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1.
BMC Genomics ; 21(1): 39, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931709

RESUMO

BACKGROUND: Hypoxia mediated pulmonary hypertension (HPH) is a lethal disease and lacks effective therapy. CircRNAs play significant roles in physiological process. Recently, circRNAs are found to be m6A-modified. The abundance of circRNAs was influenced by m6A. Furthermore, the significance of m6A circRNAs has not been elucidated in HPH yet. Here we aim to investigate the transcriptome-wide map of m6A circRNAs in HPH. RESULTS: Differentially expressed m6A abundance was detected in lungs of HPH rats. M6A abundance in circRNAs was significantly reduced in hypoxia in vitro. M6A circRNAs were mainly from protein-coding genes spanned single exons in control and HPH groups. Moreover, m6A influenced the circRNA-miRNA-mRNA co-expression network in hypoxia. M6A circXpo6 and m6A circTmtc3 were firstly identified to be downregulated in HPH. CONCLUSION: Our study firstly identified the transcriptome-wide map of m6A circRNAs in HPH. M6A can influence circRNA-miRNA-mRNA network. Furthermore, we firstly identified two HPH-associated m6A circRNAs: circXpo6 and circTmtc3. However, the clinical significance of m6A circRNAs for HPH should be further validated.

2.
J Clin Lab Anal ; : e23134, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31981468

RESUMO

BACKGROUND: Recently, the rs5370 single nucleotide polymorphisms (SNPs) of Endothelin-1 (EDN1) showed association with the susceptibility of childhood primary nephrotic syndrome (CPNS). This study aims to investigate potential relationships between other EDN1 SNPs and CPNS. METHODS: Seven SNPs (rs5370, rs10478723, rs1476046, rs1800541, rs2070698, rs2071942, and rs9296344) of the EDN1 gene were genotyped in 579 CPNS patients and 586 age-matched healthy children. Then, we analyzed potential associations of the six SNPs with susceptibility of CPNS by using rs5370 as a conditional variant in a logistic regression model. SNP-SNP interaction analysis was performed to investigate the joint effects of the seven SNPs in the pathogenesis of CPNS. RESULTS: Independent with rs5370, only rs9296344 significantly associated (T vs C, odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.57-0.88, P = .001) with the susceptibility of CPNS. Meanwhile, no joint effect among the analyzed seven SNPs was discovered in this study. CONCLUSIONS: This study discovered that C allele of rs9296344 on EDN1 is a novel independent risk factor for CPNS.

3.
ACS Appl Mater Interfaces ; 12(3): 4135-4142, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31880903

RESUMO

A combinational effect of nanostructured crystallites and π-bonded interfaces is much attractive in solving the conflict between strength/hardness and toughness to design extrinsically superhard materials with enhanced fracture toughness and/or other properties such as tunable electronic properties. In the present work, taking the experimentally observed π-bonded interfaces in nanostructured diamond as the prototype, we theoretically investigated their stabilities, electronic structures, and mechanical strengths with special consideration of the size effect of nanocrystallites or nanolayers. It is unprecedentedly found that the π-bonded interfaces exhibit tunable electronic semiconducting properties, superior fracture toughness, and anomalously large creep-like plasticity at the cost of minor losses in strength/hardness; such unique combination is uncovered to be attributed to the ductile bridging effect of the sp2 bonds across the π-bonded interface that dominates the localized plastic flow channel. As the length scale of nanocrystallites/nanolayers is lower than a critical value, however, the first failure occurring inside nanocrystallites/nanolayers features softening and embrittling. These findings not only provide a novel insight into the unique strengthening and toughening origin observed in ultrahard nanostructured diamonds consisting of nanotwins, nanocomposites, and nanocrystallites but also highlight a unique pathway by combining the nanostructured crystallites and the strongly bonded interface to design the novel superhard materials with superior toughness.

4.
Medicine (Baltimore) ; 98(51): e18386, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31861001

RESUMO

RATIONALE: Pulmonary embolisms (PEs) are caused by emboli, which mostly originate from deep venous thrombi that travel to and suddenly block the pulmonary arteries. The emboli are usually thrombi, and right atrial myxoma emboli are rare. PATIENT CONCERNS: A 55-year-old man presented with shortness of breath and syncope. We proceeded with computed tomography pulmonary angiography (CTPA) and transthoracic echocardiogram (TTE), the results of which suggested that the diagnosis was a right atrial mass. DIAGNOSIS: A definitive diagnosis compatible with a right atrial myxoma (RAM) with tumoral pulmonary emboli after surgical excision was made. INTERVENTION: Right atrial and pulmonary artery embolectomy. OUTCOMES: The patient followed an uneventful course during the 6 years of follow-up after surgery. According to a review of the literature, RAMs are often not diagnosed in a timely manner or even go completely undiagnosed. TTE, transesophageal echocardiography (TEE), CT, magnetic resonance imaging (MRI), and positron emission tomography/computed tomography may be helpful in the preoperative diagnosis. Surgical removal of the masses from the atrium and pulmonary arteries was relatively uneventful. LESSONS: RAMs should be considered unlikely reasons for fatal pulmonary embolisms.


Assuntos
Átrios do Coração/diagnóstico por imagem , Neoplasias Cardíacas/diagnóstico por imagem , Mixoma/diagnóstico por imagem , Embolia Pulmonar/etiologia , Angiografia por Tomografia Computadorizada , Ecocardiografia , Átrios do Coração/cirurgia , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Mixoma/patologia , Mixoma/cirurgia , Embolia Pulmonar/cirurgia
5.
Chem Rev ; 119(23): 11980-12031, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710485

RESUMO

In the past decade, two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides (MXenes) have attracted attention and interest from the scientific community due to their superior mechanical strength and flexibility, physical/chemical properties, and multiple exciting functionalities. Among these materials, the ingenious and effective combination of the mechanical and functional properties of MXenes provides a promising opportunity for designing flexible and wearable devices. This review summarizes the recent research progress in the structural stabilities, mechanical strength and deformation mechanism, strain-tunable energy storages, and catalytic and thermoelectric properties along with certain strain modifications and strain-controllable electronic/topological properties of MXenes from a combined theoretical and experimental perspective and illustrates their electronic origins. Taking the design principles as a focus, the theoretical predictions provide guidance, while the experimental work gives a thorough validation, thus setting the foundation for the current scientific achievements, challenges, and prospects in the field of MXenes.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31635386

RESUMO

To remove high concentrations of ammonium from groundwater, pure oxygen and compressed air were fed into a chemical catalytic filter and the ammonium removal efficiency was investigated. The experimental results showed that the oxygen content is the critical limiting factor for ammonium removal. Aeration with 40 mL/min pure oxygen or 100 mL/min compressed air from the bottom of the filter supplied adequate oxygen and approximately 4.2 mg/L of ammonium was removed in this process. Moreover, when the aeration device was moved to 1/3 of the height of the filter bed, the required flow rates of pure oxygen and compressed air decreased further and the turbidity removal was improved. Pouring ozone gas into the filter system, which can inactivate bacteria effectively, can also obtain the remarkable ammonium removal, indicating that ammonium removal was mainly due to the chemical catalytic oxidation in this process rather than the biodegradation. This study provides a novel method for removing high concentrations of ammonium from groundwater.

7.
Phys Chem Chem Phys ; 21(40): 22629-22638, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31591617

RESUMO

Solid solution strengthening has been widely used in designing various high-performance biocompatible Mg-based alloys, but its transferability to other biocompatible metals such as Zn-based alloys is questionable or nearly absent. In the present study, an ab initio informed Peierls-Nabarro model and Leyson et al.'s strengthening model are used for a systematic investigation on solute strengthening in Zn-based alloys, which is compared with the widely studied Mg-based alloys. Although an inverse relationship was revealed between volume misfit εb and chemical misfit εSFE for both Zn-based and Mg-based alloys, most solutes would however result in positive εb and negative εSFE for Zn-based alloys, differing from Mg-based alloys. With εb and εSFE as two key descriptors, a generalized scaling diagram is finally drawn for a fast evaluation of solid solution strengthening in Zn-based alloys, indicating that the alkaline-earth and rare earth elements are better strengtheners for Zn-based alloys, which provides a general rule in designing novel biocompatible materials.

8.
Int J Biol Macromol ; 141: 60-67, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31446108

RESUMO

In this article, novel epoxy resin-based hierarchical porous polymers (HPSs) have been prepared through a non-sol-gel and template-free approach using crystalline trimethylolpropane (TMP) as porogen. The polymers exhibit dimensional stability and possess 3-dimentional interconnected multi-scale pores. In range of 50 µm~10 nm are ultra-macro-pore in between skeleton, macro-pore on skeleton and meso-pore in network, respectively. The porosity and specific surface area can be adjusted in range of 91.2-82.5% and 225-156 m2/g, respectively. Using three kinds of hierarchical porous polymers as supports phospholipase D (PLD) was effectively immobilized through physical adsorption. Owing to high porosity of the support and improvement of mass transfer the loading amount of PLD reached as high as 223 mg/gsupport and the corresponding specific activity achieved up to 3.75 × 103 U/gsupport. Under optimized conditions and the phosphatidylserine (PS) yield reached 95.5% within 40 min at 45 °C. The immobilized PLD exhibited not only better storage stability and but also resistance to pH and thermal inactivation than free PLD. It was found that 73.5% of PS yield retained after 12 cycling reuses.

9.
Phys Chem Chem Phys ; 21(29): 16095-16107, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31290502

RESUMO

Much effort was devoted towards the rational design of ultrastrong transition metal borides (TMBs) with remarkable mechanical properties and excellent stabilities, owing to promising applications in machining, drilling tools and protective coatings for the aerospace industry. Although an enormous number of investigations have been performed on these TMBs under normal conditions, studies on the stability and mechanical strength in harsh high-pressure environments, which are critical for safe service behavior and a realistic understanding of stabilities and strengthening mechanisms, are yet nearly absent. In this work, taking 5d TMB2 (TM = Hf, Ta, W, Re, Os, Ir and Pt) as an illustration, we performed comprehensive high-throughput first-principles screening for thermodynamically stable and metastable structures under various pressures. Four experimentally observed structures are found to be thermodynamically feasible for most 5d TMB2 (TM = Hf, Ta, W, Re, Os and Ir) at 0 and 100 GPa. By exploiting orbital-decomposed electronic structures, we reveal that the pressure-induced stabilization and phase transitions of 5d TMB2 can be rationalized by the splitting of bonding and antibonding states around the Fermi level. Further investigations on the pressure-induced strengthening indicate that 5d TMB2 in the hP6[194] structure exhibit a profound strengthening effect under high pressure, which can be rationalized by the proposed strengthening factor η, but η fails in the oP6[59] structure due to the changed instability modes at different pressures. These findings suggest the necessity to explore the plasticity parameters for a realistic understanding of pressure-induced strengthening in TMBs, providing a strong argument for rules based on bond parameters at equilibrium in designing strong solids.

10.
Environ Sci Technol ; 53(15): 8757-8766, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31241323

RESUMO

Heterogeneous oxidation of SO2 is one of the promising mechanisms to account for high loading of sulfate during severe haze periods in China. Our earlier work reported on the SO2 oxidation by OH and NO2 produced during 250 nm nitrate photolysis (Environ. Sci. Technol. Lett. 2019, 6, 86-91). Here, we extend that work to examine sulfate production during nitrate photolysis at 300 nm irradiation, which can additionally generate NO2- or HNO2, N(III). Flow cell/in situ Raman experiments showed that the reactive uptake coefficient of SO2, γSO2, can be expressed as γSO2 = 1.64 × pNO3-, where pNO3- is the nitrate photolysis rate in the range of (1.0-8.0) × 10-5 M s-1. Our kinetic model with the pNO3- predicts that N(III) is the main contributor to the SO2 oxidation, followed by NO2 contribution. Furthermore, the addition of OH scavengers (e.g., glyoxal or oxalic acid) does not suppress the sulfate production because of the reduced N(III)-consuming reactions and the high particle pH sustained by their presence. Our calculations illustrate that under characteristic haze conditions, the nitrate photolysis mechanism can produce sulfate at ∼1 µg m-3 h-1 at pH 4-6 and pNO3- = 10-5 M s-1. The present study highlights the importance of in-particle nitrate photolysis in heterogeneous oxidation of SO2 by reactive nitrogen (NO2-/HNO2 and NO2) under atmospherically relevant actinic irradiation. However, the nitrate photolysis rate constant needs to be better constrained for ambient aerosols.


Assuntos
Sulfatos , China , Umidade , Concentração de Íons de Hidrogênio , Fotólise
12.
Cancer Manag Res ; 11: 2363-2369, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30962723

RESUMO

Objective: Heavy ions have contributed to tumor site-specific radiotherapy and are a major health risk for astronauts. The purpose of this study was to investigate the changes in gene expression in peripheral lymphocytes of cancer patients and astronauts exposed to 12C ions, and identify suitable molecular biomarkers for health monitoring. We also aimed to observe the effects of treatment and the level of damage, by comparing the transcriptional profiles of human lymphocyte cell lines exposed to 12C ion beams at doses of 0-2.0 Gy. Materials and methods: A human lymphocyte cell line was irradiated with 12C ion beams at 0, 0.1, 0.5, and 2.0 Gy and transcriptional profiles were evaluated using the Agilent human gene expression microarray at 24 hours after irradiation. Differentially expressed genes were identified using a fold change of ≥2.0. Representative genes were further validated by RT-PCR. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to determine the roles of differentially expressed mRNAs. Results: Based on the microarray assays, 1,113 genes were upregulated and 853 genes were downregulated in human lymphocyte cells irradiated with 0.1 Gy 12C ion beams compared with the control group, 1,095 genes were upregulated and 1,220 genes were downregulated in cells irradiated with 0.5 Gy 12C ion beams, and 1,055 genes were upregulated and 1,356 genes were downregulated in cells irradiated with 2.0 Gy. A total of 504 genes were differentially expressed in all irradiated groups, of which 88 genes were upregulated and 416 genes downregulated. Most of these altered genes were related to the cell cycle, apoptosis, signal transduction, DNA transcription, repair, and replication. The expression differences were further confirmed by RT-PCR for a subset of differentially expressed genes. Conclusion: Differentially expressed genes between treatment and control groups at 24 hours post-irradiation increased as the radiation dose increased; upregulated genes gradually decreased and downregulated genes increased. Our data indicated that 12C ion beams could repress a number of genes in a dose-dependent manner, which might lead to the failure of multiple cellular biological functions.

13.
Prostate ; 79(7): 709-719, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30825345

RESUMO

OBJECTIVES: The predictive value of the histological parameters and molecular markers for neoadjuvant hormonal therapy (NHT) in prostate cancer (PCa) has not been well established. The aim of this study is to determine pathological variables that can predict differences in response to NHT in PCa. METHODS: A total of 85 locally high risk PCa patients with matched preoperative needle biopsies and radical prostatectomy (RP) specimens were included. All patients were treated with NHT for at least 3 months. We quantified the response to NHT using a new proposed pathological grading system. The system classified tumors into five groups (grades 0-4) according to the severity of histological response. We then categorized the PCa patients into drug-sensitive (DS) group (Grades 2-4) and drug-resistant (DR) group (Grades 0-1). Two pathologists assessed each pretreated tumors for presence or absence of nine morphological features. The expression of androgen receptor (AR), ERG, and PTEN were evaluated by immunohistochemistry (IHC) as well. Statistical analysis was performed to identify significant associations between differentially histological response to NHT and morphological features as well as molecular aberrations. We evaluated different prediction models using receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) analysis. RESULTS: 73% (n = 62/85) of tumors in our cohort belonged to DS group, whereas 27% (n = 23/85) of tumors were DR. Univariate logistic analysis suggested four pathological variables, cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies were significantly associated with DR effect, all with P-value < 0.05. Multivariate logistic regression analysis revealed that the three parameters as significant predictive factors for predicting DR effect. These were macronucleoli (RR = 4.008, P = 0.002), ductal adenocarcinoma differentiation (RR = 11.659, P = 0.009) and PTEN loss expression (RR = 7.275, P = 0.015). The AUC of three integrated indicators model was 0.781. CONCLUSIONS: Our study suggested that the presence of tumor cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies are of value in predicting tumor response to NHT regimen. Multivariate logistic regression analysis revealed the performance of combined pathological indicators in predicting DR response was better than that of model based on individual factor alone.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Hormonais/administração & dosagem , Terapia Neoadjuvante/métodos , Neoplasias da Próstata/tratamento farmacológico , Adenocarcinoma/classificação , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Antagonistas de Androgênios , Biópsia por Agulha , Resistencia a Medicamentos Antineoplásicos/fisiologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase/biossíntese , Valor Preditivo dos Testes , Prognóstico , Prostatectomia , Neoplasias da Próstata/classificação , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/biossíntese , Regulador Transcricional ERG/biossíntese
15.
Thromb Res ; 176: 85-94, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30784777

RESUMO

INTRODUCTION: Acute pulmonary embolism (APE) is a cardiovascular disease with high morbidity and mortality. Although the anatomical obstruction of the pulmonary vascular bed initiates APE, recent studies have suggested that vasoconstrictors in the renin-angiotensin system (RAS) play a role in the severity of APE. MATERIALS AND METHODS: We performed a 5-year retrospective clinical study to analyze the key RAS components in APE patients, including angiotensin converting enzyme (ACE), ACE2, angiotensin II (Ang II) and angiotensin 1-7(Ang(1-7)). The role of RhoA-Rho associated kinase (ROCK) signaling in regulating RAS vasoconstrictors was detected in rat pulmonary artery endothelial cells and in an APE rat model. RESULTS: In clinical study, we found that the levels of RAS vasoconstrictors were correlated with the clinical classification of APE patients, ACE and Ang II were unregulated, whereas ACE2 and Ang(1-7) were downregulated in the high-risk group compared to the healthy volunteers. In animal study, we found that activated RhoA-ROCK signaling was responsible for the imbalance in RAS vasoconstrictors both in vitro and in vivo, and further evidence indicated that ROCK inhibitors (Y27632 or HA1077) and an ACE2 activator (Resorcinol naphthalein) restored the dysregulated RAS vasoconstrictors significantly and had a protective role in an APE rat model. CONCLUSIONS: Our study revealed that RhoA-ROCK signaling leads to RAS imbalance in APE patients, and ACE2 activation might be a novel therapeutic target in APE treatment.


Assuntos
Peptidil Dipeptidase A/metabolismo , Embolia Pulmonar/metabolismo , Transdução de Sinais , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Doença Aguda , Animais , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos Sprague-Dawley , Sistema Renina-Angiotensina
16.
Am J Physiol Lung Cell Mol Physiol ; 316(3): L547-L557, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30628484

RESUMO

Angiotensin-converting enzyme 2 (ACE2) protects against hypoxic pulmonary hypertension (HPH) by inhibiting the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). Under hypoxia, the hypoxia-inducible factor 1α (HIF-1α) inhibits ACE2 indirectly; however, the underlying mechanism is unclear. In the present study, we found that exposure to chronic hypoxia stimulated microRNA (miRNA) let-7b expression in rat lung via a HIF-1α-dependent pathway. Let-7b downregulated ACE2 expression by directly targeting the coding sequence of ACE2. Our in vitro and in vivo results revealed that let-7b contributed to the pathogenesis of HPH by inducing PASMCs proliferation and migration. Let-7b knockout mitigated right ventricle hypertrophy and pulmonary vessel remodeling in HPH by restoring ACE2 expression. Overall, we demonstrated that HIF-1α inhibited ACE2 expression via the HIF-1α-let-7b-ACE2 axis, which contributed to the pathogenesis of HPH by stimulating PASMCs proliferation and migration. Since let-7b knockout alleviated the development of HPH, let-7b may serve as a potential clinical target for the treatment of HPH.


Assuntos
Hipertensão Pulmonar/genética , MicroRNAs/genética , Peptidil Dipeptidase A/genética , Remodelação Vascular/genética , Animais , Proliferação de Células/fisiologia , Técnicas de Inativação de Genes , Hipertensão Pulmonar/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , Pulmão/metabolismo , Masculino , Miócitos de Músculo Liso/metabolismo , Artéria Pulmonar/patologia , Ratos Sprague-Dawley , Remodelação Vascular/fisiologia
17.
J Clin Lab Anal ; 33(1): e22623, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30006974

RESUMO

BACKGROUND: The association between gene polymorphisms and the risk of primary nephrotic syndrome (PNS) is uncovering recently. This study aims to investigate the relationship between single nucleotide polymorphisms (SNPs) on HLA-DQA1 gene and the risk of PNS. METHODS: In this study, we genotyped eight single nucleotide polymorphisms (SNPs) in the HLA-DQA1 gene in 501 PNS patients and 532 healthy people in Chinese population. Then we analyzed associations of these SNPs with the clinical features in primary nephrotic syndrome of children in Chinese population. RESULTS: Significant associations with PNS were found on missense SNP rs1129740 (GG vs AA, odds ratio (OR) = 1.987, 95% confidence interval (CI) = 1.468-2.652, P = 0.00177049) and rs1047992 (AA vs GG, OR = 1.857, 95% CI = 1.325-2.391, P = 1.1073E-10) of the HLA-DQA1 gene. CONCLUSIONS: This work suggests SNPs of HLA-DQA1 are risk factors for PNS in Chinese population, which implies roles of immune response in the pathogenesis of PNS.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Predisposição Genética para Doença , Cadeias alfa de HLA-DQ/genética , Síndrome Nefrótica , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Humanos , Lactente , Desequilíbrio de Ligação , Masculino , Síndrome Nefrótica/epidemiologia , Síndrome Nefrótica/genética
18.
J Environ Sci (China) ; 77: 346-353, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30573099

RESUMO

Manganese and ammonium pollution in surface water sources has become a serious issue. In this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simultaneous removal of ammonium and manganese from surface water using a manganese co-oxide filter film (MeOx). The results showed that the manganese removal efficiency of MeOx in the absence of ammonium was high and stable, and the removal efficiency could reach 70% even at 5.5 °C. When the influent ammonium concentration was lower than 0.7 mg/L, ammonium and manganese could be removed simultaneously. However, at an ammonium concentration of 1.5 mg/L, the manganese removal efficiency of the filter gradually decreased with time (from 96% to 46.20%). Nevertheless, there was no impact of manganese on ammonium removal. The mechanism by which ammonium negatively affected manganese removal was investigated, demonstrating that ammonium affected manganese removal mainly through two possible mechanisms. On one hand, the decreased pH caused by ammonium oxidation was unfavorable for the oxidation of manganese by MeOx; on the other hand, the presence of ammonium slowed the growth of new MeOx and retarded the increase in the specific surface area of the MeOx-coated sand, and induced changes in the morphology and crystal structure of MeOx. Consequently, the manganese removal efficiency of the filter decreased when ammonium was present in the inlet water.


Assuntos
Compostos de Amônio/química , Compostos de Amônio/isolamento & purificação , Compostos de Manganês/química , Manganês/química , Manganês/isolamento & purificação , Óxidos/química , Purificação da Água/métodos , Água/química , Filtração , Oxirredução , Fatores de Tempo , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
19.
Respir Res ; 19(1): 254, 2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30547791

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is related to inflammation, and the lncRNA H19 is associated with inflammation. However, whether PDGF-BB-H19-let-7b-AT1R axis contributes to the pathogenesis of PAH has not been thoroughly elucidated to date. This study investigated the role of H19 in PAH and its related mechanism. METHODS: In the present study, SD rats, C57/BL6 mice and H19-/- mice were injected with monocrotaline (MCT) to establish a PAH model. H19 was detected in the cytokine-stimulated pulmonary arterial smooth muscle cells (PASMCs), serum and lungs of rats/mice. H19 overexpression and knockdown experiments were also conducted. A dual luciferase reporter assay was used to explore whether let-7b is a sponge miRNA of H19, and AT1R is a novel target of let-7b. A CCK-8 assay and flow cytometry were used to analyse cell proliferation. RESULTS: The results showed that H19 was highly expressed in the serum and lungs of MCT-induced rats/mice, and H19 was upregulated by PDGF-BB in vitro. H19 upregulated AT1R expression via sponging miRNA let-7b following PDGF-BB stimulation. AT1R is a novel target of let-7b. Moreover, the overexpression of H19 and AT1R could facilitate PASMCs proliferation in vitro. H19 knockout protected mice from pulmonary artery remodeling and PAH following MCT treatment. CONCLUSION: Our study showed that H19 is highly expressed in MCT-induced rodent lungs and upregulated by PDGF-BB. The H19-let-7b-AT1R axis contributed to the pathogenesis of PAH by stimulating PASMCs proliferation. The H19 knockout had a protective role in the development of PAH. H19 may be a potential tar-get for the treatment of PAH.


Assuntos
Hipertensão Pulmonar/metabolismo , MicroRNAs/biossíntese , Monocrotalina/toxicidade , Miócitos de Músculo Liso/metabolismo , RNA Longo não Codificante/biossíntese , Receptores de Angiotensina/biossíntese , Indutores da Angiogênese/farmacologia , Animais , Becaplermina/farmacologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Hipertensão Pulmonar/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos de Músculo Liso/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , RNA Longo não Codificante/agonistas , Ratos , Ratos Sprague-Dawley
20.
Phys Chem Chem Phys ; 20(47): 29684-29692, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30475359

RESUMO

Two-dimensional (2D) transition metal carbides (MXenes) exhibit excellent thermodynamic stability and remarkable mechanical strength and flexibility, as well as rich functionality, which attract considerable interest due to their potential application for high-performance flexible and stretchable devices. However, premature phonon instability of some non-hybrid MXenes was recently found to intrinsically limit their strength and flexibility, evoking passionate curiosity in pursuing an effective solution for more impressive mechanical properties. In this work, on the basis of an alloying strengthening mechanism, a combinational strategy is proposed to build ordered hybrid M2''M'C2O2 (M'' = Mo, W; M' = Ti, Zr, Hf) with remarkable dynamic stability and superior mechanical properties by hindering the premature phonon instability originating from the outer transition metals. By means of comprehensive screening, symmetrical-Mo2TiC2O2 is interestingly found to possess excellent stability at equilibrium and outstanding tolerance to phonon instability during straining compared to its Ti counterpart, being attributed to the character of the robust Mo-dz2 and O-pz hybridization. Although similar optical phonon soft modes appear in Ti3C2O2 and Mo2TiC2O2 under multiple loadings, the latter is much stiffer during straining. An in-depth analysis of deformed electronic structures reveals that a strain-induced increasing density of states in the vicinity of the Fermi level mainly composed of Mo-dz2 states facilitates the fatal phonon softening in Mo2TiC2O2 under biaxial tension, while differing from the mechanical instability in Ti3C2O2 triggered by a Peierls transition. Our findings provide a novel stabilization and strengthening strategy for 2D materials, and pave a new way for searching for 2D material candidates in designing flexible devices.

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