Publications by authors named "Jinshan Li"

77 Publications

HFIP-Promoted Selective Hydroxyalkylation of Aniline Derivatives with Arylglyoxal Hydrates.

J Org Chem 2022 May 25;87(9):6352-6361. Epub 2022 Apr 25.

Collaborative Innovation Center for Advanced Organic Chemical Materials Co-Constructed by the Province and Ministry, Hubei University, Wuhan 430062, PR China.

A HFIP-promoted highly selective hydroxyalkylation of aniline derivatives with arylglyoxal hydrates has been realized. The reaction produces various ,-dialkylanilines and their derivatives with α-hydroxy carbonyl units in good to excellent yields under mild conditions. Furthermore, the synthetic potential of this method has been demonstrated by the facile synthesis of several structurally interesting molecules such as benzil, 1,2,4-triazine, quinoxaline, hydantoin, and 2-thiohydantoin with aromatic amine units.
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http://dx.doi.org/10.1021/acs.joc.1c03155DOI Listing
May 2022

Divergent Synthesis of -Difluorinated Oxa-Spirocyclohexadienones by One-Pot Sequential Reactions of -Hydroxybenzyl Alcohols with Difluoroenoxysilanes.

Org Lett 2022 Apr 28;24(13):2488-2493. Epub 2022 Mar 28.

Advanced Research Institute and Department of Chemistry, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China.

A new efficient formal [2 + 3] cyclization of -hydroxybenzyl alcohols with difluoroenoxysilanes has been established. This convenient one-pot sequential procedure enables the divergent construction of highly functionalized -difluorinated oxa-spirocyclohexadienones under mild conditions. As opposed to the common C1 synthons in previous studies, difluoroenoxysilanes acted as new 3-atom (CCO) synthons for the first time here. The AcOH and HO generated in the reaction are critical for the reactions to proceed smoothly.
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http://dx.doi.org/10.1021/acs.orglett.2c00550DOI Listing
April 2022

Accelerated discovery of thermostable high-energy materials with intramolecular donor-acceptor building blocks.

Chem Commun (Camb) 2022 Apr 5;58(28):4460-4463. Epub 2022 Apr 5.

Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China.

A domain-related data search promoted triazolotriazine-fused energetic scaffold filtration with combinatorial design to alleviate the lack of thermostable high-energy materials; 16 candidates were discovered that may show promising energy and safety performance, as well as excellent thermal stability. Novel fused triazolo-1,2,4-triazine energetic material 7-nitro-3-(1-tetrazol-5-yl)-[1,2,4]triazolo[5,1-][1,2,4]triazin-4-amine-2-oxide (Candidate No. 4) with excellent thermal stability, high energy performance and low sensitivity was developed successfully by using a facile N-oxide synthetic method. Our findings may be applicable to a wider range of materials and prove equally powerful for searching for other high-performing energetic materials.
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http://dx.doi.org/10.1039/d2cc00074aDOI Listing
April 2022

Synthesis of 2,2-Difluoro-3-hydroxy-1,4-diketones via an HFIP-Catalyzed Mukaiyama Aldol Reaction of Glyoxal Monohydrates with Difluoroenoxysilanes.

J Org Chem 2022 01 7;87(2):1144-1153. Epub 2022 Jan 7.

Collaborative Innovation Center for Advanced Organic Chemical Materials Co-Constructed by the Province and Ministry, Hubei University, Wuhan 430062, P.R. China.

A novel efficient HFIP-catalyzed synthesis of structurally diverse 2,2-difluoro-3-hydroxy-1,4-diketone derivatives from readily available glyoxal monohydrates and difluoroenoxysilanes is described. This convenient protocol is induced by the distinctive fluorine effect of the reactants and the fluoroalcohol catalyst, which represents the first application of fluoroalcohol catalysis in a Mukaiyama aldol reaction.
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http://dx.doi.org/10.1021/acs.joc.1c02504DOI Listing
January 2022

Cascade Cyclization of Azadienes with Difluoroenoxysilanes: A One-Pot Formal [4 + 2] Approach to Fluorinated Polyfused Heterocycles.

Org Lett 2021 12 3;23(24):9526-9532. Epub 2021 Dec 3.

Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China.

A TfOH-promoted synthesis of fluorinated polyfused heterocycles via the cascade cyclization of azadienes and difluoroenoxysilanes has been developed, leading to the facile construction of fluorinated benzofuro[3,2-]pyridines, 5-indeno[1,2-]pyridines, and 5,6-dihydrobenzo[]quinolines. This one-pot formal [4 + 2] approach involves 1,4-difluoroalkylation, desulfonylation, cyclization, and dehydrated and dehydrofluorinated aromatization and represents the first application of difluoroenoxysilane in cascade transformations. Furthermore, this methodology is highlighted by the synthesis of three fluoro analogues of bioactive molecules with potent topoisomerase inhibitory activities.
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http://dx.doi.org/10.1021/acs.orglett.1c03745DOI Listing
December 2021

Efficient mutagenesis targeting the gene in mice using a combination of Cas9 protein and dual gRNAs.

Am J Transl Res 2021 15;13(10):12094-12106. Epub 2021 Oct 15.

Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University Nanjing 210046, Jiangsu, China.

We injected mouse zygotes with combinations of Cas9 protein, mRNA, and two gRNAs targeting a single exon of type I interferon receptor () to determine the gene targeting efficiencies. Cas9 protein produced on-target mutations more efficiently than mRNA when each was used with a single gRNA, regardless of which gRNA was used. When mRNA and Cas9 protein were co-injected, the on-target efficiency could reach 97.0% when both gRNAs were used, which was higher than when either gRNA was used alone (61.3% and 75.5%, respectively; P<0.05). Co-injection of Cas9 protein with both gRNAs produced the highest on-target mutation rate of any combination (100.0%). Most on-target mutations were deletions of 2 to 113 nucleotides, and there were few off-target mutations in mutant animals. The expression intensity of IFNAR1 was reduced in heterozygous mice (IF) and almost or completely absent in homozygous null mice compared with that in wild-type mice (IF and Western blot). When both gRNAs targeting were used simultaneously with two gRNAs targeting , the on-target editing efficiency on each gene was 96.8% and 85.5%, respectively. Co-injection of dual gRNAs and Cas9 protein is an efficient approach for knockout and multi-gene editing in mice and may be applied in other animal models and breeding livestock.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8581890PMC
October 2021

Lattice distortion-enhanced superlubricity of (Mo, X)S (X = Al, Ti, Cr and V) with moiré superlattice.

Nanoscale 2021 Oct 8;13(38):16234-16243. Epub 2021 Oct 8.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, China.

Two-dimensional (2D) materials with the advantage of low interlayer shear strain are ultilized as lubricants in aerospace and precision manufacturing. Moiré superlattices (MSL), with attractive physical properties of electronic structures, interlayer hybridization and atomic forces, have been widely investigated in superlubricity, which is caused by elimination of interlayer lock-in by incommensurate atomic reconstruction. Although the foundations of superlubricity and the development of 2D lubricants vanishing friction have been investigated, it is still important to comprehensively reveal the influence of MSL on the interlayer van der Waals (vdW) interactions of 2D lubricants. Here, the contributions of lattice distortions of solute-doped twisted bilayers (Mo, X)S (X = Al, Ti, V and Cr) to superlubricity are comprehensively investigated by high-throughput modelling and DFT-D2 calculations. It is revealed that the lattice distortion not only breaks the interlayer balance of repulsion and van der Waals interactions but also yields layer corrugation. These layer-corrugation-induced changes of the interlayer interactions and spacing distances are utilized to optimize lubricity, which matches with the experimental friction coefficients in the order of (Mo, Al)S > (Mo, Cr)S > MoS >(Mo, V)S >(Mo, Ti)S. The evolutions of the band structures show an exponential relationship of the band edge width and layer deformations, paving a path to accelerate the development of advanced superlubricity materials lattice distortions.
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http://dx.doi.org/10.1039/d1nr02382aDOI Listing
October 2021

Thermal Processing Map and Microstructure Evolution of Inconel 625 Alloy Sheet Based on Plane Strain Compression Deformation.

Materials (Basel) 2021 Sep 3;14(17). Epub 2021 Sep 3.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China.

Plane strain compression tests were used to study the deformation behavior of an Inconel 625 alloy sheet at various temperatures and strain rates. The peak stress was selected to establish the constitutive equation, and the processing maps under different strains were drawn. The results show that the effective stress-strain curve of Inconel 625 has typical dynamic recrystallization (DRX) characteristics. With the increasing deformation temperature and the decreasing strain rate, the softening effect is significantly enhanced. The parameters of the constitutive equation are calculated, and the average error of the constitutive equation is 5.68%. Through the analysis of the processing map, a deformation temperature of 950-960 °C with a strain rate of 0.007-0.05 s were determined as the unstable region, and obvious local plastic-rheological zones were found in the unstable region. The optimum deformation condition was found to be 1020-1060 °C/0.005-0.03 s. Through electron backscattered diffraction (EBSD) characterization, it was found that both the increase of temperature and the decrease of strain rate significantly promote the recrystallization process. At a low strain rate, the main recrystallization mechanism is discontinuous dynamic recrystallization (DDRX). It is expected that the above results can provide references for the optimization of the rolling process and microstructure control of an Inconel 625 alloy sheet.
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http://dx.doi.org/10.3390/ma14175059DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8433832PMC
September 2021

The Localized Corrosion and Stress Corrosion Cracking of a 6005A-T6 Extrusion Profile.

Materials (Basel) 2021 Aug 30;14(17). Epub 2021 Aug 30.

State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China.

In the present work, the localized corrosion and stress corrosion cracking (SCC) behaviors of a commercial 6005A-T6 aluminum extrusion profile was studied comprehensively. The velocity of crack growth in self-stressed double-cantilever beam (DCB) specimens under constant displacement was estimated, which also provides insight into the local microstructure evolutions at the crack tips caused by the localized pitting corrosion, intergranular corrosion (IGC), and intergranular SCC. Characterizations of local corrosion along the cracking path for a period of exposure to 3.5% NaCl were revealed via optical microscope (OM), scanning electron microscope (SEM), and electron backscatter diffraction (EBSD). The typical features of the pits dominated by the distribution of precipitates included the peripheral dissolution of the Al matrix, channeling corrosion, intergranular attack, and large pits in the grains. The discontinuous cracking at the crack tips indicated the hydrogen-embrittlement-mediated mechanism. Moreover, the local regions enriched with MgSi and MgSi phases and with low-angle grain boundaries presented better SCC resistance than those of the matrix with high-angle grain boundaries, supporting a strategy to develop advanced Al-Mg-Si alloys via interfacial engineering.
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http://dx.doi.org/10.3390/ma14174924DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8434543PMC
August 2021

HFIP-Catalyzed Difluoroalkylation of Propargylic Alcohols to Access Tetrasubstituted Difluoroalkyl Allenes.

Org Lett 2021 Sep 27;23(18):7264-7269. Epub 2021 Aug 27.

Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China.

A hexafluoroisopropanol (HFIP)-catalyzed difluoroalkylation of propargylic alcohols with difluoroenoxysilanes to access structurally diverse tetrasubstituted difluoroalkyl allenes has been developed. This convenient procedure enables the rapid construction of highly functionalized multisubstituted fluorinated allenes in a mild and straightforward way. Furthermore, the synthetic potential of this methodology has been demonstrated by the facile synthesis of various structurally interesting fluorine-containing molecules such as -difluorosubstituted dihydropyran, tetrasubstituted CFH-allene, and multisubstituted fluorinated cyclopentanone derivatives.
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http://dx.doi.org/10.1021/acs.orglett.1c02659DOI Listing
September 2021

Reversal of Regioselectivity in Nucleophilic Difluoroalkylation of α,β-Enones Employing In Situ-Formed Sterically Encumbered Silylium Catalyst.

Org Lett 2021 Aug 20;23(15):5859-5864. Epub 2021 Jul 20.

Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China.

An efficient approach for the reversal of regioselectivity in the nucleophilic introduction of difluorinated carbanion into α,β-enones has been developed via a silylium catalysis. The strong electron-withdrawing properties and bulky substituents of in situ-generated silyl triflic imide catalyst is the key for the 1,4-addition reaction to proceed smoothly. The synthetic utility is highlighted by the further use of this method for the synthesis of 2,4,6-triarylsubstituted 3-fluoropyridines in a one-pot manner.
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http://dx.doi.org/10.1021/acs.orglett.1c01993DOI Listing
August 2021

Effect of High Strain Rate on Adiabatic Shearing of α+β Dual-Phase Ti Alloy.

Materials (Basel) 2021 Apr 19;14(8). Epub 2021 Apr 19.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China.

In the present work, the localized features of adiabatic shear bands (ASBs) of our recently designed damage tolerance α+β dual-phase Ti alloy are investigated by the integration of electron backscattering diffraction and experimental and theoretical Schmid factor analysis. At the strain rate of 1.8 × 10 s induced by a split Hopkinson pressure bar, the shear stress reaches a maximum of 1951 MPa with the shear strain of 1.27. It is found that the α+β dual-phase colony structures mediate the extensive plastic deformations along α/β phase boundaries, contributing to the formations of ASBs, microvoids, and cracks, and resulting in stable and unstable softening behaviors. Moreover, the dynamic recrystallization yields the dispersion of a great amount of fine α grains along the shearing paths and in the ASBs, promoting the softening and shear localization. On the contrary, low-angle grain boundaries present good resistance to the formation of cracks and the thermal softening, while the non-basal slipping dramatically contributes to the strain hardening, supporting the promising approaches to fabricate the advanced damage tolerance dual-phase Ti alloy.
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http://dx.doi.org/10.3390/ma14082044DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8073931PMC
April 2021

Influence of Isothermal ω Transitional Phase-Assisted Phase Transition From β to α on Room-Temperature Mechanical Performance of a Meta-Stable β Titanium Alloy Ti-10Mo-6Zr-4Sn-3Nb (Ti-B12) for Medical Application.

Front Bioeng Biotechnol 2020 20;8:626665. Epub 2021 Jan 20.

Institute of Advanced Wear and Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, China.

The microstructural evolution and tensile performance of a meta-stable β-type biomedical Ti-10Mo-6Zr-4Sn-3Nb (Ti-B12) alloy subjected to one-stage aging (OSA) and two-stage aging (TSA) are investigated in this work. The OSA treatment is performed at 510°C for 8 h. The TSA treatments are composed of low-temperature aging and high-temperature aging. In the first step, low-temperature aging is conducted at 325°C for 2 h. In the second step, the aging temperature is the same as that in the OSA. The result of the microstructure evolution shows that the precipitated secondary phase after aging is mainly influenced by the process of phase transition. There is a marked difference in the microstructure of the Ti-B12 alloy subjected to the OSA and TSA treatments. The needle-shaped α phases are precipitated in the parent β phase after the OSA treatment. Conversely, the short shuttle-like α phases precipitated after the TSA treatment are formed in the β matrix with the aid of the role of the isothermal ω transitional phase-assisted phase transition. The electron backscattered diffraction results indicate that the crystallographic orientation relationship of the α phases precipitated during the TSA treatment is basically analogous to those in the OSA treatment. The relatively higher tensile strength of 1,275 MPa is achieved by strengthening the effect of the short shuttle-like α precipitation with a size of 0.123 μm in length during the TSA treatment, associating with a suitable elongation of 12% at room temperature simultaneously. The fracture surfaces of the samples after the OSA and TSA treatments indicate that preventing the coarsening of the α layers in the grain boundaries is favorable for the enhancement of strength of Ti-B12 at room temperature. MTT test was carried out to evaluate the acute cytotoxicity and biocompatibility of the implanted material using L929 cells. The relative proliferation rates of cytotoxicity levels 0, 1, 2, 3, and 4 are ≥100, 80-99, 50-79, 30-49, and 0-29%, respectively. The cytotoxicity of the Ti-B12 alloy is slightly better than that of the Ti-6Al-4V alloy, which can meet the requirements of medical materials for biomedical materials.
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http://dx.doi.org/10.3389/fbioe.2020.626665DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7855458PMC
January 2021

Methyl-CpG-binding domain 3 (Mbd3) is an important regulator for apoptosis in mouse embryonic stem cells.

Am J Transl Res 2020 15;12(12):8147-8161. Epub 2020 Dec 15.

Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University Nanjing 210046, PR China.

Methyl-CpG-binding domain 3 (Mbd3) is a core repressor complex component. Although Mbd3 is required for the pluripotency of embryonic stem cells (ES), the role of Mbd3 in mouse ES (mES) cell apoptosis remains undefined. In this study naïve-state mES were derived and maintained in the presence of a selective protein kinase C pathway inhibitor (PKCi; Gӧ6983) to study the function of Mbd3 during mES apoptosis. Mbd3 overexpression in mES decreased the total cell number and viability, and it also dramatically increased the rate of apoptosis. Further investigation of Mbd3 overexpression revealed a 3-fold increase in the proapoptotic/prosurvival protein ratio (Bax/Bcl-2) and elevated RNA expression levels of apoptosis-related genes, including , and , with reduced RNA expression levels. Removal of PKCi from the mES cell culture resulted in upregulated Mbd3 expression and apoptosis, similar to the effects of Mbd3 overexpression. Furthermore, specific knockdown of endogenous Mbd3 partially rescued the mES apoptosis induced by the removal of PKCi, thus increasing the total cell number and viability while decreasing the rate of apoptosis. Additionally, , and RNA expression levels were partially reduced, and that of was partially increased. Our findings support Mbd3 as a pivotal regulator of apoptosis in mES.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7791517PMC
December 2020

HFIP-catalyzed direct dehydroxydifluoroalkylation of benzylic and allylic alcohols with difluoroenoxysilanes.

Chem Commun (Camb) 2021 Feb;57(8):1050-1053

Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China.

Hexafluoroisopropanol (HFIP)-catalyzed direct dehydroxydifluoroalkylation of benzylic and allylic alcohols with difluoroenoxysilanes is developed. This procedure enables the synthesis of a broad range of α,α-difluoroketones, a class of highly valuable intermediates and building blocks in medicinal and organic chemistry. Here, we have demonstrated for the first time that HFIP could act as a powerful catalyst for fluorinated carbon-carbon bond formation. The application of this protocol in late-stage dehydroxydifluoroalkylation of potentially bioactive drugs and natural products has also been carried out.
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http://dx.doi.org/10.1039/d0cc06980aDOI Listing
February 2021

Correction: Tang, L. et al., Effect of Oxygen Variation on High Cycle Fatigue Behavior of Ti-6Al-4V Titanium Alloy. 2020, , 3858.

Materials (Basel) 2020 Nov 26;13(23). Epub 2020 Nov 26.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, China.

The author wishes to make the following correction to this paper [...].
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http://dx.doi.org/10.3390/ma13235364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7731056PMC
November 2020

Cold Rolling Deformation Characteristic of a Biomedical Beta Type Ti-25Nb-3Zr-2Sn-3Mo Alloy Plate and Its Influence on α Precipitated Phases and Room Temperature Mechanical Properties During Aging Treatment.

Front Bioeng Biotechnol 2020 19;8:598529. Epub 2020 Oct 19.

Institute of Advanced Wear and Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, China.

The microstructure characteristics and texture evolution of a biomedical metastable beta Ti-25Nb-3Zr-2Sn-3Mo (TLM; wt%) titanium alloy plate cold rolled at various reductions were studied in this article. <110> texture was easily formed in the TLM alloy plates, and a large number of dislocation tangles were generated in the β matrix in the process of cold rolling deformation. The dislocation lines, dislocation cells, subgrain boundaries, and other crystal defects introduced during cold rolling had a great impact on the morphological characteristics and volume fraction of precipitated phases during aging. These typical crystal defects could be considered as the major triggers of the formation of second phases, and they could also shorten the time of β→α phase transformation. α precipitated phases, with a size range of 150-500 nm, were formed within the β matrix in the cold deformed 34% in conjunction with the aging specimen, resulting in the relatively high tensile strength of 931 MPa and the acceptable elongation of 6.9%. When the TLM alloy plate was cold rolled at a reduction of 60% in conjunction with aging, the maximum value of ultimate strength (1,005 MPa) was achieved, but the elongation value was relatively low owing to the formation of α precipitated phases with a large size around the subgrain boundaries. In this paper, the influence of crystal defects and subgrain boundaries on the morphology characteristics and volume fraction of α precipitated phases and mechanical properties will be discussed in detail.
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http://dx.doi.org/10.3389/fbioe.2020.598529DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7604361PMC
October 2020

[email protected] Hetero-structured Nanocomposites Are Highly Effective Photo-Catalysts for Organic Dye Degradation.

ACS Omega 2020 Oct 14;5(42):27463-27469. Epub 2020 Oct 14.

Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, No. 59 Qinglong Avenue, Fucheng District, Mianyang, Sichuan 621010, P. R. China.

[email protected] hetero-structured nanocomposites (HSNPs) were successfully synthesized via a hydrothermal approach. The morphology and crystal structure of these composites as well as their ability to act as photocatalysts for the degradation of methylene blue were investigated using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and UV-vis absorption spectroscopy. The developed [email protected] nanocomposites exhibited an 80% degradation rate with 30 min of visible light irradiation. To characterize the basis of the photocatalytic properties of these materials, the transient photocurrent densities were determined for the [email protected] HSNPs and pure dendritic CdS nanotrees. The results suggest that the photocatalytic activity may reflect electron transfer between the conduction band maximum of CdS and MoS. Additionally, the improved visible light absorption, decreased electron-hole pair recombination, and enhanced surface area for more effective dye absorption likely contribute to improved photocatalytic performance.
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http://dx.doi.org/10.1021/acsomega.0c03968DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7594156PMC
October 2020

Combined KOH/BEt Catalyst for Selective Deaminative Hydroboration of Aromatic Carboxamides for Construction of Luminophores.

Org Lett 2020 10 7;22(20):8086-8090. Epub 2020 Oct 7.

School of Pharmaceutical and Materials Engineering, Taizhou University, Jiaojiang 318000, P. R. China.

The selective catalytic C-N bond cleavage of amides into value-added amine products is a desirable but challenging transformation. Molecules containing iminodibenzyl motifs are prevalent in pharmaceutical molecules and functional materials. Here we established a combined KOH/BEt catalyst for deaminative hydroboration of acyl-iminodibenzyl derivatives, including nonheterocyclic carboxamides, to the corresponding amines. This novel transition-metal-free methodology was also applied to the construction of Clomipramine and luminophores.
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http://dx.doi.org/10.1021/acs.orglett.0c03033DOI Listing
October 2020

Knowledge-Based Descriptor for the Compositional Dependence of the Phase Transition in BaTiO-Based Ferroelectrics.

ACS Appl Mater Interfaces 2020 Oct 24;12(40):44970-44980. Epub 2020 Sep 24.

Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.

Descriptors play a central role in constructing composition-structure-property relationships to guide materials design. We propose a material descriptor, δτ, for the composition dependence of the Curie temperature () on single doping elements in BaTiO ferroelectrics, which is then generalized to a linear combination of multiple dopants in the solid solutions. The descriptor δτ depends linearly on the Curie temperature and also serves to separate the ferroelectric phase from the relaxor phase. We compare δτ to other commonly used descriptors such as the tolerance factor, electronegativity, and ionic displacement. By using regression analysis on our assembled experimental data, we show how it outperforms other descriptors. We use the trained machine-learned models to predict compositions in our search space with the largest ferroelectric, dielectric, and piezoelectric properties, namely, , electrostrain, and recoverable energy storage density. We experimentally verify our predictions for and classification into ferroelectrics and relaxors by synthesizing and characterizing six solid solutions in BaTiO ferroelectrics. Our definition of δτ can shed light on the design of knowledge-based descriptors in other systems such as Pb-based and Bi-based solid solutions.
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http://dx.doi.org/10.1021/acsami.0c12763DOI Listing
October 2020

Effect of Oxygen Variation on High Cycle Fatigue Behavior of Ti-6Al-4V Titanium Alloy.

Materials (Basel) 2020 Sep 1;13(17). Epub 2020 Sep 1.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China.

The element oxygen is expected to be a low-cost, strengthening element of titanium alloys due to its strong solid solution strengthening effect. High cycle fatigue behaviors of Ti-6Al-4V alloys with different oxygen contents (0.17%, 0.20%, 0.23% wt.%) were investigated in this paper. The results illustrated that Ti-6Al-4V-0.20O alloy possesses the highest fatigue strength and the lowest fatigue crack propagation rate. The fatigue fracture morphology verified that the fatigue cracks propagated transgranularly in both Ti-6Al-4V-0.17O and Ti-6Al-4V-0.20O alloys, and the fatigue cracks tended to extend intergranularly in the Ti-6Al-4V-0.23O alloy. The maximum nano-hardness varied from the <0001> direction to the <1¯21¯0> and <011¯0> directions with the increasing oxygen content, which suggested that the dominant slip system varied from prismatic slip to pyramidal slip. The number of the type dislocations increased with the oxygen content, which indicated that the number of the first-order pyramidal and the second-order pyramidal slip systems increased. The oxygen can significantly change the fatigue fracture mechanism of Ti-6Al-4V alloy: From transgranular fracture to intergranular fracture. These results are expected to provide valuable reference for the optimization of the composition and mechanical properties of titanium alloys.
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http://dx.doi.org/10.3390/ma13173858DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7503640PMC
September 2020

HFIP Promoted C3 Alkylation of Lawsone and 4-Hydroxycoumarin with Alcohols by Dehydrative Cross-Coupling.

J Org Chem 2020 08 6;85(16):10638-10647. Epub 2020 Aug 6.

Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China.

An environmentally benign system for the direct alkylation of lawsones and 4-hydroxycoumarins with alcohols in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) is reported. The reaction proceeded smoothly via a dehydrative cross-coupling process by utilizing the unique properties of HFIP. A variety of alkylated products and subsequent one-pot cyclized products (pyranonaphthoquinones and pyranocoumarins) could be obtained in 40-93% yields.
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http://dx.doi.org/10.1021/acs.joc.0c01207DOI Listing
August 2020

A mechanism for two-step thermal decomposition of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105).

Phys Chem Chem Phys 2020 Jun;22(24):13729-13736

Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), P. O. Box 919-311, Mianyang, 621900, P. R. China.

2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a representative of the new generation of low-sensitivity energetic materials and has been applied extensively in formulations as an insensitive high-energetic ingredient. Although the initial thermal decomposition mechanism of LLM-105 has been studied based on quantum chemical calculations, the internal mechanism of the two-step thermal decomposition still lacks experimental research. Thus, this study involves a detailed experimental study to reveal the mechanism of the two-step thermal decomposition of LLM-105. The results showed that LLM-105 decay was a consecutive reaction. The first-step reaction dominated the early stage of the LLM-105 decomposition, and its products participated in the reaction of the second step. The cleavage of NO2 and NH2 groups of LLM-105 mainly occurred in the first step, while gaseous products NO and C2N2 were released during the second reaction step. The first-step reaction had a higher oxygen consumption rate and a lower carbon consumption rate, producing more heat due to more extensive oxidation of the carbon backbone. The difference in the oxidative ability and reaction rate between the two steps resulted in a two-step exothermic and mass loss behavior. This study provides further insights into the entire reaction process of LLM-105 and would be helpful for its better application and for the design of new explosives.
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http://dx.doi.org/10.1039/d0cp02159hDOI Listing
June 2020

Microstructure and texture variations in high temperature titanium alloy Ti65 sheets with different rolling modes and heat treatments.

Materials (Basel) 2020 May 28;13(11). Epub 2020 May 28.

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China.

Ti65 alloy (Ti-5.8Al-4.0Sn-3.5Zr-0.5Mo-0.4Si-0.3Nb-1.0Ta-0.8W-0.05C) is the newly developed high temperature titanium alloy optimized from Ti60 alloys. The long-term service temperature of the alloy is as high as 650 °C, which is unattainable with the previous high temperature titanium alloy. It has excellent strength and excellent creep resistance, and has great application prospects in the aerospace industry. In the current study, the evolution of microstructure and texture of Ti65 alloy sheets developed by unidirectional rolling (UDR) and cross rolling (CR) followed by solution and aging treatment was investigated. The microstructure of the UDR sample consists of equiaxed , lamellar  and few elongated , and the texture is the combination of minor B-type and major T-type texture, with the main component of basal {0001} fiber texture and {0110}<2110>, respectively. Due to more active slip system resulted by transformed direction, the microstructure of the CR sample consists of more elongated , and the {0110}<0001> texture characterized as R-type texture forms in addition to B/T-type texture. With aging temperature increasing, the microstructures for both transform to duplex microstructure, and the thicknesses of lamellar  increase. B-type texture becomes stronger, while T/R-type texture are weakened, which is caused by the combination of recrystallization, spheroidization, and variant selection. An abnormal increasing of T/R-type texture but constant B-type texture happens in the CR-600 sample, which is related to high recrystallization fraction. It is expected that the research results can provide useful references for the rolling of high temperature titanium alloy sheets and the precise control of microstructure/texture.
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http://dx.doi.org/10.3390/ma13112466DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7321286PMC
May 2020

Bio-inspired attitude measurement method using a polarization skylight and a gravitational field.

Appl Opt 2020 Mar;59(9):2955-2962

High precision and reliability attitude measurement play an important role in autonomous unmanned navigation. Finding inspiration from desert ants, known as highly efficient navigators who can find their way after foraging for hundreds of meters from their home in hostile environments, we propose an attitude measurement method using polarization skylight and gravitational field. Contrary to the previous method, we utilize three-dimensional polarization vectors and any one-dimensional output of the accelerometers to calculate attitudes. In addition, we designed an accelerometer component selection algorithm, which is to select the one-dimensional component with the minimum motion acceleration from the output of the three-dimensional accelerometer. With this method, even if the carriers remain in a maneuvering state, the motion acceleration of the vehicle will have less impact on the accuracy of attitude measurement. To evaluate the performance of our method, the outdoor experiment was carried out to compare our method with existing traditional methods. Comparison results show that our method has higher measurement accuracy than others and is still applicable in the case of carriers maneuvering in practice under a clear sky.
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http://dx.doi.org/10.1364/AO.387770DOI Listing
March 2020

[3,3]-Sigmatropic Rearrangement/Haller-Bauer Reaction of Aryl Sulfoxides and Selenoxides with Difluoroenoxysilanes: Access to CFH-Containing Chalcogenides.

Org Lett 2020 02 16;22(3):1164-1168. Epub 2020 Jan 16.

Advanced Research Institute and Department of Chemistry , Taizhou University , 1139 Shifu Avenue , Taizhou 318000 , P. R. China.

A mild and general procedure for the difluoromethylation of organochalcogen compounds has been accomplished via sulfoxide and selenoxide-directed [3,3]-sigmatropic rearrangement/Haller-Bauer reaction with difluoroenoxysilanes. The reactions showed good functional group compatibility, wide substrate applicability, and facile scalability. The synthetic utility is highlighted by the iterative use of this protocol to construct multi-CFH-containing chalcogenides and the late-stage modification of pharmaceuticals.
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http://dx.doi.org/10.1021/acs.orglett.0c00018DOI Listing
February 2020

Phellinus linteus polysaccharide extract improves insulin resistance by regulating gut microbiota composition.

FASEB J 2020 01 28;34(1):1065-1078. Epub 2019 Nov 28.

State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, P.R. China.

The hypoglycemic effect of Phellinus linteus polysaccharide extract (PLPE) has been documented in several previous studies, but the functional interactions among PLPE, gut microbiota, and the hypoglycemic effect remain unclear. We examined the regulatory effect of PLPE on gut microbiota, and the molecular mechanism underlying improvement of insulin resistance, using a type 2 diabetic rat model. Here, 24 male Sprague-Dawley rats were randomly divided into four groups that were subjected to intervention of saline (normal and model control group), metformin (120 mg/kg.bw), and PLPE (600 mg/kg.bw) by oral administration. After 8 weeks of treatment, PLPE increased levels of short-chain fatty acids (SCFAs) by enhancing abundance of SCFA-producing bacteria. SCFAs maintained intestinal barrier function and reduced lipopolysaccharides content in blood, thereby helping to reduce systemic inflammation and reverse insulin resistance. Our findings suggest that PLPE (in which polysaccharides are the major component) has potential application as a prebiotic for regulating gut microbiota composition in diabetic patients.
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http://dx.doi.org/10.1096/fj.201901943RRDOI Listing
January 2020

Formation experiment with heading angle reference using sky polarization pattern at twilight.

Appl Opt 2019 Dec;58(34):9331-9337

Consistency has always been an important topic in formation cooperation research. Traditional navigation methods, such as inertial navigation and geomagnetic navigation, have the disadvantages of error accumulation and low stability, thus reducing the consistency of formation. We propose to use the skylight polarization pattern to provide heading angle reference for formation cooperation of multi-agents. The experimental results show that the polarization navigation has good stability and no error accumulation. First, we analyzed the consistency of using the skylight polarization pattern to provide a heading reference for formation experiments. Then, based on the bionic polarization navigation sensor, we measured the difference of the skylight polarization azimuth of different observers at twilight. Further, a mobile robot platform was built with its heading angle provided by a polarization navigation sensor. Finally, we present an overview of a 3-robots platform formation experiment at twilight.
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http://dx.doi.org/10.1364/AO.58.009331DOI Listing
December 2019

First-Principles-Based Force Field for 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105).

ACS Omega 2019 Dec 4;4(25):21054-21062. Epub 2019 Dec 4.

Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.

2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a highly promising energetic material (EM) with high safety. Understanding its microscopic response mechanisms within the external stimulus is meaningful for the design of EMs. In order to comprehend the complicated phenomena, it is necessary to employ molecular simulation methods to investigate the response mechanisms with the force field (FF) at an atomic level. In this work, we developed a tailored FF for LLM-105 based on first-principles calculations. The validity of the FF was evaluated by molecular dynamics simulations. The structural parameters of LLM-105 predicted by FF are in good agreement with the experimental values, such as lattice constant, bond length, bond angle, dihedral angle and center of mass, and so forth. Moreover, the FF possesses good performance to describe the structural response on pressure accurately. In general, our work not only builds a balanced FF in gas and condensed phases, but also provides a useful tool to study the properties about LLM-105 at a large scale, which is helpful to improve the understanding about the balance between energy and safety in EMs.
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http://dx.doi.org/10.1021/acsomega.9b02410DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6921264PMC
December 2019

Autodegradable clusters made from superparamagnetic nanoparticles with drug-release properties.

Nanomedicine (Lond) 2019 11 17;14(22):2897-2908. Epub 2019 Sep 17.

Institute of Chemical Materials China Academy of Engineering Physics (CAEP), Mianyang, 621900, PR China.

The agglomeration of nanoparticles plays an important role in the preparation of nanostructured materials, which has implications in their practical applications such as plasma nanosensor and drug release. Highly stable individual superparamagnetic -FeO nanoparticles with diameter of 5 nm were first synthesized in water. These particles were then assembled into spherical clusters with diameters of approximately 200 nm using a simple and versatile method. The prepared -FeO nanoparticle-based clusters were then used for aminophylline drug loading and release properties investigation. The results show the high drug load rate, release speed and release rate. The present materials and method present great potential in drug-release application.
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http://dx.doi.org/10.2217/nnm-2019-0278DOI Listing
November 2019
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