Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Nanotechnology ; 28(7): 075101, 2017 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-28081003

RESUMO

The determination of specific nucleic acid sequences is key in identifying disease-causing pathogens and genetic diseases. In this paper we report the utilization of Fe-nitrilotriacetic acid coordination polymer nanowires as an effective nanoquencher for fluorescence-enhanced nucleic acid detection. The detection is fast and the whole process can be completed within 15 min. This nanosensor shows a low detection limit of 0.2 nM with selectivity down to single-base mismatch. This work provides us with an attractive sensing platform for applications.


Assuntos
Técnicas Biossensoriais , Cloretos/química , Complexos de Coordenação/química , DNA de Cadeia Simples/análise , Compostos Férricos/química , Ácido Nitrilotriacético/química , Sondas de Oligonucleotídeos/química , Limite de Detecção , Nanofios/química , Nanofios/ultraestrutura , Polímeros , Soluções , Espectrometria de Fluorescência
2.
Angew Chem Int Ed Engl ; 54(50): 15226-30, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26494434

RESUMO

Two-dimensional (2D) lateral heterostructures have emerged as a hot topic in the fast evolving field of advanced functional materials , but their fabrication is challenging. The layer-structured WS2 was theoretically demonstrated to be inert to oxidation except for the monolayer, which can be selectively oxidized owing to the simultaneous interaction of oxygen with both sides. Combined with the theoretical calculations, a new method was developed for the successful construction of 2D lateral heterostructures of WS2 /WO3 ⋅H2 O in an ambient environment, based on a simple liquid-phase solution exfoliation. These lateral heterostructures of WS2 /WO3 ⋅H2 O have interesting properties, as indicated by enhanced photocatalytic activity toward the degradation of methyl orange (MO).

3.
Public Health Rev ; 45: 1605579, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487619

RESUMO

Objectives: Women's health status is better than men but the opposite is true for female smokers who usually have poorer long-health outcomes than male smokers. The objectives of this study were to thoroughly reviewed and analyzed relevant literature and to propose a hypothesis that may explain this paradox phenomenon. Methods: We conducted a search of literature from three English databases (EMBASE, MEDLINE, and Google Scholar) from inception to 13 November 2023. A combination of key words and/or subject headings in English was applied, including relevant terms for cigarette smoking, sex/gender, pregnancy, and health indicators. We then performed analysis of the searched literature. Results: Based on this review/analysis of literature, we proposed a hypothesis that may explain this paradox phenomenon: female smokers have worse long-term health outcomes than male smokers because some of them smoke during pregnancy, and the adverse effects of cigarette smoking during pregnancy is much stronger than cigarette smoking during non-pregnancy periods. Conclusion: Approval of our pregnancy-amplification theory could provide additional evidence on the adverse effect on women's long-term health outcomes for cigarette smoking during pregnancy.

4.
Front Genet ; 15: 1376721, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933922

RESUMO

Background: Circular RNAs (circRNAs) play an important role in the occurrence and development of diseases. However, the role of circRNAs in male smokers with chronic obstructive pulmonary disease (COPD) remains unclear. Methods: Stable COPD patients and healthy controls were recruited. Peripheral blood mononuclear cells (PBMCs) were extracted. After high-throughput RNA sequencing (RNA-Seq) of PBMCs, a bioinformatics method was used to analyse differentially expressed (DE) circRNAs (DEcircRNAs) and mRNAs (DEmRNAs). Results: Total of 114 DEcircRNAs and 58 DEmRNAs were identified. Functional enrichment analysis showed that processes related to COPD include the regulation of interleukin (IL)-18, IL-5 and the NLRP3 inflammasome; differentiation of T helper type 1 (Th1), Th2, and Th17 cells, and the AMPK, Wnt, JAK-STAT, and PI3K-Akt signalling pathways. In the protein-protein interaction (PPI) network, the core genes were MYO16, MYL4, SCN4A, NRCAM, HMCN1, MYOM2, and IQSEC3. Small-molecule prediction results revealed potential drugs for the COPD treatment. Additionally, the circRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) regulatory network was constructed. Conclusion: This study identified a set of dysregulated circRNAs and mRNAs and revealed potentially important genes, pathways, new small-molecule drugs and ceRNA regulatory networks in male smokers with COPD. These circRNAs might be prospective biomarkers or potential molecular targets of the ceRNA mechanism for COPD.

5.
BMJ Open ; 12(8): e055672, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35914904

RESUMO

OBJECTIVE: To accurately estimate the global prevalence of non-tuberculous mycobacteria (NTM) in adults with non-cystic fibrosis (non-CF) bronchiectasis and to determine the proportion of NTM species and subspecies in clinical patients from 2006 to 2021. DESIGN: Systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: Medline, Embase, Cochrane Library and Web of Science were searched for articles published between 2006 and 2021. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included all the prospective or retrospective studies without language restrictions and all patients were adults (≥18 years of age) with non-CF bronchiectasis. The studies estimated the effect size of the prevalence of NTM with a sample size ≥40, and patients were registered in and after 2006. DATA EXTRACTION AND SYNTHESIS: Two reviewers screened the titles, abstracts and full texts independently. Relevant information was extracted and curated into tables. Risk of bias was evaluated following the Cochrane Collaboration's tool. Meta-analysis was performed with software R Statistics V.3.6.3 using random effect model with 95% CI. I2 index and Q statistics were calculated to assess the heterogeneity, and mixed-effects meta-regression analyses were performed to identify the sources of heterogeneity. The proportions of NTM subspecies were examined using Shapiro-Wilk normality test in R. RESULTS: Of all the 2014 studies yielded, 24 met the inclusion criteria. Of these, 14 were identified to be randomised controlled studies and included for an accurate estimation. The global prevalence of NTM in adults with non-CF bronchiectasis from 2006 to 2021 was estimated to be approximately 10%, with great variations primarily due to geographical location. Mycobacterium avium complex was the most common subspecies, followed by Mycobacterium simiae and Mycobacterium gordonae. CONCLUSIONS: The prevalence of NTM in adults with non-CF bronchiectasis has been on the rise and the most common subspecies changed greatly in recent years. More cohort studies should be done in many countries and regions for future estimates. PROSPERO REGISTRATION NUMBER: CRD42020168473.


Assuntos
Bronquiectasia , Micobactérias não Tuberculosas , Adulto , Bronquiectasia/epidemiologia , Bronquiectasia/microbiologia , Fibrose , Humanos , Prevalência , Estudos Prospectivos , Estudos Retrospectivos
6.
RSC Adv ; 10(64): 38989-38999, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-35518414

RESUMO

The traditional strategy for fabricating transition metal/carbon composite microwave absorbing materials (MAMs) is to combine different metallic salts and carbon precursors via various techniques, in which raw material waste and environmental pollution are inevitable. In this work, without addition of any metallic salts, natural iron embedded hierarchically porous carbon (HPC) composites are synthesized for the first time via facile pyrolysis and subsequent "reductive activation" with KOH. Using KOH to react with carbon to generate H2 can not only generate abundant nanoscale structures in the composites, but also in situ reduce the natural iron present in the bio-precursor to Fe nanoparticles, which facilitates the interfacial polarization and conductive loss of samples considerably. In turn, the modulation of graphitization degree could be realized by simply adjusting the ingredient ratio. Due to the synergistic effect between porosity and graphitization degree, the impedance matching of composites can be well regulated. The reflection loss of HPC-1 achieves -53.6 dB and the effective absorption bandwidth can cover the whole X and Ku bands with a thickness of only 1.4-2.4 mm. This study may pave a way to research on using bio-precursors rich in iron to synthesize high-efficiency and thin-thickness microwave absorbers and promote the diversified development of bio-derived materials in a gentle and facile way.

7.
ACS Nano ; 9(3): 3369-76, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25716070

RESUMO

To well address the problems of large volume change and dissolution of Fe3O4 nanomaterials during Li(+) intercalation/extraction, herein we demonstrate a one-step in situ nanospace-confined pyrolysis strategy for robust yolk-shell nanospindles with very sufficient internal void space (VSIVS) for high-rate and long-term lithium ion batteries (LIBs), in which an Fe3O4@Fe3C core@shell nanoparticle is well confined in the compartment of a hollow carbon nanospindle. This particular structure can not only introduce VSIVS to accommodate volume change of Fe3O4 but also afford a dual shell of Fe3C and carbon to restrict Fe3O4 dissolution, thus providing dual roles for greatly improving the capacity retention. As a consequence, Fe3O4@Fe3C-C yolk-shell nanospindles deliver a high reversible capacity of 1128.3 mAh g(-1) at even 500 mA g(-1), excellent high rate capacity (604.8 mAh g(-1) at 2000 mA g(-1)), and prolonged cycling life (maintaining 1120.2 mAh g(-1) at 500 mA g(-1) for 100 cycles) for LIBs, which are much better than those of Fe3O4@C core@shell nanospindles and Fe3O4 nanoparticles. The present Fe3O4@Fe3C-C yolk-shell nanospindles are the most efficient Fe3O4-based anode materials ever reported for LIBs.

8.
Nanoscale ; 4(2): 613-20, 2012 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-22159272

RESUMO

Owing to their extensive practical applications and fundamental importance, the controllable synthesis of well-faceted anatase TiO(2) crystal with high percentage of reactive facets has attracted increasing attention. Here, nano-sized anatase TiO(2) sheets mainly dominated by {001} facets had been prepared on graphene sheets by using a facile solvothermal synthetic route. The percentage of {001} facets in TiO(2) nanosheets was calculated to be ca. 64%. The morphologies, structural properties, growth procedures and photocatalytic activities of the resultant TiO(2)/graphene nanocomposites were investigated. In comparison with commercial P25 and pure TiO(2) nanosheets, the composite exhibited significant improvement in photocatalytic degradation of the azo dye Rhodamine B under visible light irradiation. The enhancement of photocatalytic activity and stability was attributed to the effective charge anti-recombination of graphene and the high catalytic activity of {001} facets.


Assuntos
Grafite/química , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Rodaminas/química , Rodaminas/efeitos da radiação , Titânio/química , Titânio/efeitos da radiação , Catálise/efeitos da radiação , Grafite/efeitos da radiação , Luz , Teste de Materiais , Nanoestruturas/ultraestrutura , Tamanho da Partícula
9.
J Phys Chem B ; 115(45): 13175-80, 2011 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21967597

RESUMO

In order to investigate the structural and dynamical properties of ferroelectric liquid crystal (FLC) in different phases a model compound [4-(3)-(S)-methyl-2-(S)-chloropentanoyloxy)]-4'-nonyloxy-biphenyl (3M2CPNOB) is synthesized. High resolution transmission electron microscopy (HR-TEM) is applied to observe the morphology of 3M2CPNOB and temperature-dependent solid state (13)C NMR to record (13)C chemical shifts at different phases. A liquid nitrogen quenching method is used to maintain the conformation of the mesophases for HR-TEM experiments. TEM images show that all the smectic A (SmA), smectic C* (SmC*) and crystalline phases have lamellar morphology. The interplanar distances in the crystalline phase are smaller than those in SmA and SmC* phases because of denser arrangement of the molecules. Both (13)C chemical shifts and line shape vary with different phases. The experimental results suggest that SmC* phase as an intermediate occurs in the anisotropy transition process from SmA to crystalline phase, the helical structure of the SmC* phase unwinds in the magnetic field and the conformations of the SmA and isotropic phase are very similar.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA