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1.
Br J Pharmacol ; 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33068011

RESUMO

BACKGROUND AND PURPOSE: Acute kidney injury (AKI) is a common and critical illness, resulting in severe morbidity and a high mortality. There is a considerable interest in identifying novel molecular targets for management of AKI. Here, we investigated the potential role of the circadian clock components Rev-erbα/ß in regulation of ferroptosis and AKI. EXPERIMENTAL APPROACH: AKI model was established by treating mice with folic acid (FA). Regulatory effects of Rev-erbα/ß on AKI and ferroptosis were determined using single gene knockout (Rev-erbα-/- and Rev-erbß-/- ) mice, incomplete double knockout (icDKO, Rev-erbα+/- Rev-erbß-/- ) mice, and cells with erastin-induced ferroptosis. Targeted antagonism of Rev-erbα/ß to alleviate AKI and ferroptosis was assessed using the small-molecule antagonist SR8278. Transcriptional gene regulation was investigated using luciferase reporter, mobility shift, and chromatin immunoprecipitation assays. KEY RESULTS: Loss of Rev-erbα or Rev-erbß reduced the sensitivity of mice to FA-induced AKI and eliminated the circadian time-dependency in disease severity. This coincided with less extensive ferroptosis, a main cause of FA-induced AKI. Moreover, icDKO mice were more resistant to FA-induced AKI and ferroptosis as compared to single gene knockout mice. Supporting this, targeting Rev-erbα/ß by SR8278 attenuated ferroptosis to ameliorate FA-induced AKI in mice. Mechanistically, Rev-erbα/ß promoted ferroptosis by repressing the transcription of Slc7a11 and HO-1 (two ferroptosis-inhibitory genes) via direct binding to a RORE cis-element. CONCLUSION AND IMPLICATIONS: Targeted inhibition of Rev-erbα/ß limits ferroptosis to ameliorate FA-induced AKI in mice. The findings may have implications for improved understanding of circadian clock-controlled ferroptosis and for formulating new strategies to treat AKI.

2.
BMC Plant Biol ; 20(1): 462, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032521

RESUMO

BACKGROUND: Soil salinization and alkalinization are the main factors that affect the agricultural productivity. Evaluating the persistence of the compound material applied in field soils is an important part of the regulation of the responses of cotton to saline and alkaline stresses. RESULT: To determine the molecular effects of compound material on the cotton's responses to saline stress and alkaline stress, cotton was planted in the salinized soil (NaCl 8 g kg- 1) and alkalized soil (Na2CO3 8 g kg- 1) after application of the compound material, and ion content, physiological characteristics, and transcription of new cotton leaves at flowering and boll-forming stage were analyzed. The results showed that compared with saline stress, alkaline stress increased the contents of Na+, K+, SOD, and MDA in leaves. The application of the compound material reduced the content of Na+ but increased the K+/Na+ ratio, the activities of SOD, POD, and CAT, and REC. Transcriptome analysis revealed that after the application of the compound material, the Na+/H+ exchanger gene in cotton leaves was down-regulated, while the K+ transporter, K+ channel, and POD genes were up-regulated. Besides, the down-regulation of genes related to lignin synthesis in phenylalanine biosynthesis pathway had a close relationship with the ion content and physiological characteristics in leaves. The quantitative analysis with PCR proved the reliability of the results of RNA sequencing. CONCLUSION: These findings suggest that the compound material alleviated saline stress and alkaline stress on cotton leaves by regulating candidate genes in key biological pathways, which improves our understanding of the molecular mechanism of the compound material regulating the responses of cotton to saline stress and alkaline stress.

4.
Sci Adv ; 6(41)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33028526

RESUMO

Understanding the regime shifts of social-ecological systems (SES) and their local and spillover effects over a long time frame is important for future sustainability. We provide a perspective of processes unfolding over time to identify the regime shifts of a SES based on changes in the relationships between SES components while also addressing their drivers and local and spillover effects. The applicability of this approach has been demonstrated by analyzing the evolution over the past 1000 years of the SES in China's Loess Plateau (LP). Five evolutionary phases were identified: "fast expansion of cultivation," "slow expansion of cultivation," "landscape engineering for higher production," "transition from cultivation to ecological conservation," and "revegetation for environment." Our study establishes empirical links between the state (phase) of a SES to its drivers and effects. Lessons of single-goal driven and locally focused SES management in the LP, which did not consider these links, have important implications to long-term planning and policy formulation of SES.

5.
Sci Adv ; 6(42)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33055157

RESUMO

We uncover a cycling and NF-κB-driven lncRNA (named Lnc-UC) that epigenetically modifies transcription of circadian clock gene Rev-erbα, thereby linking circadian clock to colitis. Cycling expression of Lnc-UC is generated by the central clock protein Bmal1 via an E-box element. NF-κB activation in experimental colitis transcriptionally drives Lnc-UC through direct binding to two κB sites. Lnc-UC ablation disrupts colonic expressions of clock genes in mice; particularly, Rev-erbα is down-regulated and its diurnal rhythm is blunted. Consistently, Lnc-UC promotes expression of Rev-erbα (a known dual NF-κB/Nlrp3 repressor) to inactivate NF-κB signaling and Nlrp3 inflammasome in macrophages. Furthermore, Lnc-UC ablation sensitizes mice to experimental colitis and abolishes the diurnal rhythmicity in disease severity. Mechanistically, Lnc-UC physically interacts with Cbx1 protein to reduce its gene silencing activity via H3K9me3, thereby enhancing Rev-erbα transcription and expression. In addition, we identify a human Lnc-UC that has potential to promote Rev-erbα expression and restrain inflammations.

6.
Sci Total Environ ; 755(Pt 2): 142708, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33049528

RESUMO

Alkaline soils are widely distributed around the world. During the mining and transportation processes galena may be exposed to the alkaline soils. Weathering of galena may lead to the formation of different lead phases having higher bio-accessibility than galena, and thereby increasing the mobility and toxicity of lead. In this study, electrochemical techniques and Raman spectroscopic measurements were used for the evaluation of the interfacial processes that are involved in the galena weathering under the conditions of simulated saline soil and meadow soil solutions. The results showed that the release of Pb2+ and S0 took place during initial stage of the oxidation. Thereafter, further transformation to anglesite would take place, even leading to the transformation to ß-PbO and α-PbO at higher temperatures. Galena weathering prone to saline soil than that in meadow soil, and has a faster weathering rate in the saline soil at same ambient temperature. Higher temperatures was found to promote the weathering of galena, and the rate constant for the release of Pb (II) was approximate 10-9 to 10-8 mol∙m-2∙s-1, while surface reaction was found to control the weathering kinetics. Based on the surface characterization and evaluation of the thermodynamic and kinetic parameters, the weathering mechanism of galena in the alkaline soil and its environmental implications was suggested.

7.
Cell Discov ; 6: 69, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33083004

RESUMO

As an early type of lung adenocarcinoma, ground glass nodule (GGN) has been detected increasingly and now accounts for most lung cancer outpatients. GGN has a satisfactory prognosis and its characteristics are quite different from solid adenocarcinoma (SADC). We compared the GGN adenocarcinoma (GGN-ADC) with SADC using the single-cell RNA sequencing (scRNA-seq) to fully understand GGNs. The tumor samples of five patients with lung GGN-ADCs and five with SADCs underwent surgery were digested to a single-cell suspension and analyzed using 10× Genomic scRNA-seq techniques. We obtained 60,459 cells and then classified them as eight cell types, including cancer cells, endothelial cells, fibroblasts, T cells, B cells, Nature killer cells, mast cells, and myeloid cells. We provided a comprehensive description of the cancer cells and stromal cells. We found that the signaling pathways related to cell proliferation were downregulated in GGN-ADC cancer cells, and stromal cells had different effects in GGN-ADC and SADC based on the analyses of scRNA-seq results. In GGN-ADC, the signaling pathways of angiogenesis were downregulated, fibroblasts expressed low levels of some collagens, and immune cells were more activated. Furthermore, we used flow cytometry to isolate the cancer cells and T cells in 12 GGN-ADC samples and in an equal number of SADC samples, including CD4+ T and CD8+ T cells, and validated the expression of key molecules by quantitative real-time polymerase chain reaction analyses. Through comprehensive analyses of cell phenotypes in GGNs, we provide deep insights into lung carcinogenesis that will be beneficial in lung cancer prevention and therapy.

8.
Iran J Public Health ; 49(8): 1476-1484, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33083324

RESUMO

Background: The aim of this study was to investigate the overall impact of PM2.5, PM10, NO2, SO2, CO, and O3 on the admission of cardiovascular and cerebrovascular disease. Methods: We collected data on cardiovascular and cerebrovascular disease admissions from two hospitals in Shenyang Liaoning, China from Jan 2014 to Dec 2017, as well as daily measurements of six pollutants at 11 sites in Shenyang. The generalized additive model was used to assess the association between daily contaminants and admission to cardiovascular and cerebrovascular disease. Results: The single-contamination model showed a significant correlation between NO2, O3, PM10 and cardiovascular and cerebrovascular diseases at lag0 day. Air pollutants had lag effects on different gender groups. Excess relative risks (ERs) associated with a 10 µg/m3 increase were 1.522(1.057, 1.988) on lag02 for NO2, 0.547% (0.367%, 0.728%), 0.133% (0.061%, 0.205%) on lag3 for O3 and PM10. The dual pollutant model showed that the effects of NO2, O3, and PM10 after adjusting the influence of other pollutants were still statistically significant. Conclusion: Short-term exposure to ambient air pollution (NO2, O3, and PM10) may be associated with an increased risk of daily cardiovascular and cerebrovascular admission, which may provide reliable evidence for further understanding of the potential adverse effects of air pollution on cardiovascular and cerebrovascular diseases.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33074646

RESUMO

Because of their high reversible capacity and wide operation voltage window, P2-type layered transition metal oxides are considered as one type of potential cathode candidate for sodium-ion batteries. However, they still suffer from low kinetics, phase degeneration, and ambiguous mechanism of Na+ diffusion. Here, we synthesized a P2-type Na0.6Li0.07Mn0.66Co0.17Ni0.17O2 with a high Na+ diffusion performance by sintering a nanoplate-structural precursor with alkali metal salt and proposed a possible mechanism for improving Na+ diffusion. The as-prepared P2-type layered oxide presents a quasi-hexagon shape and demonstrates a discharge capacity of 87 mAh g-1 at a current density of 875 mA g-1 (5 C rate), twice that of the sample synthesized from a non-nanoplate particle precursor. Rietveld refinement and results of X-ray photoelectron spectroscopy reveal the probable mechanism that the expanded interplanar spacing along the c-axis orientation would facilitate Na+ diffusion during Na+ intercalation/deintercalation processes, and the expanded interplanar spacing may arise from a high oxidation state of transition metal ions.

10.
JAMA Cardiol ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33031522

RESUMO

Importance: Sodium-glucose cotransporter 2 (SGLT2) inhibitors favorably affect cardiovascular (CV) and kidney outcomes; however, the consistency of outcomes across the class remains uncertain. Objective: To perform meta-analyses that assess the CV and kidney outcomes of all 4 available SGLT2 inhibitors in patients with type 2 diabetes. Data Sources: A systematic literature search was conducted in PubMed from January 1, 2015, to January 31, 2020. Study Selection: One hundred forty-five records were initially identified; 137 were excluded because of study design or topic of interest. As a result, a total of 6 randomized, placebo-controlled CV and kidney outcomes trials of SGLT2 inhibitors in patients with type 2 diabetes were identified, with contributory data from 9 publications. All analyses were conducted on the total patient population of these trials. Data Extraction and Synthesis: Standardized data search and abstraction were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. Data were analyzed using a fixed-effect model. Main Outcomes and Measures: Outcomes included time to the first event of (1) the composite of major adverse CV events of myocardial infarction, stroke, or CV death, and each component, (2) the composite of hospitalization for heart failure (HHF) or CV death (HHF/CV death) and each component, and (3) kidney composite outcomes. For outcomes in the overall trial populations and in selected subgroups, hazard ratios (HRs) and 95% CIs were pooled and meta-analyzed across trials. Results: Data from 6 trials comprised 46 969 unique patients with type 2 diabetes, including 31 116 (66.2%) with atherosclerotic CV disease. The mean (SD) age of all trial participants was 63.7 (7.9) years; 30 939 (65.9%) were men, and 36 849 (78.5%) were White. The median number of participants per trial was 8246 (range, 4401-17 160). Overall, SGLT2 inhibitors were associated with a reduced risk of major adverse CV events (HR, 0.90; 95% CI, 0.85-0.95; Q statistic, P = .27), HHF/CV death (HR, 0.78; 95% CI, 0.73-0.84; Q statistic, P = .09), and kidney outcomes (HR, 0.62; 95% CI, 0.56-0.70; Q statistic, P = .09), with no significant heterogeneity of associations with outcome. Associated risk reduction for HHF was consistent across the trials (HR, 0.68; 95% CI, 0.61-0.76; I2 = 0.0%), whereas significant heterogeneity of associations with outcome was observed for CV death (HR, 0.85; 95% CI, 0.78-0.93; Q statistic, P = .02; I2 = 64.3%). The presence or absence of atherosclerotic CV disease did not modify the association with outcomes for major adverse CV events (HR, 0.89; 95% CI, 0.84-0.95 and HR, 0.94; 95% CI, 0.83-1.07, respectively; P = .63 for interaction), with similar absence of associations with outcome modification by prevalent atherosclerotic CV disease for HHF/CV death (P = .62 for interaction), HHF (P = .26 for interaction), or kidney outcomes (P = .73 for interaction). Conclusions and Relevance: In this meta-analysis, SGLT2 inhibitors were associated with a reduced risk of major adverse CV events; in addition, results suggest significant heterogeneity in associations with CV death. The largest benefit across the class was for an associated reduction in risk for HHF and kidney outcomes, with benefits for HHF risk being the most consistent observation across the trials.

11.
BMC Cancer ; 20(1): 988, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046024

RESUMO

BACKGROUND: Increasing studies have demonstrated that activated platelets play an essential role in tumour progression. However, the level and prognostic role of platelet indices in chordoma patients remain unclear. The aim of the current study was to characterize the prognostic performance of platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW) in skull base chordoma patients. METHODS: 187 primary skull base chordoma patients between January 2008 and September 2014 were enrolled in this retrospective study. The optimal cut-off values were determined by X-tile software, and the correlations between PLT, MPV, PDW and clinicopathological features were further analysed. Kaplan-Meier curve and Cox regression analysis were used for survival analysis. RESULTS: The values of preoperative PTL, MPV and PDW ranged from 104 to 501 × 109/L, 6.7 to 14.2 fl, and 7.8 to 26.2%, respectively. Elevated PLT was associated with larger tumour volume (p = 0.002). Kaplan-Meier survival analysis revealed that increased MPV and PDW were associated with shorter overall survival (p = 0.022 and 0.008, respectively). Importantly, multivariate Cox analysis demonstrated that elevated PDW was an independent unfavourable predictive factor for overall survival (hazard ratio (HR), 2.154, 95% confidence interval (CI), 1.258-3.688, p = 0.005). CONCLUSIONS: Our data show that elevated MPV and PDW are associated with poor outcomes in skull base chordoma and that PDW may be helpful to identify patients with high risk.

12.
Medicine (Baltimore) ; 99(37): e21663, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925713

RESUMO

BACKGROUND: The incidence of heart failure with normal ejection fraction (HFNEF) is increasing yearly, accounting for approximately half of all heart failure cases. Even after standardized treatment, the patient's prognosis is not good. Therefore, it is necessary to explore new treatment methods for HFNEF. Yangyin Shuxin Decoction, a traditional Chinese medicine prescription from our clinical experience in the treatment of HFNEF, has a potential cardioprotective effect. Preliminary clinical trials have shown that this prescription can improve the quality of life of HFNEF. This prompted us to use more objective indicators to further evaluate whether Yangyin Shuxin Decoction can improve the exercise capacity in HENEF patients. METHODS: This is a single-center parallel randomized controlled trial. The 64 patients who met the inclusion criteria were from the Cardiovascular Clinic. They will be randomly assigned to the treatment group (Yangying Shuxin Decoction combined with standard treatment) or the control group (standard treatment) according to the ratio of 1:1. The course of treatment will be 2 weeks. Both groups were interviewed at the following time points: of at enrollment (V1), and week 2 (V2), week 4 (V3), week 8 (V4), and week 12 (V5) after enrollment. The primary indicator is the peak oxygen consumption (Peak VO2) of the cardiopulmonary exercise test (CPET). Secondary indicators include CPET indicators such as anaerobic threshold oxygen consumption, carbon dioxide ventilation equivalent slope, echocardiographic indicators such as the ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity(E/e'), left atrial volume index (LAVI), left ventricular mass index (LVMI), the peak velocity of tricuspid regurgitation (TR), B-type natriuretic peptide (BNP), New York Heart Association (NYHA) cardiac function grading, and so on. These indicators will be used to evaluate the effect of Yangyin Shuxin Decoction on exercise capacity in patients with HFNEF. DISCUSSION: At present, it is unclear whether the exercise capacity can be maintained after long-term use of Yangyin Shuxin Decoction. In this study, we will evaluate whether Yangyin Shuxin Decoction can improve the exercise capacity and quality of life of patients with HFNEF. This will provide an objective basis for the therapeutic effect of traditional Chinese medicine on HFNEF. TRIAL REGISTRATION: This study protocol has been listed in the Chinese Clinical Trial Registry (registration number: ChiCTR-IOR-17014206, http://www.chictr.org.cn/showproj.aspx?proj=24304) on December 28, 2017.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Volume Sistólico/fisiologia , Adulto , Idoso , Ecocardiografia , Teste de Esforço , Tolerância ao Exercício , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Síndrome , Resultado do Tratamento
13.
Sci Rep ; 10(1): 15407, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958799

RESUMO

The sarco/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) is responsible for calcium transport during excitation-contraction coupling and is essential for maintaining myocardial systolic/diastolic function and intracellular Ca2+ levels. Therefore, it is important to investigate mechanisms whereby luteolin modulates SERCA2a expression to attenuate myocardial ischemia/reperfusion injury. C57BL/6j mice were randomly divided into eight groups. The expression and activity of SERCA2a was measured to assess interactions between the SERCA2a promoter and the Sp1 transcription factor, and the regulatory effects of luteolin. We used serum LDH release, serum cardiac troponin I level, hemodynamic data, myocardial infarction size and apoptosis-related indices to measure SERCA2a cardio-protective effects of luteolin pretreatment. Sp1 binding to SERCA2a promoter under ischemia/reperfusion conditions in the presence or absence of luteolin was analyzed by chromatin immunoprecipitation. Our experimental results indicated that during myocardial ischemia/reperfusion injury, luteolin pretreatment upregulated the expression levels of SERCA2a and Sp1. Sp1 overexpression enhanced the expression of SERCA2a at the transcriptional level. Luteolin pretreatment reversed the expression of SERCA2a through the increased expression of Sp1. Moreover, we demonstrated that luteolin pretreatment appeared to exert myocardial protective effects by upregulating the transcriptional activity of SERCA2a, via Sp1. In conclusion, during myocardial ischemia/reperfusion, Sp1 appeared to downregulate the expression of SERCA2a. Luteolin pretreatment was shown to improve SERCA2a expression via the upregulation of Sp1 to attenuate myocardial ischemia/reperfusion injury.

14.
J Orthop Sci ; 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32950323

RESUMO

BACKGROUND: The Wahlquist system classifies tibial medial plateau fractures into three types based on the sagittal fracture line location, with type C at highest risk of complications. However, the injury mechanism of tibial medial plateau fractures, especially tibial rotation movement, remains unclear. The purpose of the present study was to determine the injury patterns of medial tibial plateau fractures using 3D model simulation and quantitative 3D measurements. METHODS: Seventy-eight consecutive AO/OTA type 41-B tibial plateau fractures were retrospectively analyzed using CT-based 3D models and quantitative 3D measurements. The knee posture at the moment of fracture occurrence was simulated, and various knee angles in the sagittal, coronal, and axial planes were measured to evaluate the mechanism of medial tibial plateau fracture. The mean valgus-varus, hyperextension-flexion, and internal-external rotation angles were determined, and the chi-square test was used for comparisons of categorical varus and valgus force data to determine the main force direction in Wahlquist type C fractures. RESULTS: Angle measurements in the coronal planes showed that 28 (35.9%) medial tibial plateau fractures resulted from a varus injury pattern, while 50 fractures (64.1%) resulted from a valgus pattern. Valgus force produced significantly more Wahlquist type C fractures (37 of 50 fractures) than varus force (2 of 28 fractures) (p < 0.05). There was no significant difference in the cases of patients with type C fractures between the tibial internal and external rotation injury patterns(P > 0.05). CONCLUSIONS: Valgus force was the cause of 64.1% of the medial tibia plateau fractures in the present cohort. Furthermore, valgus force produced more Wahlquist type C fractures than varus force. The present findings will help orthopedists understand the injury mechanism of the Wahlquist classification system, and will facilitate the identification of the common features of medial tibial plateau fractures induced by specific injury patterns.

15.
ACS Nano ; 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32935968

RESUMO

Anisotropic patchy particles with molecular precision are exquisite building blocks for constructing diverse meso-structures of high complexity. In this research, a library of molecular patchy clusters consisting of a collection of functional polyhedral oligomeric silsesquioxane cages with exact regio-configuration and composition were prepared through a robust and modular approach. By meticulously tuning the composition, molecular symmetry, and other parameters, these patchy clusters could assemble into diverse nanostructures, including unconventional complex spherical phases (i.e., Frank-Kasper σ phase and dodecagonal quasicrystalline phase). As the size of the hydrophilic patch expands, a transition sequence from disorder to hexagonally packed cylinders and then to double gyroids was recorded, corresponding to a progressive decrease of interfacial curvature. On the other hand, regioisomers with the same composition but different regio-configuration adopt similar molecular packing but varied phase stability, as a result of the local self-sorting process to alleviate excess unfavorable interfacial contact. These precisely defined molecular patchy clusters provide a model system for a general understanding of the hierarchical structure formation and evolution based on anisotropic spherical building blocks at the nanoscale.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32968899

RESUMO

The binding interaction between emerging pollutant polyvinyl chloride microplastics (PVC MPs) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy, resonance scattering spectroscopy (RLS), UV-visible (UV-vis) absorption spectroscopy, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. Fluorescence results revealed that the fluorescence quenching of BSA induced by PVC MPs was originated from the formation of BSA-PVC complex in static quenching mode. According to Stern-Volmer equation, the binding constants (Ka) between PVC MPs and BSA at different temperatures were obtained, and the number of binding sites was 1.62. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS), and free energy change (ΔG) were calculated to be - 41.77 kJ mol-1, 43.17 J mol-1 K-1, and - 54.63 kJ mol-1 via Van't Hoff equation, indicating electrostatic interaction played a key role in the formation of BSA-PVC complex spontaneously. In addition, the alterations of microenvironment and secondary structure in BSA induced by PVC MPs were further confirmed by synchronous fluorescence spectra, UV-vis, FT-IR, and CD. This work not only provides further information for better understanding the binding interaction of PVC MPs with BSA, but also elucidates the potential biological toxicity of MPs at a molecular level.

17.
Luminescence ; 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978869

RESUMO

Artificial light harvesting systems have attracted a great interesting in biological photosynthesis and photo-voltaic devices areas due to its unique structure, easier purification, low-cost, and convenient process ability. Here, two dendritic molecules based on triphenylamine and naphthalimide have been designed and synthesized, their structures have been confirmed by 1 H NMR, ESI-MS and high resolution mass spectrometry. In these molecules, triphenylamine units perform as the electron donor moiety, naphthalimide units perform as the electron acceptor, the obvious quenched fluorescence intensity and considerably shortened lifetime of the dendritic molecules combined with the molecular frontier orbital energy levels proved that the dendritic molecules not only are good candidates as hole-transporting materials but also are two excellent photo-induced electron transfer materials. Therefore, it is believed that these dendritic molecules have potential application value in the photo-voltaic devices areas.

18.
IEEE Trans Med Imaging ; PP2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32956051

RESUMO

Accurate segmentation of the prostate and organs at risk (OARs, e.g., bladder and rectum) in male pelvic CT images is a critical step for prostate cancer radiotherapy. Unfortunately, the unclear organ boundary and large shape variation make the segmentation task very challenging. Previous studies usually used representations defined directly on unclear boundaries as context information to guide segmentation. Those boundary representations may not be so discriminative, resulting in limited performance improvement. To this end, we propose a novel boundary coding network (BCnet) to learn a discriminative representation for organ boundary and use it as the context information to guide the segmentation. Specifically, we design a two-stage learning strategy in the proposed BCnet: 1) Boundary coding representation learning. Two sub-networks under the supervision of the dilation and erosion masks transformed from the manually delineated organ mask are first separately trained to learn the spatial-semantic context near the organ boundary. Then we encode the organ boundary based on the predictions of these two sub-networks and design a multi-atlas based refinement strategy by transferring the knowledge from training data to inference. 2) Organ segmentation. The boundary coding representation as context information, in addition to the image patches, are used to train the final segmentation network. Experimental results on a large and diverse male pelvic CT dataset show that our method achieves superior performance compared with several state-of-the-art methods.

19.
Int J Artif Organs ; : 391398820959344, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32957840

RESUMO

The blood pump is a medical device used to assist or replace the diseased heart. Research on the structure of blood pumps has been committed to achieving better hemolysis and hydraulic performance. The purpose of this study was to find some effective ways to improve design methods and hydraulic structures. The research contents of improvement include: (1) improved blade streamline design method; (2) conical impeller hub; (3) additional auxiliary blades. Characteristic analysis and parameter design were carried out on the above three aspects. The methods used in this study included Dynamics (CFD) simulation, hydraulic experiments, and Particle Image Velocimetry (PIV) experiments. The results showed that this improved streamline design method could improve the distortion of blades and ensure a smaller impeller length. And, in the enhanced design of the hub, it is designed to be conical with inlet and outlet diameters of 7.5 and 12.8 mm, respectively. Furthermore, the auxiliary blades between the main blades are analyzed and designed. The results have the best performance optimization effect when the length of the auxiliary blades is 55% of the main blades. In general, the structural improvements in this study achieved the effect of improving hydraulic performance and avoiding increased hemolysis. These methods can be considered as an effective means of improving blood pump performance.

20.
Chemistry ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32901978

RESUMO

Uranyl cation, as a powerful photocatalyst, at present, is seriously delayed compared to the development of its fundamental and structural chemistry. However, the characteristic of highly oxidative capability in the excited state {[UO 2 ] 2+* (+ 2.6 V vs. SHE) combined with blue light (hv 380-500 nm) absorption and a long-lived fluorescence lifetime up to microseconds have revealed that uranyl cation approaches an ideal photocatalyst for visible-light-drvien organic transformations. Described herein is a successful utilization of uranyl nitrate photocatalyst which enables C(sp 3 )-H activation and C-C bond formation through hydrogen atom transfer (HAT) under blue light irradiation. In particular, this operationally simple scenario provides an appropriate approach to synthesize diverse and valuable diarylmethane motifs. Mechanistic studies and DFT calculations provide insights into detailed mechanism of the photoinduced HAT pathway. The current research is suggestive of a general platform that could popularize promising uranyl photocatalytic performance.

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