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2.
Chemosphere ; 297: 134148, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35240158

RESUMEN

Fe2O3-Al2O3 catalysts applied for conversion of polyolefin plastic waste into multi-walled carbon nanotubes (MWCNTs) and H2 are typically produced by impregnation, co-precipitation or sol-gel synthesis at atmospheric pressure and temperatures below 100 °C. This study utilized hydrothermal conditions and established the role of precipitating agents (urea, N-methylurea and N,N'-dimethylurea) on properties and catalytic activity of Fe2O3-Al2O3 catalysts (Fe-u, Fe-mu and Fe-dmu, respectively). The precipitating agent played a key role in tailoring the properties, such as crystallization degree, surface area and reducibility. The precipitating agents influenced the yield and outer diameters of MWCNTs but did not affect graphitization degree. Among the synthesized catalysts, Fe-u had the largest surface area and preferential formation of the highly reducible α-Fe2O3 crystalline phase. As a result, Fe-u had the highest activity during conversion of pyrolysis gas from low-density polyethylene (LDPE) into MWCNTs, yielding 0.91 g·g-1-catalyst MWCNTs at 800 °C as compared to 0.42 and 0.14 g·g-1-catalyst using Fe-dmu and Fe-mu, respectively. Fe-dmu favored the growth of MWCNTs with smaller outer diameters. Fe-u demonstrated high efficiency during operation using a continuous flow of pyrolysis gas from a mixture of polyolefins (70 wt% polypropylene, 6 wt% LDPE and 24 wt% high density polyethylene) producing 4.28 g·g-1-catalyst MWCNTs at 3.2% plastic conversion efficiency and a stable H2 flow for 155 min (25-32 vol%). The obtained data demonstrate that the selection of an appropriate precipitating agent for hydrothermal synthesis allows for the production of highly active Fe2O3-Al2O3 catalysts for the upcycling of polyolefin plastic waste into MWCNTs and H2.

3.
Environ Pollut ; 290: 118015, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34488162

RESUMEN

Size and magnetic separation of incineration bottom ash (IBA) are common for ferrous metals recovery, however, their influences on the mineral phase and the element redistribution, and subsequently the induced variation of metal leaching potential herein remain limited understanding. The lack of research in this field may misunderstand IBA performances, cause confused results for comparison among various studies, and potentially lead to biased conclusions. We herein quantitatively investigate the effects of size and magnetic separation on the IBA based on element distribution, leaching behavior, morphology, and mineralogy with statistical analysis. For preparation, sieving was performed with the original IBA (to obtain 7 size-fractions termed as OR1-7, respectively), followed by magnetic separation of each, to further yield magnetic fractions (MF1-7) to discriminate nonmagnetic fractions (NF1-7). In this study, we show that size and magnetic separation may pose significant yet different impacts on different fractions, which would affect their leaching potential concerning their respective downstream applications.


Asunto(s)
Incineración , Metales Pesados , Ceniza del Carbón , Fenómenos Magnéticos , Metales Pesados/análisis , Minerales , Residuos Sólidos/análisis
4.
Ren Fail ; 43(1): 535-542, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33736580

RESUMEN

OBJECTIVES: Acute kidney injury (AKI) is a common complication after lung transplantation (LTx) which is closely related to the poor prognosis of patients. We aimed to explore potential risk factors and outcomes associated with early post-operative AKI after LTx. METHODS: A retrospective study was conducted in 136 patients who underwent LTx at our institution from 2017 to 2019. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guideline. Univariate and multivariate analyses were conducted to identify risk factors related to AKI. The primary outcome was the incidence of AKI after LTx. Secondary outcomes were associations between AKI and short-term clinical outcomes and mortality. RESULTS: Of the 136 patients analyzed, 110 developed AKI (80.9%). AKI was associated with higher baseline eGFR (odds ratio (OR) 1.01 (95% confidence interval (CI): 1.00-1.03)) and median tacrolimus (TAC) concentration (OR 1.15 (95% CI: 1.02-1.30)). Patients with AKI suffered longer mechanical ventilation days (p = .015) and ICU stay days (p = .011). AKI stage 2-3 patients had higher risk of 1-year mortality (HR 16.98 (95% CI: 2.25-128.45)) compared with no-AKI and stage 1 patients. CONCLUSIONS: Our results suggested early post-operative AKI may be associated with higher baseline eGFR and TAC concentrations. AKI stage 1 may have no influence on survival rate, whereas AKI stage 2-3 may be associated with increased mortality at 1-year.


Asunto(s)
Lesión Renal Aguda/etiología , Lesión Renal Aguda/mortalidad , Tasa de Filtración Glomerular , Trasplante de Pulmón/efectos adversos , Tacrolimus/sangre , Lesión Renal Aguda/sangre , Lesión Renal Aguda/fisiopatología , Anciano , Femenino , Humanos , Incidencia , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Respiración Artificial/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Factores de Tiempo
5.
Biosens Bioelectron ; 169: 112555, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32927348

RESUMEN

Exosomal microRNAs (miRNAs) have been explored as an extremely promising biomarker of liquid biopsy for the diagnosis, treatment and prognosis of diseases such as cancer, in which sensitive and selective detection is significant. Herein, we describe the construction and testing of an electrochemical biosensor for the sensitive detection of exosomal miRNAs. It is based on synthetizing numerous long single-stranded DNAs (ssDNAs), which are produced by dual amplification reactions of target-triggered cyclic strand displacement reaction (TCSDR) and primer exchange DNA amplification reaction (PEDAR). In the first signal amplification step, target miRNAs are captured by the hairpin DNA strands (capture probes, Cp) that are immobilized on electrode. After strand unfolding with target capture, primer probes (Pp) enable to hybridize with Cp. And then target miRNAs were displaced for starting the TCSDR process that enable the introduction of numerous primers in Pp. In the second signal amplification step, the primers associated with PEDAR produce copious amounts of elongated ssDNAs. These ssDNAs absorb abundant quantities of methylene blue (MB) that enables the highly sensitive and label-free detection of exosomal miRNAs. This dual amplification process is characterized by a low limit of detection (LOD) of 3.04 aM. In addition, the electrochemical biosensor exhibits good selectivity for miR-21 detection, and shows benefits of simple operation, low cost, portability. Overall, the electrochemical biosensor provides a promising platform for the early diagnosis and screening of tumor biomarkers and the development of devices for point-of-care testing (POCT).


Asunto(s)
Técnicas Biosensibles , MicroARNs , ADN de Cadena Simple/genética , Técnicas Electroquímicas , Límite de Detección , MicroARNs/genética , Técnicas de Amplificación de Ácido Nucleico
6.
J Hazard Mater ; 387: 121256, 2020 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-31951979

RESUMEN

Flexible plastic packaging waste causes serious environmental issues due to challenges in recycling. This study investigated the conversion of flexible plastic packaging waste with 11.8 and 27.5 wt.% polyethylene terephthalate (PET) (denoted as PET-12 and PET-28, respectively) into oil and multi-walled carbon nanotubes (MWCNTs). The mixtures were initially pyrolyzed and the produced volatiles were processed over 9.0 wt.% Fe2O3 supported on ZSM-5 (400 °C) to remove oxygenated hydrocarbons (catalytic cracking of terephthalic and benzoic acids) that deteriorate oil quality. The contents of oxygenated hydrocarbons were decreased in oil from 4.6 and 9.4 wt.% per mass of PET-12 and PET-28, respectively, to undetectable levels. After catalytic cracking, the oil samples had similar contents of gasoline, diesel and heavy oil/wax fractions. The non-condensable gas was converted into MWCNTs over 0.9 wt.% Ni supported on CaCO3 (700 °C). The type of plastic packaging influenced the yields (2.4 and 1.5 wt.% per mass of PET-12 and PET-28, respectively) and the properties of MWCNTs due to the differences in gas composition. Regarding the electrocatalytic application, both MWCNTs from PET-12 and PET-28 outperformed commercial MWCNTs and Pt-based electrodes during oxygen evolution reaction, suggesting that MWCNTs from flexible plastic packaging can potentially replace conventional electrode materials.

7.
J Clin Pharm Ther ; 45(5): 983-990, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31985852

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: Teicoplanin is widely used for the treatment of infections caused by drug-resistant Gram-positive bacteria. Since there is a good correlation between trough levels and clinical outcome, therapeutic drug monitoring (TDM) is recommended to achieve better clinical curative effects. However, TDM of teicoplanin is not routine in China. So, a programme was initiated in 2017, including both HPLC method establishment and interlaboratory quality assessment, for the measurement of teicoplanin. METHODS: A main centre and a quality control centre were set up in the study. An HPLC-based method of teicoplanin determination in plasma was developed by the main centre. Analysis was performed using a Waters Symmetry C18 column (250 mm × 4.6 mm, 5 µm). The mobile phase was NaH2 PO4 (0.01 mol/L) and acetonitrile (75:25 v/v; pH 3.3), with a flow rate of 1.0 mL/min and a detection wavelength of 215 nm. Piperacillin sodium was selected as an internal standard (IS). Twenty-six additional TDM centres were then recruited to adopt this method. Then, all the centres were asked to take part in a quality control assessment evaluated by the quality control centre. RESULTS: For all TDM centres, linearity of teicoplanin concentration ranges was between 3.125 and 100 µg/mL. Intraday and interday accuracies ranged from 87.1% to 118.4%. Intraday and interday precision ranged from 0.3% to 13.8%. Therapeutic drug monitoring centres all passed inter-room quality assessment. All samples tested met the acceptance criteria. Then, 542 samples were collected. Patients with sub-optimal (≤10 mg/L) plasma teicoplanin concentrations constituted 42% of the total study population. WHAT IS NEW AND CONCLUSIONS: For the first time, a simple, rapid and accurate HPLC method for determining teicoplanin levels was successfully applied to therapeutic drug monitoring in clinical practice for twenty-seven TDM centres in China. The results demonstrated excellent interlaboratory agreement for teicoplanin testing and provide support for clinical laboratory quality management and results inter-accreditation.


Asunto(s)
Antibacterianos/sangre , Monitoreo de Drogas/métodos , Laboratorios/normas , Teicoplanina/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , China , Cromatografía Líquida de Alta Presión , Humanos , Persona de Mediana Edad , Control de Calidad , Reproducibilidad de los Resultados , Teicoplanina/administración & dosificación , Adulto Joven
8.
Oxid Med Cell Longev ; 2019: 7902874, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31772709

RESUMEN

Generally, depression is the result of complex gene-environment interactions. Recent studies have showed that the gut microbiota can affect brain function through the microbiota-gut-brain axis. However, the underlying mechanism of the microbiota and potential influence of depression remain elusive. We aimed to determine how gut microbiome contributes to the process of depression and further influences the host. Chronic unpredictable mild stress (CUMS) is used to establish a depression model. Fecal microbiota transplant (FMT) is applied to illustrate that depression can be transmitted via microbiota, and metabolism of liver analysis is applied to demonstrate further influence to the liver. We also analyzed the astrocyte activation in the brain by immunofluorescence (IF). Here, we show that the structure of the gut microbiome changes markedly after rats undergo CUMS. Notably, we found that the ratio of Lactobacillus to Clostridium can be a vital index for the development of depression. Depression-like behavior can be duplicated through FMT. Moreover, increased zonulin and fatty acid binding protein-2 indicates that gut barrier integrity is broken after FMT. Subsequently, metabolomics shows that liver metabolic disorder occurs and leads to liver coagulative necrosis. In addition, increased inflammatory cytokine expression and higher astrocyte activation indicate an inflammatory process in the brain. These findings suggest that dysbiosis gut microbiome contributes to development of depression and further causes liver metabolic disorders in a way that may be relevant to the Lactobacillus to Clostridium ratio.


Asunto(s)
Encéfalo/patología , Depresión/metabolismo , Inflamación/metabolismo , Hígado/metabolismo , Metabolómica/métodos , Estrés Psicológico/psicología , Animales , Enfermedad Crónica , Modelos Animales de Enfermedad , Microbioma Gastrointestinal , Humanos , Hígado/patología , Masculino , Ratas
9.
Oxid Med Cell Longev ; 2019: 8194804, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31341536

RESUMEN

Generally, inflammatory bowel disease (IBD) can be caused by psychology, genes, environment, and gut microbiota. Therefore, IBD therapy should be improved to utilize multiple strategies. Shen Ling Bai Zhu San (SLBZS) adheres to the aim of combating complex diseases from an integrative and holistic perspective, which is effective for IBD therapy. Herein, a systems pharmacology and microbiota approach was developed for these molecular mechanisms exemplified by SLBZS. First, by systematic absorption-distribution-metabolism-excretion (ADME) analysis, potential active compounds and their corresponding direct targets were retrieved. Then, the network relationships among the active compounds, targets, and disease were built to deduce the pharmacological actions of the drug. Finally, an "IBD pathway" consisting of several regulatory modules was proposed to dissect the therapeutic effects of SLBZS. In addition, the effects of SLBZS on gut microbiota were evaluated through analysis of the V3-V4 region and multivariate statistical methods. SLBZS significantly shifted the gut microbiota structure in a rat model. Taken together, we found that SLBZS has multidimensionality in the regulation of IBD-related physiological processes, which provides new sights into herbal medicine for the treatment of IBD.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Humanos , Microbiota
10.
Eur J Drug Metab Pharmacokinet ; 44(6): 771-776, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31087280

RESUMEN

BACKGROUND AND OBJECTIVES: Effective management of immunosuppressants is extemely important to improve prognosis of heart transplant recipients. We aim to investigate the effects of cytochrome P450 (CYP) 3A5 (rs776746) single nucleotide polymorphisms (SNPs) on serum tacrolimus concentrations/doses (C/Ds, ng/mL per mg/kg) and long-term prognosis in Chinese heart transplant recipients. METHODS: We detected the CYP3A5 SNPs of 203 consecutive Chinese heart transplant recipients between August 2005 and July 2012, and 55 of them who received tacrolimus-based immunosuppressive therapy were enrolled in this study. The tacrolimus C/Ds at 1, 3, 6, 12, 24 and 36 months after transplantation were routinely calculated. X-ray-guided endomyocardial biopsies (EMBs) were performed at 1, 3 and 6 months after heart transplantion to evaluate acute rejection degrees. All participants were then followed up annually until May 2018. The designed primary endpoint was all-cause mortality. RESULTS: In 55 heart transplant recipients (43 males and 12 females), CYP3A5 non-expressors (CYP3A5*3/*3, n = 40) had significantly higher tacrolimus C/Ds than expressors (CYP3A5*1/*3, n = 15) at all time points (P < 0.001). Chi-squared test showed no significant differences in EMB-proven acute rejections between the two groups within 6 months after heart transplantion. The median follow-up period was 94.7 months, and eight patients died. Kaplan-Meier analysis showed CYP3A5 expressors tend to have higher mortality than non-expressors (20% vs 12.5%, log-rank: P = 0.314). CONCLUSIONS: CYP3A5 SNPs affect tacrolimus pharmacokinetics in Chinese heart transplant recipients, and non-expressors have higher tacrolimus C/Ds. In addition, expressors tend to have a worse long-term prognosis than non-expressors.


Asunto(s)
Citocromo P-450 CYP3A/genética , Inmunosupresores/administración & dosificación , Inmunosupresores/sangre , Tacrolimus/administración & dosificación , Tacrolimus/sangre , Adulto , Pueblo Asiatico , Femenino , Genotipo , Trasplante de Corazón , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Pronóstico
11.
Plant Physiol ; 180(1): 276-288, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30737268

RESUMEN

The Arabidopsis (Arabidopsis thaliana) root epidermis is a simple model for investigating cell fate specification and pattern formation. In addition to regulatory networks consisting of transcription factors, histone deacetylases are also involved in the formation of cellular patterns. Here, we report thatHistone Deacetylase19 (HDA19) affects the root epidermal cellular pattern through regulation of cortical cell fate by interacting with SCARECROW (SCR). HDA19 binds to the DNA sequence upstream of SCR, as well as to those of several of SCR's target genes, and regulates their expression. Mutant lines of several SCR target genes show impaired patterns of epidermal differentiation and cortical cell division, similar to that of hda19 This work presents HDA19 and SCR as two further players in the regulation of cortical and epidermal cell specification and describes an additional function for SCR.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citología , Histona Desacetilasas/metabolismo , Raíces de Plantas/citología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Diferenciación Celular , Regulación de la Expresión Génica de las Plantas , Histona Desacetilasas/genética , Células Vegetales , Epidermis de la Planta/citología , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente
12.
Small ; 14(35): e1802045, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30084537

RESUMEN

In this research, bulk graphitic carbon nitride (g-C3 N4 ) is exfoliated and transferred to the carbon nitride nanosheets (CNNSs), which are then coupled with MIL-88B(Fe) to form the hybrid. From the results of the powder X-ray diffraction, scanning electronic microscopy and thermogravimetric analysis, it is found that the doping of CNNSs on the surface of MIL-88(Fe) could maintain the basic structure of MIL-88B(Fe), and the smaller dimension of CNNSs might influence the crystallization process of metal-organic frameworks (MOFs) compared to bulk g-C3 N4 . Besides, the effects of the CNNSs incorporation on photocatalysis are also investigated. Through the photoluminescence spectra, electrochemical measurements, and photocatalytic experiments, the hybrid containing 6% CNNSs is certified to possess the highest catalytic activity to degrade methylene blue and reduce Cr(VI) under visible light. The improvement of the photocatalytic performance can be attributed to the matched energy level which favors the formation of the heterojunctions. Besides, it promotes the charge migration such that the contact between MOFs and CNNSs is more intimate, which can be inferred from the electronic microscopy images. Finally, a possible photocatalytic mechanism is put forward by the relative calculation and the employment of the scavengers to trap the active species.

13.
Hepatol Int ; 12(3): 277-287, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29881991

RESUMEN

BACKGROUND: Plasma microRNA (miRNA) levels may be altered during pathological processes; therefore, they may potentially serve as biomarkers for the diagnosis and prognosis of human diseases. This study aimed to explore whether plasma miRNAs may serve as new biomarkers for liver injury among chronic hepatitis B (CHB) patients with normal or nearly normal alanine aminotransferase (ALT) levels. METHODS: Plasma miRNAs from each of three independent groups (no prominent liver injury and persistently normal ALT levels, NPNALT; significant liver injury with persistently normal ALT levels, SPNALT; and healthy) were profiled by miRNA microarray analysis. Differentially expressed miRNAs were then validated by a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. The area under the receiver operating characteristic (AUC) curve was used to analyze the candidate miRNAs validated by qRT-PCR for diagnostic accuracy. RESULTS: Twenty differentially expressed miRNAs were identified by microarray analysis. Seven miRNAs with elevated serum levels were validated by qRT-PCR analysis, and four of them were significantly different between the SPNALT and NPNALT groups. The AUCs of hsa-miR-122-5p and hsa-miR-151-3p were 0.877 (cutoff value = 13.38; 95% CI 0.792-0.963; sensitivity = 83.3%, specificity = 80%) and 0.882 (cutoff value = 7.4; 95% CI 0.797-0.966; sensitivity = 83.3%, specificity = 73.3%), respectively, indicating early liver injury. However, there was no significant correlation of miRNAs with either necroinflammation or fibrosis. CONCLUSION: Serum hsa-miR-122-5p and hsa-miR-151-3p may function as new biomarkers for liver injury in SPNALT patients. With these two biomarkers, we may be able to identify a subset of patients who are experiencing liver injury but have normal ALT levels for further evaluation with a biopsy procedure.


Asunto(s)
Alanina Transaminasa/metabolismo , Hepatitis B Crónica/diagnóstico , MicroARNs/metabolismo , Adulto , Biomarcadores/metabolismo , Femenino , Humanos , Cirrosis Hepática/diagnóstico , Masculino , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
14.
Exp Eye Res ; 169: 28-37, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29421327

RESUMEN

Our previous study has shown heme oxygenase-1 (HO-1) protects human lens epithelial cells (LECs) against H2O2-induced oxidative stress and apoptosis. Nrf2, the major regulator of HO-1, is triggered during the mutual induction of oxidative stress and ER stress. In response to ER stress, unfolded protein response (UPR) serves as a program of transcriptional and translational regulation mechanism with PERK involved. Both Nrf2 and ATF4 are activated as the downstream effect of PERK signaling coordinating the convergence of dual stresses. However, the ways in which Nrf2 interacting with ATF4 regulates deteriorated redox state have not yet been fully explored. Here, the transfected LECs with Nrf2 overexpression illustrated enhanced resistance in morphology and viability upon H2O2 treatment condition. Intracellular ROS accumulation arouses ER stress, initiating PERK dependent UPR and inducing the downstream signal Nrf2 and ATF4 auto-phosphorylation. Further, converging at target promoters, ATF4 facilitates Nrf2 with the expression of ARE-dependent phase II antioxidant and detoxification enzymes. According to either Nrf2 or ATF4 gene modification, our data suggests a novel interaction between Nrf2 and ATF4 under oxidative and ER stress, thus drives specific enzymatic and non-enzymatic reactions of antioxidant mechanisms maintaining redox homeostasis. Therapies that restoring Nrf2 or ATF4 expression might help to postpone LECs aging and age-related cataract formation.


Asunto(s)
Factor de Transcripción Activador 4/metabolismo , Estrés del Retículo Endoplásmico , Células Epiteliales/citología , Cristalino/citología , Factor 2 Relacionado con NF-E2/fisiología , Estrés Oxidativo , Western Blotting , Catalasa/metabolismo , Línea Celular , Citoprotección , Células Epiteliales/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente Indirecta , Glutatión/metabolismo , Humanos , Peróxido de Hidrógeno/toxicidad , Cristalino/metabolismo , Oxidantes/toxicidad , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Superóxido Dismutasa/metabolismo , Transfección , Respuesta de Proteína Desplegada/fisiología , eIF-2 Quinasa/metabolismo
15.
Environ Pollut ; 222: 323-330, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28024811

RESUMEN

The effects of salinity on metal toxicity are complex: not only affecting metal bioaccumulation, but also altering the physiology and sensitivity of organisms. In this study, we used a toxicokinetic-toxicodynamic (TK-TD) model to separate and quantify the dual effects of salinity on copper (Cu) toxicity in a euryhaline clam Potamocorbula laevis. The toxicokinetics of Cu was determined using the stable isotope 65Cu as a tracer at concentrations (10-500 µg L-1) realistic to contaminated environments and at salinities ranging from 5 to 30. At low Cu concentrations (ca. 10 µg L-1), Cu bioaccumulation decreased monotonically with salinity, and the uptake rate constant (ku, 0.546 L g-1 h-1 to 0.213 L g-1 h-1) fitted well with an empirical equation, ku = 1/(1.35 + 0.116·Salinity), by treating salinity as a pseudo-competitor. The median lethal concentrations (LC50s) of Cu were 269, 224, and 192 µg L-1 at salinity 5, 15, and 30, respectively. At high Cu concentrations (ca. 500 µg L-1), elevating salinity were much less effective in decreasing Cu bioaccumulation; whereas Cu toxicity increased with salinity. The increased toxicity could be explained by the increases in Cu killing rates (kks), which were estimated to be 0.44-2.08 mg µg-1 h-1 and were presumably due to the osmotic stress caused by the deviation from the optimal salinity of the clams. The other toxicodynamic parameter, internal threshold concentration (CIT), ranged from 79 to 133 µg-1 g-1 and showed no clear trend with salinity.


Asunto(s)
Bivalvos/efectos de los fármacos , Bivalvos/metabolismo , Cobre/farmacocinética , Cobre/toxicidad , Agua Dulce/química , Salinidad , Contaminantes Químicos del Agua/farmacocinética , Contaminantes Químicos del Agua/toxicidad , Animales , Ecotoxicología , Modelos Biológicos , Toxicocinética
16.
Plant Signal Behav ; 11(2): e1131373, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26689639

RESUMEN

The cellular patterning of Arabidopsis root epidermis is a well-characterized system for study of how single-layered cells are arranged in a particular spatial order. Previously, we found that histone acetylation plays an important role in regulating epidermal differentiation by relaying positional information. To investigate the underlying mechanisms, we screened all available mutants of both HDAC and HAT families. Analyses of mutants of HDAC family members revealed that among single mutants, only HDA6, HDA18 and HDA19 exhibited ectopic H cells at the N position. Similarly, among HAT family members, only single mutants for GCN5 and HAF2 exhibited altered epidermal phenotypes, which were unexpectedly similar to the phenotypes observed in HDAC mutants. Based on these results, together with the previous findings regarding the regulatory mechanisms of HDA18 and HDA6, we proposed that homeostasis of histone acetylation is important for robustness of the regulatory network responsible for the cellular patterning of the Arabidopsis root epidermis.


Asunto(s)
Proteínas de Arabidopsis/fisiología , Arabidopsis/enzimología , Histona Acetiltransferasas/fisiología , Histona Desacetilasas/fisiología , Acetilación , Arabidopsis/citología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Tipificación del Cuerpo , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Homeostasis
17.
Plant Physiol ; 168(4): 1448-58, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26143251

RESUMEN

Cellular patterning in the Arabidopsis (Arabidopsis thaliana) root epidermis is dependent on positional information, the transmission of which involves histone acetylation. Here, we report that HISTONE DEACETYLASE6 (HDA6) has significant effects on this cellular patterning. Mutation of HDA6 led to ectopic hair cells in the nonhair positions of root epidermis in Arabidopsis, based on an analysis of paraffin sections stained with Toluidine Blue. While HDA6 was present throughout the root tip, epidermis-specific complementation with HDA6 could rescue the hda6 phenotype. Both transcript levels and expression patterns of ENHANCER OF TRIPTYCHON AND CAPRICE1 (ETC1) and GLABRA2 (GL2) in the root tip were affected in hda6. Consistent with these changes in expression, HDA6 directly bound to the promoter regions of ETC1 and GL2, and acetylation of histone H3 on these promoter regions and acetylation of histone H4 on the ETC1 promoter region was increased in the hda6 mutant. Taken together, these results indicate that HDA6 affects the cellular patterning of Arabidopsis root epidermis through altering the histone acetylation status of ETC1 and GL2 promoters and thereby affects the expression of these two components of the core transcription factor network determining epidermal cell fates. Our findings thus provide new insights into the role of histone acetylation in root epidermis cell patterning.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Unión al ADN/genética , Histona Desacetilasas/genética , Proteínas de Homeodominio/genética , Mutación , Epidermis de la Planta/genética , Raíces de Plantas/genética , Acetilación , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Unión al ADN/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Histona Desacetilasas/metabolismo , Proteínas de Homeodominio/metabolismo , Microscopía Confocal , Epidermis de la Planta/metabolismo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Plantones/genética , Plantones/metabolismo
18.
Plant Cell ; 25(1): 257-69, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23362208

RESUMEN

The differentiation of hair (H) and non-hair (N) cells in the Arabidopsis thaliana root epidermis is dependent on positional relationships with underlying cortical cells. We previously found that histone acetylation relays positional information and that a mutant altered in the histone deacetylase gene family member HISTONE DEACETYLASE 18 (HDA18) exhibits altered H and N epidermal cell patterning. Here, we report that HDA18 has in vitro histone deacetylase activity and that both mutation and overexpression of HDA18 led to cells at the N position having H fate. The HDA18 protein physically interacted with histones related to a specific group of kinase genes, which are demonstrated in this study to be components of a positional information relay system. Both down- and upregulation of HDA18 increased transcription of the targeted kinase genes. Interestingly, the acetylation levels of histone 3 lysine 9 (H3K9), histone 3 lysine 14 (H3K14) and histone 3 lysine 18 (H3K18) at the kinase genes were differentially affected by down- or upregulation of HDA18, which explains why the transcription levels of the four HDA18-target kinase genes increased in all lines with altered HDA18 expression. Our results reveal the surprisingly complex mechanism by which HDA18 affects cellular patterning in Arabidopsis root epidermis.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Regulación de la Expresión Génica de las Plantas , Histona Desacetilasas/genética , Epidermis de la Planta/enzimología , Acetilación , Secuencia de Aminoácidos , Arabidopsis/citología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Diferenciación Celular , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulación hacia Abajo , Histona Desacetilasas/metabolismo , Histonas/genética , Histonas/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Fenotipo , Fosfotransferasas/genética , Fosfotransferasas/metabolismo , Epidermis de la Planta/citología , Epidermis de la Planta/genética , Raíces de Plantas/citología , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Procesamiento Proteico-Postraduccional , Activación Transcripcional , Regulación hacia Arriba
19.
Proc Natl Acad Sci U S A ; 108(30): 12539-44, 2011 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-21737749

RESUMEN

Jasmonate (JA) and ethylene (ET) are two major plant hormones that synergistically regulate plant development and tolerance to necrotrophic fungi. Both JA and ET induce the expression of several pathogenesis-related genes, while blocking either signaling pathway abolishes the induction of these genes by JA and ET alone or in combination. However, the molecular basis of JA/ET coaction and signaling interdependency is largely unknown. Here, we report that two Arabidopsis ET-stabilized transcription factors (EIN3 and EIL1) integrate ET and JA signaling in the regulation of gene expression, root development, and necrotrophic pathogen defense. Further studies reveal that JA enhances the transcriptional activity of EIN3/EIL1 by removal of JA-Zim domain (JAZ) proteins, which physically interact with and repress EIN3/EIL1. In addition, we find that JAZ proteins recruit an RPD3-type histone deacetylase (HDA6) as a corepressor that modulates histone acetylation, represses EIN3/EIL1-dependent transcription, and inhibits JA signaling. Our studies identify EIN3/EIL1 as a key integration node whose activation requires both JA and ET signaling, and illustrate transcriptional derepression as a common mechanism to integrate diverse signaling pathways in the regulation of plant development and defense.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Etilenos/metabolismo , Proteínas Nucleares/metabolismo , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Factores de Transcripción/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/microbiología , Proteínas de Arabidopsis/genética , Secuencia de Bases , Botrytis/patogenicidad , ADN de Plantas/genética , Proteínas de Unión al ADN , Histona Desacetilasas/metabolismo , Modelos Biológicos , Proteínas Nucleares/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Técnicas del Sistema de Dos Híbridos
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 30(10): 2237-41, 2010 Oct.
Artículo en Chino | MEDLINE | ID: mdl-20965813

RESUMEN

OBJECTIVE: To investigate the common resource of Chinese herbal medicine in western of Luoding City, Guangdong Province, and propose pertinent suggestions concerning the exploitation,utilization and conservation of the medicinal resources. METHODS: With plant taxonomy method, we selected the JiaYi town as the center for local common Chinese herbal medicine resources, ecological environment and non-governmental investigation of medicinal. RESULTS: There were 123 species of medicinal plants in Jiayi Town, including pteridophyte 11 species, gymnosperm 5 species, dicotyledon 97 species,and monocotyledon 12 species. CONCLUSION: This region has an excellent ecological environment and forest plant communities preserved relatively intact suitable for the growth of Lingnan Chinese herbal medicine, as well as a profound cultural background of folk medicine. The resources should be actively protected for further rational development and utilization.


Asunto(s)
Conservación de los Recursos Naturales , Medicamentos Herbarios Chinos , China
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