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2.
ACS Appl Energy Mater ; 6(21): 10883-10896, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-38020741

RESUMO

Increasing the power conversion efficiency (PCE) of kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells has remained challenging over the past decade, in part due to open-circuit voltage (VOC)-limiting defect states at the absorber/buffer interface. Previously, we found that substituting the conventional CdS buffer layer with In2S3 in CZTSSe devices fabricated from nanoparticle inks produced an increase in the apparent doping density of the CZTSSe film and a higher built-in voltage arising from a more favorable energy-band alignment at the absorber/buffer interface. However, any associated gain in VOC was negated by the introduction of photoactive defects at the interface. This present study incorporates a hybrid Cd/In dual buffer in CZTSSe devices that demonstrate an average relative increase of 11.5% in PCE compared to CZTSSe devices with a standard CdS buffer. Current density-voltage analysis using a double-diode model revealed the presence of (i) a large recombination current in the quasi-neutral region (QNR) of the CZTSSe absorber in the standard CdS-based device, (ii) a large recombination current in the space-charge region (SCR) of the hybrid buffer CZTSSe-In2S3-CdS device, and (iii) reduced recombination currents in both the QNR and SCR of the CZTSSe-CdS-In2S3 device. This accounts for a notable 9.0% average increase in the short-circuit current density (JSC) observed in CZTSSe-CdS-In2S3 in comparison to the CdS-only CZTSSe solar cells. Energy-dispersive X-ray, secondary-ion mass spectroscopy, and grazing-incidence X-ray diffraction compositional analysis of the CZTSSe layer in the three types of kesterite solar cells suggest that there is diffusion of elemental In and Cd into the absorbers with a hybrid buffer. Enhanced Cd diffusion concomitant with a double postdeposition heat treatment of the hybrid buffer layers in the CZTSSe-CdS-In2S3 device increases carrier collection and extraction and boosts JSC. This is evidenced by electron-beam-induced current measurements, where higher current generation and collection near to the p-n junction is observed, accounting for the increase in JSC in this device. It is expected that optimization of the heat treatment of the hybrid buffer layers will lead to further improvements in the device performance.

3.
Artigo em Chinês | MEDLINE | ID: mdl-37828881

RESUMO

Objective:By detecting the levels of proteins in the Toll-like receptor-4/nuclear factor-κB (TLR4/NF-κB) signaling pathway and downstream proinflammatory cytokines in peripheral blood of patients with Meniere's disease (MD), Pittsburgh Sleep Quality Index (PSQI) scores were collected to investigate the correlation between sleep disorders and MD and the role of TLR4/NF-κB signaling pathway in mediating sleep disorders inducing MD. Methods:Thirty-two MD patients and 20 family members of patients without middle ear and inner ear related diseases were selected. Basic data, PSQI and fasting peripheral blood of all subjects were collected. Enzyme linked immunosorbent assay.The levels of interleukin-1ß(IL-1ß), tumor necrosis factor-α(TNF-α), monocyte chemokine-1(MCP-1), Toll-like receptor 4(TLR4) and nuclear factor-κB(NF-κB) in peripheral blood were detected by ELISA, and the data were statistically analyzed. Results:①PSQI score of MD group was higher than that of normal control group, and the difference was statistically significant(P<0.01); The scores of every factors of PSQI in MD group were higher than those in normal control group, and the scores of factors 2, 4 and 6 were significantly different from those in normal control group. ②In the MD group, there were 18 patients with sleep disorders, with a prevalence rate of 56.25%, including 6 males with a prevalence rate of 50.00% and 12 females with a prevalence rate of 60.00%. ③The levels of five test indexes in MD group, sleep disorder group and non-sleep disorder group were higher than those in control group, and the levels of TLR4 and NF-κB in MD group were significantly different from those in control group(P<0.05). The levels of IL-1ß, TNF-α, TLR4 and NF-κB in sleep disorder group were significantly different from those in control group(P<0.05). The levels of five test indexes in non-sleep disorder group were not statistically significant compared with those in control group. The levels of five test indexes in the MD sleep disorder group were higher than those in the MD group and the non-sleep disorder group, with no statistical significance. The levels of five test indexes in MD group were higher than those in non-sleep disorder group, with no statistical significance(P>0.05). Conclusion:①Sleep disorders may be one of the important predisposing factors of some MD, and the effects of sleep disorders on MD are different between the sexes. ②Sleep disorders may activate TLR4/NF-κB signaling pathway to induce MD. The selection of TLR4/NF-κB signaling pathway related proteins and downstream pro-inflammatory factor inhibitors to intervene MD may provide a new idea for protecting the hearing balance function of MD.


Assuntos
Doença de Meniere , NF-kappa B , Receptor 4 Toll-Like , Feminino , Humanos , Masculino , NF-kappa B/metabolismo , Transdução de Sinais , Privação do Sono , Fator de Necrose Tumoral alfa/metabolismo
4.
Asian J Surg ; 46(11): 5035-5036, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37591758
6.
Front Chem ; 10: 954588, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36226119

RESUMO

Simple compound antimony selenide (Sb2Se3) is a promising emergent light absorber for photovoltaic applications benefiting from its outstanding photoelectric properties. Antimony selenide thin film solar cells however, are limited by low open circuit voltage due to carrier recombination at the metallic back contact interface. In this work, solar cell capacitance simulator (SCAPS) is used to interpret the effect of hole transport layers (HTL), i.e., transition metal oxides NiO and MoO x thin films on Sb2Se3 device characteristics. This reveals the critical role of NiO and MoO x in altering the energy band alignment and increasing device performance by the introduction of a high energy barrier to electrons at the rear absorber/metal interface. Close-space sublimation (CSS) and thermal evaporation (TE) techniques are applied to deposit Sb2Se3 layers in both substrate and superstrate thin film solar cells with NiO and MoO x HTLs incorporated into the device structure. The effect of the HTLs on Sb2Se3 crystallinity and solar cell performance is comprehensively studied. In superstrate device configuration, CSS-based Sb2Se3 solar cells with NiO HTL showed average improvements in open circuit voltage, short circuit current density and power conversion efficiency of 12%, 41%, and 42%, respectively, over the standard devices. Similarly, using a NiO HTL in TE-based Sb2Se3 devices improved open circuit voltage, short circuit current density and power conversion efficiency by 39%, 68%, and 92%, respectively.

7.
Faraday Discuss ; 239(0): 70-84, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-35822567

RESUMO

Cu2ZnSn(S,Se)4 (CZTSSe) is a promising material for thin-film photovoltaics, however, the open-circuit voltage (VOC) deficit of CZTSSe prevents the device performance from exceeding 13% conversion efficiency. CZTSSe is a heavily compensated material that is rich in point defects and prone to the formation of secondary phases. The landscape of these defects is complex and some mitigation is possible by employing non-stoichiometric conditions. Another route used to reduce the effects of undesirable defects is the doping and alloying of the material to suppress certain defects and improve crystallization, such as with germanium. The majority of works deposit Ge adjacent to a stacked metallic precursor deposited by physical vapour deposition before annealing in a selenium rich atmosphere. Here, we use an established hot-injection process to synthesise Cu2ZnSnS4 nanocrystals of a pre-determined composition, which are subsequently doped with Ge during selenisation to aid recrystallisation and reduce the effects of Sn species. Through Ge incorporation, we demonstrate structural changes with a negligible change in the energy bandgap but substantial increases in the crystallinity and grain morphology, which are associated with a Ge-Se growth mechanism, and gains in both the VOC and conversion efficiency. We use surface energy-filtered photoelectron emission microscopy (EF-PEEM) to map the surface work function terrains and show an improved electronic landscape, which we attribute to a reduction in the segregation of low local effective work function (LEWF) Sn(II) chalcogenide phases.

8.
Front Chem ; 10: 920676, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35844645

RESUMO

Developing effective device architectures for energy technologies-such as solar cells, rechargeable batteries or fuel cells-does not only depend on the performance of a single material, but on the performance of multiple materials working together. A key part of this is understanding the behaviour at the interfaces between these materials. In the context of a solar cell, efficient charge transport across the interface is a pre-requisite for devices with high conversion efficiencies. There are several methods that can be used to simulate interfaces, each with an in-built set of approximations, limitations and length-scales. These methods range from those that consider only composition (e.g. data-driven approaches) to continuum device models (e.g. drift-diffusion models using the Poisson equation) and ab-initio atomistic models (developed using e.g. density functional theory). Here we present an introduction to interface models at various levels of theory, highlighting the capabilities and limitations of each. In addition, we discuss several of the various physical and chemical processes at a heterojunction interface, highlighting the complex nature of the problem and the challenges it presents for theory and simulation.

9.
ACS Appl Energy Mater ; 5(5): 5404-5414, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35647491

RESUMO

For successful long-term deployment and operation of kesterites Cu2ZnSn(S x Se1-x )4 (CZTSSe) as light-absorber materials for photovoltaics, device stability and recovery in kesterite solar cells are investigated. A low-temperature heat treatment is applied to overcome the poor charge extraction that developed in the natural aging process. It is suggested that defect states at aged CZTSSe/CdS heterojunctions were reduced, while apparent doping density in the CZTSSe absorber increased due to Cd/Zn interdiffusion at the heterojunction during the annealing process. In situ annealing experiments in a transmission electron microscope were used to investigate the elemental diffusion at the CZTSSe/CdS heterojunction. This study reveals the critical role of heat treatment to enhance the absorber/Mo back contact, improve the quality of the absorber/buffer heterojunction, and recover the device performance in aged kesterite thin-film solar cells.

10.
Artigo em Chinês | MEDLINE | ID: mdl-35193336

RESUMO

Objective:To analyze the coagulation status and prognosis of sudden deafness patients with total deafness accompanied by vertigo, and to provide basis for improving the treatment of this disease. Methods:From January 2017 to December 2020, 33 patients with total deafness and vertigo sudden deafness who were hospitalized in the Department of Otolaryngology Head and Neck Surgery, Hebei Provincial People's Hospital were selected as the research group. During the same period, 33 cases of low frequency type, full frequency type, total deafness and 26 cases of high frequency type were treated as control group.Thirty-three cases of inpatients without history of middle ear and inner ear diseases were treated as normal control group. The levels of fibrinogen(FIB), D-Dimer(D-D), Prothrombin Time(PT), Activated Partial Thrombin Time(APTT) between the research group and the control group were analyzed, and the therapeutic effects of different types of sudden deafness patients were analyzed. Results:FIB and D-D of total deafness with vertigo were 2.50(2.11, 2.95)and 0.27(0.16, 0.51) respectively, which were higher than 2.31(1.92, 2.50) and 0.17(0.12, 0.21) of normal group. APTT was 25.2(23.1, 28.1), lower than 27.3(26.4, 29.7) in the normal group, the differences were statistically significant(P<0.01). ② FIB of total deafness with vertigo was 2.50(2.11, 2.95), which was higher than that of low frequency group 2.37(1.81, 2.68). D-D was 0.27(0.16, 0.51), higher than low frequency group 0.16(0.12, 0.25), high frequency group of 0.13(0.11, 0.23), the whole frequency group 0.16(0.11, 0.28), total of 0.18(1.45, 0.30). APTT was 25.75±3.18/25.2(23.1, 28.1), lower than 27.72±2.22 in low frequency group and 26.7(25.8, 28.7) in full frequency group, with statistical significance(P<0.05). ③ The total deafness with vertigo group had the worst curative effect(ineffective rate was 63.6%), and the low frequency group had the best curative effect(recovery rate was 75.8%). The difference of curative effect among different types of sudden deafness groups was statistically significant(P<0.05). Conclusion:Hypercoagulability and thrombosis may be one of the influencing factors of total sudden deafness. The hypercoagulable state of sudden deafness patients with total deafness and vertigo is more serious than that of total deafness and other types of sudden deafness, and the prognosis is the worst.


Assuntos
Testes de Coagulação Sanguínea , Surdez , Perda Auditiva Súbita , Vertigem , Surdez/complicações , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Fibrinogênio/análise , Perda Auditiva Súbita/complicações , Perda Auditiva Súbita/terapia , Humanos , Prognóstico , Vertigem/complicações
11.
ACS Appl Mater Interfaces ; 11(18): 16567-16570, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30983317

RESUMO

Multifunctional fullerene microcrystals have been prepared by the involvement of water in the liquid-liquid interfacial precipitation. The resulting microcrystals were characterized microscopically and spectroscopically. The role of water in engineering charge-transfer interactions between fullerenes and electron-donating solvents has been corroborated through thermogravimetric and transient absorption spectroscopy analyses.

12.
RSC Adv ; 8(7): 3470-3476, 2018 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-35542929

RESUMO

Earth abundant Cu2ZnSnS4 nanoparticle inks were deposited on molybdenum foil substrates and subsequently converted to high quality thin film Cu2ZnSn(S,Se)4 photovoltaic absorbers. Integration of these absorbers within a thin film solar cell device structure yields a solar energy conversion efficiency which is comparable to identical devices processed on rigid glass substrates. Importantly, this is only achieved when a thin layer of molybdenum is first applied directly to the foil. The layer limits the formation of a thick Mo(S,Se) x layer resulting in a substantially reduced series resistance.

13.
Artigo em Chinês | MEDLINE | ID: mdl-26121830

RESUMO

OBJECTIVE: To explore the treatment of sudden sensorineural hearing loss with steroid from different administration routes. METHOD: One hundred and eighty-eight patients with diagnosis of sudden sensorineural hearing loss were selected, in accordance with the random number table, and all patients were divided into three groups. With different administration routes, they were devided into systemic steroid therapy group, intratympanic steroid therapy group and postauricular steroid therapy group,and the curative effects were collected and analyzed. RESULT: The total effective rate was 78.26% in systemic steroid therapy group, 80.70% in intratympanic steroid therapy group and 80.65% in postauricularsteroid therapy group,and no statistical difference was detected among these three groups (P > 0.05). CONCLUSION: The treatment of sudden sensorineural hearing loss with steroid from different adminsthation routes all can achieve a relatively favorable prognosis, and there were no obvious different among those different treatments.


Assuntos
Dexametasona/administração & dosagem , Glucocorticoides/administração & dosagem , Perda Auditiva Súbita/tratamento farmacológico , Administração Oral , Audiometria de Tons Puros , Perda Auditiva Neurossensorial , Humanos , Prognóstico , Esteroides , Resultado do Tratamento , Membrana Timpânica
14.
Int J Oncol ; 43(1): 131-40, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23652853

RESUMO

Hypoxia promotes the radioresistance of laryngeal carcinomas and CD133 is one of the markers expressed by tumor-initiating, human laryngeal carcinoma cells. In order to investigate whether CD133-positive Hep-2 cells exhibit a radioresistant phenotype and to determine whether hypoxia promotes this phenotype, we performed a series of experiments. Hep-2 cells, and Hep-2 cells stably expressing hypoxia-inducible factor (HIF)-targeted small interfering RNA (siRNA) were cultured under hypoxic and normoxic conditions and were treated with varying doses of γ-rays (0, 5, 10, 15 and 20 Gy). MTT and cell cycle assays were subsequently performed. Using fluorescence-activated cell sorting (FACS), CD133-positive Hep-2 cells and CD133-positive HIF-siRNA Hep-2 cells were isolated. These cells were grown as spheres under hypoxic and normoxic conditions for MTT and soft agar colony formation assays. The expression levels of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), survivin, p53 and ataxia-telangiectasia mutated (ATM) were also assayed using flow cytometry. The data showed that the growth of Hep-2 cells exposed to hypoxic conditions and treated with 10 Gy radiation (group A) was less compared to that of groups B-D (P<0.05). In addition, more cells in group A were arrested in the G1 phase of the cell cycle compared to groups B-D (P<0.05). The percentage of CD133+ cells detected after radiation increased and was the highest for group A (P<0.05). In sphere formation assays, significantly more CD133+ cells grew in spheres than CD133- cells (P<0.001). Moreover, sphere formation was the highest for CD133+ Hep-2 cells grown under hypoxic conditions and exposed to irradiation (group E) (P<0.05). Lastly, expression of DNA-PKcs and survivin for group E was the highest (P<0.05), while ATM and p53 levels remained largely unchanged (P>0.05). In conclusion, CD133-positive Hep-2 cells exhibited a radioresistant phenotype that was enhanced with hypoxia. Furthermore, an increase in DNA-PK activity was associated with this enhancement.


Assuntos
Antígenos CD/genética , Carcinoma de Células Escamosas/patologia , Glicoproteínas/genética , Neoplasias Laríngeas/patologia , Neoplasias Laríngeas/radioterapia , Peptídeos/genética , Tolerância a Radiação/genética , Antígeno AC133 , Antígenos CD/metabolismo , Apoptose/efeitos da radiação , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/radioterapia , Hipóxia Celular/efeitos da radiação , Linhagem Celular Tumoral , Citometria de Fluxo , Raios gama , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Glicoproteínas/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Laríngeas/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/efeitos da radiação , Peptídeos/metabolismo , RNA Interferente Pequeno/genética
15.
Mol Med Rep ; 6(6): 1418-22, 2012 12.
Artigo em Inglês | MEDLINE | ID: mdl-22971798

RESUMO

The present study evaluated the regulation of glucose transporter protein-1 (Glut-1) and vascular endothelial growth factor (VEGF) by hypoxia inducible factor 1α (HIF-1α) under hypoxic conditions in Hep-2 human cells to explore the feasibility of these three genes as tumor markers. Hep-2 cells were cultured under hypoxic and normoxic conditions for 6, 12, 24, 36 and 48 h. The proliferation of Hep-2 cells was evaluated using an MTT assay. The protein and mRNA expression levels of HIF-1α, Glut-1 and VEGF were detected using the S-P immunocytochemical method, western blotting and reverse transcription polymerase chain reaction (RT-PCR). The results revealed that the expression levels of HIF-1α, Glut-1 and VEGF protein in Hep-2 cells were significantly elevated under hypoxic conditions compared with those under normoxic conditions over 36 h. Under hypoxic conditions, mRNA levels of HIF-1α were stable, while mRNA levels of Glut-1 and VEGF changed over time. In conclusion, Glut-1 and VEGF were upregulated by HIF-1α under hypoxic conditions in a time-dependent manner in Hep-2 cells and their co-expression serves as a tumor marker.


Assuntos
Hipóxia Celular , Transportador de Glucose Tipo 1/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Linhagem Celular Tumoral , Transportador de Glucose Tipo 1/genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Imuno-Histoquímica , RNA Mensageiro/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/genética
16.
Artigo em Chinês | MEDLINE | ID: mdl-22805025

RESUMO

OBJECTIVE: To investigate the effects of hypoxia on the features and chemoresistance of cancer stem cells in Hep-2 cells and underlying mechanism. METHODS: The shRNA interference recombinant plasmid targeting HIF-1α was synthesized and transfected into Hep-2 cells. The HIF-1α knockdown Hep-2 cells were established after clonal selection and the expression of HIF-1α was measured. The cellular features including proliferation, clonal formation, cell cycle, apoptosis and CD133 phenotype were measured in Hep-2 cells cultured under hypoxic condition in vitro. CD133+ cells were sorted from Hep-2 cells with flow cytometry. Clonal formation test and cisplatin treatment were carried out, and the expressions of related genes (Oct-4, suvivin and p53) in CD133+ cells were measured. RESULTS: HIF-1α knockdown Hep-2 cells was successfully established, as evidenced by the reduced mRNA and protein expressions of HIF-1α. The Hep-2 cells cultured under hypoxic microenvironment showed higher proliferation and clonal formation activity, cell cycle arrest in G0/G1, lower apoptosis, up-regulated CD133, however the effects of hypoxia reduced in HIF-1α knockdown Hep-2 cells. CD133+ cells were successfully sorted from Hep-2 cells, and the CD133+ cells showed increased clonal formation activity and cisplatin treatment resistance in hypoxia. Also the effects of hypoxia on CD133+ cells decreased with HIF-1α knockdown, showing down-regulated Oct-4 and survivin and up-regulated p53. CONCLUSIONS: Hypoixa can induce the features of cancer stem cells in Hep-2 cells and increase proliferation, differentiation and chemoresistant ability of CD133+ cells, which might be correlated with the changes in expressions of HIF-1α and related genes regulated by HIF-1α.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Células-Tronco Neoplásicas/citologia , Apoptose , Carcinoma de Células Escamosas/patologia , Ciclo Celular , Diferenciação Celular , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Laríngeas/patologia , RNA Interferente Pequeno/genética
17.
Artigo em Chinês | MEDLINE | ID: mdl-22800355

RESUMO

OBJECTIVE: To detect the expression of hypoxia inducible factor 1 alpha (HIF-1α), glucose transporter protein-1 (GLUT-1) and vascular endothelial growth factor (VEGF) in human laryngeal carcinoma tissue, and to study the relationship between hypoxia and HIF-1α, GLUT-1, VEGF in human laryngeal carcinoma Hep-2 cells and to explore the effect of HIF-1α, GLUT-1 and VEGF as endogenous hypoxic markers on laryngeal carcinoma. METHODS: The expression levels of HIF-1α, GLUT-1 and VEGF were detected in 35 cases of laryngeal carcinoma by SP immunohistochemical methods and in Hep-2 cells by SP immunocytochemical methods. The relationship between HIF-1α and GLUT-1, VEGF protein expression was analyzed. RESULTS: Of the 35 cases, 16 cases expressed HIF-1α, 16 cases expressed GLUT-1, 19 cases expressed VEGF. The expression of HIF-1α and VEGF were closely correlated with pathologic grading and lymphnode metastasis. GLUT-1 was correlated with lymphnode metastasis. The expression levels of HIF-1α, GLUT-1 and VEGF in Hep-2 cells under hypoxic condition were higher than those under normoxic condition. CONCLUSION: HIF-1α may promote the expression of GLUT-1 and VEGF in laryngeal carcinoma, furthermore promote tumor angiogenesis, invasion, and metastasis of the laryngeal carcinoma.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Laríngeas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Feminino , Transportador de Glucose Tipo 1/metabolismo , Humanos , Neoplasias Laríngeas/patologia , Masculino , Pessoa de Meia-Idade , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
Artigo em Chinês | MEDLINE | ID: mdl-22336015

RESUMO

OBJECTIVE: To study whether laryngeal cancer stem cells in hypoxia have the characteristic of resistance to irradiation and underlying mechanism. METHODS: CD133(+) cells were separated from Hep-2 cells with flow cytometry (FCM) and the purity was 92.8%. The separated CD133(+) cells were cultured in serum-free medium in hypoxia in normoxia environment respectively, and hypoxia-inducible factor 1 alpha (HIF-1α) expression was detected by FCM. The cells were exposed respectively to X-rays emitted by linear accelerator with a dose of 0, 5, 10, 15 or 20 Gy for 24 hours, with additional time points of 12, 36, and 48 hours for the cells exposed to 10 Gy. Then the growth inhibition ratios of cells in hypoxia and normoxia groups were detected with MTT assay at different time points. Soft agar colony formation assay was used to detect colony formation ratios of cells in hypoxia and normoxia groups. DNA dependent protein kinase catalytic subunit (DNA-PKcs), ataxia telangiectasia mutate (ATM), Survivin and P53 were detected by FCM. RESULTS: Growth inhibition ratio of CD133(+) cells in hypoxia group was lower than that in normoxia group (P < 0.05). Colony formation ratio of CD133(+) cells was higher than that of CD133(-) cells (P < 0.01) and the ratio of CD133(+) cells in hypoxia group was higher than that in normoxia group (P < 0.05). The ratio of hypoxia group was not affected by irradiation, while the ratio of normoxia group decreased significantly after irradiation (P < 0.05). The expressions of DNA-PKcs, ATM, Survivin and P53 in CD133(+) cells were higher than those in CD133(-) cells respectively (P < 0.01). In CD133(+) cells with radiation, the expressions of DNA-PKcs and Survivin of hypoxia group were higher those of normoxia group (P < 0.05), but no difference in the expression of ATM or P53 between the two groups. CONCLUSIONS: Laryngeal cancer stem cells play an important role in radioresistance mediated by hypoxia.


Assuntos
Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/radioterapia , Células-Tronco Neoplásicas/metabolismo , Oxigênio/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo
19.
Artigo em Chinês | MEDLINE | ID: mdl-22256736

RESUMO

OBJECTIVE: To study whether cancer stem cells promotes resistance of laryngeal squamous cancer to irradiation mediated by hypoxia. METHOD: Hep-2 cells were respectively cultured in hypoxia and normoxia environment, and the express of HIF-la was detected by western blot. Then they were radiated with different doses of gamma-rays. After that we detected growth inhibition ratio with MTT assay, cell circle and ratio of CD133+ cells with Flow cytometry at different times. RESULT: MTT assay showed that inhibition ratio of the hypoxia group was lower than that of the normoxia group after different doses of gamma-rays at each time point, and the difference was significant 24 h after 10 Gy irradiation (P < 0.05). The results of Flow cytometry demonstrated that cells of the two groups were arrested at G1 phase, and cells ratio in G1 phase of the hypoxia group was higher than that of he normoxia group after 10 Gy irradiation. The ratio of CD133-positive cells was higher in the hypoxia group than in the normoxia group after radiation, and difference was significant 24 h after 10 Gy irradiation (P < 0.05). In each group, the ratio of CD133-positive cells became higher after radiation than that before radiation (P < 0. 05). CONCLUSION: We can conclude that cancer stem cells play an important role in radioresistance mediated by hypoxia.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Laríngeas/radioterapia , Células-Tronco Neoplásicas/citologia , Tolerância a Radiação , Hipóxia Celular , Linhagem Celular Tumoral , Raios gama , Humanos
20.
Artigo em Chinês | MEDLINE | ID: mdl-19266815

RESUMO

OBJECTIVE: To observe the short-term efficacy of autogenous bone pate and Palva graft for obliterating huge remnant mastoid cavity in canal wall down approach. METHOD: Retrospective analysis clinical data of twenty-one cholesteatomatous cases operated by one surgeon from 2004 to 2007. In twelve cases, simultaneous III type tympanoplasty (Sheehy, P. O. P) was performed. Other 9 cases had undergone mastoidectomy elsewhere before the admission. Six of them were still draining with huge remnant mastoid cavity, and the rest three patients had relapsed cholesteatomas with intermittent draining and huge mastoid cavity. Normal saline solution perfusion was used to measure the volume of remnant mastoid cavity. The criterion of huge remnant mastoid cavity is more than 8 ml. RESULT: Of twelve primary cases with III type tympanoplasty, 11 patients maintained a small, dry, and healthy mastoid cavity after twenty-seven days. The average increase of hearing level of them was 17.5dB, and the air-bone gap is less than 20 dB. Of one patient, bone pate was infected and was discharged. A dry mastoid cavity was achieved until fifty-five days after surgery. The patient is keeping a big air-bone gap caused by displacement of ossicle chain prosthesis. Just eighteen days later, other nine cases of revision mastoidectomy achieved a small, dry, and healthy mastoid cavity, with lightly improved hearing level. CONCLUSION: Obliteration of a canal wall down huge mastoid cavity by Palva graft with autologous bone pate is a reliable and effective technique that results in a small, dry, low-maintenance mastoid cavity. The short-term efficacy of simultaneous III tympanoplasty is satisfactory if patient selection is suitable.


Assuntos
Colesteatoma/cirurgia , Processo Mastoide/cirurgia , Adolescente , Adulto , Colesteatoma da Orelha Média/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Retalhos Cirúrgicos , Transplante Autólogo , Resultado do Tratamento , Timpanoplastia/métodos , Adulto Jovem
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