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High-performance and temperature-resistant lithium-ion batteries (LIBs), which are able to operate at elevated temperatures (i.e., >60 °C) are highly demanded in various fields, especially in military or aerospace exploration. However, their applications were largely impeded by the poor electrochemical performance and unsatisfying safety issues, which were induced by the severe side reactions between electrolytes and electrodes at high temperatures. Herein, with the synergetic effects of solvation chemistry and functional additive in the elaborately designed weakly solvating electrolyte, a unique robust organic/inorganic hetero-interphase, composed of gradient F, B-rich inorganic components and homogeneously distributed Si-rich organic components, was successfully constructed on both cathodes and anodes, which would effectively inhibit the constant decomposition of electrolytes and dissolution of transition metal ions, thus highly enhancing the high-temperature electrochemical performance. As a result, both cathodes and anodes, without compromising their low-temperature performance, can operate at temperatures ≥100 °C, with excellent capacity retentions of 96.1 % after 500 cycles and 93.5 % after ≥200 cycles, respectively, at 80 °C. Ah-level LiCoO2||graphite full cells with a cut-off voltage of 4.3â V also exhibited superior temperature-resistance with a capacity retention of 89.9 % at temperature as high as 120 °C. Moreover, the fully charged pouch cells exhibited highly enhanced safety, demonstrating their potentials in practical applications at ultrahigh temperatures.
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A novel functional additive model is proposed, which is uniquely modified and constrained to model nonlinear interactions between a treatment indicator and a potentially large number of functional and/or scalar pretreatment covariates. The primary motivation for this approach is to optimize individualized treatment rules based on data from a randomized clinical trial. We generalize functional additive regression models by incorporating treatment-specific components into additive effect components. A structural constraint is imposed on the treatment-specific components in order to provide a class of additive models with main effects and interaction effects that are orthogonal to each other. If primary interest is in the interaction between treatment and the covariates, as is generally the case when optimizing individualized treatment rules, we can thereby circumvent the need to estimate the main effects of the covariates, obviating the need to specify their form and thus avoiding the issue of model misspecification. The methods are illustrated with data from a depression clinical trial with electroencephalogram functional data as patients' pretreatment covariates.
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Modelos Estatísticos , Medicina de Precisão , Ensaios Clínicos Controlados Aleatórios como Assunto , HumanosRESUMO
Recent years have seen an explosion of activity in the field of functional data analysis (FDA), in which curves, spectra, images, etc. are considered as basic functional data units. A central problem in FDA is how to fit regression models with scalar responses and functional data points as predictors. We review some of the main approaches to this problem, categorizing the basic model types as linear, nonlinear and nonparametric. We discuss publicly available software packages, and illustrate some of the procedures by application to a functional magnetic resonance imaging dataset.
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This study aimed to determine whether the addition of butyric acid glycerides as substitutes to conventional growth promoters can provide adequate zootechnical performance and intestinal health in healthy piglets in the nursery phase. We used 90 male piglets (average weight of 6.5 kg) subdivided into five treatments with six replicates per treatment. The treatments had the same basal diet: NC-negative control (without growth promoter), PC-positive control (with gentamicin, oral), PSB-protected sodium butyrate, FSB-free sodium butyrate, and TRI-tributyrin. In these animals, zootechnical performance was evaluated on days 1, 10, 20 and 39, microbiological analysis on days 14 and 39, hematocrit, blood biochemistry and intestinal histology, intestinal oxidation and antioxidation on day 39. The average daily weight gain was higher in the TRI group on days 21 to 39 in the nursery (P = 0.03), with more significant weight gain from 1 to 39 days (P = 0.05). There were higher leukocyte counts in the PC group than in the TRI group and higher lymphocyte counts in the PC treatment than in the NC or TRI groups. Escherichia coli counts were lower in the PC, followed by the PSB and TRI groups on day 39 (P = 0.01). Lower crypt depths were found in the TRI and FSB groups, followed by PC, than in the NC group (P = 0.01). Higher values for crypt villosity ratio were found in the FSB and TRI groups than in the NC group (P = 0.05). Lower lipid peroxidation was found in analyzes of serum oxidative status (LPO: P = 0.01), associated with greater activities of superoxide dismutase - SOD (P = 0.08), glutathione S-transferase - GST (P = 0.09) in PSB and TRI groups than in the NC group. In conclusion, the use of butyric acid in the form of tributyrin can be used as growth enhancers in piglets in the nursery phase.
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Antibacterianos , Glicerídeos , Suínos , Animais , Masculino , Ácido Butírico/farmacologia , Antibacterianos/farmacologia , Dieta/veterinária , Aumento de Peso , Escherichia coli , Ração Animal/análiseRESUMO
High nickel (Ni ≥ 80%) lithium-ion batteries (LIBs) with high specific energy are one of the most important technical routes to resolve the growing endurance anxieties. However, because of their extremely aggressive chemistries, high-Ni (Ni ≥ 80%) LIBs suffer from poor cycle life and safety performance, which hinder their large-scale commercial applications. Among varied strategies, electrolyte engineering is very powerful to simultaneously enhance the cycle life and safety of high-Ni (Ni ≥ 80%) LIBs. In this review, the pivotal challenges faced by high-Ni oxide cathodes and conventional LiPF6 -carbonate-based electrolytes are comprehensively summarized. Then, the functional additives design guidelines for LiPF6 -carbonate -based electrolytes and the design principles of high voltage resistance/high safety novel electrolytes are systematically elaborated to resolve these pivotal challenges. Moreover, the proposed thermal runaway mechanisms of high-Ni (Ni ≥ 80%) LIBs are also reviewed to provide useful perspectives for the design of high-safety electrolytes. Finally, the potential research directions of electrolyte engineering toward high-performance high-Ni (Ni ≥ 80%) LIBs are provided. This review will have an important impact on electrolyte innovation as well as the commercial evolution of high-Ni (Ni ≥ 80%) LIBs, and also will be significant to breakthrough the energy density ceiling of LIBs.
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Organic acids (OAs) are a class of feed additives that have prophylactic and inhibitory properties against pathogenic bacteria. In this study, we investigated growth performance, innate immune response, gut microbiota, and disease resistance against Francisella orientalis F1 in Nile tilapia (Oreochromis niloticus) fed different doses of Bacti-nil®Aqua, a blend of short- and medium-chain OAs. For 21 days, 680 juvenile tilapias were fed a control diet or diets supplemented with a 0.3% (D3) or 0.5% (D5) OA blend. The feed conversion rate of fish fed the 0.5% enriched diet was considerably lower (p < 0.05) than that of the fish fed the basal diet. Lysozyme and serum bactericidal activities were significantly elevated following OA administration. After infection, no differences in the diversity and composition of gut microbiota were observed between the groups. After the bacterial challenge, the mortality was significantly lower in group D5 (p < 0.01). The diet supplemented with Bacti-nil®Aqua (Adisseo) improved the immune response and resistance of tilapia juveniles against F. orientalis infection. Thus, this OA blend could serve as a feed additive with good activity against F. orientalis.
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Ciclídeos , Doenças dos Peixes , Microbioma Gastrointestinal , Infecções Estreptocócicas , Animais , Ração Animal/análise , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/veterinária , Suplementos Nutricionais/análise , Imunidade Inata , Dieta/veterinária , Resistência à DoençaRESUMO
Halloysite nanotubes (HNTs) are naturally occurring nanomaterials with a tubular shape and high aspect ratio, a promising functional additive for active food packaging applications. HNTs have been shown to possess unique properties such as high surface area, thermal stability, and biocompatibility, making them attractive for active food packaging materials. This review summarizes recent research on the use of HNTs as functional additives in active food packaging applications, including antimicrobial packaging, ethylene scavenging packaging, moisture, and gas barrier packaging. The potential benefits and challenges associated with the incorporation of HNTs into food packaging materials are discussed. The various modification methods, such as the physical, chemical, biological, and electrostatic methods, along with their impact on the properties of HNTs, are discussed. The advantages and challenges associated with each modification approach are also evaluated. Overall, the modification of HNTs has opened new possibilities for the development of advanced packaging materials with improved performance for various functional food packaging materials with enhanced properties and extended shelf life.
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Although their cost-effectiveness and intrinsic safety, aqueous zinc-ion batteries suffer from notorious side reactions including hydrogen evolution reaction, Zn corrosion and passivation, and Zn dendrite formation on the anode. Despite numerous strategies to alleviate these side reactions have been demonstrated, they can only provide limited performance improvement from a single aspect. Herein, a triple-functional additive with trace amounts, ammonium hydroxide, was demonstrated to comprehensively protect zinc anodes. The results show that the shift of electrolyte pH from 4.1 to 5.2 lowers the HER potential and encourages the in situ formation of a uniform ZHS-based solid electrolyte interphase on Zn anodes. Moreover, cationic NH4+ can preferentially adsorb on the Zn anode surface to shield the "tip effect" and homogenize the electric field. Benefitting from this comprehensive protection, dendrite-free Zn deposition and highly reversible Zn plating/stripping behaviors were realized. Besides, improved electrochemical performances can also be achieved in Zn//MnO2 full cells by taking the advantages of this triple-functional additive. This work provides a new strategy for stabilizing Zn anodes from a comprehensive perspective.
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The efficiency loss and stability issues of perovskite devices mainly derive from nonradiative recombination, caused by detrimental defects in the perovskite bulk and at the interface between the perovskite absorber and charge transport layer. Therefore, the passivation of these defects is of great concern in achieving high-performance perovskite devices. Here, we report the incorporation of potassium phenyl trifluoroborate (KC6H5BF3) into perovskite films to realize simultaneous passivation of the grain boundaries and the perovskite/SnO2 interface. Apart from the bulk passivation of K+, the accumulation of C6H5BF3- at the buried interface contributes to the compact contact between the perovskite absorber and SnO2 layer and also the perfect columnar perovskite grains. As a result, the KC6H5BF3-containing perovskite films exhibit low trap density. The distinct enhancements of open-circuit voltage and photoelectric conversion efficiency are obtained together with negligible hysteresis. The open-circuit voltage of the KC6H5BF3-containing device increases from 1.09 to 1.18 V, and the corresponding efficiency increases from 19.69 to 22.33%. The finding in this work shows the superiority of the dual-functional additive for preparing highly efficient perovskite devices.
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The individual moiety-functionalized organosilane single molecule, that is, 1,1,1,5,5,5-hexamethyl-3-[(trimethylsilyl)oxy]-3-vinyltrisiloxane (TMSV), is investigated as an electrolyte additive for a less charge-consuming and viscoelastic solid electrolyte interphase (SEI) forming agent, finally accomplishing extremely quick (6 min) rechargeable SiO/NCM811 lithium-ion batteries. The moiety of the vinyl group serves with a poly(ethylene oxide)-like viscoelastic SEI film on the SiO electrode, which provides a physicochemically stable interphase during long-term cycling. The increase of DC-iR due to electrolyte decomposition on the continuously exposed SiO surface with cycling is inhibited by the alternated SEI composition. Degradation of bulk electrolyte solution caused by thermal decomposition of the LiPF6 salt is also suppressed by the trimethylsilyl moiety in the TMSV additive, which scavenges HF. Owing to the multifunctionality of TMSV, the cycle performance of laminated pouch full cells comprising high-nickel-contented NCM811 positive electrode and SiO-enriched negative electrode is significantly improved at both room and elevated temperatures. Furthermore, the 6 min quick recharging cycle performance is also enhanced by the TMSV additive.
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Li metal thickness has been considered a key factor in determining the electrochemical performance of Li metal anodes. The use of thin Li metal anodes is a prerequisite for increasing the energy density of Li secondary batteries intended for emerging large-scale electrical applications, such as electric vehicles and energy storage systems. To utilize thin (20 µm thick) Li metal anodes in Li metal secondary batteries, we investigated the synergistic effect of a functional additive (Li nitrate, LiNO3) and a dual-salt electrolyte (DSE) system composed of Li bis(fluorosulfonyl)imide (LiTFSI) and Li bis(oxalate)borate (LiBOB). By controlling the amount of LiNO3 in DSE, we found that DSE containing 0.05 M LiNO3 (DSE-0.05 M LiNO3) significantly improved the electrochemical performance of Li metal anodes. DSE-0.05 M LiNO3 increased the cycling performance by 146.3% [under the conditions of a 1C rate (2.0 mA cm-2), DSE alone maintained 80% of the initial discharge capacity up to the 205th cycle, whereas DSE-0.05 M LiNO3 maintained 80% up to the 300th cycle] and increased the rate capability by 128.2% compared with DSE alone [the rate capability of DSE-0.05 M LiNO3 = 50.4 mAh g-1, and DSE = 39.3 mAh g-1 under 7C rate conditions (14.0 mA cm-2)]. After analyzing the Li metal surface using scanning electron microscopy and X-ray photoelectron spectroscopy, we were able to infer that the stabilized solid electrolyte interphase layer formed by the combination of LiNO3 and the dual salt resulted in a uniform Li deposition during repeated Li plating/stripping processes.
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Thermal stabilizers, lubricant, and plasticizers are three crucial additives for processing poly(vinyl chloride) (PVC). In this study, a new mannitol stearate ester-based aluminum alkoxide (MSE-Al) was designed and synthesized as a novel additive for PVC. The thermal stability and processing performance of PVC stabilized by MSE-Al were evaluated by the Congo red test, conductivity measurement, thermal aging test, ultravioletevisible (UV-Vis) spectroscopy test, and torque rheometer test. Results showed that the addition of MSE-Al could not only markedly improve the long-term thermal stability of PVC, but also greatly accelerate the plasticizing and decrease the balance torque, which demonstrated that MSE-Al possessed a lubricating property. Thus, MSE-Al was demonstrated to be able to provide tri-functional additive roles, e.g., thermal stabilizer, plasticizer, and lubricant. The test results for the thermal stability of PVC indicated that the initial whiteness of PVC stabilized by MSE-Al was not good enough, thus the synergistic effect of MSE-Al with zinc stearates (ZnSt2) on the thermal stability of PVC was also investigated. The results showed that there is an appreciable synergistic effect between MSE-Al and ZnSt2. The thermal stabilization mechanism and synergism effect of MSE-Al with ZnSt2 are then discussed.
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Surface properties of cast films of poly(lactic acid) (PLA) containing 1 wt% of several glycolipid-type biosurfactants (BSs) were investigated. The wettability of PLA films containing a homologue of mannosylerythritol lipids (MEL-B), lactone-form sophorolipid (LSL), or cellobiose lipid (CL) was drastically higher than that of untreated PLA and several synthetic surfactants-containing PLA. Surface wettability was also dependent on the hydrophilicity of the substrate used during solvent casting of the PLA films. The wetting behavior of the opposing sides of MEL-B-containing films prepared on glass substrates differed significantly; the contact angle on the side of the film that had been in contact with the glass surface was significantly lower than that obtained on the side of the film that had been in contact with air. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis results showed that the MEL in MEL-B-containing thin PLA cast films was localized to a thin surface layer. These results suggest self-assembly of MEL-B and micro-phase separation between the PLA matrix and MEL-B domains. This resulted in the localization and orientation of MEL-B at the surface of the cast PLA film, which determined its specific wetting behavior.
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Glicolipídeos/química , Plásticos/química , Poliésteres/química , Tensoativos/química , Interações Hidrofóbicas e Hidrofílicas , MolhabilidadeRESUMO
Highly reductive magnesium borohydride [Mg(BH4)2] is compatible with metallic Mg, making it a promising Mg-ion electrolyte for rechargeable Mg batteries. However, pure Mg(BH4)2 in ether-based solutions displays very limited solubility (0.01 M), low oxidative stability (<1.8 V vs Mg), and nucleophilic characteristic, all of which preclude its practical utilization for any battery applications. Herein, we present a multifunctional additive of tris(2 H-hexafluoroisopropyl)borate (THFPB) for preparing Mg(BH4)2-based electrolytes. By virtue of the strong electron-acceptor ability of the THFPB molecule, a transparent and high-concentration Mg(BH4)2/THFPB-diglyme (DGM) electrolyte (0.5 M, almost 50 times higher than that of the pristine Mg(BH4)2-DGM electrolyte) is first obtained, which shows dramatic performance improvements, including high ionic conductivity (3.72 mS cm-1 at 25 °C) and high Mg plating/stripping Coulombic efficiency (>99%). The newly-generated active cation and anion species revealed by Raman, NMR and MS spectra, increase the electrochemical potential window from 1.8 V to 2.8 V vs Mg on stainless steel electrode, rendering electrolytes the ability to examine high voltage cathodes. More importantly, on account of the non-nucleophilicity of active electrolyte species, we present the first example of magnesium-sulfur (Mg-S) batteries using Mg(BH4)2-based electrolytes, which exhibit a high discharge capacity of 955.9 and 526.5 mA h g-1 at the initial and 30th charge/discharge cycles, respectively. These achievements not only provide an efficient and specific strategy to eliminate the major roadblocks facing Mg(BH4)2-based electrolytes but also highlight the profound effect of functional additives on the electrochemical performances of unsatisfied Mg-ion electrolytes.
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Trapping lithium polysulfides formed in the sulfur positive electrode of lithium-sulfur batteries is one of the promising approaches to overcome the issues related to polysulfide dissolution. In this work, we demonstrate that intrinsically hydrophilic magnesium oxide (MgO) nanoparticles having surface hydroxyl groups can be used as effective additives to trap lithium polysulfides in the positive electrode. MgO nanoparticles were uniformly distributed on the surface of the active sulfur, and the addition of MgO into the sulfur electrode resulted in an increase in capacity retention of the lithium-sulfur cell compared to a cell with pristine sulfur electrode. The improvement in cycling stability was attributed to the strong chemical interactions between MgO and lithium polysulfide species, which suppressed the shuttling effect of lithium polysulfides and enhanced the utilization of the sulfur active material. To the best of our knowledge, this report is the first demonstration of MgO as an effective functional additive to trap lithium polysulfides in lithium-sulfur cells.