A lightweight bladder tumor segmentation method based on attention mechanism.

In the endoscopic images of bladder, accurate segmentation of different grade bladder tumor from blurred boundary regions and highly variable shapes is of great significance for doctors' diagnosis and patients' later treatment. We propose a nested attentional feature fusion segmentation network (NAFF-Net) based on the encoder-decoder structure formed by the combination of weighted pyramid pooling module (WPPM) and nested attentional feature fusion (NAFF). Among them, WPPM applies the cascade of atrous convolution to enhance the overall perceptual field while introducing adaptive weights to optimize multi-scale feature extraction, NAFF integrates deep semantic information into shallow feature maps, effectively focusing on edge and detail information in bladder tumor images. Additionally, a weighted mixed loss function is constructed to alleviate the impact of imbalance between positive and negative sample distribution on segmentation accuracy. Experiments illustrate the proposed NAFF-Net achieves better segmentation results compared to other mainstream models, with a MIoU of 84.05%, MPrecision of 91.52%, MRecall of 90.81%, and F1-score of 91.16%, and also achieves good results on the public datasets Kvasir-SEG and CVC-ClinicDB. Compared to other models, NAFF-Net has a smaller number of parameters, which is a significant advantage in model deployment.

In Situ Constructing Ultrastable Mechanical Integrity of Single-Crystalline LiNi0.9 Co0.05 Mn0.05 O2 Cathode by Interior and Exterior Decoration Strategy.

Planar gliding along with anisotropic lattice strain of single-crystalline nickel-rich cathodes (SCNRC) at highly delithiated states will induce severe delamination cracking that seriously deteriorates LIBs' cyclability. To address these issues, a novel lattice-matched MgTiO3 (MTO) layer, which exhibits same lattice structure as Ni-rich cathodes, is rationally constructed on single-crystalline LiNi0.9 Co0.05 Mn0.05 O2 (SC90) for ultrastable mechanical integrity. Intensive in/ex situ characterizations combined with theoretical calculations and finite element analysis suggest that the uniform MTO coating layer prevents direct contact between SC90 and organic electrolytes and enables rapid Li-ion diffusion with depressed Li-deficiency, thereby stabilizing the interfacial structure and accommodating the mechanical stress of SC90. More importantly, a superstructure is simultaneously formed in SC90, which can effectively alleviate the anisotropic lattice changes and decrease cation mobility during successive high-voltage de/intercalation processes. Therefore, the as-acquired MTO-modified SC90 cathode displays desirable capacity retention and high-voltage stability. When paired with commercial graphite anodes, the pouch-type cells with the MTO-modified SC90 can deliver a high capacity of 175.2 mAh g-1 with 89.8% capacity retention after 500 cycles. This lattice-matching coating strategy demonstrate a highly effective pathway to maintain the structural and interfacial stability in electrode materials, which can be a pioneering breakthrough in commercialization of Ni-rich cathodes.

Electrochemical selective lithium extraction and regeneration of spent lithium iron phosphate.

In this paper, a green, efficient and low-cost process for the selective recovery of lithium from spent LiFePO4 by anodic electrolysis is proposed. The leaching rates of Li, Fe and P under different conditions were explored and the optimal conditions are obtained. In the optimal conditions, Li, Fe and P leaching rates were 96.31%, 0.06% and 0.62% respectively. The Li/Fe selectivity was over 99.9%. The product obtained is isostructural FePO4 and retains the original particle morphology. The FePO4 obtained can be synthesised into LiFePO4/C by direct regeneration process or impurity removal regeneration process. The material synthesized by the latter process has a better electrochemical performance, with a discharge specific capacity of 144.5 mAh/g at 1.0C and a capacity retention of 92.0% over 500cycles. The superior performance can be attributed to an impurity removal process that reduced agglomeration and improved particle morphology.

Accurate measurement and enhancement of fiber coil symmetry.

The pure Shupe effect is substantially reduced in a fiber optic gyroscope (FOG) with symmetrical windings. However, the effect of the temperature-induced nonuniformity of the stress in the coil depends on the mean temperature derivative (T-dot). Research on precision winding technology has discovered that the symmetry of optical fiber rings affects the temperature performance of fiber optic gyroscopes. Optical fiber rings with good symmetry also have good temperature performance. This paper first establishes a temperature drift model of optical fiber rings that includes the Shupe effect and T-dot effect and then uses finite element simulation to analyze the drift error of optical fiber rings in a variable temperature environment. Analysis shows that this drift is caused by the variation and uneven distribution of the fiber length and the refractive index in the positive and negative winding of the optical fiber ring, which results in a residual phase difference that is directly related to the symmetry of the optical fiber ring. Simulation and analysis show that balancing the residual phase difference of the optical fiber ring can be achieved by cutting the length of the optical fiber ring at both ends. This paper uses optical frequency domain reflectometry (OFDR) technology to precisely test the symmetry of the optical fiber ring, ensuring accurate adjustment of the lengths at both ends of the optical fiber ring. Experimental tests on two gyroscopes have shown that the optical fiber ring with a smaller drift error can be obtained after testing and adjusting its length. The experimental data indicates that the bias stability of two laboratory gyros are increased by 23.6% and 18.1%, and the bias range are reduced by 22.4% and 30.0%.

Enhanced mechanical strength of a highly de-lithiated single-crystal Ni-rich cathode to suppress irreversible planar gliding.

The mechanical properties of de-lithiated single-crystal Ni-rich cathodes are causing extensive concern. Here, we first show that the compression hardness of single crystal Ni-rich cathode particles decreases significantly at highly de-lithiated states by micro-compression testing. Thus, phase-boundary hardening was introduced to inhibit the planar gliding, resulting in excellent electrochemical performance.

Double-Layer Electrolyte Boosts Cycling Stability of All-Solid-State Li Metal Batteries.

All-solid-state lithium metal batteries (ASSLMBs), as a candidate for advanced energy storage devices, invite an abundance of interest due to the merits of high specific energy density and eminent safety. Nevertheless, issues of overwhelming lithium dendrite growth and poor interfacial contact still limit the practical application of ASSLMBs. Herein, we designed and fabricated a double-layer composite solid electrolyte (CSE), namely, PVDF-LiTFSI-Li1.3Al0.3Ti1.7(PO4)3/PVDF-LiTFSI-h-BN (denoted as PLLB), for ASSLMBs. The reduction-tolerant PVDF-LiTFSI-h-BN (denoted as PLB) layer of the CSE tightly contacts with the Li metal anode to avoid the reduction of LATP by the electrode and participates in the formation of a stable SEI film using Li3N. Meanwhile, the oxidation-resistance and ion-conductive PVDF-LiTFSI- LATP (denoted as PLA) layer facing the cathode can reduce the interfacial impedance by facilitating ionic migration. With the synergistic effect of PLA and PLB, the Li/Li symmetric cells with sandwich-type electrolytes (PLB/PLA/PLB) can operate for 1500 h with ultralong cycling stability at 0.1 mA cm-2. Additionally, the LiFePO4/Li cell with PLLB maintains satisfactory capacity retention of 88.2% after 250 cycles. This novel double-layer electrolyte offers an effective approach to achieving fully commercialized ASSLMBs.

Construction of Planar Gliding Restriction Buffer and Kinetic Self-Accelerator Stabilizing Single-Crystalline LiNi0.9Co0.05Mn0.05O2 Cathode.

The single-crystalline Ni-rich cathode has aroused much attention for extenuating the cycling and safety crises in comparison to the polycrystalline cathode. However, planar gliding and kinetic hindrance hinder its chemo-mechanical properties with cycling, which induce delamination cracking and damage the mechanical integrity in single crystals. Herein, a robust Li2.64(Sc0.9Ti0.1)2(PO4)3 (LSTP) ion/electron conductive network was constructed to decorate single-crystal LiNi0.9Co0.05Mn0.05O2 (SC90) particles. Via physicochemical characterizations and theoretical calculations, this LSTP coating that evenly grows on the SC90 particle with good lattice matching and strong bonding effectively restricts the anisotropic lattice collapse along the c-axis and the cation mixing activity of SC90, thus suppressing planar gliding and delamination cracking during repeated high-voltage lithiation/delithiation processes. Moreover, such a 3D LSTP network can also facilitate the lithium-ion transport and prevent the electrolyte's corrosion, lightening the kinetic hindrance and triggering the surface phase transformation. Combined with the Li metal anode, the LSTP-modified SC90 cell exhibits a desirable capacity retention of 90.5% at 5 C after 300 cycles and stabilizes the operation at 4.3/4.5 V. Our results provide surface modification engineering to mitigate planar gliding and kinetic hindrance of the single-crystalline ultra-high Ni-rich cathode, which inspires peers to design other layered cathode materials.

Study of Synergistic Effects of Cu and Fe on P2-Type Na0.67MnO2 for High Performance Na-Ion Batteries.

P2-type Na0.67MnO2 with a stable structure and an open framework can provide numerous channels for fast Na+ de/intercalation, for which it is considered to be advantageous in application of the cathode material for Na-ion batteries. However, the complex phase transition occurring during cycling and the lattice distortion triggered by the Jahn-Teller effect severely restrict its development. Herein, the modified Na0.67MnO2 with Cu or Fe single-element doping as well as Cu and Fe double-element doping was synthesized by the sol-gel method, and the effects of doping on the crystal structure and electrochemical performances of Na0.67MnO2 were studied. It was demonstrated that the phase of the material did not change after the introduction of Cu and Fe elements, and the cycling stability and rate performance were greatly improved by Cu and Fe double-doping owing to their synergistic effect. The Na0.67Mn0.92Fe0.04Cu0.04O2 (NMFCO) cathode delivers discharge specific capacities of 110.5 mA h g-1 at 5 C and 91.8 mA h g-1 at 10 C and exhibits the high-capacity retention of 94.35% at 1 C and 90.68% at 5 C after 100 cycles. Overall, this study offers a guiding direction for accelerating the modification of P2-type Na0.67MnO2 as a cathode active material for high performance Na-ion batteries.

Transthoracic minimally invasive closure for the treatment of ruptured sinus of Valsalva aneurysm: immediate and mid-term follow-up results.

BACKGROUND: We aimed to evaluate the immediate and mid-term outcomes of transthoracic minimally invasive closure (TMIC) of ruptured sinus of Valsalva aneurysm (RSVA), which is a rare and mostly congenital heart disease. METHODS: From January 2014 to November 2020, 19 patients (16 males, 3 females) with RSVA were selected for TMIC and were followed up at our centre. Data were analysed from our prospectively collected database and clinical mid-term follow-up was obtained. RESULTS: Among these 19 cases, transthoracic echocardiography showed rupture of the right coronary sinus to the right atrium in 9 patients, non-coronary sinus rupture to the right atrium in 7 patients, and right coronary sinus rupture to the right ventricle in 3 patients. Most (13/19) cases were New York Heart Association (NYHA) functional class III or IV. The mean diameters of the defect from the aortic end and ruptured site were 8.8±3.0 and 6.4±2.6 mm, respectively. TMIC was attempted using ventricular septal defect (VSD)/patent ductus arteriosus (PDA) occluders 2-7 mm larger than the aortic ends of the defects. All patients were successfully treated by TMIC and achieved complete closure at discharge after a mean hospital stay length of 6.2±2.5 days. Seventeen patients were NYHA class I while 2 patients were NYHA class II. No cases of residual shunts, device embolization, infective endocarditis, or aortic regurgitation were observed during a median follow-up of 36 months (range, 16-84 months). CONCLUSIONS: In appropriately selected cases with RSVA, TMIC is an attractive alternative to surgery, with a high technical success rate and encouraging short-term and mid-term outcomes. However, long-term follow-up is needed.

The LORF5 Gene Is Non-essential for Replication but Important for Duck Plague Virus Cell-to-Cell Spread Efficiently in Host Cells.

Duck plague virus (DPV) can cause high morbidity and mortality in many waterfowl species within the order Anseriformes. The DPV genome contains 78 open reading frames (ORFs), among which the LORF2, LORF3, LORF4, LORF5, and SORF3 genes are unique genes of avian herpesvirus. In this study, to investigate the role of this unique LORF5 gene in DPV proliferation, we generated a recombinant virus that lacks the LORF5 gene by a two-step red recombination system, which cloned the DPV Chinese virulent strain (DPV CHv) genome into a bacterial artificial chromosome (DPV CHv-BAC); the proliferation law of LORF5-deleted mutant virus on DEF cells and the effect of LORF5 gene on the life cycle stages of DPV compared with the parent strain were tested. Our data revealed that the LORF5 gene contributes to the cell-to-cell transmission of DPV but is not relevant to virus invasion, replication, assembly, and release formation. Taken together, this study sheds light on the role of the avian herpesvirus-specific gene LORF5 in the DPV proliferation life cycle. These findings lay the foundation for in-depth functional studies of the LORF5 gene in DPV or other avian herpesviruses.

Multifunctionality of cerium decoration in enhancing the cycling stability and rate capability of a nickel-rich layered oxide cathode.

The structural collapse and surface chemical degradation of nickel-rich layered oxide cathodes (NCM) of lithium-ion batteries during operation, which result in severe capacity attenuation, are the major challenges that hinder their commercial development. To improve the cycle and rate performances of LiNi0.8Co0.1Mn0.1O2 (NCM811), in this study, we have constructed a double-shell structure protective layer with a surface CeO2-x coating and interfacial spinel-like phase, which mitigate particle microcrack formation and isolate the NCM811 particles from electrolyte erosion. Additionally, during heat-treatment calcination, tetravalent cerium ions with strong oxidation ability can be partially doped into the material, which causes partial oxidation of Ni2+ to Ni3+, thereby reducing the Li+/Ni2+ mixing. The strong Ce-O bonds formed in the lattice help to improve the stability of the structure in the highly de-lithiated state. Thus, the synergy of multifunctional cerium modification effectively improves the structural stability and electrochemical kinetics of the material during cycling. Impressively, the obtained Ce-NCM811 exhibits capacity retention of 80.3% at a high discharge rate of 8 C after 500 cycles, which is much higher than that of the pristine cathode (only 44.3%). This work successfully designed a material with multi-functional Ce modification to provide a basis for Ni-rich cathode materials, which is crucial as it effectively improves the electrochemical performance.

Enhancing Cell Performance of Lithium-Rich Manganese-Based Materials via Tailoring Crystalline States of a Coating Layer.

Li-rich Mn-based-layered oxides are considered to be the most felicitous cathode material candidates for commercial application of lithium-ion batteries on account of high energy density. Nevertheless, defects containing an unsatisfactory initial Coulombic efficiency and rapid voltage decay seriously impede their practical utilization. Herein, a coating layer with three distinct crystalline states are employed as a coating layer to modify Li[Li0.2Mn0.54Ni0.13Co0.13]O2, respectively, and the effects of coating layers with distinct crystalline states on the crystal structure, diffusion kinetics, and cell performance of host materials are further explored. A coating layer with high crystallinity enables mitigatory voltage decay and better cyclic stability of materials, while a coating layer with planar defects facilitates Li+ transfer and enhances the rate performance of materials. Consequently, optimizing the crystalline state of coating substances is critical for preferable surface modification.

Encouraging Voltage Stability upon Long Cycling of Li-Rich Mn-Based Cathode Materials by Ta-Mo Dual Doping.

The Li-rich and Mn-based material xLi2MnO3·(1-x)LiMO2 (M = Ni, Co, and Mn) is regarded as one of the new generations of cathode materials for Li-ion batteries due to its high energy density, low cost, and less toxicity. However, there still exist some drawbacks such as its high initial irreversible capacity, capacity/voltage fading, poor rate capability, and so forth, which seriously limit its large-scale commercial applications. In this paper, the Ta-Mo codoped Li1.2Ni0.13Co0.13Mn0.54O2 with high energy density is prepared via a coprecipitation method, followed by a solid-state reaction. The synthetic mechanism and technology, the effect of charge-discharge methods, the bulk doping and the surface structure design on the structure, morphology, and electrochemical performances of the Li1.2Ni0.13Co0.13Mn0.54O2 cathode are systematically investigated. The results show that Ta5+ and Mo6+ mainly occupy the Li site and transition-metal site, respectively. Both the appropriate Ta and Ta-Mo doping are conductive to increase the Mn3+ concentration and suppress the generation of Li/Ni mixing and the oxygen defects. The Ta-Mo codoped cathode sample can deliver 243.2 mA h·g-1 at 1 C under 2.0-4.8 V, retaining 80% capacity retention after 240 cycles, and decay 1.584 mV per cycle in 250 cycles. The capacity retention can be still maintained to 80% after 410 cycles over 2.0-4.4 V, and the average voltage fading rate is 0.714 mV per cycle in 500 cycles. Compared with the pristine, the capacity and voltage fading of Ta-Mo codoped materials are effectively suppressed, which are mainly ascribed to the fact that the highly valence Ta5+ and Mo6+ that entered into the crystal lattice are favorable for maintaining the charge balance, and the strong bond energies of Ta-O and Mo-O can help to maintain the crystal structure and relieve the corrosion from the electrolyte during the charging/discharging process.

Ultra-Thin AlPO4 Layer Coated LiNi0.7Co0.15Mn0.15O2 Cathodes With Enhanced High-Voltage and High-Temperature Performance for Lithium-Ion Half/Full Batteries.

Side-reactions in LiNi1-x-yCo x Mn y O2 (0≤- x+y≤1) cathode materials are one kind of the problems that would deteriorate the surface structure and the electrochemical stabilities of the cathodes, especially when they are working at high cut-off voltages and high temperatures. In this study, an ultrathin (~10 nm) AlPO4 coating layer was fabricated through a two-step "feeding" process on LiNi0.7Co0.15Mn0.15O2 (NCM) cathode materials. The structure and chemical composition of the AlPO4 coating were studied by XRD, SEM, TEM, and XPS characterizations. Further electrochemical testing revealed that the AlPO4-coated LiNi0.7Co0.15Mn0.15O2 cathode exhibited enhanced electrochemical stabilities in the case of high cut-off voltage at both 25 and 55°C. In detail, the AlPO4-coated LiNi0.7Co0.15Mn0.15O2 could deliver 186.50 mAh g-1 with 81.5% capacity retention after 100 cycles at 1C over 3-4.5 V in coin cell, far higher than the 71.4% capacity retention of the pristine electrode. In prismatic full cell, the coated sample also kept 89.5% capacity retention at 25°C and 81.1% capacity retention at 55°C even after 300 cycles (2.75-4.35 V, 1C), showing better cycling stability than that of the pristine NCM. The ultrathin AlPO4 coating could not only keep the bulk structure stability from the surface degradation, but also diminishes the electrochemical resistance varies after cycles, thereby supporting the coated cathodes with enhanced electrochemical stability.

Self-assembled GeOX/Ti3C2TX Composites as Promising Anode Materials for Lithium Ion Batteries.

High-capacity germanium-based anode materials are alternative materials for outstanding electrochemical performance lithium-ion batteries (LIBs), but severe volume variation and pulverization problems during charging-discharging processes can seriously affect their electrochemical performance. In addressing this challenge, a simple strategy was used to prepare the self-assembled GeOX/Ti3C2TX composite in which the GeOX nanoparticles can grow directly on Ti3C2TX layers. Nanoscale GeOX uniformly renucleates on the surface and interlayers of Ti3C2TX, forming the stable multiphase structure, which guarantees its excellent electrochemical performance. Electrochemical evaluation has shown that the rate capability and reversibility of GeOX/Ti3C2TX are both greatly improved, which delivers a reversible discharge specific capacity of above 1400 mAh g-1 (at 100 mA g-1) and a reversible specific capacity of 900 mAh g-1 after 50 cycles while it still maintains a stable specific capacity of 725 mAh g-1 at 5000 mA g-1. Furthermore, the composite exhibits an exceptionally superior rate capability, making it a good electrochemical performance anode for LIBs.

In Situ-Formed Hollow Cobalt Sulfide Wrapped by Reduced Graphene Oxide as an Anode for High-Performance Lithium-Ion Batteries.

Transition-metal sulfides have been considered as promising anode materials for lithium-ion batteries (LIBs) due to their high theoretical specific capacity and superior electrochemical performance. However, the large volume change during the discharge/charge process causes structural pulverization, resulting in rapid capacity decline and the loss of active materials. Herein, we report Co1-xS hollow spheres formed by in situ growth on reduced graphene oxide layers. When evaluated as an anode material for LIBs, it delivers a specific capacity of 969.8 mAh·g-1 with a high Coulombic efficiency of 96.49% after 90 cycles. Furthermore, a high reversible capacity of 527.2 mAh·g-1 after the 107th cycle at a current density of 2.5 A g-1 is still achieved. The results illustrate that in situ growth on the graphene layers can enhance conductivity and restrain volume expansion of cobalt sulfide compared with ex situ growth.

Synthesis of a fine LiNi0.88Co0.09Al0.03O2 cathode material for lithium-ion batteries via a solvothermal route and its improved high-temperature cyclic performance.

Nickel-Cobalt-Aluminum (NCA) cathode materials for lithium-ion batteries (LIBs) are conventionally synthesized by chemical co-precipitation. However, the co-precipitation of Ni2+, Co2+, and Al3+ is difficult to control because the three ions have different solubility product constants. This study proposes a new synthetic route of NCA, which allows fabrication of fine and well-constructed NCA cathode materials by a high temperature solid-state reaction assisted by a fast solvothermal process. The capacity of the LiNi0.88Co0.09Al0.03O2 as-synthesized by the solvothermal method was 154.6 mA h g-1 at 55 °C after 100 cycles, corresponding to 75.93% retention. In comparison, NCA prepared by the co-precipitation method delivered only 130.3 mA h g-1 after 100 cycles, with a retention of 63.31%. Therefore, the fast solvothermal process-assisted high temperature solid-state method is a promising candidate for synthesizing high-performance NCA cathode materials.

Influence of the Synthesis Route on the Properties of Hybrid NiO-MnCo2 O4 -Ni6 MnO8 Anode Materials and their Electrochemical Performances.

New materials with different morphologies, nanostructures, and components can have structural advantages for application in materials science. Multicomponent-active hybrid nanostructured materials are among the best candidates for application in electrode materials. Spray pyrolysis and solvothermal synthesis are two popular methods for the preparation of multicomponent-active hybrid nanostructured materials. In this study, the two types of NiO-MnCo2 O4 -Ni6 MnO8 hybrid anode materials for use in lithium-ion batteries were synthesized by two different methods (spray pyrolysis and solvothermal synthesis), and the differences in their physical and electrochemical properties were compared. The two types of anode material exhibited the same hierarchical hybrid composition, but some different physical characteristics, which affected their electrochemical performance.

Boosting Cell Performance of LiNi0.8 Co0.15 Al0.05 O2 via Surface Structure Design.

Although the high energy density and environmental benignancy of LiNi0.8 Co0.15 Al0.05 O2 (NCA) holds promise for use as cathode material in Li-ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode (R-3m) with 5 nm-thick nanopillar layers and Fm-3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge-discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni-rich layered cathode materials.

[Regulation effects of reverse-slope level terrace on the runoff and sediment yield in sloping farmland].

A dynamic monitoring on the rainfall-runoff process and the surface runoff and sediment yield in a sloping farmland was conducted at a natural rainfall runoff plot in the watershed of Jianshan River, the first tributary of Fuxian Lake, Chengjiang, aimed to study the regulation effects of reverse-slope level terrace on the runoff and sediment yield in red soil sloping farmlands of Yunnan. The regulation rates of runoff and sediment yield by the reverse-slope level terrace were 49.5%-87.7% and 56.7%-96.1%, averagely 65.3% and 80.7%, respectively, showing that the regulation effects of reverse-slope level terrace on the runoff and sediment yield, especially the latter in sloping farmland were prominent. The variation coefficients of the test parameters for undisturbed sloping farmland and reverse-slope level terrace were in the order of sediment yield > runoff > rainfall. Comparing with undisturbed sloping farmland, reverse-slope level terrace had smaller surface runoff and smaller relative deviation degree of sediment yield, demonstrating its remarkable effect in controlling runoff and sediment yield in sloping farmland.