RESUMO
The interior of the Earth is a high temperature and high pressure environment. High temperatures cause important changes in the physical and chemical properties of minerals. An increase in temperature leads to significant changes in the molecular and lattice vibrations, elasticity, and seismic velocity of minerals. The high temperature vibrational spectroscopy (infrared and Raman) used to study these changes can provide highly significant understanding of the Earth's interior. During high temperature spectroscopy, the heating device that is used to heat the sample can work at a very high temperature (e.g., 1 500 â) because it has a cooling device surrounding it that is used to prevent the temperature of its environments from getting too high. However, radiation from its heating elements is intense and this will shine on and heat the objective lens of the focusing system for the spectroscopic light source, and this would result in damage to the lens. Thus, to avoid damage to the objective lens, an upper limit is placed on the heater temperature. The significance of this work is that it presents a method to exceed the present instrument's temperature limit so that we can perform in situ spectroscopy on samples at higher temperatures. This work extended the temperature limit for the sample to a higher temperature by using an air blower around the objective lens to create a gas flow around it. The gas flow serves to remove heat from the objective lens by forced convection and its turbulent flow also served to increase the rate of heat transport from the lens to the moving gas stream, which together prevented overheating of the objective lens. Our results have shown that although this device is simple, it was highly effective: for a sample temperature of 1 000 â, the objective lens temperature was reduced from ï½235 to ï½68 â. Using this device, we performed in situ high temperature Raman spectroscopy of forsterite up to a sample temperature of 1 300 â. The results agreed well with previous studies and demonstrated that with our simple air blower device, we can perform in situ high temperature spectroscopy up to 1 300 â without damaging the objective lens and without expensive components like a high temperature composite objective lens or a long focus objective lens.
RESUMO
Tree bark was used as the passive air sampler to evaluate polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) pollution and possible sources in Southern Jiangsu. The concentrations of PCBs and Σ7PBDEs were in the range of 0.58-5.19 ng/g dry weight (dw; mean 1.79 ng/g dw) and 17.9-243 pg/g dw (mean 74.7 pg/g dw), respectively. Tri-PCBs were the major PCB homologs, and technical PCB product Ar1242 was identified as the main source. BDE209 concentrations (4.29-456 ng/g dw) were relatively high, indicating that BDE209 pollution was serious in this region. The deca-BDE commercial mixture was the predominant commercial PBDE product used in this region. A good correlation was found between tree bark and polyurethane foam (PUF) disks in Σ6PCB monitoring, suggesting that both of them respond well to the gas-phase PCB monitoring.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Éteres Difenil Halogenados/análise , Casca de Planta/química , Bifenilos Policlorados/análise , China , Monitoramento Ambiental/estatística & dados numéricos , PoliuretanosRESUMO
Hypermethylation of tumor suppressor genes (TSGs) promoters by DNA methyltransferase (DNMT) can be observed in almost all cancers which represent a hallmark of carcinogenesis, including lung cancer. DNMT inhibitors (e.g.5-Aza-CR/CdR) reactivate TSGs to exert anti-cancer activity and have been applied into the clinical. However, it is cytotoxic even at low concentrations, which might be not directly related to DNA methylation. We here investigated an alternative strategy in the lung cancer therapy and aimed to estimate and compare its efficiency and side effects of knockdown of DNMT1 in vitro and in vivo. Lung cancer tissues (n=20) showed enhanced expression of DNMT1 than corresponding non-neoplastic tissues. Similar results were found in lung cancer cell lines A549 and H538. The treatment of 5-Aza-CR or knockdown of DNMT1 in vitro could inhibit the expressions of DNMT1 but restore the TSGs expressions including the Ras association domain family 1A (RASSF1A) and the adenomatous polyposis coli (APC) via the demethylation of its promoter region, which results in the decreased proliferation, increased apoptosis and impaired ability of migration. Importantly, knockdown of DNMT1 by siRNA in vivo also effectively demethylated the RASSF1A and APC promoter, elevated their expressions and limited tumor growth, which functioned like 5-Aza-CR but with alleviated side effects, suggesting that knockdown of DNMT1 might be potential strategy for the treatment of lung cancer with better tolerability.
RESUMO
Surface soil samples were collected from urban agglomeration of the Yangtze River Delta (YRD), China in 2003 and 2012, respectively. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were analyzed to determine if there were any changes in their levels and compositional profiles between the two sampling years. The concentrations of Σ8PBDEs ranged from 0.553 to 13.0 µg kg(-1)(with the mean of 3.31 µg kg(-1)) in the 2003 samples and from 1.01 to 43.2 µg/kg (with the mean of 10.0 µg kg(-1)) in the 2012 samples. The concentrations of Σ32PCBs ranged from 0.301 to 3.29 µg kg(-1)(with the mean of 1.01 µg kg(-1)) in the 2003 samples and from 0.205 to 3.96 µg/kg (with the mean of 0.991 µg kg(-1)) in the 2012 samples. The comparisons between the 2012 and 2003 data showed that PBDEs concentrations increased over the years, but PCB concentrations did not change much. BDE-209 was the major BDE congener in both the 2003 and 2012 samples, indicating that the dominant PBDE mixture production and usage in the YRD had been the commercial deca-BDE mixture. Investigation of the PBDE congener profiles indicated that there had been new input of octa-BDEs in this region in recent years. Little change was found for the pattern of PCBs congener profiles between 2 years' samples. As such, spatial distributions of PBDEs or PCBs in surface soil samples reflected a gradient (from high to low) from the central cities out to rural areas in both the 2003 and 2012 data. In addition, high concentrations of PBDEs were observed in the industrial and residential areas, whereas high concentrations of PCBs were only observed in the industrial areas.
Assuntos
Éteres Difenil Halogenados/análise , Bifenilos Policlorados/análise , Poluentes do Solo/análise , China , Rios/química , Solo/química , UrbanizaçãoRESUMO
Red blood cell transfusion is an effective method to treat acute hemorrhage and severe anemia. However, blood source from donors is very limited, and transfusion-transmitted diseases occurred frequently, thus threatening human health. Therefore, the safe, abundant and functional blood source is needed. Generation of blood cells from human pluripotent stem cells(hPSC) will offer alternative approach. Lots of studies have been focused on erythroid cell differentiation in vitro, including how to enhance efficiency and improve their function. In this review, the research advances on differentiation methods and the regulatory mechanism are summarized. In addition, the progress in PSC differentiation into erythrocytes and the problems to be solved are discussed briefly.
Assuntos
Diferenciação Celular , Eritrócitos/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Embrionárias/citologia , HumanosRESUMO
Thirty-three camphor tree bark samples were collected from Southern Jiangsu in August 2012. They were analyzed for organochlorine pesticides (OCPs), including hexachlorobenzene (HCB), DDTs (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT), trans-chlordane and cis-chlordane. The concentrations of HCB, sigma6 DDTs and sigma Chlordanes ranged (dw) from 0.31 ng x g(-1) to 1.81 ng x g(-1), 0.40 ng x g(-1) to 17.3 ng x g(-1) and n. d. to 1.03 ng x g(-1), respectively. Due to the high volatility, the spatial distribution of HCB in Southern Jiangsu was uniform. Compared to the other results, the HCB concentration in Southern Jiangsu was lower. The historical usage of technical DDT mixture and the dicofol-type DDT were the major sources of DDTs in southern Jiangsu. The TC/CC ratio is usually used to distinguish between aged and fresh chlordane. According to the ratio of TC/CC, the chlordane in the urban area was derived from the fresh application of technical chlordane, and that in the rural area was attributed to the historical usage.
Assuntos
Cinnamomum camphora/química , Monitoramento Ambiental , Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Casca de Planta/química , China , DDT/análise , Hexaclorobenzeno/análiseRESUMO
T-cell acute lymphoblastic leukemias (T-ALLs) are clonal lymphoid malignancies with a poor prognosis, and still a lack of effective treatment. Here we examined the interactions between the mammalian target of rapamycin (mTOR) inhibitor rapamycin and idarubicin (IDA) in a series of human T-ALL cell lines Molt-4, Jurkat, CCRF-CEM and CEM/C1. Co-exposure of cells to rapamycin and IDA synergistically induced T-ALL cell growth inhibition and apoptosis mediated by caspase activation via the intrinsic mitochondrial pathway and extrinsic pathway. Combined treatment with rapamycin and IDA down-regulated Bcl-2 and Mcl-1, and inhibited the activation of phosphoinositide 3-kinase (PI3K)/mTOR and extracellular signal-related kinase (ERK). They also played synergistic pro-apoptotic roles in the drug-resistant microenvironment simulated by mesenchymal stem cells (MSCs) as a feeder layer. In addition, MSCs protected T-ALL cells from IDA cytotoxicity by up-regulating ERK phosphorylation, while rapamycin efficiently reversed this protective effect. Taken together, we confirm the synergistic antitumor effects of rapamycin and IDA, and provide an insight into the potential future clinical applications of combined rapamycin-IDA regimens for treating T-cell malignancies.
Assuntos
Apoptose/efeitos dos fármacos , Idarubicina/farmacologia , Leucemia de Células T/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Microambiente Tumoral/efeitos dos fármacosRESUMO
OBJECTIVE: To explore the feasibility of establishing an animal model of chronic radiation-induced lung injury. METHODS: Twenty-eight New Zealand white rabbits were randomly divided into 3 groups (the right lung irradiation group, the whole lung irradiation group and the control group). Animal model of radiation-induced lung injury was established by high-does radiotherapy in the irradiation groups, then all rabbits underwent CT and pathological examinations at 1, 2, 4, 8, 12, 16 weeks, respectively after radiation. RESULTS: Within 4 weeks of irradiation, some rabbits in the right lung irradiation group and whole lung irradiation group died. CT and pathological examinations all showed acute radiation pneumonitis. At 8-12 weeks after irradiation, CT scanning showed ground glass samples signs, patchy shadows and fibrotic stripes. Pathological examination showed the fibrosis pulmonary alveolar wall thickened obviously. CONCLUSIONS: The clinical animal model of chronic radiation-induced lung injury which corresponds to practical conditions in clinic can be successfully established.
Assuntos
Alvéolos Pulmonares/patologia , Lesões Experimentais por Radiação/patologia , Pneumonite por Radiação/patologia , Animais , Estudos de Viabilidade , Coelhos , Lesões Experimentais por Radiação/diagnóstico por imagem , Pneumonite por Radiação/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
Atmosphere is regarded to be an important media in the environmental pollution research area. Passive air sampling was one of the effective complementary sampling techniques for the active high volume air sampler in recent decades. A regional scale investigation on the atmospheric polycyclic aromatic hydrocarbons (PAHs) was conducted in the Yangtze River Delta (YRD). Polyurethane foam based passive air samplers were used to collect the atmospheric PAHs from 31 sampling sites in this area. PAHs concentrations ranged from 10.1 ng x m(-1) to 367 ng x m(-3) in this study. The annual average concentration of benzo [a] pyrene (BaP) reached 2.25 ng x m(-3), which was two times higher exceeding the national standard, GB 3095-2012. The atmospheric PAHs during four seasons decreased in the following order: autumn > winter > spring > summer. Larger BaP excessive areas were found in autumn and winter than other seasons. Moreover, an obvious emission of BaP was confirmed during the winter time. Traffic related petroleum combustion, coal and biomass burning, and coke oven were identified as potential sources of atmospheric PAHs, contributing 38.1%, 42.4%, and 19.5%, respectively.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Estações do Ano , Atmosfera , Benzo(a)pireno/análise , China , Carvão Mineral , Coque , Rios , Análise Espaço-TemporalRESUMO
Polybrominated Diphenyl Ethers (PBDEs) were measured in camphor bark samples from 40 locations in Suzhou, Nantong and Wuxi, Jiangsu Province. The samples were extracted by accelerated solvent extraction (ASE) and analyzed using gas chromatography/mass spectrometry (GC-MS). The 8 PBDEs were detected in all samples and the average concentrations of total PBDEs (BDE28, 47, 100, 99, 153, 154, 183, 209) was 835 microg/kg lipid weight (ranged from 112 to 7 460 microg/kg lipid weight). The BDE209 was the main homologues and accounted for 65.7% -99.6% of sigma 8 PBDEs. The predominant commercial products source for PBDEs in bark was Deca-BDE commercial products. Concentration of sigma 8 PBDEs detected in central district of Nantong were significantly higher than those in industrial park, suggesting the discharge of industrial point source might be the main source of PBDEs in this city. No significant difference was found between the levels of sigma 8 PBDEs in camphor bark collected from Suzhou and Wuxi. It can be concluded that the two cities are contaminated interactionally by PBDEs through atmospheric dispersion. The homologue and congener profiles of penta-BDEs for camphor bark were not consistent with commercial products, atmosphere and dust soil, which related with adsorption effect of tree bark and degradation effect of PBDEs.
Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Éteres Difenil Halogenados/análise , Casca de Planta/química , China , Cinnamomum camphora/química , Cinnamomum camphora/crescimento & desenvolvimento , CidadesRESUMO
Soil samples in contaminated site of a historical HCH plant were collected and the levels and the distribution of HCH were analyzed and studied. The highest level of SigmaHCH was 271.72 mg kg(-1). The contamination of HCH was mainly in 0 - 40 cm depth of soil, while the concentration of HCH in 0 - 40 cm depth of soil was much more than that in 40 - 150 cm depth of soil. The concentration of beta-HCH was much more than other three kinds of isomers. The distribution of HCH in 0 - 20 cm depth of soil was calculated by Kriging model. The induration of the surface soil, which stopped the rainwater infiltrating, made theconcentration of HCH reduce with depth and made the depth of contaminated soil shallow.