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1.
Nature ; 616(7957): 482-487, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37076728

RESUMO

Partitioning of americium from lanthanides (Ln) present in used nuclear fuel plays a key role in the sustainable development of nuclear energy1-3. This task is extremely challenging because thermodynamically stable Am(III) and Ln(III) ions have nearly identical ionic radii and coordination chemistry. Oxidization of Am(III) to Am(VI) produces AmO22+ ions distinct with Ln(III) ions, which has the potential to facilitate separations in principle. However, the rapid reduction of Am(VI) back to Am(III) by radiolysis products and organic reagents required for the traditional separation protocols including solvent and solid extractions hampers practical redox-based separations. Herein, we report a nanoscale polyoxometalate (POM) cluster with a vacancy site compatible with the selective coordination of hexavalent actinides (238U, 237Np, 242Pu and 243Am) over trivalent lanthanides in nitric acid media. To our knowledge, this cluster is the most stable Am(VI) species in aqueous media observed so far. Ultrafiltration-based separation of nanoscale Am(VI)-POM clusters from hydrated lanthanide ions by commercially available, fine-pored membranes enables the development of a once-through americium/lanthanide separation strategy that is highly efficient and rapid, does not involve any organic components and requires minimal energy input.

2.
Nano Lett ; 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39361493

RESUMO

Time reversal symmetry breaking in superconductors, resulting from external magnetic fields or spontaneous magnetization, often leads to unconventional superconducting properties. In this way, an intrinsic phenomenon called the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state may be realized by the Zeeman effect. Here, we construct the FFLO state in an artificial CrOCl/NbSe2 van der Waals (vdW) heterostructure by utilizing the superconducting proximity effect of NbSe2 flakes. The proximity-induced superconductivity demonstrates a considerably weak gap of about 0.12 meV, and the in-plane upper critical field reveals the behavior of the FFLO state. First-principles calculations uncover the origin of the proximitized superconductivity, which indicates the importance of Cr vacancies or line defects in CrOCl. Moreover, the FFLO state could be induced by the inherent large spin splitting in CrOCl. Our findings not only provide a practical scheme for constructing the FFLO state but also inspire the discovery of an exotic FFLO state in other two-dimensional vdW heterostructures.

3.
Nano Lett ; 23(12): 5770-5778, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37314049

RESUMO

Understanding the atomistic mechanisms of non-equilibrium processes during solid-state synthesis, such as nucleation and grain structure formation of a layered oxide phase, is a critical challenge for developing promising cathode materials such as Ni-rich layered oxide for Li-ion batteries. In this study, we found that the aluminum oxide coating layer transforms into lithium aluminate as an intermediate, which has favorable low interfacial energies with the layered oxide to promote the nucleation of the latter. The fast and uniform nucleation and formation of the layered oxide phase at relatively low temperatures were evidenced using solid-state nuclear magnetic resonance and in situ synchrotron X-ray diffraction. The resulting Ni-rich layered oxide cathode has fine primary particles, as visualized by three-dimensional tomography constructed using a focused-ion beam and scanning electron microscopy. The densely packed fine primary particles enable the excellent mechanical strength of the secondary particles, as demonstrated by in situ compression tests. This strategy provides a new approach for developing next-generation, high-strength battery materials.

4.
Nano Lett ; 23(9): 4066-4073, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37097764

RESUMO

Reticular chemistry provides opportunities to design solid-state electrolytes (SSEs) with modular tunability. However, SSEs based on modularly designed crystalline metal-organic frameworks (MOFs) often require liquid electrolytes for interfacial contact. Monolithic glassy MOFs can have liquid processability and uniform lithium conduction, which is promising for the reticular design of SSE without liquid electrolytes. Here, we develop a generalizable strategy for the modular design of noncrystalline SSEs based on a bottom-up synthesis of glassy MOFs. We demonstrate such a strategy by linking polyethylene glycol (PEG) struts and nanosized titanium-oxo clusters into network structures termed titanium alkoxide networks (TANs). The modular design allows the incorporation of PEG linkers with different molecular weights, which give optimal chain flexibility for high ionic conductivity, and the reticular coordinative network provides a controlled degree of cross-linking that gives adequate mechanical strength. This research shows the power of reticular design in noncrystalline molecular framework materials for SSEs.

5.
Angew Chem Int Ed Engl ; : e202409169, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39171425

RESUMO

Natural dissipative assembly (DSA) often exhibit energy-driven shifts in natural functions. However, creating man-made DSA that can mimic such biological activities transformation remains relatively rare. Herein, we introduce a cytomembrane-like dissipative assembly system based on chiral supramolecules. This system employs benzoyl cysteine in an out of equilibrium manner, enabling the shifts in biofunctions while minimizing material use. Specifically, aroyl-cystine derivatives primarily assemble into stable M-helix nanofibers under equilibrium conditions. These nanofibers enhance fibroblast adhesion and proliferation through stereospecific interactions with chiral cellular membranes. Upon the addition of chemical fuels, these functional nanofibers temporarily transform into non-equilibrium nanospheres, facilitating efficient drug delivery. Subsequently, these nanospheres revert to their original nanofiber state, effectively recycling the drug. The programmable function-shifting ability of this DSA establishes it as a novel, fuel-driven drug delivery vehicle. And the bioactive DSA not only addresses a gap in synthetic DSAs within biological applications but also sets the stage for innovative designs of 'living' materials.

6.
Angew Chem Int Ed Engl ; : e202417658, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39354679

RESUMO

Metal-organic frameworks (MOFs) have been widely studied due to their versatile applications and easily tunable structures. However, heteroatom-metal coordination dominates the MOFs community, and the rational synthesis of carbon-metal coordination-based MOFs remains a significant challenge. Herein, two-dimensional (2D) MOFs based on silver-carbon linkages are synthesized through the coordination between silver(I) salt and isocyanide-based monomers at ambient condition. The as-synthesized 2D MOFs possess well-defined crystalline structures and a staggered AB stacking mode. Most interestingly, these 2D MOFs, without π-π stacking between layers, exhibit narrow band gaps down to 1.42 eV. As electrochemical catalysts for converting CO2 to CO, such 2D MOFs demonstrate Faradaic efficiency over 92 %. Surprisingly, the CO2 reduction catalyzed by these MOFs indicates favorable adsorption of CO2 and *COOH on the active carbon sites of the isocyanide groups rather than on silver sites. This is attributed to the critical σ donor role of isocyanides and the corresponding ligand-to-metal charge-transfer effect. This work not only paves the way toward a new family of MOFs based on metal-isocyanide coordination but also offers a rare platform for understanding the electrocatalysis processes on strongly polarized carbon species.

7.
J Am Chem Soc ; 145(11): 6184-6193, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36893194

RESUMO

Hexagonal boron nitride (h-BN) is regarded as one of the most efficient catalysts for oxidative dehydrogenation of propane (ODHP) with high olefin selectivity and productivity. However, the loss of the boron component under a high concentration of water vapor and high temperature seriously hinders its further development. How to make h-BN a stable ODHP catalyst is one of the biggest scientific challenges at present. Herein, we construct h-BN⊃xIn2O3 composite catalysts through the atomic layer deposition (ALD) process. After high-temperature treatment in ODHP reaction conditions, the In2O3 nanoparticles (NPs) are dispersed on the edge of h-BN and observed to be encapsulated by ultrathin boron oxide (BOx) overlayer. A novel strong metal oxide-support interaction (SMOSI) effect between In2O3 NPs and h-BN is observed for the first time. The material characterization reveals that the SMOSI not only improves the interlayer force between h-BN layers with a pinning model but also reduces the affinity of the B-N bond toward O• for inhibiting oxidative cutting of h-BN into fragments at a high temperature and water-rich environment. With the pinning effect of the SMOSI, the catalytic stability of h-BN⊃70In2O3 has been extended nearly five times than that of pristine h-BN, and the intrinsic olefin selectivity/productivity of h-BN is well maintained.

8.
J Am Chem Soc ; 145(49): 26871-26882, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-37968832

RESUMO

Two-dimensional (2D) covalent organic frameworks (COFs) with hierarchical porosity have been increasingly recognized as promising materials in various fields. Besides, the 2D COFs with kagome (kgm) topology can exhibit unique optoelectronic features and have extensive applications. However, rational synthesis of the COFs with kgm topology remains challenging because of competition with a square-lattice topology. Herein, we report two isomeric dual-pore 2D COFs with kgm topology using a novel geometric strategy to reduce the symmetry of their building blocks, which are four-armed naphthalene-based and azulene-based isomeric monomers. Owing to the large dipole moment of azulene, as-prepared azulene-based COF (COF-Az) possesses a considerably narrow band gap of down to 1.37 eV, which is much narrower than the naphthalene-based 2D COF (COF-Nap: 2.28 eV) and is the lowest band gap among reported imine-linked dual-pore 2D COFs. Moreover, COF-Az was used as electrode material in a gas sensor and exhibits high selectivity for NO2, including a high response rate (58.7%) to NO2 (10 ppm), fast recovery (72 s), up to 10 weeks of stability, and resistance to 80% relative humidity, which are superior to those of reported COF-based NO2 gas sensors. The calculation and in situ experimental results indicate that the large dipole moment of azulene boosts the sensitivity of the imine linkages. The usage of isomeric building blocks not only enables the synthesis of 2D COFs with isometric kgm topology but also provides an azulene-based 2D platform for studying the structure-property correlations of COFs.

9.
Glob Chang Biol ; 29(16): 4569-4585, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36880889

RESUMO

Biodiversity is essential for maintaining the terrestrial ecosystem multifunctionality (EMF). Recent studies have revealed that the variations in terrestrial ecosystem functions are captured by three key axes: the maximum productivity, water use efficiency, and carbon use efficiency of the ecosystem. However, the role of biodiversity in supporting these three key axes has not yet been explored. In this study, we combined the (i) data collected from more than 840 vegetation plots across a large climatic gradient in China using standard protocols, (ii) data on plant traits and phylogenetic information for more than 2,500 plant species, and (iii) soil nutrient data measured in each plot. These data were used to systematically assess the contribution of environmental factors, species richness, functional and phylogenetic diversity, and community-weighted mean (CWM) and ecosystem traits (i.e., traits intensity normalized per unit land area) to EMF via hierarchical partitioning and Bayesian structural equation modeling. Multiple biodiversity attributes accounted for 70% of the influence of all the variables on EMF, and ecosystems with high functional diversity had high resource use efficiency. Our study is the first to systematically explore the role of different biodiversity attributes, including species richness, phylogenetic and functional diversity, and CWM and ecosystem traits, in the key axes of ecosystem functions. Our findings underscore that biodiversity conservation is critical for sustaining EMF and ultimately ensuring human well-being.


Assuntos
Biodiversidade , Ecossistema , Humanos , Filogenia , Teorema de Bayes , Água , Solo
10.
BMC Cancer ; 23(1): 176, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36809979

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is associated with a high occurrence, mortality, and poor prognosis. MLX interacting protein like (MLXIPL) is an important regulator of glucolipid metabolism and is involved in tumor progression. We aimed to clarify the role of MLXIPL in HCC and its underlying mechanisms. METHODS: The level of MLXIPL was predicted using bioinformatic analysis and verified using quantitative real-time PCR (qPCR), immunohistochemical analysis, and western blot. We assessed the effects of MLXIPL on biological behaviors using the cell counting kit-8, colony formation, and Transwell assay. Glycolysis was evaluated using the Seahorse method. The interaction between MLXIPL and mechanistic target of rapamycin kinase (mTOR) was confirmed using RNA immunoprecipitation and co-immunoprecipitation. mTOR expression was detected in HCC cells using qPCR, immunofluorescence analysis, and western blot. RESULTS: The results showed that MLXIPL levels were elevated in both HCC tissues and HCC cell lines. Knockdown of MLXIPL impeded HCC cell growth, invasion, migration, and glycolysis. Moreover, MLXIPL combined with mTOR to induce phosphorylation of mTOR. Activated mTOR abrogated the effects on cellular processes induced by MLXIPL. CONCLUSION: MLXIPL promoted the malignant progression of HCC by activating phosphorylation of mTOR, suggesting an important role of the combination of MLXIPL and mTOR in HCC.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Serina-Treonina Quinases TOR , Humanos , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glicólise , Neoplasias Hepáticas/patologia , Processos Neoplásicos , Fosforilação , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo
11.
Clin Gastroenterol Hepatol ; 19(10): 2205-2206, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33065310

RESUMO

Microscopic colitis (MC) is a chronic inflammatory disease of the colon that presents with chronic, nonbloody watery diarrhea and only few or no endoscopic abnormalities. Histologic examination discriminates lymphocytic colitis (LyC; presence of ≥20 intraepithelial lymphocytes per 100 surface epithelial cells) and collagenous colitis (CC; colonic subepithelial collagen band >10 µm in diameter).1,2 MC not otherwise specified describes a subgroup of patients who do not fulfill the diagnostic criteria for either CC or LyC.1,2 Population-based epidemiologic data regarding MC are scarce. We aimed to evaluate the clinical presentation at diagnosis, incidence, and prevalence of MC in Cantons of Vaud and Fribourg, Switzerland.


Assuntos
Colite Colagenosa , Colite Linfocítica , Colite Microscópica , Colite , Estudos de Coortes , Colite Microscópica/diagnóstico , Colite Microscópica/epidemiologia , Humanos , Incidência , Suíça/epidemiologia
12.
Chin J Traumatol ; 24(4): 187-208, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33994278

RESUMO

There has been a long history since human beings began to realize the existence of post-traumatic symptoms. Posttraumatic stress disorder (PTSD), a diagnostic category adopted in 1980 in the Diagnostic and Statistical Manual of Mental Disorders-Ⅲ, described typical clusters of psychiatric symptoms occurring after traumatic events. Abundant researches have helped deepen the understanding of PTSD in terms of epidemiological features, biological mechanisms, and treatment options. The prevalence of PTSD in general population ranged from 6.4% to 7.8% and was significantly higher among groups who underwent major public traumatic events. There has been a long way in the studies of animal models and genetic characteristics of PTSD. However, the high comorbidity with other stress-related psychiatric disorders and complexity in the pathogenesis of PTSD hindered the effort to find specific biological targets for PTSD. Neuroimage was widely used to elucidate the underlying neurophysiological mechanisms of PTSD. Functional MRI studies have showed that PTSD was linked to medial prefrontal cortex, anterior cingulate cortex and sub-cortical structures like amygdala and hippocampus, and to explore the functional connectivity among these brain areas which might reveal the possible neurobiological mechanism related to PTSD symptoms. For now, cognitive behavior therapy-based psychotherapy, including combination with adjunctive medication, showed evident treatment effects on PTSD. The emergence of more effective PTSD pharmacotherapies awaits novel biomarkers from further fundamental research. Several natural disasters and emergencies have inevitably increased the possibility of suffering from PTSD in the last two decades, making it critical to strengthen PTSD research in China. To boost PTSD study in China, the following suggestions might be helpful: (1) establishing a national psychological trauma recover project, and (2) exploring the mechanisms of PTSD with joint effort and strengthening the indigenized treatment of PTSD.


Assuntos
Transtornos de Estresse Pós-Traumáticos , Animais , Encéfalo , Comorbidade , Hipocampo , Humanos , Imageamento por Ressonância Magnética , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/terapia
13.
Chin J Traumatol ; 24(4): 221-230, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34099359

RESUMO

PURPOSE: Posttraumatic stress disorder (PTSD) is a significant global mental health concern, especially in the military. This study aims to estimate the efficacy of mindfulness meditation in the treatment of military-related PTSD, by synthesizing evidences from randomized controlled trials. METHODS: Five electronic databases (Pubmed, EBSCO Medline, Embase, PsychINFO and Cochrane Library) were searched for randomized controlled trials focusing on the treatment effect of mindfulness meditation on military-related PTSD. The selection of eligible studies was based on identical inclusion and exclusion criteria. Information about study characteristics, participant characteristics, intervention details, PTSD outcomes, as well as potential adverse effects was extracted from the included studies. Risk of bias of all the included studies was critically assessed using the Cochrane Collaboration's tool. R Statistical software was performed for data analysis. RESULTS: A total of 1902 records were initially identified and screened. After duplicates removal and title & abstract review, finally, 19 articles in English language with 1326 participants were included through strict inclusion and exclusion criteria. The results revealed that mindfulness meditation had a significantly larger effect on alleviating military-related PTSD symptoms compared with control conditions, such as treatment as usual, present-centered group therapy and PTSD health education (standardized mean difference (SMD) = -0.33; 95% CI [-0.45, -0.21]; p < 0.0001). Mindfulness interventions with different control conditions (active or non-active control, SMD = -0.33, 95% CI [-0.46, -0.19]; SMD = -0.49, 95% CI [-0.88, -0.10], respectively), formats of delivery (group-based or individual-based, SMD = -0.30, 95% CI [-0.42, -0.17], SMD = -0.49, 95% CI [-0.90, -0.08], respectively) and intervention durations (short-term or standard duration, SMD = -0.27, 95% CI [-0.46, -0.08], SMD = -0.40, 95% CI [-0.58, -0.21], respectively) were equally effective in improving military-related PTSD symptoms. CONCLUSION: Findings from this meta-analysis consolidate the efficacy and feasibility of mindfulness meditation in the treatment of military-related PTSD. Further evidence with higher quality and more rigorous design is needed in the future.


Assuntos
Terapia Cognitivo-Comportamental , Meditação , Militares , Atenção Plena , Transtornos de Estresse Pós-Traumáticos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Transtornos de Estresse Pós-Traumáticos/terapia
14.
Int J Cancer ; 146(1): 103-114, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31199508

RESUMO

Next-generation sequencing of cell-free circulating DNA (cfDNA) has emerged as promising technique for identifying minimally invasive genomic profiling of tumor cells recently. However, it remains relatively unknown in LAM disease. In our study, paired cfDNA and genomic DNA (gDNA) in blood samples were obtained from 23 LAM patients and seven healthy controls to explore mutations profiles of targeted 70 cancer-related genes. As results, log2-based allele frequencies of mutations in cfDNA were significantly different from those of gDNA. By comparing the mutual mutations identified both in cfDNA and gDNA, a significant correlation was also observed. After removing mutations in gDNA, distinct somatic mutation profiles of cfDNA were observed in LAM patients. Forty of 70 targeted genes had recurrent mutations, of which ATM, BRCA2 and APC showed the highest frequency. Based on the mutation, correlation network constructed of 40 mutated genes, 11 hub genes bearing intensive interactions were highlighted, including BRCA1, BRCA2, RAD50, RB1, NF1, APC, MLH3, ATM, PDGFRA, PALB2 and BLM. Expression of the hub genes showed significant clusters between LAM patients and controls and that RAD50 and BRCA2 had the strongest associations with subject phenotypes. Myogenesis and estrogen response were confirmed to be positively regulated in LAM patients. Collectively, our study provided a landscape of genomic alterations in LAM and discovered several potential driver genes, that is, BRCA2 and RAD50, which shed a substantial light on the clinical application of key molecular markers and potential therapy targets for precision diagnosis and treatment in the future.


Assuntos
Ácidos Nucleicos Livres/genética , Neoplasias Pulmonares/genética , Linfangioleiomiomatose/genética , Mutação/genética , Adulto , Proteína BRCA2/genética , DNA Tumoral Circulante/genética , DNA de Neoplasias/genética , Proteínas de Ligação a DNA/genética , Feminino , Frequência do Gene/genética , Genoma/genética , Genômica/métodos , Humanos , Masculino , Pessoa de Meia-Idade
15.
Phytopathology ; 110(1): 187-193, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31516080

RESUMO

Potyviral helper component protease (HC-Pro), as a major determinant of symptom expression in susceptible plants, is a likely target candidate in the production of attenuated strains for cross-protection. In this study, single or double mutations of Lys (K) to Glu (E) in the Lys-Ile-Thr-Cys motif and Arg (R) to Ile (I) in the Phe-Arg-Asn-Lys motif of the HC-Pro from the severe papaya leaf distortion mosaic virus strain DF (PLDMV-DF) reduced symptom expression and virus accumulation in infected papaya (Carica papaya) plants. The papaya plants infected with the attenuated double mutant of PLDMV-EI presented as symptomless. PLDMV-EI provided effective protection against PLDMV-DF infection in three papaya cultivars and had no effect on plant growth and development. Our result showed that PLDMV-EI is a promising mild strain for the practical use of cross-protection in the field.


Assuntos
Motivos de Aminoácidos , Carica , Peptídeo Hidrolases , Potyvirus , Motivos de Aminoácidos/genética , Carica/virologia , Mutação/genética , Peptídeo Hidrolases/genética , Potyvirus/enzimologia , Potyvirus/genética
16.
Protein Expr Purif ; 146: 17-22, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29373846

RESUMO

Plant methionine sulfoxide reductase B1 (MsrB1) protects the photosynthetic apparatus from oxidative damage by scavenging reactive oxygen species to repair Met-oxidized proteins in response to abiotic stresses and biotic attack. Papaya MsrB1 (PaMsrB1) was identified previously to interact with papaya ringspot virus NIa-Pro, and this interaction inhibits the import of PaMsrB1 into the chloroplast. Further functional characterization of PaMsrB1 requires the production of a biologically active purified recombinant protein. In this report, PaMsrB1 as a fusion protein containing an N-terminal maltose-binding protein (MBP) was expressed in Escherichia coli Rosetta (DE3) cells and purified. Production of soluble fusion protein was greater when the cells were cultured at 16 °C than at 37 °C. The Factor Xa protease digested MBP-PaMsrB1 fusion protein and subsequently purified recombinant PaMsrB1 specifically reduced the R-diastereomer of methionine sulfoxide (MetSO) and Dabsyl-MetSO to Met in the presence of dithiothreitol. Eight chloroplast-localized and five non-chloroplast-localized candidate proteins that interact with PaMsrB1 were isolated by affinity chromatography and liquid chromatography coupled to tandem mass spectrometry. The results provide a platform to further understand the anti-oxidative defense mechanism of PaMsrB1.


Assuntos
Carica/enzimologia , Metionina Sulfóxido Redutases/metabolismo , Mapas de Interação de Proteínas , Sequência de Aminoácidos , Carica/química , Carica/genética , Carica/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Escherichia coli/genética , Expressão Gênica , Metionina Sulfóxido Redutases/química , Metionina Sulfóxido Redutases/genética , Oxirredução , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Solubilidade
17.
Virus Genes ; 54(6): 833-839, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30218292

RESUMO

We used green fluorescent protein (GFP)-tagged Papaya leaf distortion mosaic virus (PLDMV-GFP) to track PLDMV infection by fluorescence. The virus-derived small interfering RNAs (vsiRNAs) of PLDMV-GFP were characterized from papaya plants by next-generation sequencing. The foreign GFP gene inserted into the PLDMV genome was also processed as a viral gene into siRNAs by components involved in RNA silencing. The siRNAs derived from PLDMV-GFP accumulated preferentially as 21- and 22-nucleotide (nt) lengths, and most of the 5'-terminal ends were biased towards uridine (U) and adenosine (A). The single-nucleotide resolution map revealed that vsiRNAs were heterogeneously distributed throughout the PLDMV-GFP genome, and vsiRNAs derived from the sense strand were more abundant than those from the antisense strand. The hotspots were mainly distributed in the P1 and GFP coding region of the antisense strand. In addition, 979 papaya genes targeted by the most abundant 1000 PLDMV-GFP vsiRNAs were predicted and annotated using GO and KEGG classification. Results suggest that vsiRNAs play key roles in PLDMV-papaya interactions. These data on the characterization of PLDMV-GFP vsiRNAs will help to provide insight into the function of vsiRNAs and their host target regulation patterns.


Assuntos
Carica/virologia , Potyvirus/isolamento & purificação , RNA Interferente Pequeno/genética , RNA Viral/genética , Carica/genética , Carica/crescimento & desenvolvimento , Genoma Viral/genética , Proteínas de Fluorescência Verde/genética , Sequenciamento de Nucleotídeos em Larga Escala , Doenças das Plantas/genética , Doenças das Plantas/virologia , Potyvirus/genética , Potyvirus/patogenicidade , Interferência de RNA
18.
Gastroenterology ; 150(3): 581-590.e4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26584601

RESUMO

BACKGROUND & AIMS: It is not clear whether symptoms alone can be used to estimate the biologic activity of eosinophilic esophagitis (EoE). We aimed to evaluate whether symptoms can be used to identify patients with endoscopic and histologic features of remission. METHODS: Between April 2011 and June 2014, we performed a prospective, observational study and recruited 269 consecutive adults with EoE (67% male; median age, 39 years old) in Switzerland and the United States. Patients first completed the validated symptom-based EoE activity index patient-reported outcome instrument and then underwent esophagogastroduodenoscopy with esophageal biopsy collection. Endoscopic and histologic findings were evaluated with a validated grading system and standardized instrument, respectively. Clinical remission was defined as symptom score <20 (range, 0-100); histologic remission was defined as a peak count of <20 eosinophils/mm(2) in a high-power field (corresponds to approximately <5 eosinophils/median high-power field); and endoscopic remission as absence of white exudates, moderate or severe rings, strictures, or combination of furrows and edema. We used receiver operating characteristic analysis to determine the best symptom score cutoff values for detection of remission. RESULTS: Of the study subjects, 111 were in clinical remission (41.3%), 79 were in endoscopic remission (29.7%), and 75 were in histologic remission (27.9%). When the symptom score was used as a continuous variable, patients in endoscopic, histologic, and combined (endoscopic and histologic remission) remission were detected with area under the curve values of 0.67, 0.60, and 0.67, respectively. A symptom score of 20 identified patients in endoscopic remission with 65.1% accuracy and histologic remission with 62.1% accuracy; a symptom score of 15 identified patients with both types of remission with 67.7% accuracy. CONCLUSIONS: In patients with EoE, endoscopic or histologic remission can be identified with only modest accuracy based on symptoms alone. At any given time, physicians cannot rely on lack of symptoms to make assumptions about lack of biologic disease activity in adults with EoE. ClinicalTrials.gov, Number: NCT00939263.


Assuntos
Esofagite Eosinofílica/diagnóstico , Esofagite Eosinofílica/terapia , Eosinófilos/patologia , Esofagoscopia , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Biópsia , Esofagite Eosinofílica/complicações , Esofagite Eosinofílica/patologia , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Indução de Remissão , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Suíça , Resultado do Tratamento , Estados Unidos , Adulto Jovem
19.
J Oral Maxillofac Surg ; 75(1): 92-104, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27637777

RESUMO

PURPOSE: Stem cell therapy is becoming a potent strategy to shorten the consolidation time and reduce potential complications during distraction osteogenesis (DO). However, the conventional local injection or scaffold-based delivery of bone marrow mesenchymal stem cell (BMSC) suspension deprives the cells of their endogenous extracellular matrix, which might dampen cell differentiation and tissue regeneration after implantation. Therefore, in our study, a BMSC sheet was established and was then minced into fragments and loaded onto a hydroxyapatite (HA) scaffold for grafting. MATERIALS AND METHODS: The purified and characterized BMSCs were grown into a cell sheet, and bone formation and mineralization capacity, as well as the cell sheet composition, were analyzed. Afterward, the in vivo osteogenic ability of cell sheet fragments (CSFs) was evaluated in immunocompromised mouse and rabbit models of DO. RESULTS: The BMSC sheet exhibited higher alkaline phosphatase activity than osteogenic cell suspension cultures. Alkaline phosphatase activity and mineral particles in the cell sheet increased further after osteogenic induction. Moreover, calcium and phosphorus were present only in the osteogenic cell sheet, along with the common elements carbon, oxygen, chlorine, sodium, and sulfur, as indicated by x-ray photoelectron spectroscopy analysis. In a mouse model, the CSF-HA complex was injected subcutaneously. Micro-computed tomography analysis showed that the osteogenic CSF-HA complex led to a considerably higher bone volume than the BMSC-HA or CSF-HA complex. The osteogenic CSF-HA specimens showed increased angiogenesis and deposition of type I collagen compared with the non-osteogenic CSF-HA or BMSC-HA specimens. Moreover, the osteogenic CSF-HA markedly improved bone consolidation and increased bone mass in DO rabbits. CONCLUSIONS: Collectively, the incorporation of osteogenic BMSC sheets into HA particles greatly promoted bone regeneration, which offers therapeutic alternatives for DO.


Assuntos
Transplante de Medula Óssea/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Osteogênese , Alicerces Teciduais , Animais , Calcificação Fisiológica , Camundongos , Coelhos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Microtomografia por Raio-X
20.
Am J Gastroenterol ; 110(3): 402-14, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25732414

RESUMO

OBJECTIVES: There is no "gold standard" for assessing disease activity in patients with eosinophilic esophagitis (EoE). We aimed to compare physicians' judgment of EoE activity with patients' judgment of symptom severity. We also aimed to examine the relative contribution of symptoms as well as endoscopic and histologic findings in shaping physicians' judgment of EoE activity. METHODS: Six gastroenterologists (all EoE experts) assessed EoE-associated symptoms in adult patients. Patients completed a symptom instrument and provided global assessment of EoE symptom severity (PatGA) (Likert scale: 0 (inactive) to 10 (most active)). Following esophagogastroduodenoscopy with biopsy sampling, gastroenterologists provided a global assessment of EoE activity (PhysGA) (Likert scale from 0 to 10) based on patient history and endoscopic and histologic findings. Linear regression and analysis of variance was used to quantify the extent to which variations in severity of EoE symptoms and endoscopic and histologic findings explain variations in PhysGA. RESULTS: A total of 149 EoE patients were prospectively included (71.8% male, median age at inclusion 38 years, 71.8% with concomitant allergies). A moderate positive correlation between PhysGA and PatGA (rho=0.442, P<0.001) was observed and the mean difference in the Bland-Altman plot was 1.77. Variations in severity of endoscopic findings, symptoms, and histologic findings alone explained 53%, 49%, and 30%, of the variability in PhysGA, respectively. Together, these findings explained 75% of variability in PhysGA. CONCLUSIONS: Gastroenterologists rate EoE activity mainly on the basis of endoscopic findings and symptoms and, to a lesser extent, on histologic findings.


Assuntos
Esofagite Eosinofílica/diagnóstico , Hipersensibilidade/complicações , Anamnese , Padrões de Prática Médica , Avaliação de Sintomas , Adulto , Análise de Variância , Autoavaliação Diagnóstica , Endoscopia do Sistema Digestório/métodos , Esofagite Eosinofílica/complicações , Esofagite Eosinofílica/fisiopatologia , Esôfago/patologia , Feminino , Humanos , Biópsia Guiada por Imagem/métodos , Masculino , Anamnese/métodos , Anamnese/normas , Anamnese/estatística & dados numéricos , Pessoa de Meia-Idade , Gravidade do Paciente , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricos , Índice de Gravidade de Doença , Estatística como Assunto , Suíça , Avaliação de Sintomas/métodos , Avaliação de Sintomas/normas , Avaliação de Sintomas/estatística & dados numéricos , Estados Unidos
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