Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Nanotechnol ; 15(2): 145-153, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31988501

RESUMO

Human epidermal growth factor receptor 2 (HER2) is overexpressed in >20% of breast cancers. Dimerization of HER2 receptors leads to the activation of downstream signals enabling the proliferation and survival of malignant phenotypes. Owing to the high expression levels of HER2, combination therapies are currently required for the treatment of HER2+ breast cancer. Here, we designed non-toxic transformable peptides that self-assemble into micelles under aqueous conditions but, on binding to HER2 on cancer cells, transform into nanofibrils that disrupt HER2 dimerization and subsequent downstream signalling events leading to apoptosis of cancer cells. The phase transformation of peptides enables specific HER2 targeting, and inhibition of HER2 dimerization blocks the expression of proliferation and survival genes in the nucleus. We demonstrate, in mouse xenofraft models, that these transformable peptides can be used as a monotherapy in the treatment of HER2+ breast cancer.

2.
Virulence ; 11(1): 39-48, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31851866

RESUMO

Metformin, as the first-line oral drug for type 2 diabetes, has proven benefits against aging, cancer and cardiovascular diseases. But the influence of metformin to the immune response and its molecular mechanisms remain obscure. Metformin increases resistance to not only the Gram-negative pathogens Pseudomonas aeruginosa and Salmonella enterica but also the Gram-positive pathogens Enterococcus faecalis and Staphylococcus aureus. Meanwhile, metformin protects the animals from the infection by enhancing the tolerance to the pathogen infection rather than by reducing the bacterial burden. Through the screening of classical immune pathways in C. elegans, we find metformin enhances innate immunity through p38 MAPK pathway. Furthermore, activated p38/PMK-1 by metformin acts on the intestine for innate immune response. In addition, metformin-treated mice have increased resistance to P. aeruginosa PA14 infection and significantly increased the levels of active PMK-1. Therefore, promoted p38/PMK-1-mediated innate immunity by metformin is conserved from worms to mammals. Our work provides a conserved mechanism by which metformin enhances immune response and boosts its therapeutic application in the treatment of pathogen infection.

3.
Front Oncol ; 9: 1201, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31803610

RESUMO

Tumor cells, including cancer stem cells (CSCs) resistant to radio- and chemotherapy, must enhance metabolism to meet the extra energy demands to repair and survive such genotoxic conditions. However, such stress-induced adaptive metabolic alterations, especially in cancer cells that survive radiotherapy, remain unresolved. In this study, we found that CPT1 (Carnitine palmitoyl transferase I) and CPT2 (Carnitine palmitoyl transferase II), a pair of rate-limiting enzymes for mitochondrial fatty acid transportation, play a critical role in increasing fatty acid oxidation (FAO) required for the cellular fuel demands in radioresistant breast cancer cells (RBCs) and radiation-derived breast cancer stem cells (RD-BCSCs). Enhanced CPT1A/CPT2 expression was detected in the recurrent human breast cancers and associated with a worse prognosis in breast cancer patients. Blocking FAO via a FAO inhibitor or by CRISPR-mediated CPT1A/CPT2 gene deficiency inhibited radiation-induced ERK activation and aggressive growth and radioresistance of RBCs and RD-BCSCs. These results revealed that switching to FAO contributes to radiation-induced mitochondrial energy metabolism, and CPT1A/CPT2 is a potential metabolic target in cancer radiotherapy.

4.
J Cancer ; 10(22): 5536-5548, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632497

RESUMO

Glioblastoma (GBM) is one of the lethal tumors with poor prognosis. However, prognostic prediction approaches need to be further explored. Therefore, we developed an evaluation system that could be used for prognostic prediction of GBM patients. Published mRNA expression datasets from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Chinese Glioma Genome Atlas (CGGA) were analyzed. Quantitative Realtime-PCR of signature genes and molecular aberrations of 178 Xiangya GBM patients were used for confirmation. Gene set enrichment analysis (GSEA) was performed for functional annotation. As a result, we established a 13-gene signature which named Combined Therapy Sensitivity Index (CTSI). Based on a cutoff point, we divided patients into high-risk group and low-risk group. Based on Kaplan-Meier analysis and multivariate Cox regression analysis, we found that patients in the high-risk group had a shorter overall survival time than patients in the low-risk group (p<0.001 in TCGA and CGGA datasets, p=0.047 in GSE4271 dataset, p=0.008 in Xiangya GBM cohort, HR: 1.65-3.42). By comparing the status of IDH mutation, TERT promoter mutation (TERTp-mut) and MGMT promoter methylation, CTSI was predictable in IDH wild-type (IDH-wt)/MGMT promoter unmethylated (MGMTp-unmeth) patients (p=0.037 in IDH-wt/TERTp-mut/MGMTp-unmeth subgroup, HR: 1.98; p=0.032 in IDH-wt/TERTp-wt/MGMTp-unmeth subgroup, HR: 2.09). Based on GESA, the Gene Ontology (GO) gene sets were enriched differently between CTSI high-risk and low-risk groups. Our results showed CTSI risk score can predict the prognosis of IDH-wt/MGMTp-unmeth GBM patients. Based on CTSI, combined with the status of IDH mutation, TERT promoter mutation and MGMT promoter methylation, a stepwise prognosis evaluation system which can provide precise prognosis prediction for GBM patients was established.

5.
Am J Transl Res ; 11(6): 3816-3824, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31312391

RESUMO

The prognosis of patients with advanced hepatocellular carcinoma (HCC) remains obscure. From a clinical point of view, the ERK MAPK pathway and the PI3K/AKT pathway are activated in the majority of liver cancer. In addition, long term used to single agent treatment of HCC, frequently results in reverse activation of the ERK MAPK pathway or the PI3K/AKT pathway, leading to drug resistance. Thus, it is important to research the mechanism of combination agents that could suppress different pathways to treat HCC. Here, we found that combination natural product magnolin with BRAF inhibitor SB590885 synergistically suppressed the proliferation, promoted cell cycle arrest and apoptosis in hepatocellular carcinoma cells Bel-7402 and SK-Hep1. Furthermore, we demonstrated that the magnolin and the SB590885 combination led to increased impaired proliferation via inhibition of the ERK MAPK pathway and the PI3K/AKT pathway. These findings highlight the important role of agent combination and provided the approaches of therapeutic improvement for patients with advanced HCC.

6.
Mater Sci Eng C Mater Biol Appl ; 102: 45-52, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147016

RESUMO

Tyrosinase inhibitors could effectively limit the activity of tyrosinase in melanocytes to reduce the excessive synthesis and deposition of melanin. However, low skin permeability and lacking in targeting greatly restricted their application. Herein, ZnO quantum dots were synthesized by gel-sol method and grafted with BQ-788, which have been employed as transdermal and targeting carrier to delivery ellagic acid to melanocytes. Ellagic acid loaded ZnO quantum dots with the size distribution of around 9 nm could targetedly bind to melanocytes and enter the melanocytes by endocytosis within 1 h. The ellagic acid release behavior was controlled by the decreasing of pH via the rapid dissolution of ZnO. When the concentration of BQ-788/EA@ZnO was 12.5 µg/mL, the inhibition rate on tyrosinase activity and melanin deposition were up to 44.23 ±â€¯4.97% and 37.50 ±â€¯5.23%, respectively. In view of their good biocompatibility, they were of great potential in clinically external application for tyrosinase inhibition.


Assuntos
Ácido Elágico/química , Inibidores Enzimáticos/farmacologia , Melanócitos/enzimologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Pontos Quânticos/química , Óxido de Zinco/química , Administração Cutânea , Adulto , Materiais Biocompatíveis/farmacologia , Células Cultivadas , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Endocitose/efeitos dos fármacos , Humanos , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Monofenol Mono-Oxigenase/metabolismo , Oligopeptídeos/síntese química , Oligopeptídeos/química , Piperidinas/síntese química , Piperidinas/química , Pontos Quânticos/ultraestrutura , Tirosina/metabolismo , Óxido de Zinco/síntese química
7.
Redox Biol ; 24: 101189, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30986607

RESUMO

Radiotherapy (RT) is the major modality for control of glioblastoma multiforme (GBM), the most aggressive brain tumor in adults with poor prognosis and low patient survival rate. To improve the RT efficacy on GBM, the mechanism causing tumor adaptive radioresistance which leads to the failure of tumor control and lethal progression needs to be further elucidated. Here, we conducted a comparative analysis of RT-treated recurrent tumors versus primary counterparts in GBM patients, RT-treated orthotopic GBM tumors xenografts versus untreated tumors and radioresistant GBM cells versus wild type cells. The results reveal that activation of STAT3, a well-defined redox-sensitive transcriptional factor, is causally linked with GBM adaptive radioresistance. Database analysis also agrees with the worse prognosis in GBM patients due to the STAT3 expression-associated low RT responsiveness. However, although the radioresistant GBM cells can be resensitized by inhibition of STAT3, a fraction of radioresistant cells can still survive the RT combined with STAT3 inhibition or CRISPR/Cas9-mediated STAT3 knockout. A complementally enhanced activation of ERK1/2 by STAT3 inhibition is identified responsible for the survival of the remaining resistant tumor cells. Dual inhibition of ERK1/2 and STAT3 remarkably eliminates resistant GBM cells and inhibits tumor regrowth. These findings demonstrate a previously unknown feature ofSTAT3-mediated ERK1/2 regulation and an effective combination of two targets in resensitizing GBM to RT.

8.
Cancer Lett ; 443: 56-66, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30481564

RESUMO

A mammalian cell houses two genomes located separately in the nucleus and mitochondria. During evolution, communications and adaptations between these two genomes occur extensively to achieve and sustain homeostasis for cellular functions and regeneration. Mitochondria provide the major cellular energy and contribute to gene regulation in the nucleus, whereas more than 98% of mitochondrial proteins are encoded by the nuclear genome. Such two-way signaling traffic presents an orchestrated dynamic between energy metabolism and consumption in cells. Recent reports have elucidated the way how mitochondrial bioenergetics synchronizes with the energy consumption for cell cycle progression mediated by cyclin B1/CDK1 as the communicator. This review is to recapitulate cyclin B1/CDK1 mediated mitochondrial activities in cell cycle progression and stress response as well as its potential link to reprogram energy metabolism in tumor adaptive resistance. Cyclin B1/CDK1-mediated mitochondrial bioenergetics is applied as an example to show how mitochondria could timely sense the cellular fuel demand and then coordinate ATP output. Such nucleus-mitochondria oscillation may play key roles in the flexible bioenergetics required for tumor cell survival and compromising the efficacy of anti-cancer therapy. Further deciphering the cyclin B1/CDK1-controlled mitochondrial metabolism may invent effect targets to treat resistant cancers.


Assuntos
Proteína Quinase CDC2/metabolismo , Ciclina B1/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias/metabolismo , Animais , Ciclo Celular , Núcleo Celular/metabolismo , Metabolismo Energético , Humanos , Mitocôndrias/metabolismo
9.
World Neurosurg ; 119: e262-e271, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30053568

RESUMO

OBJECTIVE: To assess the application of functional neuronavigation in surgeries of adult cerebral gliomas. METHODS: We performed a retrospective analysis of 375 cases of adult cerebral glioma patients who underwent microsurgical treatment between 2011 and 2017 in our department. Among them, 142 patients underwent surgery using functional neuronavigation (group A), and the other 233 patients were operated on without the help of functional neuronavigation (group B). For both groups, we categorized them into several subgroups according to the lesion locations. RESULTS: A significant difference in the gross total resection rate was observed between group A and group B (P = 0.001 for overall; P = 0.036 for EO area; and P = 0.004 for BBT area). The postoperative complication rate of group A was much lower than that of group B (P = 0.003 for overall; and P = 0.016 for BBT area). The postoperative 6-month Karnofsky Performance Scale score of all patients in group A was significantly higher than that of group B. Kaplan-Meier survival analyses showed significant increases in the median survival time of group A compared with that of group B (P < 0.001 for overall; P = 0.012 for EO area; P = 0.006 for BBT area), and the Cox proportional regression analysis estimated the hazard ratio of the functional neuronavigation to be 0.533, helping reduce the risk of death by 46.7%. CONCLUSIONS: This study confirmed that the application of neuronavigation in adult glioma surgery can improve postoperative quality of life and lengthen the survival time of patients, especially in cases involving the brainstem and the eloquent area.


Assuntos
Neoplasias Encefálicas/cirurgia , Glioma/cirurgia , Microcirurgia/métodos , Neuronavegação/métodos , Adolescente , Adulto , Neoplasias Encefálicas/diagnóstico por imagem , Feminino , Glioma/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
10.
Turk J Med Sci ; 47(4): 1239-1246, 2017 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-29156869

RESUMO

Background/aim: Warfarin is a common anticoagulant with large interindividual differences and a narrow therapeutic range. The polymorphisms of gamma-glutamyl carboxylase (GGCX) are important genetic factors for warfarin dose requirements. Materials and methods: Polymerase chain reaction and direct sequencing methods were used to detect the GGCX rs699664 genotype in 215 atrial fibrillation (AF) patients with warfarin administration. The effects on warfarin dose by different genotypes were analyzed. A warfarin dosing algorithm was developed based on age, height, CYP2C9, VKORC1, and GGCX genotype. Results: In 215 AF patients, there were 104 cases of wild-type GG genotype (48.4%), 92 cases of GA genotype (42.8%), and 19 cases of AA genotype (8.8%). Patients with the GGCX rs699664 A allele (GA or AA genotypes) needed higher warfarin doses than those with the GG genotype (P < 0.05). A warfarin dosing algorithm showed that age, height, CYP2C9, VKORC1, and GGCX genotype were the best variables for estimating warfarin dose (R2 = 41.2%). Another independent cohort of 60 AF patients showed a significant linear correlation between predicted warfarin maintenance dose and actual dose (R = 0.660, P < 0.01). Conclusion: AF patients with the GA and AA genotypes in GGCX rs699664 required significantly higher warfarin doses. GGCX rs699664 is a potential predictor for the warfarin dose of AF patients.

11.
Nano Lett ; 17(8): 4860-4865, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28732157

RESUMO

Single nanowire lasers based on bottom-up III-V materials have been shown to exhibit room-temperature near-infrared lasing, making them highly promising for use as nanoscale, silicon-integrable, and coherent light sources. While lasing behavior is reproducible, small variations in growth conditions across a substrate arising from the use of bottom-up growth techniques can introduce interwire disorder, either through geometric or material inhomogeneity. Nanolasers critically depend on both high material quality and tight dimensional tolerances, and as such, lasing threshold is both sensitive to and a sensitive probe of such inhomogeneity. We present an all-optical characterization technique coupled to statistical analysis to correlate geometrical and material parameters with lasing threshold. For these multiple-quantum-well nanolasers, it is found that low threshold is closely linked to longer lasing wavelength caused by losses in the core, providing a route to optimized future low-threshold devices. A best-in-group room temperature lasing threshold of ∼43 µJ cm-2 under pulsed excitation was found, and overall device yields in excess of 50% are measured, demonstrating a promising future for the nanolaser architecture.

12.
Cancer Lett ; 405: 46-55, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28642170

RESUMO

lncRNAs regulate the initiation and progression of osteosarcoma, although the mechanism by which this occurs remains unknown. The present study shows that over-expression of the lncRNA DANCR increased osteosarcoma cell proliferation, migration, and invasion in vitro, as well as promoted xenograft tumor growth and lung metastasis in vivo. Mechanistically, DANCR promoted osteosarcoma progression by mediating cancer stem cells (CSCs) features. Moreover, pull-down assays and luciferase reporter assays indicated that DANCR upregulated expression of the receptor tyrosine kinase AXL by competitively binding to miR-33a-5p. Furthermore, DANCR enhanced the expression of proteins downstream of the AXL-Akt pathway. DANCR was consistently significantly increased in osteosarcoma tissues, and its expression was positively correlated with tumor size and metastasis as an independent poor prognostic factor. Furthermore, both in patient tumors and xenograft tumors, DANCR expression was positively related to AXL and negatively related to miR-33a-5p. Taken together, our results suggest that DANCR is a crucial upregulator of osteosarcoma and an independent predictor of prognosis. DANCR increases CSCs function by upregulating AXL via competitively binding to miR-33a-5p, and this function is sequentially performed through the PI3K-Akt signaling pathway.


Assuntos
Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/patologia , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Proteínas Proto-Oncogênicas/metabolismo , RNA Longo não Codificante/fisiologia , Receptores Proteína Tirosina Quinases/metabolismo , Análise de Variância , Animais , Biomarcadores Tumorais , Proliferação de Células , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Nus , Prognóstico , Células Tumorais Cultivadas , Regulação para Cima
13.
World Neurosurg ; 101: 457-465, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28192265

RESUMO

OBJECTIVES: To compare and analyze the differences in clinical manifestations and surgical outcomes after gross total resection (GTR) for vestibular schwannoma between elderly and younger patients. METHODS: We conducted a retrospective study of 40 elderly (≥65 years) and 40 younger (<65 years) patients, and matched operation dates and tumor size in the 2 groups were matched. All 80 patients underwent microsurgical resection though the sigmoid approach, by the same surgeon (X.Y.). We then summarized clinical manifestations, image data, perioperative complications, tumor recurrence, and functional outcomes and assessed the differences between the 2 groups. RESULTS: The mean follow-up time was 52.64 months. Elderly patients had a poorer preoperative American Society of Anesthesiology physical status scores than younger patients (62.5% vs. 30%, P = 0.004) and were more likely to have balance disorders (72.5% vs. 25%, P < 0.01), without other preoperative differences. Both groups of patients achieved GTR. The incidence of infection was slightly but not significantly greater in elderly patients (P > 0.05). There were also no significant differences in perioperative complications, recurrence rate, facial nerve function, hearing level, or Karnofsky Performance Status Scale scores between younger and older patients. CONCLUSIONS: Elderly patients tended to suffer from poorer health (American Society of Anesthesiology score) and poor balance before the operation; however, they did not experience more complications, worse nerve function, or worse quality of life in the perioperative or follow-up times. We conclude that GTR of vestibular schwannomas, even large or giant ones, is a safe and effective option for elderly patients.


Assuntos
Microcirurgia/tendências , Neuroma Acústico/diagnóstico por imagem , Neuroma Acústico/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Adulto , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Microcirurgia/efeitos adversos , Pessoa de Meia-Idade , Neuroma Acústico/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento
14.
World Neurosurg ; 99: 584-592, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28017751

RESUMO

BACKGROUND: Solitary fibrous tumors (SFTs) are rare mesenchymal tumors that occasionally occur in the central nervous system (CNS). It is difficult to fully understand their clinical characteristics, partly due to a limited number of reported cases. METHODS: We reviewed 24 patients admitted to our institution between 2009 and 2016 with CNS solitary fibrous tumors. We reviewed and analyzed patient profiles, such as demographics, presentations, imaging studies, extent of resection, and adjuvant treatment. Differences between malignant and benign SFTs were assessed using the χ2 test or Student's t-test. Kaplan-Meier analysis was used to estimate the disease-free survival (DFS) rate. The multivariate Cox regression analysis was performed to evaluate the possible predictive value of the DFS rate of the previously mentioned covariates. RESULTS: A total of 13 men and 11 women were enrolled in the study (the average age was 43). The median follow-up time was 58 months. Twenty-one patients underwent gross total resection (GTR), and 3 patients received a subtotal resection (STR). The tumors in 15 patients (62.5%) were atypical or malignant. One patient (4.2%) suffered SFT-related death (multiple organ failure by tumor metastasis), and 3 patients (12.5%) experienced tumor recurrence. We found that a large tumor size (≥10 cm, P < 0.001) and STR (P < 0.001) were negatively associated with the DFS rate. CONCLUSION: CNS SFTs are rare, slow-growing, less aggressive, and recrudescent tumors. Complete resection is the most effective therapy. Large tumor size and STRs might shorten DFS time.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias do Sistema Nervoso Central/cirurgia , Tumores Fibrosos Solitários/cirurgia , Adulto , Idoso , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Modelos de Riscos Proporcionais , Radiocirurgia , Radioterapia Adjuvante , Estudos Retrospectivos , Tumores Fibrosos Solitários/diagnóstico por imagem , Tumores Fibrosos Solitários/metabolismo , Tumores Fibrosos Solitários/patologia , Tomografia Computadorizada por Raios X , Carga Tumoral , Adulto Jovem
15.
Nano Lett ; 16(8): 5080-6, 2016 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-27459233

RESUMO

We present the design and room-temperature lasing characteristics of single nanowires containing coaxial GaAs/AlGaAs multiple quantum well (MQW) active regions. The TE01 mode, which has a doughnut-shaped intensity profile and is polarized predominantly in-plane to the MQWs, is predicted to lase in these nanowire heterostructures and is thus chosen for the cavity design. Through gain and loss calculations, we determine the nanowire dimensions required to minimize loss for the TE01 mode and determine the optimal thickness and number of QWs for minimizing the threshold sheet carrier density. In particular, we show that there is a limit to the minimum and maximum number of QWs that are required for room-temperature lasing. Based on our design, we grew nanowires of a suitable diameter containing eight uniform coaxial GaAs/AlGaAs MQWs. Lasing was observed at room temperature from optically pumped single nanowires and was verified to be from TE01 mode by polarization measurements. The GaAs MQW nanowire lasers have a threshold fluence that is a factor of 2 lower than that previously demonstrated for room-temperature GaAs nanowire lasers.

16.
Biomed Rep ; 4(4): 453-458, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27073631

RESUMO

The polymorphisms of cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex 1 (VKORC1) are important genetic factors for warfarin dose determinations. The present study aimed to investigate the contribution of the CYP2C9 and VKORC1 genotypes to warfarin dose requirement in atrial fibrillation (AF) patients, and to evaluate the clinical application of a warfarin-dosing algorithm. A total of 122 AF patients with a target international normalized ratio of 2.0 to 3.0 were included to determine the genotypes of CYP2C9 (rs1057910) and VKORC1 (rs9923231). A warfarin-dosing algorithm was developed based on age, height, and the CYP2C9 and VKORC1 genotypes of AF patients. The results indicated that the mean warfarin daily dose requirement was lower in the CYP2C9*1/*3 genotype compared with those in the homozygous wild-type CYP2C9*1/*1 patients (P<0.05), and was higher in patients with the VKORC1 AG and GG genotypes compared with those with the AA genotype (P<0.05). The multivariate regression model showed that age, height, and the CYP2C9 and VKORC1 genotypes were the best variables for estimating warfarin dose (R2=56.4%). A new warfarin-dosing algorithm was developed and its validity was confirmed in a second cohort of AF patients. During the 50-day follow-up, 63.3% (19/30) of control group patients and 86.7% (26/30) of patients in the experimental group acquired the warfarin maintenance dose. Among all the patients who acquired the warfarin maintenance dose, the mean time elapse from initiation until warfarin maintenance dose was significantly less in the experimental group (25.8±1.7 day) compared to the control group (33.1±1.9 day) (P<0.05). There was significant linear correlation between predicted warfarin maintenance dose and actual dose (r=0.822, P<0.01). In conclusion, a new warfarin-dosing algorithm was developed based on the CYP2C9 and VKORC1 genotypes, and it can shorten the time elapse from initiation until warfarin maintenance dose in AF patients with warfarin therapy.

17.
Nano Lett ; 16(2): 1392-7, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26784952

RESUMO

We use temperature-dependent photoluminescence (PL), photoluminescence imaging, and time-resolved photoluminescence measurements to gain insights into the localization of excitons in single 2 nm GaAs/AlGaAs quantum well tube nanowires. PL spectra reveal the coexistence of localized and delocalized states at low temperatures, with narrow quantum dot-like emission lines on the high energy side of a broad emission band, and delocalized states on the low energy side. We find that the high energy QD-like emissions are metastable, disappearing at higher temperatures with only delocalized states (quantum well tube ground states) surviving. By comparing temperature- and time-dependent PL, we develop a theoretical model which provides insights into the confinement potentials and relaxation dynamics which localize the excitons in these quantum well tube nanowires.

18.
Zhong Yao Cai ; 39(9): 1960-5, 2016 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-30207650

RESUMO

Objective: To study the influence of different concentrations of selenium on the growth and absorbing of Se,Cd,Pb,Hg and As in Trillium tschonoskii. Methods: Trillium tschonoskii was treated with different concentrations of exogenous selenium, arsenic and heavy metals,and then the mass growth, leaf area,root number and other indicators reflecting its growth rule were calculated. Atomic fluorescence method was used to measure the absorption contents of Se,Cd,Pb,Hg and As. Results: The relative mass growth,leaf area and root number of Trillium tschonoskii increased at first and then decreased with the increasing of exogenous selenium concentrations. When the concentration of selenium was 25 mg / kg,the relative mass growth,leaf area and root number of Trillium tschonoskii reached a maximum. When selenium concentrations was over than 30 mg / kg,it inhibited the growth and development of Trillium tschonoskii. Trillium tschonoskii absorbing Cd,Pb,Hg and As had a regular of first decreasing then increasing and last decreasing. It reached the lowest when selenium concentrations at the range of 10 ~ 15 mg / kg. . Conclusion: Selenium had both stimulating effect and inhibiting effect on the growth and development of Trillium tschonoskii. Different selenium concentrations have different effects in absorbing Cd,Pb,Hg and As of Trillium tschonoskii


Assuntos
Selenito de Sódio/química , Arsênico , Metais Pesados , Selênio , Trillium
19.
Nanoscale ; 7(48): 20531-8, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-26586279

RESUMO

We have observed very low disorder in high quality quantum well tubes (QWT) in GaAs-Al(0.4)Ga(0.6)As core-multishell nanowires. Room-temperature photoluminescence spectra were measured from 150 single nanowires enabling a full statistical analysis of both intra- and inter-nanowire disorder. By modelling individual nanowire spectra, we assigned a quantum well tube thickness, a core disorder parameter and a QWT disorder parameter to each nanowire. A strong correlation was observed between disorder in the GaAs cores and disorder in the GaAs QWTs, which indicates that variations in core morphology effectively propagate to the shell layers. This highlights the importance of high quality core growth prior to shell deposition. Furthermore, variations in QWT thicknesses for different facet directions was found to be a likely cause of intra-wire disorder, highlighting the need for accurate shell growth.

20.
Nano Lett ; 15(3): 1876-82, 2015 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-25714336

RESUMO

We use low-temperature photoluminescence, photoluminescence excitation, and photoluminescence imaging spectroscopy to explore the optical and electronic properties of GaAs/AlGaAs quantum well tube (QWT) heterostructured nanowires (NWs). We find that GaAs QWTs with widths >5 nm have electronic states which are delocalized and continuous along the length of the NW. As the NW QWT width decreases from 5 to 1.5 nm, only a single electron state is bound to the well, and no optical excitations to a confined excited state are present. Simultaneously, narrow emission lines (fwhm < 600 µeV) appear which are localized to single spatial points along the length of the NW. We find that these quantum-dot-like states broaden at higher temperatures and quench at temperatures above 80 K. The lifetimes of these localized states are observed to vary from dot to dot from 160 to 400 ps. The presence of delocalized states and then localized states as the QWTs become more confined suggests both opportunities and challenges for possible incorporation into quantum-confined device structures.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA