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1.
J Am Chem Soc ; 146(10): 6471-6475, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38428039

RESUMEN

Adaptive materials that exhibit a multichromatic response as a function of applied stimulus are highly desirable, as they can result in applications ranging from smart surfaces to anticounterfeit devices. Here we report on such a system based on an intriguing thermal 1,2-BF2 shift that transforms a visible-light-activated azo-BF2 photoswitch into a BF2-hydrazone fluorophore (BODIHY) in both solution and the solid-state. Structure-property analysis, in conjunction with DFT calculations, reveals that the shift is catalyzed by the spatial proximity of an oxygen atom next to the BF2 group and that the activation originates from an electronic and not steric effect. Theoretical calculations also show that while the energy barrier for the trans → BODIHY transformation is accessible at room temperature (thermal half-life of 30 h), the cis → BODIHY transformation has a much higher barrier, which is why the 1,2-BF2 shift is not observed for the cis form. The photoswitching of the azo-BF2, in conjunction with the 1,2-BF2 shift, was then used in the multicolor modulation of a switch-containing cross-linked polydimethylsiloxane film using light and/or heat stimuli, elaborating the usefulness of the sophisticated reaction cascade that can be accessed from this simple system.

2.
J Org Chem ; 89(1): 681-686, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38065576

RESUMEN

Herein, we report the introduction of a silole unit into cycloparaphenylenes (CPPs), and two compounds [12]Si3CPP and [16]Si4CPP are obtained by a platinum- and gold-mediated cyclooligomerization strategy. Their optical and electronic properties are studied by UV-vis absorption and fluorescence spectra, which show red shifts and higher photoluminescence quantum yields (PLQYs) compared with the corresponding CPPs.

3.
Angew Chem Int Ed Engl ; 63(44): e202406273, 2024 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-39076060

RESUMEN

The chlorine evolution reaction (CER) is a crucial anode reaction in the chlor-alkali industrial process. Precious metal-based dimensionally stable anodes (DSA) are commonly used as catalysts for CER but are constrained by their high cost and low selectivity. Herein, a Pt dual singe-atom catalyst (DSAC) dispersed on fluorine-doped carbon nanotubes (F-CNTs) is designed for an efficient and robust CER process. The prepared Pt DSAC demonstrates excellent CER activity with a low overpotential of 21 mV to achieve a current density of 10 mA cm-2 and a remarkable mass activity of 3802.6 A gpt -1 at an overpotential around 30 mV, outperforming those of commercial DSA and Pt single-atom catalyst. The excellent CER performance of Pt DSAC is attributed to the high atomic utilization and improved intrinsic activity. Notably, introducing fluorine atoms on CNTs increases the oxidation and chlorination resistance of Pt DSAC, and reduces the demetalization ratio of Pt atoms, resulting in excellent long-term CER stability. Theoretical calculations reveal that several Pt DSAC configurations with optimized first-shell ligands and interatomic distance display lower energy barriers for Cl intermediates generation and weaker ionic Pt-Cl bond interaction, which are favorable for the CER process.

4.
Mol Cell Probes ; 69: 101913, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37068562

RESUMEN

LINC00511 is an long non-coding RNA (lncRNA) of ncRNAs,This study aimed to investigate whether the lncRNA LINC00511 could encode a small peptide, LINC00511-133aa, and whether this peptide could promote breast cancer cell metastasis and stemness by activating the wnt/ß-catenin pathway. The LINC00511-133aa coding sequence vector and control vector were transfected into MCF-7 and MDA-MB-231 breast cancer cells, with subsequent assessment of peptide expression using PCR, western blotting, and immunofluorescence assays. Cell proliferation, invasion, and apoptosis were evaluated using CCK8, apoptotic, wound healing, and transwell invasion assays, while the characteristic changes of tumor stem cells were detected through sphere-forming assay and western blot analyses of the stemness markers Oct4, Nanog, and SOX2. Results showed that LINC00511-133aa was indeed encoded by LINC00511 and promoted the invasiveness and stemness of breast cancer cells while limiting apoptosis by modulating the expression levels of wnt/ß-catenin pathway-related proteins Bax, c-myc, and CyclinD1, as well as facilitating ß-catenin protein entry into the nucleus. This study provides evidence for the potential involvement of lncRNA LINC00511 and its peptide product in breast cancer progression via the regulation of the wnt/ß-catenin pathway.


Asunto(s)
Neoplasias de la Mama , ARN Largo no Codificante , Humanos , Femenino , beta Catenina/genética , beta Catenina/metabolismo , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , ARN Largo no Codificante/genética , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Péptidos/genética , Péptidos/metabolismo , Invasividad Neoplásica/genética
5.
Inorg Chem ; 62(8): 3518-3524, 2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36795939

RESUMEN

The activation of tetrafluoromethane (CF4) is quite challenging. The current methods have a high decomposition rate but are expensive, and therefore, their widespread use is limited. Here, inspired by the successful C-F activation within saturated fluorocarbons, we have designed a rational approach based on two-coordinate borinium for activating CF4 using density functional theory (DFT) calculations. Our calculations predict that this approach is both thermodynamically and kinetically favorable.

6.
Phys Chem Chem Phys ; 25(15): 10599-10603, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-36994919

RESUMEN

Methylation is one of the crucial steps for drug discovery, organic synthesis, and catalysis. Despite being a versatile and well-known chemical reaction, its chemoselectivity has not been well addressed. In this paper, we reported a thorough experimental and computational investigation of the selective N-methylation of N-heterocyclic compounds, mainly quinolines and pyridines. These reactions were conducted in a base-free manner under ambient conditions using iodomethane as the methylating reagent, exhibited good chemoselectivity, and were tolerant of other amine, carboxyl, or hydroxyl functional groups without needing protection. To this end, 13 compounds were synthesized as a proof-of-concept and 7 crystal structures were obtained. However, the chemoselectivity failed in the presence of a thiol group. Detailed quantum chemical calculations provided insights into the N-methylation mechanism and its selectivity and demonstrated that the isomerization induced by ground-state intramolecular proton transfer (GSIPT) in the presence of a thiol group inhibits the N-methylation.

7.
BMC Genomics ; 23(1): 706, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36253723

RESUMEN

BACKGROUND: Livestock animals is of great significance in agricultural production. However, the role of specific gene expression, especially alternative splicing in determining phenotype, is not well understood. The livestock research community needs a gene expression and alternative splicing database contributing to livestock genetic improvement. DESCRIPTION: We report the construction of LivestockExp ( https://bioinfo.njau.edu.cn/livestockExp ), a web-based database server for the exploration of gene expression and alternative splicing using 43,710 uniformly processed RNA-seq samples from livestock animals and several relative species across six orders. The database is equipped with basic querying functions and multiple online analysis modules including differential/specific expression analysis, co-expression network analysis, and cross-species gene expression conservation analysis. In addition to the re-analysis of public datasets, users can upload personal datasets to perform co-analysis with public datasets. The database also offers a wide range of visualization tools and diverse links to external databases enabling users to efficiently explore the results and to gain additional insights. CONCLUSION: LivestockExp covers by far the largest number of livestock animal species and RNA-seq samples and provides a valuable data resource and analysis platform for the convenient utilization of public RNA-seq datasets.


Asunto(s)
Empalme Alternativo , Ganado , Animales , Bases de Datos Genéticas , Expresión Génica , Internet , Ganado/genética , RNA-Seq
8.
J Org Chem ; 86(18): 12591-12596, 2021 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-34469157

RESUMEN

A practicable strategy to a reversible mechanochromic material featuring interconversion of classical/frustrated Brönsted pairs has been established. We report the mechanochromic property of 2,6-bis(4-biphenyl)isonicotinic acid (1), which features a frustrated Brönsted pair in the crystalline form and a classical Brönsted pair after grinding. A large mechanochromic shift was found from 428 to 505 nm. In addition, compound 1 also exhibits acidochromic behavior, which further proves that the formation of an acid-base interaction is responsible for the mechanochromic phenomenon.

9.
Chemistry ; 26(71): 17222-17229, 2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33006821

RESUMEN

A series of two-coordinate AuI and CuI complexes (3 a, 3 b and 5 a, 5 b) are reported as new organometallic thermally activated delayed fluorescence (TADF) emitters, which are based on the carbene-metal-carbazole model with a pyridine-fused 1,2,3-triazolylidene (PyTz) ligand. PyTz features low steric hindrance and a low-energy LUMO (LUMO=-1.47 eV) located over the π* orbitals of the whole ligand, which facilitates intermolecular charge transfer between a donor (carbazole) and an accepter (PyTz). These compounds exhibit efficient TADF with microsecond lifetimes. Temperature-dependent photoluminescence kinetics of 3 a supports a rather small energy gap between S1 and T1 (ΔE S 1 - T 1 =60 meV). Further experiments reveal that there are dual-emission properties from a monomer-dimer equilibrium in solution, exhibiting single-component multicolor emission from blue to orange, including white-light emission.

10.
J Org Chem ; 85(19): 12036-12043, 2020 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-32902273

RESUMEN

Mesoionic N-heterocyclic olefins have been developed, which feature high ylidic character. These compounds have been used as efficient catalysts for hydroboration of imines, nitriles, and N-heteroarenes.

11.
J Org Chem ; 85(11): 6951-6958, 2020 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-32408749

RESUMEN

Five m-phenylene-embedded cycloparaphenylenes m3[9]CPP 1-5 were synthesized by the platinum-mediated cyclooligomerization strategy with high overall yields. The structures of m3[9]CPP 1-3 were determined by X-ray diffraction analysis. Compared to [9]CPP, m3[9]CPP 1 caused a significant blueshift in the UV-vis absorption and fluorescence spectra. This result shows that the radial π-conjugation is distorted and partially interrupted. The photophysical properties of m3[9]CPP 1 were further tuned by the introduction of various substituents for m3[9]CPP 2-5. Methoxy group substitution at m-phenylene did not change the photophysical properties significantly. Replacement of m-phenylene by tetrafluoro-m-phenylene achieved a significant blueshift. When the carboxyl group was embedded at m-phenylene or the methoxy group was embedded at p-phenylene, significant redshifts were observed with blue color emission. Theoretical calculations revealed that the decrease in the HOMO-LUMO gap in m3[9]CPP 4 and 5 is favorable for the redshift of the fluorescence spectrum.

12.
J Manipulative Physiol Ther ; 43(5): 446-456, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32829947

RESUMEN

OBJECTIVE: To compare the biomechanical effect of lumbar fixed-point oblique pulling manipulation and traditional oblique pulling manipulation in the treatment of protrusion of lumbar intervertebral disk, and investigate the influence of disk degeneration on the 2 manipulations. METHODS: Three finite element models including 1 normal model, 1 mild degeneration, and 1 moderate degeneration model of L3-S1 were developed to simulate 2 oblique pulling manipulations. The disk protrusion was assumed to be in the left central and subarticular zone of the L4-L5 disk, and manipulations were carried out on the right. A 15-Nm right axial rotation moment and 150-N compressive loading were imposed on the upper endplate of L3 to simulate a traditional oblique pulling manipulation. To simulate lumbar fixed-point oblique pulling manipulation, in addition to a 15-Nm moment and 150-N compressive loading imposed on the L3 upper endplate, a 50-N force was imposed on the right lateral area of the L4 spinous process in a left front direction. The displacement and stress in the left central and subarticular zone of the L4-L5 disk were calculated and compared in the 3 models. RESULTS: The average displacement and stress in the left central and subarticular zone of L4-L5 disk were higher in fixed-point oblique pulling manipulation than those in traditional oblique pulling manipulation (P < .05). In addition, the values of average stress and displacement decreased significantly with the increase of lumbar disk degeneration (P < .05). CONCLUSION: Lumbar fixed-point oblique pulling manipulation showed a better biomechanical effect than traditional oblique pulling manipulation, and lumbar disk degeneration affected the 2 manipulations adversely in the virtual treatment of protrusion of the lumbar intervertebral disk using finite element models.


Asunto(s)
Degeneración del Disco Intervertebral/terapia , Desplazamiento del Disco Intervertebral/terapia , Vértebras Lumbares/fisiopatología , Región Lumbosacra/fisiopatología , Fenómenos Biomecánicos/fisiología , Análisis de Elementos Finitos , Humanos , Disco Intervertebral
13.
Beilstein J Org Chem ; 16: 78-87, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32082427

RESUMEN

The synthesis of 4,5-diiodo-1,3-dimesityl-1,2,3-triazolium salts with different anions have been developed. These triazolium salts show diverse aggregation via halogen bonding between C-I bonds and anions. Triazolium with halide anions exists as a tetramer with saddle conformation. Triazolium tetrafluoroborate exists as a trimer with Chinese lantern shape conformation. Triazolium trifluoroacetate and acetate exist as dimers, respectively, while the former shows boat conformation and the latter forms rectangle conformation. Triazolium salts form a linear polymer with polyiodide.

14.
Cytokine ; 118: 124-129, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-29656959

RESUMEN

Interleukin (IL)-33/ST2 pathway plays a pivotal role in tumorigenesis through influencing cancer stemness, tumor growth, metastasis, angiogenesis, and accumulation of regulatory T cells in tumor microenvironments. The aim of this study was to investigate the association of IL-33 rs7025417 and ST2 rs3821204 with the risk of hepatocellular carcinoma (HCC). Genotyping of IL-33 rs7025417 and ST2 rs3821204 was carried out using a Taqman assay. IL-33 and ST2 mRNA was examined using real-time PCR and plasma IL-33 and sST2 levels were measured using enzyme-linked immunosorbent assay. The ST2 rs3821204 CC genotype was associated with a significantly increased risk of HCC (CC vs. GG: adjusted OR = 2.29, 95% CI, 1.39-3.78; dominant model: adjusted OR = 1.58, 95% CI, 1.12-2.23; recessive model: adjusted OR = 1.88, 95% CI, 1.21-2.93; C vs. G: adjusted OR = 1.53, 95% CI, 1.20-1.95). Gene-environment interaction analysis showed that the risk effect of rs3821204 CG/CC genotypes was more evident in smokers (adjusted OR = 1.70, 95% CI, 1.13-2.55) and drinkers (adjusted OR = 1.57, 95% CI, 1.04-2.37). The increased risk was also observed in combined analysis. Moreover, HCC patients with ST2 rs3821204 CC genotype had higher levels of mRNA and protein expression (P < 0.05). These findings suggest that ST2 rs3821204 CC genotype may contribute to hepatocarcinogenesis by enhancing ST2 production at the transcriptional and translational level.


Asunto(s)
Pueblo Asiatico/genética , Carcinoma Hepatocelular/genética , Predisposición Genética a la Enfermedad/genética , Proteína 1 Similar al Receptor de Interleucina-1/genética , Interleucina-33/genética , Neoplasias Hepáticas/genética , Polimorfismo de Nucleótido Simple/genética , Alelos , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes/genética , Estudios de Asociación Genética/métodos , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Transducción de Señal/genética , Microambiente Tumoral/genética
15.
J Org Chem ; 84(9): 5230-5235, 2019 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-30920219

RESUMEN

[ n]Cyclo-4,4'-biphenylene-2″,5″-thienylenes ([ n]CP2T, n = 3, 4), [ n]cyclo-4,4'-biphenyl-ene-2″,5″-selenylenes ([ n]CP2S, n = 3, 4), and [ n]cyclo-4,4'-biphenylene-2″,5″-ethylenedioxythienylenes ([ n]CP2E, n = 3) were synthesized in few steps with high overall yields. These nanorings were prepared through platinum-mediated cyclooligomerization of 2,5-bis(4-pinacolboryl-phenyl)chalcophenes. The X-ray crystallographic analysis of [4]CP2S showed that it employed a cone-shaped conformation in the solid state. Furthermore, their photophysical properties were investigated by using the UV-vis absorption spectra and fluorescence spectra. In particular, selenophene and 3,4-ethylenedioxythiophene-embedded cycloparaphenylenes, which showed significant red shifts in the UV-vis absorption and fluorescence spectra compared with thiophene analogues, are reported here for the first time.

16.
Tumour Biol ; 37(5): 6403-11, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26631037

RESUMEN

Cancer remains as the leading cause of death all over the world due to the lack of efficient diagnostic techniques and therapeutic methods. Many studies have reported the potential diagnostic value of microRNA-17 (miRNA-17, miR-17) family members as biomarkers for cancer detection. However, inconsistent results were revealed from a wide range of studies. As a result of this, a meta-analysis based on 19 studies was conducted to assess the diagnostic performance of miR-17 family for cancer detection. A total of 1772 patients with certain types of cancer and 1320 healthy controls were involved in these studies. The overall diagnostic accuracy was measured by the following: sensitivity, 0.67 (95 % confidence interval (CI) 0.60-0.74); specificity, 0.83 (95 % CI 0.74-0.85); positive likelihood ratio (PLR), 3.9 (95 % CI 2.6-5.9); negative likelihood ratio (NLR), 0.40 (95 % CI 0.34-0.48); and diagnostic odds ratio (DOR), 10 (95 % CI 6-16), respectively. Additionally, the pooled area under the summary receiver operator characteristic (SROC) curve (area under the curve (AUC)) was 0.79 (95 % CI 0.75-0.82), indicating a relatively low accuracy of miR-17 family as biomarkers for cancer detection. Subgroup analysis further showed that miR-17 family had more reliable performance in cancer diagnosis for Asian than that for Caucasian. Moreover, multiple miRNAs containing miR-17, -20a/b, and -93 reflected higher diagnostic accuracy than both miR-106a/b (single miRNA) and the overall miR-17 family assay. Therefore, appropriate combinations of miR-17 family may be used as non-invasive screening biomarkers for cancer, and it is necessary to carry out a large-scale population-based study to further assess the potential diagnostic value of miR-17 family.


Asunto(s)
Biomarcadores de Tumor , MicroARNs/genética , Familia de Multigenes , Neoplasias/diagnóstico , Neoplasias/genética , Estudios de Casos y Controles , Humanos , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Micromachines (Basel) ; 15(9)2024 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-39337827

RESUMEN

This study developed a new metallography-property relationship neural network (MPR-Net) to predict the relationship between the microstructure and mechanical properties of 316L stainless steel built by laser powder bed fusion (LPBF). The accuracy R2 of MPR-Net was 0.96 and 0.91 for tensile strength and Vickers hardness predictions, respectively, based on optical metallurgy images. Feature visualisation methods, such as gradient-weighted class activation mapping (Grad-CAM) and clustering, were employed to interpret the abstract features within the MPR-Net, providing insights into the molten pool morphology and grain formation mechanisms during the LPBF process. Experimental results showed that the optimal process parameters-190 W laser power and 700 mm/s scanning speed-yielded a maximum tensile strength of 762.83 MPa and a Vickers hardness of 253.07 HV0.2 with nearly full densification (99.97%). The study marks the first application of a convolutional neural network (MPR-Net) to predict the mechanical properties of 316L stainless steel samples manufactured through laser powder bed fusion (LPBF) based on metallography. It innovatively employs techniques such as gradient-weighted class activation mapping (Grad-CAM), spatial coherence testing, and clustering to provide deeper insights into the workings of the machine learning model, enhancing the interpretability of complex neural network decisions in material science.

18.
Org Lett ; 26(29): 6092-6097, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-38990286

RESUMEN

ß-Amino nitriles are important molecular scaffolds. Cyanoalkylation of imines is the most straightforward method for the construction of these scaffolds. In this study, we report the novel cyanoalkylation of imines via radical coupling enabled by a photoactive electron donor-acceptor complex. This strategy is characterized by mild conditions, broad reaction scopes, and high atom economy. The scalability and practicality of this strategy are demonstrated by a 40 g continuous flow system from which a variety of important pharmaceutical-related molecules were obtained.

19.
Int J Biol Macromol ; 260(Pt 2): 129526, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38242387

RESUMEN

A model system of gelatinized wheat starch (GWS) and lauric acid (LA) was used to examine the effect of residual short-range molecular order in GWS on the formation of starch-lipid complexes. The extent of residual short-range molecular order, as determined by Raman spectroscopy, decreased with increasing water content or heating duration of gelatinization. The enthalpy changes, crystallinity, short-range molecular order and the in vitro enzymic digestion of GWS-LA complexes increased initially to a maximum and then declined as the short-range molecular order in GWS decreased, showing that there was an optimal amount of residual short-range molecular order in GWS for maximizing GWS-LA complexes formation. Below this optimum amount, the limited disruption of short-range molecular order may constrain the mobility of amylose chains for complexation with LA, whereas with excessive disruption above this amount the amylose chains may be too disorganized or entangled to form complexes with LA. The susceptibility of GWS-LA complexes to enzymatic hydrolysis was influenced by both long- and short-range structural order, and to a lesser extent the amounts of complexes. This study showed clearly the role of short-range molecular order in gelatinized starch in influencing the formation of GWS-LA complexes.


Asunto(s)
Amilosa , Almidón , Almidón/química , Amilosa/química , Ácidos Láuricos/química , Hidrólisis
20.
Adv Mater ; 36(41): e2407974, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39152929

RESUMEN

Dual-atom catalysts (DACs) with atomically dispersed dual-sites, as an extension of single-atom catalysts (SACs), have recently become a new hot topic in heterogeneous catalysis due to their maximized atom efficiency and dual-site diverse synergy, because the synergistic diversity of dual-sites achieved by asymmetric microenvironment tailoring can efficiently boost the catalytic activity by optimizing the electronic structure of DACs. Here, this work first summarizes the frequently-used experimental synthesis and characterization methods of DACs. Then, four synergistic catalytic mechanisms (cascade mechanism, assistance mechanism, co-adsorption mechanism and bifunction mechanism) and four key modulating methods (active site asymmetric strategy, transverse/axial-modification engineering, distance engineering and strain engineering) are elaborated comprehensively. The emphasis is placed on the effects of asymmetric microenvironment of DACs on oxygen/carbon dioxide reduction reaction. Finally, some perspectives and outlooks are also addressed. In short, the review summarizes a useful asymmetric microenvironment tailoring strategy to speed up synthesis of high-performance electrocatalysts for different reactions.

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