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1.
Chemistry ; : e202401303, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38794842

RESUMO

Developing pragmatic strategies for accessing functional benzofuran-2-ones from 3-([1,1'-biphenyl]-2-yl)benzofuran remains an enduring challenge. Herein, we have achieved a highly discriminating electrochemical oxidative dearomative spiroannulation of 3-([1,1'-biphenyl]-2-yl)benzofuran, culminating in the synthesis of 2H-spiro[benzofuran-3,9'-fluoren]-2-one derivatives. By harnessing the electrophilic intermediates of benzofuryl radical cations supported by DFT calculations, we attain exceptional regioselectivity while eliminating the need for stoichiometric oxidants. Mechanistic investigations reveal a sequence of events involving the benzofuran radical cation, encompassing the capture of H2O, nucleophilic arene attack, and subsequent deprotonation, ultimately yielding the final benzofuran-2-ones.

2.
Chem Commun (Camb) ; 59(59): 9134-9137, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37409424

RESUMO

We synthesize a Sn-modified MIL-101(Fe), which can confine Pt to the single-atom scale. This novel Pt@MIL(FeSn) catalyst efficiently hydrogenates levulinic acid to γ-valerolactone (TOF: 1386 h-1, yield: >99%) at only 100 °C and 1 MPa of H2via α-angelica lactone as an intermediate. This could be the first report on switching the reaction path from 4-hydroxypentanoic acid to α-angelica lactone under very mild conditions. Incorporating Sn into MIL-101(Fe) enables the creation of abundant micro-pores less than 1 nm and Lewis acidic sites that stabilize Pt0 atoms. The ensemble of active Pt atoms and a Lewis acid can synergistically enhance adsorption of the CO bond and facilitate dehydrative cyclization of levulinic acid.

3.
Asian J Surg ; 46(4): 1550-1555, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36085124

RESUMO

Parathyroid gland transplantation into the sternocleidomastoid muscle is effective, but it is not possible to confirm transplant survival with this method. In this study, we evaluated parathyroid autotransplantation into the brachioradialis muscle and its survival rate. OBJECTIVES: To evaluate autologous parathyroid gland left forearm brachioradial muscle transplantation and its survival rate. SUMMARY BACKGROUND DATA: The most commonly used transplantation site is the sternocleidomastoid muscle, but transplant survival cannot be confirmed using this method. Autologous parathyroid gland left forearm brachioradial muscle transplantation solves this problem, and we evaluate the transplant survival using this method. METHODS: We followed-up patients who underwent thyroidectomy and autologous parathyroid left forearm brachioradial muscle transplantation in our center from September 2013 to January 2018. The last follow-up date was January 2021; all enrolled patients underwent at least 3 years of follow-up. We calculated the transplant survival rate at several time points. RESULTS: We evaluated 238 transplanted cases, for which the long-term survival rate was 85.7% (204/238), and the short-term survival rate was 86.1% (205/238). Sixty-five cases had two parathyroid glands transplanted into the left forearm brachioradialis muscle. The long-term survival rate was 92.3% (60/65), and the short-term survival rate was 95.4% (62/65). CONCLUSIONS: Autologous parathyroid gland left brachioradialis transplantation is a reliable, measurable method with good survival rate, and we recommend this method for consideration for transplanting parathyroid glands in thyroidectomy.


Assuntos
Hipoparatireoidismo , Glândulas Paratireoides , Humanos , Glândulas Paratireoides/transplante , Seguimentos , Antebraço/cirurgia , Transplante Autólogo/métodos , Tireoidectomia/métodos
4.
iScience ; 25(3): 103906, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35243259

RESUMO

Presented here is a copper-catalyzed, aerobic oxidative C-H/C-H cyclization reaction, which occurs by cleaving the C-H and N-H bonds of 3-phenylindoles. A broad range of 3-phenylindoles can be well tolerated to produce the indole-containing polycyclic aromatic hydrocarbons (PAH) in good to excellent yields. An evaluation of the reaction mechanism is enabled by the isolation of the di- and tri-indole intermediates, highlighting the role of the substrate for this catalytic reaction. The results of these controlled experiments and kinetic studies provide solid experimental support for a self-catalysis reaction, which has rarely been observed in oxidative C-H activation reactions. Additional mechanistic studies indicate that the substrate for this reaction accelerates by the following mechanism: The substrate combines with the Cu catalyst to transform the less active di-indole intermediate into a tri-indole intermediate. This intermediate is quickly converted into the desired product along with regeneration of the substrate copper complex.

5.
Cell Death Discov ; 8(1): 21, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35022405

RESUMO

Papillary thyroid cancer (PTC) is a common endocrine tumor with a rapidly increasing incidence in recent years. Although the majority of PTCs are relatively indolent and have a good prognosis, a certain proportion is highly aggressive with lymphatic metastasis, iodine resistance, and easy recurrence. Circular RNAs (circRNAs) are a class of noncoding RNAs that are linked to a variety of tumor processes in several cancers, including PTC. In the current study, circRNA high-throughput sequencing was performed to identify alterations in circRNA expression levels in PTC tissues. circTIAM1 was then selected because of its increased expression in PTC and association with apoptosis, proliferation, and migration of PTC cells in vitro and in vivo. Mechanistically, circTIAM1 acted as a sponge of microRNA-646 and functioned in PTC by targeting miR-646 and heterogeneous ribonucleoprotein A1. Fluorescence in situ hybridization and dual-luciferase reporter assays further confirmed these connections. Overall, our results reveal an important oncogenic role of circTIAM1 in PTC and may represent a potentially therapeutic target against PTC progression.

6.
Chem Commun (Camb) ; 49(59): 6626-8, 2013 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-23770710

RESUMO

Palladium (Pd) nanocatalysts with high energy facets {110} supported on flower-like hydroxyapatite (F-HAP) were successfully prepared. Based on the experimental data and theoretical calculations, it was found that the O2 dissociation on Pd {110} facets could be key to the performance of Pd nanoparticles in the solvent-free selective oxidation of alcohols.


Assuntos
Álcoois/química , Durapatita/síntese química , Nanopartículas Metálicas/química , Oxigênio/química , Paládio/química , Durapatita/química , Oxirredução , Tamanho da Partícula , Propriedades de Superfície
7.
J Colloid Interface Sci ; 333(1): 317-23, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19246048

RESUMO

We report a modified method to synthesize SBA-16 mesostructured silica under refluxing condition using block co-polymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (F127) as template, cetyltrimethylammonium bromide (CTAB) as co-template, and tetraethyl orthosilicate (TEOS) as silica source. The physiochemical properties of SBA-16 silica were characterized by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and (29)Si solid-state nuclear magnetic resonance (NMR). The resulting SBA-16 silica exhibited highly ordered mesoporous structure, mono-dispersed spherical morphology, excellent hydrothermal, thermal and mechanical stabilities. It was worth mentioning that the synthesis time can be significantly reduced from 48 h to 8 h, which opened a feasible way to produce SBA-16 silica in a large scale. Moreover, the "super-cage" pore structure of SBA-16 encapsulated gold nanoparticles in a "ship in a bottle" way. The well-confined gold nanoparticles (mean size of 5 nm) with a narrow particle size distribution were highly active in solvent-free benzyl alcohol selective oxidation with molecular oxygen.

9.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 2): m327, 2008 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-21201295

RESUMO

In the title compound, [Co(C(7)H(5)O(2))(2)(C(14)H(12)N(2))], the Co(II) ion is located on a twofold rotation axis and is chelated by a 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and two benzoate anions in a distorted octa-hedral geometry. The crystal packing is stabilized by π-π inter-actions between parallel dmphen ligands of neighbouring mol-ecules, with a face-to-face distance of 3.411 (2) Å.

10.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 5): m740, 2008 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-21202260

RESUMO

In the title compound, [Co(C(7)H(5)O(3))(2)(C(14)H(12)N(2))], the Co(II) ion is five-coordinated by two N atoms from one 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and three O atoms from two 2-hydroxy-benzoate anions in a distorted trigonal bipyramidal geometry. The carboxyl-ate group of one of the two 2-hydroxy-benzoate anions is monodentate with a normal Co-O distance [1.9804 (18) Å], while the other is bidentate with two longer Co-O bonds [2.1981 (18) and 2.1359 (19) Å]. The crystal structure is stabilized by aromatic π-π stacking inter-actions [centroid-centroid distances of 4.0380 (3) and 3.8216 (3) Šbetween dmphen/dmphen and benzene/dmphen rings, respectively] and C-H⋯π(benzene) inter-actions.

11.
Chem Commun (Camb) ; (4): 440-1, 2004 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-14765248

RESUMO

Co2+-exchanged faujasite zeolites can efficiently catalyze the epoxidation of styrene with molecular oxygen, and the Co2+ ions located in supercages are suggested to account for the activation of O2 for the epoxidation of styrene.

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