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1.
J Virol ; 97(1): e0177822, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36598200

RESUMO

Globalization and climate change have contributed to the simultaneous increase and spread of arboviral diseases. Cocirculation of several arboviruses in the same geographic region provides an impetus to study the impacts of multiple concurrent infections within an individual vector mosquito. Here, we describe coinfection and superinfection with the Mayaro virus (Togaviridae, Alphavirus) and Zika virus (Flaviviridae, Flavivirus) in vertebrate and mosquito cells, as well as Aedes aegypti adult mosquitoes, to understand the interaction dynamics of these pathogens and effects on viral infection, dissemination, and transmission. Aedes aegypti mosquitoes were able to be infected with and transmit both pathogens simultaneously. However, whereas Mayaro virus was largely unaffected by coinfection, it had a negative impact on infection and dissemination rates for Zika virus compared to single infection scenarios. Superinfection of Mayaro virus atop a previous Zika virus infection resulted in increased Mayaro virus infection rates. At the cellular level, we found that mosquito and vertebrate cells were also capable of being simultaneously infected with both pathogens. Similar to our findings in vivo, Mayaro virus negatively affected Zika virus replication in vertebrate cells, displaying complete blocking under certain conditions. Viral interference did not occur in mosquito cells. IMPORTANCE Epidemiological and clinical studies indicate that multiple arboviruses are cocirculating in human populations, leading to some individuals carrying more than one arbovirus at the same time. In turn, mosquitoes can become infected with multiple pathogens simultaneously (coinfection) or sequentially (superinfection). Coinfection and superinfection can have synergistic, neutral, or antagonistic effects on viral infection dynamics and ultimately have impacts on human health. Here we investigate the interaction between Zika virus and Mayaro virus, two emerging mosquito-borne pathogens currently circulating together in Latin America and the Caribbean. We find a major mosquito vector of these viruses-Aedes aegypti-can carry and transmit both arboviruses at the same time. Our findings emphasize the importance of considering co- and superinfection dynamics during vector-pathogen interaction studies, surveillance programs, and risk assessment efforts in epidemic areas.


Assuntos
Aedes , Infecções por Alphavirus , Coinfecção , Superinfecção , Infecção por Zika virus , Animais , Humanos , Aedes/virologia , Alphavirus , Infecções por Alphavirus/complicações , Infecções por Alphavirus/virologia , Mosquitos Vetores/virologia , Vertebrados/virologia , Zika virus , Infecção por Zika virus/complicações , Infecção por Zika virus/virologia
2.
Nature ; 543(7647): 690-694, 2017 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-28297708

RESUMO

A zeolite with structure type MFI is an aluminosilicate or silicate material that has a three-dimensionally connected pore network, which enables molecular recognition in the size range 0.5-0.6 nm. These micropore dimensions are relevant for many valuable chemical intermediates, and therefore MFI-type zeolites are widely used in the chemical industry as selective catalysts or adsorbents. As with all zeolites, strategies to tailor them for specific applications include controlling their crystal size and shape. Nanometre-thick MFI crystals (nanosheets) have been introduced in pillared and self-pillared (intergrown) architectures, offering improved mass-transfer characteristics for certain adsorption and catalysis applications. Moreover, single (non-intergrown and non-layered) nanosheets have been used to prepare thin membranes that could be used to improve the energy efficiency of separation processes. However, until now, single MFI nanosheets have been prepared using a multi-step approach based on the exfoliation of layered MFI, followed by centrifugation to remove non-exfoliated particles. This top-down method is time-consuming, costly and low-yield and it produces fragmented nanosheets with submicrometre lateral dimensions. Alternatively, direct (bottom-up) synthesis could produce high-aspect-ratio zeolite nanosheets, with improved yield and at lower cost. Here we use a nanocrystal-seeded growth method triggered by a single rotational intergrowth to synthesize high-aspect-ratio MFI nanosheets with a thickness of 5 nanometres (2.5 unit cells). These high-aspect-ratio nanosheets allow the fabrication of thin and defect-free coatings that effectively cover porous substrates. These coatings can be intergrown to produce high-flux and ultra-selective MFI membranes that compare favourably with other MFI membranes prepared from existing MFI materials (such as exfoliated nanosheets or nanocrystals).

3.
Arch Insect Biochem Physiol ; 112(2): e21992, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36575628

RESUMO

The small brown planthopper, Laodelphax striatellus, is a destructive pest insect found in rice fields. L. striatellus not only directly feeds on the phloem sap of rice but also transmits various viruses, such as rice stripe virus (RSV) and rice black-streaked dwarf virus, resulting in serious loss of rice production. RSV is a rice-infecting virus that is found mainly in Korea, China, and Japan. To develop novel strategies to control L. striatellus and L. striatellus-transmitted viruses, various studies have been conducted, based on vector biology, interactions between vectors and pathogens, and omics, including transcriptomics, proteomics, and metabolomics. In this review, we discuss the roles of saliva proteins during phloem sap-sucking and virus transmission, the diversity and role of the microbial community in L. striatellus, the profile and molecular mechanisms of insecticide resistance, classification of L. striatellus-transmitted RSV, its host range and symptoms, its genome composition and roles of virus-derived proteins, its distribution, interactions with L. striatellus, and resistance and control, to suggest future directions for integrated pest management to control L. striatellus and L. striatellus-transmitted viruses.


Assuntos
Hemípteros , Oryza , Tenuivirus , Animais , Tenuivirus/genética , Insetos Vetores/genética , Hemípteros/genética , Insetos/genética , Perfilação da Expressão Gênica , Proteínas Virais/metabolismo
4.
PLoS Genet ; 16(5): e1008772, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32365064

RESUMO

In the postgenomics era, comparative genomics have advanced the understanding of evolutionary processes of neuropeptidergic signaling systems. The evolutionary origin of many neuropeptidergic signaling systems can be traced date back to early metazoan evolution based on the conserved sequences. Insect parathyroid hormone receptor (iPTHR) was previously described as an ortholog of vertebrate PTHR that has a well-known function in controlling bone remodeling. However, there was no sequence homologous to PTH sequence in insect genomes, leaving the iPTHR as an orphan receptor. Here, we identified the authentic ligand insect PTH (iPTH) for the iPTHR. The taxonomic distribution of iPTHR, which is lacking in Diptera and Lepidoptera, provided a lead for identifying the authentic ligand. We found that a previously described orphan ligand known as PXXXamide (where X is any amino acid) described in the cuttlefish Sepia officinalis has a similar taxonomic distribution pattern as iPTHR. Tests of this peptide, iPTH, in functional reporter assays confirmed the interaction of the ligand-receptor pair. Study of a model beetle, Tribolium castaneum, was used to investigate the function of the iPTH signaling system by RNA interference followed by RNA sequencing and phenotyping. The results suggested that the iPTH system is likely involved in the regulation of cuticle formation that culminates with a phenotype of defects in wing exoskeleton maturation at the time of adult eclosion. Moreover, RNAi of iPTHRs also led to significant reductions in egg numbers and hatching rates after parental RNAi.


Assuntos
Neuropeptídeos/metabolismo , Hormônio Paratireóideo/metabolismo , Receptores de Hormônios Paratireóideos/genética , Tribolium/anatomia & histologia , Animais , Evolução Molecular , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Fenótipo , Filogenia , Receptores de Hormônios Paratireóideos/metabolismo , Análise de Sequência de RNA , Tribolium/genética , Tribolium/metabolismo , Asas de Animais/anatomia & histologia
5.
J Med Internet Res ; 25: e43521, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36656626

RESUMO

BACKGROUND: An increasing number of medical journals are using social media to promote themselves and communicate with their readers. However, little is known about how medical journals use Twitter and what their social media management strategies are. OBJECTIVE: This study aimed to understand how medical journals use Twitter from a global standpoint. We conducted a broad, in-depth analysis of all the available Twitter accounts of medical journals indexed by major indexing services, with a particular focus on their social networks and content. METHODS: The Twitter profiles and metadata of medical journals were analyzed along with the social networks on their Twitter accounts. RESULTS: The results showed that overall, publishers used different strategies regarding Twitter adoption, Twitter use patterns, and their subsequent decisions. The following specific findings were noted: journals with Twitter accounts had a significantly higher number of publications and a greater impact than their counterparts; subscription journals had a slightly higher Twitter adoption rate (2%) than open access journals; journals with higher impact had more followers; and prestigious journals rarely followed other lesser-known journals on social media. In addition, an in-depth analysis of 2000 randomly selected tweets from 4 prestigious journals revealed that The Lancet had dedicated considerable effort to communicating with people about health information and fulfilling its social responsibility by organizing committees and activities to engage with a broad range of health-related issues; The New England Journal of Medicine and the Journal of the American Medical Association focused on promoting research articles and attempting to maximize the visibility of their research articles; and the British Medical Journal provided copious amounts of health information and discussed various health-related social problems to increase social awareness of the field of medicine. CONCLUSIONS: Our study used various perspectives to investigate how medical journals use Twitter and explored the Twitter management strategies of 4 of the most prestigious journals. Our study provides a detailed understanding of medical journals' use of Twitter from various perspectives and can help publishers, journals, and researchers to better use Twitter for their respective purposes.


Assuntos
Medicina , Mídias Sociais , Humanos , Fator de Impacto de Revistas , Metadados , Rede Social
6.
J Med Primatol ; 51(3): 195-198, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35266161

RESUMO

A pregnant common marmoset (Callithrix jacchus) showed tachypnea, hypothermia, and anorexia at close to the expected delivery date. Severe anemia and thrombocytopenia, schistocytes, and high levels of LDH and D-dimer were observed. Three days after the onset of clinical signs, a cesarean section was conducted due to stillbirth. Marmoset immediately recovered after surgery, and the abnormal CBC and blood chemistry parameters before surgery returned to the normal ranges. Diagnosis of pregnancy-associated thrombotic microangiopathy was made because removal of infant and placenta is curative. To the best of our knowledge, this is the first case report of thrombotic microangiopathy in a marmoset with preeclampsia.


Assuntos
Pré-Eclâmpsia , Microangiopatias Trombóticas , Animais , Callithrix , Callitrichinae , Cesárea/efeitos adversos , Cesárea/veterinária , Feminino , Pré-Eclâmpsia/diagnóstico , Gravidez , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/etiologia , Microangiopatias Trombóticas/terapia
7.
Macromol Rapid Commun ; 43(4): e2100648, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34935239

RESUMO

The application of nanofiber (NF) and porous metal-organic framework (MOF) has increasingly attracted attention for the protection of public health. This composite platform provides the physical sieving of particulate matters (PMs) and capturing gases, serving as an outstanding filtering medium with lightweight and multifunctionality. Herein, process design and optimization are performed to produce a multifunctional membrane comprised NFs and MOF particles. Electrospinning/electrospray techniques are used to fabricate a hybrid membrane of poly(vinyl alcohol) NF and Fe-BTC as an adsorptive MOF on a macroporous nonwoven (NW). Three types of filters are prepared by varying the order of processing steps, that is, MOF/NF/NW, MOF+NF/NW, and NF/MOF/NW, to elucidate the effect of the fabrication process in the filtration of air pollutant. The optimal filtration performance is achieved in MOF+NF/NW system: the highest filtration efficiency (97%) and outstanding gas capturing efficiencies (≈60% and ≈35% decreases from initial NH3 and H2 S concentrations, respectively). However, when air permeability and filtration efficiency are considered, the most desirable configuration for personal protection equipment (PPE) is NF/MOF/NW system, which effectively enabled comfortable breathing without compromising the lightweight and multifunctional performance.


Assuntos
Estruturas Metalorgânicas , Nanofibras , Filtração/métodos , Gases , Material Particulado
8.
J Med Internet Res ; 24(4): e28114, 2022 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-35451980

RESUMO

BACKGROUND: Advances in biomedical research using deep learning techniques have generated a large volume of related literature. However, there is a lack of scientometric studies that provide a bird's-eye view of them. This absence has led to a partial and fragmented understanding of the field and its progress. OBJECTIVE: This study aimed to gain a quantitative and qualitative understanding of the scientific domain by analyzing diverse bibliographic entities that represent the research landscape from multiple perspectives and levels of granularity. METHODS: We searched and retrieved 978 deep learning studies in biomedicine from the PubMed database. A scientometric analysis was performed by analyzing the metadata, content of influential works, and cited references. RESULTS: In the process, we identified the current leading fields, major research topics and techniques, knowledge diffusion, and research collaboration. There was a predominant focus on applying deep learning, especially convolutional neural networks, to radiology and medical imaging, whereas a few studies focused on protein or genome analysis. Radiology and medical imaging also appeared to be the most significant knowledge sources and an important field in knowledge diffusion, followed by computer science and electrical engineering. A coauthorship analysis revealed various collaborations among engineering-oriented and biomedicine-oriented clusters of disciplines. CONCLUSIONS: This study investigated the landscape of deep learning research in biomedicine and confirmed its interdisciplinary nature. Although it has been successful, we believe that there is a need for diverse applications in certain areas to further boost the contributions of deep learning in addressing biomedical research problems. We expect the results of this study to help researchers and communities better align their present and future work.


Assuntos
Pesquisa Biomédica , Aprendizado Profundo , Bibliometria , Humanos , Metadados , Redes Neurais de Computação , Publicações
9.
New Phytol ; 230(2): 793-803, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33459359

RESUMO

Herbivore-induced plant volatiles (HIPVs) are widely recognized as an ecologically important defensive response of plants against herbivory. Although the induction of this 'cry for help' has been well documented, only a few studies have investigated the inhibition of HIPVs by herbivores and little is known about whether herbivores have evolved mechanisms to inhibit the release of HIPVs. To examine the role of herbivore effectors in modulating HIPVs and stomatal dynamics, we conducted series of experiments combining pharmacological, surgical, genetic (CRISPR-Cas9) and chemical (GC-MS analysis) approaches. We show that the salivary enzyme, glucose oxidase (GOX), secreted by the caterpillar Helicoverpa zea on leaves, causes stomatal closure in tomato (Solanum lycopersicum) within 5 min, and in both tomato and soybean (Glycine max) for at least 48 h. GOX also inhibits the emission of several HIPVs during feeding by H. zea, including (Z)-3-hexenol, (Z)-jasmone and (Z)-3-hexenyl acetate, which are important airborne signals in plant defenses. Our findings highlight a potential adaptive strategy where an insect herbivore inhibits plant airborne defenses during feeding by exploiting the association between stomatal dynamics and HIPV emission.


Assuntos
Mariposas , Compostos Orgânicos Voláteis , Animais , Herbivoria , Insetos , Estômatos de Plantas
10.
Proc Natl Acad Sci U S A ; 115(26): 6566-6571, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29891684

RESUMO

Despite their potential to exceed the theoretical Shockley-Queisser limit, ferroelectric photovoltaics (FPVs) have performed inefficiently due to their extremely low photocurrents. Incorporating Bi2FeCrO6 (BFCO) as the light absorber in FPVs has recently led to impressively high and record photocurrents [Nechache R, et al. (2015) Nat Photonics 9:61-67], which has revived the FPV field. However, our understanding of this remarkable phenomenon is far from satisfactory. Here, we use first-principles calculations to determine that such excellent performance mainly lies in the efficient separation of electron-hole (e-h) pairs. We show that photoexcited electrons and holes in BFCO are spatially separated on the Fe and Cr sites, respectively. This separation is much more pronounced in disordered BFCO phases, which adequately explains the observed exceptional PV responses. We further establish a design strategy to discover next-generation FPV materials. By exploring 44 additional Bi-based double-perovskite oxides, we suggest five active-layer materials that offer a combination of strong e-h separations and visible-light absorptions for FPV applications. Our work indicates that charge separation is the most important issue to be addressed for FPVs to compete with conventional devices.

11.
Small ; 16(38): e2002120, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32812375

RESUMO

A challenge in the synthesis of single-wall carbon nanotubes (SWCNTs) is the lack of control over the formation and evolution of catalyst nanoparticles and the lack of control over their size or chirality. Here, zeolite MFI nanosheets (MFI-Ns) are used to keep cobalt (Co) nanoparticles stable during prolonged annealing conditions. Environmental transmission electron microscopy (ETEM) shows that the MFI-Ns can influence the size and shape of nanoparticles via particle/support registry, which leads to the preferential docking of nanoparticles to four or fewer pores and to the regulation of the SWCNT synthesis products. The resulting SWCNT population exhibits a narrow diameter distribution and SWCNTs of nearly all chiral angles, including sub-nm zigzag (ZZ) and near-ZZ tubes. Theoretical simulations reveal that the growth of these unfavorable tubes from unsupported catalysts leads to the rapid encapsulation of catalyst nanoparticles bearing them; their presence in the growth products suggests that the MFI-Ns prevent nanoparticle encapsulation and prologue ZZ and near-ZZ SWCNT growth. These results thus present a path forward for controlling nanoparticle formation and evolution, for achieving size- and shape-selectivity at high temperature, and for controlling SWCNT synthesis.

12.
Pestic Biochem Physiol ; 165: 104552, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359537

RESUMO

The fruit fly, Drosophila melanogaster, is predominantly found in overripe, rotten, fermenting, or decaying fruits and is constantly exposed to chemical stressors such as acetic acid, ethanol, and 2-phenylethanol. D. melanogaster has been employed as a model system for studying the molecular bases of various types of chemical-induced tolerance. Expression profiling using Illumina sequencing has been performed for identifying changes in gene expression that may be associated with evolutionary adaptation to exposure of acetic acid, ethanol, and 2-phenylethanol. We identified a total of 457 differentially expressed genes that may affect sensitivity or tolerance to three chemicals in the chemical treatment group as opposed to the control group. Gene-set enrichment analysis revealed that the genes involved in metabolism, multicellular organism reproduction, olfaction, regulation of signal transduction, and stress tolerance were over-represented in response to chemical exposure. Furthermore, we also detected a coordinated upregulation of genes in the Toll- and Imd-signaling pathways after the chemical exposure. Quantitative reverse transcription PCR analysis revealed that the expression levels of nine genes within the set of genes identified by RNA sequencing were up- or downregulated owing to chemical exposure. Taken together, our data suggest that such differentially expressed genes are coordinately affected by chemical exposure. Transcriptional analyses after exposure of D. melanogaster with three chemicals provide unique insights into subsequent functional studies on the mechanisms underlying the evolutionary adaptation of insect species to environmental chemical stressors.


Assuntos
Ácido Acético , Drosophila melanogaster , Animais , Drosophila , Etanol , Perfilação da Expressão Gênica , Álcool Feniletílico
13.
J Vasc Interv Radiol ; 30(3): 370-379.e4, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30819479

RESUMO

PURPOSE: To evaluate the effects of the degree of ethiodized oil accumulation achieved by transarterial chemoembolization followed by radiofrequency (RF) ablation on the treatment efficacy for a single intermediate-sized hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 153 consecutive patients who underwent chemoembolization and RF ablation for a single intermediate-sized HCC (2-5 cm) were included. On the basis of the degree of ethiodized oil accumulation in HCC on cone-beam CT images, patients who underwent chemoembolization and RF ablation were classified into 2 groups: compact accumulation (≥ 75%) and noncompact accumulation (< 75%). The rates of cumulative local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between groups. RESULTS: Of the 153 patients, 89 were classified into the compact ethiodized oil accumulation group and 64 in the noncompact ethiodized oil accumulation group. There were no significant differences in patient demographic or HCC characteristics between groups except for the incidence of liver cirrhosis (P = .038) and the tumor margin morphology (P = .008). The cumulative LTP rate was significantly lower in the compact accumulation group than in the noncompact accumulation group (P = .013). There were no significant differences in the incidences of complications, DFS rates (P = .055), or OS rates (P = .184). CONCLUSIONS: The degree of ethiodized oil accumulation does not play a role in decreasing the OS or DFS rate after chemoembolization and RF ablation for intermediate-sized HCC; however, it may contribute to reducing the rate of LTP.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Óleo Etiodado/administração & dosagem , Neoplasias Hepáticas/terapia , Ablação por Radiofrequência , Idoso , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/efeitos adversos , Quimioembolização Terapêutica/mortalidade , Tomografia Computadorizada de Feixe Cônico , Óleo Etiodado/efeitos adversos , Óleo Etiodado/metabolismo , Feminino , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Ablação por Radiofrequência/efeitos adversos , Ablação por Radiofrequência/mortalidade , República da Coreia , Estudos Retrospectivos , Fatores de Tempo , Distribuição Tecidual , Carga Tumoral
14.
Gen Comp Endocrinol ; 278: 42-49, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30077796

RESUMO

Ticks can survive in harsh and fluctuating vegetated environments for long durations between blood feedings with highly developed osmoregulatory mechanisms. Like the unique life history of hematophagous ticks, osmoregulatory organs and their regulatory mechanisms are significantly different from those in the closely related insect taxa. Over the last ten years, research has uncovered several neuropeptidergic innervations of the primary osmoregulatory organ, the salivary glands: myoinhibitory peptide (MIP), SIFamide, and elevenin. These neuropeptides are thought to be modulators of dopamine's autocrine or paracrine actions controlling the salivary glands, including the activation of fluid transport into the lumen of salivary acini and the pumping and gating action of salivary acini for expelling fluids out into salivary ducts. These actions are through two different dopamine receptors, D1 receptor and invertebrate D1-like dopamine receptor, respectively. Interestingly, MIP and SIFamide are also involved in the control of another important excretory/osmoregulatory organ, the hindgut, where SIFamide is myostimulatory, with MIP having antagonistic effects. FGLamide related allatostatin is also found to have axonal projections located on the surface of the rectum. Investigations of the osmoregulatory mechanisms of these critical vector species will potentially lead to the development of a measure to control tick species.


Assuntos
Sistema Endócrino/metabolismo , Ixodes/metabolismo , Neurônios/metabolismo , Especificidade de Órgãos , Osmorregulação , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Dopamina/metabolismo , Corantes Fluorescentes/metabolismo , Modelos Biológicos , Glândulas Salivares/metabolismo
15.
Angew Chem Int Ed Engl ; 57(2): 480-485, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29194920

RESUMO

The control of membrane morphology and microstructure is crucial to improve the separation performance of molecular-sieve membranes. This can be enabled by making thin, dense, and uniform seed-crystal coatings, which are then intergrown into continuous membranes. Herein, we show a novel and simple floating particle coating method can give closely packed monolayers of zeolite nanosheets on nonporous or porous supports. The zeolite nanosheet monolayer is formed at the air-water interface in a conical Teflon trough. As the water in the trough is drained, the monolayer is deposited on a support placed below. Membranes prepared by gel-free secondary growth of the nanosheets deposited by this method show unprecedented ultra-selective performance for separation of para- from ortho-xylene (separation factor >10 000).

16.
Angew Chem Int Ed Engl ; 56(2): 535-539, 2017 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-27936290

RESUMO

Nanoscale crystal growth control is crucial for tailoring two-dimensional (2D) zeolites (crystallites with thickness less than two unit cells) and thicker zeolite nanosheets for applications in separation membranes and as hierarchical catalysts. However, methods to control zeolite crystal growth with nanometer precision are still in their infancy. Herein, we report solution-based growth conditions leading to anisotropic epitaxial growth of 2D zeolites with rates as low as few nanometers per day. Contributions from misoriented surface nucleation and rotational intergrowths are eliminated. Growth monitoring at the single-unit-cell level reveals novel nanoscale crystal-growth phenomena associated with the lateral size and surface curvature of 2D zeolites.

17.
Biosci Biotechnol Biochem ; 80(8): 1478-83, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27108675

RESUMO

Although biological synthesis methods for the production of gold structures by microorganisms, plant extracts, proteins, and peptide have recently been introduced, there have been few reports pertaining to controlling their size and morphology. The gold ion and peptide concentrations affected on the size and uniformity of gold plates by a gold-binding peptide Midas-11. The higher concentration of gold ions produced a larger size of gold structures reached 125.5 µm, but an increased amount of Midas-11 produced a smaller size of gold platelets and increased the yield percentage of polygonal gold particles rather than platelets. The mechanisms governing factors controlling the production of gold structures were primarily related to nucleation and growth. These results indicate that the synthesis of gold architectures can be controlled by newly isolated and substituted peptides under different reaction conditions.


Assuntos
Materiais Biomiméticos/química , Cloretos/química , Compostos de Ouro/química , Ouro/química , Peptídeos/química , Concentração de Íons de Hidrogênio , Íons , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Ligação Proteica
18.
J Clin Lab Anal ; 30(6): 930-940, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27075615

RESUMO

BACKGROUND: High C-reactive protein (CRP) and mean platelet volume (MPV) levels are associated with poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to evaluate the relationship between CRP level or MPV and infarct transmurality in patients with STEMI. METHODS: We retrospectively reviewed CRP level, MPV, and infarct transmurality in 112 STEMI patients who were assessed with contrast-enhanced cardiac magnetic resonance imaging. RESULTS: When the cut-off peak CRP level and MPV were set at 2.35 mg/dl and 7.3 fl using receiver operating characteristic curves analysis, the sensitivity was 67.3/69.2% and specificity was 76.7/76.7% for differentiating between the groups with and those without transmural involvement. Peak CRP level, MPV, peak creatine kinase-MB (CK-MB) level, and peak high-sensitivity cardiac troponin T (hs-cTnT) level had comparable predictive values for transmural involvement (area under the curve, 0.749, 0.761, 0.680, and 0.696, respectively). High peak CRP level and MPV were independent predictors of transmural involvement after adjusting for the peak CK-MB level, peak hs-cTnT level, baseline thrombolysis in myocardial infarction flow grade, and left ventricular ejection fraction (odds ratio: 5.16/5.42, 95% confidence interval: 1.84-14.50/2.03-14.47, P = 0.002/0.001, respectively) in the logistic regression analysis. CONCLUSION: The results of this study show that peak CRP level and MPV are predictive markers for transmural involvement. Their predictive power for transmural involvement is independent of and comparable to that of peak CK-MB and hs-cTnT levels.


Assuntos
Proteína C-Reativa/metabolismo , Volume Plaquetário Médio , Miocárdio/patologia , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Idoso , Estudos de Coortes , Meios de Contraste , Creatina Quinase/metabolismo , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/métodos , Valor Preditivo dos Testes , Curva ROC , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia , Estatísticas não Paramétricas , Troponina T
19.
Angew Chem Int Ed Engl ; 54(5): 1561-4, 2015 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-25504599

RESUMO

Copper-amyloid peptides are proposed to be the cause of Alzheimer's disease, presumably by oxidative stress. However, mice do not produce amyloid plaques and thus do not suffer from Alzheimer's disease. Although much effort has been focused on the structural characterization of the copper- human amyloid peptides, little is known regarding the copper-binding mode in murine amyloid peptides. Thus, we investigated the structure of copper-murine amyloid peptides through multi-frequency, multi-technique pulsed EPR spectroscopy in conjunction with specific isotope labeling. Based on our pulsed EPR results, we found that Ala2, Glu3, His6, and His14 are directly coordinated with the copper ion in murine amyloid ß peptides at pH 8.5. This is the first detailed structural characterization of the copper-binding mode in murine amyloid ß peptides. This work may advance the knowledge required for developing inhibitors of Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/química , Cobre/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Sítios de Ligação , Cobre/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Concentração de Íons de Hidrogênio , Camundongos , Ligação Proteica
20.
J Am Chem Soc ; 136(20): 7435-43, 2014 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-24758237

RESUMO

The development of a water oxidation catalyst has been a demanding challenge in realizing water splitting systems. The asymmetric geometry and flexible ligation of the biological Mn4CaO5 cluster are important properties for the function of photosystem II, and these properties can be applied to the design of new inorganic water oxidation catalysts. We identified a new crystal structure, Mn3(PO4)2·3H2O, that precipitates spontaneously in aqueous solution at room temperature and demonstrated its high catalytic performance under neutral conditions. The bulky phosphate polyhedron induces a less-ordered Mn geometry in Mn3(PO4)2·3H2O. Computational analysis indicated that the structural flexibility in Mn3(PO4)2·3H2O could stabilize the Jahn-Teller-distorted Mn(III) and thus facilitate Mn(II) oxidation. This study provides valuable insights into the interplay between atomic structure and catalytic activity.

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