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  • MDPI AG  (371)
  • 1
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    Ilmenite Alteration and Its Adsorption and Catalytic Reduction in U Enrichment in Sandstone-Hosted U Deposits from the Northern Ordos Basin, North China
    MDPI AG ; 2022
    In:  Minerals Vol. 12, No. 2 ( 2022-01-28), p. 167-
    Details
    In: Minerals, MDPI AG, Vol. 12, No. 2 ( 2022-01-28), p. 167-
    Abstract: Detrital ilmenite and its altered minerals are common in sandstone-hosted U deposits in the northern Ordos Basin, north China. Petrographic observation, SEM-EDS, EMPA, and LA-MC-ICP-MS were utilized to characterize the spatial relationship between altered ilmenite and the U minerals, and to investigate the U enrichment mechanism and alteration processes of ilmenite. Ilmenite was completely or partially altered to leucoxene and anatase along its rim and crack in ore-bearing sandstone. Framboidal and cement pyrite of BSR and TSR origin were identified around altered ilmenite. Two U phases closely related to altered ilmenite contain Ti-coffinite (I) and coffinite (II). These data indicate that ilmenite alteration and the associated processes of U enrichment can be divided into two stages. Stage one involves U pre-enrichment and adsorption, with stage two involving U enrichment via TiO2 (leucoxene and anatase) catalytic reduction. Ilmenite was altered into porous leucoxene that can adsorb U as uraniferous leucoxene and Ti-coffinite (I) and framboidal pyrite directly by reactions with H2S, produced by sulfate-reducing bacteria during synsedimentary and early diagenesis stages. Altered ilmenite can enrich U in the form of coffinite (II) through a catalytic reduction reaction which is triggered by β and γ radiation produced by previously adsorbed U during the uplift of ore-bearing bed in the Late Cretaceous period. In addition, cement pyrite can also reduce U6+ into U4+ which deposits on its surface in the form of coffinite (II). These results demonstrate a new mechanism, mediated by adsorption and catalytic reduction, to enrich U in sandstone-hosted U deposits.
    Type of Medium: Online Resource
    ISSN: 2075-163X
    URL: Article
    DOI: 10.3390/min12020167
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2655947-X
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  • 2
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    Temperature Rise Characteristics of Silicon Avalanche Photodiodes in Different External Capacitance Circuits Irradiated by Infrared Millisecond Pulse Laser
    MDPI AG ; 2021
    In:  Crystals Vol. 11, No. 8 ( 2021-07-26), p. 866-
    Details
    In: Crystals, MDPI AG, Vol. 11, No. 8 ( 2021-07-26), p. 866-
    Abstract: We experimentally studied the interaction between a millisecond pulse laser and silicon avalanche photodiode (Si-APD) in an external capacitance circuit. The temperature rise law of Si-APD irradiated by a millisecond pulse laser under different external capacitance conditions was obtained. The results show that the surface temperature rise in a Si-APD is strongly dependent on the external capacitance. That is, the smaller the external capacitance, the smaller the surface temperature rise. The effect of the external capacitance on the surface temperature rise in a Si-APD was investigated for the first time in the field of laser damage. The research results have a certain practical significance for the damage and protection of mid-infrared detectors.
    Type of Medium: Online Resource
    ISSN: 2073-4352
    URL: Article
    DOI: 10.3390/cryst11080866
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661516-2
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  • 3
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    Comprehensive Analysis of 34 Edible Flowers by the Determination of Nutritional Composition and Antioxidant Capacity Planted in Yunnan Province China
    MDPI AG ; 2023
    In:  Molecules Vol. 28, No. 13 ( 2023-07-06), p. 5260-
    Details
    In: Molecules, MDPI AG, Vol. 28, No. 13 ( 2023-07-06), p. 5260-
    Abstract: The main purpose of this study was to reveal the nutritional value and antioxidant activity of 34 edible flowers that grew in Yunnan Province, China, through a comprehensive assessment of their nutritional composition and antioxidant indices. The results showed that sample A3 of Asteraceae flowers had the highest total flavonoid content, with a value of 8.53%, and the maximum contents of vitamin C and reducing sugars were from Rosaceae sample R1 and Gentianaceae sample G3, with values of 143.80 mg/100 g and 7.82%, respectively. Samples R2 and R3 of Rosaceae were the top two flowers in terms of comprehensive nutritional quality. In addition, the antioxidant capacity of Rosaceae samples was evidently better than that of three others, in which Sample R1 had the maximum values in hydroxyl radical (·OH) scavenging and superoxide anion radical (·O2−) scavenging rates, and samples R2 and R3 showed a high total antioxidant capacity and 2,2-diphenyl-1-pyridylhydrazine (DPPH) scavenging rate, respectively. Taken together, there were significant differences in the nutrient contents and antioxidant properties of these 34 flowers, and the comprehensive quality of Rosaceae samples was generally better than the other three families. This study provides references for 34 edible flowers to be used as dietary supplements and important sources of natural antioxidants.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules28135260
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2008644-1
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  • 4
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    Directed Accumulation of Nitrogen Metabolites through Processing Endows Wuyi Rock Tea with Singular Qualities
    MDPI AG ; 2022
    In:  Molecules Vol. 27, No. 10 ( 2022-05-19), p. 3264-
    Details
    In: Molecules, MDPI AG, Vol. 27, No. 10 ( 2022-05-19), p. 3264-
    Abstract: The execution of specific processing protocols endows Wuyi rock tea with distinctive qualities produced through signature metabolic processes. In this work, tea leaves were collected before and after each of three processing stages for both targeted and untargeted metabolomic analysis. Metabolic profiles of processing stages through each processing stage of rotation, pan-firing and roasting were studied. Overall, 614 metabolites were significantly altered, predominantly through nitrogen- enriching (N) pathways. Roasting led to the enrichment of 342 N metabolites, including 34 lipids, 17 organic acids, 32 alkaloids and 25 amino acids, as well as secondary derivatives beneficial for tea quality. This distinctive shift towards enrichment of N metabolites strongly supports concluding that this directed accumulation of N metabolites is how each of the three processing stages endows Wuyi rock tea with singular quality.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules27103264
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2008644-1
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  • 5
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    The Simultaneous Determination of Chlorpyrifos–Ethyl and –Methyl with a New Format of Fluorescence-Based Immunochromatographic Assay
    MDPI AG ; 2022
    In:  Biosensors Vol. 12, No. 11 ( 2022-11-11), p. 1006-
    Details
    In: Biosensors, MDPI AG, Vol. 12, No. 11 ( 2022-11-11), p. 1006-
    Abstract: The improper and excessive use in agriculture of chlorpyrifos–methyl (CPSM) and chlorpyrifos–ethyl (CPSE) may affect the health of human beings. Herein, a fluorescence-based immunochromatographic assay (FICA) was developed for the simultaneous determination of CPSM and CPSE. A monoclonal antibody (mAb) with equal recognition of CPSM and CPSE was generated by the careful designing of haptens and screening of hybridoma cells. Instead of labeling fluorescence with mAb, the probe was labeled with goat-anti-mouse IgG (GAM-IgG) and pre-incubated with mAb in the sample. The complex could compete with CPS by coating antigen in the test line. The new format of FICA used goat-anti-rabbit IgG (GAR-IgG) conjugated with rabbit IgG labeled with fluorescence microspheres as an independent quality control line (C line). The novel strategy significantly reduced nonspecific reactions and increased assay sensitivity. Under the optimal conditions, the proposed FICA showed a linear range of 0.015–64 mg/L and limit of detection (LOD) of 0.015 mg/L for both CPSE and CPSM. The average recoveries of CPS from spiked food samples by FICA were 82.0–110.0%. The accuracy was similar to the gas chromatography–tandem mass spectrometry (GC-MS/MS) results. The developed FICA was an ideal on-site tool for rapid screening of CPS residues in foods.
    Type of Medium: Online Resource
    ISSN: 2079-6374
    URL: Article
    DOI: 10.3390/bios12111006
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662125-3
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  • 6
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    Exploring the In Vivo Existence Forms (23 Original Constituents and 147 Metabolites) of Astragali Radix Total Flavonoids and Their Distributions in Rats Using HPLC-DAD-ESI-IT-TOF-MSn
    MDPI AG ; 2020
    In:  Molecules Vol. 25, No. 23 ( 2020-11-26), p. 5560-
    Details
    In: Molecules, MDPI AG, Vol. 25, No. 23 ( 2020-11-26), p. 5560-
    Abstract: Astragali Radix total flavonoids (ARTF) is one of the main bioactive components of Astragali Radix (AR), and has many pharmacological effects. However, its metabolism and effective forms remains unclear. The HPLC-DAD-ESI-IT-TOF-MSn technique was used to screen and tentatively identify the in vivo original constituents and metabolites of ARTF and to clarify their distribution in rats after oral administration. In addition, modern chromatographic methods were used to isolate the main metabolites from rat urine and NMR spectroscopy was used to elucidate their structures. As a result, 170 compounds (23 original constituents and 147 metabolites) were tentatively identified as forms existing in vivo, 13 of which have the same pharmacological effect with ARTF. Among 170 compounds, three were newly detected original constituents in vivo and 89 were new metabolites of ARTF, from which 12 metabolites were regarded as new compounds. Nineteen original constituents and 65 metabolites were detected in 10 organs. Four metabolites were isolated and identified from rat urine, including a new compound (calycoisn-3’-O-glucuronide methyl ester), a firstly-isolated metabolite (astraisoflavan-7-O-glucoside-2’-O-glucuronide), and two known metabolites (daidzein-7-O-sulfate and calycosin-3’-O-glucuronide). The original constituents and metabolites existing in vivo may be material basis for ARTF efficacy, and these findings are helpful for further clarifying the effective forms of ARTF.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules25235560
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2008644-1
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  • 7
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    Characterization of the In Vitro Cultured Ovarian Cells in the Asian Yellow Pond Turtle (Mauremys mutica)
    MDPI AG ; 2022
    In:  Biology Vol. 11, No. 10 ( 2022-09-26), p. 1404-
    Details
    In: Biology, MDPI AG, Vol. 11, No. 10 ( 2022-09-26), p. 1404-
    Abstract: Gonadal cell lines possess the abilities of self-renewal and differentiation, being used as an efficient tool to analyzing the genes’ functions involved in sex differentiation and gametogenesis. Although some significant achievements have been obtained in the gonadal cells’ culture or manipulation across multiple phyla including teleost and mammals, there is limited study on gonadal cell manipulation in turtles. In this study, we established a new ovarian cell line from the young Asian yellow pond turtle (Mauremys mutica), which exhibited a normal diploid karyotype with high alkaline phosphatase activity. The cell line, designated as YTO2, was then characterized through the analysis of gene expression profiles. The transcriptome analysis and the reverse transcription polymerase chain reaction (RT-PCR) showed that the cells expressed germline genes such as tdrd7, nanos1, klf5, igtb1, hsd17b4 and rad51. Moreover, the immunostaining showed that the germ cell markers, Tdrd7 and Rad51 proteins, were detected predominant in cytoplasm of perinuclear region, while proliferation marker, PCNA, was dominantly observed in the nuclei of cultured cells. Intriguingly, the cells could respond to the retinoic acid induction with significantly increasing the expression level of some meiosis genes, including vasa, dazl, figla, and dmc1. Furthermore, YTO2 cells could be efficiently transfected with the pHBAd-BHG-EGFP adenovirus and properly expressed the exogenous genes. To sum up, an ovarian cell line of the Asian yellow pond turtle had been established and could be stably propagated under in vitro culture condition, as well as being capable of efficiently expressing the exogenous gene tdrd7. This cell line would provide a valuable tool to elaborate the molecular mechanisms behind germ cells development, differentiation and oogenesis in the turtle, even in reptiles.
    Type of Medium: Online Resource
    ISSN: 2079-7737
    URL: Article
    DOI: 10.3390/biology11101404
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2661517-4
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  • 8
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    Genome-Wide mRNA and Long Non-Coding RNA Analysis of Porcine Trophoblast Cells Infected with Porcine Reproductive and Respiratory Syndrome Virus Associated with Reproductive Failure
    MDPI AG ; 2023
    In:  International Journal of Molecular Sciences Vol. 24, No. 2 ( 2023-01-04), p. 919-
    Details
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 24, No. 2 ( 2023-01-04), p. 919-
    Abstract: Porcine reproductive and respiratory syndrome (PRRS) is a vertically transmitted reproductive disorder that is typically characterized by miscarriage, premature birth, and stillbirth in pregnant sows after infection. Such characteristics indicate that PRRSV can infect and penetrate the porcine placental barrier to infect fetus piglets. The porcine trophoblast is an important component of the placental barrier, and secretes various hormones, including estrogen and progesterone, to maintain normal pregnancy and embryonic development during pregnancy. It is conceivable that the pathogenic effects of PRRSV infection on porcine trophoblast cells may lead to reproductive failure; however, the underlying detailed mechanism of the interaction between porcine trophoblast (PTR2) cells and PRRSV is unknown. Therefore, we conducted genome-wide mRNA and long non-coding RNA (lncRNA) analysis profiling in PRRSV-infected PTR2. The results showed that 672 mRNAs and 476 lncRNAs were significantly different from the control group after viral infection. Target genes of the co-expression and co-location of differential mRNAs and lncRNAs were enriched by GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, revealing that most of the pathways were involved in cell nutrient metabolism, cell proliferation, and differentiation. Specifically, the estrogen signaling pathway, the PI3K (PhosphoInositide-3 Kinase)-Akt (serine/threonine kinase) signaling pathway, and the insulin secretion related to embryonic development were selected for analysis. Further research found that PRRSV inhibits the expression of G-protein-coupled estrogen receptor 1 (GPER1), thereby reducing estrogen-induced phosphorylation of AKT and the mammalian target of rapamycin (mTOR). The reduction in the phosphorylation of AKT and mTOR blocks the activation of the GPER1- PI3K-AKT-mTOR signaling pathway, consequently restraining insulin secretion, impacting PTR2 cell proliferation, differentiation, and nutrient metabolism. We also found that PRRSV triggered trophoblast cell apoptosis, interrupting the integrity of the placental villus barrier. Furthermore, the interaction network diagram of lncRNA, regulating GPER1 and apoptosis-related genes, was constructed, providing a reference for enriching the functions of these lncRNA in the future. In summary, this article elucidated the differential expression of mRNA and lncRNA in trophoblast cells infected with PRRSV. This infection could inhibit the PI3K-AKT-mTOR pathway and trigger apoptosis, providing insight into the mechanism of the vertical transmission of PRRSV and the manifestation of reproductive failure.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    URL: Article
    DOI: 10.3390/ijms24020919
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 9
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    Salivary Cortisol Determination on Smartphone-Based Differential Pulse Voltammetry System
    MDPI AG ; 2020
    In:  Sensors Vol. 20, No. 5 ( 2020-03-05), p. 1422-
    Details
    In: Sensors, MDPI AG, Vol. 20, No. 5 ( 2020-03-05), p. 1422-
    Abstract: Cortisol is commonly used as a significant biomarker of psychological or physical stress. With the accelerated pace of life, non-invasive cortisol detection at the point of care (POC) is in high demand for personal health monitoring. In this paper, an ultrasensitive immunosensor using gold nanoparticles/molybdenum disulfide/gold nanoparticles (AuNPs/MoS2/AuNPs) as transducer was explored for non-invasive salivary cortisol monitoring at POC with the miniaturized differential pulse voltammetry (DPV) system based on a smartphone. Covalent binding of cortisol antibody (CORT-Ab) onto the AuNPs/MoS2/AuNPs transducer was achieved through the self-assembled monolayer of specially designed polyethylene glycol (PEG, SH-PEG-COOH). Non-specific binding was avoided by passivating the surface with ethanolamine. The miniaturized portable DPV system was utilized for human salivary cortisol detection. A series current response of different cortisol concentrations decreased and exhibited a linear range of 0.5–200 nM, the detection limit of 0.11 nM, and high sensitivity of 30 μA M−1 with a regression coefficient of 0.9947. Cortisol was also distinguished successfully from the other substances in saliva. The recovery ratio of spiked human salivary cortisol and the variation of salivary cortisol level during one day indicated the practicability of the immunosensor based on the portable system. The results demonstrated the excellent performance of the smartphone-based immunosensor system and its great potential application for non-invasive human salivary cortisol detection at POC.
    Type of Medium: Online Resource
    ISSN: 1424-8220
    URL: Article
    DOI: 10.3390/s20051422
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2052857-7
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  • 10
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    An Improved MLVF Method and Its Comparison with Traditional MLVF, spa Typing, MLST/SCCmec and PFGE for the Typing of Methicillin-Resistant Staphylococcus aureus
    MDPI AG ; 2014
    In:  International Journal of Molecular Sciences Vol. 15, No. 1 ( 2014-01-08), p. 725-742
    Details
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 15, No. 1 ( 2014-01-08), p. 725-742
    Type of Medium: Online Resource
    ISSN: 1422-0067
    URL: Article
    DOI: 10.3390/ijms15010725
    Language: English
    Publisher: MDPI AG
    Publication Date: 2014
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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