Influence of Donor Skeleton on Intramolecular Electron Transfer Amount for Efficient Perovskite Solar Cells.

The passivation of the defects derived from rapid-crystallization with electron-donating molecules is always a prerequisite to obtain desirable perovskite films for efficient and stable solar cells, thus, the in-depth understanding on the correlations between molecular structure and passivation capacity is of great importance for screening passivators. Here, we introduce the double-ended amide molecule into perovskite precursor solution to modulate crystallization process and passivate defects. By regulating the intermediate bridging skeletons with alkyl, alkenyl and benzene groups, the results show the passivation strength highly depends on the spin-state electronic structure that serves as an intrinsic descriptor to determine the intramolecular charge distribution by controlling orbital electron transfer from the donor segment to acceptor segment. Upon careful optimization, the benzene-bridged amide molecule demonstrates superior efficacy on improving perovskite film quality. As a physical proof-of-concept, the carbon-based, all-inorganic CsPbI2Br solar cell delivers a significantly increased efficiency of 15.51% with a remarkably improved stability. Based on the same principle, a champion efficiency of 24.20% is further obtained on the inverted (Cs0.05MA0.05FA0.9)Pb(I0.93Br0.07)3 solar cell. These findings provide new fundamental insights into the influence of spin-state modulation on effective perovskite solar cells.

Responses of keratinocytes to Trichophyton mentagrophyte infection based on whole transcriptome analysis.

BACKGROUND: Dermatophytosis is an intractable superficial mycosis in humans and animals mainly caused by Trichophyton mentagrophytes (T. mentagrophytes), with a global prevalence of about 20%. Keratinocytes are the most abundant participants in skin immunity, and they also play a role in the first-line defence against T. mentagrophytes. However, no studies of keratinocyte responses against T. mentagrophytes infection based on the whole transcriptome have been reported. OBJECTIVES: Here, we systematically analysed changes in keratinocytes infected with T. mentagrophytes using whole transcriptome sequencing technology. METHODS: The phenotypic changes in keratinocytes after infection with 1 × 105 conidia/mL T. mentagrophytes were observed by light microscopy, scanning electron microscopy, transmission electron microscopy and terminal deoxynucleotidyl transferase dUTP nick end labeling. RNA-sequencing (RNA-seq), small RNA-seq technology and related bioinformatics methods were used to systematically analyse the whole transcriptome changes in keratinocytes upon T. mentagrophytes stimulation. RESULTS: We found that T. mentagrophytes infection caused morphological changes, membrane damage, the formation of irregular organelles and keratinocyte apoptosis. A total of 204 differentially expressed (DE) circular RNAs (circRNAs), 868 DE long noncoding RNAs (lncRNAs), 2973 DE mRNAs and 209 DE micro RNAs (miRNAs) were identified between noninfected and T. mentagrophytes-infected keratinocytes. The expression level of selected RNAs was validated by quantitative real-time polymerase chain reaction (qRT-PCR). Functional enrichment analysis revealed that the parental genes of DE circRNAs were related to cell response, cell death and establishment of the skin barrier. Genes targeted by miRNA were involved in regulating the initiation of the immune response. Based on the expression level of circRNAs, lncRNAs, mRNAs and miRNAs, circRNA-miRNA-mRNA competing endogenous (ceRNA) networks comprised of 159 DE miRNAs, 141 DE circRNAs and 2307 DE mRNAs, and lncRNA-miRNA-mRNA ceRNA networks comprised of 790 DE lncRNAs, 190 DE miRNAs and 2663 DE mRNAs were constructed. The reliability of two selected ceRNA networks was verified using qRT-PCR. Further functional enrichment analysis revealed that the DE mRNAs interacting with circRNAs and lncRNAs in the ceRNA network mainly participated in fungal recognition, inflammation, the innate immune response and the death of keratinocytes. CONCLUSIONS: Our findings might provide new evidence on the pathogenesis of T. mentagrophytes-induced dermatophytosis, which is essential for identifying new therapeutic targets for dermatophytosis treatment.

DCT-Net: An effective method to diagnose retinal tears from B-scan ultrasound images.

Retinal tears (RTs) are usually detected by B-scan ultrasound images, particularly for individuals with complex eye conditions. However, traditional manual techniques for reading ultrasound images have the potential to overlook or inaccurately diagnose conditions. Thus, the development of rapid and accurate approaches for the diagnosis of an RT is highly important and urgent. The present study introduces a novel hybrid deep-learning model called DCT-Net to enable the automatic and precise diagnosis of RTs. The implemented model utilizes a vision transformer as the backbone and feature extractor. Additionally, in order to accommodate the edge characteristics of the lesion areas, a novel module called the residual deformable convolution has been incorporated. Furthermore, normalization is employed to mitigate the issue of overfitting and, a Softmax layer has been included to achieve the final classification following the acquisition of the global and local representations. The study was conducted by using both our proprietary dataset and a publicly available dataset. In addition, interpretability of the trained model was assessed by generating attention maps using the attention rollout approach. On the private dataset, the model demonstrated a high level of performance, with an accuracy of 97.78%, precision of 97.34%, recall rate of 97.13%, and an F1 score of 0.9682. On the other hand, the model developed by using the public funds image dataset demonstrated an accuracy of 83.82%, a sensitivity of 82.69% and a specificity of 82.40%. The findings, therefore present a novel framework for the diagnosis of RTs that is characterized by a high degree of efficiency, accuracy and interpretability. Accordingly, the technology exhibits considerable promise and has the potential to serve as a reliable tool for ophthalmologists.

Modulating Electronic Structure by Etching Strategy to Construct NiSe2 /Ni0.85 Se Heterostructure for Urea-Assisted Hydrogen Evolution Reaction.

Exploring and developing novel strategies for constructing heterostructure electrocatalysts is still challenging for water electrolysis. Herein, a creative etching treatment strategy is adopted to construct NiSe2 /Ni0.85 Se heterostructure. The rich heterointerfaces between NiSe2 and Ni0.85 Se emerge strong electronic interaction, which easily induces the electron transfer from NiSe2 to Ni0.85 Se, and tunes the charge-state of NiSe2 and Ni0.85 Se. In the NiSe2 /Ni0.85 Se heterojunction nanomaterial, the higher charge-state Ni0.85 Se is capable of affording partial electrons to combine with hydrogen protons, inducing the rapid formation of H2 molecule. Accordingly, the lower charge-state NiSe2 in the NiSe2 /Ni0.85 Se heterojunction nanomaterial is more easily oxidized into high valence state Ni3+ during the oxygen evolution reaction (OER) process, which is beneficial to accelerate the mass/charge transfer and enhance the electrocatalytic activities towards OER. Theoretical calculations indicate that the heterointerfaces are conducive to modulating the electronic structure and optimizing the adsorption energy toward intermediate H* during the hydrogen evolution reaction (HER) process, leading to superior electrocatalytic activities. To expand the application of the NiSe2 /Ni0.85 Se-2h electrocatalyst, urea is served as the adjuvant to proceed with the energy-saving hydrogen production and pollutant degradation, and it is proven to be a brilliant strategy.

In situ Hg2+ improved the peroxidase-like activity and triggered "ON" the oxidase-like activity of yolk-shell Co3S4 microspheres for the detection of Hg2.

Exploring highly active nanozymes is an important task to realize the real-time detection of some heavy metal ions in water. In this work, yolk-shell Co3S4 microspheres have been verified to possess excellent peroxidase-like activity, which can be further improved by adding Hg2+. Very interestingly, Hg2+ can trigger "ON" the oxidase-like activity of Co3S4 microspheres. The dual peroxidase-/oxidase-like activity of the yolk-shell Co3S4 microspheres is evaluated by using the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB). Furthermore, comprehensive studies verify that the enhanced peroxidase-like activity, together with the "ON" oxidase-like activity of the yolk-shell Co3S4 microspheres, is attributed to the in situ generation of HgS on the surface of Co3S4 microspheres and then the release of more active sites. Importantly, the in situ generated HgS on the surface of Co3S4 microspheres can form a heterojunction, which also accelerates the catalytic process. During the catalytic reaction, some active species (O2- and h+) can be detected by ESR. Thus, a colorimetric sensing platform based on Hg2+-triggered signal amplification has been successfully constructed, which can be validated by the detection of Hg2+ residue in environmental water.

Engineering Lattice Planes of NiCo-LDH Ultrathin Sheets for Boosting Methanol/Ethanol Oxidation Performance.

Alcohol oxidation reactions are known to be significant in the advancement of sustainable, renewable energy sources. Searching for catalytic materials with powerful, reliable, and economic performance is of great importance. Due to their excellent intrinsic performance, outstanding stability, and inexpensiveness, ultrathin layered double hydroxides (LDHs) are considered to be competitive electrocatalysts. However, the electrocatalytic property of ultrathin LDHs is still confined by the predominant exposure of the (003) basal plane. Hence, we have engineered active edge facets in ultrathin NiCo-LDHs, which possess abundant oxygen vacancies (VO), by a facile one-step strategy. Experimental results show that NiCo-LDH-E synthesized in ethanol demonstrates an ultrathin structure, rich oxygen vacancies, and more active facets, exhibiting a higher electrochemical active area of 3.25 cm2, which is 1.18 times that of NiCo-LDH-W (2.75 cm2). In addition, the current density of NiCo-LDH-E in methanol and ethanol oxidation reactions could reach 159.5 and 136.3 mA cm-2, which are 2.8 and 1.7 times that of NiCo-LDH-W, respectively.

N,N-dicarboxymethyl Perylene-diimide-modified CdV2O6 Nanorods for Colorimetric Sensing of H2O2 and Pyrogallol.

The peroxidase-like activity of CdV2O6 nanorods has been considerably improved by modification with N, N-dicarboxymethyl perylene-diimide (PDI) as a photosensitizer. The peroxidase-like behaviors are evaluated by virtue of the colorless chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB), which is fast changed into blue oxTMB in the presence of H2O2 in only 90 s. PDI-CdV2O6 exhibits high stability at elevated temperatures and PDI-CdV2O6 retains more than 70% of its catalytic activity over a wide range of 15 to 60 °C. The catalytic mechanism of PDI-CdV2O6 is ascribed to the synergistic interaction between PDI and CdV2O6 and the generation of •O2- radicals. Based on the enhanced peroxidase-like activity of PDI-CdV2O6, a selective colorimetric sensor has been constructed for H2O2 and pyrogallol (PG) with detection limits of 36.5 µM and 0.179 µM, respectively. The feasibility of the proposed sensing platform has been validated by detecting H2O2 in milk and pyrogallol in tap water.

Enhancement of photoelectrocatalytic performance of copper cobaltate nanoflowers modified with 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin for methanol oxidation under light.

With the continuously increasing global energy demand, there is an urgent requirement to find efficient methanol oxidation reaction (MOR) catalysts that can replace precious metals. In this work, we have elaborately integrated 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin (H2TCPP) with copper cobaltate (CuCo2O4), which possesses efficient separation of photogenerated charges and increased active sites. The mass activity of H2TCPP/CuCo2O4 (534.75 mA mg-1) toward MOR is higher than that of pure CuCo2O4 (291.75 mA mg-1) under light. In addition, H2TCPP/CuCo2O4 can catalyze the oxidation of other alcohols, such as ethanol, ethanediol, isopropanol, and glycerol. This study demonstrates that it is feasible to enhance the MOR activity by the modification of bimetallic transition metal oxides with porphyrins.

Z-scheme CuO/Fe3O4/GO heterojunction photocatalyst: Enhanced photocatalytic performance for elimination of tetracycline.

CuO/Fe3O4/GO, as a Z-scheme heterojunction catalyst, was successfully synthesized and used as a photocatalyst for removing tetracycline from aqueous solution. The CuO/Fe3O4/GO heterogeneous catalyst combines the narrow bandgap semiconductor CuO, oxygen vacancies of Fe3O4, and oxygen-containing reaction sites of GO. Without the addition of activators (persulfate or H2O2), the photocatalytic performance on decomposing tetracycline is very excellent. Compared with GO, Fe3O4, and CuO, CuO/Fe3O4/GO exhibits superior photocatalytic performance. Under visible light radiation, CuO/Fe3O4/GO generates h+ and ⋅O2-, which are the mainly responsible active groups for TC degradation. The effects of various pH, catalysts, and reuse on the degradation performance are evaluated, and the optimal conditions for CuO/Fe3O4/GO removal of tetracycline are obtained at pH 7, catalyst dosage 20 mg⋅L-1, TC at a concentration of 30 mg/L, nearly 97.3% of tetracycline is decomposed. This study has great potential in the treatment of wastewater containing various antibiotics.

Unveiling the influence of 5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin on the photogenerated charge behavior and photoelectrochemical water oxidation of hematite photoanode.

Coupling porphyrins with semiconductors is demonstrated as one of effective means to facilitate the separation of photogenerated charge in dye-sensitized solar cells as well as photocatalytic hydrogen production. However, there are limited reports about exploring the effect of porphyrin on the behavior of photogenerated charges and photoelectrochemical (PEC) water oxidation performance. Herein, we have built a hybrid photoanode containing Ti doped α-Fe2O3 (Ti-Fe2O3), 5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin (H2TCPP) and cobalt phosphate (CoPi) cocatalyst. Because of the appropriate band alignment of Ti-Fe2O3, H2TCPP and CoPi, the photogenerated holes are transferred directionally from Ti-Fe2O3 to CoPi across H2TCPP, which boosts the separation efficiency of CoPi/H2TCPP/Ti-Fe2O3 in turn. Meanwhile, CoPi/H2TCPP/Ti-Fe2O3 possesses higher injection efficiency as well. Under the double guarantee of high separation efficiency and injection efficiency, CoPi/H2TCPP/Ti-Fe2O3 yields an impressive photocurrent density of 1.84 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), which is much higher than that of CoPi/Ti-Fe2O3. This structure design describes an appealing maneuver to facilitate the directed migration of photogenerated charges and then enhance the PEC water oxidation performance.

CeO2/Co3O4@N-doped hollow carbon microspheres with improved peroxidase-like activity for the determination of quercetin.

Nanozymes, as substitutes for natural enzymes, have been used to construct some fast cheap sensing platforms by virtue of the high catalytic activity. Herein, we firstly study the peroxidase-like activity of CeO2/Co3O4@N-doped hollow carbon microspheres as nanozymes. In the presence of H2O2, CeO2/Co3O4@NCH exhibits high peroxidase-like activity evaluated by the catalytic oxidation of the chromogenic substrate, 3,3',5,5'-tetramethylbenzidine (TMB) into a blue oxTMB visually in 1 min. The larger surface area, pore-like structure, and oxygen vacancies contribute to the enhanced peroxidase-like activity of CeO2/Co3O4@NCH. The active species •O2- is detected during the catalytic process. Thus, based on the excellent peroxidase-like activity of CeO2/Co3O4@NCH, a facile and effective biosensor is fabricated for sensitive and selective determination of H2O2 and quercetin, respectively. CeO2/Co3O4@NCH shows high affinity towards H2O2 (Km = 4.001 mM) and TMB (Km = 0.086 mM). The detection limit of H2O2 and quercetin is as low as 0.086 mM and 1.19 µM (3σ/slope), respectively. This work remarkably extends the utilization of CeO2/Co3O4@NCH in designing a colorimetric sensing platform related to biosensing, food, and environmental monitoring. A fast colorimetric sensing platform for quercetin based on the excellent peroxidase-like activity of CeO2/Co3O4@NCH.

Biomass activated carbon-derived imprinted polymer with multi-boronic acid sites for selective capture of glycoprotein.

Glycoproteins play crucial roles in many biological events such as protein folding, information transmission, nerve conduction, and molecular recognition. Some glycoproteins serve as disease biomarkers in clinical settings. However, selective detection of glycoprotein often faces great challenges, owing to its low abundance in complex biological samples. In this case, develop a highly sensitive and selective approach for glycoprotein detection is urgently needed. Molecularly imprinted polymers (MIPs) have proved to be an ideal absorbent material in detection and separation science. Herein, a novel biomass activated carbon-derived imprinted polymer (BAC@PEI/PBA/MIPs) was fabricated for selective recognition of glycoprotein. The as-prepared BAC@PEI/PBA/MIPs was synthesized using waste tea derived carbon as matrix, albumin chicken egg (OVA) as template, and dopamine as functional monomer. Branched polyethyleneimine (PEI) was covalently bonded on the BAC surface to increase the number of boronic acid moieties. Benefiting from the self-polymerization of dopamine and multi-boronic acid sites, a great number of recognition sites were presented under mild conditions. The static adsorption experiment showed that the BAC@PEI/PBA/MIPs exhibited a high binding capacity of 196.2 mg/g, rapid adsorption dynamics of 40 min, excellent selectivity and satisfactory reusability for OVA. Furthermore, the practicability of BAC@PEI/PBA/MIPs was verified by isolation of OVA from egg white. The good binding performance and facile preparation process make BAC@PEI/PBA/MIPs attractive for glycoprotein recognition, indicating its potential applications in biomedical research and clinical diagnostics.

5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin-functionalized urchin-like CuCo2O4 as an excellent artificial nanozyme for determination of dopamine.

Urchin-like peroxidase mimics 5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin-functionalized CuCo2O4 nanospheres (Por-CuCo2O4) has been fabricated as an excellent visual biosensor. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) have been employed to characterize the composition, morphologies, and elemental analysis of the as-synthesized Por-CuCo2O4. The catalytic activity of Por-CuCo2O4 was evaluated by the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) with the aid of H2O2, which exhibited a visual blue change with an absorption maximum at 652 nm for only 10 s. The peroxidase-like behaviors of Por-CuCo2O4 conformed to the Michaelis-Menten equation. Electrochemistry, radical scavenger, and fluorescence probe experiments verified that electron transfer, •O2- radicals, and holes (h+) are the important factors during the catalytic oxidation of TMB. Based on the inhibition of dopamine (DA) on TMB oxidation, the Por-CuCo2O4-based colorimetric biosensor has been successfully constructed for sensitive determination of DA witha detection limit (LOD) of 0.94 µΜ. In addition, colorimetry was validated to detect DA in serum samples with high sensitivity and good selectivity. 5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin-functionalized urchin-like CuCo2O4 (Por-CuCo2O4) with excellent peroxidase activity, ascribed to the synergistic effect between •O2- radicals and holes (h+). A fast colorimetric sensor on the basis of Por-CuCo2O4 has been constructed to quantitatively determine dopamine concentration in human serums.

A Polymer-Based Matrix for Effective SALDI Analysis of Lipids.

Surface-assisted laser desorption/ionization (SALDI) has become an attractive branch of matrix-assisted laser desorption/ionization (MALDI) and has been successfully applied for the detection of small molecules due to the lack of the interference of matrix. Herein, the low-cost and highly accessible polyvinylidene fluoride (PVDF) was modified using a facile alkali treatment and investigated as a SALDI matrix. The modified PVDF has a strong optical absorption and can be applied as a dual-mode substrate for both SALDI MS and SALDI imaging analysis. Modified PVDF powder showed superior performance in SALDI MS analysis of lipids, with good reproducibility, high sensitivity, and low background interference, especially for triacylglycerols (TAGs) and fatty acids. Additionally, the lipids in raw and extracted serum were both successfully determined with modified PVDF powder. A modified PVDF membrane (m-PVDF-m) showed excellent ability in lipids imaging in tissues due to its flat surface, mass signal enhancement, and elimination of matrix coating. The distribution of several TAGs and cholesteryl esters on mouse kidney section was presented by SALDI imaging directly on m-PVDF-m. These results demonstrated that modified PVDF materials presented exciting opportunities as matrices for the first time in SALDI MS acquisition and SALDI imaging.

Porphyrin functionalized Co(OH)2/GO nanocomposites as an excellent peroxidase mimic for colorimetric biosensing.

5,10,15,20-Tetrakis(4-carboxyl phenyl)porphyrin (Por) modified Co(OH)2 deposited on the surface of GO nanocomposites (Por/Co(OH)2/GO) were prepared and characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and XRD. For the first time, H2TCPP/Co(OH)2/GO is found to have enhanced peroxidase-like activity and catalyze the oxidation of the substrate 3,3,5,5-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2). Notably, the colorless TMB rapidly transformed into blue oxTMB in just 60 s, which was easily observed visually. The catalytic kinetics of H2TCPP/Co(OH)2/GO is in accord with the Michaelis-Menten equation. The catalytic mechanism of H2TCPP/Co(OH)2/GO nanocomposites is attributed to hydroxyl radicals (˙OH), due to decomposition of H2O2, which is verified by using terephthalic acid as a fluorescent probe. What's more, H2O2 can be detected in a wide linear detection range from 5 to 35 mM with a detection limit of 0.385 mM. Furthermore, based on the excellent peroxidase-like activity of H2TCPP/Co(OH)2/GO, a colorimetric sensor is established to sensitively detect glutathione (GSH) in a linear range from 10 to 300 µM with a low detection limit of 9.5 µM.

Protein recognition by polydopamine-based molecularly imprinted hollow spheres.

A facile method to prepare hollow molecularly imprinted polymers (HMIPs) for specific recognition of horseradish peroxidase (HRP) from biological samples was proposed in this paper. The HMIPs was prepared using silica nanoparticles as the sacrificial matrix and dopamine as functional monomer. The thickness of polydopamine shells can be easily modulated by tuning the mass ratio of silica matrix and dopamine. The polymerization conditions and recognition behaviors of the HMIPs were investigated systematically. The results suggested that the hollow structure endowed the HMIPs with fast adsorption kinetics of 25 min, high binding capacity of 172.1 mg/g, and reusability of no less than four adsorption-regeneration cycles without apparent deterioration. Meanwhile, excellent binding specificity towards HRP was presented in the selectivity studies. Moreover, enriching of HRP from human serum sample by the obtained HMIPs was conducted. The HMIPs displayed satisfactory binding specificity to HRP, in spite of the complex composition of the human serum.

A close-packed imprinted colloidal array for naked-eye detection of glycoproteins under physiological pH.

According to the combination of colloidal crystals and molecular imprinting techniques, a novel close-packed imprinted colloidal array (CPICA) for naked-eye horseradish peroxidase (HRP) detection at physiological pH was proposed. The CPICA was fabricated by self-assemble of monodispersed HRP imprinted particles. The HRP imprinted particles were prepared based on surface imprinting technique and immobilized template strategy using 2,4-difluoro-3-formylphenylboronic acid (DFFPBA) as functional monomer which allowed the material binding of HRP at physiological pH (denoted as SiO2@DFFPBA/MIPs). The adsorption capacity of the SiO2@DFFPBA/MIPs for HRP was 1.16 µmol/g, and reached saturated adsorption within 25 min. The limit of detection (LOD) of the CPICA was 3.0 × 10-13 mol/mL. In addition, the adsorption of HRP on the CPICA could be directly transferred into visible color changes and readable optical signals through the reflection peak shifts. The structure color of the CPICA changed from brilliant blue to dark red with an maximum red shift of 87 nm when the HRP concentration increased from 2.5 to 20.0 µmol/L. Moreover, the CPICA could be used to detect HRP from human serum sample, which demonstrated the promising application prospects in colorimetric sensors.

Quantitative analysis of free fatty acids in gout by disposable paper-array plate based MALDI MS.

The quantitative determination of small molecules by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI TOF MS) was always challenging, due to low sensitivity and interferences of matrix and other contaminants on sample plates. Here we report a disposable paper-array (PA) plate in MALDI TOF MS analysis for quantitative analysis of serum free fatty acids (FFAs) with less interference and higher sensitivity, compared with conventional stainless steel (SS) plate. The disposable PA plate was low cost and environmentally friendly. In particular, it was more sensitive in FFAs detection with ~8-34-fold sensitivity increase for eight FFAs as compared to SS plate. Eight serum FFAs in gout patients were investigated using this disposable PA plate. The quantitative results showed good linearity of all eight FFAs between 0.1 and 2.5 mM with correlation coefficients between 0.994 and 0.999 and limits of detection (LODs) between 8.6 and 104.2 µM. Mann-Whitney U test, principal component analysis (PCA) and random forest categorizer allowed the clear separation of gout patients from healthy controls, according to eight FFAs levels in serum detected by disposable PA plate based MALDI TOF MS.

Mitochondria-mediated apoptosis was induced by oleuropein in H1299 cells involving activation of p38 MAP kinase.

Lung cancer is the main health threat in the world. Recently, oleuropein has been reported to have potent antioxidant and anticancer activities. However, the antitumor effects of oleuropein on H1299 cells are not well understood. Therefore, the purpose of this paper is tantamount to explore the effects of oleuropein on H1299 cells and its underlying mechanism that may be involved. Oleuropein treatment in H1299 cells resulted in cell cycle distribution at G2 /M arrest and apoptosis in a dose-dependent manner. Mitochondria-mediated apoptosis was verified by the increase in Bax/Bcl-2 ratio, release of cytochrome c, and activation of caspase-3 on oleuropein-induced H1299 cells. In addition, our data also demonstrated that the p38 mitogen-activated protein kinase (MAPK) signaling pathway has a critical role in oleuropein-induced apoptosis. Moreover, we used transcriptome analysis to identify differentially expressed genes (DEGs) in H1299 cells by oleuropein and SB203580 treatment. Many DEGs were annotated to metabolic pathways, cell cycle, pathways in cancer, MAPK signaling pathway by Kyoto Encyclopedia of Genes and Genomes and Gene ontology enrichment methods. Network and expression analysis found that DEGs, including RPS6A5, GADD45A, and MKP, play a key role in the p38 MAPK signaling pathway. In H1299 cells, oleuropein resulted in the expression of numerous genes related to cell signaling, metabolism pathway and directly associated with apoptosis. These results illustrated that oleuropein-induced apoptosis via mitochondrial apoptotic cascade was activated by the p38 MAPK signaling pathway in H1299 cells. Thus, oleuropein as a natural compound and therapeutic drug has potential application value in the treatment of lung cancer.

FeNC/MXene hybrid nanosheet as an efficient electrocatalyst for oxygen reduction reaction.

The iron-nitrogen-carbon (FeNC) catalyst, as a highly active and stable non-precious metal catalyst, has emerged as one of the most promising alternatives to replace the platinum catalyst for oxygen reduction reaction (ORR). Herein, a novel FeNC/MXene hybrid nanosheet was, for the first time, explored via pyrolysis of an iron-ligand complex and MXene nanosheets. The structure and morphology characterizations reveal that a thin and rugged FeNC coating was closely attached on the surface of MXene, forming a hybrid nanosheet structure with an excellent conductive substrate and many electrocatalytic active sites on the substrate. The electrochemical measurements disclose that the FeNC/MXene hybrid nanosheet exhibited a remarkable electrocatalytic performance, with a 25 mV higher half-wave potential (0.814 V versus RHE) than the Pt/C counterpart. More importantly, this hybrid presented a superb durability, with only 2.6% decay after a 20 000 s continuous test, much better than the 15.8% degradation for Pt/C. This work not only demonstrates the promising performance of the FeNC/MXene hybrid nanosheet for ORR, but more importantly provides new insight into the rational design of non-noble-metal catalysts using an MXene support.