Multilocus phylogenetic analysis of <i>Talaromyces</i> species isolated from cucurbit plants in China and description of two new species, <i>T. cucurbitiradicus</i> and <i>T. endophyticus</i>

<p>During a survey of endophytic fungi from cucurbit plants in China, 21 <i>Talaromyces</i> strains were isolated from ten symptomless plants. Phylogenetic analysis of the partial RNA polymerase II largest subunit gene (<i>RPB2</i>) showed that the strains belong to <i>Talaromyces</i> sections <i>Talaromyces</i> and <i>Islandici</i>. Based on morphological characters and multilocus phylogenetic analysis of the nuc rDNA internal transcribed spacer region (ITS1-5.8S-ITS2 = ITS), calmodulin (<i>CaM</i>), and β-tubulin (<i>TUB</i>) genes, the strains were identified as four known species, <i>T. cnidii, T. pinophilus, T. radicus</i>, and <i>T. wortmannii</i>, and two new species. Two new species, <i>T. cucurbitiradicus</i> from pumpkin roots and <i>T. endophyticus</i> from cucumber stems, are described in this study. <i>Talaromyces cucurbitiradicus</i> is morphologically similar to <i>T. funiculosus</i> but differs in the number of phialides per metula and by the production of chlamydospores. <i>Talaromyces endophyticus</i> is morphologically similar to <i>T. cerinus</i> and <i>T. chlamydosporus</i> but differs by producing yellowish colonies and by lacking chlamydospores. Further analyses of polymorphisms in ITS and <i>TUB</i> sequences supported the distinctions among <i>T. cucurbitiradicus, T. endophyticus</i>, and similar species.</p

Role of Organic Solvents in Immobilizing Fungus Laccase on Single-Walled Carbon Nanotubes for Improved Current Response in Direct Bioelectrocatalysis

Improving bioelectrocatalytic current response of redox enzymes on electrodes has been a focus in the development of enzymatic biosensors and biofuel cells. Herein a mediatorless electroreduction of oxygen is effectively improved in terms of a remarkable enhancement by ca. 600% in maximum reductive current by simply adding 20% ethanol into laccase solution during its immobilization onto single-walled carbon nanotubes (SWCNTs). Conformation analysis by circular dichroism and attenuated total reflectance infrared spectroscopy demonstrate promoted laccase-SWCNTs contact by ethanol, thus leading to favorable enzyme orientation on SWCNTs. Extended investigation on acetone-, acetonitrile-, <i>N</i>,<i>N</i>-dimethylformamide (DMF)-, or dimethyl sulfoxide (DMSO)-treated laccase-SWCNTs electrodes shows a 400% and 350% current enhancement at maxima upon acetone and acetonitrile treatment, respectively, and a complete diminish of reductive current by DMF and DMSO. These results together reveal the important role of organic solvents in regulating laccase immobilization for direct bioelectrocatalysis by balancing surface wetting and protein denaturing

Chemical Etching of Bovine Serum Albumin-Protected Au25 Nanoclusters for Label-Free and Separation-Free Ratiometric Fluorescent Detection of Tris(2-carboxyethyl)phosphine

This study describes a novel ratiometric fluorescent sensor based on chemical etching of gold nanocluster (GNCs) for label-free, separation-free determination of tris­(2-carboxyethyl)­phosphine (TCEP). TCEP was discovered to exhibit unusual chemical behavior toward fluorescent gold nanoclusters: it quenched the red fluorescent emission of the bovine serum album (BSA)-protected GNCs (GNCs@BSA) and simultaneously restored the blue fluorescent emission of the dityrosine (diTyr) residues of the BSA ligand. The TCEP-induced quenching of the fluorescent GNCs@BSA was investigated with the UV–vis adsorption spectrum, the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS), revealing the chemical etching of the gold(0) core of the GNCs@BSA by TCEP. Furthermore, the ratio of the blue fluorescence intensity of the diTyr to the red fluorescence intensity of the GNCs@BSA was found to be dependent on TCEP concentration and showed a linear relationship in the TCEP concentration range of 500 nM to 50, 000 nM (<i>R</i>² = 0.9943) with a limit of detection (LOD) of 130 nM, achieving the higher sensitivity over previous reports. This ratiometric sensor also showed superior selectivity for TCEP over certain common interferences including glutathione, 20 kinds of natural amino acids, and the oxidized form of TCEP. With the developed ratiometric method, the deproteinized human serum samples spiked with TCEP were analyzed with satisfactory results. In addition, it is worth noting that compared with conventional ratiometric fluorescent sensors, the ratiometric sensor developed in this study does not require external fluorophores, avoiding the additional derivation procedures

Hidden Dityrosine Residues in Protein-Protected Gold Nanoclusters

The protein ligand shells of fluorescent protein-protected gold nanoclusters play an important role in the physiochemical properties and sensing applications of the nanoclusters. Recently, more and more attention has been paid to the investigation of the changes in the protein structure elements induced by the introduction of the nanoclusters in the proteins. In this work, the strategy of removal of the encapsulated gold nanoclusters from the protein ligand cages has been proposed, producing the “hollow” (or possibly “imprinted”) proteins for investigations for the first time. Nontoxic cysteamine was used as the etchant of the gold nanoclusters. With bovine serum albumin, lysozyme, and ovalbumin as model proteins, it was found that the luminescent dityrosine cross-links exist in the protein-protected gold nanoclusters, however, inner filter effect caused by the gold nanoclusters hide them

Ion Permeability of Polydopamine Films Revealed Using a Prussian Blue-Based Electrochemical Method

Polydopamine (PDA) is fast becoming a popular surface modification technique. Detailed understanding of the ion permeability properties of PDA films will improve their applications. Herein, we report for the first time the thickness-independent ion permeability of PDA films using a Prussian blue (PB)-based electrochemical method. In this method, PDA films are deposited via ammonium persulfate-induced dopamine polymerization onto a PB electrode. The ion permeability of the PDA films can thus be detected by observing the changes in electrochemical behaviors of the PB coated by PDA films. On the basis of this method, it was unexpectedly found that the PDA films with thickness greater than 45 nm (e.g., ∼60 and ∼113 nm) can exhibit pH-switchable but thickness-insensitive permeability to monovalent cations such as potassium and sodium ions. These observations clearly indicate the presence of a continuous network of interconnected intermolecular voids within PDA films, regardless of film thickness

In Situ Synthesis of CuS Nanoparticle-Doped Poly(<i>N</i>‑isopropylacrylamide)-Based Microgels for Near-Infrared Triggered Photothermal Therapy

Poly­(<i>N</i>-isopropylacrylamide)-<i>co</i>-(acrylic acid) (pNIPAm-<i>co</i>-AAc) microgels incorporated with CuS nanoparticles (CuSNPs) were synthesized and employed for near-infrared (NIR) triggered photothermal killing of cancer cells. Cu²⁺ was enriched in the microgels through deprotonation of the pNIPAm-<i>co</i>-AAc microgels at high solution pH. CuSNPs were subsequently generated within the pNIPAm-<i>co</i>-AAc microgels upon exposure to heat and S^2–. The solution of hybrid microgels showed an absorption peak in the NIR region (∼1000 nm). After demonstrating that the hybrid microgels were not cytotoxic, we showed that NIR excitation of the hybrid microgels could be used to kill HeLa cells. Almost 90% of the HeLa cells were killed when incubated with 400 μg/mL of the hybrid microgels and exposed to 808 nm laser light with a power density of 2 W/cm² for 10 min. While these materials show promise for photothermal therapy, they can also be incorporated into a hydrogel matrix that can be triggered to release small molecule drugs upon exposure to NIR wavelengths

Data_Sheet_1_Transcutaneous electrical acupoint stimulation alleviates cerebral ischemic injury through the TLR4/MyD88/NF-κ B pathway.docx

This study was to explore whether transcutaneous electrical acupoint stimulation (TEAS) treatment could mediate inflammation, apoptosis, and pyroptosis of neuronal cells and microglia activation through the TLR4/MyD88/NF-κB pathway in the early stage of ischemic stroke. TEAS treatment at Baihui (GV20) and Hegu (LI4) acupoints of the affected limb was administered at 24, 48, and 72 h following middle cerebral artery occlusion/reperfusion (MCAO/R), with lasting for 30 min each time. Neurological impairment scores were assessed 2 h and 72 h after ischemia/reperfusion (I/R). TTC staining was used to evaluate the volume of brain infarction. The histopathologic changes of hippocampus were detected by H&E staining. WB analysis was performed to assess the levels of TLR4, MyD88, p-NF-κB p65/NF-κB p65, and inflammation, apoptosis, pyroptosis-related proteins. TLR4 expression was measured using immunohistochemistry. The expression of inflammation-related proteins was also measured using ELISA. Immunofluorescence was used to detect the expression level of Iba1. Our findings demonstrated that TEAS intervention after I/R improved neurological function, reduced the volume of brain infarction, and mitigated pathological damage. Moreover, TEAS reduced the levels of TLR4, MyD88, p-NF-κB p65/NF-κB p65, TNF-α, IL-6, Bax, NLRP3, cleaved caspase-1/pro caspase-1, IL-1β, IL-18, GSDMD, and Iba1 while enhancing Bcl-2 expression. Moreover, the protective effects of TEAS could be counteracted by lipopolysaccharide (LPS, a TLR4 agonist). In conclusion, TEAS can reduce cerebral damage and suppress inflammation, cell death, and microglia activation after ischemic stroke via inhibiting the TLR4/MyD88/NF-κB pathway.</p

Reactive Dynamics Simulation Study on the Pyrolysis of Polymer Precursors To Generate Amorphous Silicon Oxycarbide Structures

Amorphous silicon oxycarbide (SiOC) ceramics have extensive applications as structural and functional materials because of their unique properties. Preparation of SiOC from the pyrolysis of polymer precursors involves a complicated process of chemical reactions, various bond redistributions, and so on. With the aim to gain more insights into this and obtain a SiOC structure model, a series of molecular dynamics (MD) simulations integrated with a shell programming of gas removal scheme were implemented. Here, we chose hydridopolycarbosilane and polymethylhydrosiloxane as polymer precursors and constructed a rational polymer atomic model by using a reactive force field ReaxFF derived from elsewhere, which has been tested and verified to be applicable to our C/Si/H/O system. MD simulations of pyrolysis of the polymers indicated that H₂ and CH₄ were the major gas products, which were deleted through NVT-MD simulations along with the script code mimicking the experimental process. The atomic model of the dense SiOC was obtained after compression and further equilibration of the solid structure. The final SiOC structure was analyzed by computing its radial distribution function. It contains C–C, Si–O, Si–C, and Si–Si bonds, which agrees well with the experimental data. These results confirm the accuracy of the MD simulations and the atomic model of SiOC ceramics

Reactive Dynamics Simulation Study on the Pyrolysis of Polymer Precursors To Generate Amorphous Silicon Oxycarbide Structures

Amorphous silicon oxycarbide (SiOC) ceramics have extensive applications as structural and functional materials because of their unique properties. Preparation of SiOC from the pyrolysis of polymer precursors involves a complicated process of chemical reactions, various bond redistributions, and so on. With the aim to gain more insights into this and obtain a SiOC structure model, a series of molecular dynamics (MD) simulations integrated with a shell programming of gas removal scheme were implemented. Here, we chose hydridopolycarbosilane and polymethylhydrosiloxane as polymer precursors and constructed a rational polymer atomic model by using a reactive force field ReaxFF derived from elsewhere, which has been tested and verified to be applicable to our C/Si/H/O system. MD simulations of pyrolysis of the polymers indicated that H₂ and CH₄ were the major gas products, which were deleted through NVT-MD simulations along with the script code mimicking the experimental process. The atomic model of the dense SiOC was obtained after compression and further equilibration of the solid structure. The final SiOC structure was analyzed by computing its radial distribution function. It contains C–C, Si–O, Si–C, and Si–Si bonds, which agrees well with the experimental data. These results confirm the accuracy of the MD simulations and the atomic model of SiOC ceramics

Reactive Dynamics Simulation Study on the Pyrolysis of Polymer Precursors To Generate Amorphous Silicon Oxycarbide Structures

Amorphous silicon oxycarbide (SiOC) ceramics have extensive applications as structural and functional materials because of their unique properties. Preparation of SiOC from the pyrolysis of polymer precursors involves a complicated process of chemical reactions, various bond redistributions, and so on. With the aim to gain more insights into this and obtain a SiOC structure model, a series of molecular dynamics (MD) simulations integrated with a shell programming of gas removal scheme were implemented. Here, we chose hydridopolycarbosilane and polymethylhydrosiloxane as polymer precursors and constructed a rational polymer atomic model by using a reactive force field ReaxFF derived from elsewhere, which has been tested and verified to be applicable to our C/Si/H/O system. MD simulations of pyrolysis of the polymers indicated that H₂ and CH₄ were the major gas products, which were deleted through NVT-MD simulations along with the script code mimicking the experimental process. The atomic model of the dense SiOC was obtained after compression and further equilibration of the solid structure. The final SiOC structure was analyzed by computing its radial distribution function. It contains C–C, Si–O, Si–C, and Si–Si bonds, which agrees well with the experimental data. These results confirm the accuracy of the MD simulations and the atomic model of SiOC ceramics