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1.
Nat Prod Res ; : 1-7, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38742433

RESUMEN

Two new bicyclic sesquiterpenes,Δ9-2, 5, 11-trihydroxyl-ß-cis-bergamotene (3) and Nigrohydroin A (4), together with ten known compounds (1, 2 and 5-12) were obtained from endophytic fungus Nigrospora sp. E121. The structures were elucidated on the basis of their 1D and 2D NMR spectra and mass spectrometric data. The possible biosynthetic pathway of compounds 1, 2, 3 and 4 in Nigrospora sp. E121were reported according to literature. The phytotoxic assay results indicated that the acetyl fragment in α-acetylorcinol may contribute to the phytotoxic activity of this compound.

2.
Nat Commun ; 15(1): 1566, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38378699

RESUMEN

Two-dimensional (2D) transition metal nitrides and carbides (MXenes), represented by Ti3C2Tx, have broad applications in flexible electronics, electromechanical devices, and structural membranes due to their unique physical and chemical properties. Despite the Young's modulus of 2D Ti3C2Tx has been theoretically predicted to be 0.502 TPa, which has not been experimentally confirmed so far due to the measurement is extremely restricted. Here, by optimizing the sample preparation, cutting, and transfer protocols, we perform the direct in-situ tensile tests on monolayer Ti3C2Tx nanosheets using nanomechanical push-to-pull equipment under a scanning electron microscope. The effective Young's modulus is 0.484 ± 0.013 TPa, which is much closer to the theoretical value of 0.502 TPa than the previously reported 0.33 TPa by the disputed nanoindentation method, and the measured elastic stiffness is ~948 N/m. Moreover, during the process of tensile loading, the monolayer Ti3C2Tx shows an average elastic strain of ~3.2% and a tensile strength as large as ~15.4 GPa. This work corrects the previous reports by nanoindentation method and demonstrates that the Ti3C2Tx indeed keeps immense potential for broad range of applications.

3.
ACS Appl Mater Interfaces ; 15(36): 42845-42853, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37644617

RESUMEN

Metal-organic frameworks (MOFs), synthesized by the self-assembly of organic ligands and metal centers, are structurally designable materials. In the current study, first-principles calculation based on density functional theory (DFT) was performed to investigate the intrinsic mechanical and electrical properties and mechanical-electrical coupling behavior of MOF-5. To improve the conductivity of MOF-5, homologous elements of Cu, Ag, and Au were adopted to replace the Zn atom in MOF-5, reducing the band gap and improving its electrical performance. Cu-MOF-5 and Au-MOF-5, with stable structures, exhibit better conductivity. The intrinsic mechanical properties such as independent elastic constants of MOF-5 and M-MOF-5 (M = Cu, Ag, Au) were obtained. MOF-5 and Cu-MOF-5 were experimentally synthesized to demonstrate the reduction in the band gap after metal substitution. The study of the strain effect of MOF-5 and Cu-MOF-5 proves that strain engineering is an effective method to regulate the band gap and this modulation is repeatable. This study clarifies the tunability of the band gap of MOF-5 with metal substituents and provides an efficient strategy for the development of new types of MOFs with desired physical properties using the combination of theoretical prediction and experimental synthesis and validation.

4.
ACS Omega ; 8(8): 7690-7698, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36872994

RESUMEN

Manganese dioxide and its derivatives are widely used as promising electrode materials for supercapacitors. To achieve the environmentally friendly, simple, and effective material synthesis requirements, the laser direct writing method is utilized to pyrolyze the MnCO3/carboxymethylcellulose (CMC) precursors to MnO2/carbonized CMC (LP-MnO2/CCMC) in a one-step and mask-free way successfully. Here, CMC is utilized as the combustion-supporting agent to promote the conversion of MnCO3 into MnO2. The selected materials have the following advantages: (1) MnCO3 is soluble and can be converted into MnO2 with the promotion of a combustion-supporting agent. (2) CMC is an eco-friendly and soluble carbonaceous material, which is widely used as the precursor and combustion-supporting agent; (3) the redundant part of the MnCO3/CMC precursor can be removed by deionized water, which is simple and convenient. The different mass ratios of MnCO3 and CMC-induced LP-MnO2/CCMC(R1) and LP-MnO2/CCMC(R1/5) composites are investigated in the electrochemical performance toward electrodes, respectively. The LP-MnO2/CCMC(R1/5)-based electrode showed the high specific capacitance of 74.2 F/g (at the current density of 0.1 A/g) and good electrical durability for 1000 times charging-discharging cycles. Simultaneously, the sandwich-like supercapacitor which was assembled by LP-MnO2/CCMC(R1/5) electrodes presents the maximum specific capacitance of 49.7 F/g at the current density of 0.1 A/g. Moreover, the LP-MnO2/CCMC(R1/5)-based energy supply system is used to light a light-emitting diode, which demonstrates the great potential of LP-MnO2/CCMC(R1/5)-based supercapacitors for power devices.

5.
Materials (Basel) ; 15(23)2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36500055

RESUMEN

The equiatomic CoCrFeNiMn high-entropy alloy (HEA) possesses excellent properties including exceptional strength-ductility synergy, high corrosion resistance, and good thermal stability. Selective laser melting (SLM) additive manufacturing facilitates the convenient fabrication of the CoCrFeNiMn HEA parts with complex geometries. Here, the SLM process optimization was conducted to achieve a high relative density of as-built CoCrFeNiMn HEA bulks. The mechanisms of process-induced defects and process control were elucidated. The microscale mechanical behaviors were analyzed through in situ scanning electron microscopy observation during the compression tests on micro-pillars of the as-built HEA. The stress-strain characteristics by repeated slip and mechanism of "dislocation avalanche" during the compression of micro-pillars were discussed. The high-cycle fatigue tests of the as-built HEA were performed. It was found that a large number of nano-twins were induced by the fatigue, causing a non-negligible cycle softening phenomenon. The effects of promoted ductility due to the fatigue-induced nano-twins were illustrated. This work has some significance for the engineering application of the SLM additively manufactured CoCrFeNiMn HEA parts.

6.
Front Psychiatry ; 13: 926251, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35958660

RESUMEN

A considerable number of patients suffer from adverse metabolic reactions caused by atypical antipsychotics (AAPs), however, current management strategies are disappointing to clinicians. Preclinical studies have consistently demonstrated that intermittent fasting (IF) has robust disease-modifying efficacy in animal models in a wide range of pathological conditions, especially obesity and diabetes. However, it is unclear what role IF can play in addressing AAPs-induced metabolic disturbances. In our study, we found that a 5:2 IF regimen significantly ameliorated the metabolic disturbances induced by olanzapine (a drug representative of AAPs) in animal models. Meanwhile, our research suggests that IF altering food intake during the refeeding phase may account for the metabolic benefit. This study provides supporting evidence regarding a potentially cost-effective intervention strategy for AAPs-induced metabolic disturbances.

7.
Sci Rep ; 10(1): 15823, 2020 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-32978476

RESUMEN

Cancer therapy is one of the most important challenges in clinical medicine. So far different methods have been developed for cancer therapy, such as radiation therapy, surgery, chemotherapy and photodynamic therapy. Here we propose a new concept for cancer therapy, i.e., killing the cancer cells simply via reactive oxygen species (ROS) generated by TiO2-Pd/graphene composites. Activated by animal heat of 37 °C, the electrons in the valence band can be excited to the conduction band of TiO2 via the energy levels of Pd species and graphene, generating ROS without light irradiation or electric excitation. The tumors in BALB/c mice are successfully regressed at animal heat without any other external conditions, such as radiation, UV, visible and IR irradiation. Our results suggest that the design of animal heat activated cancer therapy is a feasible concept for practical applications of cancer treatments.


Asunto(s)
Grafito/química , Calor , Neoplasias Pulmonares/terapia , Nanopartículas del Metal/administración & dosificación , Paladio/química , Fotoquimioterapia , Titanio/química , Animales , Apoptosis , Catálisis , Proliferación Celular , Humanos , Neoplasias Pulmonares/patología , Nanopartículas del Metal/química , Ratones , Ratones Endogámicos BALB C , Especies Reactivas de Oxígeno/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Nanoscale ; 10(5): 2659, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29360114

RESUMEN

Correction for 'TiO2/vanadate (Sr10V6O25, Ni3V2O8, Zn2V2O7) heterostructured photocatalysts with enhanced photocatalytic activity for photoreduction of CO2 into CH4' by Yabin Yan et al., Nanoscale, 2016, 8, 949-958.

9.
J Colloid Interface Sci ; 486: 176-183, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-27701015

RESUMEN

A series of TiO2-N/SnO2X heterostructure photocatalysts were synthesized by a hydrolysis-deposition method. The structure, existing states of N and SnO2 heterostructure at the interface of TiO2-N/SnO2X were studied by EADX, XRD, Raman, FT-IR, XPS, and HRTEM. The band structure is investigated by both theoretical calculation and experiment characterization. It was found that the introduction of NOx surface species and SnO2 nanoparticles would enhance the absorption in visible region, increase reactive oxidative species and separate photogenerated electrons and holes efficiently. Therefore, the photocatalytic activity is improved significantly for TiO2-N/SnO2X, compared with TiO2-N and TiO2 under visible and UV light irradiation. This work may offer a new strategy to fabricate new photocatalyst with high photocatalytic performance.

10.
Nanoscale ; 8(2): 949-58, 2016 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26662343

RESUMEN

A series of TiO2/vanadate (Sr10V6O25, Ni3V2O8, Zn2V2O7) heterostructured photocatalysts were prepared by a simple sol-gel method. The theoretical calculations imply the possible energy band match between TiO2 and vanadates. Characterized by XRD, Raman, TEM, EDX, XPS, absorption spectra, PL and time-resolved PL decay curves, it is revealed that the vanadates, which exist on the surface of TiO2, could suppress the recombination of charge carriers, prolong the life-time of photogenerated electrons and provide surface reactive hole sites, improving the photocatalytic activity for photo-reduction of CO2 into CH4.

11.
Cancer Cytopathol ; 123(7): 421-7, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25955972

RESUMEN

BACKGROUND: Current cervical cancer screening guidelines recommend screening with a Papanicolaou (Pap) test or by cotesting (Pap and human papillomavirus [HPV]). Given the importance of high-risk HPV (hrHPV) infection in the development of cervical cancer, some studies are now suggesting the use of primary hrHPV testing as a possible screening modality. To gain further insight into the role of both Pap testing and hrHPV testing, the authors examined prior screening results in a population of Chinese patients with invasive cervical carcinoma. METHODS: Cases with a histologic diagnosis of invasive cervical carcinoma were retrieved from the Obstetrics and Gynecology Hospital of Fudan University from January 2011 to October 2014. Prior hrHPV testing and Pap test results within 3 years before the cancer diagnosis were recorded. RESULTS: Of 3714 patients with invasive cervical carcinoma, over a 46-month period, 525 had prior hrHPV testing using Hybrid Capture 2 within 3 years and 238 patients had Pap cytology testing within 1 year before the histological diagnosis. Within the 1-year period before diagnosis, the overall hrHPV-negative rate was 15.5% (74 of 477 patients) and the Pap-negative rate was also 15.5% (37 of 238 patients). Only 9 of 231 patients with both hrHPV testing and Pap testing (3.9%) had a double-negative result. Compared with squamous cell carcinoma, adenocarcinoma has significantly higher rates of prior negative results with both hrHPV and Pap cytology. CONCLUSIONS: The results of the current study demonstrated prior results of hrHPV testing and Pap cytology in a population of women in China who had not undergone intensive prior screening. Both hrHPV testing and Pap cytology were found to have similar negative rates in this population and, not surprisingly, there were fewer women who had negative testing results using both testing modalities.


Asunto(s)
Detección Precoz del Cáncer/métodos , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/diagnóstico , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virología , Adulto , Distribución por Edad , Anciano , China/epidemiología , Estudios de Cohortes , Bases de Datos Factuales , Femenino , Hospitales Especializados , Humanos , Incidencia , Persona de Mediana Edad , Invasividad Neoplásica/patología , Prueba de Papanicolaou/métodos , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/patología , Estudios Retrospectivos , Medición de Riesgo , Neoplasias del Cuello Uterino/patología , Frotis Vaginal , Adulto Joven
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