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1.
Artigo em Inglês | MEDLINE | ID: mdl-32378411

RESUMO

Developing highly efficient transition metal dichalcogenide electrocatalysts would be significantly beneficial for the electrocatalytic hydrogen evolution reaction (HER) from water splitting. Herein, we reported novel ultrathin tantalum disulfide nanosheets (TaS2 NSs) prepared by electrochemically exfoliating bulk TaS2 with an alternating voltage in an acidic electrolyte. The obtained TaS2 NS electrocatalyst possessed an ultrathin structure with a lateral size of 2 µm and a thickness of ∼3 nm. Owing to the unique 2D structure, the achieved TaS2 NSs displayed remarkable electrocatalytic activity toward the HER by a small overpotential of 197 mV at 10 mA cm-2 and a small Tafel slope of 100 mV dec-1 in acidic solution, much lower than those of TaS2 (>547 mV and 216 mV dec-1, respectively) and other reported TaS2-based HER electrocatalysts. Furthermore, highly efficient full water splitting could be realized with two electrodes in which TaS2 NSs acted as the cathode while Ir/C served as the anode, with help of two AA size batteries or solar cells. By replacing the oxygen evolution reaction with the urea oxidation reaction (UOR), bifunctional TaS2 NSs enabled an energy-effective HER process in the cathode and UOR process in the anode with decreased applied potential.

2.
Int J Cardiol ; 2020 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-32376417

RESUMO

Patient delay is a worldwide unsolved problem in ST-segment elevated myocardial infarction (STEMI). An accurate warning system based on electrocardiogram (ECG) may be a solution for this problem, and artificial intelligence (AI) may offer a path to improve its accuracy and efficiency. In the present study, an AI-based STEMI autodiagnosis algorithm was developed using a dataset of 667 STEMI ECGs and 7571 control ECGs. The algorithm for detecting STEMI proposed in the present study achieved an area under the receiver operating curve (AUC) of 0.9954 (95% CI, 0.9885 to 1) with sensitivity (recall), specificity, accuracy, precision and F1 scores of 96.75%, 99.20%, 99.01%, 90.86% and 0.9372 respectively, in the external evaluation. In a comparative test with cardiologists, the algorithm had an AUC of 0.9740 (95% CI, 0.9419 to 1), and its sensitivity (recall), specificity, accuracy, precision, and F1 score were 90%, 98% and 94%, 97.82% and 0.9375 respectively, while the medical doctors had sensitivity (recall), specificity, accuracy, precision and F1 score of 71.73%, 89.33%, 80.53%, 87.05% and 0.8817 respectively. This study developed an AI-based, cardiologist-level algorithm for identifying STEMI.

3.
PLoS One ; 15(4): e0231098, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32315304

RESUMO

Trichogramma leucaniae is believed to be an efficient biological control agent for controlling the soybean pod borer [SPB; Leguminivora glycinivorella]. The large eggs of Chinese oak silkworm, Antheraea pernyi, are one of the best alternative host for mass production of Trichogramma. However, they are considered poor host for the growth and development of T. leucaniae. Here, we determine the feasibility of successive rearings of T. leucaniae on the large eggs for eight generations and evaluated their capacity of parasitizing SPB eggs of different ages. In the first four generations, the suitability of T. leucaniae reared on large eggs exhibited a significant increasing tendency and then decreased with the successive generations thereafter. The percentage of parasitized eggs and number of emerged adults per egg were increased from 40.0% and 10.8 adults/egg in F1 generation to 86.7% and 36.4 adults/egg in F4 generation respectively. In addition, T. leucaniae reared on A. pernyi for four generations significantly parasitized more SPB eggs regardless of egg age compared with those reared on Corcyra cephalonica eggs. These results provided useful information on the feasibility of mass production of T. leucaniae by reared for successive generations on A. pernyi large eggs.

4.
Aging (Albany NY) ; 12(8): 6558-6569, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32310825

RESUMO

Inflammation plays an essential role in the development of lumbar disc degeneration (LDD), although the exact effects of macrophage subtypes on LDD remain unclear. Based on previous studies, we hypothesized that M2-polarization of local macrophages and simultaneous suppression of their production of fibrotic transforming growth factor beta 1 (TGFß1) could inhibit progression of LDD. Thus, we applied an orthotopic injection of adeno-associated virus (AAV) carrying shRNA for DNA Methyltransferase 1 (DNMT1) and/or shRNA for TGFß1 under a macrophage-specific CD68 promoter to specifically target local macrophages in a mouse model for LDD. We found that shDNMT1 significantly reduced levels of the pro-inflammatory cytokines TNFα, IL-1ß and IL-6, significantly increased levels of the anti-inflammatory cytokines IL-4 and IL-10, significantly increased M2 macrophage polarization, significantly reduced cell apoptosis in the disc degeneration zone and significantly reduced LDD-associated pain. The anti-apoptotic and anti-pain effects were further strengthened by co-application of shTGFß1. Together, these data suggest that M2 polarization of macrophages induced by both epigenetic modulation and suppressed production and release of TGFß1 from polarized M2 macrophages, may have a demonstrable therapeutic effect on LDD.

5.
Mol Phylogenet Evol ; 149: 106838, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32304825

RESUMO

To investigate the diploid-polyploid relationships and the role of maternal progenitors in establishment of polyploid richness in Triticeae, 35 polyploids representing almost all genomic constitutions together with 48 diploid taxa representing 20 basic genomes in the tribe were analyzed. Phylogenomic reconstruction, genetic distance matrix, and nucleotide diversity patterns of plastome sequences indicated that (1) The maternal donor of the annual polyploid species with the U- and D-genome are related to extant Ae. umbellulata and Ae. tauschii, respectively. The maternal donor to the annual polyploid species with the S-, G-, and B-genome originated from the species of Sitopsis section of the genus Aegilops. The annual species with the Xe-containing polyploids were donated by Eremopyrum as the female parent; (2) Pseudoroegneria and Psathyrostachys were the maternal donor of perennial species with the St- and Ns-containing polyploids, respectively; (3) The Lophopyrum, Thinopyrum and Dasypyrum genomes contributed cytoplasm genome to Pseudoroegneria species as a result of incomplete lineage sorting and/or chloroplast captures, and these lineages were genetically transmitted to the St-containing polyploid species via polyploidization; (4) There is a reticulate relationship among the St-containing polyploid species. It can be suggested that genetic heterogeneity might associate with the richness of the polyploids in Triticeae.

6.
Artigo em Inglês | MEDLINE | ID: mdl-32186359

RESUMO

Developing low-cost and effective electrocatalysts for electrochemical reduction of CO2 (CO2ER) is critical to CO2 conversion and utilization. Herein, we report a novel two-dimensional (2D) confined electrocatalyst composed of core-shell structured tin oxide nanoparticles (NPs) encapsulated into N-doped carbon (NC) supported on electrochemically exfoliated graphene (SnO2⊃NC@EEG) prepared by in situ carbonization of a 2-methylimidazole/SnO2 complex@poly(vinyl pyrrolidone) (PVP)-modified EEG precursor. The SnO2 NPs with an average size of ∼10 nm are confined in the NC shells with a thickness of 0.7 nm derived from 2-methylimidazole. The resulting 2D confined electrocatalyst significantly enhances the CO2ER performance with a small onset potential of -0.45 V, and high Faradic efficiencies of 81.2 and 93.2% for HCOO- and C1 products at -1.2 V, respectively, which is far superior to other reported SnO2/carbon-based CO2ER hybrids. The superb CO2ER catalytic activity of the SnO2⊃NC@EEG has resulted from the positive effect of N dopants and a strong confinement effect, which significantly expedites the CO2 adsorption associated with charge transfer from the NC to SnO2 NPs during CO2ER electrocatalysis.

7.
Hum Reprod ; 35(3): 494-503, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32142584

RESUMO

STUDY QUESTION: Does lysine 2-hydroxyisobutyrylation, a newly identified protein posttranslational modification (PTM), occur in human sperm and affect human sperm function? SUMMARY ANSWER: Lysine 2-hydroxyisobutyrylation mainly occurs in human sperm tail proteins, and excessive lysine 2-hydroxyisobutyrylation affects human sperm motility. WHAT IS KNOWN ALREADY: PTM is regarded as an important pathway in regulating sperm function since mature sperm are almost transcriptionally silent. However, only phosphorylation was extensively studied in mature sperm to date. Lysine 2-hydroxyisobutyrylation, a newly characterised PTM, is broadly conserved in both eukaryotic and prokaryotic cells. Although histone lysine 2-hydroxyisobutyrylation has been shown to be associated with active gene expression in spermatogenic cells, the presence, regulatory elements and function of lysine 2-hydroxyisobutyrylation have not been characterised in mature sperm. STUDY DESIGN, SIZE, DURATION: Sperm samples were obtained from normozoospermic men and asthenozoospermic men who visited the reproductive medical centre at Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi, China, between May 2017 and November 2018. In total, 58 normozoospermic men and 65 asthenozoospermic men were recruited to participate in this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Lysine 2-hydroxyisobutyrylation was examined using immunoblotting and immunofluorescence assays using a previously qualified pan anti-lysine 2-hydroxyisobutyrylation antibody. The immunofluorescence assay was imaged using super-resolution structured illumination microscopy. Sperm viability was examined by using the eosin staining method, and sperm motility parameters were assessed by computer-assisted sperm analysis. Sperm penetration ability was determined by evaluating the ability of the sperm to penetrate a 1% (w/v) methylcellulose solution. The level of intracellular adenosine triphosphate (ATP) was detected using a rapid bioluminescent ATP assay kit. MAIN RESULTS AND THE ROLE OF CHANCE: Lysine 2-hydroxyisobutyrylation was present in several proteins (20-100 kDa) mainly located in the tail of human sperm. Sperm lysine 2-hydroxyisobutyrylation was derived from 2-hydroxyisobutyrate (2-Hib) and was regulated by acyltransferase P300 and nicotinamide adenine dinucleotide-dependent lysine deacylase sirtuins. Elevation of sperm lysine 2-hydroxyisobutyrylation by 2-Hib decreased total motility, progressive motility, penetration ability and ATP level of human sperm. Interestingly, the level of sperm lysine 2-hydroxyisobutyrylation was higher in asthenozoospermic men than that in normozoospermic men and was negatively correlated with the progressive motility of human sperm. Furthermore, high levels of lysine 2-hydroxyisobutyrylation in asthenozoospermic men accompanied decreased ATP levels. LIMITATIONS, REASONS FOR CAUTION: Although the present study indicated the involvement of sperm lysine 2-hydroxyisobutyrylation in regulating human sperm motility, the underlying mechanism needs to be further illustrated. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study provide insight into the novel role of lysine 2-hydroxyisobutyrylation in human sperm and suggest that abnormality of sperm lysine 2-hydroxyisobutyrylation may be one of the causes for asthenozoospermia. STUDY FUNDING/COMPETING INTEREST(S): National Natural Science Foundation of China (81771644 to T.L. and 81871207 to H.C.); Natural Science Foundation of Jiangxi province (20171ACB21006). The authors have no conflicts of interest to declare.

8.
J Adolesc ; 79: 247-257, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32007661

RESUMO

INTRODUCTION: Discrimination is detrimental for the development of ethnic minority adolescents' academic competence. To combat the negative effects of discrimination and promote academic success, it is important to understand the mechanisms underlying the association between discrimination and academic competence. Guided by the integrative model of ethnic minority children's development and the adapting cultural systems framework, this study examined whether a culture-specific factor, language brokering efficacy, mediated the relation between adolescents' perceived discrimination and their academic competence. METHOD: Data were drawn form a two-wave longitudinal study of 604 Mexican American adolescent language brokers residing in and around a metropolitan city in central Texas, USA (54% female; Mage = 12.5; SD = 1.0; 75% born in the U.S.). Path analyses were conducted to answer the research questions. RESULTS: The study revealed that the link between discrimination and academic competence was mediated by language brokering efficacy when translating for fathers and mothers, although the path from language brokering efficacy to academic competence was stronger when brokering for mothers. CONCLUSIONS: The results highlight the importance of incorporating ethnic minority children's adapting cultural experiences in linking the contextual influence with their developmental competence. Implications for interventions aiming to reduce the negative impacts of discrimination are also discussed.

9.
Dev Med Child Neurol ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32052421

RESUMO

AIM: To describe the cognitive development of children with neurofibromatosis type 1 (NF1) and plexiform neurofibromas, and identify predictors of cognitive development. METHOD: Participants included 88 children with NF1 and plexiform neurofibromas (50 males, 38 females, aged 6-18y, mean=12y, SD=3y 7mo) on a natural history study at the National Cancer Institute. Neuropsychological assessments (e.g. IQ, academic achievement, attention, and executive functioning) were administered three times over 6 years. RESULTS: Relative to normative peers, the total sample of children with NF1 and plexiform neurofibromas demonstrated significantly lower scores in most cognitive domains and decreasing z-scores over time in math, writing, inhibitory control, and working memory. Children who had parents with (vs without) NF1 were more likely to experience decreased z-scores in performance IQ, reading, writing, attention, and working memory. Higher (vs lower) parental education was related to higher levels of IQ, math, reading, and cognitive flexibility and a slower decrease in math z-scores. Children's sex and the number of NF1 disease-related complications were not related to most cognitive outcomes. INTERPRETATION: Children with NF1 and plexiform neurofibromas are at high risk for cognitive difficulties and declining z-scores in various domains of cognitive functioning over time. The findings highlight the need for a better understanding of the within-group differences in these children and their need for individualized educational plans. WHAT THIS PAPER ADDS: Math, writing, inhibitory control, and working memory scores decreased over time. The proportion of children with clinically significant cognitive deficits increased over time. Parental neurofibromatosis type 1 and low education were related to greater cognitive difficulties in children.

10.
Small ; : e1905223, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32049431

RESUMO

Designing elaborate nanostructures and engineering defects have been promising approaches to fabricate cost-efficient electrocatalysts toward overall water splitting. In this work, a controllable Prussian-blue-analogue-sacrificed strategy followed by an annealing process to harvest defect-rich Ni-Fe-doped K0.23 MnO2 cubic nanoflowers (Ni-Fe-K0.23 MnO2 CNFs-300) as highly active bifunctional catalysts for oxygen and hydrogen evolution reactions (OER and HER) is reported. Benefiting from many merits, including unique morphology, abundant defects, and doping effect, Ni-Fe-K0.23 MnO2 CNFs-300 shows the best electrocatalytic performances among currently reported Mn oxide-based electrocatalysts. This catalyst affords low overpotentials of 270 (320) mV at 10 (100) mA cm-2 for OER with a small Tafel slope of 42.3 mV dec-1 , while requiring overpotentials of 116 and 243 mV to attain 10 and 100 mA cm-2 for HER respectively. Moreover, Ni-Fe-K0.23 MnO2 CNFs-300 applied to overall water splitting exhibits a low cell voltage of 1.62 V at 10 mA cm-2 and excellent durability, even superior to the Pt/C||IrO2 cell at large current density. Density functional theory calculations further confirm that doping Ni and Fe into the crystal lattice of δ-MnO2 can not only reinforce the conductivity but also reduces the adsorption free-energy barriers on the active sites during OER and HER.

11.
Int J Cardiovasc Imaging ; 36(6): 1121-1132, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32078096

RESUMO

To investigate the potential effect of intracoronary administration of the glycoprotein IIb/IIIa inhibitor tirofiban on the microvascular obstruction (MVO) assessed by cardiac magnetic resonance (CMR) imaging compared to the intravenous route in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Two hundred eight patients were randomized into two groups (tirofiban i.v. and tirofiban i.c.). CMR was completed within 3-7 days after ST-segment-elevation myocardial infarction. One hundred thirty-two patients had a follow-up CMR at 6 months after discharge. The primary end point was the CMR measurements including myocardium strain, myocardial perfusion index, final infarct size, prevalence and extent of MVO, and the change of left ventricular end-diastolic volume (LVEDV) at six months follow-up. The second endpoint was major adverse cardiovascular events (composite of all-cause death, nonfatal reinfarction and congestive heart failure) in one year. The MVO prevalence and extent [56% versus 36%, p = 0.004; 2.08 (IQR: 1.18-5.07) g versus 1.68 (IQR: 0.30-3.28) g, p = 0.041] showed a significant difference between the intravenous and intracoronary groups. Global left ventricular peak longitudinal strain was significantly different in intracoronary groups compared to intravenous groups, - 12.5 [IQR: - 13.4 to - 10.9] versus - 12.3 [IQR: - 13.4 to - 10.4], respectively (P = 0.042). Infarcted myocardial perfusion index was significantly different in intracoronary groups compared to intravenous groups, 0.11 [IQR: 0.08 to 0.15] versus 0.09 [IQR: 0.07 to 0.14], respectively (P = 0.026). Intracoronary tirofiban was associated with a higher change in LVEDV compared with intravenous group (- 10.2% [IQR: - 13.7% to - 2.6%] versus 1.3% [IQR: - 5.6% to 6.1%], p < 0.001). Intracoronary tirofiban application showed no benefit on the occurrence of major adverse cardiovascular events during follow-up compared to intravenous administration. This CMR study in ST-segment-elevation myocardial infarction patients showed a benefit in MVO and left ventricular remodeling for intracoronary tirofiban administration compared to intravenous administration in patients undergoing PCI.

12.
Eur Radiol ; 30(5): 2525-2534, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32006167

RESUMO

OBJECTIVE: To investigate the effect of image quality of coronary CT angiography (CCTA) on the diagnostic performance of a machine learning-based CT-derived fractional flow reserve (FFRCT). METHODS: This nationwide retrospective study enrolled participants from 10 individual centers across China. FFRCT analysis was performed in 570 vessels in 437 patients. Invasive FFR and FFRCT values ≤ 0.80 were considered ischemia-specific. Four-score subjective assessment based on image quality and objective measurement of vessel enhancement was performed on a per-vessel basis. The effects of body mass index (BMI), sex, heart rate, and coronary calcium score on the diagnostic performance of FFRCT were studied. RESULTS: Among 570 vessels, 216 were considered ischemia-specific by invasive FFR and 198 by FFRCT. Sensitivity and specificity of FFRCT for detecting lesion-specific ischemia were 0.82 and 0.93, respectively. Area under the curve (AUC) of high-quality images (0.93, n = 159) was found to be superior to low-quality images (0.80, n = 92, p = 0.02). Objective image quality and heart rate were also associated with diagnostic performance of FFRCT, whereas there was no statistical difference in diagnostic performance among different BMI, sex, and calcium score groups (all p > 0.05, Bonferroni correction). CONCLUSIONS: This retrospective multicenter study supported the FFRCT as a noninvasive test in evaluating lesion-specific ischemia. Subjective image quality, vessel enhancement, and heart rate affect the diagnostic performance of FFRCT. KEY POINTS: • FFRCTcan be used to evaluate lesion-specific ischemia. • Poor image quality negatively affects the diagnostic performance of FFRCT. • CCTA with ≥ score 3, intracoronary enhancement degree of 300-400 HU, and heart rate below 70 bpm at scanning could be of great benefit to more accurate FFRCTanalysis.

13.
Adv Healthc Mater ; : e1901366, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31951109

RESUMO

Oncogenic transformation of mammary epithelial cells (MECs) is a critical step in epithelial-to-mesenchymal transition (EMT), but evidence also shows that MECs undergo EMT with increasing matrix stiffness; the interplay of genetic and environmental effects on EMT is not clear. To understand their combinatorial effects on EMT, premalignant MCF10A and isogenic Ras-transformed MCF10AT are cultured on polyacrylamide gels ranging from normal mammary stiffness, ≈150 Pa, to tumor stiffness, ≈5700 Pa. Though cells spread on stiff hydrogels independent of transformation, only 10AT cells exhibit heterogeneous spreading behavior on soft hydrogels. Within this mixed population, spread cells exhibit an elongated, mesenchymal-like morphology, disrupted localization of the basement membrane, and nuclear localization of the EMT transcription factor TWIST1. MCF10AT spreading is not driven by typical mechanosensitive pathways including YAP and TGF-ß or by myosin contraction. Rather, ERK activation induces spreading of MCF10AT cells on soft hydrogels and requires dynamic microtubules. These findings indicate the importance of oncogenic signals, and their hierarchy with substrate mechanics, in regulating MEC EMT.

14.
Jpn J Radiol ; 38(4): 374-381, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31989387

RESUMO

BACKGROUND: The purpose of this study is to investigate the performance of dual-layer detector spectral CT for iron deposition compared to magnetic resonance imaging (MRI) T2* imaging. METHODS: Thirty-one patients with a clinical history of myelodysplastic syndromes and aplastic anemia underwent liver and cardiac T2*-weighted unenhanced MRI on a three-tesla MRI scanner, and underwent unenhanced CT scan laterally on a 128-row spectral detector CT. R2* values of the liver, septal muscle, and paraspinal muscle were calculated. Attenuation differences (ΔH) in the liver and myocardium were calculated between the lower (50 keV) and higher (120 keV) energy levels. RESULTS: The liver and cardiac T2* values were 9.54 ± 5.63 ms and 21.41 ± 2.44 ms, respectively. The liver-to-muscle and myocardium-to-muscle T2* value ratios were 0.37 ± 0.23 and 0.79 ± 0.19, respectively. The liver and cardiac ΔH were - 1.13 ± 4.24 HU and 2.22 ± 4.41 HU, respectively. There was a strong linear correlation between the liver R2* and ΔH (r = - 0.832, P < 0.001), but weak correlation existed between the cardiac R2* and ΔH (P = 0.041). CONCLUSIONS: Dual-layer detector spectral unenhanced CT seemed to be equally valuable to MRI T2* imaging for evaluating liver iron overload.

15.
J Youth Adolesc ; 49(1): 335-351, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31236755

RESUMO

Language brokering is a special form of interpersonal communication that is affected by the cultural and relational settings in which it occurs. The current study explores whether parent-adolescent acculturation status may influence Mexican American adolescent language brokers' translation experiences, including brokering frequency and attitudes. Using data from a two-wave longitudinal study (Nwave1 = 604; Nwave2 = 483; Mwave1.age = 12.91; 54.3% female), latent profile analyses were conducted, resulting in four mother-adolescent acculturation profiles as well as three father-adolescent profiles. The adolescent integrated-parent (moderately) separated profiles emerged as the most effective for brokers, as adolescents in this profile generally experienced more positive and less negative brokering attitudes, regardless of their brokering frequency. Parent-adolescent acculturation profiles may be a useful construct in capturing the interplay of cultural and relational settings and their effects on multifaceted language brokering experiences.

16.
Ambio ; 49(1): 197-207, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31020611

RESUMO

Risks of pathogenic bacteria to the health of both human beings and water ecosystems have been widely acknowledged. However, traditional risk assessment methods based on fecal indicator bacteria and/or pure culture are not comprehensive at the community level, mainly owing to the limited taxonomic coverage. Here, we combined the technique of high-throughput sequencing and the concept of metacommunity to assess the potential pathogenic bacterial communities in an economically and ecologically crucial but highly polluted river-the North Canal River (NCR) in Haihe River Basin located in North China. NCR presented a significant environmental gradient, with the highest, moderate, and lowest levels of pollution in the up-, middle, and downstream. After multiple analyses, we successfully identified 48 genera, covering nine categories of potential pathogens (mainly human pathogens). The most abundant genus was Acinetobacter, which was rarely identified as a pathogen bacterium in previous studies of NCR. At the community level, we observed significant geographical variation of community composition and structure. Such a high level of geographical variation was mainly derived from differed abundance of species among sections along the river, especially the top seven Operational Taxonomic Units (OTUs). For example, relative abundance of OTU1 (Gammaproteobacteria/Acinetobacter) increased significantly from upstream towards downstream. Regarding the underlying mechanisms driving community geographical variation, environmental filtering was identified as the dominant ecological process and total nitrogen as the most influential environmental variable. Altogether, this study provided a comprehensive profile of potential pathogenic bacteria in NCR and revealed the underlying mechanisms of community succession. Owing to their high abundance and wide geographical distribution, we suggest that potential pathogens identified in this study should be incorporated into future monitoring and management programs in NCR. By revealing the correlation between environmental factors and community composition, the results obtained in this study have significant implications for early warning and risk assessment of potential pathogen bacteria, as well as management practices in highly polluted river ecosystems.


Assuntos
Ecossistema , Rios , Bactérias , China , Monitoramento Ambiental , Humanos , Nitrogênio
17.
Can J Cardiol ; 35(11): 1523-1533, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31679622

RESUMO

BACKGROUND: The diagnostic performance of coronary computed tomography angiography-derived fractional flow reserve (CT-FFR) in detecting ischemia in myocardial bridging (MB) has not been investigated to date. METHODS: This retrospective multicentre study included 104 patients with left anterior descending MBs. MB was classified as either superficial or deep, short, or long, whereas all MB vessels were further divided into <50%, 50% to 69%, and ≥70% groups, according to proximal lumen stenosis on invasive coronary angiography. Diagnostic performance and receiver operating characteristics (ROC) of CT-FFR to detect lesion-specific ischemia was assessed on a per-vessel level, using invasive FFR as reference standard. Intraclass correlation coefficient (ICC) and Bland-Altman plots were used for agreement measurement. RESULTS: Forty-eight MB vessels (46.2%) showed ischemia by invasive FFR (≤0.80). Sensitivity, specificity, and accuracy of CT-FFR to detect functional ischemia were 0.96 (0.85 to 0.99), 0.84 (0.71 to 0.92), and 0.89 (0.81 to 0.94), respectively, in all MB vessels. There were no differences in diagnostic performance between superficial and deep MB or between short and long MB (all P > 0.05). The accuracy of CT-FFR was 0.96 (0.85 to 0.99) in ≥70% stenosis, 0.82 (0.67 to 0.91) in 50% to 69% stenosis, and 0.89 (0.51 to 0.99) in <50% stenosis (P = 0.081). Bland-Altman analysis showed a slight mean difference between CT-FFR and invasive FFR of 0.014 (95% limit of agreement, -0.117 to 0.145). The ICC was 0.775 (95% confidence interval, 0.685-0.842, P < 0.001). CONCLUSIONS: CT-FFR demonstrated high diagnostic performance for identifying functional ischemia in vessels with MB and concomitant proximal atherosclerotic disease when compared with invasive FFR. However, the clinical use of CT-FFR in patients with MB needs further study for stronger and more robust results.

18.
ACS Appl Mater Interfaces ; 11(50): 46800-46807, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31738044

RESUMO

In next generation lithium-ion batteries (LIBs), silicon is a promising electrode material due to its surprisingly high specific capacity, but it suffers from serious volume changes during the lithiation/delithiation process which gradually lead to the destruction of the electrode structure. A novel fluorinated copolymer with three different polar groups was synthesized to overcome this problem: carboxylic acid, amide, and fluorinated groups on a single polymer backbone. Moreover, a dual cross-linked network binder was prepared by thermal polymerization of the fluorinated copolymer and sodium alginate. Unlike the common chemical cross-linked network with a gradual and nonreversible fracturing, the dual cross-linked network which combines chemical and physical cross-linking could effectively hold the silicon particles during the volume change process. As a result, excellent electrochemical performance (1557 mAh g-1 at a 4 A g-1 current density after 200 cycles) was achieved with this novel reversible cross-linked binder. Further research studies with regard to the influences of fluorine and acrylamide content were conducted to systematically evaluate the designed binder. Moreover, with the help of new binder, the silicon/graphite and silicon oxide/graphite electrode exhibit superb cycle performance with capacity fade rate of 0.1% and 0.025% per cycle over 200 and 700 cycles, respectively. This novel and unsophisticated design gives a result for fabrication of high-performance Si based electrodes and advancement of the realization of practical application.

19.
Nanoscale ; 11(46): 22261-22269, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31746907

RESUMO

Low-cost and highly effective transition metal oxides are being widely researched as one of the most promising electrocatalysts for the oxygen evolution reaction (OER). However, traditional transition metal oxides suffer from sluggish reaction kinetics due to their intrinsically poor electronic conductivity. Herein, we demonstrate a facile polydopamine-assisted carburization strategy for the confined synthesis of novel NiOx/Ni ultrathin heterostructured nanosheets. Benefiting from the large exposed surface area and fast charge transfer, the obtained ultrathin NiOx/Ni heterostructured nanosheets exhibit an overpotential of 358 mV at a current density of 10 mA cm-2 and a small Tafel slope of 51 mV dec-1, outperforming other reported representative nickel oxide based materials and commercial Ir/C catalysts. In addition, a sustainable and efficient overall water-splitting electrolyzer integrated ultrathin NiOx/Ni nanosheets with commercial Pt/C can be effectively and stably driven by solar cells.

20.
Nanoscale ; 11(38): 17571-17578, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31553015

RESUMO

Exploring highly active and durable Earth-abundant electrocatalysts to replace the precious noble metals holds great promise for the hydrogen evolution reaction (HER) from water splitting. Herein, a novel (110) high-index faceted binary-metal selenide (FeNiSe) nanosheet array grown on electrochemically exfoliated graphene foil (FeNiSe-NS/EG) is developed from its vertically-oriented NiFe-LDH nanosheet/EG precursor through a low-temperature selenization reaction. Benefiting from its unique 3D configuration and enhanced electrical conductivity, the obtained FeNiSe-NS/EG electrode exhibits excellent electrocatalytic activity toward the HER with small overpotentials of -187 and -222 mV at current densities of 10 and 20 mA cm-2, a low Tafel slope of 65 mV dec-1, and remarkable long term stability in alkaline media, outperforming the recently reported NiFe-based non-precious metal HER catalysts. Theoretical calculations and experimental results reveal that the synergistic effects of the exposed (110) high-index facets and Fe dopants give rise to a greatly enhanced HER performance.

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