Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nano Lett ; 24(14): 4165-4171, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38534019

RESUMO

An electrical-controllable antiferromagnet tunnel junction is a key goal in spintronics, holding immense promise for ultradense and ultrastable antiferromagnetic memory with high processing speed for modern information technology. Here, we have advanced toward this goal by achieving an electrical-controllable antiferromagnet-based tunnel junction of Pt/Co/Pt/Co/IrMn/MgO/Pt. The exchange coupling between antiferromagnetic IrMn and Co/Pt perpendicular magnetic multilayers results in the formation of an interfacial exchange bias and exchange spring in IrMn. Encoding information states "0" and "1" is realized through the exchange spring in IrMn, which can be electrically written by spin-orbit torque switching with high cyclability and electrically read by antiferromagnetic tunneling anisotropic magnetoresistance. Combining spin-orbit torque switching of both exchange spring and exchange bias, a 16 Boolean logic operation is successfully demonstrated. With both memory and logic functionalities integrated into our electrically controllable antiferromagnetic-based tunnel junction, we chart the course toward high-performance antiferromagnetic logic-in-memory.

2.
Curr Issues Mol Biol ; 46(2): 1047-1063, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38392184

RESUMO

Due to the extensive genetic and antigenic variation in Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), as well as its rapid mutability and evolution, PRRS prevention and control can be challenging. An expeditious and sensitive neutralization assay for PRRSV is presented to monitor neutralizing antibodies (NAbs) in serum during vaccine research. Here, a PRRSV expressing eGFP was successfully rescued with reverse genetics based on the infectious clone HuN4-F112-eGFP which we constructed. The fluorescent protein expressions of the reporter viruses remained stable for at least five passages. Based on this reporter virus, the neutralization assay can be easily used to evaluate the level of NAbs by counting cells with green fluorescence. Compared with the classical CPE assay, the newly developed assay increases sensitivity by one- to four-fold at the early antibody response stage, thus saving 2 days of assay waiting time. By using this assay to unveil the dynamics of neutralizing antibodies against PRRSV, priming immunity through either a single virulent challenge or only vaccination could produce limited NAbs, but re-infection with PRRSV would induce a faster and stronger NAb response. Overall, the novel HuN4-F112-eGFP-based neutralization assay holds the potential to provide a highly efficient platform for evaluating the next generation of PRRS vaccines.

3.
Small ; 20(2): e2305481, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37658518

RESUMO

This work reports a dual heterojunction of etched MIL-68(In)-NH2 (MN) supported heptazine-/triazine-based carbon nitride (HTCN) via a facile hydrothermal process for photocatalytic ammonia (NH3 ) synthesis. By applying the hydrothermal treatment, MN microrods are chemically etched into hollow microtubes, and HTCN with nanorod array structures are simultaneously tightly anchored on the outside surface of the microtubes. With the addition of 9 wt% HTCN, the resulting dual heterojunction presents an enhanced photocatalytic ammonia yield rate of 5.57 mm gcat -1 h-1 with an apparent quantum efficiency of 10.89% at 420 nm. Moreover, stable ammonia generation using seawater, tap water, lake water, and turbid water in the absence of sacrificial reagents verifies the potential of the dual-heterojunction composites as a commercially viable photosystem. The obtained one-dimensional (1D) microtubes and coating of HTCN confers this unique composite with extended visible-light harvesting and accelerated charge carrier migration via a multi-stepwise charge transfer pathway. This work provides a new strategy for optimizing nitrogen (N2 )-into-ammonia conversion efficiency by designing novel dual-heterojunction catalysts.

4.
Small ; : e2402219, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634337

RESUMO

In this work, an intramolecular carbon nitride (CN)-based quaternary homojunction functionalized with pyridine rings is prepared via an in situ alkali-assisted copolymerization strategy of bulk CN and 2-aminopyridine for efficient visible light hydrogen generation. In the obtained structure, triazine-based CN (TCN), heptazine-based CN (HCN), pyridine unit incorporated TCN, and pyridine ring inserted HCN constitute a special multicomponent system and form a built-in electric field between the crystalline semiconductors by the arrangement of energy band levels. The electron-withdrawing function of the conjugated heterocycle can trigger the skeleton delocalization and edge induction effect. Highly accelerated photoelectron-hole transfer rates via multi-stepwise charge migration pathways are achieved by the synergistic effect of the functional group modification and molecular quaternary homojunction. Under the addition of 5 mg 2-aminopyridine, the resulting homojunction framework exhibits a significantly improved hydrogen evolution rate of 6.64 mmol g-1 h-1 with an apparent quantum efficiency of 12.27% at 420 nm. Further, the catalyst verifies its potential commercial value since it can produce hydrogen from various real water environments. This study provides a reliable way for the rational design and fabrication of intramolecular multi-homojunction to obtain high-efficient photocatalytic reactions.

5.
Small ; : e2402432, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850181

RESUMO

This paper presents a scalable and straightforward technique for the immediate patterning of liquid metal/polymer composites via multiphase 3D printing. Capitalizing on the polymer's capacity to confine liquid metal (LM) into diverse patterns. The interplay between distinctive fluidic properties of liquid metal and its self-passivating oxide layer within an oxidative environment ensures a resilient interface with the polymer matrix. This study introduces an inventive approach for achieving versatile patterns in eutectic gallium indium (EGaIn), a gallium alloy. The efficacy of pattern formation hinges on nozzle's design and internal geometry, which govern multiphase interaction. The interplay between EGaIn and polymer within the nozzle channels, regulated by variables such as traverse speed and material flow pressure, leads to periodic patterns. These patterns, when encapsulated within a dielectric polymer polyvinyl alcohol (PVA), exhibit an augmented inherent capacitance in capacitor assemblies. This discovery not only unveils the potential for cost-effective and highly sensitive capacitive pressure sensors but also underscores prospective applications of these novel patterns in precise motion detection, including heart rate monitoring, and comprehensive analysis of gait profiles. The amalgamation of advanced materials and intricate patterning techniques presents a transformative prospect in the domains of wearable sensing and comprehensive human motion analysis.

6.
Small ; 20(6): e2306394, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37775949

RESUMO

Nanoparticles form long-range micropatterns via self-assembly or directed self-assembly with superior mechanical, electrical, optical, magnetic, chemical, and other functional properties for broad applications, such as structural supports, thermal exchangers, optoelectronics, microelectronics, and robotics. The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. This article provides a comprehensive review of nanoparticle assembly formed primarily via the balance of forces at the nanoscale (e.g., van der Waals, colloidal, capillary, convection, and chemical forces) and nanoparticle-template interactions (e.g., physical confinement, chemical functionalization, additive layer-upon-layer). The review commences with a general overview of nanoparticle self-assembly, with the state-of-the-art literature review and motivation. It subsequently reviews the recent progress in nanoparticle assembly without the presence of surface templates. Manufacturing techniques for surface template fabrication and their influence on nanoparticle assembly efficiency and effectiveness are then explored. The primary focus is the spatial organization and orientational preference of nanoparticles on non-templated and pre-templated surfaces in a controlled manner. Moreover, the article discusses broad applications of micropatterned surfaces, encompassing various fields. Finally, the review concludes with a summary of manufacturing methods, their limitations, and future trends in nanoparticle assembly.

7.
Mol Ecol ; 33(12): e17380, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38745400

RESUMO

In order to thrive and survive, plant species need to combine stability in the long term and rapid response to environmental challenges in the short term. The former would be reflected by parallel or convergent adaptation across species, and the latter by pronounced local adaptation among populations of the same species. In the present study, we generated a high-quality genome and re-sequenced 177 individuals for Gymnocarpos przewalskii, an important desert plant species from North-West China, to detect local adaptation. We first focus on ancient adaptation to aridity at the molecular level by comparing the genomic data of 15 species that vary in their ability to withstand aridity. We found that a total of 118 genes were shared across xerophytic species but absent from non-xerophytic species. Of the 65 found in G. przewalskii, 63 were under purifying selection and two under positive selection. We then focused on local adaptation. Up to 20% of the G. przewalskii genome showed signatures of local adaptation to aridity during population divergence. Thirteen of the selected shared xerophytic genes were reused in local adaptation after population differentiation. Hence, only about 20% of the genes shared and specific to xerophytic species and associated with adaptation to aridity were later recruited for local adaptation in G. przewalskii.


Assuntos
Adaptação Fisiológica , Clima Desértico , Adaptação Fisiológica/genética , China , Genoma de Planta , Seleção Genética , Genes de Plantas , Genética Populacional
8.
Phys Chem Chem Phys ; 26(21): 15494-15510, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38752432

RESUMO

High-level ab initio calculations are conducted for studying the kinetics of three linear pentanol radicals generated through H-atom abstraction reactions. The species involved are optimized using the M06-2X/6-311++G(d,p) level of theory, while a relaxed scan at the M06-2X/6-31g level of theory with 10° increments is used for the hindrance potential for low-frequency torsional modes. Single-point energies for all stationary points are obtained through the QCISD(T) and MP2 methods in combination with cc-pVDZ, cc-pVTZ, and cc-pVQZ basis sets, which can be extrapolated to the complete basis set (CBS) limit. The rate constants and branching ratios for isomerization and decomposition reactions are computed over a temperature range of 250-2000 K and a pressure range of 0.01-100 atm. Isomerization reactions are dominant at low temperatures, while decomposition reactions are more dominant at high temperatures. The branching ratio of the isomerization reaction exhibits a slight decrease with increasing pressure, while the trend for decomposition reactions depends on the type of the breaking bond. Based on the calculations for five branched pentanol radicals in part I, kinetics of linear and branched pentanol radicals are compared in this work and the results reveal that, for the same kind of ß-scission reaction at similar positions of linear and branched pentanol radicals, the rate constants of branched ones are faster than those of linear ones at low temperatures. The hydroxyl group adjacent to the breaking bond can increase the ß-scission reaction rate constants, while the effect can be ignored when the hydroxyl group is not adjacent to the breaking bond. Moreover, compared to when the hydroxyl group is located in the middle of the carbon chain, its positioning at the chain's end yields a more noticeable impact on the products and rate constants of C-O bond and O-H bond ß-scission reactions. Besides, when incorporating calculated rate constants into the CRECK model, the updated mechanism shows a better performance for ignition delay times of 1-pentanol in the NTC range but exhibits lower reactivity at higher temperatures. The simulation of speciation profiles also shows better agreement with the experimental data obtained using a flow reactor.

9.
Small ; 19(50): e2302718, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37501325

RESUMO

Lithium-ion batteries (LIBs) have significantly impacted the daily lives, finding broad applications in various industries such as consumer electronics, electric vehicles, medical devices, aerospace, and power tools. However, they still face issues (i.e., safety due to dendrite propagation, manufacturing cost, random porosities, and basic & planar geometries) that hinder their widespread applications as the demand for LIBs rapidly increases in all sectors due to their high energy and power density values compared to other batteries. Additive manufacturing (AM) is a promising technique for creating precise and programmable structures in energy storage devices. This review first summarizes light, filament, powder, and jetting-based 3D printing methods with the status on current trends and limitations for each AM technology. The paper also delves into 3D printing-enabled electrodes (both anodes and cathodes) and solid-state electrolytes for LIBs, emphasizing the current state-of-the-art materials, manufacturing methods, and properties/performance. Additionally, the current challenges in the AM for electrochemical energy storage (EES) applications, including limited materials, low processing precision, codesign/comanufacturing concepts for complete battery printing, machine learning (ML)/artificial intelligence (AI) for processing optimization and data analysis, environmental risks, and the potential of 4D printing in advanced battery applications, are also presented.

10.
Phys Chem Chem Phys ; 25(26): 17320-17336, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37345723

RESUMO

Theoretical investigations on the kinetics of decomposition and isomerization reactions for five types of branched pentanol radicals are carried out in this work. The M06-2X/6-311++G(d,p) level of theory was used to optimize the geometries of all reactants, transition states, and products, while the hindrance potentials for the lower frequency modes in all of the species were obtained through a relaxed scan with an increment of 10° at the M06-2X/6-31G level of theory. Single-point energies of all species were determined at the QCISD(T)/cc-pVDZ, TZ level of theories with basis set corrections from MP2/cc-pVDZ, TZ, QZ methods. The RRKM/master equation was solved to calculate the pressure- and temperature-dependent rate coefficients for all channels in the pressure range of 0.01-100 atm over 250-2000 K. Pressure and temperature-dependent branching fractions of key species produced from pentanol radicals show that most of the pentanol radical isomers tend to isomerize to alkoxy radicals via a six-membered-ring or five-membered-ring transition state at low temperatures, producing ketones or aldehydes. At higher temperatures, the ß-scission reactions are the main reaction channels for the consumption of pentanol radicals. A weak pressure dependence has been found for all isomerization reactions, and it becomes more and more important as pressure increases. The pressure dependence trends are different for the ß-scission reactions of different branched pentanol radicals. In part I, the results for branched pentanol radical isomers are presented in detail, while in part II the results for linear pentanol radical isomers will be discussed.

11.
Angew Chem Int Ed Engl ; 62(16): e202301262, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-36812298

RESUMO

TFA promoted deprotection of O-Ts activated N-Boc hydroxylamines triggers aminofunctionalization-based polycyclizations of tethered alkenes. The processes involve intramolecular stereospecific aza-Prilezhaev alkene aziridination in advance of stereospecific C-N cleavage by a pendant nucleophile. Using this approach, a wide range of fully intramolecular alkene anti-1,2-difunctionalizations can be achieved, including diaminations, amino-oxygenations and amino-arylations. Trends associated with the regioselectivity of the C-N cleavage step are outlined. The method provides a broad and predictable platform for accessing diverse C(sp3 )-rich polyheterocycles of relevance to medicinal chemistry.

12.
Phys Chem Chem Phys ; 24(41): 25337-25346, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36227270

RESUMO

High-level ab initio calculations were performed to investigate the kinetics of the important initial steps of 2-methyl-2-butanol (2M2B) oxidation. Hydrogen-atom abstraction reactions by hydroxyl (˙OH) radicals, dehydration reactions of 2M2B molecules, and unimolecular isomerization and decomposition reactions of 2M2B radicals produced by H-atom abstraction were all included in this work. The potential energy surfaces were characterized at the QCISD(T)/CBS//M06-2X/6-311++G(d,p) level of theory. Variational transition state theory (VTST) was employed to calculate the rate coefficients for the H-atom abstraction reactions. It is interesting to note that the hydrogen bond formed in the transition state (TS) in H-atom abstraction reactions, leading to a ring-shaped structure, has a large influence on the electronic energy barriers and rotational-vibrational properties of the TS and thus the rate coefficients. For comparison, rate coefficient calculations were carried out for the same reaction channel by employing different types of TS structures separately, with or without hydrogen bonds. For all the unimolecular reactions studied here, pressure-dependent rate coefficients were obtained through Rice-Ramsperger-Kassel-Marcus/master equation (RRKM/ME) calculations at pressures of 0.01-100 atm. In addition, thermochemical properties at temperatures from 300 to 3000 K for all the species in the title reactions were calculated, which were found to be in good agreement with literature data. The kinetics and thermochemical data calculated in this study are important in predicting the combustion properties of 2M2B, which can be used in the combustion kinetic model development of 2M2B oxidation.

13.
Environ Res ; 203: 111844, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364861

RESUMO

This work for the first time reports bimetallic Ni-Co and monometallic (Ni and Co) nanoparticles (NPs)-engineered carbon nitride nanotubes with nitrogen vacancies (V-CNNTs) for visible-light photocatalytic H2 generation application. The bimetallic Ni-Co NPs have an average size of less than 5 nm and are homogenously dispersed along the nanochannels of V-CNNTs. The composition of the bimetallic NPs plays an essential role to maximize photocatalytic activity. With the optimal Ni/Co atom ratio of 3:1, Ni-Co/V-CNNTs nanohybrids yielded a H2 production rate of 4.19 µmol/h, which is higher than those of monometallic counterparts and V-CNNTs. The intimately loaded Ni-Co NPs and incorporated nitrogen vacancies enhance the photocatalytic performance through extended light absorption, abundant active sites, strong metal-support interaction, and efficient charge carrier transfer along the axial direction. This study presents a stable and highly efficient hybrid as a promising photocatalyst for visible light photocatalytic H2 production through water splitting.


Assuntos
Nanopartículas , Nanotubos , Catálise , Hidrogênio , Nitrilas , Nitrogênio
14.
BMC Musculoskelet Disord ; 23(1): 842, 2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36057665

RESUMO

BACKGROUND: Neck pain is widespread among students in healthcare-related fields. Although neck pain is more prevalent in females, since most research involves mixed-sex samples we know very little about sex differences in contributors to neck pain. Thus, this study sought to explore sex differences in the risk factors for neck pain in this high-risk population. METHODS: This cross-sectional study was conducted in China in 2021 and included a sample of 1921 undergraduate healthcare students (693 males, 1228 females) from 7 health professional schools at Fujian Medical University. We collected data on neck pain symptoms, demographics, behavioral and psychological factors. Multiple regression analysis was conducted to examine sex differences in the risk factors of neck pain. RESULTS: The overall prevalence of neck pain was 41.6% with female students having a higher prevalence than male students (44.4% vs. 36.7%, respectively). The adjusted analyses showed that self-study time ≥ 6 h/day (OR = 1.44, 95% CI:1.13-1.83), flexed neck posture >20 degrees (OR = 2.19, 95% CI: 1.28-3.74), static duration posture >2 h (OR = 1.42, 95% CI: 1.02-1.97), and psychological distress (high: OR = 2.04, 95% CI:1.42-2.94; very high: OR = 2.50, 95% CI:1.57-3.74; respectively) were independent factors for neck pain in females. Among males, self-study time ≥ 6 h/day (OR = 1.43, 95% CI: 1.02-2.01) and psychological distress (moderate: OR = 2.04, 95% CI:1.28-3.25; high: OR = 2.37, 95% CI:1.49-3.79; very high: OR = 2.97, 95% CI:1.75-5.02; respectively) were significant risk factors for neck pain. CONCLUSIONS: These findings suggest that the risk profiles of neck pain differ between females and males. The modifiable risk factors for neck pain, such as prolonged self-study time and elevated psychological distress, as well as poor posture among females, could be targeted through health promotion interventions in university settings.


Assuntos
Cervicalgia , Caracteres Sexuais , Estudos Transversais , Atenção à Saúde , Feminino , Humanos , Masculino , Cervicalgia/diagnóstico , Cervicalgia/epidemiologia , Cervicalgia/etiologia , Prevalência , Fatores de Risco , Fatores Sexuais , Estudantes , Inquéritos e Questionários
15.
Angew Chem Int Ed Engl ; 61(34): e202206800, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35770710

RESUMO

A Ti(Oi-Pr)4 promoted 5- or 6-endo-trig cyclisation to make nitrogen heterocycles is presented. The utilisation of HFIP as a key solvent enables the stereoselective preparation of di- & tri-substituted pyrrolidines and piperidines while forming a new C-C bond at the same time. The process is triggered by a cationic intermediate generated from an allylic or benzylic alcohol and leads to the simultaneous generation of both a C-C and a C-N bond in a single step. Notably, either 2,3-trans- or 2,3-cis-substituted heterocycles can be obtained by using a nucleophilic amine bearing different substituents. Lastly, the stereoselective synthesis of enantiopure products was achieved by using readily available enantiopure acyclic starting materials.

16.
Small ; 17(45): e2100817, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34176201

RESUMO

3D printing (additive manufacturing (AM)) has enormous potential for rapid tooling and mass production due to its design flexibility and significant reduction of the timeline from design to manufacturing. The current state-of-the-art in 3D printing focuses on material manufacturability and engineering applications. However, there still exists the bottleneck of low printing resolution and processing rates, especially when nanomaterials need tailorable orders at different scales. An interesting phenomenon is the preferential alignment of nanoparticles that enhance material properties. Therefore, this review emphasizes the landscape of nanoparticle alignment in the context of 3D printing. Herein, a brief overview of 3D printing is provided, followed by a comprehensive summary of the 3D printing-enabled nanoparticle alignment in well-established and in-house customized 3D printing mechanisms that can lead to selective deposition and preferential orientation of nanoparticles. Subsequently, it is listed that typical applications that utilized the properties of ordered nanoparticles (e.g., structural composites, heat conductors, chemo-resistive sensors, engineered surfaces, tissue scaffolds, and actuators based on structural and functional property improvement). This review's emphasis is on the particle alignment methodology and the performance of composites incorporating aligned nanoparticles. In the end, significant limitations of current 3D printing techniques are identified together with future perspectives.


Assuntos
Nanopartículas , Nanoestruturas , Impressão Tridimensional , Alicerces Teciduais
17.
Subst Use Misuse ; 56(10): 1457-1466, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34139949

RESUMO

Background: Studies have shown that psychological resilience is a key factor in drug rehabilitation. To explore the feasibility of developing psychological resilience as an addiction treatment intervention, it is essential to explore the role that it plays in drug addiction. Objectives: This study aimed to investigate the relationship between psychological resilience and drug addiction, as well as to examine the underlying mediational roles of maladjustment and impulsiveness in this association. Methods: We used a cross-sectional design that included a sample of 140 male drug addicts in compulsory isolation centers and used questionnaires and scales to ascertain their level of drug addiction, psychological resilience, maladjustment, impulsiveness, social support, and loneliness. Correlation and mediation effect analyses were performed to determine the roles of impulsiveness and maladjustment in the association of psychological resilience with drug addiction. Results: Psychological resilience was an inverse predictor of drug addiction. The results of the mediation effect analysis showed that maladjustment acted as a mediator between resilience and drug addiction and between impulsiveness and drug addiction. Furthermore, impulsiveness and maladjustment jointly mediated the relationship between psychological resilience and drug addiction. Conclusion: These findings highlight the importance of psychological resilience in maladjustment and impulsiveness for drug addicts and suggest that the role of psychological resilience in drug addiction needs to be further explored.


Assuntos
Resiliência Psicológica , Transtornos Relacionados ao Uso de Substâncias , Estudos Transversais , Humanos , Solidão , Masculino , Apoio Social
18.
J Am Chem Soc ; 141(16): 6489-6493, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-30977361

RESUMO

A new method for the stereoselective synthesis of highly functionalized oxygen heterocycles using allyl or benzyl alcohols as alkylating agents is presented. The process is efficient and atom economic, generating water as the only stoichiometric byproduct. Substoichiometric amounts of Ti(OiPr)4 in HFIP solvent are key to this reactivity, and the method tolerates a broad substitution pattern on both the alcohol initiator and homoallylic alcohol substrate. Preliminary mechanistic studies reveal in situ formation of a titanium complex with HFIP which may initiate the cyclization reaction. Further stereoselective functionalization of the products allows access to a diverse range of interesting heterocyclic structures.

19.
Nano Lett ; 18(10): 6113-6120, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30169958

RESUMO

Solid electrolytes are crucial for the development of solid state batteries. Among different types of solid electrolytes, poly(ethylene oxide) (PEO)-based polymer electrolytes have attracted extensive attention owing to their excellent flexibility and easiness for processing. However, their relatively low ionic conductivities and electrochemical instability above 4 V limit their applications in batteries with high energy density. Herein, we prepared poly(vinylidene fluoride) (PVDF) polymer electrolytes with an organic plasticizer, which possesses compatibility with 4 V cathode and high ionic conductivity (1.2 × 10-4 S/cm) at room temperature. We also revealed the importance of plasticizer content to the ionic conductivity. To address weak mechanical strength of the PVDF electrolyte with plasticizer, we introduced palygorskite ((Mg,Al)2Si4O10(OH)) nanowires as a new ceramic filler to form composite solid electrolytes (CPE), which greatly enhances both stiffness and toughness of PVDF-based polymer electrolyte. With 5 wt % of palygorskite nanowires, not only does the elastic modulus of PVDF CPE increase from 9.0 to 96 MPa but also its yield stress is enhanced by 200%. Moreover, numerical modeling uncovers that the strong nanowire-polymer interaction and cross-linking network of nanowires are responsible for such significant enhancement in mechanically robustness. The addition of 5% palygorskite nanowires also enhances transference number of Li+ from 0.21 to 0.54 due to interaction between palygorskite and ClO4- ions. We further demonstrate full cells based on Li(Ni1/3Mn1/3Co1/3)O2 (NMC111) cathode, PVDF/palygorskite CPE, and lithium anode, which can be cycled over 200 times at 0.3 C, with 97% capacity retention. Moreover, the PVDF matrix is much less flammable than PEO electrolytes. Our work illustrates that the PVDF/palygorskite CPE is a promising electrolyte for solid state batteries.

20.
Tumour Biol ; 36(10): 8025-34, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25971583

RESUMO

The SOX17 (SRY-related HMG-box) transcription factor is involved in a variety of biological processes and is related to the tumorigenesis and progression of multiple tumors. However, the clinical application of SOX17 for breast cancer prognosis is currently limited. The aim of this study was to investigate the clinicopathologic and prognostic significance of SOX17 expression in human breast cancer. qPCR and western blot assays were performed to measure the expression of SOX17 in breast cancer cell lines and 30 matched pairs of breast cancer and corresponding noncancerous tissues. A SOX17 overexpression cell model was used to examine changes in cell growth in vitro. Immunohistochemical analyses were performed to retrospectively examine the prognostic impact of SOX17 expression in 187 additional breast cancer patients. Our results showed that SOX17 expression was decreased at both the messenger RNA (mRNA) and protein levels in the breast cancer cell lines and tissues, and that SOX17 overexpression could strongly suppress cell growth in vitro. Furthermore, the lack of SOX17 protein expression was strongly correlated with higher tumor grade (P = 0.002), lymph node metastasis (P < 0.001), and tumor node metastasis (TNM) stage (P = 0.001) and had poorer disease-free survival (DFS) and overall survival (OS) compared to normal SOX17 expression (P = 0.002 and 0.001, respectively). Univariate and multivariate analyses indicated that lower SOX17 expression was an independent prognostic factor for DFS (P = 0.007; HR = 2.854; 95 % CI 1.326-6.147) and OS (P = 0.005; HR = 5.035; 95 % CI 1.648-15.385) for breast cancer. Our findings indicate that SOX17 expression is a useful prognostic biomarker for breast cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Mama/metabolismo , Fatores de Transcrição SOXF/metabolismo , Adulto , Idoso , Apoptose , Biomarcadores Tumorais/genética , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Estudos de Casos e Controles , Proliferação de Células , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXF/genética , Taxa de Sobrevida , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA