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1.
Artigo em Inglês | MEDLINE | ID: mdl-34797636

RESUMO

Interlayer charge transfer (CT) between PtSe2 and WS2 is studied experimentally. Layer-selective pump-probe and photoluminescence quenching measurements reveal ultrafast interlayer CT in the heterostructure formed by bilayer PtSe2 and monolayer WS2, confirming its type-II band alignment. The CT facilitates the formation of the interlayer excitons with a lifetime of several hundred ps to 1 ns, a diffusion coefficient of 0.9 cm2 s-1, and a diffusion length reaching 200 nm. These results demonstrate the integration of PtSe2 with other materials in van der Waals heterostructures with novel charge-transfer properties and help develop fundamental understanding on the performance of various optoelectronic devices based on heterostructures involving PtSe2.

2.
J Hazard Mater ; 424(Pt C): 127584, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34736214

RESUMO

In this work, the mechanism of Pb(II)-mediated precipitation transformation to improve the removal of Cr(VI)-oxyanion on biogenic hydroxyapatite (BHAp) were investigated. The Pb(II)-preloading formed pyromorphite [Pb5(PO4)3Cl] precipitate on the BHAp surface (Pb@BHAp), thus causing an increase of 2.2 times in the uptake of Cr(VI) by Pb@BHAp at pH of 2.4. It was primarily due to the dissolution of Pb5(PO4)3Cl accompanied with the release of Pb(II), resulting in the rapid formation of crocoite (PbCrO4). Although the Ksp of Pb5(PO4)3Cl was approximately 23 orders of magnitude lower than that of PbCrO4, Pb(II)-mediated precipitation transformation could still occur. XRD and SEM-EDX analyses demonstrated that the process was a time-dependent that included rapid crystal precipitation in the initial 10 min and subsequent precipitate accumulation for several hours. The Pb(II) released from the dissolution of Pb5(PO4)3Cl was immediately immobilized by Cr(VI); therefore, it did not cause any retention risk of Pb(II) in the solution. Furthermore, a small quantity of Cr(VI) could be reduced to Cr(III) by BHAp, and Cr(III) could enter into the BHAp lattice for the exchange of Ca(II). This study provides a new insight into the resource utilization of Pb-bearing BHAp and a potential method for the successive removal of Pb(II) and Cr(VI).

3.
Nano Lett ; 21(19): 8035-8042, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34605657

RESUMO

The van der Waals (vdW) heterostructures have rich functions and intriguing physical properties, which has attracted wide attention. Effective control of excitons in vdW heterostructures is still urgent for fundamental research and realistic applications. Here, we successfully achieved quantitative tuning of the intralayer exciton of monolayers and observed the transition from intralayer excitons to interlayer excitons in WS2/MoSe2 heterostructures, via hydrostatic pressure. The energy of interlayer excitons is in a "locked" or "superstable" state, which is not sensitive to pressure. The first-principles calculation reveals the stronger interlayer interaction which leads to enhanced interlayer exciton behavior in WS2/MoSe2 heterostructures under external pressure and reveals the robust peak of interlayer excitons. This work provides an effective strategy to study the interlayer interaction in vdW heterostructures and reveals the enhanced interlayer excitons in WS2/MoSe2, which could be of great importance for the material and device design in various similar quantum systems.

4.
Dalton Trans ; 50(42): 14967-14977, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34622897

RESUMO

Luminescent metal-organic frameworks (LMOFs) as chemosensors, can sense various analytes, such as heavy metal ions, antibiotics, pesticides, and small biological molecules. Based on the fluorescence characteristics of LMOFs, a variety of logic gates have been developed. In this review, we mainly discuss some common logic systems based on LMOFs, and then summarize the strategies of constructing logic gates from two perspectives. One is based on superior characteristics of MOFs, which can be synthesized from Ln3+ based MOFs (Ln-MOFs) or form hybrids by encapsulating different materials, including metal ions, dyes, and quantum dots (QDs). The other is to control the presence of inputs by reactions between different reactants and then further control switches of logic gates. Additionally, the common sensing mechanisms of LMOFs in logic gates are discussed. In the end, we have envisioned MOFs that possess a promising future in logic computing areas.

5.
ERJ Open Res ; 7(3)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34350289

RESUMO

Hospitalised #AECOPD are characterised by multiple facets of aetiology. The clinical interpretation of the composite phenotypes of AECOPD and the robustness of the AECOPD phenotype need to be discussed further. https://bit.ly/3grzQEO.

6.
J Thorac Dis ; 13(7): 4322-4338, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34422359

RESUMO

Background: Despite substantial evidence on the contribution of the diversity of the gut microbiome to the pathogenesis of asthma and allergic diseases, little is known about their relationship with asthma severity and/or clinical phenotypes. We analyzed the difference in composition of the gut microbiome between subjects with asthma and healthy subjects and explored its role in the development of asthma. Methods: Fecal samples from 15 subjects with severe asthma (SA), 14 with non-severe asthma (NSA), and 15 healthy subjects were assessed by 16S ribosomal RNA gene sequencing methods to identify the gut bacterial composition. Results: Compared with those in the NSA group, patients in the SA group had a higher dose of inhaled corticosteroids, and there were more atopic subjects (60% vs. 35.7%, respectively). No significant differences were found at the phylum level either in operational taxonomic unit numbers or in diversity scores among the SA, NSA, and healthy groups. However, at the family level, the relative abundance of Acidaminococcaceae in the SA group was remarkedly lower than that in the group with healthy subjects (P<0.05). Furthermore, Veillonellaceae and Prevotellaceae were significantly more common in samples from the SA group than in those from the NSA group (P<0.05). In the SA group, positive correlations were observed between the relative abundance of Veillonellaceae and mid-expiratory flow 25% (MEF25%) predicted (r=0.538, P=0.047), as well as between the relative abundance of Acidaminococcaceae and body mass index (r=0642, P=0.010). Principal component analysis suggested that the relative abundances of Acidaminococcaceae and Prevotellaceae were associated with severe asthma. Moreover, we found that class Betaproteobacteria, order Burkholderiales, and family Alcaligenaceae were significantly different among the groups defined by serum immunoglobulin E (IgE) levels. Conclusions: Our findings suggest that altered gut microbiome compositions are involved in the severity of asthma and that there are specific bacteria related to different asthma phenotypes in terms of serum IgE levels.

7.
Asthma Res Pract ; 7(1): 10, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34289896

RESUMO

BACKGROUND: Severe asthma is difficult to control. Therapeutic patient education enables patients to better understand their disease and cope with treatment, but the effect of therapeutic patient education in severe uncontrolled asthma is unclear. We evaluated whether therapeutic patient education is effective in improving asthma control and decreasing the frequency of exacerbations in severe uncontrolled asthma. METHODS: This was a prospective, observational, and self-controlled study that enrolled 40 subjects with severe uncontrolled asthma. Patients were seen at a clinic four times (on day 1 and after 3, 6, and 12 months). After baseline data collection, the subjects completed a therapeutic patient education program and were also followed-up via telephone after 1, 2, 4, 5, 7, 8, 9, 10, and 11 months to monitor asthma medication adherence and collect asthma-related information. RESULTS: Within the 1-year study period, a total of 23 exacerbations were recorded in 14 patients, seven of whom required emergency treatment and two of whom were hospitalized. Twelve months after the standardized therapeutic patient education program, pulmonary function and fractional exhaled nitric oxide levels improved significantly in all 40 patients. Moreover, the scores from three standardized asthma questionnaires and indices suggested improved quality of life in these patients with severe uncontrolled asthma. Serum levels of biomarkers reflecting asthma immune responses did not change between baseline and the 1-year follow-up time point. CONCLUSIONS: Therapeutic patient education is effective in improving asthma control and decreasing exacerbations in patients with severe uncontrolled asthma.

8.
Front Med (Lausanne) ; 8: 689568, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222293

RESUMO

Objective: Early identification of coronavirus disease 2019 (COVID-19) patients with worse outcomes may benefit clinical management of patients. We aimed to quantify pneumonia findings on CT at admission to predict progression to critical illness in COVID-19 patients. Methods: This retrospective study included laboratory-confirmed adult patients with COVID-19. All patients underwent a thin-section chest computed tomography (CT) scans showing evidence of pneumonia. CT images with severe moving artifacts were excluded from analysis. Patients' clinical and laboratory data were collected from medical records. Three quantitative CT features of pneumonia lesions were automatically calculated using a care.ai Intelligent Multi-disciplinary Imaging Diagnosis Platform Intelligent Evaluation System of Chest CT for COVID-19, denoting the percentage of pneumonia volume (PPV), ground-glass opacity volume (PGV), and consolidation volume (PCV). According to Chinese COVID-19 guidelines (trial version 7), patients were divided into noncritical and critical groups. Critical illness was defined as a composite of admission to the intensive care unit, respiratory failure requiring mechanical ventilation, shock, or death. The performance of PPV, PGV, and PCV in discrimination of critical illness was assessed. The correlations between PPV and laboratory variables were assessed by Pearson correlation analysis. Results: A total of 140 patients were included, with mean age of 58.6 years, and 85 (60.7%) were male. Thirty-two (22.9%) patients were critical. Using a cutoff value of 22.6%, the PPV had the highest performance in predicting critical illness, with an area under the curve of 0.868, sensitivity of 81.3%, and specificity of 80.6%. The PPV had moderately positive correlation with neutrophil (%) (r = 0.535, p < 0.001), erythrocyte sedimentation rate (r = 0.567, p < 0.001), d-Dimer (r = 0.444, p < 0.001), high-sensitivity C-reactive protein (r = 0.495, p < 0.001), aspartate aminotransferase (r = 0.410, p < 0.001), lactate dehydrogenase (r = 0.644, p < 0.001), and urea nitrogen (r = 0.439, p < 0.001), whereas the PPV had moderately negative correlation with lymphocyte (%) (r = -0.535, p < 0.001). Conclusions: Pneumonia volume quantified on initial CT can non-invasively predict the progression to critical illness in advance, which serve as a prognostic marker of COVID-19.

9.
ACS Appl Mater Interfaces ; 13(15): 18372-18379, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33830724

RESUMO

It is of great importance to develop useful methods to evaluate interfacial coupling strength noninvasively for exploring and optimizing heterointerface functionality. Recently, organic-inorganic van der Waals (vdW) heterostructures (HSs) composed of organic semiconductors and transition-metal dichalcogenides (TMD) have shown great potential for developing next-generation flexible optical, electrical, and optoelectrical devices. Since vdW coupling dominates the property of such a vdW HS, it is crucial to develop a method to evaluate its interfacial coupling strength noninvasively. In this work, by combining electrical force microscopy (EFM) and Raman and photoluminescence spectroscopic measurements, we were able to directly probe the coupling strength between monolayer MoSe2 and a copper phthalocyanine (CuPc) thin film. Especially, we also found a new Raman mode in HS due to the Davydov splitting of the CuPc thin film via strong interfacial coupling between the two materials. This new Raman mode was thus utilized as a probe to reveal the modulation of the coupling strength by changing post-treatment conditions. All of these results indicate that the method developed here is capable of evaluating the coupling strength of the MoSe2/CuPc HS effectively and innovatively, which aids in providing deep insights into such hybrid vdW HSs for future optical and optoelectrical applications.

10.
J Thorac Dis ; 13(2): 1215-1229, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33717594

RESUMO

Background: To develop machine learning classifiers at admission for predicting which patients with coronavirus disease 2019 (COVID-19) who will progress to critical illness. Methods: A total of 158 patients with laboratory-confirmed COVID-19 admitted to three designated hospitals between December 31, 2019 and March 31, 2020 were retrospectively collected. 27 clinical and laboratory variables of COVID-19 patients were collected from the medical records. A total of 201 quantitative CT features of COVID-19 pneumonia were extracted by using an artificial intelligence software. The critically ill cases were defined according to the COVID-19 guidelines. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to select the predictors of critical illness from clinical and radiological features, respectively. Accordingly, we developed clinical and radiological models using the following machine learning classifiers, including naive bayes (NB), linear regression (LR), random forest (RF), extreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), K-nearest neighbor (KNN), kernel support vector machine (k-SVM), and back propagation neural networks (BPNN). The combined model incorporating the selected clinical and radiological factors was also developed using the eight above-mentioned classifiers. The predictive efficiency of the models is validated using a 5-fold cross-validation method. The performance of the models was compared by the area under the receiver operating characteristic curve (AUC). Results: The mean age of all patients was 58.9±13.9 years and 89 (56.3%) were males. 35 (22.2%) patients deteriorated to critical illness. After LASSO analysis, four clinical features including lymphocyte percentage, lactic dehydrogenase, neutrophil count, and D-dimer and four quantitative CT features were selected. The XGBoost-based clinical model yielded the highest AUC of 0.960 [95% confidence interval (CI): 0.913-1.000)]. The XGBoost-based radiological model achieved an AUC of 0.890 (95% CI: 0.757-1.000). However, the predictive efficacy of XGBoost-based combined model was very close to that of the XGBoost-based clinical model, with an AUC of 0.955 (95% CI: 0.906-1.000). Conclusions: A XGBoost-based based clinical model on admission might be used as an effective tool to identify patients at high risk of critical illness.

11.
J Hydrol (Amst) ; 593: 125890, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33612857

RESUMO

Soil structure is an indicator of soil quality and its alterations following cropping system conversion or fertilization change evolve slowly. How such alterations vary with scale remains elusive. We investigated this based on the Rothamsted long-term wheat experiment (since 1843) in the UK. Triplicate cores 7 cm high and 10 cm in diameter were taken from plots that have been under different fertilizations or returned to natural woodland for more than one century for imaging using X-ray computed tomography with the voxel size being 40 µm. We then broke each core and sampled three aggregates from it to scan with the voxel size being 1.5 µm. For each core and aggregate sample, we calculated its pore size distribution, permeability and tortuosity. The results showed that the fertilization change >170 years ago reshaped the soil structure differently between the core scale and the aggregate scale. Macro-porosity of the pores (>40 µm) in the cores unfertilized or fertilized with inorganic fertilizers was low and the pores were poorly connected in the top 10 cm of soil, compared to those given farmyard manure or in the woodland. In all treatments, the pores in the core images were hydraulically anisotropic with their permeability in the horizontal direction being higher than that in the vertical direction, whereas the aggregates were comparatively isotropic. The fertilization affected image porosity and permeability at core scale more significantly than at aggregate scale, and the aggregates fertilized with farmyard manure and in the woodland were more permeable than the aggregates in other treatments. It was also found that compared to no-fertilization or fertilization with complete fertilizers, fertilizing without phosphorus over the past 20 years increased the porosity and permeability of the aggregates but not of the cores. Fertilization with inorganic fertilizers increased the tortuosity of the macropores in the cores but not of the intra-aggregate pores, compared to no-fertilization. Porosity-permeability relationship for aggregates unfertilized or fertilized with inorganic fertilisers followed a power law with R 2 > 0.8. In contrast, the permeability of the aggregates in farmyard manure and in the woodland trended differently as their porosity increased. The results also revealed that the transport ability of the aggregates and cores responded differently to carbon in that with soil carbon increasing, the permeability of the aggregates increased asymptotically while the permeability of the cores, especially its horizontal component, increased exponentially.

12.
Clin Infect Dis ; 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33388749

RESUMO

BACKGROUND: Children and older adults with coronavirus disease 2019 (COVID-19) display a distinct spectrum of disease severity yet the risk factors aren't well understood. We sought to examine the expression pattern of angiotensin-converting enzyme 2 (ACE2), the cell-entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the role of lung progenitor cells in children and older patients. METHODS: We retrospectively analysed clinical features in a cohort of 299 patients with COVID-19. The expression and distribution of ACE2 and lung progenitor cells were systematically examined using a combination of public single-cell RNA-seq datasets, lung biopsies, and ex vivo infection of lung tissues with SARS-CoV-2 pseudovirus in children and older adults. We also followed up patients who had recovered from COVID-19. RESULTS: Compared with children, older patients (> 50 yrs.) were more likely to develop into serious pneumonia with reduced lymphocytes and aberrant inflammatory response (p = 0.001). The expression level of ACE2 and lung progenitor cell markers were generally decreased in older patients. Notably, ACE2 positive cells were mainly distributed in the alveolar region, including SFTPC positive cells, but rarely in airway regions in the older adults (p < 0.01). The follow-up of discharged patients revealed a prolonged recovery from pneumonia in the older (p < 0.025). CONCLUSION: Compared to children, ACE2 positive cells are generally decreased in older adults and mainly presented in the lower pulmonary tract. The lung progenitor cells are also decreased. These risk factors may impact disease severity and recovery from pneumonia caused by SARS-Cov-2 infection in older patients.

13.
Cell Death Dis ; 11(12): 1075, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33323934

RESUMO

Mesenchymal stem cell (MSC)-based therapy has emerged as a novel strategy to treat many degenerative diseases. Accumulating evidence shows that the function of MSCs declines with age, thus limiting their regenerative capacity. Nonetheless, the underlying mechanisms that control MSC ageing are not well understood. We show that compared with bone marrow-MSCs (BM-MSCs) isolated from young and aged samples, NADH dehydrogenase (ubiquinone) iron-sulfur protein 6 (Ndufs6) is depressed in aged MSCs. Similar to that of Ndufs6 knockout (Ndufs6-/-) mice, MSCs exhibited a reduced self-renewal and differentiation capacity with a tendency to senescence in the presence of an increased p53/p21 level. Downregulation of Ndufs6 by siRNA also accelerated progression of wild-type BM-MSCs to an aged state. In contrast, replenishment of Ndufs6 in Ndufs6-/--BM-MSCs significantly rejuvenated senescent cells and restored their proliferative ability. Compared with BM-MSCs, Ndufs6-/--BM-MSCs displayed increased intracellular and mitochondrial reactive oxygen species (ROS), and decreased mitochondrial membrane potential. Treatment of Ndufs6-/--BM-MSCs with mitochondrial ROS inhibitor Mito-TEMPO notably reversed the cellular senescence and reduced the increased p53/p21 level. We provide direct evidence that impairment of mitochondrial Ndufs6 is a putative accelerator of adult stem cell ageing that is associated with excessive ROS accumulation and upregulation of p53/p21. It also indicates that manipulation of mitochondrial function is critical and can effectively protect adult stem cells against senescence.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Senescência Celular , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , NADH Desidrogenase/metabolismo , Células-Tronco Adultas/ultraestrutura , Animais , Células da Medula Óssea/metabolismo , Diferenciação Celular , Regulação para Baixo/genética , Técnicas de Silenciamento de Genes , Humanos , Células-Tronco Mesenquimais/ultraestrutura , Camundongos Endogâmicos C57BL , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/genética , NADH Desidrogenase/genética , Subunidades Proteicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
14.
Exp Ther Med ; 20(6): 278, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33200003

RESUMO

Bronchial thermoplasty (BT) is a treatment to reduce the airway smooth muscle mass by delivering radiofrequency thermal energy to the airways. BT is used in patients with severe asthma. The present study reported on cases of pneumothorax directly after BT and retrospectively analyzed early radiologic and bronchoscopic modifications after BT. The clinical data and radiologic and bronchoscopic findings of 12 patients with severe asthma who were subjected to BT between July 2014 and October 2017 were analyzed. A total of 33 chest radiographs were collected within 18-24 h after BT. Radiological abnormalities were observed in 32 radiographs as atelectasis (53.1%), peribronchial consolidations (84.4%), pleural effusion (18.8%), effusion in oblique fissures (3.1%), pleural thickening (6.3%) and pneumothorax (3.1%). Of note, one patient suffered pneumothorax after the third BT session and underwent chest drain insertion, followed by mechanical ventilation at the intensive care unit and multiple bronchoscopic interventions, which revealed extensive phlegm plugs. A total of six patients with worsened symptoms and lobar atelectasis also required bronchoscopic intervention, which revealed that phlegm plugs occluded the bronchus in the treated lobe. No bronchoscopic intervention was required in the remaining five patients. During 16-30 days of follow-up, 95.7% of the findings on chest radiography were resolved. To the best of our knowledge, the present study reported the first case of pneumothorax following BT. Early radiologic modifications such as atelectasis and peribronchial consolidations appear common after BT. However, whether bronchoscopic intervention is required for atelectasis following BT warrants further investigation. Of note, BT should be audited and recorded in detail to ideally contribute to a framework of clinical trials to improve risk-benefit evaluations and the selection of patients likely to benefit from treatment.

15.
J Phys Chem Lett ; 11(20): 8483-8489, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32966089

RESUMO

The interaction between photogenerated carriers with lattice vibrations plays a fundamental role in the nonradiative recombination and charge-transfer processes occurring in photocatalysis and photovoltaics. Here, we employ Raman spectroscopy to investigate the electron-phonon interaction in ternary layered Cu2MoS4 nanoflakes. Multiphonon Raman scattering with up to fourth-order longitudinal optical (LO) overtones is observed under above-band gap excitation, indicating a strong electron-phonon coupling (EPC) that could be described by the cascade model. The Huang-Rhys factor was derived to characterize the strength of EPC and was found to be increasing with decreasing temperature. First-principles calculations of lattice dynamics and electron-phonon matrix elements suggest that the strong EPC in Cu2MoS4 is dominated by Fröhlich coupling between electron and the electric fields, which is induced by the localized phonon mode originating from a flat phonon branch. Our findings facilitate the understanding of electron-phonon interaction in 2D ternary Cu2MoS4 and pave the way for developing and optimizing optoelectronic devices.

16.
Environ Pollut ; 267: 115452, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32871485

RESUMO

Adding exogenous low-molecular weight organic acids is an effective technique to improve phytoremediation of Cd-contaminated soil and has been well documented, but how acid application rate affects remediation efficiency and its underlying limiting factors remains elusive. We investigated this using pot experiments with rapeseed (Brassica napus L.) as the model plant. Plastic pots packed with a sandy loam contaminated by Cd at 4.838 mg/kg were amended with acetic acid, oxalic acid, citric acid, malic acid and tartaric acid, respectively, at an application rate gradient varying from 0.0 to 12.0 mmol/kg. Plants in each pot were harvested after growing for five months, and we then measured the exchangeable, carbonate, Fe-Mn oxide, organic and residual Cd in the rhizosphere, as well as Cd in both roots and shoots. The results showed that all organic acids improved plant uptake of Cd and, compared with the control without acid addition, they could improve Cd uptake by more than 100%. The enhanced Cd extraction was due to the increase in exchangeable Cd in the rhizosphere. Plant Cd was weakly correlated to the amount of Cd lost from a unit volume of the rhizosphere due to root extraction (R2 = 0.06), but a good negative correlation was found between them after normalizing the lost Cd by root biomass (R2 = 0.36). Mass balance analysis revealed that the average Cd content in soil (rhizosphere and bulk soils combined) was much higher than the Cd content in the rhizosphere, and the improved Cd mobility after acid addition was thus due to the increased chelation. As diffusion of ligands in water is one order in magnitude smaller than diffusion of Cd ions, our results suggested that Cd migration from the bulk soil into the rhizosphere was a major factor limiting Cd phytoextraction by rapeseed after adding the exogenous organic acids.


Assuntos
Brassica napus , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Raízes de Plantas/química , Rizosfera , Solo , Poluentes do Solo/análise
17.
Sci Rep ; 10(1): 10649, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32606383

RESUMO

We use a unique set of terrestrial experiments to demonstrate how soil management practises result in emergence of distinct associations between physical structure and biological functions. These associations have a significant effect on the flux, resilience and efficiency of nutrient delivery to plants (including water). Physical structure, determining the air-water balance in soil as well as transport rates, is influenced by nutrient and physical interventions. Contrasting emergent soil structures exert selective pressures upon the microbiome metagenome. These selective pressures are associated with the quality of organic carbon inputs, the prevalence of anaerobic microsites and delivery of nutrients to microorganisms attached to soil surfaces. This variety results in distinctive gene assemblages characterising each state. The nature of the interactions provide evidence that soil behaves as an extended composite phenotype of the resident microbiome, responsive to the input and turnover of plant-derived organic carbon. We provide new evidence supporting the theory that soil-microbe systems are self-organising states with organic carbon acting as a critical determining parameter. This perspective leads us to propose carbon flux, rather than soil organic carbon content as the critical factor in soil systems, and we present evidence to support this view.


Assuntos
Metagenoma , Microbiota , Microbiologia do Solo , Solo/química , Ciclo do Carbono , Fenótipo
18.
Sci Total Environ ; 743: 140644, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653710

RESUMO

The association of the cation and anion of ionic liquids (ILs) dominates the absorbability of ILs by activated carbon (AC). Nevertheless, the mechanism behind the role of ion-pairs is largely unknown. In this study, the adsorption of a series of imidazolium derivative-based ILs by AC was involved in response to the octanol-water partition coefficient (KOW), hydrogen bonding acidity (α), ion-pair binding constants (KIP), binding energy of ion-pairs (Ebinding) and density functional theory (DFT) calculation of ILs. A significant positive correlation between lg KOW and Kd and between KIP and lg KOW was observed (p < 0.05). However, both Ebinding and α was inversely proportional to KIP. Hence, the substitution of oxygen-containing functional groups, such as carboxyethyl, 1-methoxyethyl, and 1-(ethoxycarbonyl)methyl, on imidazolium ring enhanced the hydrogen bond interaction with water molecules and then weakened the binding of imidazolium cation and [NTf2]-, thereby reducing the adsorption of ILs to AC. DFT calculation further revealed that the polar substitution improved the electron density and electronegativity of imidazolium skeleton. By contrast, the ILs functionalized with non-polar groups (e.g., butyl, allyl, and benzyl) generally displayed high KIP values and low α values. Consequently, the formation of hydrogen bond between the oxygen-containing functional groups of IL cation and water would facilitate the dissociation of IL ion-pairs and then decrease the adsorption of ILs on AC.

19.
Trends Pharmacol Sci ; 41(8): 544-556, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32564900

RESUMO

Hormesis is a generalizable dose-response relationship characterized by low-dose stimulation and high-dose inhibition. Despite debate over this biphasic dose-response curve, hormesis is challenging central beliefs in the evaluation of chemicals or drugs and has influenced biological model selection, concentration range, study design, and hypothesis testing. We integrate the traditional Chinese philosophy - Yin/Yang doctrine - into the representation of the Western hormetic dose-response relationship and review the Yin/Yang historical philosophy contained in the hormesis concept, aiming to promote general acceptance and wider applications of hormesis. We suggest that the Yin/Yang doctrine embodies the hormetic dose-response, including the relationship between the opposing components, curve shape, and time-dependence, and may afford insights that clarify the hormetic dose-response relationship in toxicology and pharmacology.


Assuntos
Hormese , Modelos Biológicos , Relação Dose-Resposta a Droga , Humanos
20.
Front Neurosci ; 14: 187, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32265625

RESUMO

Cerebellar ataxias (CAs) consist of a heterogeneous group of neurodegenerative diseases hallmarked by motor deficits and deterioration of the cerebellum and its associated circuitries. Neuroinflammatory responses are present in CA brain, but how neuroinflammation may contribute to CA pathogenesis remain unresolved. Here, we investigate whether transforming growth factor (TGF)-ß1, which possesses anti-inflammatory and neuroprotective properties, can ameliorate the microglia-mediated neuroinflammation and thereby alleviate neurodegeneration in CA. In the current study, we administered TGF-ß1 via the intracerebroventricle (ICV) in CA model rats, by intraperitoneal injection of 3-acetylpyridine (3-AP), to reveal the neuroprotective role of TGF-ß1. The TGF-ß1 administration after 3-AP injection ameliorated motor impairments and reduced the calbindin-positive neuron loss and apoptosis in the brain stem and cerebellum. Meanwhile, 3-AP induced microglial activation and inflammatory responses in vivo, which were determined by morphological alteration and an increase in expression of CD11b, enhancement of percentage of CD40 + and CD86 + microglial cells, upregulation of pro-inflammatory mediators, tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, and a downregulation of neurotrophic factor, insulin-like growth factor (IGF)-1 in the brain stem and cerebellum. TGF-ß1 treatment significantly prevented all the changes caused by 3-AP. In addition, in vitro experiments, TGF-ß1 directly attenuated 3-AP-induced microglial activation and inflammatory responses in primary cultures. Purkinje cell exposure to supernatants of primary microglia that had been treated with TGF-ß1 reduced neuronal loss and apoptosis induced by 3-AP-treated microglial supernatants. Furthermore, the protective effect was similar to those treated with TNF-α-neutralizing antibody. These findings suggest that TGF-ß1 protects against neurodegeneration in 3-AP-induced CA rats via inhibiting microglial activation and at least partly TNF-α release.

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