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1.
Org Lett ; 22(10): 4038-4042, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32379460

RESUMO

A nickel(II)-catalyzed addition of aryl-, alkenyl-, and alkylboronic acids to alkenylazaarenes was presented. This reaction exhibited high efficiency (up to 93% yield), a broad substrate scope (seven types of heterocycles), and good functional group compatibility. The resulting products can be further transformed to many useful building blocks. Finally, the preliminary studies suggested that the adjacent N atom of the heterocycles was essential for the high reactivity.

2.
Neurol India ; 68(2): 474-477, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32415028

RESUMO

Optic neuritis is an inflammatory demyelinating disorder of the central nervous system. Anti-NMDA receptor (NMDAR) antibodies encephalitis is also mediated by the inappropriate immunological response. We report a girl who was readmitted because of unilateral eye pain and vision impairment in the remission period of anti-NMDAR encephalitis. Based on the limited available literature on the treatment of optic neuritis associated with anti-NMDA receptor antibody, she was treated with a combination of corticosteroids and intravenous immunoglobulin with clinical improvement. Optic neuritis in the remission phase of anti-N-methyl-D-aspartate receptor encephalitis remains relatively uncommon. It is important to document and follow these patients to understand the pathogenesis of optic neuritis in the setting of anti-NMDAR encephalitis and formulate effective therapeutic strategies.

3.
Mikrochim Acta ; 187(6): 313, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32377952

RESUMO

A low-molecular-weight molecule (4-(2-(3-(dicyanomethyl)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl-benzoate, DDPB) has been developed. The organic framework possesses very weak fluorescence . The feasibility of the signal transduction has been performed via fluorometric titrations in solution. DDPB gives rise to responses to carboxylesterase 2 (CES2) based on "off-on" responses. The red emission at 670 nm has been derived from the enzyme-induced hydrolysis of ester linkages, thus suppressing the intramolecular charge transfer (ICT) effect and thereby generating the fluorescent segment. The optical excitation window for this probe is extended to the visible light range (λex = 516 nm), and it will induce less harmful influence on biological substances. The detection limit for the measurement of CES2 concentration is as low as 2.33 mU/mL. The conventional studies concerning the activation process are generally performed within only a single liveing cell system. In this study, it is the first time that expression of carboxylesterase 2 in five kinds of cell lines (HeLa > C1498 > active T cell > Jurkat > unactive T cell) has been clarified by flow cytometry, Western blotting, and confocal microscopy analysis. The elucidation of CES2 and its variability in a variety of cells will open new ways for drug metabolism and disease prevention. Graphical abstract We reported a new "substrate-mediated light-on" strategy based on an ester bond cleavage reaction. Most of prepared nanomaterials and organic fluorophores possessed short wavelength emissions in the blue or green region which will not be difficult for cellular imaging. In this study, a novel functional molecule (DDPB) was considered as the substrate for CES2 and the optical "off-on" response was realized. DDPB was cell permeable and possessed very low cytotoxicity. Moreover, the identification of CES2 and their subtle changes in five different cells afforded the sequence for carboxylesterase-2 as Hela > C1498 > Active T cell > Jurkat > Unactive T cell. Inhibition studies showed that the hydrolysis of DDPB was effectively suppressed by bis-p-nitrophenyl phosphate and the cellular tracking results firmly supported this point. To our knowledge, the inter-individual variability for the CES2 expressions in five different cell lines has never been reported via the substrate induced optical changes.

4.
BMC Pulm Med ; 20(1): 78, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228546

RESUMO

BACKGROUND: This study aimed to investigate the role of MIR17HG in non-small cell lung cancer (NSCLC). METHODS: Differential expression of MIR17HG in NSCLC was first detected by exploring the TCGA dataset. Expression levels of miR-142-3p in both NSCLC and non-tumor tissues were determined by qPCR. The effects of overexpressing MIR17HG on the methylation of miR-142 were assessed by MSP. The effects of overexpressing MIR17HG, miR-142-3p and Bach-1 on the invasion and migration of NSCLC cells were assessed by Trasnwell invasion or migration assay. RESULTS: Analysis of TCGA dataset revealed slightly downregulated expression of MIR17HG in NSCLC. This downregulation was further confirmed by measuring the expression levels of MIR17HG in NSCLC and non-tumor tissues from NSCLC patients. MIR17HG was found to decrease the methylation of miR-142-3p, and overexpression of MIR17HG led to upregulated miR-142-3p. Moreover, overexpression of MIR17HG also led to downregulated Bach-1, the downstream target of miR-142-3p. Cell invasion and migration analysis showed that overexpression of MIR17HG and miR-142-3p led to inhibited cancer cell invasion and migration. In contrast, overexpression of Bach-1 played an opposite role and attenuated the effects of overexpressing MIR17HG and miR-142-3p. CONCLUSION: MIR17HG inhibits NSCLC by upregulating miR-142-3p to downregulate Bach-1. TRIAL REGISTRATION: TJ-MU-2012-0148594, registered January 2, 2012.

5.
Zhongguo Fei Ai Za Zhi ; 23(5): 314-320, 2020 May 20.
Artigo em Chinês | MEDLINE | ID: mdl-32317090

RESUMO

BACKGROUND: The incidence and mortality of lung cancer often rank first in all malignant tumors. DNA methylation, as one of epigenetics, often participates in the development and progression of tumors. CDO1 as a tumor suppressor gene always undergoes methylation changes early in tumor development. Therefore, this study aims to discuss the value of CDO1 methylation in the early diagnosis of lung cancer. METHODS: Peripheral blood samples were collected from tumor patients and healthy people. Detection of the methylation level of CDO1 in plasma by sulfite modification and quantitative real-time PCR. RESULTS: The level of gene methylation in peripheral blood of lung cancer patients was significantly higher than that of benign lung disease patients and healthy people. The methylation level of CDO1 was significantly different in the stratified comparison of gender, lymph node metastasis and tumor-node-metastasis (TNM) stage (P<0.05). The sensitivity and specificity of CDO1 were 52.2% and 78.6%, respectively. The overall accuracy of the diagnosis was significantly higher than that of the clinical tumor markers, and the sensitivity of CDO1 to stage I and II patients was the highest (40.8%, 47.1%). In addition, CDO1 could effectively increase the sensitivity of diagnosis in multiple joint examinations. CONCLUSIONS: Detecting the methylation level of CDO1 has a potentially huge advantage for the early diagnosis of lung cancer.

6.
Sci Total Environ ; 721: 137807, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32179356

RESUMO

Biological nitrogen fixation (BNF) mediated by diazotrophic communities is a major source of bioavailable nitrogen in mangrove wetlands, which plays important roles in maintaining the health and stability of mangrove ecosystems. Recent large-scale mangrove afforestation activities have drawn great attention due to introduced mangrove species and their potential impacts on bio-functionalities of local ecosystems. However, the effects of introduced mangrove species on diazotrophic communities remain unclear. Here, we analyzed rhizosphere and endosphere diazotrophic communities between native mangrove species (Avicennia marina) and introduced mangrove species (Sonneratia apetala and Laguncularia racemose) by sequencing nifH gene amplicons. Our results showed that S. apetala and L. racemose introduction significantly (P < 0.05) increased nutrition components (e.g., total carbon and total nitrogen) in rhizosphere, as well as the diazotrophs richness in rhizosphere and endosphere. The relative abundance of clusters III diazotrophs in the rhizosphere and Rhizobium in the endosphere were significantly increased with L. racemosa or S. apetala introduction. Fe and pH were the main environmental factors driving the divergence of endophyte-rhizophyte diazotrophs between native and introduced mangroves. The correlation-based network analyses indicated that the interaction among rhizophyte-endophyte diazotrophs is more harmonious in native mangrove, while there exist more competition in introduced mangroves. These findings expand our current understanding of BNF in mangrove afforestation, and providing new perspectives to sustainable management of mangrove ecosystem.

7.
Brain Res ; 1737: 146802, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32220534

RESUMO

Growth differentiation factor 11 (GDF11), a member of the transforming growth factor-ß (TGF-ß) superfamily, regulates various biological processes in mammals. The effect of GDF11 in brain injury has not been fully elucidated. Our aim was to investigate the effects of GDF11 in cerebral ischemic injury. The expression level of GDF11 increased significantly in the peri-infarct cerebral cortex. Next, the effect of the intracerebroventricular injection of a GDF11 overexpression lentivirus or rGDF11 was investigated in middle cerebral artery occlusion (MCAO) rats. The preventative effects of the GDF11 overexpression virus on stroke were observed. The delivery of the lentivirus into rats before MCAO significantly reduced the infarct volume and the percentage of apoptotic cells and improved motor function in MCAO rats. Furthermore, it elevated the expression of p-Smad2/3 and promoted neurogenesis and angiogenesis in the ipsilateral SVZ during ischemic injury. More importantly, the therapeutic effects of rGDF11 on stroke were subsequently explored. The results in MCAO rats treated with rGDF11 were found similar to that in those treated with the GDF11 overexpression lentivirus. Together, these findings indicate that GDF11 has neuroprotective and neurorestorative effects in cerebral ischemic injury and provide new insights into the function and mechanism of GDF11 in stroke models.

8.
J Neurosci Methods ; 335: 108567, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32001295

RESUMO

BACKGROUND: Feature selection is a crucial step in the machine learning methods that are currently used to assist with decoding brain states from fMRI data. This step can be based on either feature discrimination or feature reliability, but there is no clear evidence indicating which method is more suitable for fMRI data. METHODS: We used ANOVA and Kendall's concordance coefficient as proxies for the two kinds of feature selection criteria. The performances of both methods were compared using different subject and feature numbers. The study included 987 subjects from the Human Connectome Project (HCP). RESULTS: Classification performance suggested that features based on discrimination were more capable of distinguishing between various brain states for any number of subjects or extracted features. In addition, reliability-based features were always more stable than other features, and these properties (discernment and stability) of features, to some degree, related to the number of subjects and features. Furthermore, when the number of extracted features increased, the feature distributions also gradually extended from occipital lobe to more association regions of the brain. CONCLUSION: The results from this study provide empirical guides for feature selection for the prediction of individual brain states.

9.
Bone Joint J ; 102-B(2): 177-185, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32009426

RESUMO

AIMS: To investigate the benefits of denosumab in combination with nerve-sparing surgery for treatment of sacral giant cell tumours (GCTs). METHODS: This is a retrospective cohort study of patients with GCT who presented between January 2011 and July 2017. Intralesional curettage was performed and patients treated from 2015 to 2017 also received denosumab therapy. The patients were divided into three groups: Cohort 1: control group (n = 36); cohort 2: adjuvant denosumab group (n = 9); and cohort 3: neo- and adjuvant-denosumab group (n = 17). RESULTS: There were 68 patients within the study period. Six patients were lost to follow-up. The mean follow-up was 47.7 months (SD 23.2). Preoperative denosumab was found to reduce intraoperative haemorrhage and was associated with shorter operating time for tumour volume > 200 cm3. A total of 17 patients (27.4%) developed local recurrence. The locoregional control rate was 77.8% (7/9) and 87.5% (14/16) respectively for cohorts 2 and 3, in comparison to 66.7% (24/36) of the control group. The recurrence-free survival (RFS) rate was significantly higher for adjuvant denosumab group versus those without adjuvant denosumab during the first two years: 100% vs 83.8% at one year and 95.0% vs 70.3% at two years. No significant difference was found for the three-year RFS rate. CONCLUSION: Preoperative denosumab therapy was found to reduce intraoperative haemorrhage and was associated with shorter operating times. Adjuvant denosumab was useful to prevent early recurrence during the first two years after surgery. Cite this article: Bone Joint J 2020;102-B(2):177-185.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Ósseas/cirurgia , Denosumab/uso terapêutico , Tumor de Células Gigantes do Osso/cirurgia , Sacro/cirurgia , Adolescente , Adulto , Neoplasias Ósseas/tratamento farmacológico , Criança , Terapia Combinada , Curetagem/métodos , Feminino , Tumor de Células Gigantes do Osso/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
10.
Int J Mol Sci ; 21(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32070035

RESUMO

Cadherin epidermal growth factor (EGF) laminin G (LAG) seven-pass G-type receptor 1 (CELSR1) is a member of a special subgroup of adhesion G protein-coupled receptors. Although Celsr1 has been reported to be a sensitive gene for stroke, the effect of CELSR1 in ischemic stroke is still not known. Here, we investigated the effect of CELSR1 on neuroprotection, neurogenesis and angiogenesis in middle cerebral artery occlusion (MCAO) rats. The mRNA expression of Celsr1 was upregulated in the subventricular zone (SVZ), hippocampus and ischemic penumbra after cerebral ischemic injury. Knocking down the expression of Celsr1 in the SVZ with a lentivirus significantly reduced the proliferation of neuroblasts, the number of CD31-positive cells, motor function and rat survival and increased cell apoptosis and the infarct volume in MCAO rats. In addition, the expression of p-PKC in the SVZ and peri-infarct tissue was downregulated after ischemia/ reperfusion. Meanwhile, in the dentate gyrus of the hippocampus, knocking down the expression of Celsr1 significantly reduced the proliferation of neuroblasts; however, it had no influence on motor function, cell apoptosis or angiogenesis. These data indicate that CELSR1 has a neuroprotective effect on cerebral ischemia injury by reducing cell apoptosis in the peri-infarct cerebral cortex and promoting neurogenesis and angiogenesis, mainly through the Wnt/PKC pathway.

11.
Zhongguo Fei Ai Za Zhi ; 23(2): 91-100, 2020 Feb 20.
Artigo em Chinês | MEDLINE | ID: mdl-32093453

RESUMO

Epigenetic modification is closely related to the occurrence and development of tumors. It mainly regulates gene function and expression level through DNA methylation, histone modification, regulation of non-coding RNA and chromatin structure reconstruction. At present, epigenetic drugs have been gradually applied to the treatment of malignant tumors. Common drug types include: DNA methyltransferase inhibitors and histone deacetylase inhibitors. However, these drugs still have many shortcomings and a wide range of clinical applications need further research. Encouragingly, the epigenetic drugs in combination with various anti-tumor drugs have shown great application potential. In this paper, we summarized the development mechanism of epigenetics in malignant tumors and the progress of related drugs.

12.
Molecules ; 25(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906574

RESUMO

Background: Dracocephalum peregrinum L., a traditional Kazakh medicine, has good expectorant, anti-cough, and to some degree, anti-asthmatic effects. Diosmetin (3',5,7-trihydroxy-4'-methoxyflavone), a natural flavonoid found in traditional Chinese herbs, is the main flavonoid in D. peregrinum L. and has been used in various medicinal products because of its anticancer, antimicrobial, antioxidant, estrogenic, and anti-inflammatory effects. The present study aimed to investigate the effects of diosmetin on the proliferation, invasion, and migration of glioma cells, as well as the possible underlying mechanisms. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), scratch wound, and Transwell assays were used to demonstrate the effects of diosmetin in glioma. Protein levels of Bcl-2, Bax, cleaved caspase-3, transforming growth factor-ß (TGF-ß), E-cadherin, and phosphorylated and unphosphorylated smad2 and smad3 were determined by Western blots. U251 glioma cell development and progression were measured in vivo in a mouse model. Results: Diosmetin inhibited U251 cell proliferation, migration, and invasion in vitro, the TGF-ß signaling pathway, and Bcl-2 expression. In contrast, there was a significant increase in E-cadherin, Bax, and cleaved caspase-3 expression. Furthermore, it effectively reduced the tumorigenicity of glioma cells and promoted apoptosis in vivo. Conclusion: The results of this study suggest that diosmetin suppresses the growth of glioma cells in vitro and in vivo, possibly by activating E-cadherin expression and inhibiting the TGF-ß signaling pathway.

13.
J Phys Condens Matter ; 32(18): 184001, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31918417

RESUMO

Singlet fission (SF) is a photophysical process considered as a possible scheme to bypass the Shockley-Queisser limit by generating two triplet-state excitons from one high-energy photon. Polyacene crystals, such as tetracene and pentacene, have shown outstanding SF performance both theoretically and experimentally. However, their instability prevents them from being utilized in SF-based photovoltaic devices. In search of practical SF chromophores, we use many-body perturbation theory within the GW approximation and Bethe-Salpeter equation to study the excitonic properties of a family of pyrene-stabilized acenes. We propose a criterion to define the convergence of exciton wave-functions with respect to the fine k-point grid used in the BerkeleyGW code. An open-source Python code is presented to perform exciton wave-function convergence checks and streamline the double Bader analysis of exciton character. We find that the singlet excitons in pyrene-stabilized acenes have a higher degree of charge transfer character than in the corresponding acenes. The pyrene-fused tetracene and pentacene derivatives exhibit comparable excitation energies to their corresponding acenes, making them potential SF candidates. The pyrene-stabilized anthracene derivative is considered as a possible candidate for triplet-triplet annihilation because it yields a lower SF driving force than anthracene.

14.
Phytopathology ; 110(2): 309-316, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31556343

RESUMO

Rice yield is greatly reduced owing to rice blast, a polycyclic fungal disease caused by the ascomycete Magnaporthe oryzae. Previously, Bacillus cereus HS24, isolated from a rice farm, showed a strong antimicrobial effect toward M. oryzae. To better exploit it as a biocontrol agent, HS24 was studied for the mechanism that it uses to suppress rice blast. Conidium germination in M. oryzae was significantly inhibited by HS24, whereby inhibition reached 97.8% at the concentration of 107 CFU/ml. The transcription levels of Ca2+/calmodulin-dependent protein kinase II, PMC1, and CCH1, key genes involved in the M. oryzae Ca2+ signaling pathway, were significantly decreased in HS24-treated conidia at high concentration. The treatment of M. oryzae with the corresponding Ca2+ signaling pathway inhibitors KN-93, verapamil, and cyclopiazonic acid significantly reduced conidium germination. This inhibitory effect was found to be concentration dependent, similar to the HS24 treatment. We also found that HS24 was able to decrease the intracellular free Ca2+ concentration in M. oryzae conidia significantly. The addition of exogenous Ca2+ did not diminish the inhibitory effect of HS24 on the reduction of intracellular free Ca2+ concentration and the level of conidium germination. In conclusion, B. cereus HS24 at high concentration prevents extracellular Ca2+ from entering the conidia in M. oryzae, causes a significant reduction of intracellular free Ca2+ concentration, and results in the inhibition of conidium germination.


Assuntos
Magnaporthe , Oryza , Bacillus cereus , Sinalização do Cálcio , Proteínas Fúngicas , Doenças das Plantas , Esporos Fúngicos
15.
Sci Total Environ ; 708: 134479, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31796288

RESUMO

The pollution of hexavalent chromium (Cr(VI)) in soil is a serious environmental issue. Herein, nanoscale zero-valent iron (NZVI) supported on rice husk-derived biochar (RBC) was employed as an efficient remediation material to minimize the harm of Cr(VI) in soil. A one-step carbothermal reduction method was used instead of the conventional wet chemistry method for material preparation in this study. Rice husk, an agricultural waste, was adopted as the carbon source (reductant) and support for nanometal synthesis simultaneously, so that the NZVI could be in-situ generated on the acquired biochar during the pyrolysis process. By pyrolyzing at 800 °C, the obtained biochar-supported nanoscale zerovalent iron (NZVI-RBC) exhibited high thermal stability and oxidation resistance. In the treatment of contaminated soil, the Cr(VI) no longer leached out from the soil after a complete removal of Cr(VI) (62.4 mg/L) from soil leachate in 120 min when the used NZVI-RBC dosage was above 8% of the soil in weight. This long-term remediation effect of NZVI-RBC may be related to the electron shuttle function of biochar. Furthermore, the bioavailability of Cr in the contaminated soil was significantly decreased. The present study provided a simple, feasible, and sustainable alternative to make full use of the agricultural waste resource to synthesize composite remediation agent containing NZVI and remediate Cr(VI) contaminated groundwater and soil.

16.
Sci Data ; 6(1): 295, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784528

RESUMO

The data presented here are related to the studyforrest project that uses the movie 'Forrest Gump' to map brain functions in a real-life context using functional magnetic resonance imaging (fMRI). However, neural-related fMRI signals are often small and confounded by various noise sources (i.e., artifacts) that makes searching for the signals induced by specific cognitive processes significantly challenging. To make neural-related signals stand out from the noise, the audio-visual movie watching fMRI dataset from the project was denoised by a combination of spatial independent component analysis and manual identification of signals or noise. Here, both the denoised data and the labeled decomposed components are shared to facilitate further study. Compared with the original data, the denoised data showed a substantial improvement in the temporal signal-to-noise ratio and provided a higher sensitivity in subsequent analyses such as in an inter-subject correlation analysis.

17.
Mar Biotechnol (NY) ; 21(5): 613, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31385167

RESUMO

The original version of this article unfortunately contained a mistake in the authorgroup section. Letters A, B, C, D, E and F were inadvertently added before each author's name. The original article has been corrected.

18.
Artif Cells Nanomed Biotechnol ; 47(1): 3400-3409, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401873

RESUMO

To grab the possible impact of lncRNA-SVUGP2 in the biology and process of non-small cell lung cancer (NSCLC). Sixty paired NSCLC tumour and the adjacent non-tumour lung tissues were collected for detection of lncRNA-SVUGP2. lncRNA-SVUGP2 expression in NSCLC cells (SK-MES-1, A549, SPC-A1, and NCI-H1975) was also detected. lncRNA-SVUGP2 was overexpressed and depressed in A549 and H1975 cells, and the effects of lncRNA-SVUGP2 dysregulation on cell biological performances including viability, colony formation, apoptosis, migration and invasion were grabbed. Furthermore, the regulatory association of lncRNA-SVUGP2 vs. EZH2 in H1975 cells, as well as the association between lncRNA-SVUGP2 and Wnt/ß-catenin pathway, was explored. lncRNA-SVUGP2 was depressed in NSCLC tissues and cells. Overexpression of lncRNA-SVUGP2 depressed proliferation, induced apoptosis, and suppressed migration and invasion of A549 and H1975 cells. In addition, lncRNA-SVUGP2 was repressed by EZH2 and was inversely correlated with EZH2 levels in H1975 cells. Repression of lncRNA-SVUGP2 potentially participated in the oncogenic function of EZH2. Besides, overexpression of lncRNA-SVUGP2 depressed the briskness of Wnt/ß-catenin signal in H1975 cells. Our data reveal that lncRNA-SVUGP2 is under-expressed in NSCLC cells and the reduced expression of lncRNA-SVUGP2 may enhance the development and process of NSCLC by interacting with EZH2 and activating Wnt/ß-catenin pathway.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Neoplasias Pulmonares/patologia , RNA Longo não Codificante/genética , Via de Sinalização Wnt/genética , Apoptose/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica/genética
19.
ACS Omega ; 4(6): 9813-9822, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31460071

RESUMO

The effects of particle size, temperature, and leaching time on the leaching behavior of rare-earth elements were studied. The leaching efficiency of the rare earth reached 39.24% under leaching conditions of hydrochloric acid concentration of 8.00 mol/L, particle size 95% distributed below 1.5 µm, leaching time of 120 min, and temperature of 90 °C. According to the scanning electron microscopy and X-ray diffraction analysis of the residue, the mechanism of the leaching process was also investigated. Actually, the phase of REFCO3 transformed into that of RECl3 and REF3 but there was an existing intermediate transition, where the phase of REFCO3 on reacting with hydrochloric acid generated that of REO x F3-2x and this process also released RE3+ into the solution. REO x F3-2x continued reacting with hydrochloric acid to release a lot of F-, which on combining with RE3+ formed REF3 precipitation. The leaching kinetics of rare earths follows a shrinking core model that can be expressed as 1 - 3(1 - x)2/3 + 2(1 - x) = k 1 t. The activation energies are 62.1, 54.8, 35.1, and 34.9 kJ/mol, respectively.

20.
Mar Biotechnol (NY) ; 21(5): 596-612, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31165295

RESUMO

Crassostrea ariakensis naturally distributes in the intertidal and estuary region with relative low salinity ranging from 10 to 25‰. To understand the adaptive capacity of oysters to salinity stress, we conducted transcriptome analysis to investigate the metabolic pathways of salinity stress effectors in oysters from two different geographical sites, namely at salinities of 16, 23, and 30‰. We completed transcriptome sequencing of 18 samples and a total of 52,392 unigenes were obtained after assembly. Differentially expressed gene (DEG) analysis and weighted gene correlation network analysis (WGCNA) were performed using RNA-Seq transcriptomic data from eye-spot larvae at different salinities and from different populations. The results showed that at moderately high salinities (23 and 30‰), genes related to osmotic agents, oxidation-reduction processes, and related regulatory networks of complex transcriptional regulation and signal transduction pathways dominated to counteract the salinity stress. Moreover, there were adaptive differences in salinity response mechanisms, especially at high salinity, in oyster larvae from different populations. These results provide a framework for understanding the interactions of multiple pathways at the system level and for elucidating the complex cellular processes involved in responding to osmotic stress and maintaining growth. Furthermore, the results facilitate further research into the biological processes underlying physiological adaptations to hypertonic stress in marine invertebrates and provide a molecular basis for our subsequent search for high salinity-tolerant populations.


Assuntos
Crassostrea/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Transcriptoma , Animais , Crassostrea/genética , Crassostrea/crescimento & desenvolvimento , Estuários , Perfilação da Expressão Gênica , Biblioteca Gênica , Ontologia Genética , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Anotação de Sequência Molecular , Pressão Osmótica , Oxirredução , Análise de Componente Principal , Salinidade , Transdução de Sinais
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