Highlights
Interface engineering of heterogeneous CoS/CoO nanocrystals and N-doped graphene composite facilitates high-performance oxygen reduction reaction and oxygen evolution reaction.
Density ...functional theory calculations and experimental results confirm the enhanced electrocatalytic performances via the proposed interface engineering.
The bifunctional oxygen electrocatalyst exhibits excellent performances in rechargeable Zn–air batteries.
Low cost and green fabrication of high-performance electrocatalysts with earth-abundant resources for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for the large-scale application of rechargeable Zn–air batteries (ZABs). In this work, our density functional theory calculations on the electrocatalyst suggest that the rational construction of interfacial structure can induce local charge redistribution, improve the electronic conductivity and enhance the catalyst stability. In order to realize such a structure, we spatially immobilize heterogeneous CoS/CoO nanocrystals onto N-doped graphene to synthesize a bifunctional electrocatalyst (CoS/CoO@NGNs). The optimization of the composition, interfacial structure and conductivity of the electrocatalyst is conducted to achieve bifunctional catalytic activity and deliver outstanding efficiency and stability for both ORR and OER. The aqueous ZAB with the as-prepared CoS/CoO@NGNs cathode displays a high maximum power density of 137.8 mW cm
−2
, a specific capacity of 723.9 mAh g
−1
and excellent cycling stability (continuous operating for 100 h) with a high round-trip efficiency. In addition, the assembled quasi-solid-state ZAB also exhibits outstanding mechanical flexibility besides high battery performances, showing great potential for applications in flexible and wearable electronic devices.
As a broad-spectrum antibiotic, tetracycline (TC) is widely used in agricultural purposes and human therapy. More attention is paid to TC as a serious threat to human health, including the fast ...spreading of antibiotic resistance gene and the serious toxicity to aquatic organisms. Therefore, the timely and accurate determination of TC residues is an urgent task to protect the safety of human. Herein, an effective and facile photoelectrochemical sensor platform based on carbon nitride/bismuth oxyhalide (CN/BiOBr) composites can be constructed for monitoring TC. The flower-like CN/BiOBr composites are prepared via a simple one-pot ethylene glycol-assisted solvothermal process with the addition of ionic liquid 1-hexadecyl-3-methylimidazolium bromide (C16mimBr). In view of matched energy band positions of CN and BiOBr, the addition of CN can reduce the recombination of photogenerated electron-hole pairs and improve the efficiency of visible light utilization, leading to enhancing photoelectrochemical response of BiOBr. Under light excitation, the photocurrent of CN/BiOBr composites is drastically improved, which is 6 times as much as that of pure BiOBr. Considering the superior photoelectrochemical performance, a photoelectrochemical sensor for monitoring TC has been developed, displaying linearly enhanced photocurrent with increasing the TC concentration. Two linear relationships received are from 8.0 to 4.0 × 102 ng mL−1, and 4.0 × 102 to 5.2 × 103 ng mL−1, respectively. The detection limit is 3.8 ng mL−1. The photoelectrochemical sensor exhibits a series of benefits including excellent stability, a wide linear range, a low detection limit and good anti-interference ability. Therefore, this work may offer great promises in providing a universal and efficient photoelectrochemical sensor for the tetracycline detection, and pave the way of constructing more materials used in photoelectrochemical detection field.
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•A photoelectrochemical sensing platform is fabricated for tetracycline detection.•The photoelectrochemical sensor is based on the flower-like CN/BiOBr composites.•The CN/BiOBr has been prepared by ionic liquid-associated solvothermal method.•The photoelectrochemical sensor shows wide detectable range and low detection limit.
As a broad-spectrum tetracycline antibiotic, the overuse of oxytetracycline (OTC) causes antibiotics residues in the environment and seriously threats to human health owing to effective antibacterial ...properties. Thus, it is particularly important to design a photoelectrochemical (PEC) aptasensor to detect OTC with excellent performance. Herein, we developed a selective and stable PEC aptasensor of OTC on the basis of Co3O4 nanoparticles (Co3O4 NPs)/graphitic carbon nitride (g-CN) heterojunction, used as PEC active materials. The Co3O4 NPs were successfully grown on the g-CN via grinding and calcining mixture of Co3O4 precursors and bulk g-CN. The Co3O4/g-CN heterojunction with improved light utilization and promoted electrons/holes separation capability can exhibit higher PEC signal than that of g-CN. In order to implement the purpose of specific recognition, OTC-aptamer was introduced into modified electrode to construct highly selective PEC aptasensor for OTC determination, which can possess wide linear range (0.01–500 nM) with low detection limit (3.5 pM, S/N = 3). This PEC aptasensor platform with excellent selectivity and high stability can provide a practical application in the field of water monitoring.
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•Co3O4-based photoactive materials was reported for detecting OTC.•The PEC aptasensor for OTC detection possessed low detection limit of 3.5 pM and excellent selectivity.•The PEC aptasensor has been applied in real water samples for OTC detection.
One of the crucial issues in rechargeable zinc-air batteries is to explore low-cost, highly efficient bifunctional electrocatalysts for the oxygen reduction/evolution reaction. Here, the unique NiCo ...alloy nanoparticles encapsulated in the multi-dimensional nitrogen-doped carbon architecture (NiCo/MNC) is reported as an effective bifunctional catalyst for rechargeable zinc-air batteries. The multi-dimensional nitrogen-doped carbon architecture was synthesized through the rapid calcination of two-dimensional graphitic carbon nitride (g-C3N4) and one-dimensional multi-walled carbon nanotubes (MWCNTs). The g-C3N4 serves as the nitrogen source and the precursor for N-doped carbon nanosheets (NCSs). Simultaneously, NCSs can intertwine with MWCNTs to further obtain the multi-dimensional architecture with a large specific surface area. The synergistic effect between multi-dimensional nitrogen-doped carbon architectures and NiCo alloy nanoparticles endowed the NiCo/MNC with a positive half-wave potential of 0.83 V (vs. RHE: Reversible Hydrogen Electrode) for oxygen reduction reaction and a low potential of 1.61 V (vs. RHE) at the current density of 10 mA cm−2 for oxygen evolution reaction. Moreover, the zinc-air battery assembled with NiCo/MNC as the air-cathode exhibited a high-power density of 135.2 mW cm−2, a specific capacity of 701.7 mAh g−1, and an excellent stability in charging/discharging cycle test (over 115 h). The prepared catalyst could potentially serve to take the place of precious metal catalysts in rechargeable zinc-air batteries.
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•NiCo alloy nanoparticles encapsulated in the multi-dimensional N-doped carbon (MNC) architecture was designed.•The synergistic effect between MNC and NiCo alloy nanoparticles can facilitate ORR/OER activities.•NiCo/MNC serves as an efficient ORR/OER catalyst for rechargeable zinc−air batteries.
Convolutional Neural Networks (CNNs) have been widely used in various fields due to their high accuracy and efficiency. The performance of CNNs is mainly affected by the computing capability, memory ...bandwidth, and flexibility of embedded devices. The high energy efficiency, computing capability, and reconfigurability of FPGAs make it a good platform for hardware acceleration in the design of CNNs. However, the increase of complexity of CNNs, requires memory while the FPGA on-chip storage is limited. Therefore, we use an improved logarithmic quantization to compress the model. This approach allows for significant reduction in bit widths while maintaining high accuracy levels, making it an effective compression method. In this work, a hardware-friendly quantization scheme is proposed, in which the weights use improved logarithmic quantization scheme, and the quantization scheme of activations use the fixed-point-to-logarithmic. The results show that the quantization model has negligible Top-1/5 accuracy loss without any retraining. In addition, we implement an acceleration engine for a heterogeneous Generalized Matrix Multiplication (GEMM) core on Zynq XC7Z020. In GEMM, the multiplier is replaced by logic shifters and adders, which achieves efficient utilization of LUT resources. We use the optimal quantization model on Zynq XC7Z020. The throughput reaches 69.7 GOPs with a power consumption of 6.008W, and the resource efficiency is 8.713 GOPs/DSP or 5.564 GOPs/kLUTs.
Large magnetic nanoparticles or aggregates are advantageous in their magnetic resonance properties over ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles (NPs), but the former are cleared ...faster from the blood pool. Therefore, the “smart” strategy of intracellular aggregation of USPIO NPs is required for enhanced T 2-weighted MR imaging. Herein, employing an enzyme-instructed condensation reaction, we rationally designed a small molecule Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys-CBT (1) to covalently modify USPIO NPs to prepare monodispersive Fe3O4@1 NPs. In vitro results showed that Fe3O4@1 NPs could be subjected to caspase 3 (Casp3)-instructed aggregation. T2 phantom MR imaging showed that the transverse molar relaxivity (r 2) of Fe3O4@1 NPs with Casp3 or apoptotic HepG2 cells was significantly larger than those of control groups. In vivo tumor MR imaging results indicated that Fe3O4@1 NPs could be specifically applied for enhanced T 2 MR imaging of tumor apoptosis. We propose that the enzyme-instructed intracellular aggregation of Fe3O4 NPs could be a novel strategy for the design of “smart” probes for efficient T 2 MR imaging of in vivo biomarkers.
A nanocomposite of α-Fe
2
O
3
/alkalinized C
3
N
4
(α-Fe
2
O
3
/A-C
3
N
4
) electrocatalyst for oxygen reduction reaction (ORR) was synthesized by a simple in situ electrostatic adsorption of A-C
3
N
...4
and iron-based ionic liquid OmimFeCl
4
complexation reaction using sonication treatment followed by pyrolysis process. The as-prepared α-Fe
2
O
3
/A-C
3
N
4
nanocomposite can act as a superior electrocatalyst for ORR in terms of excellent ORR activity with onset potential of 0.82 V vs. reversible hydrogen electrodes (RHE), current density of 5.2 mA cm
−2
and outstanding methanol resistance. This cost-effective starting materials and simple preparation method paves the way to large-scale fabrication of low-cost and highly active noble metal-free electrocatalyst and promotes their practical applications in electrochemical power conversion and storage system.
Graphical abstract
Cerium oxide nanoparticles (CeO
NPs) have potential application for use in biomedical and in various consumer products. However, it is largely unclear whether CeO
NPs have effects on male ...reproductive function.
In this study, male mice were examined for toxicity, if any, following chronic oral administration of CeO
NPs for 32 days. In each animal, epididymides were examined for sperm motility and DNA integrity. Bloods were tested for testosterone levels. Testicular tissues were collected to determine the element Ce content, the daily sperm production (DSP), marker enzymes such as ACP, G6PD, γ-GT and SDH, mRNA expression levels of steroidogenesis genes Star, P450scc, P450c17, 3β-Hsd, and 17β-Hsd, as well as steroidogenic factor-1 (SF-1) gene/protein levels.
The results showed that CeO
NPs (20 mg/kg and 40 mg/kg) increased the element Ce content in testis, the testis histopathological patterns and sperm DNA damage whereas decreased the testis weight, DSP and sperm motility. There were also remarkable reduction in testosterone levels and marker enzymes activities, down-regulated mRNA expression levels of several steroidogenesis genes such as Star, P450scc, P450c17, 3β-Hsd, and 17β-Hsd, as well as altered gene and protein expressions of SF-1.
These results reveal the male reproductive toxicity of chronic exposure of CeO
NPs in mice, hinting that the utilization of CeO
NPs need to be carefully evaluated about their potential reproductive toxicity on the human health.
N-doped TiO
2
fiber membranes were prepared by electrospinning method and adsorptive chitosan was added as a nitrogen source. The obtained TiO
2
fiber membranes were analyzed by scanning electron ...microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results show that the film has adsorption properties; furthermore, the morphology of the TiO
2
fiber with a chitosan content of 0.5 g after calcination provides the best catalytic performance; An anatase–rutile titania was found in the oxidized fiber film found in the Raman spectrum TiO
2
; XPS demonstrated that the introduction of chitosan could replace N atom with partial lattice oxygen in TiO
2
. Moreover, the degradation rate of methylene blue of the material was about 60–80% after 4-h reaction, and the maximum degradation rate was achieved by nanofiber film with chitosan concentration of 0.5 g.
This study aimed to determine the prognostic value of the sarcopenia on the progression free survival (PFS) and overall survival (OS) of esophageal squamous cell cancer (ESCC) patients who received ...radiotherapy (RT) or chemoradiotherapy (CRT).
Data on clinicopathological characteristics and nutritional parameters were analyzed and correlated with PFS and OS, retrospectively. Skeletal muscle, subcutaneous, visceral and total fat tissue cross-sectional areas were evaluated on CT images at the midpoint of the 3rd lumbar vertebrae. A total of 213 patients were enrolled in this study.
Sarcopenia was significantly associated with subcutaneous fat content. The univariate analysis demonstrated that OS was superior in patients with non-sarcopenia, non-alcohol, NRI ≥ 100, albumin ≥ 40 g/L, TATI > 83.0, SATI > 27.8, VATI > 49, non-anemia, cervical and upper-thoracic ESCC, T stage 1-2, N stage 0-1 and TNM stage I-II. In the multivariate analysis, sarcopenia, albumin, N stage and TNM stage were identified as independent prognostic factors of survival. This study demonstrated that sarcopenia was related to worse PFS and OS in patients with ESCC who received RT or CRT.
Sarcopenia is considered to be a useful predictor in patients with ESCC who received RT or CRT. This study also provided a conceptual basis for further prospective research on the application of the sarcopenia for patients receiving RT or CRT for intermediate- and advanced-stage ESCC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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