Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.425
Filtrar
1.
Carbohydr Polym ; 227: 115332, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590887

RESUMO

Advanced oxidation processes (AOPs) based on activated persulfate have received extensive attention for sludge pretreatment. Persulfate (PS) is a persistent oxidant and the excess persulfate in the sludge affects the carbohydrate analysis using the traditional phenol-sulfuric acid method. In this study, an improved phenol-sulfuric acid method was developed for the determination of carbohydrates in the presence of persulfate, and a critical procedure was introduced before the conventional determination with the assistance of the chemical pretreatments. The best reagent was screened from four reductants (i.e. Na2S, KI, Na2SO3 and Na2S2O3) and two free-radical scavengers (i.e. phenol and benzoic), and the optimal conditions were determined based on the monosaccharides (i.e. glucose, galactose and mannose) and the polysaccharides in different EPS fractions from two activated sludges. The results showed that Na2SO3 was the best reagent for chemical pretreatment due to redox reaction, high selectivity and colorless oxidation product, and the others were not suitable as pretreatment reagents mainly since the reaction products affect the final spectral analysis. Besides, the optimal Na2SO3 concentration for eliminating the impact of PS was 150 mmol/L, and the relative deviation of measurement is less than 5% if the PS concentration was on more than 100 mmol/L, regardless of the kinds of carbohydrates. Compared with the anthrone-sulfuric acid method and the sulfuric method, the improved phenol-sulfuric acid method has a great advantage for determining the carbohydrate concentration in the presence of PS.

2.
Insect Sci ; 27(1): 14-21, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31246335

RESUMO

Manipulating an exogenous or endogenous gene of interest at a defined level is critical for a wide variety of experiments. The Gal4/UAS system has been widely used to direct gene expression for studying complex genetic and biological problems in Drosophila melanogaster and other model organisms. Driven by a given tissue-specific Gal4, expressing UAS-transgene or UAS-RNAi (RNA interference) could be used to up- or down-regulate target gene expression, respectively. However, the efficiency of the Gal4/UAS system is roughly predefined by properties of transposon vector constructs and the insertion site in the transgenic stock. Here, we describe a simple way to modulate optomotor blind (omb) expression levels in its endogenous expression region of the wing disc. We co-expressed UAS-omb and UAS-omb-RNAi together under the control of dpp-Gal4 driver which is expressed in the omb expression region of the wing pouch. The repression effect is more sensitive to temperature than that of overexpression. At low temperature, overexpression plays a dominant role but the efficiency is attenuated by UAS-omb-RNAi. In contrast, at high temperature RNAi predominates in gene expression regulation. By this strategy, we could manipulate omb expression levels at a moderate level. It allows us to manipulate omb expression levels in the same tissue between overexpression and repression at different stages by temperature control.

3.
IEEE Trans Vis Comput Graph ; 26(1): 729-738, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31442987

RESUMO

We present a non-uniform recursive sampling technique for multi-class scatterplots, with the specific goal of faithfully presenting relative data and class densities, while preserving major outliers in the plots. Our technique is based on a customized binary kd-tree, in which leaf nodes are created by recursively subdividing the underlying multi-class density map. By backtracking, we merge leaf nodes until they encompass points of all classes for our subsequently applied outlier-aware multi-class sampling strategy. A quantitative evaluation shows that our approach can better preserve outliers and at the same time relative densities in multi-class scatterplots compared to the previous approaches, several case studies demonstrate the effectiveness of our approach in exploring complex and real world data.

4.
IEEE Trans Vis Comput Graph ; 26(1): 991-1000, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31443014

RESUMO

We present a new technique to enable the creation of shape-bounded Wordles, we call ShapeWordle, in which we fit words to form a given shape. To guide word placement within a shape, we extend the traditional Archimedean spirals to be shape-aware by formulating the spirals in a differential form using the distance field of the shape. To handle non-convex shapes, we introduce a multi-centric Wordle layout method that segments the shape into parts for our shape-aware spirals to adaptively fill the space and generate word placements. In addition, we offer a set of editing interactions to facilitate the creation of semantically-meaningful Wordles. Lastly, we present three evaluations: a comprehensive comparison of our results against the state-of-the-art technique (WordArt), case studies with 14 users, and a gallery to showcase the coverage of our technique.

5.
J Colloid Interface Sci ; 559: 105-114, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31614315

RESUMO

Exploring highly-efficient, low-cost and earth-abundant bi-functional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have a key role in economical overall water-splitting. Herein, a facile and general route is developed to prepare various non-noble metal-based electrocatalysts via NH3⋅H2O treatment (NT) on Ni foam (NF) (M-NT/NF, M = Co, Ni, Fe, Mn, Cu). The morphology and compositions of the obtained catalysts could be tuned via solvothermal process with NH3⋅H2O, and then optimizing the active sites exposure and effectively change the reaction kinetics of the electrocatalytic reaction. Moreover, the substrate of Ni foam is in favor of electrolyte transfer and release of produced gases. Then, the obtain Co-NT/NF, composed of metallic Co and Co(OH)2, exhibits excellent catalytic performance for HER with low overpotential of 178 mV@10 mA cm-2 and small Tafel slope of 75 mV dec-1, which is rarely reported for HER. For OER, only a low overpotential of 226 mV is required to deliver 10 mA cm-2 with a small Tafel slope of 46 mV dec-1. Moreover, the reported electrocatalysts present negligible current density loss during long-term stability measurement, demonstrating robust nanostructure feature of the prepared catalysts. This work opens a facile and efficient avenue to design bi-funtional electrocatalyst coupling with outstanding catalytic performance.

6.
J Phys Condens Matter ; 32(3): 034001, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31639105

RESUMO

The addition of various dipolar molecules is shown to affect the temperature dependence of the spin state occupancy of the much studied spin crossover Fe(II) complex, [Fe{H2B(pz)2}2(bipy)] (pz = pyrazol-1-yl, bipy = 2,2'-bipyridine). Specifically, the addition of benzimidazole results in a re-entrant spin crossover transition, i.e. the spin state starts in the mostly low spin state, then high spin state occupancy increases, and finally the high spin state occupancy decreases with increasing temperature. This behavior contrasts with that observed when the highly polar p -benzoquinonemonoimine zwitterion C6H2(…NH2)2(…O)2 was mixed with [Fe{H2B(pz)2}2(bipy)], which resulted in locking [Fe{H2B(pz)2}2(bipy)] largely into a low spin state while addition of the ethyl derivative C6H2(…NHC2H5)2(…O)2 did not appear to perturb the spin crossover transition of [Fe{H2B(pz)2}2(bipy)].

7.
J Nanosci Nanotechnol ; 20(6): 3604-3609, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748058

RESUMO

Chlorinated aromatic compounds (CACs) are a class of persistent organic pollutants, which have serious damage to water environment due to their own stable structure. But a good many of CACs were abandoned because of their tremendous yields and wide applications, so it is urgent to find the effective degradation methods for CACs. The electrochemical method is supposed to be a simple, environmentally friendly and effective pathway to degrade CACs. In this paper, a Pd/GO/Cu composite electrode was prepared by a combination of impregnation method and constant current electrodeposition method, which showed good electrochemical degradation efficiency for the 2,4-dichlorophenol. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface structure, functional group composition, crystal structure and surface element valence of the electrode. Moreover, the stability of the electrode was investigated, and the preparation conditions of the electrode were optimized.

8.
Magn Reson Imaging ; 65: 146-154, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726211

RESUMO

In magnetic resonance fingerprinting (MRF), tissue parameters are determined by finding the best-match to the acquired MR signal from a predefined signal dictionary. This dictionary searching (DS) process is generally performed in an exhaustive manner, which requires a large predefined dictionary and long searching time. A fast MRF DS algorithm, MRF-ZOOM, was recently proposed based on DS objective function optimization. As a proof-of-concept study, MRF-ZOOM was only tested with one of the earliest MRF sequences but not with the recently more popular unbalanced steady state free precession MRF sequence (MRF-ubSSFP, or MRF-FISP). Meanwhile noise effects on MRF and MRF-ZOOM have not been examined. The purpose of this study was to address these open questions and to verify whether MRF-ZOOM can be combined with a dictionary-compression based method to gain further speed. Numerical simulations were performed to evaluate the DS objective function properties, noise effects on MRF, and to compare MRF-ZOOM with other methods in terms of speed and accuracy. In-vivo experiments were performed as well. Evaluation results showed that premises of MRF-ZOOM held for MRF-FISP; noise did not affect MRF-ZOOM more than the conventional MRF method; when SNR ≥ 1, MRF quantification yielded accurate results. Dictionary compression introduced quantification errors more to T2 quantification. MRF-ZOOM was thousands of times faster than the conventional MRF method. Combining MRF-ZOOM with dictionary compression showed no benefit in terms of fitting speed. In conclusion, MRF-ZOOM is valid for MRF- FISP, and can remarkably save MRF dictionary generation and searching time without sacrificing matching accuracy.

9.
Mater Sci Eng C Mater Biol Appl ; 106: 110171, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753378

RESUMO

To developing a multiple cancer types targeting drug delivery carrier system, a 28 amino acids from the VAR2CSA was synthesized as the placental CSA-binding peptide (plCSA-BP). Its specific binding ability to cancer cells was tested on cancer tissue array, and the results showed that plCSA-BP could bind to multiple cancer types. Then, the plCSA-BP was used as a guiding peptide to coat nanoparticles synthesized from N-2-HACC (CSA/HACC-NPs) which were loaded with prodigiosin (CSA/HACC-PNPs) or indocyanine green (CSA/HACC-INPs). The cancer cells specific targeting and efficacy of the CSA/HACC-PNPs were tested by different cancer cells in vitro and various cancer xenograft model in vivo. A scramble peptide (SCR) was used as control and synthesized SCR/HACC-PNPs and SCR/HACC-INPs. The results showed that the CSA/HACC-INPs could specifically uptake by JEG-3, PC3 and A594 cells, and the CSA/HACC-PNPs exhibited better anti-cancer activity and lower toxic effect in subcutaneous choriocarcinoma and prostatic tumor models compared with the free prodigiosin, HACC-PNPs and SCR/HACC-PNPs. So, the CSA/HACC-NPs could be used as a specific delivery carrier for multiple cancer types, and provided an alternate treatment option of various cancers with a single recipe.

10.
Food Microbiol ; 86: 103340, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703864

RESUMO

Red sufu is a traditional food produced by the fermentation of soybean. In this study, sufu samples were periodically collected during the whole fermentation to investigate the dynamic changes of fungal and bacterial communities using high-throughput sequencing technology. The overall process can be divided into pre- and post-fermentation. During post-fermentation, the pH value showed a gradual decrease over time while the amino nitrogen content increased. Trichosporon, Actinomucor and Cryptococcus were the main genera in pre-fermentation while Monascus and Aspergillus were dominant in post-fermentation. This huge shift in fungal composition was caused by process procedure of pouring dressing mixture. However, the bacterial composition was not greatly changed after pouring dressing mixture, the Acinetobacter and Enterobacter were the predominant genera throughout the whole process. Furthermore, Bacillus species were first detected after adding dressing mixture, but declined abruptly to a very low level (0.07%) by the end of the fermentation. Our work demonstrates the dynamic changes of physicochemical properties and microbial composition in every fermentation stage, the knowledge of which could potentially serve as a foundation for improving the safety and quality of sufu in the future.

11.
J Cell Biochem ; 121(1): 755-767, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31478223

RESUMO

Glioblastoma (GBM) has become the most aggressive primary brain tumor in the world. Patients with GBM usually have a poor prognosis. The median survival times of GBM patients retain less than 2 years. Thus, it is urgent to investigate the molecular mechanism of GBM. Recently, studies have demonstrated that transcription factors (TFs) participate in cancer pathology by regulating long noncoding RNAs (lncRNAs). However, the functional and regulatory roles of TF-lncRNA crosstalks are still unclear. In this study, we constructed a global lncRNA-TF network (GLTN) based on competing endogenous RNA. As a result, some topological features of GLTN were identified. A known GBM lncRNA MCM3AP-AS1 showed multiple central topological features in GLTN. Furthermore, we identified hub genes and extracted the hub-hub pairs from GLTN to form a hub associated lncRNA-TF network (HALTN). Results showed that a risk model combined with multiple hubs had a significant effect on prognosis. Additionally, we performed module searching and two functional modules from HALTN were identified, which were confirmed as risk factors of GBM. More importantly, we also identified some core lncRNA-TF crosstalks that might form feedback loops to control the biological processes in GBM. Our results demonstrated that the synergistic, competitive lncRNA-TF crosstalks played an important role in pathological processes of GBM, and had strong effect on prognosis. All these results can help us to uncover the molecular mechanism and provide a new therapeutic target for GBM.

12.
Pharmacology ; : 1-9, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31671428

RESUMO

OBJECTIVES: Sepsis-induced inflammation injury and oxidative stress are well known causes of mortality. The anti-inflammatory effects of baicalin have been proposed in a mouse model of experimental sepsis. Here, we investigated its protective effects and associated mechanisms with respect to lipopolysaccharide (LPS)-induced injury in Caenorhabditis elegans. METHODS: Worms were stimulated by LPS (100 µg/mL), with baicalin (1, 10, 100 µmol/L), for 24 h. Animal survival rates and behaviors (reversal and omega turn) were then determined. Further, levels of the inflammatory cytokines interleukin 6 (IL-6), IL-1, and tumor necrosis factor (TNF)-α were detected by enzyme-linked immunosorbent assay. Western blotting was also performed to determine the protein expression levels of Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), Bax, and Bcl-2. The activities of malondialdehyde (MDA) and superoxide dismutase (SOD) contents were determined using corresponding kits. RESULTS: Baicalin (10, 100 µmol/L) improved LPS-stimulated C. elegans survival and rescued behavioral phenotypes. It also suppressed the oxidative stress related to LPS injury by decreasing MDA levels and increasing SOD activity. Moreover, the inflammatory response was inhibited as evidenced by decreased levels of cytokines including IL-6, IL-1, and TNF-α. In addition, baicalin treatment significantly decreased cleaved Bax levels and increased Bcl-2 expression in C. elegans treated with LPS. Simultaneously, the expression of NF-κB and TLR4 was significantly decreased. CONCLUSION: Baicalin treatment protects against LPS-induced injury by decreasing oxidative stress, repressing the inflammatory cascade, and inhibiting apoptosis.

13.
Medicine (Baltimore) ; 98(45): e17583, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702614

RESUMO

BACKGROUND: Long noncoding RNA paternally expressed 10 (lncRNA PEG10) is highly expressed in a variety of human cancers and related to the clinical prognosis of patients. However, to date there has been no previous study evaluating the prognostic significance of lncRNA PEG10 in gliomas. In the present study, we investigated the expression levels of lncRNA PEG10 to determine the prognostic value of this oncogene in human gliomas. METHODS: Expression levels of lncRNA PEG10 were detected by real-time polymerase chain reaction in a hospital-based study cohort of 147 glioma patients and 23 cases of patients with craniocerebral trauma tissues. Associations of lncRNA PEG10 expression with clinicopathological variables and clinical outcome of glioma patients were investigated. RESULTS: The results indicated that expression levels of lncRNA PEG10 were significantly increased in human gliomas compared to normal control brain tissues. In addition, lncRNA PEG10 expression was progressively increased from pathologic grade I to IV (P = .009) and correlated with the Karnofsky performance status (P = .018) in glioma patients. Furthermore, we also found that glioma patients with increased expression of lncRNA PEG10 had a higher risk to relapse and a statistically significant shorter overall survival (OS) than patients with reduced expression of lncRNA PEG10. In multivariate analysis, expression level of lncRNA PEG10 was found to be an independent prognostic factor for both progression-free survival and OS in glioma patients. CONCLUSIONS: LncRNA PEG10 served as an oncogene and played crucial roles in the progression of glioma. Molecular therapy targeted on lncRNA PEG10 might bring significant benefits to the clinical outcome of malignant glioma.


Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , RNA Longo não Codificante/genética , Regulação para Cima , Adulto , Idoso , Neoplasias Encefálicas/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Prognóstico , Análise de Sobrevida , Adulto Jovem
14.
Medicine (Baltimore) ; 98(45): e17852, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702645

RESUMO

RATIONALE: Fusidic acid (FA) is an active agent against gram-positive bacteria such as Staphylococcus, it is generally well tolerated and the major adverse effects are mild gastrointestinal discomfort, diarrhea, and headache. However, some rare side effects such as granulocytopenia and thrombocytopenia have also been reported. Here we report a case of FA-induced hepatotoxicity and hematologic toxicity. PATIENT CONCERNS: A 54-year-old woman with hepatitis B cirrhosis was referred to us because of fever, Staphylococcus aureus was identified in the twice blood culture, and intravenous FA was given (0.5 g, q8 hours). Twelve days after FA therapy, she developed nausea and jaundice. Meanwhile, complete blood cell count showed neutropenia (white blood cell count of 1360/µL, neutrophil of 619/µL) and aggravated thrombocytopenia (platelet count of 18,000/µL). Adverse drug reaction was suspected, and FA was stopped immediately, after 1 day of discontinuation of FA, nose bleeding occurred and the platelet count declined further and reached the lowest value of 4000/µL. DIAGNOSES: Hepatotoxicity and hematologic complications induced by FA were diagnosed. INTERVENTIONS AND OUTCOMES: The FA was stopped immediately, and concentrated platelet transfusion was used. Five days after withdrawal of FA, jaundice resolved and the hematologic index returned to the level before the medication. LESSONS: Hematologic adverse effect accompanying with hepatotoxicity may be induced by FA. Though the risk is rather low, it should not be overlooked.


Assuntos
Ácido Fusídico/administração & dosagem , Icterícia/induzido quimicamente , Neutropenia/induzido quimicamente , Infecções Estafilocócicas/tratamento farmacológico , Administração Intravenosa , Feminino , Ácido Fusídico/efeitos adversos , Hepatite B/complicações , Humanos , Cirrose Hepática/virologia , Pessoa de Meia-Idade , Neutropenia/terapia , Transfusão de Plaquetas , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/isolamento & purificação , Resultado do Tratamento
15.
ACS Appl Mater Interfaces ; 11(47): 44118-44123, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31682102

RESUMO

Activity and immobilization of catalysts in liquid-phase reactions seem not to coexist. We report here the excellent activity of an MoOx nanoparticle (NP) catalyst for d-glucose epimerization to d-mannose and the electrical immobilization of NPs in a flow reaction. Prior to that, a green and one-pot method to synthesize the MoOx NPs (3.05 nm) via oxidizing metal Mo by hydrogen peroxide was presented. The NPs overwhelmed the reported catalysts including epimerase for d-glucose epimerization, originating from a strong interaction between the NPs and the reactant that was demonstrated by ex situ and in situ characterizations and theoretical calculations. The electrically charged feature of NPs inspired us to find a convenient way to "immobilize" them inside an activated carbon bed, and thereby, a flow reactor was assembled. The continuous epimerization was run under 24 V for 16 days with an almost unchanged activity, and only 3.2% of total Mo was lost.

16.
Brain Res Bull ; 154: 127-134, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31756422

RESUMO

Patients with temporal lobe epilepsy (TLE) frequently suffer from memory disorders, and the pathological changes show widespread regional impairments in the brain. In lithium-pilocarpine (LIP)-treated rats with TLE, an abnormal hippocampal microstructure and functional connectivity have been observed. However, changes in other brain regions are still unclear. In the present study, diffusion tensor imaging and functional magnetic resonance imaging (MRI) signals were collected in LIP-TLE rats and controls using a 7.0 T MRI. Microstructural parameters and functional connectivity were calculated among regions of interest (ROIs), including the bilateral prefrontal cortex, amygdala, hippocampus and entorhinal cortex. A correlation analysis was further performed between the neuroimaging results and the behavioral performance in the novel object and novel location memory tests. In our results, TLE rats showed increased fractional anisotropy (FA) values in the hippocampus and decreased FA values in the amygdala and entorhinal cortex. In addition, decreased functional connectivity between the amygdala and the CA3, and increased connectivity between the prefrontal cortex and the CA1 were observed in the TLE rats compared to control rats. Moreover, FA values in the amygdala, the hippocampus and the entorhinal cortex, as well as the amygdala-CA3 and the prefrontal-CA1 connectivity correlated with the memory performance. Based on our results, both the microstructure and functional connections were impaired in memory-related brain regions of LIP-TLE rats. Furthermore, the abnormal changes in the microstructure and functional connectivity were related to behavioral deficits in object and location memory.

17.
Free Radic Biol Med ; 2019 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-31770582

RESUMO

Corticosteroid insensitivity is a feature of airway inflammation in chronic obstructive pulmonary disease (COPD). Erythromycin exhibits anti-inflammatory activity in COPD, but the concrete mechanism is still unclear. This study aimed to investigate the effects of erythromycin on corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) and U937 cells (a human monocytic cell line). PBMCs were collected from non-smokers, healthy smoker volunteers, and COPD subjects. U937 cells were incubated with or without erythromycin and stimulated with TNF-α in the presence or absence of cigarette smoke extract (CSE). The dexamethasone (Dex) concentration required to achieve 50% inhibition of TNF-α-induced interleukin (IL)-8 production was determined and the mitogen-activated protein kinase (MAPK)/Activator protein-1 (AP-1) pathway was also evaluated. Erythromycin improved corticosteroid sensitivity in PBMCs obtained from COPD patients and CSE-treated U937 cells. This improvement in corticosteroid sensitivity was associated with reduced c-Jun expression, which resulted from the inhibition of P38 Mitogen-activated protein kinase (P38MAPK), extracellular signal-regulated protein kinase (ERK)1/2, and c-Jun N-terminal kinase (JNK) phosphorylation. Erythromycin had no effects on the phosphorylated and total protein expression levels of P38MAPK and ERK; however, it induced inhibition of the phosphorylated and total protein expression levels of JNK. This study provides evidence that erythromycin restores corticosteroid sensitivity in PBMCs and U937 cells. JNK inhibition by erythromycin restores corticosteroid sensitivity via the inhibition of c-Jun expression. Thus, JNK/c-Jun is a potential novel therapeutic target for COPD.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31771125

RESUMO

An understanding of the enrichment mechanisms of cadmium (Cd) and arsenic (As) in the process of rock weathering and soil formation is essential to develop agriculture according to local conditions. However, the enrichments of soil Cd and As under natural background conditions in karst areas are still uncertain. The enrichment factor, geo-accumulation index, redundancy analysis, and other methods were used to analyze the enrichment degree and the influencing factors of Cd and As on 5 rock-soil profiles and 15 topsoil samples, which were collected from a karst forest area in Libo County, Guizhou Province. The results showed that the enrichment process was divided into three stages. In the first stage, Cd and As were enriched in carbonate rocks, and their mean concentrations were 1.65 and 3.9 times those of the corresponding abundance of the crust. In the second stage, the enrichment of the parent rock into the soil, the enrichment factors of Cd and As in the parent material horizon relative to the bedrock horizon were 9.2 and 2.82, respectively. The third stage refers to the enrichments of Cd and As in the topsoil, where Cd enrichment was more obvious than that of As. Soil organic matter (SOM) and phosphorus (P) are important factors that influenced the enrichments of Cd and As in the topsoil. The functional groups of SOM were complexed with Cd and As; P easily formed precipitates with Cd, and the tree litter was fed back to the topsoil, which may be the reason for the surface enrichment of Cd and As. This study will help the scientific community understand the enrichment mechanisms of soil Cd and As in karst areas.

19.
Genome Med ; 11(1): 73, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31771646

RESUMO

BACKGROUND: Acute myeloid leukemia (AML), caused by the abnormal proliferation of immature myeloid cells in the blood or bone marrow, is one of the most common hematologic malignancies. Currently, the interactions between malignant myeloid cells and the immune microenvironment, especially T cells and B cells, remain poorly characterized. METHODS: In this study, we systematically analyzed the T cell receptor and B cell receptor (TCR and BCR) repertoires from the RNA-seq data of 145 pediatric and 151 adult AML samples as well as 73 non-tumor peripheral blood samples. RESULTS: We inferred over 225,000 complementarity-determining region 3 (CDR3) sequences in TCR α, ß, γ, and δ chains and 1,210,000 CDR3 sequences in B cell immunoglobulin (Ig) heavy and light chains. We found higher clonal expansion of both T cells and B cells in the AML microenvironment and observed many differences between pediatric and adult AML. Most notably, adult AML samples have significantly higher level of B cell activation and more secondary Ig class switch events than pediatric AML or non-tumor samples. Furthermore, adult AML with highly expanded IgA2 B cells, which might represent an immunosuppressive microenvironment, are associated with regulatory T cells and worse overall survival. CONCLUSIONS: Our comprehensive characterization of the AML immune receptor repertoires improved our understanding of T cell and B cell immunity in AML, which may provide insights into immunotherapies in hematological malignancies.

20.
Eur J Clin Nutr ; 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31776452

RESUMO

BACKGROUND: A significant shift toward high folate concentrations has been taking place following the mandatory folate fortification. Yet the relationship between folate and health outcomes beyond neural tube defects remains understudied. We longitudinally examined relationships between serum folate and risk of cardiovascular death. METHODS: We analyzed data of 3116 adults aged ≥19 who participated in the Third National Health and Nutrition Examination Survey, 1991-1994 and were diagnosed with hypertension. Vital status was followed through December 31, 2010. Cox regression was used to estimate hazard ratios (HRs) of cardiovascular deaths for individuals with serum folate in the first quartile and fourth quartile compared with the patients with interquartile folate. RESULTS: After 33627 person years (p*ys) of follow-up, 1298 deaths were recorded with 638 cardiovascular disease (CVD) deaths (109 strokes and 529 heart diseases). A U-shaped association appeared after multivariable adjustment for heart disease, acute myocardial infarction, and overall CVD deaths. The mortality rate for heart disease in patients with low, moderate, and high folate were 12.18/1000 p*ys, 14.12/1000 p*ys, and 23.80/1000 p*ys, respectively, and the corresponding adjusted HRs were 1.79 (95% confidence interval, CI = 1.63-1.98), 1.00 (reference), and 1.31 (1.17-1.46). The HRs of acute myocardial infarction were 2.28 (1.80-2.88), 1.00 (reference), and 1.77 (1.42-2.20) for hypertensive patients with serum folate in low quartile, interquartile, and high quartile, respectively. CONCLUSIONS: Among hypertensive adults, both low and high folate were associated with an elevated risk of dying from cardiovascular diseases compared with adults with moderate serum folate concentration.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA