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  • 1
    In: Microorganisms, MDPI AG, Vol. 10, No. 12 ( 2022-11-26), p. 2342-
    Abstract: Cyclic dimeric guanosine monophosphate (c-di-GMP) is synthesized by diguanylate cyclase (DGC) with the GGDEF domain. As a ubiquitous bacterial second messenger, it regulates diverse life-activity phenotypes in some bacteria. Although 38 genes encoding GGDEF-domain-containing proteins have been identified in the genome of the Pseudomonas glycinae strain MS82, whether c-di-GMP functions as a facilitator or repressor of life-activity phenotypes is poorly understood. In this study, one of the 38 genes containing a GGDEF domain in MS82, PafS was investigated to explore its regulatory function in bacterial life activities. The PafS-deletion mutant ΔPafS and reversion mutant PafS-comp were constructed by the method of biparental conjugation and homologous recombination. The life activities of the mutants, such as antifungal activity, biofilm formation ability, polysaccharide content, and motor behavior, were explored. The results showed that all life-activity phenotypes were significantly reduced after knocking out PafS, whereas all were significantly restored to a similar level to that of MS82 after the complementation of PafS. These results suggested that PafS plays an important role in the regulation of a range of cellular activities by c-di-GMP in P. glycinae MS82.
    Type of Medium: Online Resource
    ISSN: 2076-2607
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2720891-6
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  • 2
    In: Nanomaterials, MDPI AG, Vol. 10, No. 9 ( 2020-09-09), p. 1795-
    Abstract: In work, (002) oriented flower-like Bi2O2CO3(BOC) composites are synthesized by a facile chemical route and carbon quantum dots (CQDs) are modified on their surfaces through a hydrothermal method. The synthesized samples (CQD/BOC) are characterized by X-ray diffraction (XRD), SEM, X-ray photoelectron spectroscopy (XPS), UV-Vis diffuser reflectances (DRS), BET and TEM/HRTEM. The morphologies of CQD/BOC composites are the flower-like shapes, the irregular flaky structures and the fine spherical particles of CQDs attached. Photocatalytic performances were investigated in terms of removing gaseous toluene at a concentration of 94.3ppm in air, with the assistance of CQD/BOC under artificial irradiation. Our results show that CQDs modified (002) oriented Bi2O2CO3 exhibits good photocatalytic activity for toluene decomposition, which can be attributed to the enhanced efficient charge separation. A certain ratio composite photocatalyst (BOC-CQD-15) shows a toluene removal rate of 96.62% in three hours, as well as great stability. CO2 was verified to be the primary product. The oriented flower-like Bi2O2CO3 with carbon quantum dots on the surface shows great potential in the field of solar driven air purification.
    Type of Medium: Online Resource
    ISSN: 2079-4991
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2662255-5
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  • 3
    In: Horticulturae, MDPI AG, Vol. 9, No. 4 ( 2023-03-29), p. 446-
    Abstract: Cyclic diguanylate (c-di-GMP) affects bacterial physiological and biochemical functions like biofilm, motility, virulence, and bacterial secretion systems. GGDEF/EAL-domain proteins, participating in c-di-GMP synthesis and degradation, are widely present in Pseudomonas, with various structures and functions. Pseudomonas glycinae MS82 is a rhizosphere bacterium that protects mushroom against the pathogenic fungi. Although 14 genes encoding GGDEF/EAL-domain proteins have been identified in the genome of MS82, c-di-GMP regulation is poorly understood as a facilitator or repressor of physiological phenotypes. Here, PafQ and PafR, encoding the proteins with the tandem GGDEF/EAL domain, were functionally analyzed and found to regulate antifungal activity. Individual deletion mutants of PafQ and PafR were constructed in P. glycinae MS82 through biparental conjugation and homologous recombination. Subsequently, antifungal activity, biofilm formation, motility, and expression of the genes related to antifungal substance synthesis were examined and contrasted with those of wild-type P. glycinae MS82. Most phenotypes of physiological activities were significantly reduced after knocking out PafQ or PafR. In other members of the genus Pseudomonas, homologous genes of PafQ and PafR possess different functions in c-di-GMP regulation. In P. glycinae, the positive regulation of PafQ and PafR on fungistatic substance synthesis, biofilm formation, and motility is crucial in the biocontrol of mushroom diseases.
    Type of Medium: Online Resource
    ISSN: 2311-7524
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2813983-5
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  • 4
    In: Crystals, MDPI AG, Vol. 11, No. 6 ( 2021-06-18), p. 703-
    Abstract: Particles that modify delivery characteristics are a focus of drug-loading research. Hydroxyapatite particles (HAPs) have excellent biocompatibility, shape controllability, and high adsorption, making them a potential candidate for drug-delivery carriers. However, there are still some defects in the current methods used to prepare HAPs. In order to avoid agglomeration and improve the drug-loading properties of HAPs, the present study provides a novel triethylamine (TEA)-capped coprecipitation template method to prepare HAPs at room temperature. In addition, pure water and anhydrous ethanol were used as solvents to investigate the capping effect of the small-molecule capping agent TEA during the synthesis of HAPs. The results showed that the HAPs prepared in the TEA ethanol system had a smaller particle size (150–250 nm), better dispersion and higher crystallinity. The results were significantly different from those of the conventional preparation methods without TEA. However, the hydroxyapatite crystal would agglomerate to a certain extent after being stored for a period of time, forming micro/nano-sized agglomerates of nanocrystals. FITR analysis and SEM observation showed that the capping effect of TEA promoted the formation of a smaller template and dispersed HAPs were quickly formed by dissolution and reprecipitation processes. The drug-loading experiments showed that the HAPs prepared in the TEA ethanol system had high drug-loading capacity (239.8 ± 13.4 mg·g−1) as well as an improved drug-release profile demonstrated in the drug-release experiment. The larger specific surface area associated with the smaller particle size was beneficial to the adsorption of drugs. After drying at 60 °C, TEA was evaporated from the HAPs which agglomerated into larger micron particles with more drug encapsulated. Thus, the effect of a sustained release was achieved. In the present research, a novel approach was developed by using triethylamine as the capping agent to prepare micro/nano-sized agglomerates of HAP nanocrystals with improved drug loading, which is predicted to have potential application in drug delivery.
    Type of Medium: Online Resource
    ISSN: 2073-4352
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661516-2
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  • 5
    In: Journal of Clinical Medicine, MDPI AG, Vol. 11, No. 8 ( 2022-04-18), p. 2267-
    Abstract: The aim of this study was combining multi-level resting-state functional magnetic resonance imaging (rs-fMRI) features with machine learning method to distinguish breast cancer patients with chemotherapy-related subjective cognitive complaints (SCC) from non-chemotherapy (BC) and healthy controls (HC). Forty subjects in SCC group, forty-nine in BC group and thirty-four in HC group were recruited and underwent rs-fMRI scanning. Based on the anatomical automatic labeling brain atlas, the functional metrics of all subjects included functional connectivity, amplitude of low frequency fluctuation and fractional amplitude of low frequency fluctuation, regional homogeneity, voxel-mirrored homotopic connectivity and degree centrality were calculated and extracted as features set. Then, the rs-fMRI features were selected by two-sample t-test, removing variables with a high pairwise correlation and least absolute shrinkage and selection operator regression. Finally, the support vector machine models were built for classification (SCC vs. BC, SCC vs. HC). Thirty-eight features (SCC vs. BC) and seventeen features (SCC vs. HC) were selected separately, and the accuracy of the models were 82.0% and 91.9%, respectively. These findings demonstrated a valid machine learning approach that effectively distinguished breast cancer patients with chemotherapy-related SCC from non-chemotherapy and healthy controls, providing potential neuroimaging evidence for early diagnosis and clinical intervention of chemotherapy-related SCC.
    Type of Medium: Online Resource
    ISSN: 2077-0383
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662592-1
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  • 6
    In: Diagnostics, MDPI AG, Vol. 12, No. 4 ( 2022-04-02), p. 888-
    Abstract: Background: The aim of this study was to evaluate the efficacy of a deep learning system in pterygium grading and recurrence prediction. Methods: This was a single center, retrospective study. Slit-lamp photographs, from patients with or without pterygium, were collected to develop an algorithm. Demographic data, including age, gender, laterality, grading, and pterygium area, recurrence, and surgical methods were recorded. Complex ocular surface diseases and pseudopterygium were excluded. Performance of the algorithm was evaluated by sensitivity, specificity, F1 score, accuracy, and area under the receiver operating characteristic curve. Confusion matrices and heatmaps were created to help explain the results. Results: A total of 237 eyes were enrolled, of which 176 eyes had pterygium and 61 were non-pterygium eyes. The training set and testing set were comprised of 189 and 48 photographs, respectively. In pterygium grading, sensitivity, specificity, F1 score, and accuracy were 80% to 91.67%, 91.67% to 100%, 81.82% to 94.34%, and 86.67% to 91.67%, respectively. In the prediction model, our results showed sensitivity, specificity, positive predictive value, and negative predictive values were 66.67%, 81.82%, 33.33%, and 94.74%, respectively. Conclusions: Deep learning systems can be useful in pterygium grading based on slit lamp photographs. When clinical parameters involved in the prediction of pterygium recurrence were included, the algorithm showed higher specificity and negative predictive value in prediction.
    Type of Medium: Online Resource
    ISSN: 2075-4418
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662336-5
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  • 7
    In: Catalysts, MDPI AG, Vol. 10, No. 4 ( 2020-04-02), p. 389-
    Abstract: Layer-structured Bi2O2CO3 is a novel photocatalyst for eliminating environmental pollutants. In this work, Bi2O2CO3 nanosheets were synthesized by hydrothermal methods, followed by annealing in nitrogen. (002) oriented Bi2O2CO3 nanosheets were obtained and characterized by XRD, SEM, XPS, BET and UV-Vis diffuse reflectance spectra. Photocatalytic properties were investigated by toluene removal in air, with the assistant of Bi2O2CO3 nanosheets under artificial irradiation. Our results show that Bi2O2CO3 annealed in nitrogen exhibited high full-light-driven photocatalytic activity for toluene photocatalytic decomposition, which may be ascribed to facet orientation evolution during the annealing process and enhanced efficient charge separation. The sample annealed at 150 °C for 8 h (BOC-150-8 h) showed high stability and the highest toluene removal rate, which was up to 99%. The final degradation products were detected by gas chromatography–mass spectrometer (GC-MS) and CO2 was verified to be the primary product. Photocatalytic mineralization of toluene in air over Bi2O2CO3 was proposed. This work may provide a foundation for application of annealed Bi2O2CO3 in indoor air purification.
    Type of Medium: Online Resource
    ISSN: 2073-4344
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2662126-5
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  • 8
    In: Catalysts, MDPI AG, Vol. 13, No. 6 ( 2023-05-31), p. 956-
    Abstract: Currently, the catalytic reduction of nitrobenzene requires more efficient and low-cost catalysts. In this work, a new copper-based metal-organic framework (MOF) was designed by the calcination of Cu–MOF at 700 °C (denoted as Cu@C). The catalyst showed superior catalytic performance toward the reduction of nitrobenzene, using sodium borohydride (NaBH4) as the reducing agent, and the catalyst exhibited high nitrobenzene conversion (100%) and a quick reaction time (8 min). This was one of the highest efficiencies among non-noble metal catalysts reported so far, as general non-noble metal catalysts typically require more than 15 min. This catalyst had excellent acid resistance after etching using sulfuric acid (H2SO4) for 24 h with a nitrobenzene conversion rate that was still more than 90%. In addition, it could be used more than five times and the catalytic properties remained essentially unchanged, without any reactivation treatment. Therefore, this study could offer a new efficient non-noble metal catalyst for the reduction of nitro compounds.
    Type of Medium: Online Resource
    ISSN: 2073-4344
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2662126-5
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  • 9
    In: Forests, MDPI AG, Vol. 14, No. 1 ( 2023-01-07), p. 114-
    Abstract: As a consequence of changing global rainfall patterns, frequent extreme droughts will significantly affect plant growth and ecosystem functions. Fine roots and arbuscular mycorrhizal fungi (AMF) both facilitate Chinese fir nutrient uptake. However, how the growth of fine roots and AMF is regulated for the Chinese fir under drought conditions is unclear. This study used a precipitation reduction treatment (−50% throughfall) to study the seasonal effects of drought on a subtropical Chinese fir plantation. The effects measured included the fine root production, root diameter, specific root length, specific surface area, root tissue density, mycorrhizal hyphal density, spore number, mycorrhizal infection rate and total glomalin. Drought had no significant effect on Chinese fir fine root production but decreased the diameter and tissue density of primary and secondary roots while increasing the specific surface area of secondary roots. Additionally, drought significantly decreased the arbuscular mycorrhizal infection rate and significantly increased hyphal density. The results showed that drought caused the decrease in root diameter, which decreased the surface area available for AMF infection and led to the increase in mycorrhizal hyphal density. Redundancy analyses showed that soil-dissolved organic carbon and nitrogen were the key factors affecting AMF. Our results show that drought could enhance the cooperative strategy of nutrient and moisture absorption by roots and mycorrhizae of the Chinese fir, improving the resistance of Chinese fir growth to drought.
    Type of Medium: Online Resource
    ISSN: 1999-4907
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2527081-3
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  • 10
    In: Materials, MDPI AG, Vol. 10, No. 4 ( 2017-04-24), p. 443-
    Type of Medium: Online Resource
    ISSN: 1996-1944
    Language: English
    Publisher: MDPI AG
    Publication Date: 2017
    detail.hit.zdb_id: 2487261-1
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