical manifestations, mainly abdominal pain, and duodenal ulcer is relatively common, with bleeding as the main complication. The clinical symptoms and endoscopic manifestations of secondary ulcer are closely associated with the primary causes, and it is more likely to induce huge ulcers and multiple ulcers.

Layered Oxide Cathode-Electrolyte Interface towards Na-Ion Batteries: Advances and Perspectives.

With the ever increasing demand for low-cost and economic sustainable energy storage, Na-ion batteries have received much attention for the application on large-scale energy storage for electric grids because of the worldwide distribution and natural abundance of sodium element, low solvation energy of Na+ ion in the electrolyte and the low cost of Al as current collectors. Starting from a brief comparison with Li-ion batteries, this review summarizes the current understanding of layered oxide cathode/electrolyte interphase in NIBs, and discusses the related degradation mechanisms, such as surface reconstruction and transition metal dissolution. Recent advances in constructing stable cathode electrolyte interface (CEI) on layered oxide cathode are systematically summarized, including surface modification of layered oxide cathode materials and formulation of electrolyte. Urgent challenges are detailed in order to provide insight into the imminent developments of NIBs.

Focusing the electromagnetic field to 10-6λ for ultra-high enhancement of field-matter interaction.

Focusing electromagnetic field to enhance the interaction with matter has been promoting researches and applications of nano electronics and photonics. Usually, the evanescent-wave coupling is adopted in various nano structures and materials to confine the electromagnetic field into a subwavelength space. Here, based on the direct coupling with confined electron oscillations in a nanowire, we demonstrate a tight localization of microwave field down to 10-6λ. A hybrid nanowire-bowtie antenna is further designed to focus the free-space microwave to this deep-subwavelength space. Detected by the nitrogen vacancy center in diamond, the field intensity and microwave-spin interaction strength are enhanced by 2.0 × 108 and 1.4 × 104 times, respectively. Such a high concentration of microwave field will further promote integrated quantum information processing, sensing and microwave photonics in a nanoscale system.

P3/O3 Integrated Layered Oxide as High-Power and Long-Life Cathode toward Na-Ion Batteries.

Low-cost and stable sodium-layered oxides (such as P2- and O3-phases) are suggested as highly promising cathode materials for Na-ion batteries (NIBs). Biphasic hybridization, mainly involving P2/O3 and P2/P3 biphases, is typically used to boost their electrochemical performances. Herein, a P3/O3 intergrown layered oxide (Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 ) as high-rate and long-life cathode for NIBs via tuning the amounts of Ti substitution in Na2/3 Ni1/3 Mn2/3- x Tix O2 (x = 0, 1/6, 1/3, 2/3) is demonstrated. The X-ray diffraction (XRD) Rietveld refinement and aberration-corrected scanning transmission electron microscopy show the co-existence of P3 and O3 phases, and density functional theory calculation corroborates the appearance of the anomalous O3 phase at the Ti substitution amount of 1/3. The P3/O3 biphasic cathode delivers an unexpected rate capability (≈88.7% of the initial capacity at a high rate of 5 C) and cycling stability (≈68.7% capacity retention after 2000 cycles at 1 C), superior to those of the sing phases P3-Na2/3 Ni1/3 Mn2/3 O2 , P3-Na2/3 Ni1/3 Mn1/2 Ti1/6 O2 , and O3-Na2/3 Ni1/3 Ti2/3 O2 . The highly reversible structural evolution of the P3/O3 integrated cathode observed by ex situ XRD, ex situ X-ray absorption spectra, and the rapid Na+ diffusion kinetics, underpin the enhancement. These results show the important role of P3/O3 biphasic hybridization in designing and engineering layered oxide cathodes for NIBs.

Large-Scale Synthesis of the Stable Co-Free Layered Oxide Cathode by the Synergetic Contribution of Multielement Chemical Substitution for Practical Sodium-Ion Battery.

The O3-type layered oxide cathodes for sodium-ion batteries (SIBs) are considered as one of the most promising systems to fully meet the requirement for future practical application. However, fatal issues in several respects such as poor air stability, irreversible complex multiphase evolution, inferior cycling lifespan, and poor industrial feasibility are restricting their commercialization development. Here, a stable Co-free O3-type NaNi0.4Cu0.05Mg0.05Mn0.4Ti0.1O2 cathode material with large-scale production could solve these problems for practical SIBs. Owing to the synergetic contribution of the multielement chemical substitution strategy, this novel cathode not only shows excellent air stability and thermal stability as well as a simple phase-transition process but also delivers outstanding battery performance in half-cell and full-cell systems. Meanwhile, various advanced characterization techniques are utilized to accurately decipher the crystalline formation process, atomic arrangement, structural evolution, and inherent effect mechanisms. Surprisingly, apart from restraining the unfavorable multiphase transformation and enhancing air stability, the accurate multielement chemical substitution engineering also shows a pinning effect to alleviate the lattice strains for the high structural reversibility and enlarges the interlayer spacing reasonably to enhance Na+ diffusion, resulting in excellent comprehensive performance. Overall, this study explores the fundamental scientific understandings of multielement chemical substitution strategy and opens up a new field for increasing the practicality to commercialization.

Stimulated emission assisted time-gated detection of a solid-state spin.

The nitrogen vacancy (NV) center in diamond is studied widely for magnetic field and temperature sensing at the nanoscale. Usually, the fluorescence is recorded to estimate the spin state of the NV center. Here we applied a time-gating technique to improve the contrast of the spin-dependent fluorescence. A NIR pulsed laser pumped the stimulated emission of the NV center and depleted the spontaneous emission that was excited by a green laser. We changed the relative delay between the NIR laser and the green laser. Then the spontaneous emission of the NV center in varied time windows was extracted by comparing the fluorescence intensities with and without the NIR laser. The results showed that the spin-dependent fluorescence contrast could be improved by approximately 1.8 times by applying the time gating. The background of the environment was eliminated due to temporal filtering. This work demonstrates that the stimulated emission assisted time-gating technique can be used to improve the performance of an NV center sensor in a noisy environment.

Iron Porphyrin Catalyzed Insertion Reaction of N-Tosylhydrazone-Derived Carbenes into X-H (X = Si, Sn, Ge) Bonds.

An efficient Fe(TPP)Cl catalyzed insertion reaction of in situ generated benzylic carbenes from N-tosylhydrazones into X-H (X = Si, Sn, Ge) was developed. Silanes bearing tertiary, secondary, and primary (3°, 2°, and 1°) Si-H bonds all reacted well to afford insertion products in moderate to high yields (up to 97%), and the reaction time could be significantly shortened to 1 h under microwave irradiation. A programmable stepwise double insertion strategy was developed for the synthesis of unsymmetrical tetrasubstituted silanes.

Cu2+ Dual-Doped Layer-Tunnel Hybrid Na0.6Mn1- xCu xO2 as a Cathode of Sodium-Ion Battery with Enhanced Structure Stability, Electrochemical Property, and Air Stability.

Sodium-ion batteries (SIBs) have been regarded as a promising candidate for large-scale renewable energy storage system. Layered manganese oxide cathode possesses the advantages of high energy density, low cost and natural abundance while suffering from limited cycling life and poor rate capacity. To overcome these weaknesses, layer-tunnel hybrid material was developed and served as the cathode of SIB, which integrated high capacity, superior cycle ability, and rate performance. In the current work, the doping of copper was adopted to suppress the Jahn-Teller effect of Mn3+ and to affect relevant structural parameters. Multifunctions of the Cu2+ doping were carefully investigated. It was found that the structure component ratio is varied with the Cu2+ doping amount. Results demonstrated that Na+/vacancy rearrangement and phase transitions were suppressed during cycling without sacrificing the reversible capacity and enhanced electrochemical performances evidenced with 96 mA h g-1 retained after 250 cycles at 4 C and 85 mA h g-1 at 8 C. Furthermore, ex situ X-ray diffraction has demonstrated high reversibility of the Na0.6Mn0.9Cu0.1O2 cathode during Na+ extraction/insertion processes and superior air stability that results in better storage properties. This study reveals that the Cu2+ doping could be an effective strategy to tune the properties and related performances of Mn-based layer-tunnel hybrid cathode.

[Expression of MMP-2 in the periodontal tissues with the mini-screw for molar intrusion with cyclic intrusive force in dogs].

PURPOSE: To observe the expression of MMP-2 in the periodontal tissues of molars in Beagle dogs after different times of intrusion by mini-screw with cyclic intrusive force. METHODS: Three mature Beagle dogs were used for the experiment. On the buccal and palatal sites of the left maxillary second and third premolars, a minis-crew was placed at the inter-radicular septa separately, intruding the tooth with 150 g initial force, which would be reinforced every 4 weeks. The teeth of left side as the experimental group were divided into 3 subgroups, as being intruded 12, 24 and 36 weeks, and the right side as blank control. Then the dogs were sacrificed, and the second and the third premolars with the surrounding periodontal tissue were cut down, fixed, decalcified, wrapped and cut into slices. Immunohistochemical staining with MMP-2 was performed. The average optical density (OD) of MMP-2 was calculated with IPP software, which represented the expression of MMP-2. SPSS 17.0 software package was used for statistical analysis. RESULTS: Immunohistochemical staining revealed that the expression of MMP-2 in control group was low. After tooth intrusion, MMP-2 expression significantly increased in the periodontal tissues of molars, and reached the maximum in the group of 24 weeks. Then MMP-2 expression decreased in the 36-week group but still significantly higher than the control group. There was no significant difference among the 3 subgroups for different intrusion times(P>0.05). CONCLUSIONS: MMP-2 participates in remodeling of the periodontal tissue during tooth intrusion. The expression of MMP-2 is not significantly increased with the extension of the intrusion time with cyclic intrusive force, which suggests that with the use of mini-screw to intrude the molars with cyclic intrusive force, the periodontal tissues of the intruded tooth maintain dynamic balance of bone remodeling.