Nafion-Immobilized Functionalized MWCNT-based Electrochemical Immunosensor for Aflatoxin B1 Detection.

The ubiquitous aflatoxin B1 (AFB1) contamination in foods and other complex matrices has brought great challenges for onsite monitoring. In this study, an ultrasensitive Nafion-immobilized functionalized multiwalled carbon nanotube (MWCNT)-based electrochemical (EC) immunosensor was developed for trace AFB1 detection. The introduced Nafion film could steadily stabilize functionalized MWCNTs with uniform distribution and tiling on the surface of a Au electrode. Functionalized MWCNTs with a large specific surface area, numerous active sites to couple with abundant anti-AFB1 monoclonal antibodies (mAbs), and high conductivity served as the signal amplifier for remarkably enhancing the sensing performance of the immunosensor. In the presence of AFB1, it was specifically captured by mAbs to reduce the amplified current signals, which were recorded by differential pulse voltammetry for the accurate quantitation of AFB1. Because of the synergistic effects of Nafion on the stabilization of functionalized MWCNTs as signal enhancers, the developed EC immunosensor exhibited an extremely high selectivity, excellent sensitivity with a limit of detection as low as 0.021 ng/mL, and a wide dynamic range of 0.05-100 ng/mL, besides fascinating merits of easy construction, low cost, good stability in 7 days, and good reusability. The anti-interference ability of the immunosensor was verified against three other mycotoxins, and the practicability and accuracy were confirmed by measuring AFB1 in fortified malt, lotus seed, and hirudo samples with a satisfactory recovery of 92.08-104.62%. This novel immunosensing platform could be extended to detect more mycotoxins in complex matrices to ensure food safety.

Shizao decoction for cirrhotic ascites: assessing potential targets based on network analysis combined with pharmacokinetics and metabolomics.

Introduction: Shizao decoction (SZD) is a traditional Chinese medicine decoction that has therapeutic effects on cirrhotic ascites (CAS). Because of the unclear treatment mechanism, in the current study, the anti-CAS activity of SZD and molecular mechanisms were analyzed by network analysis combined with pharmacokinetics and metabolomics. Methods: Firstly, we assessed the anti-CAS efficacy of SZD by hematoxylin-eosin (H&E), liver function tests, NO and ET-1 levels, and portal venous pressure. Secondly, network analysis was applied to dig out the metabolites, targets, and pathways related to SZD and CAS. Then, the pharmacokinetics of the pharmacokinetically relevant metabolites (PRM) were analyzed. Thirdly, the serum and urine metabolic biomarkers of rats with CAS were identified using metabolomics by comparing them with the SZD treatment group. In addition, MetaboAnalyst was utilized to conduct metabolic pathway analysis. Finally, the correlation analysis established a dynamic connection between absorbed PRM from SZD and CAS-associated endogenous metabolites. Results: Pharmacodynamic analysis indicated that SZD effectively mitigated liver injury symptoms by ameliorating inflammatory cell infiltration in CAS rats. The network analysis results indicated that twelve RPM contribute to the therapeutic efficacy of SZD against CAS; the key signaling pathways involved might be hepatitis B and PI3K-Akt. Pharmacokinetics results showed that the 12 RPM were efficiently absorbed into rat plasma, ensuring desirable bioavailability. The metabolomic analysis yielded 21 and 23 significantly distinct metabolites from the serum and urine, respectively. The 12 bioavailable SZD-PRM, such as luteolin, apigenin, and rutin, may be associated with various CAS-altered metabolites related to tryptophan metabolism, alpha-linolenic acid metabolism, glycine metabolism, etc. Discussion: A novel paradigm was provided in this study to identify the potential mechanisms of pharmacological effects derived from a traditional Chinese medicine decoction.

A new multi-template molecularly imprinted polymer for separation and purification of dioscin, protodioscin, and diosgenin from purple yam.

Saponin is an essential natural compound in purple yams with high nutritional and medicinal value. In this work, a multitemplate molecule-imprinted polymer (MMIP) was synthesized with dioscin, protodioscin, and diosgenin templates. The MMIPs were characterized with scanning electron microscopy, thermogravimetric analysis, Brunauer-Emmett-Teller (BET) adsorption, and Fourier transform infrared spectroscopy. The efficacy of the MMIPs was assessed with static, dynamic, selective adsorption, desorption, and reusability experiments. The three saponins were selectively extracted and determined by MMIP-high-performance liquid chromatography. The polymer morphology was regular and spherical. The amount of the MMIP adsorbed was 74.825 mg/g, and the imprinting factor was 2.1. The MMIP adsorbed the three saponins from purple yam extract, with recovery rates of 95.5-103.43 % and desorption rates of 85 %-98 %. In addition, the MMIPs were reused at least six times. These results demonstrated that the MMIPs efficiently and selectively extracted dioscin, protodioscin, and diosgenin from food matrices at high rates.

Bifunctional 3D POM-based coordination polymers for improved pseudocapacitance and catalytic oxidation performance.

Developing novel high-efficiency supercapacitors as energy storage devices to solve the energy crisis is of vital significance. Meanwhile, designing highly active and selective oxidation catalysts for various sulfides is desirable but still a big challenge. To work out these problems, three novel 3D POM-based coordination polymers (POMCPs), formulated as [{Ag6(pytz)4}{SiMo12O40}] (1), [{Cu3(pytz)4}{SiMo12O40}]·5.5H2O (2) and [{Cu6(pytz)6}{SiMo12O40}]·2H2O (3) (pytz = 4-(5-(4-pyridyl)-1H-tetrazole)), are successfully prepared via a one-step synthetic strategy by changing different temperatures under hydrothermal or solvothermal conditions. In compounds 1 and 2, {SiMo12}, as 9-capped and 2-capped polyoxoanions, are engaged among the 2D Ag/Cu-organic sheets to generate the novel 3D POM-based coordination polymers. In addition, 1D Cu-organic chains are combined with 3-capped {SiMo12} polyoxoanions to construct 2D POM-based coordination polymers in 3. To our delight, as electrode materials for supercapacitors, the three compounds exhibit excellent specific capacitances of 261.76 F g-1, 248.82 F g-1 and 156.47 F g-1 at 0.5 A g-1, respectively. Besides, they can effectively and selectively catalyze the oxidation of various sulfides to sulfoxides.

Molecularly imprinted polymers based on calcined rape pollen and deep eutectic solvents for efficient sinapic acid extraction from rapeseed meal extract.

Substances that possess hierarchical and interconnected porous features are ideal choices for acting as skeletons to synthesize surface molecularly imprinted polymers (MIPs). In this work, rape pollen, a waste of biological resources, was calcined and a porous mesh material with a high specific surface area was obtained. The cellular material was adopted as a supporting skeleton to synthesize high-performance MIPs (CRPD-MIPs). The CRPD-MIPs presented an ultrathin imprinted layered structure, with an enhanced adsorption capacity for sinapic acid (154 mg g-1) relative to the non-imprinted polymers. The CRPD-MIPs also exhibited good selectivity (IF = 3.24) and a fast kinetic adsorption equilibrium (60 min). This method exhibited a good linear relationship (R2 = 0.9918) from 0.9440 to 29.26 µg mL-1, and the relative recoveries were 87.1-92.3%. The proposed CRPD-MIPs based on hierarchical and interconnected porous calcined rape pollen may be a valid program for the selective extraction of a particular ingredient from complicated actual samples.

Ultrasensitive electrochemical aptasensor with Nafion-stabilized f-MWCNTs as signal enhancers for OTA detection.

In this study, an ultrasensitive electrochemical (EC) aptasensor with Nafion-stabilized functionalized multi-walled carbon nanotubes (f-MWCNTs) as signal enhancers was established for ochratoxin A (OTA) determination. Herein, f-MWCNTs were prepared through functionalization with nitric acid. The incorporation of Nafion promoted a good dispersion of f-MWCNTs and prevented their leaching on the electrode, making a robust stability of the aptasensor. The Nafion-f-MWCNTs composites were used as the sensing substrates to largely enhance the electroactive surface area and the conductivity of the electrode, realizing a significant signal amplification. Carboxyl groups on the surface of f-MWCNTs readily exposed from Nafion membrane to couple with streptavidin, facilitating the immobilization of biotinylated aptamers to achieve selective recognition towards OTA. When OTA existed, aptamers preferentially combined with it, causing a noticeable decline in the current response. Under optimum conditions, a good linear relationship between the current changes and the logarithm of OTA concentration was observed from 0.005 ng/mL to 10 ng/mL, with a limit of detection low to 1 pg/mL for OTA. The specific, sensitive, and reproducible aptasensor succeeded in application in malt samples, confirming a great promise for more contaminants and providing a universal platform in complex matrices by simply replacing the corresponding aptamers.

Graphene Coated Dielectric Hierarchical Nanostructures for Highly Sensitive Broadband Infrared Sensing.

Broadband infrared (IR) absorption is sought after for wide range of applications. Graphene can support IR plasmonic waves tightly bound to its surface, leading to an intensified near-field. However, the excitation of graphene plasmonic waves usually relies on resonances. Thus, it is still difficult to directly obtain both high near-field intensity and high absorption rate in ultra-broad IR band. Herein, a novel method is proposed to directly realize high near-field intensity in broadband IR band by graphene coated manganous oxide microwires featured hierarchical nanostructures (HNSs-MnO@Gr MWs) both experimentally and theoretically. Both near-field intensity and IR absorption of HNSs-MnO@Gr MWs are enhanced by at least one order of magnitude compared to microwires with smooth surfaces. The results demonstrate that the HNSs-MnO@Gr MWs support vibrational sensing of small organic molecules, covering the whole fingerprint region and function group region. Compared with the graphene-flake-based enhancers, the signal enhancement factors reach a record high of 103 . Furthermore, just a single HNSs-MnO@Gr MW can be constructed to realize sensitively photoresponse with high responsivity (over 3000 V W-1 ) from near-IR to mid-IR. The graphene coated dielectric hierarchical micro/nanoplatform with enhanced near-field intensity is scalable and can harness for potential applications including spectroscopy, optoelectronics, and sensing.

Development of a Nafion-MWCNTs and in-situ generated Au nanopopcorns dual-amplification electrochemical aptasensor for ultrasensitive detection of OTA.

Trace detection of ochratoxin A (OTA) in foods is essential to mitigate risks to human health. Herein, a label-free electrochemical (EC) aptasensor based on dual-signal amplification of Nafion dispersed multi-walled carbon nanotubes (Nafion-MWCNTs) and Au nanopopcorns was developed for ultrasensitive detection of OTA. Nafion solution prevented the leaching of MWCNTs, and the Nafion-MWCNTs modified screen-printed carbon electrode (SPCE) acted as the sensing substrate which facilitated the uniform distribution of the electrodeposited Au nanopopcorns. The in-situ generated Au nanopopcorns could not only load a large amount of aptamers for specific identification of OTA, but also promote the electron transfer of the sensing platform. The incorporation of Nafion-MWCNTs and Au nanopopcorns realized dual-amplification of the aptasensor due to the enhanced conductivity and the increased electroactive surface area of the electrode. The modified electrodes were characterized through scanning electron microscopy, X-ray photoelectron spectroscopy and EC evaluation. Under optimal conditions, the electrochemical impedance spectroscopy (EIS) was measured for the determination of OTA. The as-fabricated Au nanopopcorns/Nafion-MWCNTs impedimetric aptasensor displayed excellent sensitivity with a detection limit as low as 1 pg/mL and a wide linear range of 1 pg/mL-10 ng/mL for OTA. Practical application of the aptasensor in the spiked malt samples achieved satisfactory recoveries of 89.82-95.65 %, which was also successfully verified to detect OTA in eleven batches of actual malt samples collected from the local market. The creative aptasensor is simple, cost-effective, sensitive, and accurate, showing great promise for on-site monitoring of other trace contaminants in foods by simply replacing the aptamers.

Single-Molecule Real-Time Sequencing to Explore the Mycobiome Diversity in Malt.

This study determined the composition of fungal communities and characterized the enriched fungal species in raw and roasted malts via the third-generation PacBio-based full-length single-molecule real-time (SMRT) sequencing of the full-length amplicon of the internal transcribed spacer (ITS) region. In total, one kingdom, six phyla, 23 classes, 56 orders, 120 families, 188 genera, 333 species, and 780 operational taxonomic units (OTUs) were detected with satisfactory sequencing depth and sample size. Wickerhamomyces (56%), Cyberlindnera (15%), Dipodascus (12%), and Candida (6.1%) were characterized as the dominant genera in the raw malts, and Aspergillus (35%), Dipodascus (21%), Wickerhamomyces (11%), and Candida (3.5%) in the roasted malts. Aspergillus proliferans, Aspergillus penicillioides, and Wickerhamomyces anomalus represented the crucial biomarkers causing intergroup differences. Correlation analysis regarding environmental factors indicated that the water activity (aw) of the samples affected the composition of the fungal communities in the malts. In practice, special attention should be paid to the mycotoxin-producing fungi, as well as other fungal genera that are inversely correlated with their growth, to ensure the safe use of malt and its end products. IMPORTANCE Fungal contamination and secondary metabolite accumulation in agricultural products represent a global food safety challenge. Although high-throughput sequencing (HTS) is beneficial for explaining fungal communities, it presents disadvantages, such as short reads, species-level resolution, and uncertain identification. This work represents the first attempt to characterize the fungal community diversity, with a particular focus on mycotoxin-producing fungi, in malt via the third-generation PacBio-based full-length SMRT sequencing of the ITS region, aiming to explore and compare the differences between the fungal communities of raw and roasted malts. The research is beneficial for developing effective biological control and conservation measures, including improving the roasting conditions, monitoring the environmental humidity and aw, and effectively eliminating and degrading fungi in the industry chain according to the diverse fungal communities determined, for the safe use of malts and their end products, such as beers. In addition, the third-generation SMRT sequencing technology allows highly efficient analysis of fungal community diversity in complex matrices, yielding fast, high-resolution long reads at the species level. It can be extended to different research fields, updating modern molecular methodology and bioinformatics databases.

Study on the mechanism of anti-hepatic fibrosis of Glycyrrhiza Uralensis-Salvia miltiorrhiza prescription based on serum and urine metabolomics and network pharmacology.

Hepatic fibrosis (HF) is a kind of chronic epidemic liver disease. Glycyrrhiza Uralensis and Salvia Miltiorrhiza (GUSM), traditional Chinese medicine, has the obvious clinical treatment of liver fibrosis. This study aimed to investigate the mechanisms of GUSM against HF by an integrated strategy combining untargeted metabolomics with network pharmacology. The results showed that GUSM prescription can improve the morphology and structure of liver tissue, inhibit the proliferation of collagen fibers and reducing the inflammatory response of the liver and so on. Endogenous metabolites and HF-related potential biomarkers in serum and urine were detected by ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The metabolic pathways were enriched by MetaboAnalyst. GUSM prescription showed an antifibrotic effect on rats by regulating metabolic pathways, mainly pentose and glucuronate interconversions and arachidonic acid metabolism. Network pharmacology was then applied to find 42 overlapping targets of GUSM-HF. Quercetin was found to be the main active component and STAT3 was the main active target in GUSM prescription. Molecular docking showed high affinities between quercetin and STAT3. Therefore, GUSM has protective effects on HF by regulating the metabolism and different signaling pathways. The work also shows that the metabolomic and network pharmacology methods are promising tools to gain insight into the efficacy and mechanism research of traditional Chinese medicines.

Aptasensors for mycotoxins in foods: Recent advances and future trends.

Mycotoxin contamination in foods has posed serious threat to public health and raised worldwide concern. The development of simple, rapid, facile, and cost-effective methods for mycotoxin detection is of urgent need. Aptamer-based sensors, abbreviated as aptasensors, with excellent recognition capacity to a wide variety of mycotoxins have attracted ever-increasing interest of researchers because of their simple fabrication, rapid response, high sensitivity, low cost, and easy adaptability for in situ measurement. The past few decades have witnessed the rapid advances of aptasensors for mycotoxin detection in foods. Therefore, this review first summarizes the reported aptamer sequences specific for mycotoxins. Then, the recent 5-year advancements in various newly developed aptasensors, which, according to the signal output mode, are divided into electrochemical, optical and photoelectrochemical categories, for mycotoxin detection are comprehensively discussed. A special attention is taken on their strengths and limitations in real-world application. Finally, the current challenges and future perspectives for developing novel highly reliable aptasensors for mycotoxin detection are highlighted, which is expected to provide powerful references for their thorough research and extended applications. Owing to their unique advantages, aptasensors display a fascinating prospect in food field for safety inspection and risk assessment.

Recent advances in synthesis and modification of carbon dots for optical sensing of pesticides.

Serious threat from pesticide residues to the ecosystem and human health has become a global concern. Developing reliable methods for monitoring pesticides is a world-wide research hotspot. Carbon dots (CDs) with excellent photostability, low toxicity, and good biocompatibility have been regarded as the potential substitutes in fabricating various optical sensors for pesticide detection. Based on the relevant high-quality publications, this paper first summarizes the current state-of-the-art of the synthetic and modification approaches of CDs. Then, a comprehensive overview is given on the recent advances of CDs-based optical sensors for pesticides over the past five years, with a particular focus on photoluminescent, electrochemiluminescent and colorimetric sensors regarding the sensing mechanisms and design principles by integrating with various recognition elements including antibodies, aptamers, enzymes, molecularly imprinted polymers, and some nanoparticles. Novel functions and extended applications of CDs as signal indicators, catalyst, co-reactants, and electrode surface modifiers, in constructing optical sensors are specially highlighted. Beyond an assessment of the performances of the real-world application of these proposed optical sensors, the existing inadequacies and current challenges, as well as future perspectives for pesticide monitoring are discussed in detail. It is hoped to provide powerful insights for the development of novel CDs-based sensing strategies with their wide application in different fields for pesticide supervision.

Gut microbiota from patients with arteriosclerotic CSVD induces higher IL-17A production in neutrophils via activating RORγt.

The intestinal microbiota shape the host immune system and influence the outcomes of various neurological disorders. Arteriosclerotic cerebral small vessel disease (aCSVD) is highly prevalent among the elderly with its pathological mechanisms yet is incompletely understood. The current study investigated the ecology of gut microbiota in patients with aCSVD, particularly its impact on the host immune system. We reported that the altered composition of gut microbiota was associated with undesirable disease outcomes and exacerbated inflammaging status. When exposed to the fecal bacterial extracts from a patient with aCSVD, human and mouse neutrophils were activated, and capacity of interleukin-17A (IL-17A) production was increased. Mechanistically, RORγt signaling in neutrophils was activated by aCSVD-associated gut bacterial extracts to up-regulate IL-17A production. Our findings revealed a previously unrecognized implication of the gut-immune-brain axis in aCSVD pathophysiology, with therapeutic implications.

2D Hybrid Architectures Constructed from Two Kinds of Polyoxovanadates as Efficient Heterogeneous Catalysts for Cyanosilylation and Knoevenagel Condensation.

The design of heterogeneous catalysts for highly efficient catalysis for cyanosilylation reactions and Knoevenagel condensations is greatly significant, due to the important application of their products in industry. Herein, five hybrid compounds constructed from two types of polyoxovanadates, [MV12O38]12- (M = Ni, Mn) and [V10O28]6-, were successfully synthesized as heterogeneous catalysts for both reactions, which are {(dpdo)[Ln2(H2O)9(dpdo)][Ln(H2O)5]2[Ln(H2O)4]2[V10O28][NiV12O38]·nH2O} (1, Ln = La, n = 23; 2, Ln = Ce, n = 27; 3, Ln = Pr, n = 27; dpdo = 4,4'-bipyridine N,N'-dioxide) and {(dpdo)[Ln2(H2O)9(dpdo)][Ln(H2O)5]2[Ln(H2O)4]2[V10O28][MnV12O38]·27H2O} (4, Ln = La; 5, Ln = Pr). These compounds were characterized by IR spectroscopy, elemental analysis, TG analysis and X-ray diffraction (single crystal and powder) etc. Compounds 1-5 have similar 2D hybrid structures, in which isopolyvanadate [V10O28]6- and heteropolyvanadate [MV12O38]12- are linked together by hydrated Ln3+ cations and Ln-dpdo coordination complexes. Polyoxovanadates [V10O28]6- and [MV12O38]12- both originate from the transformation of the [MV13O38]7- raw material. This kind of extended structure containing isopolyvanadate and heteropolyvanadate has never been reported hitherto. Because of the Lewis acidity of the Ln3+ cation and the Lewis basicity of the polyoxovanadates, all five compounds exhibit excellent catalytic performance in cyanosilylation and Knoevengel condensation reactions. Especially, compound 3, with a Pr3+ cation, displayed the best catalytic results. Furthermore, these catalysts exhibit a truly heterogeneous nature and good recyclability.

Physical Fitness with Regular Lifestyle Is Positively Related to Academic Performance among Chinese Medical and Dental Students.

OBJECTIVE: The purpose of this study was to examine the relationship between physical fitness, lifestyle, and academic performance of Chinese college students and investigate the differences among medical and dental students on their lifestyle. METHODS: This study was conducted with 316 students enrolled from 2012 to 2014 at Tongji University. Scores from the college physical test were used to represent the students' physical fitness condition. Lifestyle was measured by some variables extracted from the students' behavior data provided by the university's information center. Academic performance was measured by the average score of basic courses and the average score of professional courses. Demographic information, including age, gender, nation, and family background, was also obtained. Separate multiple linear regression analysis was performed for modeling academic performance and physical fitness with a p value threshold of 0.05. RESULTS: A total of 212 (45.97% females) medical students and 104 (58.65% females) dental students participated in this study. Physical fitness score (medical: r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. r = 0.34, p value threshold of 0.05. CONCLUSION: Physical fitness, library usage, and the regularity of lifestyle are significant contributors to academic performance among Chinese medical and dental students. Moreover, medical students are shown to have less rest time compared to dental students.

Corrigendum to "A Trial of Student Self-Sponsored Peer-to-Peer Lending Based on Credit Evaluation Using Big Data Analysis".

[This corrects the article DOI: 10.1155/2019/9898251.].

Multiunit Catalysts with Synergistic Reactivity: Three-Dimensional Polyoxometalate-Based Coordination Polymers for Highly Efficient Synthesis of Functionalized p-Benzoquinones.

The rational design of highly efficient catalysts for the synthesis of functionalized p-benzoquinones (p-BQs) is of great significance for the manufacture of bioactive compounds. Herein, two 3D crystalline polyoxometalate-based coordination polymers (POMCPs) are used as heterogeneous catalysts for the synthesis of p-BQs, which are H[CuII(ttb)(H2O)3]2[CuII(ttb)Cl]2[PW12O40]·4H2O (1) (Httb = 1-(tetrazol-5-yl)-4-(triazol-1-yl)benzene) and [ClCu6I(trz)4][ClCu5I(trz)4]2[CuII(H2O)][PW12O40] (2) (trz = 1,2,4-triazole). Both compounds were characterized by elemental analysis, IR, XPS, solid diffuse reflective spectroscopy, TG analysis, and single-crystal X-ray diffraction. In 1, Keggin anions [PW12O40]3- locate in 1D square channels constructed from wave-like Cu-ttb layers to form a 3D POMCP by coordinating to Cu ions, and in 2, [PW12O40]3- anions situate in eight-membered Cu-trz channels via Cu···O interactions to yield a 3D POMCP structure. The catalytic activities of 1 and 2 have been evaluated in the selective oxidation of alkylphenols/alkoxybenzenes/methylnaphthalene, especially in the oxidation reaction of 2,3,6-trimethylphenol (TMP) to 2,3,5-trimethyl-p-benzoquinone (TMBQ, vitamin E key intermediate), with H2O2 as oxidant. By using catalysts 1 and 2 under optimal conditions, the yield of TMBQ can reach 99% and 96% within 10-20 min, respectively. Both catalysts demonstrated high turnover frequencies (300 h-1 for 1 and 600 h-1 for 2) and the truly heterogeneous nature. 1 and 2 catalyzed the synthesis of p-BQs on the basis of effective cooperative catalytic activities by POMs and metal nodes.

A Trial of Student Self-Sponsored Peer-to-Peer Lending Based on Credit Evaluation Using Big Data Analysis.

There is still no effective approach to overcome the problem of credit evaluation for Chinese students. In absence of a reliable credit evaluation system for students, the university students have to only apply through online peer-to-peer (P2P) loan platforms because Chinese financial institutions typically reject students' loan applications. Lack of students' financial records hinders financial institutes and banks to routinely evaluate the students' credit status and assign loans to them. Hence, this paper attempted to benefit from university students' diversified daily behavior data, and logistic regression (LR) and gradient boosting decision tree (GBDT) algorithms were also used to develop robust credit evaluation models for university students, in which the validation of the proposed models was assessed by a real-time P2P lending platform. In this study, the students' overdue behavior in returning books to university library was used as an index. With training 17838 samples, the proposed models performed well, while GBDT-based model outperformed in identification of "bad borrowers." Based on the proposed models, a self-sponsored peer-to-peer loan platform was established and developed in a Chinese university for ten months, and the achieved findings demonstrated that adopting such credit evaluation models can effectively reduce the default ratio.

Hybrid dimers based on metal-substituted Keggin polyoxometalates (metal = Ti, Ln) for cyanosilylation catalysis.

Six novel organic-inorganic hybrid polyoxometalate derivatives, K[(H2O)4(3-Hpic)2Ce][(H2O)5(3-Hpic)2Ce][PW10Ti2O40]·11H2O 1, K[(H2O)4(3-Hpic)2Nd][(H2O)5(3-Hpic)2Nd][PW10Ti2O40]·12H2O 2, K[(H2O)4(3-Hpic)2Sm][(H2O)5(3-Hpic)2Sm][PW10Ti2O40]·8H2O 3, H[(H2O)7(4-Hpic)La][(4-Hpic)2LaPW11O39]·14.5H2O 4, H[(H2O)7(4-Hpic)Ce][(4-Hpic)2CePW11O39]·7.5H2O 5, and K(4-Hpic)0.5[(H2O)6(4-Hpic)Nd][(4-Hpic)2NdPW11O39]·10H2O 6, (3-Hpic = 3-picolinic acid; 4-Hpic = 4-picolinic acid) have been synthesized and characterized by elemental analysis, IR, solid state UV-vis spectroscopy, thermal gravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Isostructural compounds 1-3 are hybrid dimers that consist of two Ti-substituted Keggin-type polyoxoanions [PW10Ti2O40]7- and four Ln-3-Hpic coordination groups. The strong hydrogen bonds in 1-3 can make these dimers yield a 1D supramolecular chain. Compounds 4-6 are also dimers constructed from two lanthanide-substituted Keggin-type polyoxoanions [PW11LnO39]4- and four 4-Hpic ligands, which are further linked by two Ln-4-Hpic groups to form a bi-supporting structure. Then these subunits are joined together by strong hydrogen-bonding interactions between polyoxoanions and coordinated water molecules to produce a 2D supramolecular framework. All these compounds as heterogeneous Lewis acid-base catalysts show high activity and high selectivity for the cyanosilylation of different carbonyl compounds under solvent-free conditions, and can be recycled without any obvious inactivation.

Evans-Showell-Type Polyoxometalates Constructing High-Dimensional Inorganic-Organic Hybrid Compounds with Copper-Organic Coordination Complexes: Synthesis and Oxidation Catalysis.

Four new hybrid architectures containing a [Co2Mo10H4O38]6- polyoxoanion, (en)[Cu3(ptz)4(H2O)4][Co2Mo10H4O38]·24H2O (1), (Hbim)2[{Cu(bim)2(H2O)2}2{Co2Mo10H4O38}]·5H2O (2), H2[Cu(dpdo)3(H2O)4][{Cu2(dpdo)3(H2O)4(CH3CN)}2{Co2Mo10H4O38}2]·9H2O (3), and (H2bpp)4[{Cu(H2O)2}{NaCo2Mo10H4O38}2]·10H2O (4), where ptz = 5-(4-pyridyl)-1H-tetrazole, en = ethylenediamine, bim = benzimidazole, dpdo = 4,4'-bipyridine-N,N'-dioxide, and bpp = 1,3-bis(4-pyridyl)propane, have been prepared and characterized through elemental analysis, thermogravimetric analysis, IR spectroscopy, and powder and single-crystal X-ray diffraction. Compound 1 shows a 3D host-guest framework composed of 3D Cu-ptz as the host and Evans-Showell-type polyoxoanion [Co2Mo10H4O38]6- as the guest. Compound 2 is constructed from [Co2Mo10H4O38]6- polyoxoanions and Cu-bim coordination complexes to form a 2D covalent layer. Compound 3 also exhibits a 2D hybrid network based on [Co2Mo10H4O38]6- polyoxoanions linked by Cu-dpdo coordination groups. Compound 4 is a 1D double-chain structure composed of [Co2Mo10H4O38]6- polyoxoanions joined together by Na+ and Cu2+ cations. As far as we know, compound 1 is the first host-guest compound with an Evans-Showell-type polyoxometalate as the guest, and compounds 2 and 3 are the first 2D inorganic-organic hybrid architectures constructed from Evans-Showell-type polyoxometalates. Compounds 1-4 are redox catalysts that heterogeneously prompt sulfide and alcohol oxidation with excellent efficiency.