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1.
J Nanosci Nanotechnol ; 20(2): 769-778, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383072

RESUMO

A super absorbent was synthesized from calcium-aluminum waste residue of aluminum industrial using a facile hydrothermal method. The XRD results revealed that the main phase of hydrothermal product at 120 °C is CaSO4 ·2H2O, with a small amount of Al(OH)3. The as-prepared products were used to investigate the adsorptive applications in Congo red (CR) removal, and the results showed that the products treated at 120 °C had the best adsorption properties. The maximum adsorption capacity reaches about 1860.11 mg/g with a removal rate of 99.75%. Furthermore, the used adsorbent could be regenerated for at least four cycles through a calcination procedure, indicating its potential as an excellent adsorbent for the removal of CR dye from wastewater. The adsorption behavior was analyzed by Langmuir, Freundlich and Sips isotherms, and the adsorption proved to be a multilayer adsorption. This facile method presented here may provide promise synthesis of high-effective and low-cost adsorbents from industrial solid waste and achieve the goal of "using waste to treat waste" in the future.

2.
Parasitol Res ; 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31486947

RESUMO

Neospora caninum is an apicomplexan parasite considered one of the main causes of abortion in cattle worldwide; thus, there is an urgent need to develop novel therapeutic agents to control the neosporosis. Enoyl acyl carrier protein reductase (ENR) is a key enzyme of the type II fatty acid synthesis pathway (FAS II), which is essential for apicomplexan parasite survival. The antimicrobial agent triclosan has been shown to be a very potent inhibitor of ENR. In this study, we identified an E. coli ENR-like protein in N. caninum. Multiple sequence alignment showed all the requisite features of ENR existed in this protein, so we named this protein NcENR. Swiss-Model analysis showed NcENR interacts with triclosan. We observed that ENR is localized in the apicoplast, a plastid-like organelle. Similar to the potent inhibition of triclosan on other apicomplexa parasites, this compound markedly inhibits the growth of N. caninum at low concentrations. Further research showed that triclosan attenuated the invasion ability and proliferation ability of N. caninum at low concentrations. The results from in vivo studies in the mouse showed that triclosan attenuated the virulence of N. caninum in mice mildly and reduced the parasite burden in the brain significantly. Taken together, triclosan inhibits the growth of N. caninum both in vitro and in vivo at low concentrations.

3.
Colloids Surf B Biointerfaces ; 183: 110457, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31476688

RESUMO

Bacterial cellulose (BC) has a role in tissue repair and regenerative medicine, which has already attracted tremendous interest from researchers, especially those working in the field of hybrid materials. Herein, we designed BC-based macroporous functional materials by dialdehyde bacterial cellulose (DBC) cross-linking with oligopeptides under mild reactive conditions. The interfacial properties of the surface modified BC were examined by biomimetic mineralization. The results showed that a macroporous structure was achieved by using oligopeptides as chemical cross-linking agents with an interconnected macroporosity ranging from 20 µm to 80 µm. Their mechanical properties were barely altered compared to the pristine BC. Their enhanced surface charges stemmed from the carboxyl groups of the oligopeptides engaging in reactions with amine and aldehyde groups. The oligopeptides cross-linked DBC showed a faster initial induction towards minerals via interfacial wettability resulting in promotion of mineralization, the hybrid materials had excellent biocompatibility relative to the pristine BC. These findings are vital to the development of other biopolymers with essential macroporous structures as well as improved interfacial wettability, which enables their possible uses in tissue repair and regenerative medicine.

4.
J Immunother Cancer ; 7(1): 231, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462297

RESUMO

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) are immunosuppressive cells that play an important role in immune evasion, PD-1/PD-L1 inhibitor tolerance and tumour progression. Therefore, MDSCs are potential targets for cancer immunotherapy. In this study, we screened an effective polymorphonuclear MDSC (PMN-MDSC) inhibitor from the Traditional Chinese Medicine Library and evaluated its synergistic antitumour effects with PD-1 inhibitor. METHODS: In the present study, we found that PMN-MDSCs accumulate heavily in the spleen and bone marrow of melanoma (B16-F10) tumour-bearing mice. Then, we determined the top 10 key proteins in the upregulated KEGG pathways of PMN-MDSCs in tumour-bearing mice through proteomics and Cytoscape analysis. The key proteins were then used as targets for the screening of PMN-MDSC inhibitors from the traditional Chinese Medicine Library (20000 compounds) through molecular docking and weight calculation of the docking score. Finally, the inhibitory effect of the inhibitor was verified through proteomics and metabolomics analysis in vitro and melanoma (B16-F10) and triple-negative breast cancer (4 T1) mouse tumour models in vivo. RESULTS: Traditional Chinese medicine saposhnikovia root extract Prim-O-glucosylcimifugin (POG) could bind well to the target proteins and inhibit the proliferation, metabolism and immunosuppressive ability of PMN-MDSCs by inhibiting arginine metabolism and the tricarboxylic acid cycle (TCA cycle). POG could also increase CD8 T-lymphocyte infiltration in the tumours and enhance the antitumour effect of PD-1 inhibitor in B16-F10 and 4 T1 mouse tumour models. CONCLUSIONS: POG was successfully screened from the traditional Chinese Medicine library as a PMN-MDSC inhibitor. POG exhibited a good synergistic antitumour effect with PD-1 inhibitor. This study provided a potential option for enhancing the efficacy of PD-1 inhibitors in clinical applications.

5.
Nanotechnology ; 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31469106

RESUMO

In this study, we employed microwave plasma assisted reduction (MPAR) method for preparing metallic nanoparticles with desirable morphology. Compared with hydrogen thermal reduction technique, MPAR technique could greatly maintain the original morphology of self-sacrificing precursors, as well as is proved to be high-efficiency, energy-saving and pollution-free. Taking ferromagnetic metallic Co as forerunner, Co nanosheets with inerratic hexagonal morphology were successfully synthesized on a large scale uniformly. The lateral dimension of achieved Co nanosheets is in the range of 3~5 µm with tens of nanometers in thickness. The intact hexagonal flaky shape of Co nanosheets is beneficial for improving dielectric loss by increasing electric channels and interfacial polarization. Consequently, the minimum reflection loss could reach up to -71 dB at a thin thickness of 1.2 mm. Furthermore, the effective bandwidth (RL﹤-10 dB) could be achieved in a wide range of 2.8~18 GHz by integrating the thickness from 5.0~1.0 mm, which provide the possible for applications in electromagnetic shielding and radar stealth fields. It is believed that MPAR technique is suitable for designing and preparing novel microwave absorbers on the basis of appropriate precursors, providing new opportunities for acquiring high performance microwave absorbers in the future.

6.
Int J Mol Sci ; 20(16)2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398909

RESUMO

High temperatures seriously limit plant growth and productivity. Investigating heat-responsive molecular mechanisms is important for breeding heat-tolerant crops. In this study, heat-responsive mechanisms in leaves from a heat-sensitive spinach (Spinacia oleracea L.) variety Sp73 were investigated using two-dimensional gel electrophoresis (2DE)-based and isobaric tags for relative and absolute quantification (iTRAQ)-based proteomics approaches. In total, 257 heat-responsive proteins were identified in the spinach leaves. The abundance patterns of these proteins indicated that the photosynthesis process was inhibited, reactive oxygen species (ROS) scavenging pathways were initiated, and protein synthesis and turnover, carbohydrate and amino acid metabolism were promoted in the spinach Sp73 in response to high temperature. By comparing this with our previous results in the heat-tolerant spinach variety Sp75, we found that heat inhibited photosynthesis, as well as heat-enhanced ROS scavenging, stress defense pathways, carbohydrate and energy metabolism, and protein folding and turnover constituting a conservative strategy for spinach in response to heat stress. However, the heat-decreased biosynthesis of chlorophyll and carotenoid as well as soluble sugar content in the variety Sp73 was quite different from that in the variety Sp75, leading to a lower capability for photosynthetic adaptation and osmotic homeostasis in Sp73 under heat stress. Moreover, the heat-reduced activities of SOD and other heat-activated antioxidant enzymes in the heat-sensitive variety Sp73 were also different from the heat-tolerant variety Sp75, implying that the ROS scavenging strategy is critical for heat tolerance.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31462044

RESUMO

Because of their fascinating properties, two-dimensional (2D) nanomaterials have attracted a lot of attention for developing next-generation electronics and optoelectronics. However, there is still a lack of cost-effective, highly reproducible, and controllable synthesis methods for developing high-quality semiconducting 2D monolayers with a sufficiently large single-domain size. Here, utilizing a NaOH promoter and W foils as the W source, we have successfully achieved the fabrication of ultralarge single-domain monolayer WS2 films via a modified chemical vapor deposition method. With the proper introduction of a NaOH promoter, the single-domain size of monolayer WS2 can be increased to 550 µm, while the WS2 flakes can be well controlled by simply varying the growth duration and oxygen concentration in the carrier gas. Importantly, when they are fabricated into global backgated transistors, WS2 devices exhibit respectable peak electron mobility up to 1.21 cm2 V-1 s-1, which is comparable to those of many state-of-the-art WS2 transistors. Photodetectors based on these single-domain WS2 monolayers give an impressive photodetection performance with a maximum responsivity of 3.2 mA W-1. All these findings do not only provide a cost-effective platform for the synthesis of high-quality large single-domain 2D nanomaterials, but also facilitate their excellent intrinsic material properties for the next-generation electronic and optoelectronic devices.

8.
Anal Chim Acta ; 1080: 170-177, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31409467

RESUMO

A sensitive nanocomplex probe prepared from fluorescent polydopamine nanoparticles (F-PDA) and cobalt oxyhydroxide (CoOOH) nanosheets was established for the determination of α-glucosidase activity. In this detection system, the fluorescence of F-PDA was firstly quenched by CoOOH nanosheets based on fluorescence resonance energy transfer (FRET). Subsequently, ascorbic acid was produced from 2-O-α-d-glucopyranosyl-l-ascorbic acid which was selectively hydrolyzed by α-glucosidase. CoOOH was reduced to Co2+ by the released ascorbic acid, which resulted in the recovery of F-PDA nanoparticles fluorescence. In consequence, α-glucosidase activity was determined by the fluorescence recovery degree of the F-PDA nanoparticle. This fluorescent method showed a good linear relationship with the activity of α-glucosidase from 2 to 80 U L-1 and low detection limit of 1.65 U L-1 (S/N = 3). This fluorescence probe with high selectivity and sensitivity demonstrated a remarkable applicability in human serum samples and provided an alternative for α-glucosidase inhibitors screening in the discovery of anti-diabetes drugs.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31433101

RESUMO

An electrochemical protocol has been developed to achieve arylation of electron-deficient arenes through reductive activation. Various electro-deficient arenes and aryl diazonium tetrafluoroborate have been examined in this transformation under the conditions of undivided cell, providing the desired products up to 92% yield. Instead of preparing diazonium reagents, these reactions could also be carried from anilines in a one-pot fashion. EPR studies supported that the cathodic reduction of quinoxaline occurred in this transformation. At the same time, cyclic voltammetry indicated that both quinoxaline and aryl diazonium salt had relatively low reduction potential, which suggested that they could be activated through reduction in the reaction.

10.
J Agric Food Chem ; 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31365242

RESUMO

High-performance and useful graphene oxide (GO) and cellulose nanocrystals (CNCs) are easily extracted from natural graphite and cellulose raw materials, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is produced by bacterial fermentation from natural plant corn stalks, etc. In this study, novel ternary nanocomposites consisting of PHBV/cellulose nanocrystal-graphene oxide nanohybrids were prepared via a simple solution casting method. The synergistic effect of CNC with GO nanohybrids obtained by chemical grafting (CNC-GO, covalent bonds) and physical blending (CNC/GO, noncovalent bonds) on the physicochemical properties of PHBV nanocomposites was evaluated and the results compared with a single component nanofiller (CNC or GO) in binary nanocomposites. More interestingly, ternary nanocomposites displayed the highest thermal stability and mechanical properties. Compared to neat PHBV, the tensile strength and elongation to break increased by 170.2 and 52.1%, respectively, and maximum degradation temperature (Tmax) increment by 26.3 °C, were observed for the ternary nanocomposite with 1 wt % covalent bonded CNC-GO. Compared to neat PHBV, binary, and 1:0.5 wt % noncovalent CNC/GO based nanocomposites, the ternary nanocomposites with 1 wt % covalent bonded CNC-GO exhibited excellent barrier properties, good antibacterial activity (antibacterial ratio of 100.0%), reduced barrier properties, and lower migration level for both food simulants. Such a synergistic effect yielded high-performance ternary nanocomposites with great potential for bioactive food packaging materials.

11.
ACS Nano ; 13(8): 9431-9441, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31386338

RESUMO

Graphene has been the subject of widespread research during the past decade because of its outstanding physical properties which make it an ideal nanoscale material to investigate fundamental properties. Such characteristics promote graphene as a functional material for the emergence of disruptive technologies. However, to impact daily life products and devices, high-quality graphene needs to be produced in large quantities using an environmentally friendly protocol. In this context, the production of graphene which preserves its outstanding electronic properties using a green chemistry approach remains a key challenge. Herein, we report the efficient production of electrode material for micro-supercapacitors obtained by functionalization of water-dispersed high-quality graphene nanosheets with polydopamine. High-frequency (terahertz) conductivity measurements of the graphene nanosheets reveal high charge carrier mobility up to 1000 cm-2 V-1 s-1. The fine water dispersibility enables versatile functionalization of graphene, as demonstrated by the pseudocapacitive polydopamine coating of graphene nanosheets. The polydopamine functionalization causes a modest, i.e., 20%, reduction of charge carrier mobility. Thin film electrodes based on such hybrid materials for micro-supercapacitors exhibit excellent electrochemical performance, namely a volumetric capacitance of 340 F cm-3 and a power density of 1000 W cm-3, thus outperforming most of the reported graphene-based micro-supercapacitors. These results highlight the potential for water-dispersed, high-quality graphene nanosheets as a platform material for energy-storage applications.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31449726

RESUMO

With perovskite-based solar cells (PSCs) now reaching efficiencies >20%, the stability of PSCs devices has become a critical challenge for commercialization. However, most efficient hole-transporting materials (HTMs) thus far still rely on the state-of-the-art methoxy triphenylamine (MOTPA) donor unit in which methoxy groups usually reduce the device stability. Herein, a carbazole-fluorene hybrid has been employed as methoxy-free donor to construct organic HTMs. The indeno[1,2-b]carbazole group not only inherits the characteristics of carbazole and fluorene, but also exhibits additional advantages arising from bulky planar structure. Consequently, M129 endowed with indeno[1,2-b]carbazole simultaneously exhibits a promising efficiency of over 20% and superior long-term stability. The hybrid strategy toward the methoxy-free donor opens a new avenue for developing efficient and stable HTMs.

13.
Proc Natl Acad Sci U S A ; 116(33): 16641-16650, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31363048

RESUMO

Active DNA demethylation is critical for controlling the DNA methylomes in plants and mammals. However, little is known about how DNA demethylases are recruited to target loci, and the involvement of chromatin marks in this process. Here, we identify 2 components of the SWR1 chromatin-remodeling complex, PIE1 and ARP6, as required for ROS1-mediated DNA demethylation, and discover 2 SWR1-associated bromodomain-containing proteins, AtMBD9 and nuclear protein X1 (NPX1). AtMBD9 and NPX1 recognize histone acetylation marks established by increased DNA methylation 1 (IDM1), a known regulator of DNA demethylation, redundantly facilitating H2A.Z deposition at IDM1 target loci. We show that at some genomic regions, H2A.Z and DNA methylation marks coexist, and H2A.Z physically interacts with ROS1 to regulate DNA demethylation and antisilencing. Our results unveil a mechanism through which DNA demethylases can be recruited to specific target loci exhibiting particular histone marks, providing a conceptual framework to understand how chromatin marks regulate DNA demethylation.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31407271

RESUMO

The potential for physicochemical driving forces facilitating topical transport of the lipid-soluble drug oxaprozin (OXA) was investigated using surface-enhanced Raman spectroscopy (SERS) in this study. Azone, iontophoresis (IP), and sonophoresis (SP) were combined and performed on mouse skin for the OXA transdermal penetration, and the synergistic effect was analyzed using Raman spectroscopy. The data of characteristic peak intensity were processed with overlapping peak resolving and standard normalization. The results showed that Azone promoted the transdermal penetration of OXA (5.9-fold greater than the OXA concentration of normal penetration); SP enhanced OXA transdermal penetration (5.5-fold); IP enhanced OXA transdermal penetration (4.2-fold); the combined application of Azone and SP (Azone+SP) and SP+IP can improve the enhancement coefficient of OXA transdermal penetration (8.4-fold and 6.1-fold, > 5.9, > 5.5, > 4.2), and their combined application has a synergistic effect; Azone+IP does not have a synergistic effect while the enhancement coefficient of Azone+IP (5.3-fold, < 5.9) and Azone+SP+IP (7.2-fold, < 8.4) was slightly reduced. As for the drug OXA, Azone+SP is an effective method of transdermal penetration.

15.
Alzheimers Dement ; 15(8): 1071-1080, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31422798

RESUMO

INTRODUCTION: Neuronal-derived exosomal Aß42, T-tau, and P-T181-tau have been demonstrated to be biomarkers of Alzheimer's disease (AD). However, no study has assessed the association of Aß42, T-tau, and P-T181-tau between exosomes and CSF. METHODS: This was a multicenter study with two-stage design. The subjects included 28 AD patients, 25 aMCI patients, and 29 controls in the discovery stage; the results of which were confirmed in the validation stage (73 AD, 71 aMCI, and 72 controls). RESULTS: The exosomal concentrations of Aß42, T-tau, and P-T181-tau in AD group were higher than those in aMCI and control groups (all P < .001). The level of each exosomal biomarker was highly correlated with that in CSF. DISCUSSION: This study verified the agreement between CSF and blood exosomal biomarkers and confirmed that exosomal Aß42, T-tau, and P-T181-tau have the same capacity as those in CSF for the diagnosis of AD and aMCI.

17.
Plant Biotechnol J ; 2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31301098

RESUMO

Small signalling peptides, generated from larger protein precursors, are important components to orchestrate various plant processes such as development and immune responses. However, small signalling peptides involved in plant immunity remain largely unknown. Here, we developed a pipeline using transcriptomics- and proteomics-based screening to identify putative precursors of small signalling peptides: small secreted proteins (SSPs) in rice, induced by rice blast fungus Magnaporthe oryzae and its elicitor, chitin. We identified 236 SSPs including members of two known small signalling peptide families, namely rapid alkalinization factors and phytosulfokines, as well as many other protein families that are known to be involved in immunity, such as proteinase inhibitors and pathogenesis-related protein families. We also isolated 52 unannotated SSPs and among them, we found one gene which we named immune response peptide (IRP) that appeared to encode the precursor of a small signalling peptide regulating rice immunity. In rice suspension cells, the expression of IRP was induced by bacterial peptidoglycan and fungal chitin. Overexpression of IRP enhanced the expression of a defence gene, PAL1 and induced the activation of the MAPKs in rice suspension cells. Moreover, the IRP protein level increased in suspension cell medium after chitin treatment. Collectively, we established a simple and efficient pipeline to discover SSP candidates that probably play important roles in rice immunity and identified 52 unannotated SSPs that may be useful for further elucidation of rice immunity. Our method can be applied to identify SSPs that are involved not only in immunity but also in other plant functions.

18.
Org Lett ; 21(14): 5438-5442, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31267756

RESUMO

Imidodiphosphoric acids were employed to catalyze inverse-electron-demand hetero-Diels-Alder reaction of ß,γ-unsaturated α-ketoesters and 3-vinylindoles. A series of optically active 3,4-dihydro-2H-pyran derivatives with three contiguous stereogenic centers was synthesized in excellent yields (70-99%), diastereoselectivities (>20:1), and enantioselectivities (73-99%). The resulting indole containing 3,4-dihydro-2H-pyran could be converted to tetrahydropyran derivatives, which appear in several biological active compounds by simple hydrogenation reduction.

19.
ChemSusChem ; 12(16): 3778-3784, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31278839

RESUMO

Lactams are privileged in bioactive natural products and pharmaceutical agents and widely featured in functional materials. This study presents a novel versatile approach to the direct synthesis of lactams from oxocarboxylic acids without catalyst or external hydrogen. The method involves the in situ release of formic acid from formamides induced by water to facilitate efficient cycloamination. Water also suppresses the formation of byproducts. This unconventional pathway is elucidated by a combination of model experiments and density functional theory calculations, whereby cyclic imines (5-methyl-3,4-dihydro-2-pyrrolone and its tautomeric structures) are found to be favorable intermediates toward lactam formation, in contrast to the conventional approach encompassing cascade reductive amination and cyclization. This sustainable and simple protocol is broadly applicable for the efficient production of various N-unsubstituted and N-substituted lactams.

20.
Angew Chem Int Ed Engl ; 58(35): 12070-12075, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31259482

RESUMO

Suppressing the mobility of anionic species in polymer electrolytes (PEs) is essential for mitigating the concentration gradient and internal cell polarization, and thereby improving the stability and cycle life of rechargeable alkali metal batteries. Now, an ether-functionalized anion (EFA) is used as a counter-charge in a lithium salt. As the salt component in PEs, it achieves low anionic diffusivity but sufficient Li-ion conductivity. The ethylene oxide unit in EFA endows nanosized self-agglomeration of anions and trapping interactions between the anions and its structurally homologous matrix, poly(ethylene oxide), thus suppressing the mobility of negative charges. In contrast to previous strategies of using anion traps or tethering anions to a polymer/inorganic backbone, this work offers a facile and elegant methodology on accessing selective and efficient Li-ion transport in PEs and related electrolyte materials (for example, composites and hybrid electrolytes).

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