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2.
Biophys J ; 118(5): 1196-1204, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32023438

RESUMO

Intercellular bridges are plasma continuities formed at the end of the cytokinesis process that facilitate intercellular mass transport between the two daughter cells. However, it remains largely unknown how the intercellular bridge mediates Ca2+ communication between postmitotic cells. In this work, we utilize BV-2 microglial cells planted on dumbbell-shaped micropatterned assemblies to resolve spatiotemporal characteristics of Ca2+ signal transfer over the intercellular bridges. With the use of such micropatterns, considerably longer and more regular intercellular bridges can be obtained than in conventional cell cultures. The initial Ca2+ signal is evoked by mechanical stimulation of one of the daughter cells. A considerable time delay is observed between the arrivals of passive Ca2+ diffusion and endogenous Ca2+ response in the intercellular-bridge-connected cell, indicating two different pathways of the Ca2+ communication. Extracellular Ca2+ and the paracrine pathway have practically no effect on the endogenous Ca2+ response, demonstrated by application of Ca2+-free medium, exogenous ATP, and P2Y13 receptor antagonist. In contrast, the endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin and inositol trisphosphate (IP3) receptor blocker 2-aminoethyl diphenylborate significantly inhibit the endogenous Ca2+ increase, which signifies involvement of IP3-sensitive calcium store release. Notably, passive Ca2+ diffusion into the connected cell can clearly be detected when IP3-sensitive calcium store release is abolished by 2-aminoethyl diphenylborate. Those observations prove that both passive Ca2+ diffusion and IP3-mediated endogenous Ca2+ response contribute to the Ca2+ increase in intercellular-bridge-connected cells. Moreover, a simulation model agreed well with the experimental observations.

3.
Environ Pollut ; 260: 113973, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31991351

RESUMO

Both agricultural and construction machinery are important non-road sources of atmospheric pollution, with total hydrocarbons (THC), nitrogen oxides (NOx) and particulate matter (PM) emissions accounting for more than 60% of the total emissions from all non-road mobile sources in China. However, there exist relatively few efforts to establish the emission inventory for these machineries. This study attempted to estimate and predict air pollutant emissions from agricultural and construction diesel machinery, using the Beijing-Tianjin-Hebei (BTH) region as the case study area. The results show that total emissions of PM10, PM2.5, THC, NOX, CO and SO2 in 2015 were 41.10, 38.80, 86.14, 520.41, 379.01 and 17.32 Kt respectively. The contribution of agricultural machinery was slightly higher than that of construction machinery, accounting for 60-71% of the total. Moreover, emissions of various pollutants (except SO2) from agricultural machinery were mainly distributed in central Hebei (Cangzhou, Shijiazhuang and Baoding), while emissions from construction machinery were mainly distributed in Beijing and Tianjin. The prediction suggest that the total emissions of agricultural and construction diesel machinery in the BTH region would increase by 6% in 2020 and 9% in 2025. Moreover, pollutant emissions from construction machinery would contribute from 29% to 40% in 2015 to 34%-61% in 2025. These results could provide important information for making effective mitigation measures of non-road mobile sources.

4.
Environ Pollut ; 259: 113863, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31918139

RESUMO

Large ammonia (NH3) emissions contribute approximately 8-30% to the fine particle pollution in China and highlight the need for understanding the emission trends and mitigation effects of NH3 in the future. The purpose of this study is to predict the NH3 emissions and analyze the mitigation potential up to year 2040 by scenario analysis based on the established new NH3 emission inventory from anthropogenic sources for the Beijing-Tianjin-Hebei (BTH) region. The results showed that the total NH3 emission in the BTH region was estimated at 966.14 Gg in 2016. Under the Business-as-Usual (BAU) scenario, the total NH3 emissions in 2030 and 2040 would increase by 13% and 26% compared with 2016 levels, with average annual growth rates of 0.9% and 1.0%, respectively. Livestock will continue to dominate NH3 emissions in the future, with the proportions of total emissions increasing from 57% in 2016 to 64% in 2030 and 68% in 2040. The share of the second-largest NH3 emission source, synthetic fertilizer application, will decrease from 36% in 2016 to 31% in 2030 and 27% in 2040. Among five other sources, the largest change occurred in waste disposal, increasing notably by 3.31 times from 2016 to 2040 owing to rapid urbanization. Under the Combined Options (CO) scenario, the total NH3 emissions could be reduced by as much as 34% by 2030 and 50% by 2040 compared with the BAU scenario, which is attributed to livestock (24% in 2030, 37% in 2040) and synthetic fertilizer application (10% in 2030, 13% in 2040), respectively. This study can give a reliable estimation of anthropogenic NH3 emission in the BTH region during 2020-2040 and provide a valuable reference for effective mitigation measures and control strategies for policy makers.


Assuntos
Poluentes Atmosféricos , Amônia , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Amônia/análise , Animais , China , Conservação dos Recursos Naturais , Gado
5.
Opt Express ; 27(26): 38159-38167, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31878587

RESUMO

Molecular-like silver nanoclusters (ML-Ag NCs) with size dependent tunable luminescence properties and high-quantum yield has been explored as a new type of sensitizer for rare earth (RE) ions in glasses recently. In this research, the borosilicate glasses containing ML-Ag NCs and RE3+ (RE = Sm, Eu, Tb) ions were prepared with melt-quenching method. The absorption, TEM and steady spectra measurements indicated that compare with Sm3+ and Tb3+, the introduction of Eu3+ can more effectively promote the formation of luminescent ML-Ag NCs and their further aggregation. Besides the predictable efficient energy transfer from ML-Ag NCs to a single type of RE3+ ion in the codoped glasses, the simultaneously sensitization of Sm3+/Eu3+ and Sm3+/Tb3+ couples by ML-Ag NCs were further realized in the tri-doped glasses. Benefited from the excitation wavelength dependence of energy transfer from ML-Ag NCs to Sm3+/Eu3+ and Sm3+/Tb3+ couples and excitation efficiency on ML-Ag NCs and RE3+ ions, the tri-doped glasses exhibit broad tunable emission simply by changing the excitation wavelength, and the white light emission was achieved in GAgSmEu under UV excitation.

6.
Biosci Rep ; 39(6)2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138762

RESUMO

Traditional Chinese Medicine (TCM) has been recognized to be conducive to enhancing the efficiency and reducing the side effects in the whole course of cancer treatment. The mechanisms of TCM/chemotherapy combination involved with interleukin-7 (IL-7) potentially enhance immune responses against tumor. In the present study, we emphasized on a herbal formulation Yi-qi-yang-yin-tian-sui-fang or TCM for short, and investigated its roles in chemotherapy in non-small cell lung cancer (NSCLC). The mice bared with tumor were treated with cisplatin (DDP) and simultaneously administrated with/without low, medium and high doses of TCMs (effective content: 0.5, 2.0 and 8.0 g/per mice) via oral gavage. The results indicated that combination of TCM further elevated the therapy efficiency of DDP in a dose-dependent manner. The growth of tumor cells was estimated by Ki-67 stain and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay. The addition of TCM to the DDP treatment could significantly decrease the expression of Ki-67 and promote the apoptosis of tumor cells. In addition, the serum IL-7 level was down-regulated by DDP but restored by the treatment of TCM. The expression of IL-7 and its receptor IL-7R in tumor tissues was also recovered by TCM. Furthermore, the side effect from bone marrow suppression (myelosuppression) induced by DDP were assessed. TCM could abrogate DDP-induced apoptosis of bone marrow and also remarkably induced the expressions of IL-7 and hematopoietic growth factors including G-CSF, GM-CSF, SCF, and SDF-1 in bone marrow. These data indicated that this TCM combined with DDP showed superior anti-tumor effects with reduced myelosuppression via up-regulating IL-7.

7.
ACS Appl Mater Interfaces ; 11(13): 12656-12665, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30844227

RESUMO

Understanding the piezoelectricity mechanism is crucial for developing new materials for better performance. Here, we developed a nanogenerator based on the ZnO thin films having various TC(002) values. The output current well correlated to the magnitude of (002) texture coefficient (TC(002)). Additionally, the TC(002)-dependent photovoltaic and rectification properties are observed. When the film is subjected to persistent compression, the photovoltaic, rectification, and piezoelectric properties fade away. Based on our observation that the ZnO polar structure always shows a spontaneous electron field (SEF), we thus propose a new piezoelectricity mechanism. The [001]-orientated ZnO thin film with the SEF is equivalent to a capacitor, the compression functions as a discharging process, and the removal of the external stress serves as a charging process. The physical mechanism provides an insight into various energy conversion processes that will inspire advanced designs of high-performance nanogenerators, solar cells, and other optoelectronic devices.

8.
Plant Biotechnol J ; 17(4): 762-775, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30220108

RESUMO

Upland cotton (Gossypium hirsutum) is the world's largest source of natural fibre and dominates the global textile industry. Hybrid cotton varieties exhibit strong heterosis that confers high fibre yields, yet the genome-wide effects of artificial selection that have influenced Upland cotton during its breeding history are poorly understood. Here, we resequenced Upland cotton genomes and constructed a variation map of an intact breeding pedigree comprising seven elite and 19 backbone parents. Compared to wild accessions, the 26 pedigree accessions underwent strong artificial selection during domestication that has resulted in reduced genetic diversity but stronger linkage disequilibrium and higher extents of selective sweeps. In contrast to the backbone parents, the elite parents have acquired significantly improved agronomic traits, with an especially pronounced increase in the lint percentage. Notably, identify by descent (IBD) tracking revealed that the elite parents inherited abundant beneficial trait segments and loci from the backbone parents and our combined analyses led to the identification of a core genomic segment which was inherited in the elite lines from the parents Zhong 7263 and Ejing 1 and that was strongly associated with lint percentage. Additionally, SNP correlation analysis of this core segment showed that a non-synonymous SNP (A-to-G) site in a gene encoding the cell wall-associated receptor-like kinase 3 (GhWAKL3) protein was highly correlated with increased lint percentage. Our results substantially increase the valuable genomics resources available for future genetic and functional genomics studies of cotton and reveal insights that will facilitate yield increases in the molecular breeding of cotton.


Assuntos
Genoma de Planta/genética , Genômica , Gossypium/genética , Produtos Agrícolas , Domesticação , Loci Gênicos , Genótipo , Desequilíbrio de Ligação , Linhagem , Fenótipo , Melhoramento Vegetal
9.
Mediators Inflamm ; 2019: 7241418, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31915416

RESUMO

Treatment with cisplatin (DDP) is one of the standard therapies used to treat non-small-cell lung cancer (NSCLC) and fundamentally causes resistance in cancer cells, which eventually poses as an obstacle to the efficacy of chemotherapy in NSCLC. Efforts are on all over the world to explore a sensitizer of NSCLC to DDP. Here, we studied the effect of IL-7 on the resistance of NSCLC to chemotherapy. We observed that IL-7 treatment significantly enhanced DDP-induced effects in A549 and A549/DDP cells (DDP-resistant cells), including decreased cell viability and proliferation, as well as increased cell apoptosis and S arrest, indicating that IL-7 treatment resensitized DDP-resistant NSCLC cells to DDP. Subsequently, IL-7 enhanced the sensitivity of PI3K/AKT signaling and expressions of ABCG2 to DDP. By inhibiting IL-7 signaling via IL-7R knockdown or activating PI3K/AKT signaling via PI3K activation, the resensitization to DDP by IL-7 was abrogated, and the expression levels of ABCG2, p-PI3K, and p-AKT were found to be significantly higher. In vivo results also confirmed that IL-7 only in combination with DDP could remarkably induce tumor regression with reduced levels of ABCG2 in tumorous tissues. These findings indicate that IL-7, apart from its adjuvant effect, could overcome multidrug resistance of DDP to restore its chemotherapy sensitivity.

10.
Ecol Evol ; 8(21): 10587-10593, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30464830

RESUMO

Aim: DNA barcoding has been widely applied to species diversity assessment in various ecosystems, including temperate forests, subtropical forests, and tropical rain forests. However, tropical coral islands have never been barcoded before due to the difficulties in field exploring. This study aims at barcoding the flowering plants from a unique ecosystem of the tropical coral islands in the Pacific Ocean and supplying valuable evolutionary information for better understanding plant community assembly of those particular islands in the future. Location: Xisha Islands, China. Methods: This study built a DNA barcode database for 155 plant species from the Xisha Islands using three DNA markers (ITS, rbcL, and matK). We applied the sequence similarity method and a phylogenetic-based method to assess the barcoding resolution. Results: All the three DNA barcodes showed high levels of PCR success (96%-99%) and sequencing success (98%-100%). ITS performed the highest rate of species resolution (>95%) among the three markers, while plastid markers delivered a relatively poor species resolution (85%-90%). Our analyses obtained a marginal increase in species resolution when combining the three DNA barcodes. Main conclusions: This study provides the first plant DNA barcode data for the unique ecosystem of tropical coral islands and considerably supplements the DNA barcode library for the flowering plants on the oceanic islands. Based on the PCR and sequencing success rates, and the discriminatory power of the three DNA regions, we recommend ITS as the most successful DNA barcode to identify the flowering plants from Xisha Islands. Due to its high sequence variation and low fungal contamination, ITS could be a preferable candidate of DNA barcode for plants from other tropical coral islands as well. Our results also shed lights on the importance of biodiversity conservation of tropical coral islands.

11.
Nanomicro Lett ; 10(4): 71, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30393719

RESUMO

Nitrogen-doped TiO2-C composite nanofibers (TiO2/N-C NFs) were manufactured by a convenient and green electrospinning technique in which urea acted as both the nitrogen source and a pore-forming agent. The TiO2/N-C NFs exhibit a large specific surface area (213.04 m2 g-1) and a suitable nitrogen content (5.37 wt%). The large specific surface area can increase the contribution of the extrinsic pseudocapacitance, which greatly enhances the rate capability. Further, the diffusion coefficient of sodium ions (D Na+) could be greatly improved by the incorporation of nitrogen atoms. Thus, the TiO2/N-C NFs display excellent electrochemical properties in Na-ion batteries. A TiO2/N-C NF anode delivers a high reversible discharge capacity of 265.8 mAh g-1 at 0.05 A g-1 and an outstanding long cycling performance even at a high current density (118.1 mAh g-1) with almost no capacity decay at 5 A g-1 over 2000 cycles. Therefore, this work sheds light on the application of TiO2-based materials in sodium-ion batteries.

12.
Artigo em Inglês | MEDLINE | ID: mdl-29660683

RESUMO

Tb3+-doped YAlO3 (YAP) single crystal was grown by Czochralski (Cz) method. Based on the polarized absorption spectra, the spectroscopic parameters were calculated to be Ω2=3.49×10-20cm2, Ω4=5.87×10-20cm2 and Ω6=2.55×10-20cm2, and then the spontaneous transition rate, fluorescent branching ratio and radiative lifetime of 5D4 multiplet were obtained. The yellow emission cross sections of 5D4→7F4 transition were calculated to be 1.72×10-22cm2, 2.73×10-22cm2 and 2.65×10-22cm2 for a, b and c polarization, respectively. The fluorescence lifetime of the 5D4 multiplet was fitted to be 1.72ms. All the data indicate that Tb:YAP crystal is a promising candidate for yellow laser operation.

13.
Plant Mol Biol ; 96(4-5): 403-416, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29383477

RESUMO

KEY MESSAGE: Based on the physiological and RNA-seq analysis, some progress has been made in elucidating the Cf-10-mediated resistance responses to C. fulvum infection in tomato. GO and KEGG enrichment analysis revealed that the DEGs were significantly associated with defense-signaling pathways like oxidation-reduction processes, oxidoreductase activity and plant hormone signal transduction. Leaf mold, caused by the fungus Cladosporium fulvum, is one of the most common diseases affecting tomatoes worldwide. Cf series genes including Cf-2, Cf-4, Cf-5, Cf-9 and Cf-10 play very important roles in resisting tomato leaf mold. Understanding the molecular mechanism of Cf gene-mediated resistance is thus the key to facilitating genetic engineering of resistance to C. fulvum infection. Progress has been made in elucidating two Cf genes, Cf -19 and Cf -12, and how they mediate resistance responses to C. fulvum infection in tomato. However, the mechanism of the Cf-10- mediated resistance response is still unclear. In the present study, RNA-seq was used to analyze changes in the transcriptome at different stages of C. fulvum infection. A total of 2,242 differentially expressed genes (DEGs) responsive to C. fulvum between 0 and 16 days post infection (dpi) were identified, including 1,501 upregulated and 741 downregulated genes. The majority of DEGs were associated with defense-signaling pathways including oxidation-reduction processes, oxidoreductase activity and plant hormone signal transduction. Four DEGs associated with plant-pathogen interaction were uniquely activated in Cf-10 tomato and validated by qRT-PCR. In addition, physiological indicators including reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were measured at 0-21 dpi, and hormone expression [Jasmonic acid (JA) and salicylic acid (SA)] was estimated at 0 and 16 dpi to elucidate the mechanism of the Cf-10-mediated resistance response. C. fulvum infection induced the activities of POD, CAT and SOD, and decreased ROS levels. JA was determined to participate in the resistance response to C. fulvum during the initial infection period. The results of this study provide accountable evidence for the physiological and transcriptional regulation of the Cf-10-mediated resistance response to C. fulvum infection, facilitating further understanding of the molecular mechanism of Cf-10-mediated resistance to C. fulvum infection.


Assuntos
Cladosporium/fisiologia , Resistência à Doença/genética , Genes de Plantas , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/fisiologia , Doenças das Plantas/imunologia , Análise de Sequência de RNA , Cladosporium/efeitos dos fármacos , Cladosporium/patogenicidade , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/imunologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/imunologia , Redes e Vias Metabólicas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/farmacologia , Folhas de Planta/citologia , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
14.
Onco Targets Ther ; 10: 4261-4267, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28894381

RESUMO

BACKGROUND: Several clinical studies have demonstrated that continuous administration of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) could provide additional survival benefit for advanced non-small cell lung cancer (NSCLC) patients who had benefited from prior EGFR TKI therapy. However, whether EGFR TKI combined with chemotherapy could further prolong survival in patients with gradual progression is still unclear. The present study was conducted to evaluate the clinical outcome of continuous EGFR TKI treatment in combination with chemotherapy (combination group) versus continuous EGFR TKI treatment only (monotherapy group) in such a clinical setting. METHODS: We designed a cohort study to collect all chart data of NSCLC patients treated with EGFR TKI in our institution from February 2012 to December 2015 retrospectively and followed up the clinical outcome of EGFR TKI monotherapy or therapy in combination with chemotherapy until April 2017 prospectively. All eligible patients had to meet the criteria of gradual progression. The time interval of progression-free survival 1 (PFS1, gradual progression or death) to PFS2 (off-EGFR TKI progression), and overall survival (OS) between the above 2 groups were used in survival analysis. RESULTS: In all, 50 patients were included in our study. Patients' baseline characteristics were well balanced. Exon 19 deletion mutations and L858R point mutations were detected in 16 and 8 patients, respectively. Twenty, 22, and 8 patients were treated with EGFR TKI in the first, second, and third line setting, respectively. The time interval from PFS1 to PFS2 was 92 and 37 days (monotherapy vs combination), respectively (hazard ratio [HR] =1.16, 95% confidence interval [CI]: 0.61-2.21, P=0.652). The median OS in the monotherapy group and combination group was 696 and 799 days, respectively (HR =0.74, 95% CI: 0.33-1.71, P=0.501). There were no statistical differences between the 2 groups in terms of the time interval from PFS1 to PFS2 and OS. CONCLUSION: Our results suggested that compared with EGFR TKI monotherapy, its combination with chemotherapy beyond gradual progression may not confer a significant survival benefit to NSCLC patients. Further prospective studies are warranted to reinforce the results of the study.

15.
Inorg Chem ; 56(3): 1504-1510, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-28094961

RESUMO

Hydrogenation is successfully employed to improve sensing performances of the gas sensors based on TiO2 nanosheets with exposed {001} facets for the first time. The hydrogenated TiO2 nanosheets show a significantly higher response toward ethanol, acetone, triethylamine, or formaldehyde than the samples without hydrogenation, and the response further increases with an increase of the hydrogenation temperature. The excellent sensing performances are ascribed to an increase of the density of unsaturated Ti5c atoms on the {001} surface resulting from the hydrogenation process. The unsaturated Ti5c atoms are considered to serve as sensing reaction active sites. They can generate noncontributing (free) electrons and adsorb oxygen molecules, and the detailed sensing mechanism is described at atomic and molecule level. The hydrogenated strategy may be employed to enhance the sensing performances of other metal oxide sensors and catalytic reaction activities of catalyst. The concept of the surface unsaturated metal atoms serving as sensing reaction active sites not only deepens the understanding of the sensing reaction and catalytic reaction mechanism but also provides new insights into the design of advanced gas sensing materials, catalysts, and photoelectronic devices.

16.
Medicine (Baltimore) ; 96(48): e8944, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29310389

RESUMO

RATIONALE: Secondary systemic lupus erythematosus (SLE) is an exceedingly rare complication of thymoma resection and is difficult to diagnose because of the insidious and nonspecific clinical manifestations. A case of SLE that occurs secondary to thymoma resection is described in this report. PATIENT CONCERNS: A 43-year-old male came to our hospital with the sole symptom of dyspnea after thymoma resection initially. However, other atypical lesions of SLE occurred over time. DIAGNOSES: Antinuclear antibody spectrum test showed positive results and the diagnosis of SLE was obtained. INTERVENTIONS: Initially the patient was treated for medically unexplained dyspnea (MUD) without much improvement. Following the diagnosis, the methylprednisolone pulse therapy and therapies of immunoglobulin and cyclophosphamide were adopted for the treatment. OUTCOMES: Finally, the patient's symptoms faded rapidly and favorable prognosis has been maintained till now. LESSONS: This case highlights the importance of a serious and comprehensive analysis before we give the diagnosis of MUD. Additionally, ignorance of secondary SLE after thymoma resection should be prevented to avoid a delayed diagnosis and treatment.


Assuntos
Dispneia/diagnóstico , Dispneia/etiologia , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/etiologia , Timoma/cirurgia , Neoplasias do Timo/cirurgia , Adulto , Erros de Diagnóstico , Dispneia/tratamento farmacológico , Humanos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Masculino , Timoma/diagnóstico por imagem , Timoma/patologia , Neoplasias do Timo/diagnóstico por imagem , Neoplasias do Timo/patologia
17.
Cell Res ; 26(1): 34-45, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26704449

RESUMO

Recently, we reported a chemical approach to generate pluripotent stem cells from mouse fibroblasts. However, whether chemically induced pluripotent stem cells (CiPSCs) can be derived from other cell types remains to be demonstrated. Here, using lineage tracing, we first verify the generation of CiPSCs from fibroblasts. Next, we demonstrate that neural stem cells (NSCs) from the ectoderm and small intestinal epithelial cells (IECs) from the endoderm can be chemically reprogrammed into pluripotent stem cells. CiPSCs derived from NSCs and IECs resemble mouse embryonic stem cells in proliferation rate, global gene expression profile, epigenetic status, self-renewal and differentiation capacity, and germline transmission competency. Interestingly, the pluripotency gene Sall4 is expressed at the initial stage in the chemical reprogramming process from different cell types, and the same core small molecules are required for the reprogramming, suggesting conservation in the molecular mechanism underlying chemical reprogramming from these diverse cell types. Our analysis also shows that the use of these small molecules should be fine-tuned to meet the requirement of reprogramming from different cell types. Together, these findings demonstrate that full chemical reprogramming approach can be applied in cells of different tissue origins and suggest that chemical reprogramming is a promising strategy with the potential to be extended to more initial types.


Assuntos
Técnicas de Reprogramação Celular/métodos , Reprogramação Celular/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Intestino Delgado/citologia , Intestino Delgado/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/citologia
18.
Nat Commun ; 5: 5162, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25330787

RESUMO

Two-dimensional atomic crystals are extensively studied in recent years due to their exciting physics and device applications. However, a molecular counterpart, with scalable processability and competitive device performance, is still challenging. Here, we demonstrate that high-quality few-layer dioctylbenzothienobenzothiophene molecular crystals can be grown on graphene or boron nitride substrate via van der Waals epitaxy, with precisely controlled thickness down to monolayer, large-area single crystal, low process temperature and patterning capability. The crystalline layers are atomically smooth and effectively decoupled from the substrate due to weak van der Waals interactions, affording a pristine interface for high-performance organic transistors. As a result, monolayer dioctylbenzothienobenzothiophene molecular crystal field-effect transistors on boron nitride show record-high carrier mobility up to 10 cm(2) V(-1) s(-1) and aggressively scaled saturation voltage ~1 V. Our work unveils an exciting new class of two-dimensional molecular materials for electronic and optoelectronic applications.

19.
Tumour Biol ; 35(9): 9419-27, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24957040

RESUMO

Aflibercept (Ziv-aflibercept, VEGF Trap, AVE005) is an engineered protein that functions as a decoy receptor to bind vascular endothelial growth factor A (VEGF-A). Hemorrhagic events, including epistaxis, gastrointestinal bleeding, and pulmonary bleeding, is one of its major adverse effects, but the incidence rate and overall risk has not been systematically studied. Therefore, we conducted a meta-analysis of published clinical trials to investigate the incidence and relative risk of hemorrhagic events in cancer patients treated with aflibercept. Electronic databases including PubMed, Embase, Cochrane databases, and American Society of Clinical Oncology abstracts were searched. Eligible studies were phase II and III prospective clinical trials of cancer patients treated with aflibercept with toxicity profile on hemorrhagic events. Overall incidence rates, relative risk (RR), and 95 % confidence intervals (CI) were calculated using fixed or random effects models depending on the heterogeneity of the included studies. A total of 4,538 patients with a variety of solid tumors from 13 prospective clinical trials were included for the meta-analysis. The overall incidences of all-grade and high-grade hemorrhagic events in cancer patients were 22.1 % (95 % CI, 16.5-29.7 %) and 4.2 % (95 % CI, 3.9-4.6 %), respectively. The relative risks of hemorrhagic events of aflibercept compared to control were increased for all-grade (RR = 2.63; 95 % CI, 2.07-3.34) and high-grade (RR = 2.45, 95 % CI, 1.62-3.72) hemorrhagic events. The risk of developing high-grade hemorrhagic events with aflibercept was comparable to that of bevacizumab (RR = 1.26; 95 % CI, 0.89-1.79). Aflibercept is associated with an increased risk of developing hemorrhagic events in patients with solid tumors. Close monitoring and management of hemorrhagic events are recommended.


Assuntos
Hemorragia/induzido quimicamente , Neoplasias/tratamento farmacológico , Receptores de Fatores de Crescimento do Endotélio Vascular/efeitos adversos , Proteínas Recombinantes de Fusão/efeitos adversos , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Humanos , Estudos Prospectivos , Receptores de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Medição de Risco/estatística & dados numéricos , Fatores de Risco
20.
Zhonghua Yi Xue Za Zhi ; 92(24): 1702-5, 2012 Jun 26.
Artigo em Chinês | MEDLINE | ID: mdl-22944163

RESUMO

OBJECTIVE: To explore the effects of lipopolysaccharide (LPS)-induced myeloid-derived suppressor cells (MDSCs) on the proliferation of spleen T lymphocytes. METHODS: BALB/c mice were randomly divided into two groups: LPS group and normal control group. They were injected intraperitoneally with LPS and normal saline solution respectively. MDSCs were separated with CD11b immunomagnetic beads from the spleen extract of mice. The morphological characteristics of MDCSs were observed by Wright-Giemsa staining and the characteristic molecules on cell surface identified by flow cytometry. And the effects of MDSCs on the in vitro proliferation of T cells were determined by methyl-thiazolyl-tetrazolium bromide (MTT). RESULTS: The proportion of MDSCs in the spleen of the LPS group was much more than that of the normal control group (27.4% ± 6.6% vs 5.1% ± 3.8%; t = 5.06, P = 0.007). CD11b(+)Gr-1(+)MDSCs could be separated by CD11b immunomagnetic beads from the spleen of mice injected with LPS at a high purity of 84.0% ± 4.2%. MTT method showed that the proliferation of T cells decreased significantly after a co-cultivation with CD11b(+)MDSCs versus the control group. And it was positively correlated with the number of MDSCs (F = 46.26, P = 0.000). CONCLUSIONS: A high purity of LPS-induced myeloid-derived suppressor cells may be separated with CD11b immunomagnetic beads. And it has dose-dependent inhibitory effects on the proliferation of the spleen T lymphocytes.


Assuntos
Proliferação de Células/efeitos dos fármacos , Lipopolissacarídeos/efeitos adversos , Células Mieloides/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Animais , Células Cultivadas , Técnicas de Cocultura , Camundongos , Camundongos Endogâmicos BALB C , Células Mieloides/citologia , Baço/citologia , Linfócitos T Reguladores/citologia
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