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1.
Nanotechnology ; 33(13)2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-34937010

RESUMEN

Defect engineering have profound influence on the energy storage properties of electrode hybrids by adjusting their intrinsic electronic characteristics. For iron carbide based materials, however, the effect of defect (especially cation vacancies) toward their electrochemical performance are still unclear. Herein, the feasible and scalable synthesis of FexC@NC with 3D honeycomb-like carbon architecture and abundant Fe vacancies via template etching is reported. Such structure enable outstanding lithium-ion storage properties owing to hierarchical pores, improved intrinsic electrochemical activity, as well as the introduction of more active sites. As a result, the FexC@NC-2 presents a high reversible specific capacity of 1079 mAh g-1after 1000 cycles. Moreover, an excellent cycling stability can be achieved via maintaining a high-capacity retention (689 mAh g-1, 98.4%) over 1000 cycles at 5 A g-1. This study provides a feasible strategy for developing high-performance hybrids with hierarchical pore and rich defects structures.

2.
Appl Spectrosc ; 74(11): 1365-1373, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32748642

RESUMEN

Many foodstuffs are extremely susceptible to contamination with aflatoxins, in which aflatoxin B1 is highly toxic and carcinogenic. Therefore, it is crucial to develop a rapid and effective analytical method for detecting and monitoring aflatoxin B1 in food. Herein, a surface-enhanced Raman spectroscopic (SERS) method combined with QuEChERS (quick, easy, cheap-effective, rugged, safe) sample pretreatment technique was used to detect aflatoxin B1. Sample preparation was optimized into a one-step extraction method using an Au nanoparticle-based solution (Au sol) as the SERS detection substrate. An affordable portable Raman spectrometer was then used for rapid, label-free, quantitative detection of aflatoxin B1 levels in foodstuffs. This method showed a good linear log relationship between the Raman signal intensity of aflatoxin B1 in the 1-1000 µg L-1 concentration range with a limit of detection of 0.85 µg kg-1 and a correlation coefficient of 0.9836. Rapid aflatoxin B1 detection times of ∼10 min for wheat, corn, and protein feed powder samples were also achieved. This method has high sensitivity, strong specificity, excellent stability, is simple to use, economical, and is suitable for on-site detection, with good prospects for practical application in the field of food safety.


Asunto(s)
Aflatoxina B1/análisis , Contaminación de Alimentos/análisis , Inocuidad de los Alimentos/métodos , Triticum/química , Zea mays/química , Oro/química , Límite de Detección , Nanopartículas del Metal/química , Espectrometría Raman
3.
ACS Appl Mater Interfaces ; 12(22): 24726-24736, 2020 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-32374149

RESUMEN

Suitable intercalation cathodes and fundamental insights into the Zn-ion storage mechanism are the crucial factors for the booming development of aqueous zinc-ion batteries. Herein, a novel nickel vanadium oxide hydrate (Ni0.25V2O5·0.88H2O) is synthesized and investigated as a high-performance electrode material, which delivers a reversible capacity of 418 mA h g-1 with 155 mA h g-1 retained at 20 A g-1 and a high capacity of 293 mA h g-1 in long-term cycling at 10 A g-1 with 77% retention after 10,000 cycles. More importantly, multistep phase transition and chemical-state change during intercalation/deintercalation of hydrated Zn2+ are illustrated in detail via in situ/ex situ analytical techniques to unveil the Zn2+ storage mechanism of the hydrated and layered vanadium oxide bronze. Furthermore, morphological development from nanobelts to hierarchical structures during rapid ion insertion and extraction is demonstrated and a self-hierarchical process is correspondingly proposed. The unique evolutions of structure and morphology, together with consequent fast Zn2+ transport kinetics, are of significance to the outstanding zinc storage capacity, which would enlighten the mechanism exploration of the aqueous rechargeable batteries and push development of vanadium-based cathode materials.

4.
Molecules ; 22(11)2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29104267

RESUMEN

Studies examining the use of essential oils as replacements for synthetic insecticides require an understanding of the contribution of each constituent present, interactions among these components, and how they relate to overall toxicity. In the present study, the chemical composition of commercial thyme oil was identified by gas chromatography-mass spectrometry. Thyme oil and blends of its major constituents were tested for their acaricidal activitities against carmine spider mites (Tetranychus cinnabarinus (Boisduval)) using a slide-dip bioassay. Natural thyme oil showed greater toxicity than any single constituent or blend of constituents. Thymol was the most abundant component (34.4%), and also possessed the strongest acaricidal activity compared with other single constituents. When tested individually, four constituents (linalool, terpinene, p-cymene and carvacrol) also had activity, while α-pinene, benzoic acid and ethyl gallate had almost no activity. The toxicity of blends of selected constituents indicated a synergistic effect among the putatively active and inactive constituents, with the presence of all constituents necessary to reach the highest toxicity. The results indicated that thyme oil and some of its major constituents have the potential to be developed into botanical acaricides.


Asunto(s)
Acaricidas/química , Acaricidas/farmacología , Aceites Volátiles/química , Aceites Volátiles/farmacología , Tetranychidae/efectos de los fármacos , Thymus (Planta)/química , Monoterpenos Acíclicos , Animales , Carmín/química , Carmín/farmacología , Cimenos , Monoterpenos/química , Monoterpenos/farmacología , Aceites de Plantas/química , Timol/química , Timol/farmacología
5.
J Huazhong Univ Sci Technolog Med Sci ; 36(3): 356-363, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27376803

RESUMEN

Hydrogen peroxide (H2O2) and free radicals cause oxidative stress, which induces cellular injuries, metabolic dysfunction, and even cell death in various clinical abnormalities. Fullerene (C60) is critical for scavenging oxygen free radicals originated from cell metabolism, and reduced glutathione (GSH) is another important endogenous antioxidant. In this study, a novel water-soluble reduced glutathione fullerene derivative (C60-GSH) was successfully synthesized, and its beneficial roles in protecting against H2O2-induced oxidative stress and apoptosis in cultured HEK 293T cells were investigated. Fourier Transform infrared spectroscopy and (1)H nuclear magnetic resonance were used to confirm the chemical structure of C60-GSH. Our results demonstrated that C60-GSH prevented the reactive oxygen species (ROS)-mediated cell damage. Additionally, C60-GSH pretreatment significantly attenuated H2O2-induced superoxide dismutase (SOD) consumption and malondialdehyde (MDA) elevation. Furthermore, C60-GSH inhibited intracellular calcium mobilization, and subsequent cell apoptosis via bcl-2/bax-caspase-3 signaling pathway induced by H2O2 stimulation in HEK 293T cells. Importantly, these protective effects of C60-GSH were superior to those of GSH. In conclusion, these results suggested that C60-GSH has potential to protect against H2O2-induced cell apoptosis by scavenging free radicals and maintaining intracellular calcium homeostasis without evident toxicity.


Asunto(s)
Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Fulerenos/farmacología , Glutatión/farmacología , Peróxido de Hidrógeno/antagonistas & inhibidores , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Calcio/metabolismo , Caspasa 3/genética , Caspasa 3/metabolismo , Supervivencia Celular/efectos de los fármacos , Fulerenos/química , Regulación de la Expresión Génica , Glutatión/análogos & derivados , Células HEK293 , Humanos , Peróxido de Hidrógeno/farmacología , Transporte Iónico/efectos de los fármacos , Malondialdehído/antagonistas & inhibidores , Malondialdehído/metabolismo , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Superóxido Dismutasa/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo
6.
Artículo en Inglés | MEDLINE | ID: mdl-22038357

RESUMEN

This study explored the possibility that the components in melanoma cytoplasm induce murine BMSCs transformation and expression of Melan-A by morphologically observing the changes of BMSCs and immunocytochemically detecting Melan-A in the cells after culturing BMSCs in medium containing melanoma cytoplasm components (MCC). MCC of B16 melanoma cells was prepared and BMSCs were cultured and induced by adding the MCC into culture medium. The cells were morphologically observed and Melan-A was immunohistochemically detected to confirm BMSCs transformation. MCC-induced BMSCs underwent morphological changes. A number of melanin granules appeared in the cytoplasm of the cells and some were released into surrounding areas. Several cells that might come from one cell formed a cluster, and their granules, together with those secreted by other induced BMSCs, formed a so-called "sphere-formed structure". The induced BMSCs expressed Melan-A. We are led to conclude that there might be some factors in the cytoplasm of melanoma cells that might induce BMSCs transformation toward melanogenic cell, or even melanoma.


Asunto(s)
Transformación Celular Neoplásica/patología , Citoplasma/química , Antígeno MART-1/metabolismo , Melanoma Experimental/patología , Neoplasias Cutáneas/patología , Células Madre/citología , Animales , Células de la Médula Ósea/citología , Línea Celular Tumoral , Transformación Celular Neoplásica/metabolismo , Técnicas de Cocultivo , Humanos , Masculino , Melanoma Experimental/química , Ratones , Neoplasias Cutáneas/química
7.
J Huazhong Univ Sci Technolog Med Sci ; 29(4): 409-12, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19662352

RESUMEN

This study investigated the ability of millimeter-wave (MMW) to promote the differentiation of bone marrow stromal cells (BMSCs) into cells with a neural phenotype. The BMSCs were primarily cultured. At passage 3, the cells were induced by beta-mercaptoethanol (BME) in combination with MMW or BME alone. The expressions of nucleostemin (NS) and neuron-specific enolase (NSE) were detected by immunofluorescent staining and Western blotting respectively to identify the differentiation. The untreated BMSCs predominately expressed NS. After induced by BME and MMW, the BMSCs exhibited a dramatic decrease in NS expression and increase in NSE expression. The differentiation rate of the cells treated with BME and MMW in combination was significantly higher than that of the cells treated with BME alone (P<0.05). It was concluded that MMW exposure enhanced the inducing effect of BME on the differentiation of BMSCs into cells with a neural phenotype.


Asunto(s)
Células de la Médula Ósea/efectos de la radiación , Diferenciación Celular/efectos de la radiación , Microondas , Neuronas/citología , Células del Estroma/efectos de la radiación , Animales , Células de la Médula Ósea/citología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Mercaptoetanol/farmacología , Fenotipo , Ratas , Células del Estroma/citología
8.
J Huazhong Univ Sci Technolog Med Sci ; 29(3): 330-4, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19513616

RESUMEN

This study examined the expression of connexin and protease-activated receptor 3 (par-3) in the distal resection margin of rectal cancer and the correlation of the expression of the two proteins with tumor relapse. A total of 40 patients with rectal cancer underwent ultra-low anterior resection with curved cutter stapler. The pathological specimens were divided into 3 groups in terms of sampling sites: tumor group, 2.0-cm group (in which the tissues were harvested 2.0 cm distal to the tumor tissues), 3.0-cm group (in which the tissues were taken 3.0 cm away from the tumor tissues). All the samples were pathologically observed and then measured for the expression of connexin and par-3 by employing immunohistochemistry and Western blotting. The operations in this series went uneventfully. No anastomotic stoma bleeding, stenosis and death occurred postoperatively. Histopathologically, in the tumor group, epithelial cells lost normal pattern of arrangement and polarity, and were loosely connected and even detached. In the 3.0-cm group, the epithelia had normal appearance, obvious cell polarity and essentially intact cell junction. Immunohistochemistry and Western blotting indicated that the 3.0-cm group had the strongest expression of connexin and par-3, and the expression in the 2.0-cm group and the tumor group was relatively weak. There existed significant difference in the expression of the two proteins among the three groups (P<0.05 for all). It was concluded that the down-regulated connexin and par-3 in the distal margin of rectal cancer tissues may indicate the progression of the disease and high likelihood of recurrence and metastasis. Although no tumor cells were found in the sections of the 2.0-cm group, the decreased expression of connexin and par-3 may suggest the development of anaplasia and the increased odds of tumor relapse. Therefore, we are led to speculate that tumor resection only including 2.0 cm of unaffected rectum could not completely avoid the distant metastasis and local relapse.


Asunto(s)
Conexinas/metabolismo , Receptores de Trombina/metabolismo , Neoplasias del Recto/metabolismo , Engrapadoras Quirúrgicas , Conexinas/genética , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Receptores de Trombina/genética , Neoplasias del Recto/cirugía , Recto/metabolismo
9.
Artículo en Chino | MEDLINE | ID: mdl-17969524

RESUMEN

OBJECTIVE: To investigate the expression of FasL and ICAM-1 on the HEVs in the hypertrophic tonsils and its clinical significance. METHOD: Under the light microscopy, HE and immunohistochemistry methods were used to show the morphology of HEVs, the number of T, B lymphocytes, the expression intensity of FasL and ICAM-1 in 17 patients with the idiopathic tonsillar hypertrophy (ITH) and in 20 patients with the chronic hypertrophic tonsillitis (CHT). RESULT: The expression intensity of ICAM-1 on the tonsillar HEVs in ITH group was significantly lower than that in CTH group (P < 0.05), but the intensity of FasL in ITH group was significantly higher than that in CHT group (P < 0.05). CONCLUSION: FasL and ICAM-1 expression in the tonsillar HEVs contribute to the CHT and ITH. The former mainly makes IHT developed, and the latter promotes the process of the inflammation.


Asunto(s)
Proteína Ligando Fas/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Tonsila Palatina/metabolismo , Tonsilitis/metabolismo , Vénulas/metabolismo , Adolescente , Linfocitos B/inmunología , Niño , Preescolar , Endotelio/irrigación sanguínea , Femenino , Humanos , Hipertrofia , Masculino , Tonsila Palatina/patología , Linfocitos T/inmunología
10.
Neurosci Lett ; 429(2-3): 81-6, 2007 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-18022764

RESUMEN

Oxidized glutathione C(60) derivative has been synthesized and characterized in our research. As a novel derivative of C(60), the glutathione C(60) derivative is soluble in dimethylsulfoxide, dimethylformamide and dimethylacetamide. Rat pheochromocytoma (PC12) cells are treated with hydrogen peroxide and underwent cytotoxicity; apoptotic death is determined by MTT assay, flow cytometry analysis, PI/Hoechst 33342 staining and glutathione assay. The results suggest that glutathione C(60) derivative has the potential to prevent oxidative stress-induced cell death without evident toxicity.


Asunto(s)
Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Fulerenos/farmacología , Glutatión/análogos & derivados , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Animales , Antioxidantes/síntesis química , Apoptosis/fisiología , Bencimidazoles/química , Bioensayo , Citotoxinas/antagonistas & inhibidores , Citotoxinas/toxicidad , Dimerización , Citometría de Flujo , Fulerenos/química , Glutatión/síntesis química , Glutatión/farmacología , Peróxido de Hidrógeno/antagonistas & inhibidores , Peróxido de Hidrógeno/toxicidad , Estructura Molecular , Degeneración Nerviosa/tratamiento farmacológico , Degeneración Nerviosa/metabolismo , Degeneración Nerviosa/fisiopatología , Neuronas/metabolismo , Neuronas/patología , Fármacos Neuroprotectores/síntesis química , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Células PC12 , Ratas , Sales de Tetrazolio/química
11.
World J Gastroenterol ; 9(2): 267-70, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12532445

RESUMEN

AIM: To investigate the serum level and expression of insulin growth factor II (IGF-II) in liver tissues of rats with early experimental hepatocellular carcinomas (HCC) and its significance in early diagnosis. METHODS: Early experimental hepatocellular carcinomas were induced by diethylnitrosamine (DENA) in 180 male SD rats. Another 20 male SD rats served as control. The IGF-II serum level was measured by ELISA. Immunohistochemistry and electron microscopic immunohistochemistry were used to observe the expression of IGF-II in normal and tumor liver tissues and its ultrastructural location in malignant hepatocytes. The expressions of IGF-II in human hepatoma cell lines HepG2, SMMC7721 and human embryonic liver cell line L-02 were measured by immunocytochemistry. IGF-II mRNA level was studied by in situ hybridization. RESULTS: IGF-II was expressed in the cytoplasm of both sinusoidal cells in paracancerous cirrhotic liver tissue and malignant hepatocytes in early experimental HCC tissues. Gold particles were seen on the rough endoplasmic reticulum and the mitochondrion in malignant hepatocytes. IGF-II was expressed in the human hepatoma cell lines. The mRNA level of IGF-II was higher in rat liver tumor tissue than in normal rat liver tissue. The serum IGF-II level of the early experimental HCC group was 34.67+/-10.53 ng.ml(-1) and that of the control group was 11.75+/-5.84 ng.ml(-1). The rank sum test was used for statistical analysis. There was a significant difference between the two groups (P<0.01). CONCLUSION: During the induction of early experimental HCC by DENA, IGF-II may promote hepatocytic proliferation via a paracrine mechanism in the pre-cancerous stage. When hepatocytes are transformed into malignant cells, they may secrete IGF-II and promote malignant cell proliferation by an autocrine mechanism. IGF-II may be a possible biological marker in the early diagnosis of HCC.


Asunto(s)
Factor II del Crecimiento Similar a la Insulina/metabolismo , Neoplasias Hepáticas Experimentales/metabolismo , Animales , Humanos , Neoplasias Hepáticas Experimentales/diagnóstico , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Células Tumorales Cultivadas/metabolismo
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