Magnetically Enhanced Oxygen Evolution Reaction in Mild Alkaline Electrolytes by Building Catalysts on Magnetic Frame.

Under large current densities, the excessive hydroxide ion (OH) consumption hampers alkaline water splitting involving the oxygen evolution reaction (OER). High OH concentration (≈30 wt.%) is often used to enhance the catalytic activity of OER, but it also leads to higher corrosion in practical systems. To achieve higher catalytic activity in low OH concentration, catalysts on magnetic frame (CMF) are built to utilize the local magnetic convection induced from the host frame's magnetic field distributions. This way, a higher reaction rate can be achieved in relatively lower OH concentrations. A CMF model system with catalytically active CoFeOx nanograins grown on the magnetic Ni foam is demonstrated. The OER current of CoFeOx@NF receives ≈90% enhancement under 400 mT (900 mA cm-2 at 1.65 V) compared to that in zero field, and exhibits remarkable durability over 120 h. As a demonstration, the water-splitting performance sees a maximum 45% magnetic enhancement under 400 mT in 1 m KOH (700 mA cm-2 at 2.4 V), equivalent to the concentration enhancement of the same electrode in a more corrosive 2 m KOH electrolyte. Therefore, the catalyst-on-magnetic-frame strategy can make efficient use of the catalysts and achieve higher catalytic activity in low OH concentration by harvesting local magnetic convection.

Biomass carbon and Ti2C3MXene quantum dots as ratiometric fluorescent probes for sensitive detecting malachite green in fish sample.

A visual detection method for malachite green (MG) in food was established based on 'double-response-OFF' ratiometric fluorescent paper-based sensor. Biomass carbon quantum dots (BCQDs) using broad bean shell, and Ti3C2MXene quantum (MQDs) dots modified by ethylenediamine were synthesized by solvothermal method. The MG and two kinds of quantum dots could undergo static quenching, and the fluorescence color of two kinds of quantum dots gradually changed from red to blue, eventually the fluorescence was quenched, and the pattern had a two-stage linear relationship using fluorescent spectrofluorometer in the range of 0.1-140.0µM and the detection limit of 0.07µM. On this basis, a BCQDs/MQDs ratiometric fluorescence paper-based sensor was constructed and applied to fish sample. Through mobile phone software-Color recognizer, RGB values of fluorescent paper-based sensor at various concentrations of MG were extracted. The results showed that MG concentration was linearly correlated withR' value of RGB in the range of 20.0-140.0µM with 16.5µM detection limit. The method had been applied to the determination of canned fish and fresh basa fish samples, and the recovery rates were 97.33%-108.93% and 96.04%-117.97%, respectively. It proved that the ratiometric fluorescent paper-based sensor could be used for the rapid visual quantitative detecting MG in real samples.

Protective effect of onion peel extract on ageing mouse oocytes.

Mammalian oocytes not fertilized immediately after ovulation can undergo ageing and a rapid decline in quality. The addition of antioxidants can be an efficient approach to delaying the oocyte ageing process. Onion peel extract (OPE) contains quercetin and other flavonoids with natural antioxidant activities. In this study, we investigated the effect of OPE on mouse oocyte ageing and its mechanism of action. The oocytes were aged in vitro in M16 medium for 16 h after adding OPE at different concentrations (0, 50, 100, 200, and 500 µg/ml). The addition of 100 µg/ml OPE reduced the oocyte fragmentation rate, decreased the reactive oxygen species (ROS) level, increased the glutathione (GSH) level, and improved the mitochondrial membrane potential compared with the control group. The addition of OPE also increased the expression of SOD1, CAT, and GPX3 genes, and the caspase-3 activity in OPE-treated aged oocytes was significantly lower than that in untreated aged oocytes and similar to that in fresh oocytes. These results indicated that OPE delayed mouse oocyte ageing by reducing oxidative stress and apoptosis and enhancing mitochondrial function.

Recent Advances in the Synthesis of Aromatic Azo Compounds.

Aromatic azo compounds have -N=N- double bonds as well as a larger π electron conjugation system, which endows aromatic azo compounds with wide applications in the fields of functional materials. The properties of aromatic azo compounds are closely related to the substituents on their aromatic rings. However, traditional synthesis methods, such as the coupling of diazo salts, have a significant limitation with respect to the structural design of aromatic azo compounds. Therefore, many scientists have devoted their efforts to developing new synthetic methods. Moreover, recent advances in the synthesis of aromatic azo compounds have led to improvements in the design and preparation of light-response materials at the molecular level. This review summarizes the important synthetic progress of aromatic azo compounds in recent years, with an emphasis on the pioneering contribution of functional nanomaterials to the field.

Nucleosome positioning based on DNA sequence embedding and deep learning.

BACKGROUND: Nucleosome positioning is the precise determination of the location of nucleosomes on DNA sequence. With the continuous advancement of biotechnology and computer technology, biological data is showing explosive growth. It is of practical significance to develop an efficient nucleosome positioning algorithm. Indeed, convolutional neural networks (CNN) can capture local features in DNA sequences, but ignore the order of bases. While the bidirectional recurrent neural network can make up for CNN's shortcomings in this regard and extract the long-term dependent features of DNA sequence. RESULTS: In this work, we use word vectors to represent DNA sequences and propose three new deep learning models for nucleosome positioning, and the integrative model NP_CBiR reaches a better prediction performance. The overall accuracies of NP_CBiR on H. sapiens, C. elegans, and D. melanogaster datasets are 86.18%, 89.39%, and 85.55% respectively. CONCLUSIONS: Benefited by different network structures, NP_CBiR can effectively extract local features and bases order features of DNA sequences, thus can be considered as a complementary tool for nucleosome positioning.

Facile bimetallic co-amplified electrochemical sensor for folic acid sensing based on CoNPs and CuNPs.

Folic acid (FA) is essential for human health, particularly for pregnant women and infants. In this work, a glassy carbon electrode (GCE) was modified by a bimetallic layer of Cu/Co nanoparticles (CuNPs/CoNPs) as a synergistic amplification element by simple step-by-step electrodeposition, and was used for sensitive detection of FA. The proposed CuNPs/CoNPs/GCE sensor was characterized by differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and field emission scanning electron microscopy (FESEM). Then, under optimal conditions, a linear relationship was obtained in the wide range of 110.00-1750.00 µM for the detection of FA with a limit of detection (LOD) of 34.79 µM (S/N = 3). The sensitivity was calculated as 0.096 µA µM-1 cm-2. Some interfering compounds including glucose (Glc), biotin, dopamine (DA), and glutamic acid (Glu) showed little effect on the detection of FA by amperometry (i-t). Finally, the average recovery obtained was in a range of 91.77-110.06%, with a relative standard deviation (RSD) less than 8.00% in FA tablets, indicating that the proposed sensor can accurately and effectively detect the FA content in FA tablets.

Na3V2(PO4)2F3@bagasse carbon as cathode material for lithium/sodium hybrid ion battery.

The nano-scale spherical Na3V2(PO4)2F3 with a NASICON structure phase was prepared with a spray drying technique, and the bagasse in Guangxi, China was selected as the carbon source to prepare Na3V2(PO4)2F3/C. The optimal preparation conditions of the composite determined using thermogravimetry, X-ray diffraction, scanning electron microscopy and electrochemical testing were: a calcination temperature of 650 °C and a 20% carbon source. The Na3V2(PO4)2F3/C has obvious redox peaks, determined by cyclic voltammetry (CV), at 3.90 V and 3.75 V, 4.32 V and 4.15 V. These two pairs of redox peaks correspond to the escape/intercalation of the two pairs of Li+/Na+. Notably, compared with pure Na3V2(PO4)2F3, the specific discharge capacity of Na3V2(PO4)2F3/C-20%, which were used as a cathode material for lithium-sodium hybrid ion batteries, increased from 55 mA h g-1 to 125 mA h g-1, which was an improvement of twofold.

Comparative analysis and prediction of nucleosome positioning using integrative feature representation and machine learning algorithms.

BACKGROUND: Nucleosome plays an important role in the process of genome expression, DNA replication, DNA repair and transcription. Therefore, the research of nucleosome positioning has invariably received extensive attention. Considering the diversity of DNA sequence representation methods, we tried to integrate multiple features to analyze its effect in the process of nucleosome positioning analysis. This process can also deepen our understanding of the theoretical analysis of nucleosome positioning. RESULTS: Here, we not only used frequency chaos game representation (FCGR) to construct DNA sequence features, but also integrated it with other features and adopted the principal component analysis (PCA) algorithm. Simultaneously, support vector machine (SVM), extreme learning machine (ELM), extreme gradient boosting (XGBoost), multilayer perceptron (MLP) and convolutional neural networks (CNN) are used as predictors for nucleosome positioning prediction analysis, respectively. The integrated feature vector prediction quality is significantly superior to a single feature. After using principal component analysis (PCA) to reduce the feature dimension, the prediction quality of H. sapiens dataset has been significantly improved. CONCLUSIONS: Comparative analysis and prediction on H. sapiens, C. elegans, D. melanogaster and S. cerevisiae datasets, demonstrate that the application of FCGR to nucleosome positioning is feasible, and we also found that integrative feature representation would be better.

Primary cardiac lymphoma: the management and outcome of a single-centre cohort of 22 patients.

BACKGROUND: The incidence of primary cardiac lymphoma (PCL) is increasing, but the optimal management approach remains unclear. We assessed the clinical characteristics of a single-centre cohort with the goal of determining the optimal management approach. The treatment outcomes and prognostic factors are reported. MATERIAL AND METHODS: All PCL patients were diagnosed via biopsy guided by whole-body imaging (positron emission tomography/computed tomography [PET/CT] and/or contrast-enhanced CT]. Curative therapy involved either surgery or prephase steroids followed by definitive immunochemotherapy, depending on the histological type. The primary outcomes were overall survival (OS) and progression-free survival (PFS); the secondary outcome was the treatment response. RESULTS: Twenty-two PCL patients (14 males, 8 females; age: 59.5 ± 14.7 years [mean ± S.D.]) were histologically confirmed to have diffuse large B-cell lymphoma (DLBCL; n = 17 [77.3%]), fibrin-associated DLBCL (FA-DLBCL) (n = 4 [18.2%]) and Burkitt lymphoma (n = 1 [4.5%]). Seven patients underwent cardiotomy (three for biopsy, four with curative intent). The median and longest follow-up periods were 16.3 and 180.0 months, respectively. The 16 patients who received curative therapy (complete response [CR], n = 15 [93.8%]; partial response [PR], n = 1 [6.2%]) showed better survival than those who did not (5-year OS: 83.0 ± 11.3% vs. 0%; hazard ratio [HR]: 0.025[95% confidence interval, CI: 0.003-0.187], p < 0.001); 5-year PFS: 78.7 ± 11.0% vs. 0%, HR= 0.010[0.001-0.093], p < 0.001). The left ventricular ejection fractions (LVEF) before and after definitive treatment was 63.6 ± 2.4% and 64.6 ± 4.5%, respectively (p = 0.275, power = 0.318). Extrapericardial lesions were associated with poorer survival (5-year OS: 40.0 ± 29.7% vs. 100%, p = 0.027; 5-year PFS:40.0 ± 21.9% vs. 100%, p = 0.010). CONCLUSIONS: Whole-body imaging is essential for diagnosis and prognosis. Curative therapy provided reasonable outcomes and survival; extrapericardial lesions were associated with a poorer treatment response.

Multiscale adaptive multifractal analysis and its applications.

To precisely analyze the fractal nature of a short-term time series under the multiscale framework, this study introduces multiscale adaptive multifractal analysis (MAMFA) combining the adaptive fractal analysis method with the multiscale multifractal analysis (MMA). MAMFA and MMA are both applied to the two kinds of simulation sequences, and the results show that the MAMFA method achieves better performances than MMA. MAMFA is also applied to the Chinese and American stock indexes and the R-R interval of heart rate data. It is found that the multifractal characteristics of stock sequences are related to the selection of the scale range s. There is a big difference in the Hurst surface's shape of Chinese and American stock indexes and Chinese stock indexes have more obvious multifractal characteristics. For the R-R interval sequence, we find that the subjects with abnormal heart rate have significant shape changes in three areas of Hurst surface compared with healthy subjects, thereby patients can be effectively distinguished from healthy subjects.

Verbascoside inhibits progression of glioblastoma cells by promoting Let-7g-5p and down-regulating HMGA2 via Wnt/beta-catenin signalling blockade.

Glioblastoma (GBM) continues to show a poor prognosis despite advances in diagnostic and therapeutic approaches. The discovery of reliable prognostic indicators may significantly improve treatment outcome of GBM. In this study, we aimed to explore the function of verbascoside (VB) in GBM and its effects on GBM cell biological processes via let-7g-5p and HMGA2. Differentially expressed GBM-related microRNAs (miRNAs) were initially screened. Different concentrations of VB were applied to U87 and U251 GBM cells, and 50 µmol/L of VB was selected for subsequent experiments. Cells were transfected with let-7g-5p inhibitor or mimic, and overexpression of HMGA2 or siRNA against HMGA2 was induced, followed by treatment with VB. The regulatory relationships between VB, let-7g-5p, HMGA2 and Wnt/ß-catenin signalling pathway were determined. The results showed that HMGA2 was a direct target gene of let-7g-5p. VB treatment or let-7g-5p overexpression inhibited HMGA2 expression and the activation of Wnt/ß-catenin signalling pathway, which further inhibited cell viability, invasion, migration, tumour growth and promoted GBM cell apoptosis and autophagy. On the contrary, HMGA2 overexpression promoted cell viability, invasion, migration, tumour growth while inhibiting GBM cell apoptosis and autophagy. We demonstrated that VB inhibits cell viability and promotes cell autophagy in GBM cells by up-regulating let-7g-5p and down-regulating HMGA2 via Wnt/ß-catenin signalling blockade.

Timing Metabolic Depression: Predicting Thermal Stress in Extreme Intertidal Environments.

AbstractAnticipatory changes in organismal responses, triggered by reliable environmental cues for future conditions, are key to species' persistence in temporally variable environments. Such responses were tested by measuring the physiological performance of a tropical high-shore oyster in tandem with the temporal predictability of environmental temperature. Heart rate of the oyster increased with environmental temperatures until body temperature reached ∼37°C, when a substantial depression occurred (∼60%) before recovery between ∼42° and 47°C, after which cardiac function collapsed. The sequential increase, depression, and recovery in cardiac performance aligned with temporal patterns in rock surface temperatures, where the risk of reaching temperatures close to the oysters' lethal limit accelerates if the rock heats up beyond ∼37°C, coinciding closely with the body temperature at which the oysters initiate metabolic depression. The increase in body temperature over a critical threshold serves as an early-warning cue to initiate anticipatory shifts in physiology and energy conservation before severe thermal stress occurs on the shore. Cross-correlating the onset of physiological mechanisms and temporal structures in environmental temperatures, therefore, reveals the potential role of reliable real-time environmental cues for future conditions in driving the evolution of anticipatory responses.

miRNA-574-5p downregulates ZNF70 and influences the progression of human esophageal squamous cell carcinoma through reactive oxygen species generation and MAPK pathway activation.

There is growing evidence shown that microRNAs (miRNAs) are associated with cancer and can play a role in human cancers as oncogenes or tumor suppressor genes. miRNA-574-5p is a candidate oncogene in various types of cancer, but little is known about biological functions of miR-574-5p in esophageal squamous cell carcinoma (ESCC). In this study, we observe that the expression of miR-574-5p is not only increased in human ESCC tissues but also remarkably increased in cell lines correlates with ZNF70. In vitro, we explored the role of miR-574-5p in ESCC progression via transfection of the miR-574-5p inhibitor into ECA-109 cells. The results show miR-574-5p serve as a tumor promoter regulating cells proliferation and apoptosis in ESCC through mitochondrial-mediated reactive oxygen species (ROS) generation and MAPK pathways. Furthermore, ZNF70 has been proved to as a functional target for miR-574-5p to regulate cells poliferation and apoptosis. In summary, these results suggest that miR-574-5p serves as tumor promoter to promote proliferation and inhibit apoptosis of ESCC cells by targeting ZNF70 via mitochondrial-mediated ROS generation and MAPK pathways. The miR-574-5p/ZNF70 pathway provides a new insight into the molecular mechanisms that the occurrence and development of ESCC and it provides a novel therapeutic target for ESCC.

Randomized multifractal detrended fluctuation analysis of long time series.

A novel general randomized method is proposed to investigate multifractal properties of long time series. Based on multifractal temporally weighted detrended fluctuation analysis (MFTWDFA), we obtain randomized multifractal temporally weighted detrended fluctuation analysis (RMFTWDFA). The innovation of this algorithm is applying a random idea in the process of dividing multiple intervals to find the local trend. To test the performance of the RMFTWDFA algorithm, we apply it, together with the MFTWDFA, to the artificially generated time series and real genomic sequences. For three types of artificially generated time series, consistency tests are performed on the estimated h(q), and all results indicate that there is no significant difference in the estimated h(q) of the two methods. Meanwhile, for different sequence lengths, the running time of RMFTWDFA is reduced by over ten times. We use prokaryote genomic sequences with large scales as real examples, the results obtained by RMFTWDFA demonstrate that these genomic sequences show fractal characteristics, and we leverage estimated exponents to study phylogenetic relationships between species. The final clustering results are consistent with real relationships. All the results reflect that RMFTWDFA is significantly effective and timesaving for long time series, while obtaining an accuracy statistically comparable to other methods.

A Facile Electrochemical Sensor Labeled by Ferrocenoyl Cysteine Conjugate for the Detection of Nitrite in Pickle Juice.

Simple and facile electrochemical sensors for nitrite detection were fabricated by directly depositing ferrocenoyl cysteine conjugates Fc[CO-Cys(Trt)-OMe]2 [Fc(Cys)2] or Fc[CO-Glu-Cys-Gly-OH] [Fc-ECG] on screen-printed electrodes (SPEs). The modified carbon electrodes were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Results indicated that Fc-ECG/SPE sensor showed enhanced current response and a lower overpotential than Fc(Cys)2/SPE sensor for nitrite detection. Optimal operating conditions were estimated for nitrite detection by DPV. The concentration of nitrite showed a good linear relationship with the current response in the range of 1.0⁻50 µmol·L-1 and with 0.3 µmol·L-1 as the concentration for limit of detection. There were no interferences from most common ions. The development of this electrochemical sensor was used for nitrite detection in pickled juice with a R.S.D. lower than 2.1% and average recovery lower than 101.5%, which indicated that disposable electrochemical sensor system can be applied for rapid and precise nitrite detection in foods.

Irradiation stents vs. conventional metal stents for unresectable malignant biliary obstruction: A multicenter trial.

BACKGROUND & AIMS: Placement of an irradiation stent has been demonstrated to offer longer patency and survival than an uncovered self-expandable metallic stent (SEMS) in patients with unresectable malignant biliary obstruction (MBO). We aim to further assess the efficacy of an irradiation stent compared to an uncovered SEMS in those patients. METHODS: We performed a randomized, open-label trial of participants with unresectable MBO at 20 centers in China. A total of 328 participants were allocated in parallel to the irradiation stent group (ISG) or the uncovered SEMS group (USG). Endpoints included stent patency (primary), technical success, relief of jaundice, overall survival, and complications. RESULTS: The first quartile stent patency time (when 25% of the patients experienced stent restenosis) was 212 days for the ISG and 104 days for the USG. Irradiation stents were significantly associated with a decrease in the rate of stent restenosis (9% vs. 15% at 90 days; 16% vs. 27% at 180 days; 21% vs. 33% at 360 days; p = 0.010). Patients in the ISG obtained longer survival time (median 202 days vs. 140 days; p = 0.020). No significant results were observed in technical success rate (93% vs. 95%; p = 0.499), relief of jaundice (85% vs. 80%; p = 0.308), and the incidence of grade 3 and 4 complications (8.5% vs. 7.9%; p = 0.841). CONCLUSIONS: Insertion of irradiation stents instead of uncovered SEMS could improve patency and overall survival in patients with unresectable MBO. LAY SUMMARY: For patients with unresectable malignant biliary obstruction (MBO), placement of a self-expandable metallic stent (SEMS) is a recommended palliative modality to relieve pruritus, cholangitis, pain, and jaundice. However, restenosis is a main pitfall after stent placement. Data from this first multicenter randomized controlled trial showed that insertion of an irradiation stent provided longer patency and better survival than a conventional metal stent. ClinicalTrials.gov ID: NCT02001779.

Metal-Crown Ether-Porphyrin Decorated Gold Nanoparticles as High Sensitive Raman Ion Probe.

A kind of gold nanoparticles modified with metal crown ether porphyrin (GNPs-CP) was synthesized and characterized. The surface of the resulting gold particles was partially covered by metal crown ether porphyrin molecules through strong covalent Au-S bond. Based on the coupling effect of metal porphyrin and crown ether, the resulting composite gold nanoparticles can serve as a kind of ion probe. Raman and UV-Vis spectra were utilized to evaluate the ion recognition of the system, both of which changed dramatically when meeting metal ion corresponding to ligand of crown ether. Compared with UV-Vis spectra, Raman spectra of the composites are more sensitive and the limit of detection (LOD) can reach 1 × 10-8 g/mL. The study provides a candidate with higher sensitivity to replace current UV-Vis spectrum based evaluation tool for ion recognition.

Selective Reduction of Nitro Group in Aryl Halides Catalyzed by Silver Nanoparticles Modified with ß-CD.

In this paper, we first report the selective reduction of nitro group in aryl halides catalyzed by silver nanoparticles modified with ß-CD. Taking advantage of hydrophobic lumen and donor-acceptor behavior of ß-CD, the halogenated alkyl groups on the aromatic ring can be enveloped in the inner cavity that thereby inhibits the reduction of the halogen. For validating the mechanism proposed by us, different silver nanoparticles were applied in parallel experiments. In our experiments, UV-vis spectra and NMR spectra were used to characterize the selectivity. This strategy represents an outstanding improvement on the synthesis of halogenated aromatic amines in comparison with the traditional route, and greatly expands the application of silver nanoparticles in catalytic field.

Green Synthesis of Silver Nanoparticles Decorated by Fe3O4/GO with Enhanced Catalytic Activity.

We report a simple and green approach to synthesize stable water-dispersible silver nanoparticles decorated by magnetic Fe3O4 and graphene oxide (GO). These results of UV-Vis spectra, along with TEM and SEM indicated that the water-dispersible silver nanoparticles had cluster flat structure and retained the optical properties of the original silver particle. Combining the advantages of Fe3O4 and GO, the composite nanoparticles showed enhanced catalytic activity with good recycling utilization rate by magnetic separation.

Gold Nanoparticles Prepared by ß-CD and Dispersion Behavior in Oil/Water Mixed System.

In this paper, we report a green and controllable synthetic method of gold nanoparticles (AuNPs) by directly ß-CD reduction under mild conditions. Analysis of UV-vis spectra, along with TEM was applied to study the effects of experimental parameters on morphologies of the gold nanoparticles. The corresponding formation mechanism of the nanoparticles was evaluated by redox potential. In particular, compared with the traditional method of sodium citrate or ascorbic reduction, this method can facilely realize multi-dimensional regulation. On this basis, we further studied the dispersion behavior of the as-prepared gold nanoparticles in oil/water mixed system that would provide a possible strategy for optical sensor.