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1.
Nature ; 605(7910): 470-476, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35585339

RESUMO

Conventional thermochemical syntheses by continuous heating under near-equilibrium conditions face critical challenges in improving the synthesis rate, selectivity, catalyst stability and energy efficiency, owing to the lack of temporal control over the reaction temperature and time, and thus the reaction pathways1-3. As an alternative, we present a non-equilibrium, continuous synthesis technique that uses pulsed heating and quenching (for example, 0.02 s on, 1.08 s off) using a programmable electric current to rapidly switch the reaction between high (for example, up to 2,400 K) and low temperatures. The rapid quenching ensures high selectivity and good catalyst stability, as well as lowers the average temperature to reduce the energy cost. Using CH4 pyrolysis as a model reaction, our programmable heating and quenching technique leads to high selectivity to value-added C2 products (>75% versus <35% by the conventional non-catalytic method and versus <60% by most conventional methods using optimized catalysts). Our technique can be extended to a range of thermochemical reactions, such as NH3 synthesis, for which we achieve a stable and high synthesis rate of about 6,000 µmol gFe-1 h-1 at ambient pressure for >100 h using a non-optimized catalyst. This study establishes a new model towards highly efficient non-equilibrium thermochemical synthesis.

2.
Mol Cell Proteomics ; 22(9): 100623, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37481071

RESUMO

Data-independent acquisition (DIA) mass spectrometry-based proteomics generates reproducible proteome data. The complex processing of the DIA data has led to the development of multiple data analysis tools. In this study, we assessed the performance of five tools (OpenSWATH, EncyclopeDIA, Skyline, DIA-NN, and Spectronaut) using six DIA datasets obtained from TripleTOF, Orbitrap, and TimsTOF Pro instruments. By comparing identification and quantification metrics and examining shared and unique cross-tool identifications, we evaluated both library-based and library-free approaches. Our findings indicate that library-free approaches outperformed library-based methods when the spectral library had limited comprehensiveness. However, our results also suggest that constructing a comprehensive library still offers benefits for most DIA analyses. This study provides comprehensive guidance for DIA data analysis tools, benefiting both experienced and novice users of DIA-mass spectrometry technology.


Assuntos
Proteoma , Proteômica , Espectrometria de Massas/métodos , Proteômica/métodos , Proteoma/análise , Biblioteca Gênica , Análise de Dados
3.
Environ Res ; 237(Pt 1): 116915, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37598841

RESUMO

Water fluoridation is considered a safe and effective public health strategy to improve oral health. This review aimed to systematically summarize the available evidence of water fluoridation in Australia, focusing on the history, health impacts, cost effectiveness, challenges, and limitations. A systematic search was conducted on the Ovid Medline, Web of Science, Scopus, ProQuest Central, Cinahl, and Informit databases to identify literature on water fluoridation in Australia. A grey literature search and backward snowballing were used to capture additional literature. Primary studies, reviews, letters, and opinion papers were included in the quantitative analysis and summarized based on the year of publication and geographical location. The data were extracted from primary studies and summarized under three subheadings: history, community health impacts and the limitations and challenges. Water fluoridation in Australia was first implemented in 1953 in Tasmania. Most states and territories in Australia embraced water fluoridation by 1977 and currently, 89% of the Australian population has access to fluoridated drinking water. Studies report that water fluoridation has reduced dental caries by 26-44% in children, teenagers, and adults, benefiting everyone regardless of age, income, or access to dental care. It has been recognized as a cost-effective intervention to prevent dental caries, especially in rural and low-income areas. Water fluoridation as a public health measure has faced challenges, including political and public opposition, implementation and maintenance costs, access and equity, communication and education, and ethical concerns. Variations in research activities on water fluoridation across Australian states and territories over the last seven decades can be due to several factors, including the time of implementation, funding, and support. Ongoing monitoring and research to review and update optimal fluoride levels in drinking water in Australia is warranted to ensure sustainable benefits on oral health while preventing any adverse impacts.

4.
Proc Natl Acad Sci U S A ; 117(12): 6316-6322, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32156723

RESUMO

Multimetallic nanoclusters (MMNCs) offer unique and tailorable surface chemistries that hold great potential for numerous catalytic applications. The efficient exploration of this vast chemical space necessitates an accelerated discovery pipeline that supersedes traditional "trial-and-error" experimentation while guaranteeing uniform microstructures despite compositional complexity. Herein, we report the high-throughput synthesis of an extensive series of ultrafine and homogeneous alloy MMNCs, achieved by 1) a flexible compositional design by formulation in the precursor solution phase and 2) the ultrafast synthesis of alloy MMNCs using thermal shock heating (i.e., ∼1,650 K, ∼500 ms). This approach is remarkably facile and easily accessible compared to conventional vapor-phase deposition, and the particle size and structural uniformity enable comparative studies across compositionally different MMNCs. Rapid electrochemical screening is demonstrated by using a scanning droplet cell, enabling us to discover two promising electrocatalysts, which we subsequently validated using a rotating disk setup. This demonstrated high-throughput material discovery pipeline presents a paradigm for facile and accelerated exploration of MMNCs for a broad range of applications.

5.
BMC Med Educ ; 23(1): 33, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650469

RESUMO

BACKGROUND: The concept of employability can help educators understand the variability in the career outcome of graduates. Within the health professional education (HPE) literature, various conceptions of employability are used and implied. This review considers how the concept 'employability' is depicted and characterised in HPE literature. METHODS: A scoping review was conducted. The authors searched Medline, Web of Science and Scopus databases for English language literature relevant to employability in HPE. Arksey and O'Malley's review protocol and the criteria defined in the preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews Checklist (PRISMA-ScR) were used with methodological guidance provided by Levac et al. and Peters et al. with the exception of formal stakeholder consultation. RESULTS: The search resulted in 158 articles, of which 34 articles were included in this review. Charting the included articles revealed that within the set of articles, there is much diversity in study design, geographical setting and health profession. Three conceptions of employability were identified: acquiring a professional job, sustaining employment and thriving in the workforce. CONCLUSION: Conceptions of employability in HPE are largely focused on listing skills and capabilities for entry into employment and sustaining a career. To address gaps in research, structural contributions to employability and institutional strategies to promote conditions for thriving in disruption should be explored.


Assuntos
Educação Profissionalizante , Emprego , Humanos
6.
Nano Lett ; 22(10): 3931-3938, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35503740

RESUMO

Conventional plastic foams are usually produced by fossil-fuel-derived polymers, which are difficult to degrade in nature. As an alternative, cellulose is a promising biodegradable polymer that can be used to fabricate greener foams, yet such a process typically relies on methods (e.g., freeze-drying and supercritical-drying) that are hardly scalable and time-consuming. Here, we develop a fast and scalable approach to prepare cellulose-graphite foams via rapidly cross-linking the cellulose fibrils in metal ions-containing solution followed by ambient drying. The prepared foams exhibit low density, high compressive strength, and excellent water stability. Moreover, the cross-linking of the cellulose fibrils can be triggered by various metal ions, indicating good universality. We further use density functional theory to reveal the cross-linking effect of different ions, which shows good agreement with our experimental observation. Our approach presents a sustainable route toward low-cost, environmentally friendly, and scalable foam production for a range of applications.


Assuntos
Celulose , Grafite , Íons , Polímeros , Água
7.
J Proteome Res ; 21(12): 3007-3015, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36315902

RESUMO

Isobaric labeling-based proteomics is widely applied in deep proteome quantification. Among the platforms for isobaric labeled proteomic data analysis, the commercial software Proteome Discoverer (PD) is widely used, incorporating the search engine CHIMERYS, while FragPipe (FP) is relatively new, free for noncommercial purposes, and integrates the engine MSFragger. Here, we compared PD and FP over three public proteomic data sets labeled using 6plex, 10plex, and 16plex tandem mass tags. Our results showed the protein abundances generated by the two software are highly correlated. PD quantified more proteins (10.02%, 15.44%, 8.19%) than FP with comparable NA ratios (0.00% vs. 0.00%, 0.85% vs. 0.38%, and 11.74% vs. 10.52%) in the three data sets. Using the 16plex data set, PD and FP outputs showed high consistency in quantifying technical replicates, batch effects, and functional enrichment in differentially expressed proteins. However, FP saved 93.93%, 96.65%, and 96.41% of processing time compared to PD for analyzing the three data sets, respectively. In conclusion, while PD is a well-maintained commercial software integrating various additional functions and can quantify more proteins, FP is freely available and achieves similar output with a shorter computational time. Our results will guide users in choosing the most suitable quantification software for their needs.


Assuntos
Proteoma , Proteômica , Proteoma/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Software
8.
Small ; 18(11): e2104761, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35049145

RESUMO

High-entropy nanoparticles have received notable attention due to their tunable properties and broad material space. However, these nanoparticles are not suitable for certain applications (e.g., battery electrodes), where their microparticle (submicron to micron) counterparts are more preferred. Conventional methods used for synthesizing high-entropy nanoparticles often involve various ultrafast shock processes. To increase the size thereby achieving high-entropy microparticles, longer reaction time (e.g., heating duration) is usually used, which may also lead to undesired particle overgrowth or even densified microstructures. In this work, an approach based on Joule heating for synthesizing high-entropy oxide (HEO) microparticles with uniform elemental distribution is reported. In particular, two key synthesis conditions are identified to achieve high-quality HEO microparticles: 1) the precursors need to be loosely packed to avoid densification; 2) the heating time needs to be accurately controlled to tens of seconds instead of using milliseconds (thermal shock) that leads to nanoparticles or longer heating duration that forms bulk structures. The utility of the synthesized HEO microparticles for a range of applications, including high-performance Li-ion battery anode and water oxidation catalyst. This study opens up a new door toward synthesizing high-entropy microparticles with high quality and broad material space.

9.
Clin Proteomics ; 19(1): 31, 2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-35953823

RESUMO

BACKGROUND: Classification of disease severity is crucial for the management of COVID-19. Several studies have shown that individual proteins can be used to classify the severity of COVID-19. Here, we aimed to investigate whether integrating four types of protein context data, namely, protein complexes, stoichiometric ratios, pathways and network degrees will improve the severity classification of COVID-19. METHODS: We performed machine learning based on three previously published datasets. The first was a SWATH (sequential window acquisition of all theoretical fragment ion spectra) MS (mass spectrometry) based proteomic dataset. The second was a TMTpro 16plex labeled shotgun proteomics dataset. The third was a SWATH dataset of an independent patient cohort. RESULTS: Besides twelve proteins, machine learning also prioritized two complexes, one stoichiometric ratio, five pathways, and five network degrees, resulting a 25-feature panel. As a result, a model based on the 25 features led to effective classification of severe cases with an AUC of 0.965, outperforming the models with proteins only. Complement component C9, transthyretin (TTR) and TTR-RBP (transthyretin-retinol binding protein) complex, the stoichiometric ratio of SAA2 (serum amyloid A proteins 2)/YLPM1 (YLP Motif Containing 1), and the network degree of SIRT7 (Sirtuin 7) and A2M (alpha-2-macroglobulin) were highlighted as potential markers by this classifier. This classifier was further validated with a TMT-based proteomic data set from the same cohort (test dataset 1) and an independent SWATH-based proteomic data set from Germany (test dataset 2), reaching an AUC of 0.900 and 0.908, respectively. Machine learning models integrating protein context information achieved higher AUCs than models with only one feature type. CONCLUSION: Our results show that the integration of protein context including protein complexes, stoichiometric ratios, pathways, network degrees, and proteins improves phenotype prediction.

10.
BMC Oral Health ; 22(1): 424, 2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-36138429

RESUMO

BACKGROUND: The COVID-19 pandemic challenged all healthcare providers including dental practitioners. This cross-sectional study aimed to investigate the dental practitioners' perceptions and attitudes towards the impacts of COVID-19 on their professional practice, career decision and patient care. METHODS: Data was collected from dental practitioners registered in New South Wales (NSW), Australia using an online survey. RESULTS AND CONCLUSION: Responses received from 206 dental practitioners revealed their perceptions and attitudes towards COVID-19 infection risk, clinical guidelines, and measures adopted to deliver patient care. Majority of participants perceived the risk of infection in dentistry was higher compared with other health professionals. Most dental practices have followed guidelines received from professional associations and adopted multiple measures such as providing hand sanitizer, social distancing, and risk screen, to ensure safe delivery of oral health care. Over 80% of dental practitioners raised concerns on patients' accessibility to dental care during the pandemic. Despite tele-dentistry was introduced, almost half of the participants did not recognize tele-dentistry as an effective alternative. Moreover, negative impacts of COVID-19 pandemic on dental practitioner's professional career have been reported, including lower practice safety, reduction in working hours and income. Noteworthy, one quarter of participants even considered changing their practice environment, moving sectors or even leaving their career in dentistry. However, majority of the dental practitioners are willing to stay in their current practice environment and continue their career in dentistry. Our observations demonstrate the systematic disruption to dental practice faced in Australia due to the COVID-19 pandemic. Providing dental practitioners with timely educational training and support is important to minimise negative impacts of the challenges and to optimise dental care.


Assuntos
COVID-19 , Higienizadores de Mão , Estudos Transversais , Odontologia , Odontólogos , Humanos , Pandemias , Papel Profissional , Inquéritos e Questionários
11.
J Evid Based Dent Pract ; 22(1): 101689, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35219467

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Sukriti KC. Wang XZ, Gallagher JE. Diagnostic sensitivity and specificity of host-derived salivary biomarkers in periodontal disease amongst adults: Systematic review. J Clin Periodontol 2020;47(3):289-308. doi:10.1111/jcpe.13218. SOURCE OF FUNDING: Information not available. TYPE OF STUDY/DESIGN: Systematic review.


Assuntos
Doenças Periodontais , Adulto , Biomarcadores , Humanos , Doenças Periodontais/diagnóstico , Sensibilidade e Especificidade
12.
J Evid Based Dent Pract ; 22(4): 101772, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36494110

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Mohammad-Rahimi H, Reza Motamedian S, Hossein Rohban M, Krois J, Uribe SE, Mahmoudinia E, Rokhshad R, Nadimi M, Schwendicke F, Deep learning for caries detection: A systematic review, J Dent, 2022,122, 104115. ISSN 0300-5712 https://doi.org/10.1016/j.jdent.2022.104115. SOURCE OF FUNDING: Information not available TYPE OF STUDY/DESIGN: Systematic review.


Assuntos
Aprendizado Profundo , Cárie Dentária , Humanos , Cárie Dentária/diagnóstico , Assistência Odontológica , Algoritmos
13.
J Evid Based Dent Pract ; 22(3): 101757, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36162886

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Rodrigues RP, Vidigal MT, Vieira WA, Nascimento GG, Sabino-Silva R, Blumenberg C, Siqueira MF, Siqueira WL, Paranhos LR. Salivary changes in chronic kidney disease and in patients undergoing hemodialysis: a systematic review and meta-analysis. Journal of Nephrology. 2022 Mar 2:1-29. SOURCE OF FUNDING: The work has been partially funded by CAPES-Finance Code 001. The authors have also acknowledged The Brazilian National Council for Scientific and Technological Development (CNPq) and Minas Gerais State Agency for Research and Development, Brazil (FAPEMIG) for the support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.


Assuntos
Falência Renal Crônica , Diálise Renal , Saliva , Salivação , Brasil , Humanos , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Saliva/química , Saliva/metabolismo , Salivação/fisiologia , Taxa Secretória
14.
Environ Res ; 196: 110455, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33212131

RESUMO

This study investigated the treatment of 100-mg/L Norfloxacin (NOR) wastewater containing high concentrations of sulfate through a combination of electrolysis, sulfate-reducing up-flow sludge bed (SRUSB), and biological contact oxidation reactor (BCOR) treatments. Results revealed that after 62 h, the reaction system had processed over 97% of the NOR. Additionally, electrolysis with sodium sulfate as the electrolyte transformed 87.8% of the NOR but only 33.5% of the total organic carbon (TOC). In the SRUSB, the TOC and SO42- contents were simultaneously reduced by 87.4% and 95.6%, respectively, providing a stable environment to the BCOR. In the BCOR, 36.3% and 85.9% of the NOR and TOC were degraded. High-performance liquid chromatography-tandem mass spectrometry analysis identified three possible degradation pathways under the attack of -OH during electrolysis, including defluorination, piperazinyl ring transformation, and quinolone ring transformation. Furthermore, the Illumina HiSeq sequencing results demonstrated that the sulfate-reducing bacteria (represented by Desulfobacter and Desulfobulbus) in the SRUSB and the sulfate-oxidizing bacteria (mainly consisting of Gammaproteobacteria and Alphaproteobacteria) in the BCOR played important roles in carbon chain oxidation and benzene ring opening and thoroughly degraded the electrolysis products. Thus, this method effectively overcomes the incomplete degradation and low removal efficiency issues associated with single electrolysis or biological methods in traditional processes.


Assuntos
Esgotos , Águas Residuárias , Reatores Biológicos , Eletrólise , Norfloxacino , Oxirredução , Sulfatos , Eliminação de Resíduos Líquidos
15.
Med Teach ; 43(6): 663-668, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33626292

RESUMO

The time and effort students devote to learning tasks has been related to student success and outcomes, however, the way students understand and experience time during their health professional education remains poorly understood. This article aims to address this gap in knowledge through a qualitative analysis of health professional students' engagement with a longitudinal portfolio assessment spanning two years. Thematic analysis of 7 focus groups conducted with oral health therapy students was performed. Four temporal dimensions of student engagement associated with the longitudinal portfolio assessment were identified: the organising effect of the assessment structure and timeline; flows of learning over time; individual perceptions of time; and having a future orientation. A fifth theme identified that circumstances or events can make or break the temporal rhythms of any of the dimensions. Our findings show that students' experiences of learning are affected by institutional arrangements as well as personal perceptions of time. Taking the experience of time beyond the concept of 'time management', we show how curricula contain under-recognised tools for students to authentically experience the complexities and contradictions of time in preparation for the context of health practice.


Assuntos
Saúde Bucal , Estudantes , Currículo , Grupos Focais , Humanos , Aprendizagem
16.
Small ; 16(31): e1907212, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597027

RESUMO

3D printing of lignocellulosic biomass (cellulose, hemicellulose, and lignin) has attracted increasing attention by using this abundant, sustainable, and ecofriendly material. While cellulose can be easily tailored into a highly viscous ink for 3D printing, after solvent evaporation, the final printed structures become highly porous, fragile, and easily fall apart in water due to its hydrophilic nature. Lignin, another crucial component of natural lignocellulose, has not yet been reported for ink printing due to its unfavorable rheological behavior. Herein, a low-cost direct ink printing strategy is developed to fabricate lignin-based 3D structures with lignin no further refined and a more compact microstructure as well as different functionalities compared with printed cellulose. By using a soft triblock copolymer as the crosslinking agent, the rheology of lignin-based inks can be adjusted from soft to rigid, and even enables vertical printing which requires stiff and self-supporting features. The lignin-based inks contain less water (≈40 wt%) and exhibit a much denser, stiffer structure, resulting in a wet tensile strength of ≈30 MPa, compared to only ≈0.6 MPa for printed cellulose. In addition, the unique macromolecular structure of lignin also demonstrates significantly improved stability in water and under heat, as well as UV-blocking performance.


Assuntos
Tinta , Lignina , Celulose , Hidrogéis , Impressão Tridimensional
17.
BMC Oral Health ; 20(1): 169, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532263

RESUMO

BACKGROUND: Recent preventive strategies for dental caries focus on targeting the mechanisms underlying biofilm formation, including the inhibition of bacterial adhesion. A promising approach to prevent bacterial adhesion is to modify the composition of acquired salivary pellicle. This in vitro study investigated the effect and possible underlying mechanism of pellicle modification by casein phosphopeptide (CPP) on Streptococcus mutans (S. mutans) initial adhesion, and the impact of fluoride on the efficacy of CPP. METHODS: The salivary pellicle-coated hydroxyapatite (s-HA) discs were treated with phosphate buffered saline (negative control), heat-inactivated 2.5% CPP (heat-inactivated CPP), 2.5% CPP (CPP) or 2.5% CPP supplemented with 900 ppm fluoride (CPP + F). After cultivation of S. mutans for 30 min and 2 h, the adherent bacteria were visualized by scanning electron microscopy (SEM) and quantitatively evaluated using the plate count method. Confocal laser scanning microscopy (CLSM) was used to evaluate the proportions of total and dead S. mutans. The concentrations of total, free, and bound calcium and fluoride in the CPP and fluoride-doped CPP solutions were determined. The water contact angle and zeta potential of s-HA with and without modification were measured. The data were statistically analyzed using one-way ANOVA followed by a Turkey post hoc multiple comparison test. RESULTS: Compared to the negative control group, the amount of adherent S. mutans significantly reduced in the CPP and CPP + F groups, and was lowest in the CPP + F group. CLSM analysis showed that there was no statistically significant difference in the proportion of dead S. mutans between the four groups. Water contact angle and zeta potential of s-HA surface significantly decreased in the CPP and CPP + F groups as compared to the negative control group, and both were lowest in the CPP + F group. CONCLUSIONS: Pellicle modification by CPP inhibited S. mutans initial adhesion to s-HA, possibly by reducing hydrophobicity and negative charge of the s-HA surface, and incorporating fluoride into CPP further enhanced the anti-adhesion effect.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Caseínas/farmacologia , Cárie Dentária/prevenção & controle , Durapatita/química , Fluoretos/farmacologia , Fosfopeptídeos/farmacologia , Saliva/química , Streptococcus mutans/efeitos dos fármacos , Biofilmes , Materiais Revestidos Biocompatíveis/química , Suscetibilidade à Cárie Dentária , Humanos , Saliva/microbiologia , Proteínas e Peptídeos Salivares/metabolismo , Streptococcus mutans/isolamento & purificação , Streptococcus mutans/fisiologia , Turquia
18.
Small ; 15(47): e1904881, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31608596

RESUMO

Carbon-black-supported nanoparticles (CNPs) have attracted considerable attention for their intriguing catalytic properties and promising applications. The traditional liquid synthesis of CNPs commonly involves demanding operation conditions and complex pre- or post-treatments, which are time consuming and energy inefficient. Herein, a rapid, scalable, and universal strategy is reported to synthesize highly dispersed metal nanoparticles embedded in a carbon matrix via microwave irradiation of carbon black with preloaded precursors. By optimizing the amount of carbon black, the microwave absorption is dramatically improved while the thermal dissipation is effectively controlled, leading to a rapid temperature increase in carbon black, ramping to 1270 K in just 6 s. The whole synthesis process requires no capping agents or surfactants, nor tedious pre- or post-treatments of carbon black, showing tremendous potential for mass production. As a proof of concept, the synthesis of ultrafine Ru nanoparticles (≈2.57 nm) uniformly embedded in carbon black using this microwave heating technique is demonstrated, which displays remarkable electrocatalytic performance when used as the cathode in a Li-O2 battery. This microwave heating method can be extended to the synthesis of other nanoparticles, thereby providing a general methodology for the mass production of carbon-supported catalytic nanoparticles.

19.
Plant Biotechnol J ; 17(2): 397-409, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29992702

RESUMO

Morella rubra, red bayberry, is an economically important fruit tree in south China. Here, we assembled the first high-quality genome for both a female and a male individual of red bayberry. The genome size was 313-Mb, and 90% sequences were assembled into eight pseudo chromosome molecules, with 32 493 predicted genes. By whole-genome comparison between the female and male and association analysis with sequences of bulked and individual DNA samples from female and male, a 59-Kb region determining female was identified and located on distal end of pseudochromosome 8, which contains abundant transposable element and seven putative genes, four of them are related to sex floral development. This 59-Kb female-specific region was likely to be derived from duplication and rearrangement of paralogous genes and retained non-recombinant in the female-specific region. Sex-specific molecular markers developed from candidate genes co-segregated with sex in a genetically diverse female and male germplasm. We propose sex determination follow the ZW model of female heterogamety. The genome sequence of red bayberry provides a valuable resource for plant sex chromosome evolution and also provides important insights for molecular biology, genetics and modern breeding in Myricaceae family.


Assuntos
Evolução Molecular , Genoma de Planta/genética , Myrica/genética , Mapeamento Cromossômico , Flores/genética , Flores/crescimento & desenvolvimento , Flores/fisiologia , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/fisiologia , Marcadores Genéticos/genética , Anotação de Sequência Molecular , Myrica/crescimento & desenvolvimento , Myrica/fisiologia , Especificidade de Órgãos , Melhoramento Vegetal
20.
Chemistry ; 25(10): 2604-2609, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30537126

RESUMO

Si/SiOC composites are promising high-capacity anode materials for lithium-ion batteries since the SiOC matrix can effectively buffer the volumetric change of Si during cycling. However, a structure of Si nanoparticles (NPs) enwrapped by a continuous SiOC phase typically shows poor cyclic stability and low charge/discharge rate due to structure failure of bulk SiOC shells derived from carbon-rich organosilicon. To address this issue, in this work, an Si/SiOC nanocomposite with volume-change-buffering microstructure, in which Si NPs are uniformly dispersed in a matrix of SiOC nanospheres, has been synthesized. Our results show that the space between Si and SiOC NPs can accommodate the large volume change of Si during cycling and facilitate infiltration of the electrolyte. The nanostructured SiOC skeleton serves as both a mechanically robust buffer to alleviate the intrinsic expansion of Si and an effective electron conductor. The Si/SiOC NP composite displays significantly increased capacity and cyclic stability compared with pure SiOC, and delivers reversible capacities of around 800 mA h-1 g-1 at a current density of 100 mA g-1 (approximately 100 % capacity retention after 100 cycles) and around 600 mA h-1 g-1 at 500 mA g-1 (capacity retention about 80 % after 500 cycles).

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