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1.
Int J Biol Macromol ; 256(Pt 2): 128233, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38040166

RESUMO

In this work, we report an environmentally friendly renewable nanocomposite magnetic lignin-based palladium nanoparticles (Fe3O4-lignin@Pd-NPs) for efficient wastewater treatment by decorating palladium nanoparticles without using any toxic reducing agents on the magnetic lignin abstracted from Poplar. The structure of composite Fe3O4-lignin@Pd-NPs was unambiguously confirmed by XRD, SEM, TEM, EDS, FTIR, and Zeta potential. After systematic evaluation of the use and efficiency of the composite to remove toxic organic dyes in wastewater, some promising results were observed as follows: Fe3O4-lignin@Pd-NPs exhibits highly active and efficient performance in the removal of toxic methylene blue (MB) (up to 99.8 %) wastewater in 2 min at different concentrations of MB and different pH values. Moreover, except for toxic MB, the other organic dyes including Rhodamine B (RhB), Rhodamine 6G (Rh6G), and Methyl Orange (MO) can also be removed efficiently by the composite. Finally, the easily recovered composite Fe3O4-lignin@Pd-NPs exhibits well stability and reusability, and catalytic efficiency is maintained well after ten cycles. In conclusion, the lignin-based magnetism Pd composite exhibits powerful potential practical application in industrial wastewater treatment.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Purificação da Água , Lignina , Nanopartículas Metálicas/química , Paládio/química , Águas Residuárias , Corantes
2.
J Stomatol Oral Maxillofac Surg ; 125(1): 101630, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37689138

RESUMO

INTRODUCTION: The aim of this study was to evaluate the outcome of skeletal Class II and anterior open bite patients who received simultaneous Le fort I osteotomies with temporomandibular joint (TMJ) prostheses or bimaxillary orthognathic surgery. MATERIALS AND METHODS: Patients with condylar resorption (CR) were treated by TMJ prostheses and orthognathic surgery and divided into two groups. Cephalometric radiographs were obtained before and after operation to find out the surgical alteration by comparing measures at different time points. RESULTS: 23 patients were included. Mean overbite of the patients was increased by 3.39 mm in TMJ prostheses group and 3.24 mm in orthognathic group. Occlusal plane angle was averagely rotated -6.06° and 1.31°; mandibular plane counterclockwise rotated 12.23° and 5.81°, respectively. The increase of ramus height in TMJ prostheses group were significantly greater than orthognathic surgery group (8.02 ± 1.96 mm vs. -0.09 ± 1.29 mm). The overall treatment effect was stable in both groups during the 1-year follow up. DISCUSSION: Two surgical plans seem to be reliable treatments of anterior open bite and mandibular retrognathism caused by temporomandibular disease. TMJ prostheses with simultaneous Le fort I osteotomies close open bite by lengthening the height of ramus and rotating maxillo-mandibular complex counterclockwise, while bimaxillary orthognathic surgery by rotating maxilla clockwise and mandible counterclockwise without rebuilding ramus.


Assuntos
Prótese Articular , Mordida Aberta , Cirurgia Ortognática , Humanos , Mordida Aberta/diagnóstico , Mordida Aberta/cirurgia , Estudos Retrospectivos , Articulação Temporomandibular/cirurgia
3.
Inorg Chem ; 62(46): 18820-18824, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37935044

RESUMO

We present the synthesis, structural characterization, and reactivity of alkylideneborane 2, supported by π-donating N-heterocyclic imino and σ-donating N-heterocyclic carbene (NHC) ligands. The incorporation of these ligands effectively weakens the B═C bond strength, leading to enhanced reactivity. Consequently, selective cleavage of the B═C bond can be achieved using pyridine-N-oxide, sulfur, and selenium, resulting in the formation of 1,3-dioxa-2,4-diboretane 3, thioxoborane 4, and selenoborane 5, respectively. Furthermore, intriguing B═C bond insertions with CO2 and CS2 are observed, affording zwitterionic borenium/fluorenide 6 and dithiaboretane 7. The former species 6 is readily converted to transient oxoborane and imidazolium enolate, showcasing the bora-Wittig reaction of alkylideneborane. This investigation highlights the potential of alkylideneborane as a versatile building block for synthesizing novel organoboron compounds through unconventional transformations.

4.
ACS Appl Mater Interfaces ; 15(37): 44493-44502, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37675462

RESUMO

The demand for scintillators with ultrafast decay times, high spatial resolutions, and high stabilities is increasing due to the development of ultrafast hard X-ray detection, hard X-ray imaging, and high-energy physics facilities. γ-CuI single crystals, which exhibit ultrafast luminescence and high stopping power for hard X-rays, hold great promise for such applications. However, slow luminescence and poor stability caused by surface iodine deficiencies hinder the practical use of γ-CuI. Herein, we treated a γ-CuI single crystal by iodine annealing and SiO2 coating and investigated its crystal structure and luminescence properties in detail. Iodine annealing significantly enhanced the near-band-edge emission of the γ-CuI crystal with an ultrafast decay time of less than 1 ns, while completely suppressing the slow luminescence. Moreover, the SiO2 film effectively prevented the oxidation and decomposition of surface iodine, leading to substantial improvement in luminescence stability. The γ-CuI crystal demonstrated an ultrahigh spatial resolution of 1.5 µm in X-ray imaging, highlighting its potential for ultrafast hard X-ray imaging applications. This study provides insight into the growth, optimization, and application of γ-CuI crystals, advancing the field of scintillator materials.

5.
Cartilage ; : 19476035231200359, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37750508

RESUMO

OBJECTIVE: This study aimed to isolate and compare the mesenchymal stem cell characteristics of CD90+ cells from different fibrocartilage tissues in the temporomandibular joint (TMJ), the knee joint, and the intervertebral joint to further understand the similarities and differences of these 4 fibrocartilage tissues. METHODS: CD90+ cells were isolated from TMJ disc, condylar cartilage, meniscus, and intervertebral disc by using magnetic-activated cell sorting. Cellular assays including 4.5-ethynyl-2'-deoxyuridine labeling, multilineage differentiation, colony formation, and cell migration were conducted to compare their mesenchymal stem cell characteristics. Immunofluorescent staining was performed for observing the expression of actively proliferating CD90+ cells within the tissues. H&E staining and Safranine O staining were used to compare the histological features. RESULTS: The CD90+ cells derived from these 4 fibrocartilage tissues exhibited comparable cell proliferation abilities. However, the cells from the TMJ disc displayed limited multilineage differentiation potential, colony formation, and cell migration abilities in comparison with the cells from the other fibrocartilage tissues. In vivo, there was relatively more abundant expression of CD90+ cells in the TMJ disc during the early postnatal stage. The limited EDU+ cell numbers signified a low proliferation capacity of CD90+ cells in the TMJ disc. In addition, we observed a significant decrease in cell density and a restriction in the synthesis of extracellular proteoglycans in the TMJ disc. CONCLUSION: Our study highlights the spatial heterogeneity of CD90+ cells in the fibrocartilages of different joint tissues, which may contribute to the limited cartilage repair capacity in the TMJ disc.

6.
Int J Oral Sci ; 15(1): 36, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626033

RESUMO

The anterior disc displacement (ADD) leads to temporomandibular joint osteoarthritis (TMJOA) and mandibular growth retardation in adolescents. To investigate the potential functional role of fibrocartilage stem cells (FCSCs) during the process, a surgical ADD-TMJOA mouse model was established. From 1 week after model generation, ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis (OA)-like joint cartilage degeneration, manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis. Lineage tracing using Gli1-CreER+; Tmfl/-mice and Sox9-CreER+;Tmfl/-mice showed that ADD interfered with the chondrogenic capacity of Gli1+ FCSCs as well as osteogenic differentiation of Sox9+ lineage, mainly in the middle zone of TMJ cartilage. Then, a surgically induced disc reposition (DR) mouse model was generated. The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice. And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment. In conclusion, ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage, resulting in cartilage degeneration and loss of subchondral bone homeostasis, finally causing TMJ growth retardation. DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.


Assuntos
Osteoartrite , Osteogênese , Animais , Camundongos , Proteína GLI1 em Dedos de Zinco , Fibrocartilagem , Articulação Temporomandibular , Modelos Animais de Doenças , Células-Tronco , Transtornos do Crescimento
7.
J Am Chem Soc ; 145(34): 18767-18772, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37582249

RESUMO

Exploration of the metallomimetic chemistry of main group elements is of the utmost importance from the perspective of both fundamental research and potential applications. Here, we report the synthesis, bonding analysis, and reactivities of an isolable diiminoborane, Mes*B≡N─N≡BMes* (Mes* = 2,4,6-tri-tert-butylphenyl) (1), a BN analogue of butadiyne. This species is characterized by a conjugated B≡N─N≡B moiety, a structural feature that enables the controlled release of N2 when it is exposed to organic nitriles. Furthermore, the N2 unit in 1 could be reduced to an ammonium salt via cleavage of the BN triple bond. Our work shows a rare example of an unsaturated BN system, serving as a platform for both the release and reduction of N2. This discovery opens new pathways and holds substantial influence on the future design of functional main group N2 species.

8.
Chem Sci ; 14(21): 5722-5727, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37265721

RESUMO

Isolable T-shaped planar pnictogen compounds R3Pn were reported more than three decades ago and have been attracting burgeoning interest in recent years; T-shaped planar group 14 anions, isoelectronic to R3Pn, however, are still unknown. Herein, we report the synthesis, full characterization, and reactivity of the first crystalline T-shaped planar group 14 anion 4 bearing a trinitrogen pincer ligand. DFT calculations indicate that the tricoordinate germanium center features both an unoccupied 4p orbital and two lone pairs of electrons. Its electron-rich nature allows for the nucleophilic attack on the methyl iodine giving methyl-substituted complex 5 and facile oxidation of the germanium center by elemental sulfur and selenium to furnish unpresented organic anions bearing terminal Ge[double bond, length as m-dash]Ch (Ch = S or Se) double bonds.

9.
Int J Mol Sci ; 24(10)2023 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-37240401

RESUMO

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA. Herein, we prepared a novel near-infrared (NIR) light-sensitive DDS (DS-TD/MPDA) by using mesoporous polydopamine nanospheres (MPDA) as NIR responders and drug carriers; diclofenac sodium (DS) as the anti-inflammatory medication; and 1-tetradecanol (TD) with a phase-inversion temperature of 39 °C as the drug administrator. Upon exposure to 808 nm NIR laser, DS-TD/MPDA could raise the temperature up to the melting point of TD through photothermal conversion, and intelligently trigger DS release. The resultant nanospheres exhibited an excellent photothermal effect and effectively controlled the release of DS through laser irradiation to accommodate the multifunctional therapeutic effect. More importantly, the biological evaluation of DS-TD/MPDA for TMJOA treatment was also performed for the first time. The experiments' results demonstrated that DS-TD/MPDA displayed a good biocompatibility in vitro and in vivo during metabolism. After injection into the TMJ of rats afflicted with TMJOA induced by unilateral anterior crossbite for 14 days, DS-TD/MPDA could alleviate the deterioration of TMJ cartilage, thus ameliorating osteoarthritis. Therefore, DS-TD/MPDA could be a promising candidate for photothermal-chemotherapy for TMJOA.


Assuntos
Nanopartículas , Nanosferas , Osteoartrite , Ratos , Animais , Osteoartrite/tratamento farmacológico , Articulação Temporomandibular , Doxorrubicina/farmacologia , Fototerapia/métodos
10.
J Bone Miner Res ; 38(4): 556-567, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36722289

RESUMO

Temporomandibular joint (TMJ) growth requires orchestrated interactions between various cell types. Recent studies revealed that fibrocartilage stem cells (FCSCs) in the TMJ cartilage play critical roles as cell resources for joint development and repair. However, the detailed molecular network that influences FCSC fate during TMJ cartilage development remains to be elucidated. Here, we investigate the functional role of Igf1 in FCSCs for TMJ cartilage growth and homeostasis by lineage tracing using Gli1-CreER+ ; Tmflfl mice and conditional Igf1 deletion using Gli1-/Col2-CreER+ ; Igf1fl/fl mice. In Gli1-CreER+ ; Tmflfl mice, red fluorescence+ (RFP+ ) FCSCs show a favorable proliferative capacity. Igf1 deletion in Gli1+ /Col2+ cell lineages leads to distinct pathological changes in TMJ cartilage. More serious cartilage thickness and cell density reductions are found in the superficial layers in Gli1-CreER+ ; Igf1fl/fl mice. After long-term Igf1 deletion, a severe disordered cell arrangement is found in both groups. When Igf1 is conditionally deleted in vivo, the red fluorescent protein-labeled Gli1+ FCSC shows a significant disruption of chondrogenic differentiation, cell proliferation, and apoptosis leading to TMJ cartilage disarrangement and subchondral bone loss. Immunostaining shows that pAkt signaling is blocked in all cartilage layers after the Gli1+ -specific deletion of Igf1. In vitro, Igf1 deletion disrupts FCSC capacities, including proliferation and chondrogenesis. Moreover, the deletion of Igf1 in FCSCs significantly aggravates the joint osteoarthritis phenotype in the unilateral anterior crossbite mouse model, characterized by decreased cartilage thickness and cell numbers as well as a loss of extracellular matrix secretions. These findings uncover Igf1 as a regulator of TMJ cartilage growth and repair. The deletion of Igf1 disrupts the progenitor capacity of FCSCs, leading to a disordered cell distribution and exaggerating TMJ cartilage dysfunction. © 2023 American Society for Bone and Mineral Research (ASBMR).


Assuntos
Cartilagem Articular , Fator de Crescimento Insulin-Like I , Articulação Temporomandibular , Animais , Camundongos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Fibrocartilagem , Homeostase , Células-Tronco , Articulação Temporomandibular/metabolismo , Proteína GLI1 em Dedos de Zinco/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo
11.
Nat Commun ; 14(1): 830, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36788226

RESUMO

The biological characteristics of the temporomandibular joint disc involve complex cellular network in cell identity and extracellular matrix composition to modulate jaw function. The lack of a detailed characterization of the network severely limits the development of targeted therapies for temporomandibular joint-related diseases. Here we profiled single-cell transcriptomes of disc cells from mice at different postnatal stages, finding that the fibroblast population could be divided into chondrogenic and non-chondrogenic clusters. We also find that the resident mural cell population is the source of disc progenitors, characterized by ubiquitously active expression of the NOTCH3 and THY1 pathways. Lineage tracing reveals that Myh11+ mural cells coordinate angiogenesis during disc injury but lost their progenitor characteristics and ultimately become Sfrp2+ non-chondrogenic fibroblasts instead of Chad+ chondrogenic fibroblasts. Overall, we reveal multiple insights into the coordinated development of disc cells and are the first to describe the resident mural cell progenitor during disc injury.


Assuntos
Matriz Extracelular , Disco da Articulação Temporomandibular , Animais , Camundongos , Disco da Articulação Temporomandibular/metabolismo , Células-Tronco
12.
Cell Prolif ; 56(1): e13342, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36162830

RESUMO

OBJECTIVE: Osteochondroma is a common benign skeletal disorder for which different molecular and histological features of long bones have been reported. We investigated cell-of-origin and molecular mechanisms of a rare condylar osteochondroma (CO). METHODS: Human fibrocartilage stem cells (hFCSCs) isolated from CO and normal condyle tissue were used for RNA sequencing, real-time PCR, Western Blotting, immunohistology, flowcytometry, as well as for chondrogenic differentiation, proliferation, and apoptosis detection assays. RESULTS: HFCSCs were fewer in number with weaker proliferative capacity and higher apoptosis ratio in the CO group. During the chondrogenic inducing process, hFCSCs from CO were prone to form more mature and hypertrophic cartilage. The result of RNA sequencing of hFCSCs from CO and normal condyle revealed a correlation between the PI3K/AKT signalling pathway and CO. Activated PI3K/AKT signalling might lead to functional changes in hFCSCs by enhancing cell apoptosis in the developmental process of CO. Increased expression of BCL2-like protein 11 (BIM) in CO tissue also supports this conclusion. Furthermore, the activation of the PI3K/AKT pathway in TMJ of mice induced histological disorder and increased apoptosis in condylar cartilage. CONCLUSION: We conclude that the activation of PI3K/AKT signalling in hFCSCs of CO suggests a new hypothesis for the cell-of-origin of human CO and another possible target to treat it.


Assuntos
Neoplasias Ósseas , Osteocondroma , Humanos , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Côndilo Mandibular , Osteocondroma/genética , Osteocondroma/metabolismo , Osteocondroma/patologia , Fibrocartilagem/metabolismo , Fibrocartilagem/patologia , Células-Tronco/metabolismo , Neoplasias Ósseas/patologia , Proliferação de Células
13.
RSC Adv ; 12(41): 26945-26952, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36320831

RESUMO

In this work, a luminescent metal-organic framework (Eu-MOF {[Eu6L6(µ3-OH)8(H2O)3]8·H2O} n ) was constructed by a solvothermal method with a linear organic ligand L (10-[(2-amino-4-carboxyl-phenyl)ethynyl]anthracene-9-carboxylic acid) based on anthracene and alkyne groups and using Eu3+ as the metal center. The MOF exhibits a stable UiO-66 crystal structure, and a six-core cluster twelve-linked secondary structural unit was successfully synthesized using 2-fluorobenzoic acid as a modulator, forming a classical fcu topology. Moreover, it exhibits good chemical stability. Interestingly, Eu-MOF exhibited high selectivity and sensitive fluorescence burst properties towards Fe3+ ions and 2,4,6-trinitrophenol (TNP) in DMF solution. For Fe3+, the K SV value is 5.06 × 105 M-1 and the LOD value is 5.1 × 10-7 M. For TNP, the K SV value is 1.92 × 104 M-1 and the LOD value is 1.93 × 10-6 M. In addition, Eu-MOF showed good anti-interference ability and fast response. This work provides an excellent fluorescent sensor for the detection of Fe3+ and 2,4,6-trinitrophenol (TNP) residues in contaminants.

14.
Dalton Trans ; 51(29): 11125-11134, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35797528

RESUMO

The active sites of [FeFe]-hydrogenase promoted by Fe/E (E = S, Se) clusters have attracted considerable interest due to their significance in understanding the interconversion of hydrogen with protons and electrons. As an extension of the study on Fe/Se clusters related to H-cluster model compounds of [FeFe]-hydrogenase, a series of tertiary phosphine substituted Fe/Se carbonyls were successfully prepared. The treatment of Fe2(µ-SePh)2(CO)6 (A) and excess PR3 resulted in the ferrous bis(selenolate) carbonyls Fe(SePh)2(CO)2(PR3)2 (PR3 = PPhMe2, 1; PMe3, 2) in moderate yields. In striking contrast, the reaction of Fe2(µ-SeCH2Ph)2(CO)6 (B) with the same PR3 ligand resulted in the PR3-disubstituted models Fe2(µ-SeCH2Ph)2(CO)4(PR3)2 (PR3 = PPhMe2, 3; PMe3, 4) as the principal products. The more interesting finding is that two independent isomers (anti- and syn-) can be isolated according to different reaction temperatures. Further reactions of 3 or 4 with PR3 under UV irradiation afforded the first PR3-trisubstituted 2Fe2Se derivatives Fe2(µ-SeCH2Ph)2(CO)3(PR3)3 (PR3 = PPhMe2, 5; PMe3, 6). 6 could be further converted into the tetrasubstituted product Fe2(µ-SeCH2Ph)2(CO)2(PMe3)4 (7), while no further substitution was observed with 5 and excess of PPhMe2. All the prepared compounds were fully characterized by elemental analysis, various spectroscopic techniques and X-ray crystallography. In addition, some electrochemical properties of these models were studied by cyclic voltammetry (CV) in MeCN. Compounds 4, 6 and 7 were found to be catalysts for the H2 evolution reaction under electrochemical conditions.


Assuntos
Hidrogenase , Proteínas Ferro-Enxofre , Cristalografia por Raios X , Hidrogênio/química , Hidrogenase/química , Proteínas Ferro-Enxofre/química , Modelos Moleculares , Prótons
15.
Dalton Trans ; 51(30): 11295-11301, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35819169

RESUMO

The incorporation of Sc3+ can stabilize calcite-phase LuBO3:Ce3+ to grow large-sized single crystals but leads to the significant degradation of scintillation performance. In the present work, alkali metal ion (A+ = Li+, Na+, K+)-incorporated (Lu, A, Sc)BO3:Ce was rapidly synthesized in batches via a high-throughput sol-gel method. The aliovalent substitution of Lu3+ with A+ is balanced by the generation of oxygen vacancies by forming complexes. Thanks to the increased oxygen vacancies, the luminescence and XEL intensity of (Lu, Li, Sc)BO3:Ce are significantly enhanced by 2.2 times and 1.9 times, respectively. Further, the incorporation of A+ is attributed to the improved transition efficiency of charge carriers. The prepared scintillation screen fabricated with LASBO:Ce and PMMA shows that the spatial resolution can reach 8.6 lp mm-1, indicating its potential application in efficient and low-cost non-destructive X-ray detection. This work is of great significance in improving the luminescence and scintillation performance of (Lu, Sc)BO3:Ce single crystals and thin films and their application in the scintillation field.

16.
Angew Chem Int Ed Engl ; 61(34): e202205814, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35713957

RESUMO

Being isoelectronic with alkynes, iminoboranes with a polar B≡N triple bond have been exclusively investigated as a potent 1,2-dipole in synthetic chemistry. Herein, we disclose the unprecedented reactivity of aryliminoboranes via the BNCC π conjugation, namely hetero-enyne behavior. This allows for facile dearomative Diels-Alder-like reactions of aryliminoboranes with aldehydes. This cycloaddition features mild conditions, is catalyst-free, and has a broad substrate scope and good functional group tolerance. Kinetic and computational studies reveal its second-order reaction and concerted cyclization mechanism. This report unveils new synthetic application of iminoboranes beyond their classical reaction patterns.

17.
Chem Sci ; 13(8): 2303-2309, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35310477

RESUMO

A cationic terminal iminoborane [Mes*N[triple bond, length as m-dash]B ← IPr2Me2][AlBr4] (3+[AlBr4]-) (Mes* = 2,4,6-tri-tert-butylphenyl and IPr2Me2 = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) has been synthesized and characterized. The employment of an aryl group and N-heterocyclic carbene (NHC) ligand enables 3+[AlBr4]- to exhibit both B-centered Lewis acidity and BN multiple bond reactivities, thus allowing for the construction of tri-coordinate boron cations 5+-12+. More importantly, initial reactions involving coordination, addition, and [2 + 3] cycloadditions have been observed for the cationic iminoborane, demonstrating the potential to build numerous organoboron species via several synthetic routes.

18.
Angew Chem Int Ed Engl ; 61(15): e202117053, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35122370

RESUMO

Although Schleyer's computations in 1979 predicted that the ground state of the parent diborirane features a planar-tetracoordinate carbon atom (anti van't Hoff-Le Bel geometry), this work demonstrates that substitution of C coupled with N-heterocyclic carbene (NHC) coordination provides access to isolable diborirane derivatives 3 and 4 with van't Hoff-Le Bel geometry. Species 3 and 4 are isoelectronic with cyclopropane and the highly strained B2 C rings feature 2c-2e bent σ bonds. Consequently, the B-B and B-C bonds in 3 are cleaved in the presence of hydride, proton, and chalcogens. The former two reactions gave NHC-coordinated fluorenyldihydridoborane 5 and dichlorofluorenylborane 6, respectively, whereas the latter transformations afforded novel thiaborirane 8 and selenaborirane 9. In addition, transfer hydrogenation of 3 with ammonia borane (H3 N⋅BH3 ) led to the formation of (µ-hydrido)diborane 7 via selective cleavage of the B-B bond. These reactivities show potential for their future application in organic synthesis.

19.
Inorg Chem ; 61(10): 4302-4311, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35212526

RESUMO

Mechanoluminescence materials that emit light under mechanical stimulation have attracted widespread attention in sensing, anticounterfeiting, and imaging applications. In this study, a series of Sr1-xBixZnSO (0.001 ≤ x ≤ 0.1) samples was synthesized by the method of high temperature solid-state reaction. It is worth noting that the distortion degree of the SrO3S3 octahedron was increased with increasing Bi3+ concentration, and the color manipulated Sr1-xBixZnSO which can emit different photoluminescence (blue to dark blue and finally red) and mechanoluminescence (orange to red) colors is obtained. Moreover, the deep traps can stably store and provide electronic supplements in shallow traps released under mechanical stimulation. Therefore, devices made of SrZnSO:Bi3+ phosphor and polydimethylsiloxane (PDMS) can be used as thermo-mechano-opto three-mode anticounterfeiting. The ML intensity is linear to the external load and can be utilized for stress sensing or imaging.

20.
Opt Express ; 29(15): 23752-23763, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34614634

RESUMO

To address the reduction in the detection efficiency of a structured CsI(Tl) scintillation screen when its structure period reaches the order of microns, a dual-periodic structure of the screen is proposed. The special feature of the dual structure is that each unit of the primary structure is divided equally into either four or nine square column-shaped scintillation sub-units. The sub-units are separated only by SiO2 layers to form a secondary structure. The results show that the performance of a dual-structure CsI(Tl) screen in X-ray imaging is much better than that of a corresponding single-structure screen.

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